JP7041024B2 - Combined heat source heat pump device - Google Patents

Description

The present invention relates to a combined heat source heat pump device that switches between a main power source and an auxiliary power source.

Conventionally, in this type of combined heat source heat pump device, a first heat pump circuit that exchanges heat with a heat medium and a second heat pump circuit having an air heat exchanger that exchanges heat with outside air are provided, and the outside air temperature and a predetermined switching temperature are set. By comparison, the compressor of one of the heat pump circuits is used as the main power source, and the compressor of the other heat pump circuit is used as the auxiliary power source for drive control. Some of them drive both of the compressors of the main power source to operate, or drive only the compressor of the main power source with the drive of the compressor of the auxiliary power source stopped. (See, for example, Patent Document 1.)

Japanese Unexamined Patent Publication No. 2016-40500

By the way, in this conventional case, when the operation is performed by driving only the compressor of the main power source while the drive of the compressor of the auxiliary power source is stopped, the outside air temperature changes to a predetermined switching temperature during the operation. By changing to exceed, switching between the main power source and the auxiliary power source may occur, and the compressor that was driven as the main power source until then is set to the auxiliary power source and stops, and the auxiliary power is stopped until then. The compressor, which has stopped driving as a source, is set as the main power source and starts driving.

As described above, when the operation is performed by driving only the compressor of the main power source, the situation where the switching between the main power source and the auxiliary power source occurs is that only the compressor of the main power source is driven. When switching between the main power source and the auxiliary power source occurs due to the rise in the outside air temperature during the heating operation, and when the heating operation is performed by driving only the compressor of the main power source. In addition, the outside air temperature rises when the main power source / auxiliary power source is switched due to the decrease in the outside air temperature, and when only the compressor of the main power source is driven for cooling operation. When switching between the main power source and the auxiliary power source occurs, and when the cooling operation is performed by driving only the compressor of the main power source, the outside air temperature drops and the main power source / auxiliary power source is used. There are four patterns with the case where switching occurs, and the drive start timing of the main power source and the drive stop timing of the auxiliary power source after switching between the main power source and the auxiliary power source are controlled in the same manner in all the four patterns. In some cases, the temperature of the hot water or cold water generated when switching between the main power source and the auxiliary power source fluctuates greatly, and there is a risk that stable operation cannot be performed and comfort is impaired.

In order to solve the above problems, the present invention has the first aspect that heat exchange is possible with a first compressor, a first load side heat exchanger, a first expansion valve, and a predetermined heat source other than the outside air. It is equipped with a first heat pump circuit equipped with one heat source side heat exchanger, a second compressor, a second load side heat exchanger, a second expansion valve, and a second heat source side heat exchanger capable of exchanging heat with outside air. A second heat pump circuit, a load side circulation circuit provided with the first load side heat exchanger, the second load side heat exchanger, and a load terminal for circulating hot or cold water, and an outside air temperature detection for detecting the outside air temperature. The control device includes means and a control device for controlling the operation, and the control device switches the outside air temperature detected by the outside air temperature detecting means to a predetermined value during operation when hot water or cold water is supplied to the load terminal. In a combined heat source heat pump device that switches which of the first compressor and the second compressor is the main power source and which is the auxiliary power source depending on whether the temperature is higher or lower, only the main power source is used. During the driving operation, the control device is based on the fact that the outside air temperature detected by the outside air temperature detecting means changes in the direction in which the load increases and reaches the predetermined switching temperature. When switching between and the auxiliary power source, the driving of the main power source after the switching is started, and the driving of the auxiliary power source after the switching is stopped. After controlling the drive of both the main power source and the auxiliary power source after switching so as to overlap, the drive of the auxiliary power source after switching is controlled to be stopped, and only the main power source is driven. During the operation, the control device and the main power source are based on the fact that the outside air temperature detected by the outside air temperature detecting means changes in the direction in which the load decreases and reaches the predetermined switching temperature. When the auxiliary power source is switched, the driving of the main power source after the switching is started and the driving of the auxiliary power source after the switching is stopped, and the second predetermined time is shorter than the first predetermined time. During the time, the drive of both the main power source after switching and the auxiliary power source after switching is controlled to overlap, and then the drive of the auxiliary power source after switching is controlled to be stopped. I said.

Further, according to claim 2, when the outside air temperature detected by the outside air temperature detecting means is equal to or higher than the predetermined switching temperature during the heating operation in which hot water is supplied to the load terminal, the control device is the first. When the 2 compressors are set as the main power source and the first compressor is set as the auxiliary power source, and the outside air temperature detected by the outside air temperature detecting means is less than the predetermined switching temperature, the first compression is performed. During the heating operation in which the machine is set as the main power source and the second compressor is set as the auxiliary power source and only the second compressor as the main power source is driven, the control device is used for the outside air. When the main power source and the auxiliary power source are switched based on the fact that the outside air temperature detected by the temperature detecting means has decreased and reached the predetermined switching temperature, the main power source becomes the main power source after the switching. In starting the drive of the first compressor and stopping the drive of the second compressor, which is the auxiliary power source after switching, the first, which becomes the main power source after switching for the first predetermined time. After controlling so that the drives of both the compressor and the second compressor, which is the auxiliary power source, overlap after switching, the drive of the second compressor, which is the auxiliary power source, is stopped after the switching. During the heating operation, which is controlled and driven only by the first compressor as the main power source, the control device raises the outside air temperature detected by the outside air temperature detecting means to raise the predetermined switching temperature. When the main power source and the auxiliary power source are switched based on the above, the driving of the second compressor, which is the main power source, is started after the switching, and the auxiliary power source is started after the switching. In stopping the drive of the first compressor, the second compressor that becomes the main power source after switching and the auxiliary power source after switching for the second predetermined time shorter than the first predetermined time. After controlling so that the drives of both of the first compressors overlap each other, the drive of the first compressor, which is the auxiliary power source, is controlled to be stopped after switching.

Further, according to claim 3, when the outside air temperature detected by the outside air temperature detecting means is equal to or higher than the predetermined switching temperature during the cooling operation in which the load terminal is supplied with cold water, the control device is the first. When one compressor is set as the main power source and the second compressor is set as the auxiliary power source, and the outside air temperature detected by the outside air temperature detecting means is less than the predetermined switching temperature, the second compression is performed. During the cooling operation in which the machine is set as the main power source and the first compressor is set as the auxiliary power source and only the second compressor as the main power source is driven, the control device is used for the outside air. When the main power source and the auxiliary power source are switched based on the fact that the outside air temperature detected by the temperature detecting means rises and reaches the predetermined switching temperature, the main power source becomes the main power source after the switching. In starting the drive of the first compressor and stopping the drive of the second compressor, which is the auxiliary power source after switching, the first, which becomes the main power source after switching for the first predetermined time. After controlling so that the drives of both the compressor and the second compressor, which is the auxiliary power source, overlap after switching, the drive of the second compressor, which is the auxiliary power source, is stopped after the switching. During the cooling operation, which is controlled and driven only by the first compressor as the main power source, the control device reduces the outside air temperature detected by the outside air temperature detecting means to the predetermined switching temperature. When the main power source and the auxiliary power source are switched based on the above, the driving of the second compressor, which is the main power source, is started after the switching, and the auxiliary power source is started after the switching. In stopping the drive of the first compressor, the second compressor that becomes the main power source after switching and the auxiliary power source after switching for the second predetermined time shorter than the first predetermined time. After controlling so that the drives of both of the first compressors overlap each other, the drive of the first compressor, which is the auxiliary power source, is controlled to be stopped after switching.

According to the present invention, it is possible to suppress fluctuations in the temperature of hot water or cold water generated when the main power source / auxiliary power source is switched due to a change in the outside air temperature during operation in which only the main power source is driven. It is possible to perform stable driving without impairing comfort.

Specifically, during the heating operation in which only the second compressor is driven as the main power source, the main power source and the auxiliary power source are switched based on the fact that the outside air temperature drops and reaches a predetermined switching temperature. (When the main power source is switched from the second compressor to the first compressor and the auxiliary power source is switched from the first compressor to the second compressor), the main power source after switching (first compressor) ), And the auxiliary power source (second compressor) after switching is stopped for a first predetermined time, the main power source after switching (first compressor) and after switching. After controlling so that the drives of both auxiliary power sources (second compressor) overlap, the main power source is controlled to stop the drive of the auxiliary power source (second compressor) after switching. / It is possible to suppress the decrease in the hot water temperature that occurs when the auxiliary power source is switched, and it is possible to perform stable heating operation with little temperature fluctuation from the target hot water temperature.

