JP2007183045A - Heat pump type air-conditioning equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve operation efficiency when operating a plurality of indoor loads in heat pump type air-conditioning equipment cooling and heating the indoor loads via a secondary coolant. <P>SOLUTION: The heat pump type air-conditioning equipment has a compressor 1, a four-way valve 2, an outdoor heat exchanger 6, a heat pump circuit 7 forming a closed circuit by connecting expansion valves 5a, 5b and coolant-to-coolant heat exchangers 4a, 4b by coolant piping, and sealing a primary coolant, and load circuits 11a, 11b circulating the secondary coolant to exchange heat with the primary coolant between the coolant-to-coolant heat exchanger 4 and the indoor load 9. It is characterized by that in the heat pump circuit 7, a plurality of the coolant-to-coolant heat exchangers 4a, 4b are arranged in parallel with each other, and a flow adjuster 3 is provided for controlling a flow rate of the primary coolant flowing through each coolant-to-coolant heat exchanger 4. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a heat pump type air conditioner.

  Conventionally, heat pumps have been widely used as heat sources for air conditioners and electric refrigerators. The heat pump air conditioner is provided with a heat pump circuit in which a compressor, a heat dissipation heat exchanger, an expansion valve, and an endothermic heat exchanger are connected in an annular shape. The outside air is heated by exchanging heat between the fluorocarbon refrigerant and the outside air.

By the way, it is known that a chlorofluorocarbon refrigerant destroys an ozone layer and becomes a greenhouse gas. For this reason, attempts have been made to use carbon dioxide (CO ₂ ) or the like as a refrigerant for a heat pump air conditioner, which has an ozone layer depletion coefficient of zero and a global warming coefficient that is much smaller than that of a fluorocarbon refrigerant. . According to this carbon dioxide refrigerant, for example, the heating efficiency of air or water can be improved.

  However, a refrigerant that operates at a supercritical pressure, such as carbon dioxide, is usually operated in the super-high pressure zone on the high-pressure side of the refrigerant. For example, an indoor unit such as a heat pump air conditioner that uses a fluorocarbon refrigerant is used. In the configuration in which heat exchangers are arranged in the outdoor unit and connected to each other by piping, there is a possibility that refrigerant leakage or piping rupture may occur unless any high-pressure measures are taken. Therefore, for example, carbon dioxide as the primary refrigerant is circulated in the heat pump circuit installed outside the room, while water or antifreeze liquid as the secondary refrigerant is heat-exchanged with the primary refrigerant and then sent into the room via a pipe. Therefore, a method of performing indoor air conditioning has been studied (for example, see Patent Document 1).

  There is also known a heat pump air conditioner that includes one indoor load such as an air conditioner or floor heating and operates the same. Such an air conditioner is usually provided with a load circuit that circulates the secondary refrigerant between the inter-refrigerant heat exchanger provided in the heat pump circuit and the indoor load, and the secondary refrigerant of the load circuit is used as the primary refrigerant. The indoor load is operated by exchanging heat with.

JP 2004-177067 A

  By the way, in the case of a heat pump type air conditioning apparatus having a plurality of load circuits, for example, a plurality of inter-refrigerant heat exchangers that exchange heat with a secondary refrigerant are connected to the heat pump circuit, and the heat exchange between these refrigerants A separate load circuit is connected to the device. In general, the required amount of heating heat differs between the air conditioning heating load and the floor heating load.

  Therefore, for example, the high-temperature refrigerant discharged from the compressor during the heating operation gradually decreases in heating capacity as it passes through the inter-refrigerant heat exchanger. For this reason, when a plurality of indoor loads are operated at the same time, it becomes difficult to supply the amount of heat required from each of the indoor loads, and there is a problem that heating efficiency is reduced.

  This invention makes it a subject to improve the operation efficiency at the time of drive | operating several indoor load in the heat pump type air conditioning apparatus which air-conditions and cools indoor load via a secondary refrigerant | coolant.

