JP2014098551A - Heat pump system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain a high temperature water medium in a heat pump system capable of heating a water medium using a heat pump cycle.SOLUTION: A heat pump system 1 includes: a heat-source-side refrigerant circuit 20 that includes a heat-source-side compressor 21, a first use-side heat exchanger 41a functioning as a radiator of a heat-source-side refrigerant, and a heat-source-side heat exchanger 24 functioning as a radiator of the heat-source-side refrigerant; and a use-side refrigerant circuit 40a that includes a use-side compressor 62a, a refrigerant-water heat exchanger 65a functioning as a radiator of a use-side refrigerant and heating a water medium, and the first use-side heat exchanger 41a functioning as an evaporator of the use-side refrigerant by radiating the heat-source-side refrigerant. A capacity of the heat-source-side compressor 21 is controlled so that a saturation temperature corresponding to a pressure of the heat-source-side refrigerant at a discharge of the heat-source-side compressor 21 is equal to a target temperature, and a capacity of the use-side compressor 62a is controlled so that a saturation temperature corresponding to a pressure of the use-side refrigerant at a discharge of the use-side compressor 62a is equal to a target temperature.

Description

  The present invention relates to a heat pump system, and more particularly to a heat pump system capable of heating an aqueous medium using a heat pump cycle.

  2. Description of the Related Art Conventionally, there is a heat pump water heater that can heat water using a heat pump cycle as disclosed in Patent Document 1 (Japanese Patent Laid-Open No. 60-164157). Such a heat pump water heater mainly has a compressor, a refrigerant-water heat exchanger, and a heat source side heat exchanger, and heats the water by the heat radiation of the refrigerant in the refrigerant-water heat exchanger. It is comprised so that the warm water produced may be supplied to a hot water tank.

  In the above conventional heat pump water heater, in order to supply hot hot water to the hot water tank, not only a refrigerant-water heat exchanger but also an auxiliary heater is used to heat water or increase the discharge pressure of the compressor. Therefore, it is necessary to perform the operation under such a condition that the operation efficiency is poor, which is not preferable.

  The subject of this invention is making it possible to obtain a high temperature aqueous medium in the heat pump system which can heat an aqueous medium using a heat pump cycle.

  The heat pump system according to the first aspect of the present invention includes a heat source side refrigerant circuit and a use side refrigerant circuit. The heat source side refrigerant circuit includes a variable capacity heat source side compressor that compresses the heat source side refrigerant, a first use side heat exchanger that can function as a heat source side refrigerant radiator, and a heat source side refrigerant radiator. And a heat source side heat exchanger capable of functioning as The usage-side refrigerant circuit includes a variable-capacity usage-side compressor that compresses the usage-side refrigerant, a refrigerant-water heat exchanger that functions as a radiator for the usage-side refrigerant and can heat the aqueous medium, and a heat source. A first usage-side heat exchanger capable of functioning as an evaporator of the usage-side refrigerant by heat radiation of the side-side refrigerant. The heat pump system has a capacity of the heat source side compressor such that the heat source side discharge saturation temperature, which is a saturation temperature corresponding to the pressure of the heat source side refrigerant in the discharge of the heat source side compressor, becomes a predetermined target heat source side discharge saturation temperature. And controlling the capacity of the utilization side compressor so that the utilization side discharge saturation temperature, which is the saturation temperature corresponding to the pressure of the utilization side refrigerant at the discharge of the utilization side compressor, becomes a predetermined target utilization side discharge saturation temperature. . Further, the target use side discharge saturation temperature is varied by a predetermined target aqueous medium outlet temperature which is a target value of the temperature of the aqueous medium at the outlet of the refrigerant-water heat exchanger. Further, the target heat source side discharge saturation temperature is varied depending on the target use side discharge saturation temperature or the target aqueous medium outlet temperature.

  In this heat pump system, in the first usage-side heat exchanger, the usage-side refrigerant circulating in the usage-side refrigerant circuit is heated by the heat radiation of the heat-source side refrigerant circulating in the heat-source-side refrigerant circuit. Since the circuit can obtain a refrigeration cycle having a higher temperature than the refrigeration cycle in the heat source side refrigerant circuit by using the heat obtained from the heat source side refrigerant, the circuit is heated by the heat radiation of the usage side refrigerant in the refrigerant-water heat exchanger. An aqueous medium can be obtained. At this time, in order to stably obtain a high-temperature aqueous medium, it is preferable to control so that the refrigeration cycle in the heat source side refrigerant circuit and the refrigeration cycle in the use side refrigerant circuit are both stable, but in this heat pump system, Both compressors of both refrigerant circuits are variable capacity type, and the saturation temperature corresponding to the refrigerant pressure at the discharge of each compressor (that is, the heat source side discharge saturation temperature and the use side discharge saturation temperature) is the refrigerant of each refrigeration cycle. Since the capacity control of each compressor is performed so that each discharge saturation temperature becomes the target discharge saturation temperature using the pressure as a representative value, the refrigeration cycle state in both refrigerant circuits can be stabilized. Thus, a high-temperature aqueous medium can be stably obtained.

  Further, in this heat pump system, since the target use-side discharge saturation temperature is appropriately set according to the target aqueous medium outlet temperature at the outlet of the refrigerant-water heat exchanger, a desired target aqueous medium outlet temperature is easily obtained, In addition, even when the target aqueous medium outlet temperature is changed, control with good responsiveness can be performed.

  Furthermore, in this heat pump system, since the target heat source side discharge saturation temperature is appropriately set according to the target use side discharge saturation temperature or the target aqueous medium outlet temperature, the heat pump system is set according to the state of the refrigeration cycle in the use side refrigerant circuit. The refrigeration cycle in the heat source side refrigerant circuit can be controlled so as to be in an appropriate state.

  A heat pump system according to a second aspect of the present invention is the heat pump system according to the first aspect of the present invention, wherein the utilization side refrigerant circuit is capable of varying the flow rate of the heat source side refrigerant flowing through the first utilization side heat exchanger. And a use side inlet / outlet pressure difference, which is a pressure difference between the pressure of the use side refrigerant at the discharge of the use side compressor and the pressure of the use side refrigerant at the suction of the use side compressor, is predetermined. When the pressure difference is less than or equal to the use side low load control pressure, control is performed to reduce the opening of the first use side flow rate control valve.

  As in the heat pump system according to the first aspect of the invention, the saturation temperature corresponding to the refrigerant pressure at the discharge of each compressor in both refrigerant circuits (that is, the heat source side discharge saturation temperature and the use side discharge saturation temperature) becomes the target temperature. Thus, in the configuration in which the capacity control of each compressor is performed, when supply of an aqueous medium with a wide temperature is required, the pressure of the use side refrigerant at the discharge of the use side compressor and the use side at the suction of the use side compressor The use side inlet / outlet pressure difference, which is the pressure difference from the refrigerant pressure, becomes very small, and the refrigeration cycle of the use side refrigerant circuit may not be controlled by the capacity control of the use side compressor alone.

  Therefore, in this heat pump system, the use side inlet / outlet pressure difference, which is the pressure difference between the pressure of the use side refrigerant at the discharge of the use side compressor and the pressure of the use side refrigerant at the suction of the use side compressor, is protected by the use side low differential pressure protection. When the pressure difference is less than or equal to the pressure difference, by performing control to reduce the opening of the first usage-side flow rate control valve that can vary the flow rate of the heat source-side refrigerant flowing through the first usage-side heat exchanger, Even when the inlet / outlet pressure difference is very small, there is a demand to supply an aqueous medium with a wide temperature range by suppressing the heat exchange capacity in the first usage side heat exchanger and increasing the usage side inlet / outlet pressure difference. It can correspond to.

  A heat pump system according to a third aspect of the present invention is the heat pump system according to the second aspect of the present invention, wherein the use side inlet / outlet pressure difference is larger than the use side low load control pressure difference at the outlet of the first use side heat exchanger. The opening degree control of the first use side flow rate control valve is performed so that the heat source side refrigerant subcooling degree, which is the degree of subcooling of the heat source side refrigerant, becomes a predetermined target heat source side refrigerant subcooling degree.

  In this heat pump system, when the use side inlet / outlet pressure difference is larger than the use side low load control pressure difference and the suppression of the heat exchange capacity in the first use side heat exchanger is not required, the heat source side refrigerant subcooling degree is Since the opening degree of the first usage side flow rate control valve is controlled so as to achieve the target heat source side refrigerant subcooling degree, the operation is performed under conditions suitable for the heat exchange capacity of the first usage side heat exchanger. Can do.

  The heat pump system according to a fourth aspect of the present invention is the heat pump system according to the third aspect of the present invention, wherein when the use side inlet / outlet pressure difference is equal to or less than the use side low load control pressure difference, the target heat source side refrigerant subcooling degree is increased.

  In this heat pump system, in the opening degree control of the first usage-side flow rate control valve that sets the heat source side refrigerant subcooling degree to the target heat source side refrigerant subcooling degree, the first usage is increased by increasing the target heat source side refrigerant subcooling degree. Since the heat exchange capacity of the side heat exchanger is suppressed, the heat source side refrigerant subcooling degree is set to the target heat source side refrigerant supercooling degree regardless of whether the user side inlet / outlet pressure difference is equal to or smaller than the user side low load control pressure difference. The opening degree control of the first usage-side flow rate control valve that makes the degree of cooling can be adopted.

  A heat pump system according to a fifth aspect of the present invention includes a heat source side refrigerant circuit and a use side refrigerant circuit. The heat source side refrigerant circuit includes a variable capacity heat source side compressor that compresses the heat source side refrigerant, a first use side heat exchanger that can function as a heat source side refrigerant radiator, and a heat source side refrigerant radiator. And a heat source side heat exchanger capable of functioning as The usage-side refrigerant circuit includes a variable-capacity usage-side compressor that compresses the usage-side refrigerant, a refrigerant-water heat exchanger that functions as a radiator for the usage-side refrigerant and can heat the aqueous medium, and a heat source. A first usage-side heat exchanger capable of functioning as an evaporator of the usage-side refrigerant by heat radiation of the side-side refrigerant. The heat pump system has a capacity of the heat source side compressor such that the heat source side discharge saturation temperature, which is a saturation temperature corresponding to the pressure of the heat source side refrigerant in the discharge of the heat source side compressor, becomes a predetermined target heat source side discharge saturation temperature. And controlling the capacity of the utilization side compressor so that the utilization side discharge saturation temperature, which is the saturation temperature corresponding to the pressure of the utilization side refrigerant at the discharge of the utilization side compressor, becomes a predetermined target utilization side discharge saturation temperature. . The heat source side refrigerant circuit includes a heat source side heat radiation operation state in which the heat source side heat exchanger functions as a heat source side refrigerant radiator, and a heat source side evaporation operation state in which the heat source side heat exchanger functions as an evaporator of the heat source side refrigerant. The utilization side refrigerant circuit further functions as a radiator of the utilization side refrigerant and uses the first utilization side heat exchanger on the utilization side. Use side heat radiation operation state to function as a refrigerant evaporator and use side evaporation to cause the refrigerant-water heat exchanger to function as a utilization side refrigerant evaporator and the first utilization side heat exchanger to function as a utilization side refrigerant radiator It further has a first usage side switching mechanism capable of switching between operating states. If it is determined that the heat source side heat exchanger needs to be defrosted, the heat source side heat exchanger functions as a heat source side refrigerant radiator by setting the heat source side switching mechanism to the heat source side heat radiation operation state. And causing the refrigerant-water heat exchanger to function as an evaporator of the usage-side refrigerant by setting the first usage-side switching mechanism to the usage-side evaporation operation state, and the first usage-side heat exchanger of the usage-side refrigerant. Perform defrosting operation to function as a radiator.

  In this heat pump system, in the first usage-side heat exchanger, the usage-side refrigerant circulating in the usage-side refrigerant circuit is heated by the heat radiation of the heat-source side refrigerant circulating in the heat-source-side refrigerant circuit. Since the circuit can obtain a refrigeration cycle having a higher temperature than the refrigeration cycle in the heat source side refrigerant circuit by using the heat obtained from the heat source side refrigerant, the circuit is heated by the heat radiation of the usage side refrigerant in the refrigerant-water heat exchanger. An aqueous medium can be obtained. At this time, in order to stably obtain a high-temperature aqueous medium, it is preferable to control so that the refrigeration cycle in the heat source side refrigerant circuit and the refrigeration cycle in the use side refrigerant circuit are both stable, but in this heat pump system, Both compressors of both refrigerant circuits are variable capacity type, and the saturation temperature corresponding to the refrigerant pressure at the discharge of each compressor (that is, the heat source side discharge saturation temperature and the use side discharge saturation temperature) is the refrigerant of each refrigeration cycle. Since the capacity control of each compressor is performed so that each discharge saturation temperature becomes the target discharge saturation temperature using the pressure as a representative value, the refrigeration cycle state in both refrigerant circuits can be stabilized. Thus, a high-temperature aqueous medium can be stably obtained.

  In this heat pump system, when the heat source side heat exchanger is defrosted, the heat source side heat exchanger is made to function as a heat source side refrigerant radiator by setting the heat source side switching mechanism to the heat source side heat radiation operation state. Instead, the refrigerant-water heat exchanger is caused to function as an evaporator of the use-side refrigerant by setting the first use-side switching mechanism to the use-side evaporation operation state, and the first use-side heat exchanger is dissipated from the use-side refrigerant. Therefore, the heat-source-side refrigerant that has been radiated and cooled in the heat-source-side heat exchanger is heated by the heat-radiation of the utilization-side refrigerant in the first usage-side heat exchanger, and the first usage-side heat exchange is performed. The use-side refrigerant radiated and cooled in the heat generator can be heated by evaporating in the refrigerant-water heat exchanger, and the heat source side heat exchanger can be defrosted reliably.

  Here, in this heat pump system, when the defrosting operation is performed, the heat source side switching mechanism is set to the heat source side heat radiation operation state, and the first usage side switching mechanism is switched to the usage side evaporation operation state, whereby each refrigerant circuit However, it is preferable to prevent the pressure equalization noise from becoming excessive. .

  Therefore, in this heat pump system, when performing the defrosting operation, after the heat source side switching mechanism is set to the heat source side heat radiation operation state, the first usage side switching mechanism is set to the usage side evaporating operation state. The refrigerant in the circuit is prevented from being equalized at the same time. Thereby, it is possible to prevent excessive pressure equalization when performing the defrosting operation.

  In the heat pump system according to the sixth aspect of the present invention, in the heat pump system according to the fifth aspect of the invention, when performing the defrosting operation, the use side compressor is stopped and the first use side switching mechanism is used on the use side evaporation. Put in operation.

  In this heat pump system, when the defrosting operation is performed, the use side compressor is stopped and the first use side switching mechanism is set to the use side evaporation operation state. The pressure noise can be prevented from becoming large.

  A heat pump system according to a seventh aspect is the heat pump system according to the sixth aspect, wherein the use side refrigerant circuit is capable of changing a flow rate of the use side refrigerant flowing through the refrigerant-water heat exchanger. In addition, when the defrosting operation is performed, the use-side compressor is stopped while the refrigerant-hydrothermal exchange-side flow rate control valve remains open.

  In this heat pump system, when performing the defrosting operation, the use-side compressor is stopped while the refrigerant-water heat exchange side flow rate control valve is open, so that the pressure equalization in the use-side refrigerant circuit can be quickly performed. Can be done.

  A heat pump system according to an eighth aspect of the present invention is the heat pump system according to any one of the first to seventh aspects of the present invention, wherein the heat source side compressor is started when the heat source side compressor and the utilization side compressor are stopped. After starting, start the compressor on the user side.

  In this heat pump system, when starting from a state where the heat source side compressor and the use side compressor are stopped, the use side compressor is started after starting the heat source side compressor. The heat exchange between the heat source side refrigerant and the use side refrigerant in the exchanger is less likely to be actively performed, whereby the pressure of the heat source side refrigerant at the discharge of the heat source side compressor quickly rises, and the heat source side compressor The heat source side inlet / outlet pressure difference, which is the difference between the pressure of the heat source side refrigerant at the discharge of the heat source and the pressure of the heat source side refrigerant at the suction of the heat source side compressor, is easily secured, and the heat source side refrigerant circuit is started quickly and stably. can do.

  A heat pump system according to a ninth aspect of the present invention is the heat pump system according to the eighth aspect of the present invention, wherein after the pressure of the heat source side refrigerant in the discharge of the heat source side compressor becomes equal to or higher than a predetermined heat source side starting discharge pressure, the use side compressor Start up.

  In this heat pump system, since the use side compressor is not started until the pressure of the heat source side refrigerant in the discharge of the heat source side compressor becomes equal to or higher than a predetermined heat source side start discharge pressure, in the discharge of the heat source side compressor It is possible to reliably prevent the use side compressor from being started while the pressure of the heat source side refrigerant is not increased.

  A heat pump system according to a tenth aspect of the invention is the heat pump system according to the eighth aspect of the invention, wherein the pressure difference between the pressure of the heat source side refrigerant at the discharge of the heat source side compressor and the pressure of the heat source side refrigerant at the suction of the heat source side compressor. The utilization side compressor is started after a certain heat source side inlet / outlet pressure difference becomes equal to or larger than a predetermined heat source side starting pressure difference.

  In this heat pump system, the heat source side inlet / outlet pressure difference, which is the pressure difference between the pressure of the heat source side refrigerant at the discharge of the heat source side compressor and the pressure of the heat source side refrigerant at the suction of the heat source side compressor, is equal to or greater than the heat source side starting pressure difference. Thus, since the use side compressor is not activated, it is possible to reliably prevent the use side compressor from being activated in a state where the heat source side inlet / outlet pressure difference is not secured.

  A heat pump system according to an eleventh aspect of the present invention is the heat pump system according to any one of the first to tenth aspects of the present invention, which has a capacity variable type circulation pump, and in the refrigerant-water heat exchanger, It further has an aqueous medium circuit in which an aqueous medium that exchanges heat is circulated. And this heat pump system starts a utilization side compressor in the state which stopped the circulating pump, or the state operated by small flow.

  In this heat pump system, when the user-side compressor is started, the user-side compressor is started in a state where the circulation pump is stopped or operated at a small flow rate, so that it is used in the refrigerant-water heat exchanger. The heat exchange between the refrigerant on the side and the aqueous medium is less likely to be actively performed, so that the pressure of the refrigerant on the usage side at the discharge of the usage side compressor rises quickly, and the usage side at the discharge of the usage side compressor The use side inlet / outlet pressure difference, which is the pressure difference between the refrigerant pressure and the use side refrigerant pressure in the suction of the use side compressor, is easily secured, and the use side refrigerant circuit can be started quickly and stably.

  A heat pump system according to a twelfth aspect of the present invention is the heat pump system according to the eleventh aspect of the present invention, wherein the aqueous medium circuit is disposed after the pressure of the utilization side refrigerant in the discharge of the utilization side compressor becomes equal to or higher than a predetermined utilization side activation discharge pressure. The capacity of the circulation pump is controlled so that the flow rate of the circulating aqueous medium is increased.

  In this heat pump system, since the flow rate of the aqueous medium circulating in the aqueous medium circuit is not increased until the pressure of the usage-side refrigerant at the discharge of the usage-side compressor becomes equal to or higher than the usage-side startup discharge pressure, It is possible to reliably prevent the capacity of the circulation pump from being controlled so that the flow rate of the aqueous medium circulating in the aqueous medium circuit is increased while the pressure of the use-side refrigerant at the discharge of the machine does not increase.

  A heat pump system according to a thirteenth invention is the heat pump system according to the eleventh invention, wherein the pressure difference between the pressure of the usage-side refrigerant at the discharge of the usage-side compressor and the pressure of the usage-side refrigerant at the suction of the usage-side compressor. The capacity control of the circulation pump is performed so that the flow rate of the aqueous medium circulating in the aqueous medium circuit is increased after a certain use-side inlet / outlet pressure difference becomes equal to or greater than a predetermined use-side activation pressure difference.

  In this heat pump system, the use side inlet / outlet pressure difference, which is the pressure difference between the pressure of the use side refrigerant at the discharge of the use side compressor and the pressure of the use side refrigerant at the suction of the use side compressor, becomes equal to or greater than the use side activation pressure difference. The flow rate of the aqueous medium circulating through the aqueous medium circuit is not increased so that the flow rate of the aqueous medium circulating through the aqueous medium circuit is increased without securing the use side inlet / outlet pressure difference. It is possible to reliably prevent the pump capacity from being controlled.

  A heat pump system according to a fourteenth invention includes a heat source side refrigerant circuit and a use side refrigerant circuit. The heat source side refrigerant circuit includes a variable capacity heat source side compressor that compresses the heat source side refrigerant, a first use side heat exchanger that can function as a heat source side refrigerant radiator, and a heat source side refrigerant radiator. And a heat source side heat exchanger capable of functioning as The usage-side refrigerant circuit includes a variable-capacity usage-side compressor that compresses the usage-side refrigerant, a refrigerant-water heat exchanger that functions as a radiator for the usage-side refrigerant and can heat the aqueous medium, and a heat source. A first usage-side heat exchanger capable of functioning as an evaporator of the usage-side refrigerant by heat radiation of the side-side refrigerant. The heat pump system has a capacity of the heat source side compressor such that the heat source side discharge saturation temperature, which is a saturation temperature corresponding to the pressure of the heat source side refrigerant in the discharge of the heat source side compressor, becomes a predetermined target heat source side discharge saturation temperature. And controlling the capacity of the utilization side compressor so that the utilization side discharge saturation temperature, which is the saturation temperature corresponding to the pressure of the utilization side refrigerant at the discharge of the utilization side compressor, becomes a predetermined target utilization side discharge saturation temperature. . The heat source side refrigerant circuit further includes a second usage side heat exchanger capable of heating the air medium by functioning as a heat source side refrigerant radiator. And when performing the operation which functions a 2nd utilization side heat exchanger as a heat radiator of a heat source side refrigerant | coolant, compared with the case where the operation which functions a 2nd utilization side heat exchanger as a heat radiator of a heat source side refrigerant | coolant is not performed. Increase the target heat source discharge saturation temperature.

  In this heat pump system, in the first usage-side heat exchanger, the usage-side refrigerant circulating in the usage-side refrigerant circuit is heated by the heat radiation of the heat-source side refrigerant circulating in the heat-source-side refrigerant circuit. Since the circuit can obtain a refrigeration cycle having a higher temperature than the refrigeration cycle in the heat source side refrigerant circuit by using the heat obtained from the heat source side refrigerant, the circuit is heated by the heat radiation of the usage side refrigerant in the refrigerant-water heat exchanger. An aqueous medium can be obtained. At this time, in order to stably obtain a high-temperature aqueous medium, it is preferable to control so that the refrigeration cycle in the heat source side refrigerant circuit and the refrigeration cycle in the use side refrigerant circuit are both stable, but in this heat pump system, Both compressors of both refrigerant circuits are variable capacity type, and the saturation temperature corresponding to the refrigerant pressure at the discharge of each compressor (that is, the heat source side discharge saturation temperature and the use side discharge saturation temperature) is the refrigerant of each refrigeration cycle. Since the capacity control of each compressor is performed so that each discharge saturation temperature becomes the target discharge saturation temperature using the pressure as a representative value, the refrigeration cycle state in both refrigerant circuits can be stabilized. Thus, a high-temperature aqueous medium can be stably obtained.

  And in this heat pump system, since the operation which heats an air medium by heat radiation of the heat source side refrigerant in the 2nd use side heat exchanger can be performed, the 1st use side heat exchanger and the use side refrigerant In addition to using the aqueous medium heated in the circuit for hot water supply, the air medium heated in the second utilization heat exchanger can be used for room heating.

  Moreover, in this heat pump system, when the operation for causing the second usage side heat exchanger to function as a heat radiator for the heat source side refrigerant is performed, the operation for causing the second usage side heat exchanger to function as a radiator for the heat source side refrigerant is performed. Since the target heat source side discharge saturation temperature is made larger than the case where it is not performed, in the case where the operation for causing the second usage side heat exchanger to function as a heat radiator of the heat source side refrigerant is not performed, in the heat source side refrigerant circuit When performing the operation in which the refrigeration cycle is performed at a pressure as low as possible to increase the operating efficiency in the heat source side refrigerant circuit and the second usage side heat exchanger functions as a heat source side refrigerant radiator, The heat source side refrigerant having a saturation temperature suitable for heating the air medium can be supplied to the side heat exchanger.

  A heat pump system according to a fifteenth aspect is the heat pump system according to any one of the first to thirteenth aspects, wherein the heat source side refrigerant circuit functions as an evaporator of the heat source side refrigerant to cool the air medium. A second usage-side heat exchanger capable of operating the first usage-side heat exchanger as a heat-source-side refrigerant radiator and evaporating the second usage-side heat exchanger as the heat-source-side refrigerant; It is possible to perform an operation that functions as a vessel.

  In this heat pump system, not only can the operation of heating the aqueous medium be performed by the first use side heat exchanger and the use side refrigerant circuit, but also the aqueous medium can be heated by the first use side heat exchanger and the use side refrigerant circuit. The cooling heat obtained by the heat source side refrigerant by performing the operation and heating the aqueous medium can be used for the operation of cooling the air medium by evaporation of the heat source side refrigerant in the second usage side heat exchanger. Therefore, for example, the aqueous medium heated by the first usage side heat exchanger and the usage side refrigerant circuit is used for hot water supply, and the air medium cooled in the second usage side heat exchanger is used for indoor cooling. Thus, the cooling heat obtained by the heat-source-side refrigerant by heating the aqueous medium can be used effectively, thereby saving energy.

  A heat pump system according to a sixteenth aspect of the present invention is the heat pump system according to any one of the first to fifteenth aspects, wherein there are a plurality of first use side heat exchangers, and the use side refrigerant circuit is each first use side heat. A plurality is provided to correspond to the exchanger.

  In this heat pump system, it is possible to cope with a plurality of places and applications that require heating of the aqueous medium.

  As described above, according to the present invention, the following effects can be obtained.

  In the first invention, a high-temperature aqueous medium can be stably obtained. In addition, a desired target aqueous medium outlet temperature can be easily obtained, and even when the target aqueous medium outlet temperature is changed, control with good responsiveness can be performed. Furthermore, it is possible to appropriately control the refrigeration cycle in the heat source side refrigerant circuit according to the state of the refrigeration cycle in the use side refrigerant circuit.

  In the second invention, even when the use side inlet / outlet pressure difference is very small, the heat exchange capability in the first use side heat exchanger is suppressed, and the use side inlet / outlet pressure difference is increased, so that the It is possible to meet the demand of supplying a temperature aqueous medium.

  In 3rd invention, it can drive | operate on the conditions suitable for the heat exchange capability of the 1st utilization side heat exchanger.

  In the fourth aspect of the invention, the first usage-side flow rate adjustment that sets the heat source side refrigerant subcooling degree to the target heat source side refrigerant subcooling degree regardless of whether the usage side inlet / outlet pressure difference is equal to or less than the usage side low load control pressure difference. Valve opening control can be employed.