Further, when the main power source and the auxiliary power source are switched based on the fact that the outside air temperature rises and reaches a predetermined switching temperature during the heating operation in which only the first compressor is driven as the main power source ( When the main power source is switched from the first compressor to the second compressor and the auxiliary power source is switched from the second compressor to the first compressor), the main power source (second compressor) is driven after the switching. And to stop the drive of the auxiliary power source (first compressor) after switching, for a second predetermined time shorter than the first predetermined time, the main power source (second compressor) after switching and After controlling the drive of both auxiliary power sources (first compressor) after switching to overlap, control to stop the drive of the auxiliary power source (first compressor) after switching, or , The auxiliary power source (1st compressor) after switching so that the drives of both the main power source (2nd compressor) after switching and the auxiliary power source (1st compressor) after switching do not overlap. By controlling the drive to stop, it is possible to suppress the rise in hot water temperature that occurs when switching between the main power source and auxiliary power source, and it is possible to perform stable heating operation with little temperature fluctuation from the target hot water temperature. It can be done.

In addition, when the main power source and the auxiliary power source are switched based on the fact that the outside air temperature rises and reaches a predetermined switching temperature during the cooling operation in which only the second compressor is driven as the main power source. (When the main power source is switched from the second compressor to the first compressor and the auxiliary power source is switched from the first compressor to the second compressor), the main power source (first compressor) after switching In starting the drive and stopping the drive of the auxiliary power source (second compressor) after switching, the main power source (first compressor) after switching and the auxiliary power after switching for the first predetermined time. After controlling so that the drives of both sources (second compressor) overlap, the drive of the auxiliary power source (second compressor) after switching is controlled to be stopped, so that the main power source / auxiliary It is possible to suppress the rise in the chilled water temperature that occurs when the power source is switched, and it is possible to perform stable cooling operation with little temperature fluctuation from the target chilled water temperature.

In addition, when the main power source and the auxiliary power source are switched based on the fact that the outside air temperature drops and reaches a predetermined switching temperature during the cooling operation in which only the first compressor is driven as the main power source. (When the main power source is switched from the first compressor to the second compressor and the auxiliary power source is switched from the second compressor to the first compressor), the main power source (second compressor) after switching When starting the drive and stopping the drive of the auxiliary power source (first compressor) after switching, the main power source (second compressor) after switching is for a second predetermined time shorter than the first predetermined time. After controlling so that the drives of both the auxiliary power source (first compressor) after switching are overlapped, the driving of the auxiliary power source (first compressor) after switching is controlled to be stopped. Alternatively, the auxiliary power source after switching (first compressor) so that the drives of both the main power source (second compressor) after switching and the auxiliary power source (first compressor) after switching do not overlap. By controlling to stop the drive of the compressor, it is possible to suppress the decrease in the chilled water temperature that occurs when switching between the main power source and the auxiliary power source, and to perform stable cooling operation with little temperature fluctuation from the target chilled water temperature. Can be done.

The external block diagram which shows the main unit of the composite heat source heat pump apparatus which concerns on embodiment of this invention. The schematic block diagram which shows the whole structure of the compound heat source heat pump apparatus. The figure which shows the switching temperature of the main power source / auxiliary power source of a compound heat source heat pump apparatus. Explanatory drawing explaining operation at the time of heating operation. Explanatory drawing explaining operation at the time of cooling operation. A time chart explaining the transition over time when the outside air temperature drops during heating operation and switching between the main power source and the auxiliary power source occurs. A time chart explaining the transition over time when the outside air temperature rises during heating operation and switching between the main power source and the auxiliary power source occurs. A time chart explaining the transition over time when the outside air temperature rises during cooling operation and switching between the main power source and the auxiliary power source occurs. A time chart explaining the time course when the outside air temperature drops during cooling operation and switching between the main power source and the auxiliary power source occurs.

The configuration of the combined heat source heat pump device 1 according to the embodiment of the present invention will be described in detail with reference to the drawings as appropriate.
As shown in FIG. 1, the combined heat source heat pump device 1 includes a ground heat pump unit 4 including a first heat pump circuit 40 (see FIG. 2) and an air heat heat pump unit including a second heat pump circuit 50 (see FIG. 2). Has 5 and. Further, the combined heat source heat pump device 1 operates the load side circulation circuit 30 for circulating the load side circulating liquid L (for example, water or antifreeze) to the air conditioning terminal 36, the heat source side circulation circuit 20, and the combined heat source heat pump device 1. It has a control device 6 (61, 62) as a control means for controlling, and a remote controller 60 that sends a signal to the control device 6, and heats or cools the room in which the air conditioning terminal 36 is installed.

As shown in FIG. 2, the combined heat source heat pump device 1 according to the present embodiment heats or cools the load-side circulating liquid L on the air conditioning terminal 36 side by using a heat source different from the outside air, here, an underground heat source. The first load side heat exchanger 41 of the first heat pump circuit 40 and the second load side heat exchange of the second heat pump circuit 50 that heats or cools the load side circulating fluid L on the air conditioning terminal 36 side by using the outside air as a heat source. The first load side heat exchanger 41 is arranged on the upstream side of the second load side heat exchanger 51 with respect to the flow of the load side circulating liquid L circulating through the load side circulation circuit 30 with the device 51. .. The combined heat source heat pump device 1 can function as a heating device and a cooling device, and its components and operations will be described below.

The first heat pump circuit 40 includes a first compressor 43 having a variable rotation speed for compressing the first refrigerant C1, a first four-way valve 44, a first load side heat exchanger 41, a first expansion valve 45, and a first. 1 It is configured to include a heat source side heat exchanger 46 and a first refrigerant pipe 42 connecting them in a ring shape.

The first four-way valve 44 provided in the first refrigerant pipe 42 has a function as a switching valve for switching the flow direction of the first refrigerant C1 in the first heat pump circuit 40, and is discharged from the first compressor 43. A state in which the first refrigerant C1 is circulated in the order of the first load side heat exchanger 41, the first expansion valve 45, and the first heat source side heat exchanger 46 to form a flow path for returning to the first compressor 43 (heating operation). (Time state) and the first refrigerant C1 discharged from the first compressor 43 are circulated in the order of the first heat source side heat exchanger 46, the first expansion valve 45, and the first load side heat exchanger 41. 1 It is possible to switch to a state of forming a flow path for returning to the compressor 43 (a state during cooling operation).

Further, in the underground heat heat pump unit 4 shown in FIG. 2, reference numeral 42a is a first refrigerant discharge temperature sensor that detects the temperature of the first refrigerant C1 discharged from the first compressor 43, and reference numeral 42b is a first refrigerant discharge temperature sensor. No. 1 provided in the first refrigerant pipe 42 from the expansion valve 45 to the first heat source side heat exchanger 46, and detecting the temperature of the first refrigerant C1 on the low pressure side (during heating operation) or the high pressure side (during cooling operation). 1 Refrigerant temperature sensor.

The second heat pump circuit 50 includes a second compressor 53 with a variable rotation speed for compressing the second refrigerant C2, a second four-way valve 54, a second load side heat exchanger 51, a second expansion valve 55, and an air blower. It is configured to include an air heat exchanger 57 as a second heat source side heat exchanger that exchanges heat with the outside air sent by the operation of the fan 56, and a second refrigerant pipe 52 that connects them in a ring shape.

The second four-way valve 54 provided in the second refrigerant pipe 52 has a function as a switching valve for switching the flow direction of the second refrigerant C2 in the second heat pump circuit 50, and is discharged from the second compressor 53. A state in which the second refrigerant C2 is circulated in the order of the second load side heat exchanger 51, the second expansion valve 55, and the air heat exchanger 57 to form a flow path for returning to the second compressor 53 (state during heating operation). ) And the second refrigerant C2 discharged from the second compressor 53 are circulated in the order of the air heat exchanger 57, the second expansion valve 55, and the second load side heat exchanger 51, and returned to the second compressor 53. It is possible to switch to the state of forming a flow path (during cooling operation or defrosting operation).

Further, in the pneumatic heat pump unit 5 shown in FIG. 2, reference numeral 52a is a second refrigerant discharge temperature sensor that detects the temperature of the second refrigerant C2 discharged from the second compressor 53, and reference numeral 52b is a second refrigerant discharge temperature sensor. It is provided in the second refrigerant pipe 52 from the expansion valve 55 to the air heat exchanger 57, and detects the temperature of the second refrigerant C2 on the low pressure side (during heating operation) or the high pressure side (during defrosting operation or cooling operation). It is a second refrigerant temperature sensor, and reference numeral 52c is an outside air temperature sensor as an outside air temperature detecting means for detecting the outside air temperature.

As the refrigerant of the first heat pump circuit 40 and the second heat pump circuit 50, any HFC refrigerant such as R410A or R32 or any refrigerant such as carbon dioxide refrigerant can be used.