  In order to solve the above problems, the present invention forms a closed circuit by connecting a compressor, a four-way valve, an outdoor heat exchanger, an expansion valve, and an inter-refrigerant heat exchanger with a refrigerant pipe, and a primary refrigerant is enclosed. In a heat pump air conditioner having a heat pump circuit and a load circuit that circulates a secondary refrigerant that exchanges heat with the primary refrigerant between the inter-refrigerant heat exchanger and the indoor load, the heat pump circuit includes a plurality of inter-refrigerant heat exchangers. Are provided in parallel and provided with a flow rate adjusting means for adjusting the flow rate of the primary refrigerant flowing through each of the inter-refrigerant heat exchangers.

  According to such a configuration, for example, when operating a plurality of indoor loads at the same time in the heating operation, first, the primary refrigerant discharged from the compressor is branched into the respective heat exchangers after being branched. Led. The heating capacity of the heat pump circuit is appropriately distributed by adjusting the flow rate of the primary refrigerant flowing through each of the refrigerant heat exchangers according to the required amount of heat of the load circuit connected to each refrigerant heat exchanger. Therefore, driving efficiency can be improved.

  Specifically, it is assumed that the flow rate adjusting means includes an expansion valve arranged in correspondence with each inter-refrigerant heat exchanger. In other words, the flow rate of the primary refrigerant can be adjusted by adjusting the throttle of the expansion valve according to the required amount of heat of the load corresponding to each refrigerant heat exchanger, so the heating capacity of the heat pump circuit is reduced. It can be distributed as appropriate to improve the operation efficiency.

  Furthermore, the flow rate adjusting means includes a flow rate adjusting valve disposed on the opposite side of the expansion valve across the inter-refrigerant heat exchanger. According to this, for example, in heating operation, the primary refrigerant discharged from the compressor at a predetermined temperature is adjusted to a predetermined flow rate via each flow rate adjustment valve and then introduced into the inter-refrigerant heat exchanger. In addition, a desired heating capacity is distributed to each inter-refrigerant heat exchanger, and the operation efficiency can be improved.

  Further, the heat pump circuit can increase the enthalpy of the heat absorption process and the heat dissipation process by providing an auxiliary heat exchanger that exchanges heat between the high-pressure side refrigerant and the low-pressure side refrigerant of the primary refrigerant, thereby further improving the operation efficiency. be able to.

  In such a configuration, for example, a carbon dioxide refrigerant is preferably used as the primary refrigerant, and water or an antifreeze liquid is preferably used as the secondary refrigerant.

  According to the present invention, it is possible to improve the operation efficiency when operating a plurality of indoor loads.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, a first embodiment of the invention will be described with reference to the drawings. FIG. 1 is an overall configuration diagram of a heat pump type air conditioner to which the present invention is applied.

  The heat pump type air conditioning apparatus of the present embodiment includes a heat pump circuit 7, an air conditioning circuit 11a, and a floor heating circuit 11b. The heat pump circuit 7 includes a compressor 1, a cooling / heating cycle switching four-way valve 2, cycle flow path switching valves 3a and 3b, refrigerant heat exchangers 4a and 4b, expansion valves 5a and 5b, and an outdoor heat exchanger 6. A closed circuit sequentially connected by refrigerant piping, a flow path switching valve 3a, an inter-refrigerant heat exchanger 4a, a flow path for indoor air conditioning connecting the expansion valve 5a, a cycle flow path switching valve 3b, and an inter-refrigerant heat exchanger The floor heating flow path connecting 4b and the expansion valve 5b is arranged in parallel. Here, carbon dioxide is enclosed in the heat pump circuit 7 as a primary refrigerant.

  The cycle channel switching valves 3a and 3b can switch between a channel for indoor air conditioning and a channel for floor heating by opening and closing the valve. Further, by adjusting the flow rate of the primary refrigerant by adjusting the valve opening, the air conditioning and the floor heating can be distributed and operated simultaneously. The rotation speed of the compressor 1 can be adjusted freely from low speed rotation to high speed rotation. The outdoor heat exchanger 6 exchanges heat between air sent from a fan (not shown) and the primary refrigerant.