  In the fifth invention, a high-temperature aqueous medium can be stably obtained. And the heat source side refrigerant radiated and cooled in the heat source side heat exchanger was heated in the first usage side heat exchanger by the radiation of the usage side refrigerant, and was radiated and cooled in the first usage side heat exchanger. The use-side refrigerant can be heated by evaporating in the refrigerant-water heat exchanger, whereby the heat source-side heat exchanger can be reliably defrosted. Moreover, it is possible to prevent excessive pressure equalization when performing the defrosting operation.

  In the sixth aspect of the invention, the pressure equalization sound in the use side refrigerant circuit can be prevented from becoming large.

  In the seventh invention, pressure equalization in the use-side refrigerant circuit can be performed quickly.

  In the eighth aspect of the invention, the heat source side refrigerant circuit can be started quickly and stably.

  In 9th invention, it can prevent reliably that a utilization side compressor is started in the state which the pressure of the heat source side refrigerant | coolant in discharge of a heat source side compressor does not rise.

  In the tenth invention, it is possible to reliably prevent the use side compressor from being started in a state in which the heat source side inlet / outlet pressure difference is not ensured.

  In the eleventh invention, the use-side refrigerant circuit can be started quickly and stably.

  In the twelfth aspect, the capacity control of the circulation pump is performed so that the flow rate of the aqueous medium circulating in the aqueous medium circuit is increased while the pressure of the usage-side refrigerant at the discharge of the usage-side compressor does not increase. It can be surely prevented.

  In the thirteenth aspect, it is possible to reliably prevent the capacity control of the circulation pump from being performed so that the flow rate of the aqueous medium circulating in the aqueous medium circuit is increased while the use side inlet / outlet pressure difference is not secured.

  In the fourteenth invention, a high-temperature aqueous medium can be stably obtained. And not only the aqueous medium heated in the 1st utilization side heat exchanger and the utilization side refrigerant circuit is used for hot water supply, but the air medium heated in the 2nd utilization heat exchanger is used for indoor heating. it can. Moreover, in the case where the operation for causing the second usage-side heat exchanger to function as a heat-source-side refrigerant radiator is not performed, the refrigeration cycle in the heat-source-side refrigerant circuit is performed at a pressure as low as possible, so that the heat-source-side refrigerant circuit In the case where the operation is performed such that the operation efficiency is increased and the second usage side heat exchanger functions as a heat source side refrigerant radiator, the second usage side heat exchanger has a saturation temperature suitable for heating the air medium. Can be supplied.

  In the fifteenth aspect of the invention, for example, the aqueous medium heated by the first usage-side heat exchanger and the usage-side refrigerant circuit is used for hot water supply, and the air medium cooled in the second usage-side heat exchanger is used for indoor cooling. The cooling heat obtained by the heat-source-side refrigerant by heating the aqueous medium can be effectively used, as in use, and thus energy saving can be achieved.

  In the sixteenth invention, it is possible to cope with a plurality of places and applications that require heating of the aqueous medium.

It is a schematic block diagram of the heat pump system concerning 1st Embodiment and the modification 1 of this invention. It is a flowchart which shows starting control of each circuit in 1st Embodiment, 2nd Embodiment, and 3rd Embodiment. It is a flowchart which shows the use side low load operation control in the modification 1 of 1st Embodiment, the modification 1 of 2nd Embodiment, and the modification 1 of 3rd Embodiment. It is a schematic block diagram of the heat pump system concerning the modification 2 of 1st Embodiment. It is a flowchart which shows the defrost operation in the modification 2 of 1st Embodiment, the modification 2 of 2nd Embodiment, and the modification 2 of 3rd Embodiment. It is a schematic block diagram of the heat pump system concerning the modification 3 of 1st Embodiment. It is a schematic block diagram of the heat pump system concerning 2nd Embodiment and the modification 1 of this invention. It is a schematic block diagram of the heat pump system concerning the modification 2 of 2nd Embodiment. It is a schematic block diagram of the heat pump system concerning the modification 3 of 2nd Embodiment. It is a schematic block diagram of the heat pump system concerning the modification 3 of 2nd Embodiment. It is a schematic block diagram of the heat pump system concerning the modification 3 of 2nd Embodiment. It is a schematic block diagram of the heat pump system concerning the modification 4 of 2nd Embodiment. It is a schematic block diagram of the heat pump system concerning 3rd Embodiment and the modification 1 of this invention. It is a schematic block diagram of the heat pump system concerning the modification 2 of 3rd Embodiment. It is a schematic block diagram of the heat pump system concerning the modification 3 of 3rd Embodiment. It is a schematic block diagram of the heat pump system concerning the modification 4 of 2nd Embodiment. It is a schematic block diagram of the heat pump system concerning the modification 4 of 2nd Embodiment. It is a schematic block diagram of the heat pump system concerning the modification 4 of 2nd Embodiment. It is a schematic block diagram of the heat pump system concerning the modification 5 of 2nd Embodiment.

  Hereinafter, an embodiment of a heat pump system according to the present invention will be described with reference to the drawings.

(First embodiment)
<Configuration>
-Overall-
FIG. 1 is a schematic configuration diagram of a heat pump system 1 according to the first embodiment of the present invention. The heat pump system 1 is an apparatus capable of performing an operation for heating an aqueous medium using a vapor compression heat pump cycle.

  The heat pump system 1 mainly includes a heat source unit 2, a first usage unit 4a, a liquid refrigerant communication tube 13, a gas refrigerant communication tube 14, a hot water storage unit 8a, a hot water heating unit 9a, and an aqueous medium communication tube 15a. The water source communication pipe 16a is provided, and the heat source unit 2 and the first usage unit 4a are connected via the refrigerant communication pipes 13 and 14, thereby constituting the heat source side refrigerant circuit 20 and the first usage. The unit 4a constitutes the use side refrigerant circuit 40a, and the first use unit 4a, the hot water storage unit 8a, and the hot water heating unit 9a are connected via the aqueous medium communication pipes 15a and 16a, thereby constituting the aqueous medium circuit 80a. doing. The heat source side refrigerant circuit 20 contains HFC-410A, which is a kind of HFC refrigerant, as a heat source refrigerant, and ester or ether refrigerating machine oil that is compatible with the HFC refrigerant is a heat source. It is enclosed for lubrication of the side compressor 22 (described later). Further, HFC-134a, which is a kind of HFC refrigerant, is sealed in the use side refrigerant circuit 40a as a use side refrigerant, and ester or ether type refrigerating machine oil having compatibility with the HFC refrigerant. Is enclosed for lubrication of the use side compressor 62a. In addition, as a use side refrigerant | coolant, from a viewpoint that the refrigerant | coolant advantageous to a high temperature refrigerating cycle is used, the pressure corresponding to saturation gas temperature 65 degreeC is 2.8 Mpa or less at the maximum at a gauge pressure, Preferably, it is 2.0 Mpa. The following refrigerants are preferably used. HFC-134a is a kind of refrigerant having such saturation pressure characteristics. Further, water as an aqueous medium circulates in the aqueous medium circuit 80a.

-Heat source unit-
The heat source unit 2 is installed outdoors and is connected to the utilization unit 4a via the refrigerant communication tubes 13 and 14, and constitutes a part of the heat source side refrigerant circuit 20.

  The heat source unit 2 mainly includes a heat source side compressor 21, an oil separation mechanism 22, a heat source side switching mechanism 23, a heat source side heat exchanger 24, a heat source side expansion mechanism 25, a suction return pipe 26, and a supercooling. A heat source side accumulator 28, a liquid side closing valve 29, and a gas side closing valve 30.

  The heat source side compressor 21 is a mechanism that compresses the heat source side refrigerant. Here, a rotary type or scroll type volumetric compression element (not shown) housed in a casing (not shown) is used. Similarly, a hermetic compressor driven by a heat source side compressor motor 21a accommodated in the casing is employed. A high-pressure space (not shown) filled with the heat-source-side refrigerant after being compressed by the compression element is formed in the casing of the heat-source-side compressor 21, and refrigerating machine oil is stored in the high-pressure space. ing. The heat source side compressor motor 21a can change the rotation speed (that is, the operating frequency) by an inverter device (not shown), thereby enabling capacity control of the heat source side compressor 21.

  The oil separation mechanism 22 is a mechanism for separating the refrigeration oil contained in the heat source side refrigerant discharged from the heat source side compressor 21 and returning it to the suction of the heat source side compressor. It has an oil separator 22a provided in the heat source side discharge pipe 21b, and an oil return pipe 22b connecting the oil separator 22a and the heat source side suction pipe 21c of the heat source side compressor 21. The oil separator 22a is a device that separates refrigeration oil contained in the heat source side refrigerant discharged from the heat source side compressor 21. The oil return pipe 22 b has a capillary tube, and is a refrigerant pipe that returns the refrigeration oil separated from the heat source side refrigerant in the oil separator 22 a to the heat source side suction pipe 21 c of the heat source side compressor 21.

  The heat source side switching mechanism 23 is a heat source side heat radiation operation state in which the heat source side heat exchanger 24 functions as a heat source side refrigerant radiator and a heat source side evaporation operation state in which the heat source side heat exchanger 24 functions as an evaporator of the heat source side refrigerant. A heat source side discharge pipe 21b, a heat source side suction pipe 21c, a first heat source side gas refrigerant pipe 23a connected to the gas side of the heat source side heat exchanger 24, and a gas The second heat source side gas refrigerant pipe 23 b connected to the side closing valve 30 is connected. The heat source side switching mechanism 23 communicates the heat source side discharge pipe 21b and the first heat source side gas refrigerant pipe 23a, and communicates the second heat source side gas refrigerant pipe 23b and the heat source side suction pipe 21c (heat source side heat dissipation). 1) (refer to the solid line of the heat source side switching mechanism 23 in FIG. 1), the heat source side discharge pipe 21b and the second heat source side gas refrigerant pipe 23b are communicated, and the first heat source side gas refrigerant pipe 23a Switching to communicate with the heat source side suction pipe 21c (corresponding to the heat source side evaporation operation state, see the broken line of the heat source side switching mechanism 23 in FIG. 1) can be performed. The heat source side switching mechanism 23 is not limited to the four-way switching valve, and has a function of switching the flow direction of the heat source side refrigerant as described above, for example, by combining a plurality of electromagnetic valves. It may be configured.

  The heat source side heat exchanger 24 is a heat exchanger that functions as a heat source side refrigerant radiator or an evaporator by exchanging heat between the heat source side refrigerant and outdoor air, and a heat source side liquid refrigerant tube 24a on the liquid side thereof. Are connected, and the first heat source side gas refrigerant pipe 23a is connected to the gas side thereof. The outdoor air that exchanges heat with the heat source side refrigerant in the heat source side heat exchanger 24 is supplied by the heat source side fan 32 driven by the heat source side fan motor 32a.

  The heat source side expansion valve 25 is an electric expansion valve that depressurizes the heat source side refrigerant flowing through the heat source side heat exchanger 24, and is provided in the heat source side liquid refrigerant pipe 24a.

  The suction return pipe 26 is a refrigerant pipe that branches a part of the heat source side refrigerant flowing through the heat source side liquid refrigerant pipe 24a and returns it to the suction of the heat source side compressor 21, and here, one end thereof is the heat source side liquid refrigerant pipe 24a. The other end is connected to the heat source side suction pipe 21c. The suction return pipe 26 is provided with a suction return expansion valve 26a whose opening degree can be controlled. The suction return expansion valve 26a is an electric expansion valve.

  The subcooler 27 heats the heat source side refrigerant flowing through the heat source side liquid refrigerant pipe 24a and the heat source side refrigerant flowing through the suction return pipe 26 (more specifically, the refrigerant after being decompressed by the suction return expansion valve 26a). It is a heat exchanger that performs exchange.

  The heat source side accumulator 28 is provided in the heat source side suction pipe 21c, and temporarily accumulates the heat source side refrigerant circulating in the heat source side refrigerant circuit 20 before being sucked into the heat source side compressor 21 from the heat source side suction pipe 21c. It is a container for.

  The liquid side closing valve 29 is a valve provided at a connection portion between the heat source side liquid refrigerant pipe 24 a and the liquid refrigerant communication pipe 13. The gas side shut-off valve 30 is a valve provided at a connection portion between the second heat source side gas refrigerant pipe 23 b and the gas refrigerant communication pipe 14.

  The heat source unit 2 is provided with various sensors. Specifically, the heat source unit 2 includes a heat source side suction pressure sensor 33 that detects a heat source side suction pressure Ps 1 that is a pressure of the heat source side refrigerant in the suction of the heat source side compressor 21, and a discharge in the heat source side compressor 21. The heat source side discharge pressure sensor 34 that detects the heat source side discharge pressure Pd1 that is the pressure of the heat source side refrigerant, and the heat source side heat exchanger temperature Thx that is the temperature of the heat source side refrigerant on the liquid side of the heat source side heat exchanger 24 are detected. A heat source side heat exchange temperature sensor 35 and an outside air temperature sensor 36 for detecting the outside air temperature To are provided.

−Liquid refrigerant connection tube−
The liquid refrigerant communication tube 13 is connected to the heat source side liquid refrigerant tube 24a via the liquid side closing valve 29, and the heat source side switching mechanism 23 functions as a heat source side refrigerant radiator in the heat source side heat radiation operation state. The heat source side refrigerant can be led out of the heat source unit 2 from the outlet of the heat exchanger 24, and the heat source side switching mechanism 23 functions as an evaporator of the heat source side refrigerant from the outside of the heat source unit 2 in the heat source side evaporation operation state. This is a refrigerant pipe capable of introducing the heat source side refrigerant into the inlet of the heat source side heat exchanger 24.

-Gas refrigerant communication tube-
The gas refrigerant communication pipe 14 is connected to the second heat source side gas refrigerant pipe 23b through the gas side shut-off valve 30, and the heat source side switching mechanism 23 from outside the heat source unit 2 in the heat source side heat radiation operation state. It is possible to introduce the heat source side refrigerant into the suction of the heat source 21, and the heat source side switching mechanism 23 may lead the heat source side refrigerant out of the heat source unit 2 from the discharge of the heat source side compressor 21 in the heat source side evaporation operation state. Possible refrigerant pipe.

-First use unit-
The first usage unit 4 a is installed indoors and connected to the heat source unit 2 via the refrigerant communication tubes 13 and 14 and constitutes a part of the heat source side refrigerant circuit 20. Moreover, the 1st utilization unit 4a comprises the utilization side refrigerant circuit 40a. Furthermore, the 1st utilization unit 4a is connected to the hot water storage unit 8a and the warm water heating unit 9a via the aqueous medium communication pipes 15a and 16a, and comprises a part of aqueous medium circuit 80a.

  The first usage unit 4a mainly includes a first usage-side heat exchanger 41a, a first usage-side flow rate adjustment valve 42a, a usage-side compressor 62a, a refrigerant-water heat exchanger 65a, and a refrigerant-hydrothermal exchange. It has a side flow rate adjustment valve 66a, a use side accumulator 67a, and a circulation pump 43a.

  The first usage-side heat exchanger 41a is a heat exchanger that functions as a radiator of the heat source-side refrigerant by exchanging heat between the heat source-side refrigerant and the usage-side refrigerant, and is a liquid in a flow path through which the heat source-side refrigerant flows. A first usage side liquid refrigerant pipe 45a is connected to the side, and a first usage side gas refrigerant pipe 54a is connected to the gas side of the flow path through which the heat source side refrigerant flows, and the usage side refrigerant. A cascade side liquid refrigerant pipe 68a is connected to the liquid side of the flow path through which the refrigerant flows, and a second cascade side gas refrigerant pipe 69a is connected to the gas side of the flow path through which the use side refrigerant flows. The liquid refrigerant communication pipe 13 is connected to the first usage side liquid refrigerant pipe 45a, the gas refrigerant communication pipe 14 is connected to the first usage side gas refrigerant pipe 54a, and the cascade side liquid refrigerant pipe 68a. A refrigerant-water heat exchanger 65a is connected to the second cascade side gas refrigerant pipe 69a, and a use side compressor 62a is connected to the second cascade side gas refrigerant pipe 69a.

  The first usage-side flow rate adjustment valve 42a is an electric expansion valve capable of changing the flow rate of the heat source-side refrigerant flowing through the first usage-side heat exchanger 41a by performing opening degree control. It is provided in the refrigerant pipe 45a.

  The use side compressor 62a is a mechanism for compressing the use side refrigerant, and here, a rotary type or scroll type volumetric compression element (not shown) housed in a casing (not shown), Similarly, a hermetic compressor driven by a use side compressor motor 63a accommodated in the casing is employed. A high-pressure space (not shown) filled with the heat-source-side refrigerant after being compressed by the compression element is formed in the casing of the use-side compressor 62a, and refrigeration oil is stored in the high-pressure space. ing. The use-side compressor motor 63a can change the rotation speed (that is, the operating frequency) by an inverter device (not shown), thereby enabling capacity control of the use-side compressor 62a. Further, a cascade side discharge pipe 70a is connected to the discharge of the use side compressor 62a, and a cascade side intake pipe 71a is connected to the intake of the use side compressor 62a. The cascade side suction pipe 71a is connected to the second cascade side gas refrigerant pipe 69a.

  The refrigerant-water heat exchanger 65a is a heat exchanger that functions as a radiator for the usage-side refrigerant by exchanging heat between the usage-side refrigerant and the aqueous medium, and is disposed on the liquid side of the flow path through which the usage-side refrigerant flows. The cascade side liquid refrigerant pipe 68a is connected to the gas side of the flow path through which the use side refrigerant flows, and the first cascade side gas refrigerant pipe 72a is connected to the flow path through which the aqueous medium flows. A first usage-side water inlet pipe 47a is connected to the inlet side, and a first usage-side water outlet pipe 48a is connected to the outlet side of the flow path through which the aqueous medium flows. The first cascade side gas refrigerant pipe 72a is connected to the cascade side discharge pipe 70a, the aqueous medium communication pipe 15a is connected to the first use side water inlet pipe 47a, and the first use side water outlet pipe is connected. The aqueous medium communication pipe 16a is connected to 48a.

  The refrigerant-water heat exchange side flow rate adjustment valve 66a is an electric expansion valve capable of varying the flow rate of the use side refrigerant flowing through the refrigerant-water heat exchanger 65a by controlling the opening, and the cascade side liquid refrigerant. It is provided in the pipe 68a.

  The usage-side accumulator 67a is provided in the cascade-side suction pipe 71a, and temporarily stores the usage-side refrigerant circulating in the usage-side refrigerant circuit 40a before being sucked from the cascade-side suction pipe 71a into the usage-side compressor 62a. It is a container for.

  Thus, the use side compressor 62a, the refrigerant-water heat exchanger 65a, the refrigerant-water heat exchange side flow rate adjustment valve 66a, and the first use side heat exchanger 41a connect the refrigerant pipes 71a, 70a, 72a, 68a, 69a. The use-side refrigerant circuit 40a is configured by being connected via the connection.

  The circulation pump 43a is a mechanism for boosting the aqueous medium. Here, a pump in which a centrifugal or positive displacement pump element (not shown) is driven by a circulation pump motor 44a is employed. The circulation pump 43a is provided in the 1st utilization side water outlet pipe 48a. The circulation pump motor 44a can vary the rotation speed (that is, the operating frequency) by an inverter device (not shown), thereby enabling capacity control of the circulation pump 43a.

  Accordingly, the first usage unit 4a causes the first usage-side heat exchanger 41a to radiate heat by causing the first usage-side heat exchanger 41a to function as a heat radiator for the heat-source-side refrigerant introduced from the gas refrigerant communication tube 14. The used heat source side refrigerant is led out to the liquid refrigerant communication pipe 13, and the use side refrigerant circulating in the use side refrigerant circuit 40a is heated by the heat radiation of the heat source side refrigerant in the first use side heat exchanger 41a, and this heated use side After the refrigerant is compressed in the use-side compressor 62a, it is possible to perform a hot water supply operation for heating the aqueous medium by radiating heat in the refrigerant-water heat exchanger 65a.

  The first usage unit 4a is provided with various sensors. Specifically, the first usage unit 4a includes a first usage-side heat exchange temperature sensor that detects the first usage-side refrigerant temperature Tsc1, which is the temperature of the heat-source-side refrigerant on the liquid side of the first usage-side heat exchanger 41a. 50a, a first refrigerant-water heat exchanger temperature sensor 73a that detects a cascade-side refrigerant temperature Tsc2 that is the temperature of the use-side refrigerant on the liquid side of the refrigerant-water heat exchanger 65a, and an inlet of the refrigerant-water heat exchanger 65a An aqueous medium outlet temperature sensor 51a that detects an aqueous medium inlet temperature Twr that is the temperature of the aqueous medium in the water medium, and an aqueous medium outlet that detects an aqueous medium outlet temperature Twl that is the temperature of the aqueous medium at the outlet of the refrigerant-water heat exchanger 65a A temperature sensor 52a, a use side suction pressure sensor 74a that detects a use side suction pressure Ps2 that is a pressure of the use side refrigerant in the suction of the use side compressor 62a, and a discharge of the use side compressor 62a A use-side discharge pressure sensor 75a that detects a use-side discharge pressure Pd2 that is the pressure of the use-side refrigerant and a use-side discharge that detects a use-side discharge temperature Td2 that is the temperature of the use-side refrigerant in the discharge of the use-side compressor 62a. A temperature sensor 76a is provided.

-Hot water storage unit-
The hot water storage unit 8a is installed indoors, is connected to the first usage unit 4a via the aqueous medium communication pipes 15a and 16a, and constitutes a part of the aqueous medium circuit 80a.

  The hot water storage unit 8a mainly has a hot water storage tank 81a and a heat exchange coil 82a.

  The hot water storage tank 81a is a container for storing water as an aqueous medium supplied for hot water supply, and a hot water supply pipe 83a for sending the aqueous medium heated to a faucet or a shower is connected to the upper part of the hot water storage tank 81a. A water supply pipe 84a for replenishing the aqueous medium consumed by the hot water supply pipe 83a is connected to the lower part thereof.

  The heat exchange coil 82a is provided in the hot water storage tank 81a, and heats the aqueous medium in the hot water storage tank 81a by performing heat exchange between the aqueous medium circulating in the aqueous medium circuit 80a and the aqueous medium in the hot water storage tank 81a. A water medium communication pipe 16a is connected to an inlet of the heat exchanger, and an aqueous medium communication pipe 15a is connected to an outlet of the heat exchanger.

  Thereby, the hot water storage unit 8a can heat the aqueous medium in the hot water storage tank 81a by the aqueous medium circulating in the aqueous medium circuit 80a heated in the first usage unit 4a and store it as hot water. Here, as the hot water storage unit 8a, a hot water storage unit of a type in which an aqueous medium heated by heat exchange with the aqueous medium heated in the first usage unit 4a is stored in a hot water storage tank is used. You may employ | adopt the type of hot water storage unit which accumulates the aqueous medium heated in the unit 4a in the hot water storage tank.

  The hot water storage unit 8a is provided with various sensors. Specifically, the hot water storage unit 8a is provided with a hot water storage temperature sensor 85a for detecting the hot water storage temperature Twh which is the temperature of the aqueous medium stored in the hot water storage tank 81a.

-Hot water heating unit-
The hot water heating unit 9a is installed indoors, is connected to the first usage unit 4a via the aqueous medium communication pipes 15a and 16a, and constitutes a part of the aqueous medium circuit 80a.

  The hot water heating unit 9a mainly has a heat exchange panel 91a, and constitutes a radiator, a floor heating panel, and the like.

  In the case of a radiator, the heat exchange panel 91a is provided near the wall of the room, and in the case of a floor heating panel, the heat exchange panel 91a is provided under the floor of the room, and the water medium radiator circulating in the water medium circuit 80a. The aqueous medium communication pipe 16a is connected to the inlet of the heat exchanger, and the aqueous medium communication pipe 15a is connected to the outlet of the heat exchanger.

-Aqueous medium connection pipe-
The aqueous medium communication pipe 15a is connected to the outlet of the heat exchange coil 82a of the hot water storage unit 8a and the outlet of the heat exchange panel 91a of the hot water heating unit 9a. The aqueous medium communication pipe 16a is connected to the inlet of the heat exchange coil 82a of the hot water storage unit 8a and the inlet of the heat exchange panel 91a of the hot water heating unit 9a. The aqueous medium communication pipe 16a is switched to supply the aqueous medium circulating in the aqueous medium circuit 80a to both the hot water storage unit 8a and the hot water heating unit 9a, or to either the hot water storage unit 8a or the hot water heating unit 9a. An aqueous medium side switching mechanism 161a that can be performed is provided. The aqueous medium side switching mechanism 161a is a three-way valve.

<Operation>
Next, the operation of the heat pump system 1 will be described.

  The operation mode of the heat pump system 1 includes a hot water supply operation mode in which the hot water supply operation of the first usage unit 4a (that is, the operation of the hot water storage unit 8a and / or the hot water heating unit 9a) is performed.

  Hereinafter, the operation in the hot water supply operation mode of the heat pump system 1 will be described.

-Hot water operation mode-
When the hot water supply operation of the first usage unit 4a is performed, in the heat source side refrigerant circuit 20, the heat source side switching mechanism 23 is in the heat source side evaporation operation state (the state indicated by the broken line of the heat source side switching mechanism 23 in FIG. 1). And the suction return expansion valve 26a is closed. In the aqueous medium circuit 80a, the aqueous medium switching mechanism 161a is switched to a state in which the aqueous medium is supplied to the hot water storage unit 8a and / or the hot water heating unit 9a.

  In the heat source side refrigerant circuit 20 in such a state, the low pressure heat source side refrigerant in the refrigeration cycle is sucked into the heat source side compressor 21 through the heat source side suction pipe 21c and compressed to a high pressure in the refrigeration cycle, and then the heat source side refrigerant circuit 20 is cooled. It is discharged to the discharge pipe 21b. The high pressure heat source side refrigerant discharged to the heat source side discharge pipe 21b is separated from the refrigerating machine oil in the oil separator 22a. The refrigerating machine oil separated from the heat source side refrigerant in the oil separator 22a is returned to the heat source side suction pipe 21c through the oil return pipe 22b. The high-pressure heat source side refrigerant from which the refrigerating machine oil is separated is sent from the heat source unit 2 to the gas refrigerant communication tube 14 through the heat source side switching mechanism 23, the second heat source side gas refrigerant tube 23b, and the gas side shut-off valve 30.

  The high-pressure heat-source-side refrigerant sent to the gas refrigerant communication tube 14 is sent to the first usage unit 4a. The high-pressure heat-source-side refrigerant sent to the first usage unit 4a is sent to the first usage-side heat exchanger 41a through the first usage-side gas refrigerant tube 54a. The high-pressure heat-source-side refrigerant sent to the first usage-side heat exchanger 41a exchanges heat with the low-pressure usage-side refrigerant in the refrigeration cycle circulating in the usage-side refrigerant circuit 40a in the first usage-side heat exchanger 41a. To dissipate heat. The high-pressure heat-source-side refrigerant radiated in the first usage-side heat exchanger 41a is sent from the first usage unit 4a to the liquid refrigerant communication tube 13 through the first usage-side flow rate adjustment valve 42a and the first usage-side liquid refrigerant tube 45a. It is done.