The first load side heat exchanger 41, the first heat source side heat exchanger 46, and the second load side heat exchanger 51 are composed of, for example, a plate type heat exchanger. In this plate-type heat exchanger, a plurality of heat transfer plates are laminated, and a refrigerant flow path through which a refrigerant flows and a fluid flow path through which a fluid such as a circulating fluid flows are alternately formed with each heat transfer plate as a boundary. ing.

The heat source side circulation circuit 20 serves as a heat source for heat exchange between the heat source side circulation pump 22 having a variable rotation speed, the first heat source side heat exchanger 46, and the first refrigerant C1 flowing through the first heat source side heat exchanger 46. The geothermal heat exchanger 23 installed (in the ground in this example) is connected in an annular shape by a heat source side pipe 21 as a heat medium pipe. The heat source side circulation pump 22 circulates the heat source side circulation liquid H (water or antifreeze liquid) in the heat source side piping 21 and stores the heat source side circulation liquid H to apply the pressure of the heat source side circulation circuit 20. A heat source side systurn 24 to be adjusted is provided.

In the load side circulation circuit 30, the first load side heat exchanger 41, the second load side heat exchanger 51, and the air conditioning terminal 36 as a load terminal such as a floor heating panel, a cold / hot water panel, and a fan coil are loaded. The side pipes 31 are connected in an annular shape in order from the upstream side. The load-side piping 31 is provided with a load-side circulation pump 32 that circulates the load-side circulating liquid L in the load-side circulation circuit 30, and each of the load-side piping 31 branched for each air conditioning terminal 36 is provided with a load-side circulation pump 32. Thermal valves 33 that control the supply of the load-side circulating liquid L to the air-conditioning terminal 36 by opening and closing are provided respectively, and the thermal valve 33 is set so that the room temperature in the room where the air-conditioning terminal 36 is installed becomes a predetermined temperature. The opening and closing is controlled, and although it is provided outside the air-conditioning terminal 36 in FIG. 2, it may be built in the air-conditioning terminal 36. Although two air-conditioning terminals 36 are provided in FIG. 2, the number or number of the air-conditioning terminals 36 may be one or three or more, and the quantity and specifications are not particularly limited.

Further, in the load-side circulation circuit 30 shown in FIG. 2, reference numeral 34 is a return that detects the temperature of the load-side circulating fluid L that is provided in the load-side piping 31 and flows into the first load-side heat exchanger 41 from the air conditioning terminal 36. It is a temperature sensor, and reference numeral 35 is a load side systurn that stores the load side circulation liquid L and adjusts the pressure of the load side circulation circuit 30.

The control device 6 includes a geothermal heat pump control device 61 that controls the operation of the heat source side circulation circuit 20, the load side circulation circuit 30, and the first heat pump circuit 40, and an air heat heat pump that controls the operation of the second heat pump circuit 50. It is provided with a control device 62. The control device 6 includes a storage unit that stores various data and programs, and a control unit that performs calculation / control processing. The control device 6 receives a signal from a temperature sensor such as an outside air temperature sensor 52c and a remote control 60, and receives a signal from the remote control 60. The operation of the combined heat source heat pump device 1 can be controlled.

Next, the geothermal heat pump control device 61 during the heating operation will be described. The geothermal heat pump control device 61 detects the temperature of the load-side circulating fluid L on the immediately upstream side of the first load-side heat exchanger 41. The rotation speed of the first compressor 43 is controlled according to the detected value of the return temperature sensor 34. In particular, in this example, the first compressor 43 is such that the return hot water temperature of the load-side circulating fluid L detected by the return temperature sensor 34 becomes a target hot water temperature set based on, for example, the set temperature of the remote controller 60. Controls the number of revolutions of.

Further, the geothermal heat pump control device 61 controls the valve opening degree of the first expansion valve 45 according to the refrigerant discharge temperature of the first refrigerant C1 detected by the first refrigerant discharge temperature sensor 42a. In particular, in this example, the first expansion is performed so that the refrigerant discharge temperature of the first refrigerant C1 detected by the first refrigerant discharge temperature sensor 42a becomes, for example, the control target refrigerant discharge temperature corresponding to the set temperature of the remote controller 60. The valve opening degree of the valve 45 is controlled.

Further, the geothermal heat pump control device 61 controls the rotation speed of the heat source side circulation pump 22 according to the temperature of the first refrigerant C1 detected by the first refrigerant temperature sensor 42b. In particular, in this example, the rotation speed of the heat source side circulation pump 22 is controlled so that the temperature of the first refrigerant C1 detected by the first refrigerant temperature sensor 42b becomes a substantially constant value.

Then, the geothermal heat pump control device 61 controls the rotation speed of the load-side circulation pump 32. In particular, in this example, when the heating operation is being performed, the rotation speed of the load-side circulation pump 32 is controlled so as to rotate at a constant speed (constant rotation speed).

Further, in the geothermal heat pump control device 61, the heat efficiency (heat sampling efficiency) of either the geothermal heat pump unit 4 or the air heat heat pump unit 5 is based on the outside air temperature detected by the outside air temperature sensor 52c during the heating operation. The one with the higher heat efficiency is set as the heat pump unit on the main side (priority side), and the one with the lower heat efficiency is set as the heat pump unit on the auxiliary side. In other words, the underground heat heat pump control device 61 uses the outside air temperature detected by the outside air temperature sensor 52c as a reference, and the first compressor 43 and the air heat heat pump unit 5 of the underground heat heat pump unit 4 (first heat pump circuit 40). One of the second compressors 53 of the (second heat pump circuit 50) is set as the main power source and the other as the auxiliary power source.

Here, switching between the main power source and the auxiliary power source during the heating operation will be described with reference to FIG. 3A. In addition, in FIG. 3A, the ones described as "geothermal HP main", "geothermal HP auxiliary", "air heat HP main", and "air heat HP auxiliary" are "No. 1", respectively. It can be read as "1 compressor 43 is the main power source", "the first compressor 43 is the auxiliary power source", "the second compressor 53 is the main power source", and "the second compressor 53 is the auxiliary power source". Is.

First, as a basic idea, when the outside air temperature is relatively low, such as in winter, there is a problem that the air heat exchanger 57 frosts due to endothermic heat from the outside air, so the first compressor 43 is the main power source. The second compressor 53 is used as an auxiliary power source. On the contrary, when the outside air temperature is not so low even in autumn, spring, and winter, the second compressor 53 is the main power source because the air heat exchanger 57 does not easily frost even if it absorbs heat from the outside air. The first compressor 43 is used as an auxiliary power source.

That is, in the present embodiment, when the outside air temperature detected by the outside air temperature sensor 52c is less than the predetermined switching temperature θ1 (for example, θ1 = 5 ° C.) when the heating operation is started, the first heat pump circuit 40 is the first. 1 The compressor 43 is used as the main power source, and the second compressor 53 of the second heat pump circuit 50 is used as the auxiliary power source to start the heating operation. When the outside air temperature detected by the outside air temperature sensor 52c is equal to or higher than the predetermined switching temperature θ1, the second compressor 53 of the second heat pump circuit 50 is used as the main power source, and the first compression of the first heat pump circuit 40 is performed. The heating operation is started by using the machine 43 as an auxiliary power source.

Then, in the present embodiment, when the outside air temperature changes after the heating operation is started as described above, the main power source and the auxiliary power source are appropriately replaced according to the degree of the change. That is, which of the first compressor 43 and the second compressor 53 is the main power source or the auxiliary power source is exchanged.

That is, as shown in FIG. 3A, after the first compressor 43 is used as the main power source and the second compressor 53 is used as the auxiliary power source (when the outside air temperature at the start of the heating operation is less than θ1), the heating operation is started. In addition, until the outside air temperature rises to the switching temperature of θ1 (5 ° C) or higher (less than 5 ° C), the first compressor 43 is used as the main power source and the second compressor 53 is used as the auxiliary power source. do. After that, when the outside air temperature rises to θ1 or more, the second compressor 53 is switched from the auxiliary power source to the main power source, and the first compressor 43 is switched from the main power source to the auxiliary power source.

On the contrary, after starting the heating operation with the second compressor 53 as the main power source and the first compressor 43 as the auxiliary power source (when the outside air temperature at the start of the heating operation is θ1 or more), FIG. 3A is shown. As described above, while the outside air temperature does not drop to less than θ2 (for example, θ2 = 2 ° C.) (for example, when the temperature is 2 ° C. or higher), the second compressor 53 is used as the main power source and the first compressor 43 is used as the auxiliary power source. And. After that, when the outside air temperature drops below θ2, the first compressor 43 is switched from the auxiliary power source to the main power source, and the second compressor 53 is switched from the main power source to the auxiliary power source.