  The inter-refrigerant heat exchanger 4a includes a primary heat transfer tube 4c through which the primary refrigerant flows and a secondary heat transfer tube 4d through which the secondary refrigerant flows. The inter-refrigerant heat exchanger 4b includes the primary heat transfer tube 4c. A primary side heat transfer tube 4e through which the refrigerant flows and a secondary side heat transfer tube 4f through which the secondary refrigerant flows are configured.

  The air conditioning circuit 11a is a closed circuit in which the circulation pump 8a, the inter-refrigerant heat exchanger 4a, the indoor air conditioning heat exchanger 9a, the buffer tank 10a, and the circulation pump 8a are sequentially connected by refrigerant piping, and water or antifreeze liquid as a secondary refrigerant. Is used. The floor heating circuit 11b is a closed circuit in which the circulation pump 8b, the inter-refrigerant heat exchanger 4b, the floor heating panel 9b, the buffer tank 10b, and the circulation pump 8b are sequentially connected by refrigerant piping, and water or antifreeze liquid is enclosed as a secondary refrigerant. Has been. The buffer tanks 10a and 10b are normally used as water supply ports during installation.

  The heat pump circuit 7 and the inter-refrigerant heat exchangers 4a and 4b are provided in the outdoor unit, and the indoor unit includes an indoor air-conditioning heat exchanger 9a connected to the inter-refrigerant heat exchangers 4a and 4b through refrigerant pipes, and floor heating. A panel 9b is provided.

  The control device 16 controls operations of the heat pump circuit 7, the air conditioning circuit 11a, the floor heating circuit 11b, and the like based on, for example, a temperature signal from a temperature sensor (not shown), an operation command signal from a remote controller input by the user, and the like. Specifically, in the heat pump circuit 7, along with the operation of the compressor 1, the valve opening degrees of the cycle flow path switching valves 3a and 3b and the expansion valves 5a and 5b are operated to control the flow rate and flow path of the primary refrigerant. ing. On the other hand, in the air conditioning circuit 11a and the floor heating circuit 11b, the operations of the circulation pumps 8a and 8b are controlled to start and stop the respective indoor loads.

  Next, the operation of this embodiment will be described.

  First, the basic operation of the heat pump circuit 7 during heating operation will be described. The high-temperature and high-pressure primary refrigerant compressed by the compressor 1 is branched via the four-way valve 2 and then the inter-refrigerant heat exchanger. 4a and 4b are respectively introduced into the primary side heat transfer tubes 4c and 4e to heat and dissipate the water flowing through the secondary side heat transfer tubes 4d and 4f. After passing through the primary heat transfer tubes 4c, 4e, the primary refrigerant that has been expanded by being led to the expansion valves 5a, 5b evaporates due to heat absorption in the outdoor heat exchanger 6, and then passes through the four-way valve 2 to compress the compressor 1. Sucked into.

  Here, when only floor heating is performed, the heat pump circuit 7 is operated, and the circulation pump 8b is activated to circulate the secondary refrigerant in the floor heating circuit 11b. Further, in the air conditioning circuit 11a, the circulation pump 8a is not started but is brought into a stopped state. At this time, the heat pump circuit 7 fully closes the cycle flow path switching valve 3a and the expansion valve 5a, and fully opens the cycle flow path switching valve 3b and the expansion valve 5b, so that the primary refrigerant delivered from the compressor 1 is a refrigerant. It is introduced only into the intermediate heat exchanger 4b.

  On the other hand, when operating only indoor air conditioning, while operating the heat pump circuit 7, the circulation pump 8a is started and the secondary refrigerant in the air conditioning circuit 11a is circulated. Further, in the floor heating circuit 11b, the circulation pump 8b is not started but is brought into a stopped state. At this time, the heat pump circuit 7 fully closes the cycle flow path switching valve 3b and the expansion valve 5b and fully opens the cycle flow path switching valve 3a and the expansion valve 5a, so that the primary refrigerant sent out from the compressor 1 is a refrigerant. It is introduced only into the intermediate heat exchanger 4a.