  The heat source side refrigerant sent to the liquid refrigerant communication tube 13 is sent to the heat source unit 2. The heat source side refrigerant sent to the heat source unit 2 is sent to the supercooler 27 through the liquid side shut-off valve 29. The heat source side refrigerant sent to the subcooler 27 is sent to the heat source side expansion valve 25 without performing heat exchange because the heat source side refrigerant does not flow through the suction return pipe 26. The heat source side refrigerant sent to the heat source side expansion valve 25 is depressurized by the heat source side expansion valve 25 to be in a low-pressure gas-liquid two-phase state, and sent to the heat source side heat exchanger 24 through the heat source side liquid refrigerant tube 24a. It is done. The low-pressure refrigerant sent to the heat source side heat exchanger 24 evaporates by exchanging heat with outdoor air supplied by the heat source side fan 32 in the heat source side heat exchanger 24. The low-pressure heat source side refrigerant evaporated in the heat source side heat exchanger 24 is sent to the heat source side accumulator 28 through the first heat source side gas refrigerant tube 23a and the heat source side switching mechanism 23. The low-pressure heat source side refrigerant sent to the heat source side accumulator 28 is again sucked into the heat source side compressor 21 through the heat source side suction pipe 21c.

  On the other hand, in the usage-side refrigerant circuit 40a, the low-pressure usage-side refrigerant in the refrigeration cycle circulating in the usage-side refrigerant circuit 40a is heated and evaporated by the heat radiation of the heat-source-side refrigerant in the first usage-side heat exchanger 41a. The low-pressure usage-side refrigerant evaporated in the first usage-side heat exchanger 41a is sent to the usage-side accumulator 67a through the second cascade-side gas refrigerant tube 69a. The low-pressure use-side refrigerant sent to the use-side accumulator 67a is sucked into the use-side compressor 62a through the cascade-side suction pipe 71a, compressed to a high pressure in the refrigeration cycle, and then discharged to the cascade-side discharge pipe 70a. . The high-pressure use-side refrigerant discharged to the cascade-side discharge pipe 70a is sent to the refrigerant-water heat exchanger 65a through the first cascade-side gas refrigerant pipe 72a. The high-pressure usage-side refrigerant sent to the refrigerant-water heat exchanger 65a radiates heat by exchanging heat with the aqueous medium circulating in the aqueous medium circuit 80a by the circulation pump 43a in the refrigerant-water heat exchanger 65a. The high-pressure use-side refrigerant that has radiated heat in the refrigerant-water heat exchanger 65a is decompressed in the refrigerant-water heat exchange side flow rate adjustment valve 66a to become a low-pressure gas-liquid two-phase state, and through the cascade-side liquid refrigerant pipe 68a. Again, it is sent to the 1st utilization side heat exchanger 41a.

  In the aqueous medium circuit 80a, the aqueous medium circulating in the aqueous medium circuit 80a is heated by the heat radiation of the use-side refrigerant in the refrigerant-water heat exchanger 65a. The aqueous medium heated in the refrigerant-water heat exchanger 65a is drawn into the circulation pump 43a through the first usage-side water outlet pipe 48a, and after being pressurized, is sent from the first usage unit 4a to the aqueous medium communication pipe 16a. It is done. The aqueous medium sent to the aqueous medium communication pipe 16a is sent to the hot water storage unit 8a and / or the hot water heating unit 9a through the aqueous medium side switching mechanism 161a. The aqueous medium sent to the hot water storage unit 8a exchanges heat with the aqueous medium in the hot water storage tank 81a in the heat exchange coil 82a to radiate heat, thereby heating the aqueous medium in the hot water storage tank 81a. The aqueous medium sent to the hot water heating unit 9a dissipates heat in the heat exchange panel 91a, thereby heating the indoor wall or the like or heating the indoor floor.

  Thus, the operation in the hot water supply operation mode for performing the hot water supply operation of the first usage unit 4a is performed.

-Discharge saturation temperature control of each refrigerant circuit and supercooling degree control of each heat exchanger outlet-
Next, the discharge saturation temperature control of the refrigerant circuits 20 and 40a and the supercooling degree control of the outlets of the heat exchangers 41a and 65a in the hot water supply operation described above will be described.

  In the heat pump system 1, as described above, in the first usage-side heat exchanger 41a, the usage-side refrigerant that circulates in the usage-side refrigerant circuit 40a is heated by the heat radiation of the heat-source-side refrigerant that circulates in the heat source-side refrigerant circuit 20. Since the use side refrigerant circuit 40a can obtain a refrigeration cycle having a temperature higher than that of the refrigeration cycle in the heat source side refrigerant circuit 20 using the heat obtained from the heat source side refrigerant, the refrigerant-water A high-temperature aqueous medium can be obtained by the heat radiation of the use-side refrigerant in the heat exchanger 65a. At this time, in order to stably obtain a high-temperature aqueous medium, it is preferable to control so that both the refrigeration cycle in the heat source side refrigerant circuit 20 and the refrigeration cycle in the use side refrigerant circuit 40a are stabilized.

  Therefore, in this heat pump system 1, the compressors 21, 62a of both refrigerant circuits 20, 40a are both of variable capacity type, and the saturation temperature corresponding to the refrigerant pressure at the discharge of each compressor 20, 62a (ie, heat source) Side discharge saturation temperature Tc1 and use side discharge saturation temperature Tc2) as representative values of the refrigerant pressure in each refrigeration cycle, so that each discharge saturation temperature Tc1, Tc2 becomes a predetermined target discharge saturation temperature Tc1s, Tc2s. The capacity of the compressors 21 and 62a is controlled.

  Here, the heat source side discharge saturation temperature Tc1 is a value obtained by converting the heat source side discharge pressure Pd1, which is the pressure of the heat source side refrigerant in the discharge of the heat source side compressor 21, into a saturation temperature corresponding to this pressure value. The discharge saturation temperature Tc2 is a value obtained by converting the use side discharge pressure Pd2 that is the pressure of the use side refrigerant in the discharge of the use side compressor 62a into a saturation temperature corresponding to this pressure value.

  In the heat source side refrigerant circuit 20, when the heat source side discharge saturation temperature Tc1 is lower than the target heat source side discharge saturation temperature Tc1s, the rotation speed (that is, the operating frequency) of the heat source side compressor 21 is increased. When the operation capacity of the heat source side compressor 21 is controlled to be large and the heat source side discharge saturation temperature Tc1 is higher than the target heat source side discharge saturation temperature Tc1s, the rotational speed of the heat source side compressor 21 (that is, the operation frequency). ) Is reduced so that the operation capacity of the heat source side compressor 21 is reduced. In the use side refrigerant circuit 40a, when the use side discharge saturation temperature Tc2 is lower than the target use side discharge saturation temperature Tc2s, the rotation speed (that is, the operating frequency) of the use side compressor 62a is increased. When the operation capacity of the use side compressor 62a is controlled to be large and the use side discharge saturation temperature Tc2 is higher than the target use side discharge saturation temperature Tc2s, the rotation speed (that is, the operation frequency) of the use side compressor 62a. ) Is reduced so that the operation capacity of the use side compressor 62a is reduced.

  Thereby, in the heat source side refrigerant circuit 20, the pressure of the heat source side refrigerant flowing in the first usage side refrigerant circuit 41a is stabilized, and in the usage side refrigerant circuit 40a, the pressure of the usage side refrigerant flowing in the refrigerant-water heat exchanger 65a is stabilized. Since the pressure is stabilized, the state of the refrigeration cycle in both refrigerant circuits 20 and 40a can be stabilized, and a high-temperature aqueous medium can be stably obtained.

  At this time, in order to obtain an aqueous medium having a desired temperature, it is preferable to appropriately set the target discharge saturation temperatures Tc1s and Tc2s.

  Therefore, in the heat pump system 1, first, for the use-side refrigerant circuit 41a, a predetermined target aqueous medium outlet temperature Twls that is a target value of the aqueous medium temperature at the outlet of the refrigerant-water heat exchanger 65a is set. The target use side discharge saturation temperature Tc2s is set as a value that can be varied by the target aqueous medium outlet temperature Twls. Here, for example, when the target aqueous medium outlet temperature Twls is set to 80 ° C., the target usage-side discharge saturation temperature Tc2s is set to 85 ° C., and the target aqueous medium outlet temperature Twls is set to 25 ° C. In such a case, the target use side discharge saturation temperature Tc2s becomes higher as the target aqueous medium outlet temperature Twls is set to a higher temperature, such as setting the target use side discharge saturation temperature Tc2s to 30 ° C. Thus, it is set as a function within the range of 30 ° C. to 85 ° C. so that the temperature is slightly higher than the target aqueous medium outlet temperature Twls. Thereby, since the target use side discharge saturation temperature Tc2s is appropriately set according to the target aqueous medium outlet temperature Twls, the desired target aqueous medium outlet temperature Tws is easily obtained, and the target aqueous medium outlet temperature Tws is changed. Even in such a case, control with good responsiveness can be performed.

  Further, for the heat source side refrigerant circuit 20, the target heat source side discharge saturation temperature Tc1s is set as a value that can be varied by the target use side discharge saturation temperature Tc2s or the target aqueous medium outlet temperature Tws. Here, for example, when the target use side discharge saturation temperature Tc2s or the target aqueous medium outlet temperature Tws is set to 75 ° C. or 80 ° C., the target heat source side discharge saturation temperature Tc1s is set to a temperature range of 35 ° C. to 40 ° C. When the target use side discharge saturation temperature Tc2s or the target aqueous medium outlet temperature Tws is set to 30 ° C. or 25 ° C., the target heat source side discharge saturation temperature Tc1s is set to 10 ° C. to 15 ° C. As the target use side discharge saturation temperature Tc2s or the target aqueous medium outlet temperature Tws is set to a higher temperature, the target heat source side discharge saturation temperature Tc1s also becomes a higher temperature range. And a function set within a range of 10 ° C. to 40 ° C. so that the temperature range is lower than the target use side discharge saturation temperature Tc2s or the target aqueous medium outlet temperature Tws. There. The target use side discharge saturation temperature Tc2s is preferably set as one temperature as described above for the purpose of accurately obtaining the target aqueous medium outlet temperature Tws, but the target heat source side discharge saturation temperature Tc1s. Is not required to be as strict as the target use-side discharge saturation temperature Tc2, but rather it is preferable to allow a certain temperature range, so it is preferable to set the temperature range as described above. Thereby, since the target heat source side discharge saturation temperature Tc1s is appropriately set according to the target use side discharge saturation temperature Tc2s or the target aqueous medium outlet temperature Tws, according to the state of the refrigeration cycle in the use side refrigerant circuit 40a. The refrigeration cycle in the heat source side refrigerant circuit 20 can be appropriately controlled.

  Further, in this heat pump system 1, the first use side flow rate adjustment valve 42a is used as a mechanism for performing main pressure reduction of the heat source side refrigerant flowing through the heat source side refrigerant circuit 20, and the main pressure reduction of the use side refrigerant flowing through the use side refrigerant circuit 40a. A refrigerant-water heat exchange side flow rate adjustment valve 66a is provided as a mechanism for performing the operation, and for the heat source side refrigerant circuit 20, the heat source side refrigerant excess that is the degree of subcooling of the heat source side refrigerant at the outlet of the first usage side heat exchanger 41a is provided. The opening degree of the first usage-side flow rate adjustment valve 42a is controlled so that the degree of cooling SC1 becomes the target heat source-side refrigerant subcooling degree SC1s, and for the usage-side refrigerant circuit 40a, the refrigerant-water heat exchanger 65a The degree of opening of the refrigerant-hydrothermal exchange side flow rate adjustment valve 66a is controlled so that the utilization side refrigerant supercooling degree SC2 that is the degree of supercooling of the utilization side refrigerant at the outlet of the refrigerant becomes the target utilization side refrigerant subcooling degree SC2s. It is way.

  Here, the heat source side refrigerant subcooling degree SC1 is a value obtained by subtracting the first usage side refrigerant temperature Tsc1 from the heat source side discharge saturation temperature Tc1, and the usage side refrigerant subcooling degree SC2 is cascaded from the usage side discharge saturation temperature Tc2. This is a value obtained by subtracting the side refrigerant temperature Tsc2.

  In the heat-source-side refrigerant circuit 20, when the heat-source-side refrigerant subcooling degree SC1 is smaller than the target heat-source-side refrigerant subcooling degree SC1s, the opening degree of the first usage-side flow rate adjustment valve 42a is reduced. When the flow rate of the heat source side refrigerant flowing through the 1 use side heat exchanger 41a is controlled to be small, and the heat source side refrigerant subcool degree SC1 is larger than the target heat source side refrigerant subcool degree SC1s, the first use side flow rate Control is performed so that the flow rate of the heat-source-side refrigerant flowing through the first usage-side heat exchanger 41a is increased by increasing the opening of the control valve 42a. In the use side refrigerant circuit 40a, when the use side refrigerant subcooling degree SC2 is smaller than the target use side refrigerant subcooling degree SC2s, the opening degree of the refrigerant-hydrothermal exchange side flow rate adjustment valve 66a is reduced. If the use-side refrigerant subcooling degree SC2 is greater than the target use-side refrigerant subcooling degree SC2s, the refrigerant-water heat is controlled. Control is performed so that the flow rate of the use-side refrigerant flowing through the refrigerant-water heat exchanger 65a is increased by increasing the opening degree of the exchange-side flow rate adjustment valve 66a. The target refrigerant subcooling degrees SC1s and SC2s are set in consideration of the design conditions of the heat exchange capability of the first usage-side heat exchanger 41a and the refrigerant-water heat exchanger 65a.

  Thereby, in the heat source side refrigerant circuit 20, the flow rate of the heat source side refrigerant flowing in the first usage side refrigerant circuit 41a is stabilized, and in the usage side refrigerant circuit 40a, the flow rate of the usage side refrigerant flowing in the refrigerant-water heat exchanger 65a is stabilized. Since the flow rate is stable, the operation can be performed under conditions suitable for the heat exchange capacity of the first usage-side heat exchanger 41a and the refrigerant-water heat exchanger 65a, and the state of the refrigeration cycle in both refrigerant circuits 20, 40a can be changed. Contributes to stabilization.

  Thus, in this heat pump system 1, the pressure and flow rate of the refrigerant in each refrigerant circuit 20, 40a is controlled by the discharge saturation temperature control of each refrigerant circuit 20, 40a and the supercooling degree control of each heat exchanger 41a, 65a outlet. As a result, the state of the refrigeration cycle in both refrigerant circuits 20 and 40a can be stabilized, and a high-temperature aqueous medium can be stably obtained.

-Flow control of aqueous medium circulating in aqueous medium circuit-
Next, the flow control of the aqueous medium circulating through the aqueous medium circuit 80a in the hot water supply operation described above will be described.

  In this heat pump system 1, the temperature of the aqueous medium at the outlet of the refrigerant-water heat exchanger 65a (ie, the aqueous medium outlet temperature Twl) and the temperature of the aqueous medium at the inlet of the refrigerant-water heat exchanger 65a (ie, the aqueous medium inlet). The capacity control of the circulation pump 43a is performed so that the aqueous medium inlet / outlet temperature difference ΔTw, which is a temperature difference from the temperature Twr) (that is, Twl−Twr) becomes the predetermined target aqueous medium inlet / outlet temperature difference ΔTws. More specifically, when the aqueous medium inlet / outlet temperature difference ΔTw is larger than the target aqueous medium inlet / outlet temperature difference ΔTws, it is determined that the flow rate of the aqueous medium circulating through the aqueous medium circuit 80a is small, and the circulation pump motor 44a. Is increased so that the operating capacity of the circulation pump 43a is increased. When the aqueous medium inlet / outlet temperature difference ΔTw is smaller than the target aqueous medium inlet / outlet temperature difference ΔTws, It is determined that the flow rate of the aqueous medium circulating through the medium circuit 80a is large, and the operation capacity of the circulation pump 43a is controlled to be small by reducing the rotation speed (that is, the operation frequency) of the circulation pump motor 44a. Thereby, the flow volume of the aqueous medium circulating through the aqueous medium circuit 80a is appropriately controlled. The target aqueous medium inlet / outlet temperature difference ΔTws is set in consideration of the design conditions of the heat exchange capacity of the refrigerant-water heat exchanger 65a.

-Start-up control of each circuit-
Next, activation control of each circuit 20, 40a, 80a when starting the above-described hot water supply operation will be described with reference to FIG.

  In this heat pump system 1, when starting the hot water supply operation by starting from the state where the heat source side compressor 21 and the use side compressor 62 a are stopped, first, the use side compressor 62 a is started after starting the heat source side compressor 21. Start up. More specifically, the heat source side compressor 21 is started (step S1), and after it is determined that a predetermined use side compressor start condition is satisfied (step S2), the use side compressor 62a is started. (Step S3).

  As a result, heat exchange between the heat-source-side refrigerant and the use-side refrigerant in the first use-side heat exchanger 41a is less likely to be performed positively, and this is the pressure of the heat-source-side refrigerant in the discharge of the heat source-side compressor 21. The heat source side discharge pressure Pd1 rises rapidly, and the heat source side inlet / outlet pressure difference which is the pressure difference between the heat source side discharge pressure Pd1 and the heat source side suction pressure Ps1 which is the pressure of the heat source side refrigerant in the suction of the heat source side compressor 21. ΔP1 is easily secured, and the heat source side refrigerant circuit 20 can be started quickly and stably.

  Here, the use side compressor starting condition is set in a state where the heat source side discharge pressure Pd1 is not increased or in a state where the heat source side inlet / outlet pressure difference ΔP1 is not ensured, that is, the heat source side refrigerant. This is to reliably prevent the use side compressor 62a from being started while the state of the refrigeration cycle in the circuit 20 is not stable. Here, as the compressor side start condition, the heat source side discharge pressure Pd1 is a predetermined heat source side. It is assumed that the starting discharge pressure Pdi1 or higher, or that the heat source side inlet / outlet pressure difference ΔP1 is equal to or higher than a predetermined heat source side starting pressure difference ΔPi1.

  Next, the use side compressor 62a is started. At this time, if the flow rate of the aqueous medium circulating in the aqueous medium circuit 80a is large, the temperature of the aqueous medium flowing through the refrigerant-water heat exchanger 65a is not easily increased. Immediately after the use-side compressor 62a is started, heat exchange between the use-side refrigerant and the aqueous medium in the refrigerant-water heat exchanger 65a is actively performed, whereby the use-side compressor 62a is used for discharging. The use side discharge pressure Pd2 that is the pressure of the side refrigerant is unlikely to rise quickly, and the pressure between the use side discharge pressure Pd2 and the use side suction pressure Ps2 that is the pressure of the use side refrigerant in the suction of the use side compressor 62a The use side inlet / outlet pressure difference ΔP <b> 2, which is the difference, is difficult to be secured, and the use side refrigerant circuit 40 a may not be able to be started quickly and stably.

  Therefore, in the heat pump system 1, the use side compressor 62a is started in a state where the circulation pump 43a is stopped or operated at a small flow rate (step S3). More specifically, the circulating pump 43a is stopped, or the rotational speed of the circulating pump motor 44a (that is, the operating frequency) is set to the minimum value so that the circulating pump 43a is operated at a small flow rate. The use side compressor 62a is started.

  As a result, heat exchange between the use-side refrigerant and the aqueous medium in the refrigerant-water heat exchanger 65a is less likely to be performed actively, and the use-side discharge pressure Pd2 is likely to rise quickly, and the use-side inlet / outlet pressure difference Since ΔP2 is easily secured, the use-side refrigerant circuit 40a can be started quickly and stably.

  Next, the capacity of the circulation pump 43a is controlled so that the flow rate of the aqueous medium flowing through the aqueous medium circuit 80a is increased (step S5). At this time, until it is determined that the predetermined increase condition of the circulation pump flow rate is satisfied ( In step S4), the capacity of the circulation pump 43a is not controlled so that the flow rate of the aqueous medium circulating through the aqueous medium circuit 80a is increased.

  Here, the circulation pump flow rate increasing condition is set in a state where the use side discharge pressure Pd2 is not increased or in a state where the use side inlet / outlet pressure difference ΔP2 is not secured, that is, in the use side refrigerant circuit 40a. The capacity control of the circulation pump 43a is performed so that the flow rate of the aqueous medium flowing through the aqueous medium circuit 80a is increased while the state of the refrigeration cycle is not stable (here, the aqueous medium inlet / outlet temperature difference ΔTw is the target aqueous medium inlet / outlet). This is to prevent the aqueous medium inlet / outlet temperature difference control for controlling the operation capacity of the circulation pump 43a so as to be the temperature difference ΔTws, and to prevent step S5) reliably. It is assumed that the discharge pressure Pd2 is equal to or higher than the predetermined use side activation discharge pressure Pdi2, or the use side inlet / outlet pressure difference ΔP2 is the predetermined use side start. It is set to be equal to or greater than the pressure difference ΔPi2.

<Features>
This heat pump system 1 has the following features.

-A-
In the heat pump system 1, in the first usage-side heat exchanger 41a, the usage-side refrigerant circulating in the usage-side refrigerant circuit 40a is heated by the heat radiation of the heat source-side refrigerant circulating in the heat source-side refrigerant circuit 20. Since the use-side refrigerant circuit 40a can obtain a refrigeration cycle having a temperature higher than that of the refrigeration cycle in the heat source-side refrigerant circuit 20 by using the heat obtained from the heat source-side refrigerant, the use-side refrigerant circuit 40a in the refrigerant-water heat exchanger 65a A high temperature aqueous medium can be obtained by the heat radiation of the use side refrigerant. At this time, in order to stably obtain a high-temperature aqueous medium, it is preferable to control so that both the refrigeration cycle in the heat source side refrigerant circuit 20 and the refrigeration cycle in the use side refrigerant circuit 40a are stable. 1, the compressors 21 and 62a of the refrigerant circuits 20 and 40a are both of variable capacity type, and the saturation temperature corresponding to the refrigerant pressure at the discharge of the compressors 21 and 62a (that is, the heat source side discharge saturation temperature Tc1). And the use side discharge saturation temperature Tc2) as the representative value of the refrigerant pressure in each refrigeration cycle, the capacities of the compressors 21 and 62a so that the discharge saturation temperatures Tc1 and Tc2 become the target discharge saturation temperatures Tc1s and Tc2s. Since the control is performed, the state of the refrigeration cycle in both refrigerant circuits 20, 40a can be stabilized. More, it is possible to stably obtain a high-temperature aqueous medium. Moreover, in the heat pump system 1, the first use side heat exchanger 41a is a heat exchanger that directly transfers heat by heat exchange between the heat source side refrigerant and the use side refrigerant, and the heat source side refrigerant circuit 20 Therefore, there is little heat loss when being transferred to the use side refrigerant circuit 40a, which contributes to obtaining a high temperature aqueous medium. Moreover, in this heat pump system 1, since the target use side discharge saturation temperature Tc2 is appropriately set according to the target aqueous medium outlet temperature Tws at the outlet of the refrigerant-water heat exchanger 65a, the desired target aqueous medium outlet temperature Tws is set. In addition, even when the target aqueous medium outlet temperature Tws is changed, it is possible to perform control with good responsiveness. Furthermore, in this heat pump system 1, since the target heat source side discharge saturation temperature Tc1s is appropriately set according to the target use side discharge saturation temperature Tc2s or the target aqueous medium outlet temperature Tws, the refrigeration in the use side refrigerant circuit 40a is performed. The refrigeration cycle in the heat source side refrigerant circuit 20 can be controlled so as to be in an appropriate state according to the state of the cycle.

-B-
In the heat pump system 1, when the heat source side compressor 21 and the use side compressor 62a are started from a stopped state, the use side compressor 62a is started after the heat source side compressor 21 is started. Heat exchange between the heat-source-side refrigerant and the user-side refrigerant in the first user-side heat exchanger 41a is less likely to be positively performed, and as a result, the pressure of the heat-source-side refrigerant at the discharge of the heat source-side compressor 21 increases quickly. Further, the heat source side inlet / outlet pressure difference ΔP1 which is the pressure difference between the heat source side discharge pressure Pd1 which is the pressure of the heat source side refrigerant in the discharge of the use side compressor 62a and the pressure of the heat source side refrigerant in the suction of the heat source side compressor 21 is The heat source side refrigerant circuit 20 can be started quickly and stably. Moreover, in the heat pump system 1, the use side compression is performed until the heat source side discharge pressure Pd1 becomes equal to or higher than the predetermined heat source side start discharge pressure Pdi1, or until the heat source side inlet / outlet pressure difference ΔP1 becomes equal to or higher than the heat source side start pressure difference ΔPdi1. Since the machine 62a is not started, the use side compressor 62a is started in a state where the heat source side discharge pressure Pd1 does not increase or in a state where the heat source side inlet / outlet pressure difference ΔPdi is not secured. It can be surely prevented.

-C-
In this heat pump system 1, when the use side compressor 62 a is started, the use side compressor 62 a is started in a state where the circulation pump 43 a is stopped or operated at a small flow rate. Heat exchange between the use-side refrigerant and the aqueous medium in the exchanger 65a is less likely to be actively performed, and thus the use-side discharge pressure Pd2 that is the pressure of the use-side refrigerant in the discharge of the use-side compressor 62a is quickly increased. In addition, the use-side inlet / outlet pressure difference ΔP2 that is the pressure difference between the use-side discharge pressure Pd2 and the use-side refrigerant pressure Pd2 that is the pressure of the use-side refrigerant in the suction of the use-side compressor 62a is easily secured. The refrigerant circuit 40a can be started quickly and stably. Moreover, in the heat pump system 1, the aqueous medium circuit 80a is used until the use side discharge pressure Pd2 becomes equal to or higher than the use side start discharge pressure Pdi2 or until the use side inlet / outlet pressure difference ΔP2 becomes equal to or higher than the use side start pressure difference ΔPdi2. Since the flow rate of the circulating aqueous medium is not increased, the aqueous medium circuit 80a is circulated while the usage-side discharge pressure Pd2 is not increased or the usage-side inlet / outlet pressure difference ΔPd2 is not secured. It is possible to reliably prevent the capacity control of the circulation pump 43a from being performed so that the flow rate of the aqueous medium to be increased.