That is, during the heating operation, as shown by the arrow in FIG. 3A, in the rising direction of the outside air temperature as described above, the switching temperature that serves as a delimiter for switching between the main power source and the auxiliary power source is set to θ1. In the direction of decrease in the outside air temperature, the switching temperature is changed to θ2 (= the switching behavior of the main power source / auxiliary power source has a hysteresis). The switching temperatures θ1 and θ2 are stored in advance in the storage unit of the control device 6.

As described above, when the outside air temperature changes and it is considered that it is more efficient to replace the allocation of the main power source and the auxiliary power source up to that point, the first compressor 43 and the second compressor 53 are used. The allocations are swapped, the compressor that was the main power source until then becomes the auxiliary power source, and the compressor that was the auxiliary power source becomes the main power source.

In the present embodiment, the underground heat heat pump control device 61 has been described as performing switching control between the main power source / auxiliary power source during the heating operation, but the pneumatic heat pump control device 62 is mainly used during the heating operation. It may control switching between the power source and the auxiliary power source, and the underground heat heat pump control device 61 and the air heat heat pump control device 62 are linked to each other as necessary to be the main power during the heating operation. It may control switching between the source / auxiliary power source.

Next, the air source heat pump control device 62 during the heating operation will be described. The air source heat pump control device 62 controls the rotation speed of the second compressor 53 according to the detection value of the return temperature sensor 34. In particular, in this example, the return hot water temperature of the load-side circulating fluid L detected by the return temperature sensor 34 becomes the target hot water temperature set based on, for example, the set temperature of the remote controller 60, so that the second compressor 53 is used. Control the number of revolutions. The air-heat pump control device 62 and the geothermal heat pump control device 61 control the target first compressor 43 or second compressor 53 while coordinating with each other as necessary.

Further, the air source heat pump control device 62 controls the valve opening degree of the second expansion valve 55 according to the refrigerant discharge temperature of the second refrigerant C2 detected by the second refrigerant discharge temperature sensor 52a. In particular, in this example, the second expansion is performed so that the refrigerant discharge temperature of the second refrigerant C2 detected by the second refrigerant discharge temperature sensor 52a becomes, for example, the control target refrigerant discharge temperature corresponding to the set temperature of the remote controller 60. The valve opening degree of the valve 55 is controlled. The air-heat pump control device 62 and the geothermal heat pump control device 61 control the target first expansion valve 45 or second expansion valve 55 while coordinating with each other as necessary.

Further, the air source heat pump control device 62 controls the rotation speed of the blower fan 56 according to the outside air temperature detected by the outside air temperature sensor 52c.

Next, the geothermal heat pump control device 61 during the cooling operation will be described, but the control method does not change because the load side circulation liquid L is only different from hot water or cold water as compared with the heating operation. The description of the rotation speed control of the first compressor 43, the opening degree control of the first expansion valve 45, the rotation speed control of the heat source side circulation pump 22, and the rotation speed control of the load side circulation pump 32) will be omitted. The same applies to the air source heat pump control device 62.

Here, the geothermal heat pump control device 61 has the heat efficiency (heat sampling efficiency) of either the geothermal heat pump unit 4 or the air heat heat pump unit 5 with reference to the outside air temperature detected by the outside air temperature sensor 52c during the cooling operation. ) Is high, and the one with higher heat efficiency is set as the heat pump unit on the main side (priority side), and the one with lower heat efficiency is set as the heat pump unit on the auxiliary side. In other words, the underground heat heat pump control device 61 uses the outside air temperature detected by the outside air temperature sensor 52c as a reference, and the first compressor 43 and the air heat heat pump unit 5 of the underground heat heat pump unit 4 (first heat pump circuit 40). One of the second compressors 53 of the (second heat pump circuit 50) is set as the main power source and the other as the auxiliary power source.

Here, switching between the main power source and the auxiliary power source during the cooling operation will be described with reference to FIG. 3 (b). In addition, in FIG. 3B, the ones described as "geothermal HP main", "geothermal HP auxiliary", "air heat HP main", and "air heat HP auxiliary" are "No. 1", respectively. It can be read as "1 compressor 43 is the main power source", "the first compressor 43 is the auxiliary power source", "the second compressor 53 is the main power source", and "the second compressor 53 is the auxiliary power source". Is.

First, as a basic idea, when the outside air temperature is not very high in spring or autumn, a large heat dissipation to the outside air can be expected, so the second compressor 53 that uses an air heat source is used as the main power source. The first compressor 43 using a medium heat source is used as an auxiliary power source. On the contrary, when the outside air temperature is relatively high in summer or the like, heat dissipation to the outside air cannot be expected so much, so the first compressor 43 using the underground heat source is used as the main power source, and the second using the air heat source. The compressor 53 is used as an auxiliary power source.

That is, in the present embodiment, when the outside air temperature detected by the outside air temperature sensor 52c is less than the predetermined switching temperature θ3 (for example, θ3 = 33 ° C.) when the cooling operation is started, the second heat pump circuit 50 is the second. 2 The compressor 53 is used as the main power source, and the first compressor 43 of the first heat pump circuit 40 is used as the auxiliary power source to start the cooling operation. When the outside air temperature detected by the outside air temperature sensor 52c is equal to or higher than the predetermined switching temperature θ3, the first compressor 43 of the first heat pump circuit 40 is used as the main power source, and the second compression of the second heat pump circuit 50 is performed. Using the machine 53 as an auxiliary power source, the cooling operation is started.

Then, in the present embodiment, when the outside air temperature changes after the cooling operation is started as described above, the main power source and the auxiliary power source are appropriately replaced according to the degree of the change. That is, which of the first compressor 43 and the second compressor 53 is the main power source or the auxiliary power source is exchanged.

That is, as shown in FIG. 3B after the second compressor 53 starts the cooling operation as the main power source and the first compressor 43 uses the auxiliary power source (when the outside air temperature at the start of the cooling operation is less than θ3). The second compressor 53 is used as the main power source and the first compressor 43 is used as the auxiliary power source until the outside air temperature rises to the switching temperature of θ3 (33 ° C.) or higher (when the temperature is lower than 33 ° C.). do. After that, when the outside air temperature rises to θ3 or higher, the first compressor 43 is switched from the auxiliary power source to the main power source, and the second compressor 53 is switched from the main power source to the auxiliary power source.

On the contrary, after starting the cooling operation with the first compressor 43 as the main power source and the second compressor 53 as the auxiliary power source (when the outside air temperature at the start of the cooling operation is θ3 or more), it is shown in FIG. 3 (b). As described above, while the outside air temperature does not decrease to less than θ4 (for example, θ4 = 30 ° C.) (when the temperature is 30 ° C. or higher), the first compressor 43 is used as the main power source and the second compressor 53 is used as the auxiliary power source. And. After that, when the outside air temperature drops below θ4, the second compressor 53 is switched from the auxiliary power source to the main power source, and the first compressor 43 is switched from the main power source to the auxiliary power source.

That is, during the cooling operation, as shown by the arrow in FIG. 3B, in the rising direction of the outside air temperature as described above, the switching temperature that serves as a delimiter for switching between the main power source and the auxiliary power source is set to θ3, while the switching temperature is set to θ3. In the direction of decrease in the outside air temperature, the switching temperature is changed to θ4 (= the switching behavior of the main power source / auxiliary power source has a hysteresis). The switching temperatures θ3 and θ4 are stored in advance in the storage unit of the control device 6.

As described above, when the outside air temperature changes and it is considered that it is more efficient to replace the allocation of the main power source and the auxiliary power source up to that point, the first compressor 43 and the second compressor 53 are used. The allocations are swapped, the compressor that was the main power source until then becomes the auxiliary power source, and the compressor that was the auxiliary power source becomes the main power source.

In the present embodiment, the geothermal heat pump control device 61 has been described as performing switching control between the main power source / auxiliary power source during the cooling operation, but the pneumatic heat pump control device 62 is mainly used during the cooling operation. The power source / auxiliary power source may be switched and controlled, and the geothermal heat pump control device 61 and the air heat heat pump control device 62 are linked to each other as necessary to be the main power during cooling operation. It may control switching between the source / auxiliary power source.

Next, the operation of the combined heat source heat pump device 1 shown in FIGS. 1 and 2 during the heating operation will be described with reference to FIG. The heating operation for generating hot water supplied to the air conditioning terminal 36 (hereinafter, appropriately, the load-side circulating fluid L during the heating operation is referred to as “hot water”) is performed by either the first heat pump circuit 40 or the second heat pump circuit 50. There are cases where both the first heat pump circuit 40 and the second heat pump circuit 50 are operated, but here, both the first heat pump circuit 40 and the second heat pump circuit 50 are operated. The case of doing this will be described. The arrows in FIG. 4 indicate the flow direction of the refrigerant and the circulating fluid.