  Such an operation makes it possible to create a cycle in which indoor air conditioning and floor heating are independently operated. On the other hand, when operating indoor air conditioning and floor heating simultaneously, the heat pump circuit 7, the air conditioning circuit 11a, and the floor heating circuit 11b are operated, and the primary refrigerant and the secondary refrigerant are all in the operating state. At this time, the heat pump circuit 7 adjusts all the opening degrees of the cycle flow path switching valves 3a and 3b and the expansion valves 5a and 5b, and adjusts the circulation amount of the primary refrigerant in the flow path for indoor air conditioning and floor heating. . Alternatively, it may be performed by adjusting the amount of pressure reduction by the expansion valves 5a and 5b, or by adjusting the opening of the switching valves 3a and 3b.

  In the present embodiment, in the heating operation, in order to switch the flow paths for indoor air conditioning and floor heating, cycle flow path switching valves 3a and 3b are respectively installed on the inlet side of the inter-refrigerant heat exchangers 4a and 4b. However, the flow rate of the primary refrigerant passing through the inter-refrigerant heat exchangers 4a and 4b, that is, the pressure reduction amount is adjusted by adjusting the valve opening degree of the cycle flow path switching valves 3a and 3b. That is, the heat pump circuit 7 is adjusted by adjusting the valve opening degree of the cycle flow path switching valves 3a and 3b and adjusting the flow rate of the primary refrigerant in accordance with the required load (required heat amount) of the indoor air conditioning and floor heating. Can be appropriately distributed to the inter-refrigerant heat exchangers 4a and 4b, and the heating efficiency can be improved.

  Here, for example, the load change of each indoor load is detected, and the load signal is input to the control device 16 for processing, and the cycle flow path switching valves 3a and 3b are opened based on the magnitude of the load. The degree may be controlled. According to this, since a heating capability can be appropriately distributed at an optimal ratio according to a load change of each indoor load, a high heating capability can be maintained.

  Further, for example, a temperature sensor for detecting the temperature of the primary refrigerant is provided on the inlet side of the inter-refrigerant heat exchangers 4a and 4b, and the control device 16 opens the cycle flow path switching valves 3a and 3b based on the detected temperature. The degree may be controlled. According to this, the heating capability of the heat pump circuit 7 can be distributed with high accuracy.

  Further, during the cooling operation, the four-way valve 2 is switched to the cooling cycle to operate the heat pump circuit 7 and the circulation pump 8a is activated to circulate the secondary refrigerant of the air conditioning circuit 11a, while the floor heating circuit 11b is connected to the circulation pump 8b. No operation is performed and the vehicle is stopped. Then, the cycle flow path switching valve 3b and the expansion valve 5b are fully closed, and the cycle flow path switching valve 3a and the expansion valve 5a are fully opened, so that the primary refrigerant that has passed through the outdoor heat exchanger 6 becomes an inter-refrigerant heat exchanger. It is introduced only in 4a. Thereby, the cooling operation by the air conditioning circuit 11a becomes possible.

  In the present embodiment, in the case of the cooling operation, the single operation by the indoor air conditioning is performed. However, for example, in the case of a configuration in which a plurality of indoor air conditionings are operated simultaneously, the expansion valve 5 and the cycle flow path switching valve 3 are used. By adjusting the flow rate of the primary refrigerant, the cooling capacity of the heat pump circuit 7 can be appropriately distributed to each inter-refrigerant heat exchanger 4, so that the operating efficiency can be improved as in the heating operation.

  Next, a second embodiment of the present invention will be described with reference to the drawings. FIG. 2 is an overall configuration diagram of a heat pump air conditioner to which the present invention is applied. In this embodiment, since the same circuit configuration as that of the first embodiment is used, the same components are denoted by the same reference numerals and description thereof is omitted.

  The heat pump type air conditioner of the present embodiment is the first embodiment in that the heat pump circuit 15 is provided with the auxiliary heat exchanger 14 to exchange heat between the high pressure side and the low pressure side of the carbon dioxide refrigerant that is the primary refrigerant. It is different from the heat pump type air conditioner.