(1) Modification 1
A saturation temperature corresponding to the refrigerant pressure in the discharge of the compressors 21 and 62a of both refrigerant circuits 20 and 40a as in the heat pump system 1 (see FIG. 1) (that is, the heat source side discharge saturation temperature Tc1 and the use side) In the configuration in which the capacity control of the compressors 21 and 62a is controlled so that the discharge saturation temperature Tc2) becomes the target temperatures Tc1s and Tc2s, when supply of a wide temperature aqueous medium is required (for example, the outside air temperature To is relatively low When the supply of an aqueous medium having a low temperature such as 25 ° C. is required as the target aqueous medium outlet temperature Twls in spite of the high temperature condition), the pressure of the utilization side refrigerant at the discharge of the utilization side compressor 62a The use side inlet / outlet pressure which is the pressure difference between the use side discharge pressure Pd2 and the use side refrigerant pressure in the use side compressor 62a. Since ΔP2 becomes very small and low-load operation is required for the use-side refrigerant circuit 40a, there is a risk that the refrigeration cycle of the use-side refrigerant circuit 40a cannot be controlled only by the capacity control of the use-side compressor 62a. There is. In addition, the decrease in the use side inlet / outlet pressure difference ΔP2 causes poor circulation of the refrigerating machine oil in the use side compressor 62a and causes insufficient lubrication.

  Therefore, in this heat pump system 1, as shown in FIG. 3, similarly to the above-described heat pump system 1 (see FIG. 1), while controlling the discharge saturation temperature of each refrigerant circuit 20, 40 a, the use side inlet / outlet pressure difference When ΔP2 becomes equal to or less than a predetermined usage-side low-load protection pressure difference ΔP2s (step S11), the first usage side capable of varying the flow rate of the heat source side refrigerant flowing through the first usage-side heat exchanger 41a. User-side low-load operation control, which is control for reducing the opening degree of the flow control valve 42a, is performed (step S11). The use side low load protection pressure difference ΔP2s is set in consideration of the design conditions of the heat exchange capacity of the first use side heat exchanger 41a, the design conditions of the lubrication structure of the use side compressor 62a, and the like.

  Thereby, even when the use side inlet / outlet pressure difference ΔP2 is very small, the flow rate of the heat source side refrigerant flowing into the first use side heat exchanger 41a is reduced, and the heat in the first use side heat exchanger 41a is reduced. The use side refrigerant circuit 40a can be easily operated even under a low load condition by suppressing the exchange capacity so that the use side inlet / outlet pressure difference ΔP2 is increased. be able to.

  Here, similarly to the above-described heat pump system 1 (see FIG. 1), when the supercooling degree control at the outlet of the first usage-side heat exchanger 41a is adopted as the control of the first usage-side flow rate adjustment valve 41a. When the use side inlet / outlet pressure difference ΔP2 is larger than the use side low load protection pressure difference ΔP2s (step S11), the target heat source side refrigerant subcooling in the supercooling degree control at the outlet of the first use side heat exchanger 41a is performed. By maintaining the value of degree SC1s, the control is not performed to reduce the opening degree of the first usage-side flow rate adjustment valve 42a, and the operation is performed under conditions suitable for the heat exchange capability of the first usage-side heat exchanger 41a. It can be performed. When the use side inlet / outlet pressure difference ΔP2 becomes equal to or less than the use side low load protection pressure difference ΔP2s (step S11), the target heat source side refrigerant subcooling in the supercooling degree control at the outlet of the first use side heat exchanger 41a is performed. Control for reducing the opening degree of the first usage-side flow rate adjusting valve 42a by setting the value SC1s to a value larger than the value when the usage-side inlet / outlet pressure difference ΔP2 is larger than the usage-side low-load protection pressure difference ΔP2s. Thus, the heat exchange capacity in the first use side heat exchanger 41a can be suppressed and the use side refrigerant circuit 40a can be operated under a low load condition, and the use side inlet / outlet pressure difference ΔP2 is controlled by the use side low load control. Regardless of whether or not the pressure difference is ΔP2s or less, the opening degree control of the first usage-side flow rate adjustment valve 42a is adopted to set the heat source side refrigerant subcooling degree SC1 to the target heat source side refrigerant subcooling degree SC1s. Rukoto can.

(2) Modification 2
In the above-described heat pump system 1 (see FIG. 1), as shown in FIG. 4, the refrigerant-water heat exchanger 65a functions as a radiator for the use-side refrigerant and the first use-side heat exchanger 41a serves as the use-side refrigerant. Use side heat radiation operating state to function as an evaporator of the use side and the use side to cause the refrigerant-water heat exchanger 65a to function as an evaporator of the use side refrigerant and to function the first use side heat exchanger 41a as a radiator of the use side refrigerant A first use side switching mechanism 64a capable of switching between the evaporation operation states may be further provided in the use side refrigerant circuit 40a.

  Here, the first use side switching mechanism 64a is a four-way switching valve, and includes a cascade side discharge pipe 70a, a cascade side suction pipe 71a, a first cascade side gas refrigerant pipe 72a, and a second cascade side gas refrigerant pipe. 69a. The first use side switching mechanism 64a communicates the cascade side discharge pipe 70a and the first cascade side gas refrigerant pipe 72a, and communicates (uses) the second cascade side gas refrigerant pipe 69a and the cascade side suction pipe 71a. Corresponding to the side heat radiation operation state (see the solid line of the first use side switching mechanism 64a in FIG. 17), the cascade side discharge pipe 70a and the second cascade side gas refrigerant pipe 69a are communicated, and the first cascade side gas It is possible to perform switching by connecting the refrigerant pipe 72a and the cascade side suction pipe 71a (corresponding to the use side evaporation operation state, see the broken line of the first use side switching mechanism 64a in FIG. 4). The first usage-side switching mechanism 64a is not limited to the four-way switching valve, and has a function of switching the direction of the usage-side refrigerant flow as described above, for example, by combining a plurality of electromagnetic valves. It may be configured as described above.

  In the heat pump system 1 having such a configuration, when it is determined by the operation in the hot water supply operation mode that the heat source side heat exchanger 24 needs to be defrosted, the heat source side switching mechanism 23 is in the heat source side heat radiation operation state. By making the heat source side heat exchanger 24 function as a heat radiator for the heat source side refrigerant, the refrigerant-water heat exchanger 65a is used on the usage side refrigerant by setting the first usage side switching mechanism 64a to the usage side evaporation operation state. It is possible to perform a defrosting operation in which the first usage-side heat exchanger 41a functions as a usage-side refrigerant radiator.

  Hereinafter, the operation in the defrosting operation will be described with reference to FIG.

  First, it is determined whether or not a predetermined defrosting operation start condition is satisfied (that is, whether or not the heat source side heat exchanger 24 needs to be defrosted) (step S21). Here, whether or not the defrosting operation start condition is satisfied depends on whether or not the defrosting time interval Δtdf (that is, the accumulated operation time from the end of the previous defrosting operation) has reached a predetermined defrosting time interval set value Δtdfs. judge.

  And when it determines with satisfy | filling the defrost operation start conditions, the following defrost operations are started (step S22).

  When starting the defrosting operation, in the heat source side refrigerant circuit 20, the heat source side switching mechanism 23 is switched to the heat source side heat dissipation operation state (the state indicated by the solid line of the heat source side switching mechanism 23 in FIG. 4). In the usage-side refrigerant circuit 40a, the first usage-side switching mechanism 64a is switched to the usage-side evaporation operation state (the state indicated by the broken line of the first usage-side switching mechanism 64a in FIG. 4), and the suction return expansion valve 26a is It becomes a closed state.

  When the heat source side switching mechanism 23 is set to the heat source side heat radiation operation state and the first usage side switching mechanism 64a is switched to the usage side evaporation operation state, the refrigerant in each refrigerant circuit 20, 40a Is generated, and a noise (that is, a pressure equalization sound) at the time of pressure equalization of the refrigerant in each of the refrigerant circuits 20 and 40a is generated. However, it is possible to prevent such pressure equalization sound from becoming excessive. preferable.

  Therefore, in the heat pump system 1, when the defrosting operation is started, the heat source side switching mechanism 23 is set to the heat source side heat radiation operation state, and then the first usage side switching mechanism 64a is set to the usage side evaporation operation state. The refrigerant in both refrigerant circuits 20 and 40a is prevented from being equalized simultaneously. Thereby, it is possible to prevent excessive pressure equalization when performing the defrosting operation.

  In the heat pump system 1, when the first usage-side switching mechanism 64a is set to the usage-side evaporation operation state, the usage-side compressor 62a is stopped and the first usage-side switching mechanism 64a is operated to the usage-side evaporation operation. Since it is made into a state, it can prevent that the equalization sound in the utilization side refrigerant circuit 40a becomes large.

  Furthermore, in this heat pump system 1, when the use side compressor 62a is stopped, the refrigerant-water heat exchange side flow rate adjustment valve 66a remains open (more specifically, fully open). Since the use side compressor 62a is stopped, the pressure equalization in the use side refrigerant circuit 40a can be performed quickly.

  In the heat source side refrigerant circuit 20 in such a state, the low pressure heat source side refrigerant in the refrigeration cycle is sucked into the heat source side compressor 21 through the heat source side suction pipe 21c and compressed to a high pressure in the refrigeration cycle, and then the heat source side refrigerant circuit 20 is cooled. It is discharged to the discharge pipe 21b. The high pressure heat source side refrigerant discharged to the heat source side discharge pipe 21b is separated from the refrigerating machine oil in the oil separator 22a. The refrigerating machine oil separated from the heat source side refrigerant in the oil separator 22a is returned to the heat source side suction pipe 21c through the oil return pipe 22b. The high-pressure heat-source-side refrigerant from which the refrigeration oil is separated is sent to the heat-source-side heat exchanger 24 through the heat-source-side switching mechanism 23 and the first heat-source-side gas refrigerant tube 23a. The high-pressure heat-source-side refrigerant sent to the heat-source-side heat exchanger 24 radiates heat by exchanging heat with ice attached to the heat-source-side heat exchanger 24 in the heat-source-side heat exchanger 24. The high-pressure heat-source-side refrigerant that has radiated heat in the heat-source-side heat exchanger is sent to the supercooler 27 through the heat source-side expansion valve 25. Since the heat source side refrigerant sent to the subcooler 27 does not flow through the suction return pipe 26, the heat source unit refrigerant passes through the heat source side liquid refrigerant tube 24a and the liquid side shut-off valve 29 without performing heat exchange. 2 to the liquid refrigerant communication tube 13.

  The heat-source-side refrigerant sent to the liquid refrigerant communication tube 13 is sent to the first usage unit 4a.

  The heat-source-side refrigerant sent to the first usage unit 4a is sent to the first usage-side flow rate adjustment valve 42a. The heat-source-side refrigerant sent to the first usage-side flow rate adjustment valve 42a is depressurized in the first usage-side flow rate adjustment valve 42a to become a low-pressure gas-liquid two-phase state, and through the first usage-side liquid refrigerant tube 45a, It is sent to the first usage side heat exchanger 41a. The low-pressure heat-source-side refrigerant sent to the first usage-side heat exchanger 41a exchanges heat with the high-pressure usage-side refrigerant in the refrigeration cycle circulating in the usage-side refrigerant circuit 40a in the first usage-side heat exchanger 41a. Evaporate. The low-pressure heat-source-side refrigerant evaporated in the first usage-side heat exchanger 41a is sent from the first usage unit 4a to the gas refrigerant communication tube 14 through the first usage-side gas refrigerant tube 54a.

  The heat source side refrigerant sent from the first usage unit 4 a to the gas refrigerant communication tube 14 is sent to the heat source unit 2. The low-pressure heat source side refrigerant sent to the heat source unit 2 is sent to the heat source side accumulator 28 through the gas side shut-off valve 30, the second heat source side gas refrigerant tube 23b, and the heat source side switching mechanism 23. The low-pressure heat source side refrigerant sent to the heat source side accumulator 28 is again sucked into the heat source side compressor 21 through the heat source side suction pipe 21c.

  On the other hand, in the usage-side refrigerant circuit 40a, the high-pressure usage-side refrigerant in the refrigeration cycle that circulates in the usage-side refrigerant circuit 40a is radiated by evaporation of the heat source-side refrigerant in the first usage-side heat exchanger 41a. The high-pressure use-side refrigerant that has radiated heat in the first use-side heat exchanger 41a is sent to the refrigerant-water heat exchange side flow rate adjustment valve 66a. The high-pressure use-side refrigerant sent to the refrigerant-water heat exchange side flow rate adjustment valve 66a is depressurized by the refrigerant-water heat exchange side flow rate adjustment valve 66a to become a low-pressure gas-liquid two-phase state, and the cascade-side liquid refrigerant. It is sent to the refrigerant-water heat exchanger 65a through the pipe 68a. The low-pressure use-side refrigerant sent to the refrigerant-water heat exchanger 65a evaporates in the refrigerant-water heat exchanger 65a by exchanging heat with the aqueous medium circulating in the aqueous medium circuit 80a by the circulation pump 43a. The low-pressure usage-side refrigerant evaporated in the refrigerant-water heat exchanger 65a is sent to the usage-side accumulator 67a through the first cascade-side gas refrigerant tube 72a and the first usage-side switching mechanism 64a. The low-pressure use-side refrigerant sent to the use-side accumulator 67a is sucked into the use-side compressor 62a through the cascade-side suction pipe 71a, compressed to a high pressure in the refrigeration cycle, and then discharged to the cascade-side discharge pipe 70a. . The high-pressure use-side refrigerant discharged to the cascade-side discharge pipe 70a is sent again to the first use-side heat exchanger 41a through the first use-side switching mechanism 64a and the second cascade-side gas refrigerant pipe 69a.

  In this way, the heat source side heat exchanger 24 functions as a heat source side refrigerant radiator by setting the heat source side switching mechanism 23 to the heat source side heat radiation operation state, and the first usage side switching mechanism 64a is utilized on the usage side evaporation operation. In this state, the refrigerant-water heat exchanger 65a functions as an evaporator for the use side refrigerant, and the first use side heat exchanger 41a serves as a radiator for the use side refrigerant (that is, the evaporator of the heat source side refrigerant). As)) to start functioning defrosting operation.

  Then, it is determined whether or not a predetermined defrosting operation end condition is satisfied (that is, whether or not the defrosting of the heat source side heat exchanger 24 is completed) (step S23). Here, whether or not the heat source side heat exchanger temperature Thx has reached a predetermined defrosting completion temperature Thxs or a defrosting operation time tdf that is an elapsed time from the start of the defrosting operation is a predetermined defrosting operation setting time tdfs. It is determined whether or not the defrosting operation end condition is satisfied depending on whether or not it has been reached.

  And when it determines with satisfy | filling the defrost operation completion | finish conditions, the process which complete | finishes a defrost operation and returns to hot water supply operation mode is performed (step S24).

  Thereby, in this heat pump system 1, when defrosting the heat source side heat exchanger 24, the heat source side heat exchanger 24 is made into the heat source side heat dissipation operation state by setting the heat source side switching mechanism 23 to the heat source side heat dissipation operation state. In addition, the refrigerant-water heat exchanger 65a functions as an evaporator for the use-side refrigerant by setting the first use-side switching mechanism 64a to the use-side evaporation operation state, and the first use-side heat exchange is performed. Since the heat exchanger 41a is caused to function as a radiator for the use side refrigerant, the heat source side refrigerant radiated and cooled by the heat source side heat exchanger 24 is radiated by the first use side heat exchanger 41a. The use-side refrigerant that has been heated by the heat and radiated and cooled in the first use-side heat exchanger 41a can be heated by evaporating in the refrigerant-water heat exchanger 65a. Accordingly, the defrosting of the heat source-side heat exchanger 24 can be reliably performed. In addition, the pressure equalization sound of the use side refrigerant circuit 40a when performing the defrosting operation is prevented from becoming excessive, and the pressure equalization in the use side refrigerant circuit 40a can be quickly performed.

(3) Modification 3
In the heat pump system 1 described above (see FIGS. 1 and 4), one first usage unit 4a is connected to the heat source unit 2 via the refrigerant communication pipes 13 and 14, as shown in FIG. Here, the hot water heating unit, the hot water storage unit, the aqueous medium circuits 80a, 80b, etc. are not shown), and a plurality (here, two) of the first usage units 4a, 4b are connected via the refrigerant communication tubes 13, 14. , Each other may be connected in parallel. Since the configuration of the first usage unit 4b is the same as that of the first usage unit 4a, the configuration of the first usage unit 4b is indicated by a suffix “a” indicating each part of the first usage unit 4a. Subscript “b” is attached instead of “,” and description of each part is omitted.

  Thereby, in this heat pump system 1, it can respond to a plurality of places and uses which require heating of an aqueous medium.

(Second Embodiment)
In heat pump system 1 (refer to Drawing 1, Drawing 4, and Drawing 6) in the above-mentioned 1st embodiment and its modification, it is preferred that not only hot water supply operation but indoor heating can be performed.

  Therefore, in the heat pump system 200, in the configuration of the heat pump system 1 (see FIG. 1) according to the above-described first embodiment, as shown in FIG. A second use side heat exchanger 101a capable of heating is further provided in the heat source side refrigerant circuit 20. Hereinafter, the configuration of the heat pump system 200 will be described.

<Configuration>
-Overall-
FIG. 7 is a schematic configuration diagram of a heat pump system 200 according to the second embodiment of the present invention. The heat pump system 200 is an apparatus that can perform an operation of heating an aqueous medium using a vapor compression heat pump cycle.

  The heat pump system 200 mainly includes a heat source unit 2, a first usage unit 4a, a second usage unit 10a, a liquid refrigerant communication tube 13, a gas refrigerant communication tube 14, a hot water storage unit 8a, and a hot water heating unit 9a. The aqueous medium communication pipe 15a and the aqueous medium communication pipe 16a are provided, and the heat source unit 2, the first usage unit 4a, and the second usage unit 10a are connected via the refrigerant communication tubes 13 and 14. The heat source side refrigerant circuit 20 is configured, the first usage unit 4a constitutes the usage side refrigerant circuit 40a, and the first usage unit 4a, the hot water storage unit 8a, and the hot water heating unit 9a are connected via the aqueous medium communication pipes 15a and 16a. Thus, the aqueous medium circuit 80a is configured. The heat source side refrigerant circuit 20 contains HFC-410A, which is a kind of HFC refrigerant, as a heat source refrigerant, and ester or ether refrigerating machine oil that is compatible with the HFC refrigerant is a heat source. The side compressor 22 is sealed for lubrication. Further, HFC-134a, which is a kind of HFC refrigerant, is sealed in the use side refrigerant circuit 40a as a use side refrigerant, and ester or ether type refrigerating machine oil having compatibility with the HFC refrigerant. Is enclosed for lubrication of the use side compressor 62a. In addition, as a use side refrigerant | coolant, from a viewpoint that the refrigerant | coolant advantageous to a high temperature refrigerating cycle is used, the pressure corresponding to saturation gas temperature 65 degreeC is 2.8 Mpa or less at the maximum at a gauge pressure, Preferably, it is 2.0 Mpa. The following refrigerants are preferably used. HFC-134a is a kind of refrigerant having such saturation pressure characteristics. Further, water as an aqueous medium circulates in the aqueous medium circuit 80a.

  In the following description of the configuration, the heat source unit 2, the first usage unit 4a, the hot water storage unit 8a, the hot water heating unit 9a, and the liquid refrigerant communication having the same configuration as the heat pump system 1 (see FIG. 1) in the first embodiment. About the structure of the pipe | tube 13, the gas refrigerant | coolant connecting pipe 14, and the aqueous medium connecting pipe 15a, 16a, the same code | symbol is attached | subjected and description is abbreviate | omitted and only the structure of the 2nd utilization unit 10a is demonstrated.

-Second usage unit-
The second usage unit 10a is installed indoors, is connected to the heat source unit 2 via the refrigerant communication tubes 13 and 14, and constitutes a part of the heat source side refrigerant circuit 20.

  The second usage unit 10a mainly includes a second usage-side heat exchanger 101a and a second usage-side flow rate adjustment valve 102a.

  The second usage-side heat exchanger 101a is a heat exchanger that functions as a heat-source-side refrigerant radiator or evaporator by exchanging heat between the heat-source-side refrigerant and indoor air as an air medium. A second usage-side liquid refrigerant pipe 103a is connected, and a second usage-side gas refrigerant pipe 104a is connected to the gas side thereof. A liquid refrigerant communication tube 13 is connected to the second usage side liquid refrigerant tube 103a, and a gas refrigerant communication tube 14 is connected to the second usage side gas refrigerant tube 104a. The air medium that exchanges heat with the heat source side refrigerant in the second usage side heat exchanger 101a is supplied by the usage side fan 105a driven by the usage side fan motor 106a.

  The second usage-side flow rate adjustment valve 102a is an electric expansion valve capable of varying the flow rate of the heat source-side refrigerant flowing through the second usage-side heat exchanger 101a by performing opening degree control. It is provided in the refrigerant pipe 103a.

  Thus, the second usage unit 10a causes the second usage-side heat exchanger 101a to function as an evaporator of the heat-source-side refrigerant introduced from the liquid refrigerant communication tube 13 when the heat-source-side switching mechanism 23 is in the heat-source-side heat radiation operation state. Thus, the cooling operation in which the heat source side refrigerant evaporated in the second usage side heat exchanger 101a is led out to the gas refrigerant communication tube 14 and the air medium is cooled by the evaporation of the heat source side refrigerant in the second usage side heat exchanger 101a. And the second use side heat exchanger 101a functions as a heat source side refrigerant radiator introduced from the gas refrigerant communication tube 14 in the heat source side evaporation operation state when the heat source side switching mechanism 23 is The heat source side refrigerant radiated in the second usage side heat exchanger 101a is led out to the liquid refrigerant communication tube 13, and the air medium is released by the heat dissipation of the heat source side refrigerant in the second usage side heat exchanger 101a. It becomes possible to perform the heating operation for heating.

  Various sensors are provided in the second usage unit 10a. Specifically, the second usage unit 10a is provided with an indoor temperature sensor 107a that detects the indoor temperature Tr.

<Operation>
Next, the operation of the heat pump system 200 will be described.

  The operation mode of the heat pump system 200 includes a hot water supply operation mode in which only the hot water supply operation of the first usage unit 4a (that is, the operation of the hot water storage unit 8a and / or the hot water heating unit 9a) and the cooling operation of the second usage unit 10a are performed. A cooling operation mode for performing the heating operation mode for performing only the heating operation of the second usage unit 10a, and a hot water supply and heating operation mode for performing the hot water supply operation of the first usage unit 4a and performing the heating operation of the second usage unit 10a. is there.

  Hereinafter, operations in the four operation modes of the heat pump system 200 will be described.

-Hot water operation mode-
When only the hot water supply operation of the first usage unit 4a is performed, in the heat source side refrigerant circuit 20, the heat source side switching mechanism 23 is in the heat source side evaporation operation state (the state indicated by the broken line of the heat source side switching mechanism 23 in FIG. 7). ), And the suction return expansion valve 26a and the second usage-side flow rate adjustment valve 102a are closed. In the aqueous medium circuit 80a, the aqueous medium switching mechanism 161a is switched to a state in which the aqueous medium is supplied to the hot water storage unit 8a and / or the hot water heating unit 9a.

  In the heat source side refrigerant circuit 20 in such a state, the low pressure heat source side refrigerant in the refrigeration cycle is sucked into the heat source side compressor 21 through the heat source side suction pipe 21c and compressed to a high pressure in the refrigeration cycle, and then the heat source side refrigerant circuit 20 is cooled. It is discharged to the discharge pipe 21b. The high pressure heat source side refrigerant discharged to the heat source side discharge pipe 21b is separated from the refrigerating machine oil in the oil separator 22a. The refrigerating machine oil separated from the heat source side refrigerant in the oil separator 22a is returned to the heat source side suction pipe 21c through the oil return pipe 22b. The high-pressure heat source side refrigerant from which the refrigerating machine oil is separated is sent from the heat source unit 2 to the gas refrigerant communication tube 14 through the heat source side switching mechanism 23, the second heat source side gas refrigerant tube 23b, and the gas side shut-off valve 30.

  The high-pressure heat-source-side refrigerant sent to the gas refrigerant communication tube 14 is sent to the first usage unit 4a. The high-pressure heat-source-side refrigerant sent to the first usage unit 4a is sent to the first usage-side heat exchanger 41a through the first usage-side gas refrigerant tube 54a. The high-pressure heat-source-side refrigerant sent to the first usage-side heat exchanger 41a exchanges heat with the low-pressure usage-side refrigerant in the refrigeration cycle circulating in the usage-side refrigerant circuit 40a in the first usage-side heat exchanger 41a. To dissipate heat. The high-pressure heat-source-side refrigerant radiated in the first usage-side heat exchanger 41a is sent from the first usage unit 4a to the liquid refrigerant communication tube 13 through the first usage-side flow rate adjustment valve 42a and the first usage-side liquid refrigerant tube 45a. It is done.

  The heat source side refrigerant sent to the liquid refrigerant communication tube 13 is sent to the heat source unit 2. The heat source side refrigerant sent to the heat source unit 2 is sent to the supercooler 27 through the liquid side shut-off valve 29. The heat source side refrigerant sent to the subcooler 27 is sent to the heat source side expansion valve 25 without performing heat exchange because the heat source side refrigerant does not flow through the suction return pipe 26. The heat source side refrigerant sent to the heat source side expansion valve 25 is depressurized by the heat source side expansion valve 25 to be in a low-pressure gas-liquid two-phase state, and sent to the heat source side heat exchanger 24 through the heat source side liquid refrigerant tube 24a. It is done. The low-pressure refrigerant sent to the heat source side heat exchanger 24 evaporates by exchanging heat with outdoor air supplied by the heat source side fan 32 in the heat source side heat exchanger 24. The low-pressure heat source side refrigerant evaporated in the heat source side heat exchanger 24 is sent to the heat source side accumulator 28 through the first heat source side gas refrigerant tube 23a and the heat source side switching mechanism 23. The low-pressure heat source side refrigerant sent to the heat source side accumulator 28 is again sucked into the heat source side compressor 21 through the heat source side suction pipe 21c.

  On the other hand, in the usage-side refrigerant circuit 40a, the low-pressure usage-side refrigerant in the refrigeration cycle circulating in the usage-side refrigerant circuit 40a is heated and evaporated by the heat radiation of the heat-source-side refrigerant in the first usage-side heat exchanger 41a. The low-pressure usage-side refrigerant evaporated in the first usage-side heat exchanger 41a is sent to the usage-side accumulator 67a through the second cascade-side gas refrigerant tube 69a. The low-pressure use-side refrigerant sent to the use-side accumulator 67a is sucked into the use-side compressor 62a through the cascade-side suction pipe 71a, compressed to a high pressure in the refrigeration cycle, and then discharged to the cascade-side discharge pipe 70a. . The high-pressure use-side refrigerant discharged to the cascade-side discharge pipe 70a is sent to the refrigerant-water heat exchanger 65a through the first cascade-side gas refrigerant pipe 72a. The high-pressure usage-side refrigerant sent to the refrigerant-water heat exchanger 65a radiates heat by exchanging heat with the aqueous medium circulating in the aqueous medium circuit 80a by the circulation pump 43a in the refrigerant-water heat exchanger 65a. The high-pressure use-side refrigerant that has radiated heat in the refrigerant-water heat exchanger 65a is decompressed in the refrigerant-water heat exchange side flow rate adjustment valve 66a to become a low-pressure gas-liquid two-phase state, and through the cascade-side liquid refrigerant pipe 68a. Again, it is sent to the 1st utilization side heat exchanger 41a.