When the remote control 60 instructs the air-conditioned terminal 36 to heat the room as an air-conditioned space, the control device 6 first uses the outside air temperature as a reference to the first compressor 43 of the ground heat heat pump unit 4 and air heat. Of the second compressor 53 of the heat pump device 5, one is set as the main power source and the other is set as the auxiliary power source.

Specifically, if the outside air temperature detected by the outside air temperature sensor 52c is equal to or higher than the predetermined switching temperature θ1 (for example, 5 ° C.), it is determined that the air heat heat pump unit 5 has higher heat sampling efficiency, and the second compression is performed. If the machine 53 is set as the main power source and the first compressor 43 is set as the auxiliary power source, and the outside air temperature detected by the outside air temperature sensor 52c is less than the predetermined switching temperature θ1 (for example, 5 ° C.), the ground is ground. It is determined that the medium heat heat pump unit 4 has higher heat sampling efficiency, and the first compressor 43 is set as the main power source and the second compressor 53 is set as the auxiliary power source.

Then, the control device 6 switches the flow path of the first four-way valve 44 and the second four-way valve 54 so as to be in the state during the heating operation, and the first compressor 43, the first expansion valve 45, and the heat source side circulation pump 22. , The second compressor 53, the second expansion valve 55, the blower fan 56, and the load side circulation pump 32 are driven to start the heating operation. At this time, the thermal valve 33 is also opened.

During the heating operation, in the first heat pump circuit 40, the high-temperature, high-pressure gaseous first refrigerant C1 compressed by the first compressor 43 is discharged from the first compressor 43, and the first refrigerant C1 serves as a condenser. In the functioning first load side heat exchanger 41, heat is exchanged with the hot water flowing through the load side circulation circuit 30, heat is released to the hot water, and the heat is changed to a high-pressure refrigerant in a gas-liquid mixed state while heating. Then, the first refrigerant C1 in this state is decompressed by the first expansion valve 45 to become a low-pressure refrigerant and easily evaporates, and in the first heat source side heat exchanger 46 functioning as an evaporator, the heat source side circulation circuit. It exchanges heat with the heat source side circulating liquid H flowing through 20 and absorbs heat from the heat source side circulating liquid H to become a low-temperature, low-pressure gaseous first refrigerant C1 and returns to the first compressor 43 again.

On the other hand, in the second heat pump circuit 50, the high-temperature, high-pressure gaseous second refrigerant C2 compressed by the second compressor 53 is discharged from the second compressor 53, and the second refrigerant C2 functions as a condenser. 2 The load side heat exchanger 51 exchanges heat with the hot water flowing through the load side circulation circuit 30, releases heat to the hot water, and changes to a high-pressure refrigerant in a gas-liquid mixed state while heating. Then, the second refrigerant C2 in this state is decompressed by the second expansion valve 55 to become a low-pressure refrigerant and easily evaporates, and in the air heat exchanger 57 functioning as an evaporator, the blower fan 56 operates to send the second refrigerant C2. It exchanges heat with the outside air, absorbs heat from the outside air, becomes a low-temperature, low-pressure gaseous second refrigerant C2, and returns to the second compressor 53 again.

In the heat source side circulation circuit 20, the underground heat is collected by the underground heat exchanger 23, and the heat source side circulating liquid H carrying the heat is driven by the heat source side circulation pump 22 to drive the first heat source side heat exchanger 46. Is supplied to. Then, heat exchange is performed between the first refrigerant C1 and the heat source side circulating fluid H in the first heat source side heat exchanger 46, and the geothermal heat collected by the geothermal heat exchanger 23 is on the first refrigerant C1 side. The first refrigerant C1 is heated and evaporated.

In the load side circulation circuit 30, the low temperature hot water flowing into the first load side heat exchanger 41 by the drive of the load side circulation pump 32 driven at a constant rotation speed is the first load side heat exchange that functions as a condenser. After being heated by heat exchange with the first refrigerant C1 in the vessel 41, the hot water heated by heat exchange with the second refrigerant C2 in the second load side heat exchanger 51 functioning as a condenser is heated. After that, the hot water supplied to the air conditioner terminal 36 and used for indoor heating, and the hot water whose temperature has dropped due to heat dissipation when flowing through the air conditioner terminal 36 returns to the first load side heat exchanger 41 again.

Next, the operation of the combined heat source heat pump device 1 shown in FIGS. 1 and 2 during the cooling operation will be described with reference to FIG. The cooling operation for generating the cold water supplied to the air conditioning terminal 36 (hereinafter, appropriately, the load-side circulating liquid L during the cooling operation is referred to as “cold water”) is performed by either the first heat pump circuit 40 or the second heat pump circuit 50. There are cases where both the first heat pump circuit 40 and the second heat pump circuit 50 are operated, but here, both the first heat pump circuit 40 and the second heat pump circuit 50 are operated. The case of doing this will be described. The arrows in FIG. 5 indicate the flow direction of the refrigerant and the circulating fluid.

When the remote control 60 instructs the air-conditioned terminal 36 to cool the room as an air-conditioned space, the control device 6 first uses the outside air temperature as a reference to the first compressor 43 of the ground heat heat pump unit 4 and air heat. Of the second compressor 53 of the heat pump device 5, one is set as the main power source and the other is set as the auxiliary power source.

Specifically, if the outside air temperature detected by the outside air temperature sensor 52c is equal to or higher than the predetermined switching temperature θ3 (for example, 33 ° C.), it is determined that the underground heat heat pump unit 4 has higher heat sampling efficiency, and the first If the compressor 43 is set as the main power source and the second compressor 53 is set as the auxiliary power source, and the outside air temperature detected by the outside air temperature sensor 52c is less than the predetermined switching temperature θ3 (for example, 33 ° C.), It is determined that the pneumatic heat pump unit 5 has higher heat collection efficiency, and the second compressor 53 is set as the main power source and the first compressor 43 is set as the auxiliary power source.

Then, the control device 6 switches the flow path so that the first four-way valve 44 and the second four-way valve 54 are in the state during the cooling operation, and the first compressor 43, the first expansion valve 45, and the heat source side circulation pump 22 are switched. , The second compressor 53, the second expansion valve 55, the blower fan 56, and the load side circulation pump 32 are driven to start the cooling operation. At this time, the thermal valve 33 is also opened.

During the cooling operation, in the first heat pump circuit 40, the high-temperature, high-pressure gaseous first refrigerant C1 compressed by the first compressor 43 is discharged from the first compressor 43, and the first refrigerant C1 serves as a condenser. In the functioning first heat source side heat exchanger 46, heat is exchanged with the heat source side circulation liquid H flowing through the heat source side circulation circuit 20 to release heat to the heat source side circulation liquid H to cool the mixture in a gas-liquid state. It changes to a high pressure refrigerant. Then, the first refrigerant C1 in this state is decompressed by the first expansion valve 45 to become a low-pressure refrigerant and easily evaporates, and in the first load side heat exchanger 41 functioning as an evaporator, the load side circulation circuit. It exchanges heat with the cold water flowing through 30, absorbs heat from the cold water, becomes a low-temperature, low-pressure gaseous first refrigerant C1, and returns to the first compressor 43 again.

On the other hand, in the second heat pump circuit 50, the high-temperature, high-pressure gaseous second refrigerant C2 compressed by the second compressor 53 is discharged from the second compressor 53, and the second refrigerant C2 is air that functions as a condenser. The heat exchanger 57 exchanges heat with the outside air sent by the operation of the blower fan 56, releases heat from the outside air, cools the outside air, and changes to a high-pressure refrigerant in a gas-liquid mixed state. Then, the second refrigerant C2 in this state is decompressed by the second expansion valve 55 to become a low-pressure refrigerant and easily evaporates, and in the second load side heat exchanger 51 functioning as an evaporator, the load side circulation circuit. It exchanges heat with the cold water flowing through 30, absorbs heat from the cold water, becomes a low-temperature, low-pressure gaseous second refrigerant C2, and returns to the second compressor 53 again.

In the load-side circulation circuit 30, the cold water that has flowed into the first load-side heat exchanger 41 due to the drive of the load-side circulation pump 32 that is driven at a constant rotation speed is the first load-side heat exchanger 41 that functions as an evaporator. In the second load side heat exchanger 51 that functions as an evaporator, the cold water that has been heat exchanged with the second refrigerant C2 and further cooled and cooled is subsequently cooled by heat exchange with the first refrigerant C1. The cold water that is supplied to the air conditioner terminal 36 and used for indoor cooling, absorbs heat when flowing through the air conditioner terminal 36, and whose temperature rises, returns to the first load side heat exchanger 41 again.