  The heat pump type air conditioning apparatus of the present embodiment includes a heat pump circuit 15, an air conditioning circuit 11a, and a floor heating circuit 11b. The heat pump circuit 15 is configured so that, during the heating operation, the high-temperature and high-pressure primary refrigerant compressed by the compressor 1 is branched through the four-way valve 2 and then the primary heat transfer tubes between the refrigerant heat exchangers 4a and 4b. Introduced into 4c and 4e, the water flowing through the secondary heat transfer tubes 4d and 4f is heated and radiated. After passing through the primary side heat transfer tubes 4c and 4e, the primary refrigerant joined through the cooling operation expansion valve 12 and the floor heating flow path switching valve 13 is supplied to the outdoor heat exchanger 6 by the auxiliary heat exchanger 14. Heat exchange with the primary refrigerant exiting Subsequently, the primary refrigerant that has been led to the expansion valve 17 for heating operation and expanded is evaporated by heat absorption in the outdoor heat exchanger 6 and then sucked into the compressor 1 via the four-way valve 2.

  Here, when only floor heating is operated, the heat pump circuit 15 is operated and the circulation pump 8b is activated to circulate the secondary refrigerant in the floor heating circuit 11b. Further, in the air conditioning circuit 11a, the circulation pump 8a is not started but is brought into a stopped state. At this time, the heat pump circuit 15 fully closes the cycle flow path switching valve 3a and the cooling operation expansion valve 12, and fully opens the cycle flow path switching valve 3b and the floor heating flow path switching valve 13, whereby the compressor 1 is introduced only into the inter-refrigerant heat exchanger 4b.

  On the other hand, when operating only indoor air conditioning, while operating the heat pump circuit 15, the circulation pump 8a is started and the secondary refrigerant in the air conditioning circuit 11a is circulated. Further, in the floor heating circuit 11b, the circulation pump 8b is not started but is brought into a stopped state. At this time, the heat pump circuit 15 fully closes the cycle flow path switching valve 3b and the floor heating flow path switching valve 13 and fully opens the cycle flow path switching valve 3a and the cooling operation expansion valve 12, thereby compressing the compressor. 1 is introduced only into the inter-refrigerant heat exchanger 4a.

  Such an operation makes it possible to create a cycle in which indoor air conditioning and floor heating are independently operated. On the other hand, when operating indoor air conditioning and floor heating at the same time, the heat pump circuit 15, the air conditioning circuit 11a, and the floor heating circuit 11b are operated, and the primary refrigerant and all the secondary refrigerants are set in the operating state. At this time, the heat pump circuit 15 fully opens the cycle flow path switching valves 3a and 3b, the cooling operation expansion valve 12, and the floor heating flow path switching valve 13, and the primary refrigerant in the flow path for indoor air conditioning and floor heating. The circulation amount is adjusted, for example, by adjusting the flow rate (pressure reduction amount) using the heating operation expansion valve 17 and the cycle flow path switching valves 3a and 3b.

  In particular, the heat pump circuit 15 is adjusted by adjusting the valve opening degree of the cycle flow path switching valves 3a and 3b and adjusting the flow rate of the primary refrigerant according to the required load (required heat amount) of the indoor air conditioning and floor heating. Can be appropriately distributed to the inter-refrigerant heat exchangers 4a and 4b to improve the heating efficiency.

  Further, during the cooling operation, the four-way valve 2 is switched to the cooling cycle to operate the heat pump circuit 15, the air conditioning circuit 11a circulates the secondary refrigerant, and the floor heating circuit 11b stops the operation. Then, the cycle flow switching valve 3b and the floor heating flow switching valve 13 are fully closed, and the cycle flow switching valve 3a and the cooling operation expansion valve 12 are fully opened, thereby passing the outdoor heat exchanger 6. A primary refrigerant | coolant is introduce | transduced only into the heat exchanger 4a between refrigerant | coolants, and the cooling operation by the air-conditioning circuit 11a is attained. Here, the adjustment of the circulation amount of the primary refrigerant is performed by the cooling operation expansion valve 12.

  Furthermore, in the present embodiment, the primary refrigerant at the outlet side of each of the outdoor heat exchanger 6 and the inter-refrigerant heat exchangers 4a and 4b is heat-exchanged by the auxiliary heat exchanger 14 during cooling and heating operations. . Thereby, in addition to the effect of 1st Embodiment, the enthalpy of a thermal radiation process and an endothermic process can be increased, and operating efficiency can be improved further.