  In the aqueous medium circuit 80a, the aqueous medium circulating in the aqueous medium circuit 80a is heated by the heat radiation of the use-side refrigerant in the refrigerant-water heat exchanger 65a. The aqueous medium heated in the refrigerant-water heat exchanger 65a is drawn into the circulation pump 43a through the first usage-side water outlet pipe 48a, and after being pressurized, is sent from the first usage unit 4a to the aqueous medium communication pipe 16a. It is done. The aqueous medium sent to the aqueous medium communication pipe 16a is sent to the hot water storage unit 8a and / or the hot water heating unit 9a through the aqueous medium side switching mechanism 161a. The aqueous medium sent to the hot water storage unit 8a exchanges heat with the aqueous medium in the hot water storage tank 81a in the heat exchange coil 82a to radiate heat, thereby heating the aqueous medium in the hot water storage tank 81a. The aqueous medium sent to the hot water heating unit 9a dissipates heat in the heat exchange panel 91a, thereby heating the indoor wall or the like or heating the indoor floor.

  In this manner, the operation in the hot water supply operation mode in which only the hot water supply operation of the first usage unit 4a is performed is performed.

-Cooling operation mode-
When only the cooling operation of the second usage unit 10a is performed, in the heat source side refrigerant circuit 20, the heat source side switching mechanism 23 is in the heat source side heat dissipation operation state (the state shown by the solid line of the heat source side switching mechanism 23 in FIG. 7). ) And the first usage-side flow rate adjustment valve 42a is closed.

  In the heat source side refrigerant circuit 20 in such a state, the low pressure heat source side refrigerant in the refrigeration cycle is sucked into the heat source side compressor 21 through the heat source side suction pipe 21c and compressed to a high pressure in the refrigeration cycle, and then the heat source side refrigerant circuit 20 is cooled. It is discharged to the discharge pipe 21b. The high pressure heat source side refrigerant discharged to the heat source side discharge pipe 21b is separated from the refrigerating machine oil in the oil separator 22a. The refrigerating machine oil separated from the heat source side refrigerant in the oil separator 22a is returned to the heat source side suction pipe 21c through the oil return pipe 22b. The high-pressure heat-source-side refrigerant from which the refrigeration oil is separated is sent to the heat-source-side heat exchanger 24 through the heat-source-side switching mechanism 23 and the first heat-source-side gas refrigerant tube 23a. The high-pressure heat-source-side refrigerant sent to the heat-source-side heat exchanger 24 radiates heat by exchanging heat with outdoor air supplied by the heat-source-side fan 32 in the heat source-side heat exchanger 24. The high-pressure heat-source-side refrigerant that has radiated heat in the heat-source-side heat exchanger is sent to the supercooler 27 through the heat source-side expansion valve 25. The heat-source-side refrigerant sent to the subcooler 27 is cooled so as to be in a supercooled state by exchanging heat with the heat-source-side refrigerant branched from the heat source-side liquid refrigerant tube 24a to the suction return tube 26. The heat source side refrigerant flowing through the suction return pipe 26 is returned to the heat source side suction pipe 21c. The heat source side refrigerant cooled in the subcooler 27 is sent from the heat source unit 2 to the liquid refrigerant communication tube 13 through the heat source side liquid refrigerant tube 24a and the liquid side shut-off valve 29.

  The high-pressure heat-source-side refrigerant sent to the liquid refrigerant communication tube 13 is sent to the second usage unit 10a. The high-pressure heat-source-side refrigerant sent to the second usage unit 10a is sent to the second usage-side flow rate adjustment valve 102a. The high-pressure heat-source-side refrigerant sent to the second usage-side flow rate adjustment valve 102a is depressurized by the second usage-side flow rate adjustment valve 102a to become a low-pressure gas-liquid two-phase state, and the second usage-side liquid refrigerant tube 103a. To the second usage side heat exchanger 101a. The low-pressure heat source side refrigerant sent to the second usage side heat exchanger 101a evaporates by exchanging heat with the air medium supplied by the usage side fan 105a in the second usage side heat exchanger 101a. Cool the room. The low-pressure heat-source-side refrigerant evaporated in the second usage-side heat exchanger 101a is sent from the second usage unit 10a to the gas refrigerant communication tube 14 through the second usage-side gas refrigerant tube 104a.

  The low-pressure heat source side refrigerant sent to the gas refrigerant communication tube 14 is sent to the heat source unit 2. The low-pressure heat source side refrigerant sent to the heat source unit 2 is sent to the heat source side accumulator 28 through the gas side shut-off valve 30, the second heat source side gas refrigerant tube 23b, and the heat source side switching mechanism 23. The low-pressure heat source side refrigerant sent to the heat source side accumulator 28 is again sucked into the heat source side compressor 21 through the heat source side suction pipe 21c.

  In this manner, the operation in the cooling operation mode in which only the cooling operation of the second usage unit 10a is performed is performed.

−Heating operation mode−
When only the heating operation of the second usage unit 10a is performed, in the heat source side refrigerant circuit 20, the heat source side switching mechanism 23 is in the heat source side heat radiation operation state (the state shown by the broken line of the heat source side switching mechanism 23 in FIG. And the suction return expansion valve 26a and the first usage-side flow rate adjustment valve 42a are closed.

  In the heat source side refrigerant circuit 20 in such a state, the low pressure heat source side refrigerant in the refrigeration cycle is sucked into the heat source side compressor 21 through the heat source side suction pipe 21c and compressed to a high pressure in the refrigeration cycle, and then the heat source side refrigerant circuit 20 is cooled. It is discharged to the discharge pipe 21b. The high pressure heat source side refrigerant discharged to the heat source side discharge pipe 21b is separated from the refrigerating machine oil in the oil separator 22a. The refrigerating machine oil separated from the heat source side refrigerant in the oil separator 22a is returned to the heat source side suction pipe 21c through the oil return pipe 22b. The high-pressure heat source side refrigerant from which the refrigerating machine oil is separated is sent from the heat source unit 2 to the gas refrigerant communication tube 14 through the heat source side switching mechanism 23, the second heat source side gas refrigerant tube 23b, and the gas side shut-off valve 30.

  The high-pressure heat source-side refrigerant sent to the gas refrigerant communication tube 14 is sent to the second usage unit 10a. The high-pressure heat-source-side refrigerant sent to the second usage unit 10a is sent to the second usage-side heat exchanger 101a through the second usage-side gas refrigerant tube 104a. The high-pressure heat-source-side refrigerant sent to the second usage-side heat exchanger 101a radiates heat by exchanging heat with the air medium supplied by the usage-side fan 105a in the second usage-side heat exchanger 101a. , Heating the room. The high-pressure heat-source-side refrigerant radiated in the second usage-side heat exchanger 101a is sent from the second usage unit 10a to the liquid refrigerant communication tube 13 through the second usage-side flow rate adjustment valve 102a and the second usage-side liquid refrigerant tube 103a. It is done.

  The heat source side refrigerant sent to the liquid refrigerant communication tube 13 is sent to the heat source unit 2. The heat source side refrigerant sent to the heat source unit 2 is sent to the supercooler 27 through the liquid side shut-off valve 29. The heat source side refrigerant sent to the subcooler 27 is sent to the heat source side expansion valve 25 without performing heat exchange because the heat source side refrigerant does not flow through the suction return pipe 26. The heat source side refrigerant sent to the heat source side expansion valve 25 is depressurized by the heat source side expansion valve 25 to be in a low-pressure gas-liquid two-phase state, and sent to the heat source side heat exchanger 24 through the heat source side liquid refrigerant tube 24a. It is done. The low-pressure refrigerant sent to the heat source side heat exchanger 24 evaporates by exchanging heat with outdoor air supplied by the heat source side fan 32 in the heat source side heat exchanger 24. The low-pressure heat source side refrigerant evaporated in the heat source side heat exchanger 24 is sent to the heat source side accumulator 28 through the first heat source side gas refrigerant tube 23a and the heat source side switching mechanism 23. The low-pressure heat source side refrigerant sent to the heat source side accumulator 28 is again sucked into the heat source side compressor 21 through the heat source side suction pipe 21c.

  Thus, the operation | movement in the heating operation mode which performs only the heating operation of the 2nd utilization unit 10a is performed.

-Hot water heating / heating mode-
When the hot water supply operation of the first usage unit 4a is performed and the heating operation of the second usage unit 10a is performed, in the heat source side refrigerant circuit 20, the heat source side switching mechanism 23 is in the heat source side evaporation operation state (the heat source side in FIG. 7). (The state indicated by the broken line of the switching mechanism 23), and the suction return expansion valve 26a is closed. In the aqueous medium circuit 80a, the aqueous medium switching mechanism 161a is switched to a state in which the aqueous medium is supplied to the hot water storage unit 8a and / or the hot water heating unit 9a.

  In the heat source side refrigerant circuit 20 in such a state, the low pressure heat source side refrigerant in the refrigeration cycle is sucked into the heat source side compressor 21 through the heat source side suction pipe 21c and compressed to a high pressure in the refrigeration cycle, and then the heat source side refrigerant circuit 20 is cooled. It is discharged to the discharge pipe 21b. The high pressure heat source side refrigerant discharged to the heat source side discharge pipe 21b is separated from the refrigerating machine oil in the oil separator 22a. The refrigerating machine oil separated from the heat source side refrigerant in the oil separator 22a is returned to the heat source side suction pipe 21c through the oil return pipe 22b. The high-pressure heat source side refrigerant from which the refrigerating machine oil is separated is sent from the heat source unit 2 to the gas refrigerant communication tube 14 through the heat source side switching mechanism 23, the second heat source side gas refrigerant tube 23b, and the gas side shut-off valve 30.

  The high-pressure heat-source-side refrigerant sent to the gas refrigerant communication tube 14 is sent to the first usage unit 4a and the second usage unit 10a.

  The high-pressure heat-source-side refrigerant sent to the second usage unit 10a is sent to the second usage-side heat exchanger 101a through the second usage-side gas refrigerant tube 104a. The high-pressure heat-source-side refrigerant sent to the second usage-side heat exchanger 101a radiates heat by exchanging heat with the air medium supplied by the usage-side fan 105a in the second usage-side heat exchanger 101a. , Heating the room. The high-pressure heat-source-side refrigerant radiated in the second usage-side heat exchanger 101a is sent from the second usage unit 10a to the liquid refrigerant communication tube 13 through the second usage-side flow rate adjustment valve 102a and the second usage-side liquid refrigerant tube 103a. It is done.

  The high-pressure heat-source-side refrigerant sent to the first usage unit 4a is sent to the first usage-side heat exchanger 41a through the first usage-side gas refrigerant tube 54a. The high-pressure heat-source-side refrigerant sent to the first usage-side heat exchanger 41a exchanges heat with the low-pressure usage-side refrigerant in the refrigeration cycle circulating in the usage-side refrigerant circuit 40a in the first usage-side heat exchanger 41a. To dissipate heat. The high-pressure heat-source-side refrigerant radiated in the first usage-side heat exchanger 41a is sent from the first usage unit 4a to the liquid refrigerant communication tube 13 through the first usage-side flow rate adjustment valve 42a and the first usage-side liquid refrigerant tube 45a. It is done.

  The heat source side refrigerant sent from the second usage unit 10a and the first usage unit 4a to the liquid refrigerant communication tube 13 merges in the liquid refrigerant communication tube 13 and is sent to the heat source unit 2. The heat source side refrigerant sent to the heat source unit 2 is sent to the supercooler 27 through the liquid side shut-off valve 29. The heat source side refrigerant sent to the subcooler 27 is sent to the heat source side expansion valve 25 without performing heat exchange because the heat source side refrigerant does not flow through the suction return pipe 26. The heat source side refrigerant sent to the heat source side expansion valve 25 is depressurized by the heat source side expansion valve 25 to be in a low-pressure gas-liquid two-phase state, and sent to the heat source side heat exchanger 24 through the heat source side liquid refrigerant tube 24a. It is done. The low-pressure refrigerant sent to the heat source side heat exchanger 24 evaporates by exchanging heat with outdoor air supplied by the heat source side fan 32 in the heat source side heat exchanger 24. The low-pressure heat source side refrigerant evaporated in the heat source side heat exchanger 24 is sent to the heat source side accumulator 28 through the first heat source side gas refrigerant tube 23a and the heat source side switching mechanism 23. The low-pressure heat source side refrigerant sent to the heat source side accumulator 28 is again sucked into the heat source side compressor 21 through the heat source side suction pipe 21c.

  On the other hand, in the usage-side refrigerant circuit 40a, the low-pressure usage-side refrigerant in the refrigeration cycle circulating in the usage-side refrigerant circuit 40a is heated and evaporated by the heat radiation of the heat-source-side refrigerant in the first usage-side heat exchanger 41a. The low-pressure usage-side refrigerant evaporated in the first usage-side heat exchanger 41a is sent to the usage-side accumulator 67a through the second cascade-side gas refrigerant tube 69a. The low-pressure use-side refrigerant sent to the use-side accumulator 67a is sucked into the use-side compressor 62a through the cascade-side suction pipe 71a, compressed to a high pressure in the refrigeration cycle, and then discharged to the cascade-side discharge pipe 70a. . The high-pressure use-side refrigerant discharged to the cascade-side discharge pipe 70a is sent to the refrigerant-water heat exchanger 65a through the first cascade-side gas refrigerant pipe 72a. The high-pressure usage-side refrigerant sent to the refrigerant-water heat exchanger 65a radiates heat by exchanging heat with the aqueous medium circulating in the aqueous medium circuit 80a by the circulation pump 43a in the refrigerant-water heat exchanger 65a. The high-pressure use-side refrigerant that has radiated heat in the refrigerant-water heat exchanger 65a is decompressed in the refrigerant-water heat exchange side flow rate adjustment valve 66a to become a low-pressure gas-liquid two-phase state, and through the cascade-side liquid refrigerant pipe 68a. Again, it is sent to the 1st utilization side heat exchanger 41a.

  In the aqueous medium circuit 80a, the aqueous medium circulating in the aqueous medium circuit 80a is heated by the heat radiation of the use-side refrigerant in the refrigerant-water heat exchanger 65a. The aqueous medium heated in the refrigerant-water heat exchanger 65a is drawn into the circulation pump 43a through the first usage-side water outlet pipe 48a, and after being pressurized, is sent from the first usage unit 4a to the aqueous medium communication pipe 16a. It is done. The aqueous medium sent to the aqueous medium communication pipe 16a is sent to the hot water storage unit 8a and / or the hot water heating unit 9a through the aqueous medium side switching mechanism 161a. The aqueous medium sent to the hot water storage unit 8a exchanges heat with the aqueous medium in the hot water storage tank 81a in the heat exchange coil 82a to radiate heat, thereby heating the aqueous medium in the hot water storage tank 81a. The aqueous medium sent to the hot water heating unit 9a dissipates heat in the heat exchange panel 91a, thereby heating the indoor wall or the like or heating the indoor floor.

  Thus, the operation in the hot water supply / heating operation mode in which the hot water supply operation of the first usage unit 4a is performed and the heating operation of the second usage unit 10a is performed is performed.

  Here, also in the configuration of the heat pump system 200 in which the first usage unit 4a for hot water supply operation and the second usage unit 10a for air conditioning operation are connected to the heat source unit 2, the heat pump system 1 in the first embodiment (FIG. 1). In the same manner as in the above, the discharge saturation temperature control of the refrigerant circuits 20 and 40a, the supercooling degree control of the outlets of the heat exchangers 41a and 65a, the flow control of the aqueous medium circulating in the aqueous medium circuit 80a, and the circuits 20 , 40a, and 80a are controlled.

  However, among these controls, for the discharge saturation temperature control of the heat source side refrigerant circuit 20, the second usage side heat exchanger 101a is connected, and the second usage side heat exchanger 101a is connected to the heat source side refrigerant radiator. Therefore, the heat source side refrigerant having the heat source side discharge saturation temperature Tc1 suitable for heating the air medium needs to be supplied to the second usage side heat exchanger 101a.

  Therefore, in the discharge saturation temperature control of the heat source side refrigerant circuit 20 in the heat pump system 200, when performing an operation for causing the second usage side heat exchanger 101a to function as a heat source side refrigerant radiator (here, the heating operation mode and the hot water supply) In the heating operation mode), the target heat source side discharge saturation temperature is higher than in the case where the operation for causing the second usage side heat exchanger 101a to function as a heat source side refrigerant radiator is not performed (here, the hot water supply operation mode and the cooling operation mode). Tc1s is increased. More specifically, in the heat pump system 1 in the first embodiment (that is, this heat pump system 200 corresponds to the case where the operation for causing the second usage-side heat exchanger 101a to function as a heat-source-side refrigerant radiator is not performed). When the temperature range of the target heat source side discharge saturation temperature Tc1s is controlled to be a temperature range of 10 ° C. to 40 ° C., in this heat pump system 200, the second usage side heat exchanger 101a is radiated by the heat source side refrigerant. When the operation to function as a heater is not performed (here, the hot water supply operation mode and the cooling operation mode), the temperature range of the target heat source side discharge saturation temperature Tc1s is set to 10 ° C. to 40 similarly to the heat pump system 1 in the first embodiment. And control the second use side heat exchanger 101a as a heat source side refrigerant radiator. When the operation is performed (here, the heating operation mode or the hot water supply / heating operation mode), the temperature range of the target heat source side discharge saturation temperature Tc1s is higher than the temperature range of 10 ° C to 40 ° C, and is a temperature of 40 ° C to 50 ° C. It is controlled to be in range.

  As a result, when the operation for causing the second usage-side heat exchanger 101a to function as a heat-source-side refrigerant radiator is not performed, the refrigeration cycle in the heat-source-side refrigerant circuit 20 is performed at a pressure as low as possible. In the case where the operation efficiency is increased in the refrigerant circuit 20 and the second usage side heat exchanger 101a is operated to function as a heat source side refrigerant radiator, the second usage side heat exchanger 101a is used to heat the air medium. A heat source side refrigerant having a suitable saturation temperature can be supplied.

<Features>
The heat pump system 200 has the following characteristics.

-A-
In the heat pump system 200, the same effect as the heat pump system 1 in the first embodiment can be obtained, and the second usage unit 10a including the second usage-side heat exchanger 101a is provided, and the second usage Operation for heating the air medium by heat radiation of the heat source side refrigerant in the side heat exchanger 101a (here, heating operation) and operation for cooling the air medium by evaporation of the heat source side refrigerant in the second usage side heat exchanger 101a (here) , Cooling operation) can be performed, so that not only the aqueous medium heated in the first use side heat exchanger 41a and the use side refrigerant circuit 40a is used for hot water supply, but also the second use heat exchange. The air medium heated in the vessel 101a can be used for room heating.

-B-
In this heat pump system 200, in the discharge saturation temperature control of the heat source side refrigerant circuit 20, when the second use side heat exchanger 101a is operated to function as a heat source side refrigerant radiator (here, heating operation mode or hot water supply heating) In the operation mode), the target heat source side discharge saturation temperature Tc1s is higher than in the case where the operation for causing the second usage side heat exchanger 101a to function as the heat source side refrigerant radiator is not performed (here, the hot water supply operation mode and the cooling operation mode). Therefore, when the operation for causing the second usage-side heat exchanger 101a to function as a heat-source-side refrigerant radiator is not performed, the refrigeration cycle in the heat-source-side refrigerant circuit 20 is performed at as low a pressure as possible. In this way, the operation efficiency in the heat source side refrigerant circuit 20 is increased, and the second usage side heat exchanger 101a is radiated by the heat source side refrigerant. When performing the operation to function as may be the second usage-side heat exchanger 101a is supplied to the heat source side refrigerant saturation temperature suitable for heating the air medium.

(1) Modification 1
Even in a configuration in which the first use unit 4a for hot water supply operation and the second use unit 10a for air conditioning operation are connected to the heat source unit 2 as in the above-described heat pump system 200 (see FIG. 7), the first embodiment is also used. Similarly to the heat pump system 1 (see FIG. 1) of the first modification, when supply of an aqueous medium with a wide temperature is required, the use side discharge that is the pressure of the use side refrigerant in the discharge of the use side compressor 62a The use side inlet / outlet pressure difference ΔP2 which is the pressure difference between the pressure Pd2 and the use side suction pressure Pd2 which is the pressure of the use side refrigerant in the suction of the use side compressor 62a becomes very small, and the use side refrigerant circuit 40a has a low load. Since the operation is required, there is a possibility that the refrigeration cycle of the use side refrigerant circuit 40a cannot be controlled only by the capacity control of the use side compressor 62a. Insufficient lubrication even cause that occurs bad circulation of the refrigerating machine oil in the usage-side compressor in 62a.

  Therefore, in the heat pump system 200, the use side low-load operation control (see FIG. 3) similar to the heat pump system 1 (see FIG. 1) in the first embodiment is performed.

  Thereby, even when the use side inlet / outlet pressure difference ΔP2 is very small, the flow rate of the heat source side refrigerant flowing into the first use side heat exchanger 41a is reduced, and the heat in the first use side heat exchanger 41a is reduced. The use side refrigerant circuit 40a can be easily operated even under a low load condition by suppressing the exchange capacity so that the use side inlet / outlet pressure difference ΔP2 is increased. be able to.

(2) Modification 2
Even in a configuration in which the first use unit 4a for hot water supply operation and the second use unit 10a for air conditioning operation are connected to the heat source unit 2 as in the above-described heat pump system 200 (see FIG. 7), the first embodiment is also used. As in the heat pump system 1 (see FIG. 4) in the second modified example, as shown in FIG. 8, the refrigerant-water heat exchanger 65a functions as a radiator for the utilization side refrigerant and the first utilization side heat exchanger. The utilization side heat radiation operation state in which 41a functions as a utilization side refrigerant evaporator, and the refrigerant-water heat exchanger 65a functions as a utilization side refrigerant evaporator and the first utilization side heat exchanger 41a serves as a utilization side refrigerant radiator. The use side refrigerant circuit 40a may be further provided with a first use side switching mechanism 64a capable of switching between the use side evaporation operation state to function as.

  In the heat pump system 200 having such a configuration, when it is determined that defrosting of the heat source side heat exchanger 24 is necessary by operations in the hot water supply operation mode, the heating operation mode, or the hot water supply heating operation mode, the heat source side By setting the switching mechanism 23 to the heat source side heat radiation operation state, the heat source side heat exchanger 24 functions as a heat source side refrigerant radiator and the second usage side heat exchanger 101a functions as a heat source side refrigerant evaporator. In addition, the refrigerant-water heat exchanger 65a functions as an evaporator of the usage-side refrigerant by setting the first usage-side switching mechanism 64a to the usage-side evaporation operation state, and the first usage-side heat exchanger 41a is used on the usage side. A defrosting operation that functions as a radiator of the refrigerant can be performed.

  Hereinafter, the operation in the defrosting operation will be described with reference to FIG.

  First, it is determined whether or not a predetermined defrosting operation start condition is satisfied (that is, whether or not the heat source side heat exchanger 24 needs to be defrosted) (step S21). Here, whether or not the defrosting operation start condition is satisfied depends on whether or not the defrosting time interval Δtdf (that is, the accumulated operation time from the end of the previous defrosting operation) has reached a predetermined defrosting time interval set value Δtdfs. judge.

  And when it determines with satisfy | filling the defrost operation start conditions, the following defrost operations are started (step S22).

  When starting the defrosting operation, in the heat source side refrigerant circuit 20, the heat source side switching mechanism 23 is switched to the heat source side heat radiation operation state (the state indicated by the solid line of the heat source side switching mechanism 23 in FIG. 8). In the usage-side refrigerant circuit 40a, the first usage-side switching mechanism 64a is switched to the usage-side evaporation operation state (the state indicated by the broken line of the first usage-side switching mechanism 64a in FIG. 8), and the suction return expansion valve 26a is It becomes a closed state.

  When the heat source side switching mechanism 23 is set to the heat source side heat radiation operation state and the first usage side switching mechanism 64a is switched to the usage side evaporation operation state, the refrigerant in each refrigerant circuit 20, 40a Is generated, and a noise (that is, a pressure equalization sound) at the time of pressure equalization of the refrigerant in each of the refrigerant circuits 20 and 40a is generated. However, it is possible to prevent such pressure equalization sound from becoming excessive. preferable.

  Therefore, in the heat pump system 200, when the defrosting operation is started, after the heat source side switching mechanism 23 is set to the heat source side heat radiation operation state, the first usage side switching mechanism 64a is set to the usage side evaporation operation state. The refrigerant in both refrigerant circuits 20 and 40a is prevented from being equalized simultaneously. Thereby, it is possible to prevent excessive pressure equalization when performing the defrosting operation.

  In the heat pump system 200, when the first usage side switching mechanism 64a is set to the usage side evaporation operation state, the usage side compressor 62a is stopped and the first usage side switching mechanism 64a is operated to the usage side evaporation operation. Since it is made into a state, it can prevent that the equalization sound in the utilization side refrigerant circuit 40a becomes large.

  Furthermore, in this heat pump system 200, when the use side compressor 62a is stopped, the refrigerant-water heat exchange side flow rate adjustment valve 66a remains open (more specifically, fully open). Since the use side compressor 62a is stopped, the pressure equalization in the use side refrigerant circuit 40a can be performed quickly.

  In the heat source side refrigerant circuit 20 in such a state, the low pressure heat source side refrigerant in the refrigeration cycle is sucked into the heat source side compressor 21 through the heat source side suction pipe 21c and compressed to a high pressure in the refrigeration cycle, and then the heat source side refrigerant circuit 20 is cooled. It is discharged to the discharge pipe 21b. The high pressure heat source side refrigerant discharged to the heat source side discharge pipe 21b is separated from the refrigerating machine oil in the oil separator 22a. The refrigerating machine oil separated from the heat source side refrigerant in the oil separator 22a is returned to the heat source side suction pipe 21c through the oil return pipe 22b. The high-pressure heat-source-side refrigerant from which the refrigeration oil is separated is sent to the heat-source-side heat exchanger 24 through the heat-source-side switching mechanism 23 and the first heat-source-side gas refrigerant tube 23a. The high-pressure heat-source-side refrigerant sent to the heat-source-side heat exchanger 24 radiates heat by exchanging heat with ice attached to the heat-source-side heat exchanger 24 in the heat-source-side heat exchanger 24. The high-pressure heat-source-side refrigerant that has radiated heat in the heat-source-side heat exchanger is sent to the supercooler 27 through the heat source-side expansion valve 25. Since the heat source side refrigerant sent to the subcooler 27 does not flow through the suction return pipe 26, the heat source unit refrigerant passes through the heat source side liquid refrigerant tube 24a and the liquid side shut-off valve 29 without performing heat exchange. 2 to the liquid refrigerant communication tube 13.