Next, as a characteristic operation, regarding the operation of the scene where switching between the main power source and the auxiliary power source occurs during the heating operation or the cooling operation in which only the compressor set as the main power source is driven. This will be described with reference to the time charts of FIGS. 6 to 9.

FIG. 6 shows a scene in which the outside air temperature drops and switching between the main power source and the auxiliary power source occurs during the heating operation, and the hot water temperature detected by the return temperature sensor 34 in the present embodiment is the first. The time course of the number of revolutions of the compressor 43 and the number of revolutions of the second compressor 53 is shown by a solid line, the hot water temperature detected by the return temperature sensor 34 in the comparative example, the number of revolutions of the first compressor 43, and the second compressor. The time course of the number of rotations of 53 is shown by a one-point chain line. The time t1 represents the time after a predetermined time has elapsed since the heating operation was started.

At time t1, the outside air temperature detected by the outside air temperature sensor 52c is set to the switching temperature θ1 (5 ° C.) or higher, the second compressor 53 is set as the main power source, and the first compressor 43 is set as the auxiliary power source. The heating operation is performed by driving only the second compressor 53 of the main power source while the drive of the first compressor 43 of the auxiliary power source is stopped, and the second is performed in the time t1 to t2. The compressor 53 is driven at 60 rps to maintain the hot water temperature at the target hot water temperature (here, 30 ° C.).

Then, as the time t2 approaches, the outside air temperature detected by the outside air temperature sensor 52c gradually decreases, and at the time t2, the outside air temperature changes in the direction of increasing the load and reaches the switching temperature θ2, that is, the outside air. When the external load increases due to the decrease in temperature and the outside air temperature decreases and reaches the switching temperature θ2 (when the switching temperature becomes less than θ2), the control device 6 satisfies the switching condition of the main power source / auxiliary power source. The setting of the first compressor 43 is switched from the auxiliary power source to the main power source, and the setting of the second compressor 53 is switched from the main power source to the auxiliary power source.

At this time, the control device 6 starts driving the first compressor 43, which became the main power source after the switching, from the stopped state, and continues driving the second compressor 53, which became the auxiliary power source after the switching. During the first predetermined time (time t2 to t3) during the time t2), both the first compressor 43 which became the main power source after the switching and the second compressor 53 which became the auxiliary power source after the switching were driven. The state, that is, the drive of both the first compressor 43 and the second compressor 53 is controlled to overlap (see the solid line showing the present embodiment). At the start of driving the first compressor 43, the control device 6 sets 60 rps, which is the same as the rotation speed of the second compressor 53, which has been the main power source until then, as the indicated rotation speed of the first compressor 43. The first compressor 43 is controlled to be driven at 60 rps.

During the first predetermined time (time t2 to t3), the hot water temperature detected by the return temperature sensor 34 drops from the target hot water temperature due to the increase in the external load accompanying the decrease in the outside air temperature, but the first Since both the compressor 43 and the second compressor 53 are driven by overlapping, the output is increased, the output and the load are balanced, and the hot water temperature does not fluctuate (undershoot) significantly (this). See solid line showing embodiments.).

Then, at the time when the first predetermined time has elapsed (time t3), the control device 6 stops driving the second compressor 53 which has become an auxiliary power source after switching, and after the time t3, the first compressor Only 43 is driven at 60 rps to maintain the hot water temperature at the target hot water temperature (see the solid line showing this embodiment).

As described above, in the present embodiment, the main power source and the auxiliary power are based on the fact that the outside air temperature drops and reaches the switching temperature θ2 during the heating operation in which only the second compressor 53 is driven as the main power source. When switching from the source (when the main power source is switched from the second compressor 53 to the first compressor 43 and the auxiliary power source is switched from the first compressor 43 to the second compressor 53), after switching. In starting the driving of the main power source (first compressor 43) and stopping the driving of the auxiliary power source (second compressor 53) after switching, during the first predetermined time (time t2 to t3), After controlling so that the drives of both the main power source (first compressor 43) after switching and the auxiliary power source (second compressor 53) after switching overlap each other, the auxiliary power source after switching (second). The drive of the compressor 53) is controlled to be stopped (time t3).

During the heating operation, when the external load increases as the outside air temperature decreases, the hot water temperature tends to decrease. In this case, when switching between the main power source and the auxiliary power source, the main power source (first compressor 43) after switching is started from the stopped state as shown in the comparative example shown by the one-point chain line in FIG. At the same time, if the drive of the auxiliary power source (second compressor 53) after switching is stopped (see time t2), the output will be insufficient and the temperature of the hot water will fluctuate greatly from the target hot water temperature (under). It takes time to adjust the temperature to the target hot water temperature (see the hot water temperature after time t2), and stable operation cannot be performed and comfort is impaired. On the other hand, in the present embodiment, the auxiliary power source after switching (second compressor 53) is not immediately stopped, but the main power source after switching (first compressor 43) and the auxiliary power source after switching (second compressor 53) are not stopped immediately. By providing a time (first predetermined time) in which both of the second compressors 53) are in the driving state, it is possible to suppress a decrease in the hot water temperature that occurs when switching between the main power source and the auxiliary power source, and the target hot water temperature can be suppressed. It is possible to perform stable heating operation with little temperature fluctuation from.

Next, the time chart of FIG. 7 will be described. FIG. 7 shows a scene in which the outside air temperature rises and switching between the main power source and the auxiliary power source occurs during the heating operation, and the hot water temperature detected by the return temperature sensor 34 in the present embodiment is the first. The time course of the number of revolutions of the compressor 43 and the number of revolutions of the second compressor 53 is shown by a solid line, the hot water temperature detected by the return temperature sensor 34 in the comparative example, the number of revolutions of the first compressor 43, and the second compressor. The time course of the number of rotations of 53 is shown by a one-point chain line. The time t11 represents the time after a predetermined time has elapsed since the heating operation was started.

At time t11, the outside air temperature detected by the outside air temperature sensor 52c is less than the switching temperature θ1 (5 ° C.), the first compressor 43 is set as the main power source, and the second compressor 53 is set as the auxiliary power source. The heating operation is performed by driving only the first compressor 43 of the main power source while the drive of the second compressor 53 of the auxiliary power source is stopped, and the first is performed at time t11 to t12. The compressor 43 is driven at 60 rps, and the hot water temperature is maintained at the target hot water temperature (here, 30 ° C.).

Then, as the time t12 approaches, the outside air temperature detected by the outside air temperature sensor 52c gradually rises, and at the time t12, the outside air temperature changes in the direction in which the load decreases and reaches the switching temperature θ1, that is, the outside air. When the external load decreases due to the rise in temperature and the outside air temperature rises and reaches the switching temperature θ1 (when the switching temperature becomes θ1 or higher), the control device 6 satisfies the switching condition of the main power source / auxiliary power source. The setting of the second compressor 53 is switched from the auxiliary power source to the main power source, and the setting of the first compressor 43 is switched from the main power source to the auxiliary power source.

At this time, the control device 6 starts driving the second compressor 53, which has become the main power source after switching, from the stopped state, and at the same time, stops driving the first compressor 43, which has become the auxiliary power source after switching. (Time t12), that is, the drive of the first compressor 43, which is the auxiliary power source after switching, is stopped so that the drives of both the first compressor 43 and the second compressor 53 do not overlap (this implementation). See the solid line showing the morphology.) At the start of driving the second compressor 53, the control device 6 sets 60 rps, which is the same as the rotation speed of the first compressor 43, which has been the main power source until then, as the indicated rotation speed of the second compressor 53. The second compressor 53 is controlled to be driven at 60 rps.

Then, at the time t12, the drive of the second compressor 53 was started and at the same time the drive of the first compressor 43 was stopped, so that the hot water temperature detected by the return temperature sensor 34 at the time t12 to t13 was increased. Although the temperature drops from the target hot water temperature due to the decrease in output, the output and load are balanced due to the decrease in external load due to the increase in outside air temperature, and the hot water temperature does not fluctuate significantly (solid line showing this embodiment). reference.). After the time t13, only the second compressor 53 is driven at 60 rps to maintain the hot water temperature at the target hot water temperature (see the solid line showing the present embodiment).

As described above, in the present embodiment, the main power source and the auxiliary power are based on the fact that the outside air temperature rises and reaches the switching temperature θ1 during the heating operation in which only the first compressor 43 is driven as the main power source. When switching from the source (when the main power source is switched from the first compressor 43 to the second compressor 53 and the auxiliary power source is switched from the second compressor 53 to the first compressor 43), after switching. When starting the drive of the main power source (second compressor 53) and stopping the drive of the auxiliary power source (first compressor 43) after switching, the main power source (second compressor 53) after switching is stopped. And so that the drive of both the auxiliary power source (first compressor 43) after switching does not overlap, the drive of the auxiliary power source (first compressor 43) after switching is controlled to be stopped. There is.