  As described above, according to the configuration of the above embodiment, in the heat pump air conditioner that cools and heats the indoor load via the secondary refrigerant, for example, an indoor air conditioner such as an indoor unit for a room air conditioner or a floor heater Thus, the load operation by a plurality of indoor heat exchangers can be operated simultaneously or selectively. Moreover, according to the said embodiment, even if it uses as a primary refrigerant | coolant the carbon dioxide refrigerant | coolant etc. which operate | move by a supercritical state (pressure) on the high voltage | pressure side, it can perform an air conditioning operation without trouble with high heating and cooling capability.

  Moreover, in the heat pump type air conditioning apparatus of the said embodiment, the several heat exchanger 4 between refrigerant | coolants is arrange | positioned in parallel, and the cycle flow-path switching valve 3 is provided in the entrance side of the primary refrigerant | coolant of each heat exchanger 4 between refrigerant | coolants. Thus, the flow rate of the primary refrigerant flowing into the inter-refrigerant heat exchanger 4 can be adjusted. For example, even when a plurality of indoor loads having different heating capacities are simultaneously operated during the heating operation, according to each required load The heating capacity of the heat pump circuit can be appropriately distributed, and the operation can be performed efficiently.

  In the above embodiment, an example in which carbon dioxide is used as the primary refrigerant has been described. However, the present invention is not limited to this. For example, ethane, flammable refrigerant propane, isobutane, or the like may be used.

  Moreover, although the said embodiment demonstrated the example which uses air conditioners, such as an air conditioner, and a floor heating apparatus as an indoor load, it is not limited to this, Other cooling / heating loads (for example, mist sauna, wall surface cooling, It can also be applied to ceiling cooling), and can also be applied to a configuration in which two or more indoor loads are connected.

1 is an overall configuration diagram of a heat pump air conditioner in a first embodiment of the present invention. It is a whole block diagram of the heat pump type air conditioning apparatus in the 2nd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Compressor 2 Four-way valve 3a, 3b Cycle flow path switching valve 4a, 4b Inter-refrigerant heat exchanger 5a, 5b Expansion valve 6 Outdoor heat exchanger 7 Heat pump circuit 8a, 8b Circulation pump 9a Heat exchanger 9a for indoor air conditioning 9b Floor heating Panel 11a Air conditioning circuit 11b Floor heating circuit 14 Auxiliary heat exchanger

Claims (6)

A compressor, a four-way valve, an outdoor heat exchanger, an expansion valve, and an inter-refrigerant heat exchanger are connected by a refrigerant pipe to form a closed circuit, and a heat pump circuit in which the primary refrigerant is enclosed and heat exchange with the primary refrigerant In a heat pump air conditioner having a load circuit for circulating a secondary refrigerant between the inter-refrigerant heat exchanger and an indoor load,
The heat pump circuit is characterized in that a plurality of the inter-refrigerant heat exchangers are provided in parallel, and includes a flow rate adjusting means for adjusting the flow rate of the primary refrigerant flowing through each of the inter-refrigerant heat exchangers. Air conditioning unit. The heat pump air-conditioning / heating apparatus according to claim 1, wherein the flow rate adjusting means includes the expansion valve disposed in correspondence with each of the refrigerant heat exchangers. The heat pump air conditioner according to claim 2, wherein the flow rate adjusting means includes a flow rate adjusting valve disposed on the opposite side of the expansion valve across the refrigerant heat exchangers. The heat pump type air conditioning apparatus according to any one of claims 1 to 3, wherein the heat pump circuit includes an auxiliary heat exchanger that exchanges heat between the high-pressure side refrigerant and the low-pressure side refrigerant of the primary refrigerant. The heat pump air conditioner according to any one of claims 1 to 4, wherein the primary refrigerant is a carbon dioxide refrigerant, and the secondary refrigerant is water or antifreeze. 6. The heat pump air conditioner according to claim 5, wherein the carbon dioxide refrigerant is in a supercritical state on the high pressure side.

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