  The heat-source-side refrigerant sent to the liquid refrigerant communication tube 13 branches in the liquid refrigerant communication tube 13 and is sent to the first usage unit 4a and the second usage unit 10a.

  The heat-source-side refrigerant sent to the second usage unit 10a is sent to the second usage-side flow rate adjustment valve 102a. The heat-source-side refrigerant sent to the second usage-side flow rate adjustment valve 102a is depressurized by the second usage-side flow rate adjustment valve 102a to be in a low-pressure gas-liquid two-phase state, and through the second usage-side liquid refrigerant tube 103a, It is sent to the second usage side heat exchanger 101a. The low-pressure heat-source-side refrigerant sent to the second usage-side heat exchanger 101a evaporates by exchanging heat with the air medium supplied by the usage-side fan 105a in the second usage-side heat exchanger 101a. The low-pressure heat-source-side refrigerant evaporated in the second usage-side heat exchanger 101a is sent from the second usage unit 10a to the gas refrigerant communication tube 14 through the second usage-side gas refrigerant tube 104a.

  The heat-source-side refrigerant sent to the first usage unit 4a is sent to the first usage-side flow rate adjustment valve 42a. The heat-source-side refrigerant sent to the first usage-side flow rate adjustment valve 42a is depressurized in the first usage-side flow rate adjustment valve 42a to become a low-pressure gas-liquid two-phase state, and through the first usage-side liquid refrigerant tube 45a, It is sent to the first usage side heat exchanger 41a. The low-pressure heat-source-side refrigerant sent to the first usage-side heat exchanger 41a exchanges heat with the high-pressure usage-side refrigerant in the refrigeration cycle circulating in the usage-side refrigerant circuit 40a in the first usage-side heat exchanger 41a. Evaporate. The low-pressure heat-source-side refrigerant evaporated in the first usage-side heat exchanger 41a is sent from the first usage unit 4a to the gas refrigerant communication tube 14 through the first usage-side gas refrigerant tube 54a.

  The heat source side refrigerant sent from the second usage unit 10a and the first usage unit 4a to the gas refrigerant communication tube 14 merges in the gas refrigerant communication tube 14 and is sent to the heat source unit 2. The low-pressure heat source side refrigerant sent to the heat source unit 2 is sent to the heat source side accumulator 28 through the gas side shut-off valve 30, the second heat source side gas refrigerant tube 23b, and the heat source side switching mechanism 23. The low-pressure heat source side refrigerant sent to the heat source side accumulator 28 is again sucked into the heat source side compressor 21 through the heat source side suction pipe 21c.

  On the other hand, in the usage-side refrigerant circuit 40a, the high-pressure usage-side refrigerant in the refrigeration cycle that circulates in the usage-side refrigerant circuit 40a is radiated by evaporation of the heat source-side refrigerant in the first usage-side heat exchanger 41a. The high-pressure use-side refrigerant that has radiated heat in the first use-side heat exchanger 41a is sent to the refrigerant-water heat exchange side flow rate adjustment valve 66a. The high-pressure use-side refrigerant sent to the refrigerant-water heat exchange side flow rate adjustment valve 66a is depressurized by the refrigerant-water heat exchange side flow rate adjustment valve 66a to become a low-pressure gas-liquid two-phase state, and the cascade-side liquid refrigerant. It is sent to the refrigerant-water heat exchanger 65a through the pipe 68a. The low-pressure use-side refrigerant sent to the refrigerant-water heat exchanger 65a evaporates in the refrigerant-water heat exchanger 65a by exchanging heat with the aqueous medium circulating in the aqueous medium circuit 80a by the circulation pump 43a. The low-pressure usage-side refrigerant evaporated in the refrigerant-water heat exchanger 65a is sent to the usage-side accumulator 67a through the first cascade-side gas refrigerant tube 72a and the first usage-side switching mechanism 64a. The low-pressure use-side refrigerant sent to the use-side accumulator 67a is sucked into the use-side compressor 62a through the cascade-side suction pipe 71a, compressed to a high pressure in the refrigeration cycle, and then discharged to the cascade-side discharge pipe 70a. . The high-pressure use-side refrigerant discharged to the cascade-side discharge pipe 70a is sent again to the first use-side heat exchanger 41a through the first use-side switching mechanism 64a and the second cascade-side gas refrigerant pipe 69a.

  In this way, the heat source side heat exchanger 24 is caused to function as a heat source side refrigerant radiator by setting the heat source side switching mechanism 23 to the heat source side heat radiation operation state, and the second usage side heat exchanger 101a is set to the heat source side. The refrigerant-water heat exchanger 65a is caused to function as a use-side refrigerant evaporator by causing the first use-side switching mechanism 64a to be in a use-side evaporation operation state, while functioning as a refrigerant evaporator, and the first use side A defrosting operation for causing the heat exchanger 41a to function as a heat radiator for the use side refrigerant (that is, as an evaporator for the heat source side refrigerant) is started.

  Then, it is determined whether or not a predetermined defrosting operation end condition is satisfied (that is, whether or not the defrosting of the heat source side heat exchanger 24 is completed) (step S23). Here, whether or not the heat source side heat exchanger temperature Thx has reached a predetermined defrosting completion temperature Thxs or a defrosting operation time tdf that is an elapsed time from the start of the defrosting operation is a predetermined defrosting operation setting time tdfs. It is determined whether or not the defrosting operation end condition is satisfied depending on whether or not it has been reached.

  And when it determines with satisfy | filling the defrost operation completion | finish conditions, the process which complete | finishes a defrost operation and returns to hot water supply operation mode is performed (step S24).

  Thus, in the heat pump system 200, when the heat source side heat exchanger 24 is defrosted, the heat source side heat exchanger 24 is placed in the heat source side heat dissipation operation state by setting the heat source side switching mechanism 23 to the heat source side heat exchanger 24. In addition, the refrigerant-water heat exchanger 65a functions as an evaporator for the use-side refrigerant by setting the first use-side switching mechanism 64a to the use-side evaporation operation state, and the first use-side heat exchange is performed. Since the heat exchanger 41a is caused to function as a radiator for the use side refrigerant, the heat source side refrigerant radiated and cooled by the heat source side heat exchanger 24 is radiated by the first use side heat exchanger 41a. It is possible to heat the use-side refrigerant that has been heated by the heat and cooled in the first use-side heat exchanger 41a by evaporating in the refrigerant-water heat exchanger 65a. Thus, it is possible to reliably perform defrosting of the heat source-side heat exchanger 24. In addition, since the second usage-side heat exchanger 101a also functions as a heat source-side refrigerant evaporator, the defrosting operation time tdf can be shortened, and the air cooled in the second usage unit 10a. It can suppress that the temperature of a medium becomes low.

(3) Modification 3
In the above-described heat pump system 200 (see FIGS. 7 and 8), one first usage unit 4a and one second usage unit 10a are connected to the heat source unit 2 via the refrigerant communication tubes 13 and 14. 9 to 11 (here, illustration of the hot water heating unit, the hot water storage unit, the aqueous medium circuit 80a, 80b, etc. is omitted), a plurality of (here, two) first usage units 4a, 4b is connected to each other in parallel via the refrigerant communication pipes 13 and 14, and / or a plurality (two in this case) of the second usage units 10a and 10b are connected to the refrigerant communication pipe 13 , 14 may be connected to each other in parallel. Since the configuration of the first usage unit 4b is the same as that of the first usage unit 4a, the configuration of the first usage unit 4b is indicated by a suffix “a” indicating each part of the first usage unit 4a. Subscript “b” is attached instead of “,” and description of each part is omitted. In addition, since the configuration of the second usage unit 10b is the same as the configuration of the second usage unit 10a, the configuration of the second usage unit 10b is indicated by a suffix “a” indicating each part of the second usage unit 10a. Subscript “b” is attached instead of “,” and description of each part is omitted.

  Thereby, in these heat pump systems 200, it can respond to a plurality of places and uses which require heating of an aqueous medium, and can deal with a plurality of places and uses which require cooling of an air medium.

(4) Modification 4
In the above-described heat pump system 200 (see FIGS. 7 to 11), the second usage-side flow rate adjustment valves 102a and 102b are provided in the second usage units 10a and 10b, but as shown in FIG. Then, the hot water heating unit, the hot water storage unit, the aqueous medium circuit 80a, etc. are not shown), the second usage side flow rate adjustment valves 102a, 102b are omitted from the second usage units 10a, 10b, An expansion valve unit 17 having 102a and 102b may be provided.

(Third embodiment)
In the heat pump system 200 (see FIGS. 7 to 12) in the above-described second embodiment and its modification example, the hot water supply operation of the first usage unit 4a cannot be performed and the cooling operation of the second usage unit 10a cannot be performed. If such a hot water supply cooling operation can be performed, the hot water supply operation can be performed in an operation state in which the cooling operation is performed in summer or the like, which is preferable.

  Therefore, in this heat pump system 300, in the configuration of the heat pump system 200 (see FIG. 7) according to the second embodiment described above, the second usage-side heat exchanger 101a is evaporated of the heat source side refrigerant as shown in FIG. The air medium is cooled by functioning as a heater, and the hot water supply and cooling operation, which is an operation for heating the aqueous medium, can be performed by causing the first use side heat exchanger 41a to function as a heat radiator of the heat source side refrigerant. I have to. Hereinafter, the configuration of the heat pump system 300 will be described.

<Configuration>
-Overall-
FIG. 13 is a schematic configuration diagram of a heat pump system 300 according to the third embodiment of the present invention. The heat pump system 300 is an apparatus capable of performing an operation for heating an aqueous medium using a vapor compression heat pump cycle.

  The heat pump system 300 mainly includes a heat source unit 2, a first usage unit 4a, a second usage unit 10a, a discharge refrigerant communication tube 12, a liquid refrigerant communication tube 13, a gas refrigerant communication tube 14, and a hot water storage unit 8a. A hot water heating unit 9a, an aqueous medium communication pipe 15a, and an aqueous medium communication pipe 16a. The heat source unit 2, the first usage unit 4a, and the second usage unit 10a are connected to the refrigerant communication pipes 12, 13, 14, the heat source side refrigerant circuit 20 is constituted, the first usage unit 4a constitutes the usage side refrigerant circuit 40a, and the first usage unit 4a, the hot water storage unit 8a, and the hot water heating unit 9a are connected. The aqueous medium circuit 80a is configured by being connected via the aqueous medium communication pipes 15a and 16a. The heat source side refrigerant circuit 20 contains HFC-410A, which is a kind of HFC refrigerant, as a heat source refrigerant, and ester or ether refrigerating machine oil that is compatible with the HFC refrigerant is a heat source. The side compressor 22 is sealed for lubrication. Further, HFC-134a, which is a kind of HFC refrigerant, is sealed in the use side refrigerant circuit 40a as a use side refrigerant, and ester or ether type refrigerating machine oil having compatibility with the HFC refrigerant. Is enclosed for lubrication of the use side compressor 62a. In addition, as a use side refrigerant | coolant, from a viewpoint that the refrigerant | coolant advantageous to a high temperature refrigerating cycle is used, the pressure corresponding to saturation gas temperature 65 degreeC is 2.8 Mpa or less at the maximum at a gauge pressure, Preferably, it is 2.0 Mpa. The following refrigerants are preferably used. HFC-134a is a kind of refrigerant having such saturation pressure characteristics. Further, water as an aqueous medium circulates in the aqueous medium circuit 80a.

  In the following description of the configuration, the second usage unit 10a, the hot water storage unit 8a, the hot water heating unit 9a, the liquid refrigerant communication tube 13, and the gas having the same configuration as the heat pump system 200 (see FIG. 7) in the second embodiment. About the structure of the refrigerant | coolant communication pipe | tube 14 and the aqueous medium communication pipe | tube 15a, 16a, the same code | symbol is attached | subjected and description is abbreviate | omitted, and only the structure of the heat-source unit 2, the discharge refrigerant | coolant communication pipe | tube 12, and the 1st utilization unit 4a is demonstrated. I do.

-Heat source unit-
The heat source unit 2 is installed outdoors and is connected to the utilization units 4 a and 10 a via the refrigerant communication pipes 12, 13 and 14, and constitutes a part of the heat source side refrigerant circuit 20.

  The heat source unit 2 mainly includes a heat source side compressor 21, an oil separation mechanism 22, a heat source side switching mechanism 23, a heat source side heat exchanger 24, a heat source side expansion mechanism 25, a suction return pipe 26, and a supercooling. A heat source side accumulator 28, a liquid side closing valve 29, a gas side closing valve 30, and a discharge side closing valve 31.

  Here, the discharge side shut-off valve 31 is formed between the heat source side discharge branch pipe 21d branched from the heat source side discharge pipe 21b connecting the discharge of the heat source side compressor 21 and the heat source side switching mechanism 23 and the gas refrigerant communication pipe 14. It is the valve provided in the connection part.

  The heat source unit 2 is the same as the heat pump system 200 (see FIG. 7) in the second embodiment except for the configuration including the discharge side shut-off valve 31 and the heat source side discharge branch pipe 21d. The same reference numerals are given and the description is omitted.

−Discharge refrigerant communication tube−
The discharge refrigerant communication pipe 12 is connected to the heat source side discharge branch pipe 21d via the discharge side closing valve 31, and the heat source side switching mechanism 23 is on the heat source side in both the heat source side heat radiation operation state and the heat source side evaporation operation state. This is a refrigerant pipe capable of leading the heat source side refrigerant out of the heat source unit 2 from the discharge of the compressor 21.

-First use unit-
The first usage unit 4a is installed indoors, is connected to the heat source unit 2 and the second usage unit 10a via the refrigerant communication pipes 12 and 13, and constitutes a part of the heat source side refrigerant circuit 20. Yes. Moreover, the 1st utilization unit 4a comprises the utilization side refrigerant circuit 40a. Furthermore, the 1st utilization unit 4a is connected to the hot water storage unit 8a and the warm water heating unit 9a via the aqueous medium communication pipes 15a and 16a, and comprises a part of aqueous medium circuit 80a.

  The first usage unit 4a mainly includes a first usage-side heat exchanger 41a, a first usage-side flow rate adjustment valve 42a, a usage-side compressor 62a, a refrigerant-water heat exchanger 65a, and a refrigerant-hydrothermal exchange. It has a side flow rate adjustment valve 66a, a use side accumulator 67a, and a circulation pump 43a.

  Here, the first use side heat exchanger 41a is connected to the gas refrigerant communication pipe 14 like the heat pump system 200 (see FIG. 7) in the second embodiment on the gas side of the flow path through which the heat source side refrigerant flows. Instead of the first use side gas refrigerant pipe 54a, a first use side discharge refrigerant pipe 46a to which the discharge refrigerant communication pipe 12 is connected is connected. The first use side discharge refrigerant pipe 46a allows the flow of the heat source side refrigerant from the discharge refrigerant communication pipe 12 toward the first use side heat exchanger 41a, and the discharge refrigerant communication pipe 12 from the first use side heat exchanger 41a. A first usage-side discharge check valve 49a that prohibits the flow of the heat source side refrigerant toward the first side is provided.

  Note that the usage unit 4a has a configuration excluding the point where the first usage-side discharge refrigerant pipe 46a is connected instead of the first usage-side gas refrigerant pipe 54a. 7), the same reference numerals are given here, and description thereof is omitted.

<Operation>
Next, the operation of the heat pump system 300 will be described.

  As the operation mode of the heat pump system 300, only the hot water supply operation mode in which only the hot water supply operation of the first usage unit 4a (that is, the operation of the hot water storage unit 8a and / or the hot water heating unit 9a) and the cooling operation of the second usage unit 10a are performed. A cooling operation mode for performing the heating operation mode for performing only the heating operation of the second usage unit 10a, a hot water supply / heating operation mode for performing the hot water supply operation of the first usage unit 4a and performing the heating operation of the second usage unit 10a, There is a hot water supply / cooling operation mode in which the hot water supply operation of the first usage unit 4a is performed and the cooling operation of the second usage unit 10a is performed.

  Hereinafter, operations in the five operation modes of the heat pump system 300 will be described.

-Hot water operation mode-
When only the hot water supply operation of the first usage unit 4a is performed, in the heat source side refrigerant circuit 20, the heat source side switching mechanism 23 is in the heat source side evaporation operation state (the state indicated by the broken line of the heat source side switching mechanism 23 in FIG. 13). ), And the suction return expansion valve 26a and the second usage-side flow rate adjustment valve 102a are closed. In the aqueous medium circuit 80a, the aqueous medium switching mechanism 161a is switched to a state in which the aqueous medium is supplied to the hot water storage unit 8a and / or the hot water heating unit 9a.

  In the heat source side refrigerant circuit 20 in such a state, the low pressure heat source side refrigerant in the refrigeration cycle is sucked into the heat source side compressor 21 through the heat source side suction pipe 21c and compressed to a high pressure in the refrigeration cycle, and then the heat source side refrigerant circuit 20 is cooled. It is discharged to the discharge pipe 21b. The high pressure heat source side refrigerant discharged to the heat source side discharge pipe 21b is separated from the refrigerating machine oil in the oil separator 22a. The refrigerating machine oil separated from the heat source side refrigerant in the oil separator 22a is returned to the heat source side suction pipe 21c through the oil return pipe 22b. The high-pressure heat-source-side refrigerant from which the refrigerating machine oil has been separated is sent from the heat-source unit 2 to the discharge refrigerant communication tube 12 through the heat-source-side discharge branch pipe 21d and the discharge-side closing valve 31.

  The high-pressure heat source side refrigerant sent to the discharge refrigerant communication tube 12 is sent to the first usage unit 4a. The high-pressure heat-source-side refrigerant sent to the first usage unit 4a is sent to the first usage-side heat exchanger 41a through the first usage-side discharge refrigerant tube 46a and the first usage-side discharge check valve 49a. The high-pressure heat-source-side refrigerant sent to the first usage-side heat exchanger 41a exchanges heat with the low-pressure usage-side refrigerant in the refrigeration cycle circulating in the usage-side refrigerant circuit 40a in the first usage-side heat exchanger 41a. To dissipate heat. The high-pressure heat-source-side refrigerant radiated in the first usage-side heat exchanger 41a is sent from the first usage unit 4a to the liquid refrigerant communication tube 13 through the first usage-side flow rate adjustment valve 42a and the first usage-side liquid refrigerant tube 45a. It is done.

  The heat source side refrigerant sent to the liquid refrigerant communication tube 13 is sent to the heat source unit 2. The heat source side refrigerant sent to the heat source unit 2 is sent to the supercooler 27 through the liquid side shut-off valve 29. The heat source side refrigerant sent to the subcooler 27 is sent to the heat source side expansion valve 25 without performing heat exchange because the heat source side refrigerant does not flow through the suction return pipe 26. The heat source side refrigerant sent to the heat source side expansion valve 25 is depressurized by the heat source side expansion valve 25 to be in a low-pressure gas-liquid two-phase state, and sent to the heat source side heat exchanger 24 through the heat source side liquid refrigerant tube 24a. It is done. The low-pressure refrigerant sent to the heat source side heat exchanger 24 evaporates by exchanging heat with outdoor air supplied by the heat source side fan 32 in the heat source side heat exchanger 24. The low-pressure heat source side refrigerant evaporated in the heat source side heat exchanger 24 is sent to the heat source side accumulator 28 through the first heat source side gas refrigerant tube 23a and the heat source side switching mechanism 23. The low-pressure heat source side refrigerant sent to the heat source side accumulator 28 is again sucked into the heat source side compressor 21 through the heat source side suction pipe 21c.

  On the other hand, in the usage-side refrigerant circuit 40a, the low-pressure usage-side refrigerant in the refrigeration cycle circulating in the usage-side refrigerant circuit 40a is heated and evaporated by the heat radiation of the heat-source-side refrigerant in the first usage-side heat exchanger 41a. The low-pressure usage-side refrigerant evaporated in the first usage-side heat exchanger 41a is sent to the usage-side accumulator 67a through the second cascade-side gas refrigerant tube 69a. The low-pressure use-side refrigerant sent to the use-side accumulator 67a is sucked into the use-side compressor 62a through the cascade-side suction pipe 71a, compressed to a high pressure in the refrigeration cycle, and then discharged to the cascade-side discharge pipe 70a. . The high-pressure use-side refrigerant discharged to the cascade-side discharge pipe 70a is sent to the refrigerant-water heat exchanger 65a through the first cascade-side gas refrigerant pipe 72a. The high-pressure usage-side refrigerant sent to the refrigerant-water heat exchanger 65a radiates heat by exchanging heat with the aqueous medium circulating in the aqueous medium circuit 80a by the circulation pump 43a in the refrigerant-water heat exchanger 65a. The high-pressure use-side refrigerant that has radiated heat in the refrigerant-water heat exchanger 65a is decompressed in the refrigerant-water heat exchange side flow rate adjustment valve 66a to become a low-pressure gas-liquid two-phase state, and through the cascade-side liquid refrigerant pipe 68a. Again, it is sent to the 1st utilization side heat exchanger 41a.

  In the aqueous medium circuit 80a, the aqueous medium circulating in the aqueous medium circuit 80a is heated by the heat radiation of the use-side refrigerant in the refrigerant-water heat exchanger 65a. The aqueous medium heated in the refrigerant-water heat exchanger 65a is drawn into the circulation pump 43a through the first usage-side water outlet pipe 48a, and after being pressurized, is sent from the first usage unit 4a to the aqueous medium communication pipe 16a. It is done. The aqueous medium sent to the aqueous medium communication pipe 16a is sent to the hot water storage unit 8a and / or the hot water heating unit 9a through the aqueous medium side switching mechanism 161a. The aqueous medium sent to the hot water storage unit 8a exchanges heat with the aqueous medium in the hot water storage tank 81a in the heat exchange coil 82a to radiate heat, thereby heating the aqueous medium in the hot water storage tank 81a. The aqueous medium sent to the hot water heating unit 9a dissipates heat in the heat exchange panel 91a, thereby heating the indoor wall or the like or heating the indoor floor.

  In this manner, the operation in the hot water supply operation mode in which only the hot water supply operation of the first usage unit 4a is performed is performed.

-Cooling operation mode-
When only the cooling operation of the second usage unit 10a is performed, in the heat source side refrigerant circuit 20, the heat source side switching mechanism 23 is in the heat source side heat dissipation operation state (the state shown by the solid line of the heat source side switching mechanism 23 in FIG. 13). ) And the first usage-side flow rate adjustment valve 42a is closed.

  In the heat source side refrigerant circuit 20 in such a state, the low pressure heat source side refrigerant in the refrigeration cycle is sucked into the heat source side compressor 21 through the heat source side suction pipe 21c and compressed to a high pressure in the refrigeration cycle, and then the heat source side refrigerant circuit 20 is cooled. It is discharged to the discharge pipe 21b. The high pressure heat source side refrigerant discharged to the heat source side discharge pipe 21b is separated from the refrigerating machine oil in the oil separator 22a. The refrigerating machine oil separated from the heat source side refrigerant in the oil separator 22a is returned to the heat source side suction pipe 21c through the oil return pipe 22b. The high-pressure heat-source-side refrigerant from which the refrigeration oil is separated is sent to the heat-source-side heat exchanger 24 through the heat-source-side switching mechanism 23 and the first heat-source-side gas refrigerant tube 23a. The high-pressure heat-source-side refrigerant sent to the heat-source-side heat exchanger 24 radiates heat by exchanging heat with outdoor air supplied by the heat-source-side fan 32 in the heat source-side heat exchanger 24. The high-pressure heat-source-side refrigerant that has radiated heat in the heat-source-side heat exchanger is sent to the supercooler 27 through the heat source-side expansion valve 25. The heat-source-side refrigerant sent to the subcooler 27 is cooled so as to be in a supercooled state by exchanging heat with the heat-source-side refrigerant branched from the heat source-side liquid refrigerant tube 24a to the suction return tube 26. The heat source side refrigerant flowing through the suction return pipe 26 is returned to the heat source side suction pipe 21c. The heat source side refrigerant cooled in the subcooler 27 is sent from the heat source unit 2 to the liquid refrigerant communication tube 13 through the heat source side liquid refrigerant tube 24a and the liquid side shut-off valve 29.

  The high-pressure heat-source-side refrigerant sent to the liquid refrigerant communication tube 13 is sent to the second usage unit 10a. The high-pressure heat-source-side refrigerant sent to the second usage unit 10a is sent to the second usage-side flow rate adjustment valve 102a. The high-pressure heat-source-side refrigerant sent to the second usage-side flow rate adjustment valve 102a is depressurized by the second usage-side flow rate adjustment valve 102a to become a low-pressure gas-liquid two-phase state, and the second usage-side liquid refrigerant tube 103a. To the second usage side heat exchanger 101a. The low-pressure heat source side refrigerant sent to the second usage side heat exchanger 101a evaporates by exchanging heat with the air medium supplied by the usage side fan 105a in the second usage side heat exchanger 101a. Cool the room. The low-pressure heat-source-side refrigerant evaporated in the second usage-side heat exchanger 101a is sent from the second usage unit 10a to the gas refrigerant communication tube 14 through the second usage-side gas refrigerant tube 104a.

  The low-pressure heat source side refrigerant sent to the gas refrigerant communication tube 14 is sent to the heat source unit 2. The low-pressure heat source side refrigerant sent to the heat source unit 2 is sent to the heat source side accumulator 28 through the gas side shut-off valve 30, the second heat source side gas refrigerant tube 23b, and the heat source side switching mechanism 23. The low-pressure heat source side refrigerant sent to the heat source side accumulator 28 is again sucked into the heat source side compressor 21 through the heat source side suction pipe 21c.

  In this manner, the operation in the cooling operation mode in which only the cooling operation of the second usage unit 10a is performed is performed.

−Heating operation mode−
When only the heating operation of the second usage unit 10a is performed, in the heat source side refrigerant circuit 20, the heat source side switching mechanism 23 is in the heat source side heat radiation operation state (the state indicated by the broken line of the heat source side switching mechanism 23 in FIG. 13). And the suction return expansion valve 26a and the first usage-side flow rate adjustment valve 42a are closed.

  In the heat source side refrigerant circuit 20 in such a state, the low pressure heat source side refrigerant in the refrigeration cycle is sucked into the heat source side compressor 21 through the heat source side suction pipe 21c and compressed to a high pressure in the refrigeration cycle, and then the heat source side refrigerant circuit 20 is cooled. It is discharged to the discharge pipe 21b. The high pressure heat source side refrigerant discharged to the heat source side discharge pipe 21b is separated from the refrigerating machine oil in the oil separator 22a. The refrigerating machine oil separated from the heat source side refrigerant in the oil separator 22a is returned to the heat source side suction pipe 21c through the oil return pipe 22b. The high-pressure heat source side refrigerant from which the refrigerating machine oil is separated is sent from the heat source unit 2 to the gas refrigerant communication tube 14 through the heat source side switching mechanism 23, the second heat source side gas refrigerant tube 23b, and the gas side shut-off valve 30.