During the heating operation, when the external load decreases as the outside air temperature rises, the hot water temperature tends to rise. In this case, when switching between the main power source and the auxiliary power source, as shown in the comparative example shown by the one-point chain line in FIG. 7, the main power source after switching (time t12 to t13) during the first predetermined time (time t12 to t13). 2 After controlling the drive of both the compressor 53) and the auxiliary power source (first compressor 43) after switching so as to overlap, the drive of the auxiliary power source (first compressor 43) after switching is stopped. (Refer to time t13.) If the control is performed so that the output becomes excessive, the temperature of the hot water greatly fluctuates (overshoots) from the target hot water temperature, and it takes time to adjust the temperature to the target hot water temperature. (Refer to the hot water temperature after time t12.) Stable operation cannot be performed and comfort is impaired. On the other hand, in the present embodiment, the driving of the main power source (second compressor 53) after switching is started, and at the same time, the driving of the auxiliary power source (first compressor 43) after switching is stopped. As a result, it is possible to suppress the rise in hot water temperature that occurs when switching between the main power source and the auxiliary power source, and it is possible to perform stable heating operation with little temperature fluctuation from the target hot water temperature.

Next, the time chart of FIG. 8 will be described. FIG. 8 shows a scene in which the outside air temperature rises and switching between the main power source and the auxiliary power source occurs during the cooling operation, and the cold water temperature detected by the return temperature sensor 34 in the present embodiment is the first. The time course of the number of revolutions of the compressor 43 and the number of revolutions of the second compressor 53 is shown by a solid line, and the cold water temperature detected by the return temperature sensor 34 in the comparative example, the number of revolutions of the first compressor 43, and the second compressor. The time course of the number of rotations of 53 is shown by a one-point chain line. The time t21 represents the time after a predetermined time has elapsed since the cooling operation was started.

At time t21, the outside air temperature detected by the outside air temperature sensor 52c is less than the switching temperature θ3 (33 ° C.), the second compressor 53 is set as the main power source, and the first compressor 43 is set as the auxiliary power source. The cooling operation is performed by driving only the second compressor 53 of the main power source while the drive of the first compressor 43 of the auxiliary power source is stopped, and the second is performed at time t21 to t22. The compressor 53 is driven at 60 rps to maintain the chilled water temperature at the target chilled water temperature (here, 20 ° C.).

Then, as the time t22 approaches, the outside air temperature detected by the outside air temperature sensor 52c gradually rises, and at the time t22, the outside air temperature changes in the direction of increasing the load and reaches the switching temperature θ3, that is, the outside air. When the external load increases due to the rise in temperature and the outside air temperature rises and reaches the switching temperature θ3 (when the switching temperature becomes θ3 or higher), the control device 6 satisfies the switching condition of the main power source / auxiliary power source. The setting of the first compressor 43 is switched from the auxiliary power source to the main power source, and the setting of the second compressor 53 is switched from the main power source to the auxiliary power source.

At this time, the control device 6 starts driving the first compressor 43, which became the main power source after the switching, from the stopped state, and continues driving the second compressor 53, which became the auxiliary power source after the switching. During the first predetermined time (time t22 to t23), both the first compressor 43, which became the main power source after switching, and the second compressor 53, which became the auxiliary power source after switching, were driven. The state, that is, the drive of both the first compressor 43 and the second compressor 53 is controlled to overlap (see the solid line showing the present embodiment). At the start of driving the first compressor 43, the control device 6 sets 60 rps, which is the same as the rotation speed of the second compressor 53, which has been the main power source until then, as the indicated rotation speed of the first compressor 43. The first compressor 43 is controlled to be driven at 60 rps.

During the first predetermined time (time t22 to t23), the chilled water temperature detected by the return temperature sensor 34 rises from the target chilled water temperature due to the increase in the external load accompanying the rise in the outside air temperature. Since both the compressor 43 and the second compressor 53 are driven by overlapping, the output is increased, the output and the load are balanced, and the hot water temperature does not fluctuate (overshoot) significantly (this). See solid line showing embodiments.).

Then, at the time when the first predetermined time has elapsed (time t23), the control device 6 stops driving the second compressor 53 which has become an auxiliary power source after switching, and after the time t23, the first compressor Only 43 is driven at 60 rps to maintain the chilled water temperature at the target chilled water temperature (see solid line showing this embodiment).

As described above, in the present embodiment, the main power source and the auxiliary power are based on the fact that the outside air temperature rises and reaches the switching temperature θ3 during the cooling operation in which only the second compressor 53 is driven as the main power source. When switching from the source (when the main power source is switched from the second compressor 53 to the first compressor 43 and the auxiliary power source is switched from the first compressor 43 to the second compressor 53), after switching. In starting the driving of the main power source (first compressor 43) and stopping the driving of the auxiliary power source (second compressor 53) after switching, during the first predetermined time (time t22 to t23), After controlling so that the drives of both the main power source (first compressor 43) after switching and the auxiliary power source (second compressor 53) after switching overlap each other, the auxiliary power source after switching (second). The drive of the compressor 53) is controlled to be stopped (time t23).

During the cooling operation, if the external load increases as the outside air temperature rises, the chilled water temperature tends to rise. In this case, when switching between the main power source and the auxiliary power source, the main power source (first compressor 43) after switching is started from the stopped state as in the comparative example shown by the one-point chain line in FIG. At the same time, if the drive of the auxiliary power source (second compressor 53) after switching is stopped (see time t22), the output is insufficient and the temperature of the chilled water fluctuates greatly from the target chilled water temperature (over). It takes time to adjust the temperature to the target chilled water temperature (see the chilled water temperature after time t22), and stable operation cannot be performed and comfort is impaired. On the other hand, in the present embodiment, the auxiliary power source after switching (second compressor 53) is not immediately stopped, but the main power source after switching (first compressor 43) and the auxiliary power source after switching (second compressor 53) are not stopped immediately. By providing a time (first predetermined time) in which both of the second compressors 53) are in the driving state, it is possible to suppress an increase in the chilled water temperature that occurs when switching between the main power source and the auxiliary power source, and the target chilled water temperature. It is possible to perform stable cooling operation with little temperature fluctuation from the air.

Next, the time chart of FIG. 9 will be described. FIG. 9 shows a scene in which the outside air temperature drops and switching between the main power source and the auxiliary power source occurs during the cooling operation, and the cold water temperature detected by the return temperature sensor 34 in the present embodiment is the first. The time course of the number of revolutions of the compressor 43 and the number of revolutions of the second compressor 53 is shown by a solid line, and the cold water temperature detected by the return temperature sensor 34 in the comparative example, the number of revolutions of the first compressor 43, and the second compressor. The time course of the number of rotations of 53 is shown by a one-point chain line. The time t31 represents the time after a predetermined time has elapsed since the cooling operation was started.

At time t31, the outside air temperature detected by the outside air temperature sensor 52c is set to the switching temperature θ3 (33 ° C.) or higher, the first compressor 43 is set as the main power source, and the second compressor 53 is set as the auxiliary power source. The cooling operation is performed by driving only the first compressor 43 of the main power source while the drive of the second compressor 53 of the auxiliary power source is stopped, and the first is performed at time t31 to t32. The compressor 43 is driven at 60 rps, and the chilled water temperature is maintained at the target chilled water temperature (here, 20 ° C.).

Then, as the time t32 approaches, the outside air temperature detected by the outside air temperature sensor 52c gradually decreases, and at the time t32, the outside air temperature changes in the direction in which the load decreases and reaches the switching temperature θ4, that is, the outside air. When the external load decreases due to the decrease in temperature and the outside air temperature decreases and reaches the switching temperature θ4 (when the switching temperature becomes less than θ4), the control device 6 satisfies the switching condition of the main power source / auxiliary power source. The setting of the second compressor 53 is switched from the auxiliary power source to the main power source, and the setting of the first compressor 43 is switched from the main power source to the auxiliary power source.

At this time, the control device 6 starts driving the second compressor 53, which has become the main power source after switching, from the stopped state, and at the same time, stops driving the first compressor 43, which has become the auxiliary power source after switching. (Time t32), that is, the drive of the first compressor 43, which is the auxiliary power source after switching, is stopped so that the drives of both the first compressor 43 and the second compressor 53 do not overlap (this implementation). See the solid line showing the morphology.) At the start of driving the second compressor 53, the control device 6 sets 60 rps, which is the same as the rotation speed of the first compressor 43, which has been the main power source until then, as the indicated rotation speed of the second compressor 53. The second compressor 53 is controlled to be driven at 60 rps.