  The high-pressure heat source-side refrigerant sent to the gas refrigerant communication tube 14 is sent to the second usage unit 10a. The high-pressure heat-source-side refrigerant sent to the second usage unit 10a is sent to the second usage-side heat exchanger 101a through the second usage-side gas refrigerant tube 104a. The high-pressure heat-source-side refrigerant sent to the second usage-side heat exchanger 101a radiates heat by exchanging heat with the air medium supplied by the usage-side fan 105a in the second usage-side heat exchanger 101a. , Heating the room. The high-pressure heat-source-side refrigerant radiated in the second usage-side heat exchanger 101a is sent from the second usage unit 10a to the liquid refrigerant communication tube 13 through the second usage-side flow rate adjustment valve 102a and the second usage-side liquid refrigerant tube 103a. It is done.

  The heat source side refrigerant sent to the liquid refrigerant communication tube 13 is sent to the heat source unit 2. The heat source side refrigerant sent to the heat source unit 2 is sent to the supercooler 27 through the liquid side shut-off valve 29. The heat source side refrigerant sent to the subcooler 27 is sent to the heat source side expansion valve 25 without performing heat exchange because the heat source side refrigerant does not flow through the suction return pipe 26. The heat source side refrigerant sent to the heat source side expansion valve 25 is depressurized by the heat source side expansion valve 25 to be in a low-pressure gas-liquid two-phase state, and sent to the heat source side heat exchanger 24 through the heat source side liquid refrigerant tube 24a. It is done. The low-pressure refrigerant sent to the heat source side heat exchanger 24 evaporates by exchanging heat with outdoor air supplied by the heat source side fan 32 in the heat source side heat exchanger 24. The low-pressure heat source side refrigerant evaporated in the heat source side heat exchanger 24 is sent to the heat source side accumulator 28 through the first heat source side gas refrigerant tube 23a and the heat source side switching mechanism 23. The low-pressure heat source side refrigerant sent to the heat source side accumulator 28 is again sucked into the heat source side compressor 21 through the heat source side suction pipe 21c.

  Thus, the operation | movement in the heating operation mode which performs only the heating operation of the 2nd utilization unit 10a is performed.

-Hot water heating / heating mode-
When the hot water supply operation of the first usage unit 4a is performed and the heating operation of the second usage unit 10a is performed, in the heat source side refrigerant circuit 20, the heat source side switching mechanism 23 is in the heat source side evaporation operation state (the heat source side in FIG. 13). (The state indicated by the broken line of the switching mechanism 23), and the suction return expansion valve 26a is closed. In the aqueous medium circuit 80a, the aqueous medium switching mechanism 161a is switched to a state in which the aqueous medium is supplied to the hot water storage unit 8a and / or the hot water heating unit 9a.

  In the heat source side refrigerant circuit 20 in such a state, the low pressure heat source side refrigerant in the refrigeration cycle is sucked into the heat source side compressor 21 through the heat source side suction pipe 21c and compressed to a high pressure in the refrigeration cycle, and then the heat source side refrigerant circuit 20 is cooled. It is discharged to the discharge pipe 21b. The high pressure heat source side refrigerant discharged to the heat source side discharge pipe 21b is separated from the refrigerating machine oil in the oil separator 22a. The refrigerating machine oil separated from the heat source side refrigerant in the oil separator 22a is returned to the heat source side suction pipe 21c through the oil return pipe 22b. A part of the high-pressure heat source side refrigerant from which the refrigerating machine oil is separated is sent from the heat source unit 2 to the discharge refrigerant communication pipe 12 through the heat source side discharge branch pipe 21d and the discharge side shut-off valve 31, and the rest is used as the heat source. It is sent from the heat source unit 2 to the gas refrigerant communication pipe 14 through the side switching mechanism 23, the second heat source side gas refrigerant pipe 23 b and the gas side shut-off valve 30.

  The high-pressure heat source-side refrigerant sent to the gas refrigerant communication tube 14 is sent to the second usage unit 10a. The high-pressure heat-source-side refrigerant sent to the second usage unit 10a is sent to the second usage-side heat exchanger 101a through the second usage-side gas refrigerant tube 104a. The high-pressure heat-source-side refrigerant sent to the second usage-side heat exchanger 101a radiates heat by exchanging heat with the air medium supplied by the usage-side fan 105a in the second usage-side heat exchanger 101a. , Heating the room. The high-pressure heat-source-side refrigerant radiated in the second usage-side heat exchanger 101a is sent from the second usage unit 10a to the liquid refrigerant communication tube 13 through the second usage-side flow rate adjustment valve 102a and the second usage-side liquid refrigerant tube 103a. It is done.

  The high-pressure heat source side refrigerant sent to the discharge refrigerant communication tube 12 is sent to the first usage unit 4a. The high-pressure heat-source-side refrigerant sent to the first usage unit 4a is sent to the first usage-side heat exchanger 41a through the first usage-side discharge refrigerant tube 46a and the first usage-side discharge check valve 49a. The high-pressure heat-source-side refrigerant sent to the first usage-side heat exchanger 41a exchanges heat with the low-pressure usage-side refrigerant in the refrigeration cycle circulating in the usage-side refrigerant circuit 40a in the first usage-side heat exchanger 41a. To dissipate heat. The high-pressure heat-source-side refrigerant radiated in the first usage-side heat exchanger 41a is sent from the first usage unit 4a to the liquid refrigerant communication tube 13 through the first usage-side flow rate adjustment valve 42a and the first usage-side liquid refrigerant tube 45a. It is done.

  The heat source side refrigerant sent from the second usage unit 10a and the first usage unit 4a to the liquid refrigerant communication tube 13 merges in the liquid refrigerant communication tube 13 and is sent to the heat source unit 2. The heat source side refrigerant sent to the heat source unit 2 is sent to the supercooler 27 through the liquid side shut-off valve 29. The heat source side refrigerant sent to the subcooler 27 is sent to the heat source side expansion valve 25 without performing heat exchange because the heat source side refrigerant does not flow through the suction return pipe 26. The heat source side refrigerant sent to the heat source side expansion valve 25 is depressurized by the heat source side expansion valve 25 to be in a low-pressure gas-liquid two-phase state, and sent to the heat source side heat exchanger 24 through the heat source side liquid refrigerant tube 24a. It is done. The low-pressure refrigerant sent to the heat source side heat exchanger 24 evaporates by exchanging heat with outdoor air supplied by the heat source side fan 32 in the heat source side heat exchanger 24. The low-pressure heat source side refrigerant evaporated in the heat source side heat exchanger 24 is sent to the heat source side accumulator 28 through the first heat source side gas refrigerant tube 23a and the heat source side switching mechanism 23. The low-pressure heat source side refrigerant sent to the heat source side accumulator 28 is again sucked into the heat source side compressor 21 through the heat source side suction pipe 21c.

  On the other hand, in the usage-side refrigerant circuit 40a, the low-pressure usage-side refrigerant in the refrigeration cycle circulating in the usage-side refrigerant circuit 40a is heated and evaporated by the heat radiation of the heat-source-side refrigerant in the first usage-side heat exchanger 41a. The low-pressure usage-side refrigerant evaporated in the first usage-side heat exchanger 41a is sent to the usage-side accumulator 67a through the second cascade-side gas refrigerant tube 69a. The low-pressure use-side refrigerant sent to the use-side accumulator 67a is sucked into the use-side compressor 62a through the cascade-side suction pipe 71a, compressed to a high pressure in the refrigeration cycle, and then discharged to the cascade-side discharge pipe 70a. . The high-pressure use-side refrigerant discharged to the cascade-side discharge pipe 70a is sent to the refrigerant-water heat exchanger 65a through the first cascade-side gas refrigerant pipe 72a. The high-pressure usage-side refrigerant sent to the refrigerant-water heat exchanger 65a radiates heat by exchanging heat with the aqueous medium circulating in the aqueous medium circuit 80a by the circulation pump 43a in the refrigerant-water heat exchanger 65a. The high-pressure use-side refrigerant that has radiated heat in the refrigerant-water heat exchanger 65a is decompressed in the refrigerant-water heat exchange side flow rate adjustment valve 66a to become a low-pressure gas-liquid two-phase state, and through the cascade-side liquid refrigerant pipe 68a. Again, it is sent to the 1st utilization side heat exchanger 41a.

  In the aqueous medium circuit 80a, the aqueous medium circulating in the aqueous medium circuit 80a is heated by the heat radiation of the use-side refrigerant in the refrigerant-water heat exchanger 65a. The aqueous medium heated in the refrigerant-water heat exchanger 65a is drawn into the circulation pump 43a through the first usage-side water outlet pipe 48a, and after being pressurized, is sent from the first usage unit 4a to the aqueous medium communication pipe 16a. It is done. The aqueous medium sent to the aqueous medium communication pipe 16a is sent to the hot water storage unit 8a and / or the hot water heating unit 9a through the aqueous medium side switching mechanism 161a. The aqueous medium sent to the hot water storage unit 8a exchanges heat with the aqueous medium in the hot water storage tank 81a in the heat exchange coil 82a to radiate heat, thereby heating the aqueous medium in the hot water storage tank 81a. The aqueous medium sent to the hot water heating unit 9a dissipates heat in the heat exchange panel 91a, thereby heating the indoor wall or the like or heating the indoor floor.

  Thus, the operation in the hot water supply / heating operation mode in which the hot water supply operation of the first usage unit 4a is performed and the heating operation of the second usage unit 10a is performed is performed.

-Hot water supply / cooling operation mode-
When the hot water supply operation of the first usage unit 4a is performed and the cooling operation of the second usage unit 10a is performed, in the heat source side refrigerant circuit 20, the heat source side switching mechanism 23 is in the heat source side heat radiation operation state (the heat source side in FIG. 13). The switching mechanism 23 is switched to the state indicated by the solid line). In the aqueous medium circuit 80a, the aqueous medium switching mechanism 161a is switched to a state of supplying the aqueous medium to the hot water storage unit 8a.

  In the heat source side refrigerant circuit 20 in such a state, the low pressure heat source side refrigerant in the refrigeration cycle is sucked into the heat source side compressor 21 through the heat source side suction pipe 21c and compressed to a high pressure in the refrigeration cycle, and then discharged from the heat source side. It is discharged to the tube 21b. The high pressure heat source side refrigerant discharged to the heat source side discharge pipe 21b is separated from the refrigerating machine oil in the oil separator 22a. The refrigerating machine oil separated from the heat source side refrigerant in the oil separator 22a is returned to the heat source side suction pipe 21c through the oil return pipe 22b. A part of the high-pressure heat source side refrigerant from which the refrigerating machine oil is separated is sent from the heat source unit 2 to the discharge refrigerant communication pipe 12 through the heat source side discharge branch pipe 21d and the discharge side shut-off valve 31, and the rest is used as the heat source. It is sent to the heat source side heat exchanger 24 through the side switching mechanism 23 and the first heat source side gas refrigerant tube 23a. The high-pressure heat-source-side refrigerant sent to the heat-source-side heat exchanger 24 radiates heat by exchanging heat with outdoor air supplied by the heat-source-side fan 32 in the heat source-side heat exchanger 24. The high-pressure heat-source-side refrigerant that has radiated heat in the heat-source-side heat exchanger is sent to the supercooler 27 through the heat source-side expansion valve 25. The heat-source-side refrigerant sent to the subcooler 27 is cooled so as to be in a supercooled state by exchanging heat with the heat-source-side refrigerant branched from the heat source-side liquid refrigerant tube 24a to the suction return tube 26. The heat source side refrigerant flowing through the suction return pipe 26 is returned to the heat source side suction pipe 21c. The heat source side refrigerant cooled in the subcooler 27 is sent from the heat source unit 2 to the liquid refrigerant communication tube 13 through the heat source side liquid refrigerant tube 24a and the liquid side shut-off valve 29.

  The high-pressure heat source side refrigerant sent to the discharge refrigerant communication tube 12 is sent to the first usage unit 4a. The high-pressure heat-source-side refrigerant sent to the first usage unit 4a is sent to the first usage-side heat exchanger 41a through the first usage-side discharge refrigerant tube 46a and the first usage-side discharge check valve 49a. The high-pressure heat-source-side refrigerant sent to the first usage-side heat exchanger 41a exchanges heat with the low-pressure usage-side refrigerant in the refrigeration cycle circulating in the usage-side refrigerant circuit 40a in the first usage-side heat exchanger 41a. To dissipate heat. The high-pressure heat-source-side refrigerant radiated in the first usage-side heat exchanger 41a is sent from the first usage unit 4a to the liquid refrigerant communication tube 13 through the first usage-side flow rate adjustment valve 42a and the first usage-side liquid refrigerant tube 45a. It is done.

  The heat source side refrigerant sent from the heat source unit 2 and the first usage unit 4a to the liquid refrigerant communication tube 13 merges in the liquid refrigerant communication tube 13 and is sent to the second usage unit 10a. The heat-source-side refrigerant sent to the second usage unit 10a is sent to the second usage-side flow rate adjustment valve 102a. The heat-source-side refrigerant sent to the second usage-side flow rate adjustment valve 102a is depressurized by the second usage-side flow rate adjustment valve 102a to be in a low-pressure gas-liquid two-phase state, and is passed through the second usage-side liquid refrigerant tube 103a. 2 is sent to the use side heat exchanger 101a. The low-pressure heat source side refrigerant sent to the second usage side heat exchanger 101a evaporates by exchanging heat with the air medium supplied by the usage side fan 105a in the second usage side heat exchanger 101a. Cool the room. The low-pressure heat-source-side refrigerant evaporated in the second usage-side heat exchanger 101a is sent from the second usage unit 10a to the gas refrigerant communication tube 14 through the second usage-side gas refrigerant tube 104a.

  The low-pressure heat source side refrigerant sent to the gas refrigerant communication tube 14 is sent to the heat source unit 2. The low-pressure heat source side refrigerant sent to the heat source unit 2 is sent to the heat source side accumulator 28 through the gas side shut-off valve 30, the second heat source side gas refrigerant tube 23b, and the heat source side switching mechanism 23. The low-pressure heat source side refrigerant sent to the heat source side accumulator 28 is again sucked into the heat source side compressor 21 through the heat source side suction pipe 21c.

  On the other hand, in the usage-side refrigerant circuit 40a, the low-pressure usage-side refrigerant in the refrigeration cycle circulating in the usage-side refrigerant circuit 40a is heated and evaporated by the heat radiation of the heat-source-side refrigerant in the first usage-side heat exchanger 41a. The low-pressure usage-side refrigerant evaporated in the first usage-side heat exchanger 41a is sent to the usage-side accumulator 67a through the second cascade-side gas refrigerant tube 69a. The low-pressure use-side refrigerant sent to the use-side accumulator 67a is sucked into the use-side compressor 62a through the cascade-side suction pipe 71a, compressed to a high pressure in the refrigeration cycle, and then discharged to the cascade-side discharge pipe 70a. . The high-pressure use-side refrigerant discharged to the cascade-side discharge pipe 70a is sent to the refrigerant-water heat exchanger 65a through the first cascade-side gas refrigerant pipe 72a. The high-pressure usage-side refrigerant sent to the refrigerant-water heat exchanger 65a radiates heat by exchanging heat with the aqueous medium circulating in the aqueous medium circuit 80a by the circulation pump 43a in the refrigerant-water heat exchanger 65a. The high-pressure use-side refrigerant that has radiated heat in the refrigerant-water heat exchanger 65a is decompressed in the refrigerant-water heat exchange side flow rate adjustment valve 66a to become a low-pressure gas-liquid two-phase state, and through the cascade-side liquid refrigerant pipe 68a. Again, it is sent to the 1st utilization side heat exchanger 41a.

  In the aqueous medium circuit 80a, the aqueous medium circulating in the aqueous medium circuit 80a is heated by the heat radiation of the use-side refrigerant in the refrigerant-water heat exchanger 65a. The aqueous medium heated in the refrigerant-water heat exchanger 65a is drawn into the circulation pump 43a through the first usage-side water outlet pipe 48a, and after being pressurized, is sent from the first usage unit 4a to the aqueous medium communication pipe 16a. It is done. The aqueous medium sent to the aqueous medium communication pipe 16a is sent to the hot water storage unit 8a through the aqueous medium side switching mechanism 161a. The aqueous medium sent to the hot water storage unit 8a exchanges heat with the aqueous medium in the hot water storage tank 81a in the heat exchange coil 82a to radiate heat, thereby heating the aqueous medium in the hot water storage tank 81a.

  Thus, the operation in the hot water supply / cooling operation mode in which the hot water supply operation of the first usage unit 4a is performed and the cooling operation of the second usage unit 10a is performed is performed.

  Here, in the configuration of the heat pump system 300 in which the first use unit 4a for hot water supply operation and the second use unit 10a for air conditioning operation are connected to the heat source unit 2 so that the hot water supply and cooling operation can be performed, the second Similar to the heat pump system 200 (see FIG. 7) in the embodiment, the discharge saturation temperature control of the refrigerant circuits 20 and 40a, the supercooling degree control of the outlets of the heat exchangers 41a and 65a, and the aqueous medium circulating in the aqueous medium circuit 80a Flow control and activation control of each circuit 20, 40a, 80a.

  Thereby, in this heat pump system 300, not only the effect similar to the heat pump system 200 in 2nd Embodiment can be acquired, but an aqueous medium is heated by the 1st utilization side heat exchanger 41a and the utilization side refrigerant circuit 40a. The cooling heat obtained by the heat source side refrigerant by performing the operation and heating the aqueous medium can be used for the operation of cooling the air medium by the evaporation of the heat source side refrigerant in the second usage side heat exchanger 101a. Therefore, for example, the aqueous medium heated by the first usage-side heat exchanger 41a and the usage-side refrigerant circuit 40a is used for hot water supply, and the air medium cooled in the second usage-side heat exchanger 101a is used indoors. The cooling heat obtained by the heat-source-side refrigerant by heating the aqueous medium, such as for cooling It can be, thereby, it is possible to achieve energy saving.

(1) Modification 1
As in the heat pump system 300 (see FIG. 13), the first usage unit 4a for hot water supply operation and the second usage unit 10a for air conditioning operation are connected to the heat source unit 2 so as to enable hot water supply and cooling operation. Also in the configuration, as in the case of the heat pump system 200 (see FIG. 7) in the first modification of the second embodiment, when the supply of an aqueous medium having a wide temperature is required, the utilization side compressor 62a is used for discharging. The use side inlet / outlet pressure difference ΔP2 which is the pressure difference between the use side discharge pressure Pd2 which is the pressure of the side refrigerant and the use side suction pressure Pd2 which is the pressure of the use side refrigerant in the suction of the use side compressor 62a becomes very small, Since the usage-side refrigerant circuit 40a is required to operate at a low load, the refrigeration cycle of the usage-side refrigerant circuit 40a can be achieved only by controlling the capacity of the usage-side compressor 62a. There is a possibility which can not be controlled, also insufficient lubrication even cause that occurs bad circulation of the refrigerating machine oil in the usage-side compressor in 62a.

  Therefore, in the heat pump system 300, the use side low-load operation control (see FIG. 3) similar to the heat pump system 200 (see FIG. 7) in the second embodiment is performed.

  Thereby, even when the use side inlet / outlet pressure difference ΔP2 is very small, the flow rate of the heat source side refrigerant flowing into the first use side heat exchanger 41a is reduced, and the heat in the first use side heat exchanger 41a is reduced. The use side refrigerant circuit 40a can be easily operated even under a low load condition by suppressing the exchange capacity so that the use side inlet / outlet pressure difference ΔP2 is increased. be able to.

(2) Modification 2
In the above-described heat pump system 300 (see FIG. 13), as shown in FIG. 14, the refrigerant-water heat exchanger 65a functions as a radiator for the usage-side refrigerant and the first usage-side heat exchanger 41a is used as the usage-side refrigerant. Use side heat radiation operating state to function as an evaporator of the use side and the use side to cause the refrigerant-water heat exchanger 65a to function as an evaporator of the use side refrigerant and to function the first use side heat exchanger 41a as a radiator of the use side refrigerant A first usage side switching mechanism 64a (similar to the first usage side switching mechanism 64a provided in the heat pump system 200 in the second embodiment) capable of switching between the evaporation operation states is further provided in the usage side refrigerant circuit 40a; The first usage unit 4a is further connected to the gas refrigerant communication tube 14, and the first usage-side heat exchanger 41a is introduced from the discharge refrigerant communication tube 12 as a heat source. Switching between an aqueous medium heating operation state that functions as a refrigerant radiator and an aqueous medium cooling operation state that causes the first use side heat exchanger 41a to function as an evaporator of a heat source side refrigerant introduced from the liquid refrigerant communication tube 13 is possible. A possible second usage side switching mechanism 53a may be further provided.

  Here, the 1st utilization side gas refrigerant pipe 54a is connected with the gas side of the flow path through which the heat source side refrigerant of the 1st utilization side heat exchanger 41a flows along with the 1st utilization side discharge refrigerant pipe 46a. The first refrigerant gas refrigerant pipe 54a is connected to the gas refrigerant communication pipe 14. The second usage-side switching mechanism 53a includes a first usage-side discharge opening / closing valve 55a (here, the first usage-side discharge check valve 49a is omitted) provided in the first usage-side discharge refrigerant pipe 46a, A first use side gas on / off valve 56a provided in the side gas refrigerant pipe 54a, by opening the first use side discharge on / off valve 55a and closing the first use side gas on / off valve 56a. The aqueous medium heating operation state is set, the first usage side discharge on / off valve 55a is closed, and the first usage side gas on / off valve 56a is opened to enter the aqueous medium cooling operation state. Each of the first usage-side discharge on-off valve 55a and the first usage-side gas on-off valve 56a is an electromagnetic valve that can be controlled to open and close. The second usage side switching mechanism 53a may be constituted by a three-way valve or the like.

  In the heat pump system 300 having such a configuration, when it is determined that defrosting of the heat source side heat exchanger 24 is necessary by operations in the hot water supply operation mode, the heating operation mode, and the hot water supply heating operation mode, the heat source side By setting the switching mechanism 23 to the heat source side heat radiation operation state, the heat source side heat exchanger 24 functions as a heat source side refrigerant radiator and the second usage side heat exchanger 101a functions as a heat source side refrigerant evaporator. In addition, the refrigerant-water heat exchanger 65a functions as an evaporator of the usage-side refrigerant by setting the first usage-side switching mechanism 64a to the usage-side evaporation operation state, and the first usage-side heat exchanger 41a is used on the usage side. A defrosting operation that functions as a radiator of the refrigerant can be performed.

  Hereinafter, the operation in the defrosting operation will be described with reference to FIG.

  First, it is determined whether or not a predetermined defrosting operation start condition is satisfied (that is, whether or not the heat source side heat exchanger 24 needs to be defrosted) (step S21). Here, whether or not the defrosting operation start condition is satisfied depends on whether or not the defrosting time interval Δtdf (that is, the accumulated operation time from the end of the previous defrosting operation) has reached a predetermined defrosting time interval set value Δtdfs. judge.

  And when it determines with satisfy | filling the defrost operation start conditions, the following defrost operations are started (step S22).

  When starting the defrosting operation, in the heat source side refrigerant circuit 20, the heat source side switching mechanism 23 is switched to the heat source side heat radiation operation state (the state indicated by the solid line of the heat source side switching mechanism 23 in FIG. 14). In the usage-side refrigerant circuit 40a, the first usage-side switching mechanism 64a is switched to the usage-side evaporation operation state (the state indicated by the broken line of the first usage-side switching mechanism 64a in FIG. 14), and the second usage-side switching mechanism. 53a is switched to an aqueous medium cooling operation state (that is, a state where the first use side discharge on / off valve 55a is closed and the first use side gas on / off valve 56a is opened), and the suction return expansion valve 26a is closed. It becomes a state.

  When the heat source side switching mechanism 23 is set to the heat source side heat radiation operation state and the first usage side switching mechanism 64a is switched to the usage side evaporation operation state, the refrigerant in each refrigerant circuit 20, 40a Is generated, and a noise (that is, a pressure equalization sound) at the time of pressure equalization of the refrigerant in each of the refrigerant circuits 20 and 40a is generated. However, it is possible to prevent such pressure equalization sound from becoming excessive. preferable.

  Therefore, in the heat pump system 300, when the defrosting operation is started, after the heat source side switching mechanism 23 is set to the heat source side heat radiation operation state, the first usage side switching mechanism 64a is set to the usage side evaporation operation state. The refrigerant in both refrigerant circuits 20 and 40a is prevented from being equalized simultaneously. Thereby, it is possible to prevent excessive pressure equalization when performing the defrosting operation.

  In the heat pump system 300, when the first usage-side switching mechanism 64a is set to the usage-side evaporation operation state, the usage-side compressor 62a is stopped and the first usage-side switching mechanism 64a is operated to the usage-side evaporation operation. Since it is made into a state, it can prevent that the equalization sound in the utilization side refrigerant circuit 40a becomes large.

  Further, in this heat pump system 300, when the use side compressor 62a is stopped, the refrigerant-water heat exchange side flow rate adjustment valve 66a remains open (more specifically, fully open). Since the use side compressor 62a is stopped, the pressure equalization in the use side refrigerant circuit 40a can be performed quickly.

  In the heat source side refrigerant circuit 20 in such a state, the low pressure heat source side refrigerant in the refrigeration cycle is sucked into the heat source side compressor 21 through the heat source side suction pipe 21c and compressed to a high pressure in the refrigeration cycle, and then the heat source side refrigerant circuit 20 is cooled. It is discharged to the discharge pipe 21b. The high pressure heat source side refrigerant discharged to the heat source side discharge pipe 21b is separated from the refrigerating machine oil in the oil separator 22a. The refrigerating machine oil separated from the heat source side refrigerant in the oil separator 22a is returned to the heat source side suction pipe 21c through the oil return pipe 22b. The high-pressure heat-source-side refrigerant from which the refrigeration oil is separated is sent to the heat-source-side heat exchanger 24 through the heat-source-side switching mechanism 23 and the first heat-source-side gas refrigerant tube 23a. The high-pressure heat-source-side refrigerant sent to the heat-source-side heat exchanger 24 radiates heat by exchanging heat with ice attached to the heat-source-side heat exchanger 24 in the heat-source-side heat exchanger 24. The high-pressure heat-source-side refrigerant that has radiated heat in the heat-source-side heat exchanger is sent to the supercooler 27 through the heat source-side expansion valve 25. Since the heat source side refrigerant sent to the subcooler 27 does not flow through the suction return pipe 26, the heat source unit refrigerant passes through the heat source side liquid refrigerant tube 24a and the liquid side shut-off valve 29 without performing heat exchange. 2 to the liquid refrigerant communication tube 13.

  The heat-source-side refrigerant sent to the liquid refrigerant communication tube 13 branches in the liquid refrigerant communication tube 13 and is sent to the first usage unit 4a and the second usage unit 10a.

  The heat-source-side refrigerant sent to the second usage unit 10a is sent to the second usage-side flow rate adjustment valve 102a. The heat-source-side refrigerant sent to the second usage-side flow rate adjustment valve 102a is depressurized by the second usage-side flow rate adjustment valve 102a to be in a low-pressure gas-liquid two-phase state, and through the second usage-side liquid refrigerant tube 103a, It is sent to the second usage side heat exchanger 101a. The low-pressure heat-source-side refrigerant sent to the second usage-side heat exchanger 101a evaporates by exchanging heat with the air medium supplied by the usage-side fan 105a in the second usage-side heat exchanger 101a. The low-pressure heat-source-side refrigerant evaporated in the second usage-side heat exchanger 101a is sent from the second usage unit 10a to the gas refrigerant communication tube 14 through the second usage-side gas refrigerant tube 104a.

  The heat-source-side refrigerant sent to the first usage unit 4a is sent to the first usage-side flow rate adjustment valve 42a. The heat-source-side refrigerant sent to the first usage-side flow rate adjustment valve 42a is depressurized in the first usage-side flow rate adjustment valve 42a to become a low-pressure gas-liquid two-phase state, and through the first usage-side liquid refrigerant tube 45a, It is sent to the first usage side heat exchanger 41a. The low-pressure heat-source-side refrigerant sent to the first usage-side heat exchanger 41a exchanges heat with the high-pressure usage-side refrigerant in the refrigeration cycle circulating in the usage-side refrigerant circuit 40a in the first usage-side heat exchanger 41a. Evaporate. The low-pressure heat source side refrigerant evaporated in the first usage-side heat exchanger 41a is the low-pressure heat source-side refrigerant evaporated in the first usage-side heat exchanger 41a, and the first usage side constituting the second usage-side switching mechanism 53a. The gas is sent from the first usage unit 4a to the gas refrigerant communication pipe 14 through the gas on-off valve 56a and the first usage-side gas refrigerant pipe 54a.

  The heat source side refrigerant sent from the second usage unit 10a and the first usage unit 4a to the gas refrigerant communication tube 14 merges in the gas refrigerant communication tube 14 and is sent to the heat source unit 2. The low-pressure heat source side refrigerant sent to the heat source unit 2 is sent to the heat source side accumulator 28 through the gas side shut-off valve 30, the second heat source side gas refrigerant tube 23b, and the heat source side switching mechanism 23. The low-pressure heat source side refrigerant sent to the heat source side accumulator 28 is again sucked into the heat source side compressor 21 through the heat source side suction pipe 21c.

  On the other hand, in the usage-side refrigerant circuit 40a, the high-pressure usage-side refrigerant in the refrigeration cycle that circulates in the usage-side refrigerant circuit 40a is radiated by evaporation of the heat source-side refrigerant in the first usage-side heat exchanger 41a. The high-pressure use-side refrigerant that has radiated heat in the first use-side heat exchanger 41a is sent to the refrigerant-water heat exchange side flow rate adjustment valve 66a. The high-pressure use-side refrigerant sent to the refrigerant-water heat exchange side flow rate adjustment valve 66a is depressurized by the refrigerant-water heat exchange side flow rate adjustment valve 66a to become a low-pressure gas-liquid two-phase state, and the cascade-side liquid refrigerant. It is sent to the refrigerant-water heat exchanger 65a through the pipe 68a. The low-pressure use-side refrigerant sent to the refrigerant-water heat exchanger 65a evaporates in the refrigerant-water heat exchanger 65a by exchanging heat with the aqueous medium circulating in the aqueous medium circuit 80a by the circulation pump 43a. The low-pressure usage-side refrigerant evaporated in the refrigerant-water heat exchanger 65a is sent to the usage-side accumulator 67a through the first cascade-side gas refrigerant tube 72a and the first usage-side switching mechanism 64a. The low-pressure use-side refrigerant sent to the use-side accumulator 67a is sucked into the use-side compressor 62a through the cascade-side suction pipe 71a, compressed to a high pressure in the refrigeration cycle, and then discharged to the cascade-side discharge pipe 70a. . The high-pressure use-side refrigerant discharged to the cascade-side discharge pipe 70a is sent again to the first use-side heat exchanger 41a through the first use-side switching mechanism 64a and the second cascade-side gas refrigerant pipe 69a.

  In this way, the heat source side heat exchanger 24 is caused to function as a heat source side refrigerant radiator by setting the heat source side switching mechanism 23 to the heat source side heat radiation operation state, and the second usage side heat exchanger 101a is set to the heat source side. The refrigerant-water heat exchanger 65a is caused to function as a use-side refrigerant evaporator by causing the first use-side switching mechanism 64a to be in a use-side evaporation operation state, while functioning as a refrigerant evaporator, and the first use side A defrosting operation for causing the heat exchanger 41a to function as a heat radiator for the use side refrigerant (that is, as an evaporator for the heat source side refrigerant) is started.

  Then, it is determined whether or not a predetermined defrosting operation end condition is satisfied (that is, whether or not the defrosting of the heat source side heat exchanger 24 is completed) (step S23). Here, whether or not the heat source side heat exchanger temperature Thx has reached a predetermined defrosting completion temperature Thxs or a defrosting operation time tdf that is an elapsed time from the start of the defrosting operation is a predetermined defrosting operation setting time tdfs. It is determined whether or not the defrosting operation end condition is satisfied depending on whether or not it has been reached.

  And when it determines with satisfy | filling the defrost operation completion | finish conditions, the process which complete | finishes a defrost operation and returns to hot water supply operation mode is performed (step S24).

  Thus, in the heat pump system 300, when the heat source side heat exchanger 24 is defrosted, the heat source side heat exchanger 24 is placed in the heat source side heat dissipation operation state by setting the heat source side switching mechanism 23 to a heat source side refrigerant radiator. In addition, the refrigerant-water heat exchanger 65a functions as an evaporator for the use-side refrigerant by setting the first use-side switching mechanism 64a to the use-side evaporation operation state, and the first use-side heat exchange is performed. Since the heat exchanger 41a is caused to function as a radiator for the use side refrigerant, the heat source side refrigerant radiated and cooled by the heat source side heat exchanger 24 is radiated by the first use side heat exchanger 41a. It is possible to heat the use-side refrigerant that has been heated by the heat and cooled in the first use-side heat exchanger 41a by evaporating in the refrigerant-water heat exchanger 65a. Thus, it is possible to reliably perform defrosting of the heat source-side heat exchanger 24. In addition, since the second usage-side heat exchanger 101a also functions as a heat source-side refrigerant evaporator, the defrosting operation time tdf can be shortened, and the air cooled in the second usage unit 10a. It can suppress that the temperature of a medium becomes low.

(3) Modification 3
As in the heat pump system 300 (see FIG. 14) according to the second modification, the first heating-side heat exchanger 41a functions as a radiator for the heat-source-side refrigerant introduced from the discharge refrigerant communication tube 12, and In the configuration provided with the second usage side switching mechanism 53a capable of switching between the water medium cooling operation state in which the first usage side heat exchanger 41a functions as an evaporator of the heat source side refrigerant introduced from the liquid refrigerant communication tube 13. When the operation of the first usage unit 4a is stopped and the operation of the second usage unit 10a (cooling operation or heating operation) is performed (that is, when the discharge refrigerant communication pipe 12 is not used), the heat source side compressor The heat source side refrigerant discharged from 21 accumulates in the discharge refrigerant communication pipe 12, and the flow rate of the heat source side refrigerant drawn into the heat source side compressor 21 is insufficient (that is, the refrigerant circulation amount is insufficient). Have it.

  Therefore, in the heat pump system 300, as shown in FIG. 15, the discharge refrigerant communication pipe 12 and the gas refrigerant communication pipe 14 are used when the second usage side switching mechanism 53a is in either the aqueous medium heating operation state or the aqueous medium cooling operation state. Is provided with a first refrigerant recovery mechanism 57a. Here, the 1st refrigerant | coolant collection | recovery mechanism 57a is a refrigerant | coolant pipe | tube which has a capillary tube, and the one end connects the 1st utilization side discharge on-off valve 55a and the discharge refrigerant | coolant communication pipe | tube 12 among the 1st utilization side discharge refrigerant pipes 46a. The other end is connected to the connecting portion, and the other end is connected to the portion of the first usage-side gas refrigerant tube 54a that connects the first usage-side gas on / off valve 56a and the gas refrigerant communication tube 14, The discharge refrigerant communication pipe 12 and the gas refrigerant communication pipe 14 are communicated regardless of the open / close state of the use side discharge on / off valve 55a and the first use side gas on / off valve 56a.

  Thereby, in this heat pump system 300, since the heat-source-side refrigerant does not easily accumulate in the discharge refrigerant communication tube 12, it is possible to suppress the occurrence of insufficient refrigerant circulation in the heat-source-side refrigerant circuit 20.

  Further, as in the heat pump system 300 (see FIG. 14) in the second modification, the aqueous medium heating operation state in which the first usage-side heat exchanger 41a functions as a radiator for the heat-source-side refrigerant introduced from the discharge refrigerant communication tube 12 And a second second use side switching mechanism 53a capable of switching between a water medium cooling operation state in which the first use side heat exchanger 41a functions as an evaporator of the heat source side refrigerant introduced from the liquid refrigerant communication tube 13. In the provided configuration, when the operation of the first usage unit 4a is stopped and the operation of the second usage unit 10a (cooling operation or heating operation) is performed, the heat source side refrigerant accumulates in the first usage side heat exchanger 41a. Therefore, there is a possibility that the flow rate of the heat source side refrigerant sucked into the heat source side compressor 21 is insufficient (that is, the refrigerant circulation amount is insufficient).

  Therefore, in the heat pump system 300, as shown in FIG. 15, the first usage side heat exchanger 41a and the gas refrigerant are used in the second usage side switching mechanism 53a in both the aqueous medium heating operation state and the aqueous medium cooling operation state. A second refrigerant recovery mechanism 58a that communicates with the communication pipe 14 is provided. Here, the 2nd refrigerant | coolant collection | recovery mechanism 58a is a refrigerant | coolant pipe | tube which has a capillary tube, The one end is the gas side and 1st utilization side of the 1st utilization side heat exchanger 41a among the 1st utilization side gas refrigerant pipes 54a. The other end is connected to a portion connecting the first use side gas on / off valve 56a and the gas refrigerant communication tube 14 in the first use side gas refrigerant tube 54a. Even when the operation of the first usage unit 4a is stopped, the gas side and the gas refrigerant communication pipe of the first usage side heat exchanger 41a are bypassed by bypassing the first usage side gas on-off valve 56a. 14 is communicated.

  Thereby, in this heat pump system 300, since it becomes difficult for the heat source side refrigerant to accumulate in the 1st utilization side heat exchanger 41a, generation | occurrence | production of insufficient refrigerant | coolant circulation amount in the heat source side refrigerant circuit 20 can be suppressed.

  Furthermore, in the heat pump system 300 (see FIG. 14) in the modified example, the second usage side switching mechanism 53a is configured by the first usage side discharge on / off valve 55a and the first usage side gas on / off valve 56a. In any of the accompanying operation modes, the heat source side refrigerant is supplied to the first usage unit 4a only from the discharged refrigerant communication tube 12.

  However, in the hot water supply operation mode and the hot water supply / air heating operation mode among the operation modes involving the hot water supply operation, the heat source side refrigerant is at a high pressure in the refrigeration cycle not only in the discharge refrigerant communication tube 12 but also in the gas refrigerant communication tube 14. For this reason, in the hot water supply operation mode and the hot water supply / air heating operation mode, not only the discharge refrigerant communication tube 12 but also the gas refrigerant communication tube 14 may be able to send the high-pressure heat source side refrigerant to the first usage unit 4a. .

  Therefore, in the heat pump system 300, as shown in FIG. 15, the first usage-side gas check valve 59a and the first usage-side bypass refrigerant tube 60a are further provided in the first usage-side gas refrigerant tube 54a, A second usage side switching mechanism 53a is configured together with the usage side discharge on / off valve 55a and the first usage side gas on / off valve 56a. Here, the 1st utilization side gas check valve 59a is provided in the part which connects the 1st utilization side gas on-off valve 56a and the gas refrigerant communication pipe | tube 14 among the 1st utilization side gas refrigerant pipes 54a. The first usage-side gas check valve 59a allows the flow of the heat-source-side refrigerant from the first usage-side heat exchanger 41a toward the gas refrigerant communication tube 14, and from the gas refrigerant communication tube 14 to the first usage-side heat exchanger 41a. This is a check valve that prohibits the flow of the heat source side refrigerant toward the heat source side, whereby the flow of the heat source side refrigerant toward the first use side heat exchanger 41a from the gas refrigerant communication tube 14 through the first use side gas on-off valve 56a. Is now prohibited. The first usage-side bypass refrigerant pipe 60a is connected to the first usage-side gas refrigerant pipe 54a so as to bypass the first usage-side gas on-off valve 56a and the first usage-side gas check valve 59a. A part of the side gas refrigerant pipe 54a is constituted. The first usage-side bypass refrigerant pipe 60a allows the flow of the heat source-side refrigerant from the gas refrigerant communication pipe 14 toward the first usage-side heat exchanger 41a, and the first usage-side heat exchanger 41a passes the gas refrigerant communication pipe 14. A first usage-side bypass check valve 59a that prohibits the flow of the heat-source-side refrigerant toward the first usage-side heat exchange from the gas refrigerant communication tube 14 through the first usage-side bypass refrigerant tube 60a is provided. The flow of the heat source side refrigerant toward the container 41a is allowed.

  Thereby, in this heat pump system 300, in the hot water supply operation mode and the hot water supply heating operation mode, not only the discharge refrigerant communication tube 12 but also the gas refrigerant communication tube 14 can send the high-pressure heat source side refrigerant to the first usage unit 4a. As a result, the pressure loss of the heat-source-side refrigerant supplied from the heat source unit 2 to the first usage unit 4a is reduced, which can contribute to improvements in hot water supply capacity and operating efficiency.

(4) Modification 4
In the heat pump system 300 described above (see FIGS. 13 to 15), one first usage unit 4 a and one second usage unit 10 a are connected to the heat source unit 2 via the refrigerant communication tubes 12, 13, and 14. However, as shown in FIGS. 16 to 18 (here, illustration of the hot water heating unit, the hot water storage unit, the aqueous medium circuit 80a, 80b, etc. is omitted), a plurality of (here, two) first usage units. 4a and 4b are connected to each other in parallel via the refrigerant communication pipes 13 and 14, and / or a plurality (two in this case) of the second usage units 10a and 10b are connected to the refrigerant. The pipes 12, 13, and 14 may be connected to each other in parallel. Since the configuration of the first usage unit 4b is the same as that of the first usage unit 4a, the configuration of the first usage unit 4b is indicated by a suffix “a” indicating each part of the first usage unit 4a. Subscript “b” is attached instead of “,” and description of each part is omitted. In addition, since the configuration of the second usage unit 10b is the same as the configuration of the second usage unit 10a, the configuration of the second usage unit 10b is indicated by a suffix “a” indicating each part of the second usage unit 10a. Subscript “b” is attached instead of “,” and description of each part is omitted.

  Thereby, in these heat pump systems 300, it can respond to a plurality of places and uses which require heating of an aqueous medium, and can deal with a plurality of places and uses which require cooling of an air medium.

(5) Modification 5
In the heat pump system 300 described above (see FIGS. 13 to 18), the second usage-side flow rate adjustment valves 102a and 102b are provided in the second usage units 10a and 10b, but as shown in FIG. Then, the hot water heating unit, the hot water storage unit, the aqueous medium circuit 80a, etc. are not shown), the second usage side flow rate adjustment valves 102a, 102b are omitted from the second usage units 10a, 10b, An expansion valve unit 17 having 102a and 102b may be provided.

(Other embodiments)
As mentioned above, although embodiment of this invention and its modification were demonstrated based on drawing, specific structure is not restricted to these embodiment and its modification, It changes in the range which does not deviate from the summary of invention. Is possible.

<A>
In the heat pump systems 200 and 300 according to the second and third embodiments and the modifications thereof, the second usage units 10a and 10b are not usage units used for indoor air conditioning, and are different from air conditioning such as refrigeration and freezing. It may be used for a purpose.

<B>
In the heat pump system 300 according to the third embodiment and the modification thereof, for example, the gas refrigerant communication pipe 14 is connected to the low-pressure heat source side in the refrigeration cycle by communicating the second heat source side gas refrigerant pipe 23b and the heat source side suction pipe 21c. The second usage units 10a and 10b are used only for cooling so that the second usage-side heat exchangers 101a and 101b function only as an evaporator for the heat source-side refrigerant. It may be. Also in this case, operation in the hot water supply / cooling operation mode is possible, and energy saving can be achieved.

<C>
In the heat pump systems 1, 200, and 300 according to the first to third embodiments and the modifications thereof, the HFC-134a is used as the use-side refrigerant, but is not limited thereto, for example, HFO-1234yf ( 2, 3, 3, 3-tetrafluoro-1-propene) or the like, the pressure corresponding to the saturation gas temperature of 65 ° C. is at most 2.8 MPa or less, preferably 2.0 MPa or less. .

  By utilizing the present invention, a high-temperature aqueous medium can be obtained in a heat pump system that can heat an aqueous medium using a heat pump cycle.

DESCRIPTION OF SYMBOLS 1,200,300 Heat pump system 2 Heat source unit 4a, 4b 1st utilization unit 10a, 10b 2nd utilization unit 20 Heat source side refrigerant circuit 21 Heat source side compressor 23 Heat source side switching mechanism 24 Heat source side heat exchanger 40a, 40b Utilization side Refrigerant circuit 41a, 41b First use side heat exchanger 42a, 42b First use side flow rate adjustment valve 43a, 43b Circulation pump 62a, 62b Use side compressor 64a, 64b First use side switching mechanism 65a, 65b Refrigerant-hydrothermal Exchanger 66a, 66b Refrigerant-water heat exchange side flow rate adjustment valve 80a, 80b Aqueous circuit 101a, 101b Second usage side heat exchanger

JP 60-164157 A

Claims (15)

A capacity variable type heat source side compressor (21) for compressing the heat source side refrigerant, a first usage side heat exchanger (41a, 41b) capable of functioning as a heat source side refrigerant radiator, and a heat source side refrigerant A heat source side refrigerant circuit (20) having a heat source side heat exchanger (24) capable of functioning as a radiator;
Variable capacity use side compressors (62a, 62b) that compress the use side refrigerant, and refrigerant-water heat exchangers (65a, 65b) that function as a heat radiator for the use side refrigerant and can heat the aqueous medium. And a use side refrigerant circuit (40a, 40b) having the first use side heat exchanger (41a, 41b) capable of functioning as an evaporator of the use side refrigerant by radiating heat of the heat source side refrigerant. ,
The capacity control of the heat source side compressor is performed so that the heat source side discharge saturation temperature, which is a saturation temperature corresponding to the pressure of the heat source side refrigerant in the discharge of the heat source side compressor, becomes a predetermined target heat source side discharge saturation temperature,
Performing capacity control of the utilization side compressor so that the utilization side discharge saturation temperature, which is a saturation temperature corresponding to the pressure of the utilization side refrigerant in the discharge of the utilization side compressor, becomes a predetermined target utilization side discharge saturation temperature;
The heat source side refrigerant circuit includes a heat source side heat radiation operation state in which the heat source side heat exchanger functions as a heat source side refrigerant radiator and a heat source side evaporation operation state in which the heat source side heat exchanger functions as an evaporator of the heat source side refrigerant. And a heat source side switching mechanism (23) capable of switching between
The usage-side refrigerant circuit causes the refrigerant-water heat exchanger to function as a radiator for the usage-side refrigerant, and causes the first usage-side heat exchanger to function as an evaporator for the usage-side refrigerant; Use side switching capable of switching between a use side evaporation operation state in which the refrigerant-water heat exchanger functions as a use side refrigerant evaporator and the first use side heat exchanger functions as a use side refrigerant radiator. It further has a mechanism (64a, 64b),
When it is determined that defrosting of the heat source side heat exchanger is necessary, the heat source side heat exchanger is placed in the heat source side heat dissipation operation state by setting the heat source side switching mechanism to the heat source side refrigerant radiator. And functioning as a use side refrigerant evaporator by setting the use side switching mechanism to the use side evaporation operation state, and the first use side heat exchanger. Perform defrosting operation to function as a radiator for the usage-side refrigerant,
When performing the defrosting operation, after the heat source side switching mechanism is in the heat source side heat radiation operation state, the usage side switching mechanism is in the usage side evaporation operation state,
Heat pump system (1, 200, 300).   When performing the defrosting operation, the use side compressor (62a, 62b) is stopped and the use side switching mechanism (64a, 64b) is set to the use side evaporation operation state. The heat pump system according to (1, 200, 300). The use side refrigerant circuit (40a, 40b) is configured to change the flow rate of the use side refrigerant flowing through the refrigerant-water heat exchanger (65a, 65b). 66b)
When performing the defrosting operation, the use side compressors (62a, 62b) are stopped while the refrigerant-water heat exchange side flow rate control valve remains open.
The heat pump system (1, 200, 300) according to claim 2. The heat source side refrigerant circuit (20) includes first usage side flow rate control valves (42a, 42b) capable of varying the flow rate of the heat source side refrigerant flowing through the first usage side heat exchangers (41a, 41b). In addition,
The use side inlet / outlet pressure difference which is the pressure difference between the pressure of the use side refrigerant at the discharge of the use side compressor (62a, 62b) and the pressure of the use side refrigerant at the suction of the use side compressor is a predetermined use side low load. In the case of a control pressure difference or less, control is performed to reduce the opening of the first usage-side flow rate adjustment valve.
The heat pump system (1, 200, 300) according to any one of claims 1 to 3.   When the use side inlet / outlet pressure difference is larger than the use side low load control pressure difference, the heat source side refrigerant which is the degree of supercooling of the heat source side refrigerant at the outlet of the first use side heat exchanger (41a, 41b) The heat pump system (1, 200, 5) according to claim 4, wherein the degree of opening of the first usage-side flow rate adjustment valve (42a, 42b) is controlled so that the degree of supercooling becomes a predetermined target heat source side refrigerant subcooling degree. 300).   The heat pump system (1, 200, 300) according to claim 5, wherein when the use side inlet / outlet pressure difference is equal to or less than the use side low load control pressure difference, the target heat source side refrigerant subcooling degree is increased.   The said utilization side compressor is started after starting the said heat source side compressor, when starting from the state which the said heat source side compressor (21) and the said utilization side compressor (62a, 62b) stopped. The heat pump system (1, 200, 300) according to any one of 1 to 6.   The utilization side compressor (62a, 62b) is started after the pressure of the heat source side refrigerant in the discharge of the heat source side compressor (21) becomes equal to or higher than a predetermined heat source side activation discharge pressure. Heat pump system (1, 200, 300).   The heat source side inlet / outlet pressure difference, which is the pressure difference between the pressure of the heat source side refrigerant in the discharge of the heat source side compressor (21) and the pressure of the heat source side refrigerant in the suction of the heat source side compressor, is greater than or equal to a predetermined heat source side starting pressure difference. The heat pump system (1, 200, 300) according to claim 7, wherein the use side compressor (62a, 62b) is started after becoming. An aqueous medium circuit (having variable capacity type circulation pumps (43a, 43b)) in which an aqueous medium that performs heat exchange with the use-side refrigerant in the refrigerant-water heat exchanger (65a, 65b) circulates ( 80a, 80b),
The use side compressor (62a, 62b) is started in a state where the circulating pump is stopped or operated at a small flow rate.
The heat pump system (1, 200, 300) according to any one of claims 1 to 9.   The flow rate of the aqueous medium circulating through the aqueous medium circuit (80a, 80b) becomes large after the pressure of the utilization side refrigerant in the discharge of the utilization side compressor (62a, 62b) becomes equal to or higher than a predetermined utilization side start discharge pressure. The heat pump system (1, 200, 300) according to claim 10, wherein the capacity control of the circulation pump (43a, 43b) is performed so as to be.   The use side inlet / outlet pressure difference, which is the pressure difference between the pressure of the use side refrigerant at the discharge of the use side compressor (62a, 62b) and the pressure of the use side refrigerant at the suction of the use side compressor, is a predetermined use side starting pressure. 11. The heat pump system according to claim 10, wherein the capacity control of the circulation pumps (43 a, 43 b) is performed so that a flow rate of the aqueous medium circulating in the aqueous medium circuit (80 a, 80 b) is increased after the difference is exceeded. (1, 200, 300). A capacity variable type heat source side compressor (21) for compressing the heat source side refrigerant, a first usage side heat exchanger (41a, 41b) capable of functioning as a heat source side refrigerant radiator, and a heat source side refrigerant A heat source side refrigerant circuit (20) having a heat source side heat exchanger (24) capable of functioning as a radiator;
Variable capacity use side compressors (62a, 62b) that compress the use side refrigerant, and refrigerant-water heat exchangers (65a, 65b) that function as a heat radiator for the use side refrigerant and can heat the aqueous medium. And a use side refrigerant circuit (40a, 40b) having the first use side heat exchanger (41a, 41b) capable of functioning as an evaporator of the use side refrigerant by radiating heat of the heat source side refrigerant. ,
The capacity control of the heat source side compressor is performed so that the heat source side discharge saturation temperature, which is a saturation temperature corresponding to the pressure of the heat source side refrigerant in the discharge of the heat source side compressor, becomes a predetermined target heat source side discharge saturation temperature,
Performing capacity control of the utilization side compressor so that the utilization side discharge saturation temperature, which is a saturation temperature corresponding to the pressure of the utilization side refrigerant in the discharge of the utilization side compressor, becomes a predetermined target utilization side discharge saturation temperature;
The heat source side refrigerant circuit further includes a second usage side heat exchanger (101a, 101b) capable of heating the air medium by functioning as a heat source side refrigerant radiator.
When performing the operation for causing the second usage side heat exchanger to function as a heat radiator for the heat source side refrigerant, compared with the case for performing the operation for causing the second usage side heat exchanger to function as a radiator for the heat source side refrigerant. Increasing the target heat source side discharge saturation temperature,
Heat pump system (200, 300).   The heat source side refrigerant circuit (20) further includes a second usage side heat exchanger (101a, 101b) capable of cooling the air medium by functioning as an evaporator of the heat source side refrigerant, It is possible to perform an operation for causing the first usage-side heat exchanger (41a, 41b) to function as a heat-source-side refrigerant radiator and an operation for causing the second usage-side heat exchanger to function as an evaporator for the heat-source-side refrigerant. The heat pump system (300) according to any one of claims 1 to 12, wherein There are a plurality of the first use side heat exchangers (41a, 41b),
A plurality of the use side refrigerant circuits (40a, 40b) are provided so as to correspond to the respective first use side heat exchangers,
The heat pump system (1, 200, 300) according to any one of claims 1 to 14.

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