Then, at the time t32, the drive of the second compressor 53 was started and at the same time the drive of the first compressor 43 was stopped, so that the cold water temperature detected by the return temperature sensor 34 at the time t32 to t33 was determined. Although the temperature drops from the target chilled water temperature due to the decrease in output, the output and load are balanced due to the decrease in external load due to the decrease in outside air temperature, and the chilled water temperature does not fluctuate significantly (solid line showing this embodiment). reference.). After the time t33, only the second compressor 53 is driven at 60 rps to maintain the chilled water temperature at the target chilled water temperature (see the solid line showing the present embodiment).

As described above, in the present embodiment, the main power source and the auxiliary power are based on the fact that the outside air temperature drops and reaches the switching temperature θ4 during the cooling operation in which only the first compressor 43 is driven as the main power source. When switching from the source (when the main power source is switched from the first compressor 43 to the second compressor 53 and the auxiliary power source is switched from the second compressor 53 to the first compressor 43), after switching. When starting the drive of the main power source (second compressor 53) and stopping the drive of the auxiliary power source (first compressor 43) after switching, the main power source (second compressor 53) after switching is stopped. And so that the drive of both the auxiliary power source (first compressor 43) after switching does not overlap, the drive of the auxiliary power source (first compressor 43) after switching is controlled to be stopped. There is.

During the cooling operation, when the external load decreases as the outside air temperature decreases, the chilled water temperature tends to decrease. In this case, when switching between the main power source and the auxiliary power source, as shown in the comparative example shown by the one-point chain line in FIG. 9, the main power source after switching (time t32 to t33) during the first predetermined time (time t32 to t33). 2 After controlling the drive of both the compressor 53) and the auxiliary power source (first compressor 43) after switching so as to overlap, the drive of the auxiliary power source (first compressor 43) after switching is stopped. (Refer to time t13.) If the control is performed so that the output becomes excessive, the temperature of the chilled water greatly fluctuates (undershoots) from the target chilled water temperature, and it takes time to adjust the temperature to the target chilled water temperature. (Refer to the cold water temperature after the time t32.) Stable operation cannot be performed and comfort is impaired. On the other hand, in the present embodiment, the driving of the main power source (second compressor 53) after switching is started, and at the same time, the driving of the auxiliary power source (first compressor 43) after switching is stopped. As a result, it is possible to suppress the decrease in chilled water temperature that occurs when switching between the main power source and the auxiliary power source, and it is possible to perform stable cooling operation with little temperature fluctuation from the target chilled water temperature.

The present invention is not limited to the one embodiment described above, and in the present embodiment, when the outside air temperature reaches the switching temperature (θ1, θ2, θ3, θ4), this is used as an opportunity. The control device 6 is used to switch the main power source / auxiliary power source in the first compressor 43 and the second compressor 53, but it is necessary to switch the main power source / auxiliary power source due to a change in the outside air temperature. Even if it is determined that the actual switching operation is not performed immediately, the switching is performed when the state in which the determination is necessary continues for a predetermined period (for example, 30 minutes). good. This excludes momentary fluctuations in the outside air temperature due to accidental factors, such as when the outside air temperature rises for a short time due to a gust and then falls immediately, so that switching is performed only in response to the tendency of changes in the outside air temperature. This is to ensure the operational stability of the first compressor 43 and the second compressor 53.

Further, in the present embodiment, as shown in FIG. 7, during the heating operation in which only the first compressor 43 is driven as the main power source, the outside air temperature rises and the main power source / auxiliary power source can be switched. When it occurs, the auxiliary power source after switching (second compressor 53) and the auxiliary power source after switching (first compressor 43) do not overlap each other so that the drives of both the main power source (second compressor 53) and the auxiliary power source (first compressor 43) after switching do not overlap. The drive of the first compressor 43) was stopped, but during the heating operation in which only the second compressor 53 was driven as the main power source, the outside air temperature rose and the main power source / auxiliary power source was switched. When ~ T3) ”, the main power source after switching (second compressor 53) and the auxiliary power source after switching (first compressor 43) during the second predetermined time shorter than the first predetermined time. After controlling so that the drives of both are overlapped with each other, the drive of the auxiliary power source (first compressor 43) after switching may be stopped. By doing so, it is possible to suppress fluctuations in the hot water temperature as compared with the case where the drives of the first compressor 43 and the second compressor 53 are overlapped during the first predetermined time (time t2 to t3). , Stable operation can be realized. However, when setting the second predetermined time, it is desirable to set a time so that the fluctuation of the hot water temperature with respect to the target hot water temperature does not become large by conducting an experiment in advance.

Further, in the present embodiment, as shown in FIG. 9, during the cooling operation in which only the first compressor 43 is driven as the main power source, the outside air temperature drops and the main power source / auxiliary power source can be switched. When it occurs, the auxiliary power source after switching (second compressor 53) and the auxiliary power source after switching (first compressor 43) do not overlap each other so that the drives of both the main power source (second compressor 53) and the auxiliary power source (first compressor 43) after switching do not overlap. The drive of the first compressor 43) was stopped, but during the cooling operation in which only the second compressor 53 was driven as the main power source, the outside air temperature rose and the main power source / auxiliary power source was switched. When ~ T23) ”, the main power source after switching (second compressor 53) and the auxiliary power source after switching (first compressor 43) during the second predetermined time shorter than the first predetermined time. After controlling so that the drives of both are overlapped with each other, the drive of the auxiliary power source (first compressor 43) after switching may be stopped. By doing so, it is possible to suppress fluctuations in the chilled water temperature as compared with the case where the drives of the first compressor 43 and the second compressor 53 are overlapped during the first predetermined time (time t22 to t23). , Stable operation can be realized. However, when setting the second predetermined time, it is desirable to set a time so that the fluctuation of the chilled water temperature with respect to the target chilled water temperature does not become large by conducting an experiment in advance.

Further, in the present embodiment, as shown in FIG. 7, during the heating operation in which only the first compressor 43 is driven as the main power source, the outside air temperature rises and the main power source / auxiliary power source is switched. When it occurs, and as shown in FIG. 9, during the cooling operation in which only the first compressor 43 is driven as the main power source, the outside air temperature drops and switching between the main power source and the auxiliary power source occurs. In that case, the drive of the main power source after switching and the drive of the auxiliary power source after switching were stopped at the same time so that the drives of both the main power source and the auxiliary power source did not overlap. The actual hot water temperature with respect to the target hot water temperature or the actual chilled water temperature with respect to the target chilled water temperature fluctuates greatly by conducting experiments in advance without simultaneously starting the drive of the main power source and stopping the drive of the auxiliary power source after switching. The drive of the main power source may be started after a certain period of time when the auxiliary power source is stopped, so that the drives of both the main power source and the auxiliary power source do not overlap. be.

Further, in the present embodiment, the geothermal heat exchanger 23 is shown as the heat source of the geothermal heat pump unit 4, but as the heat source, water heat sources such as lakes, reservoirs, and wells can be used in addition to the geothermal heat. The type does not matter as long as it uses a heat source other than the outside air, and the heat source side circulating liquid H supplied to the first heat source side heat exchanger 46 is like the heat source side circulation circuit 20. It does not have to be in a form of circulating in a closed circuit, and the heat source side circulating fluid H may be in an open type such that it is discharged to the outside after heat exchange by the first heat source side heat exchanger 46. be.

1 Combined heat source heat pump device 6 Control device 30 Load side circulation circuit 36 Air conditioning terminal 40 1st heat pump circuit 41 1st load side heat exchanger 43 1st compressor 45 1st expansion valve 46 1st heat source side heat exchanger 50 2nd Heat pump circuit 51 2nd load side heat exchanger 52c Outside air temperature sensor 53 2nd compressor 55 2nd expansion valve 57 Air heat exchanger

Claims (3)

A first heat pump circuit including a first compressor, a first load side heat exchanger, a first expansion valve, and a first heat source side heat exchanger capable of exchanging heat with a predetermined heat source separate from the outside air.
A second heat pump circuit equipped with a second compressor, a second load side heat exchanger, a second expansion valve, and a second heat source side heat exchanger capable of exchanging heat with the outside air.
A load side circulation circuit provided with the first load side heat exchanger, the second load side heat exchanger, and a load terminal to circulate hot or cold water.
An outside air temperature detecting means for detecting the outside air temperature,
It has a control device that controls the operation, and
The control device includes the first compressor and the first compressor depending on whether the outside air temperature detected by the outside air temperature detecting means is higher or lower than a predetermined switching temperature during operation when hot water or cold water is supplied to the load terminal. In the combined heat source heat pump device that switches which of the second compressors is used as the main power source and which is used as the auxiliary power source.
During the operation in which only the main power source is driven, the control device determines that the outside air temperature detected by the outside air temperature detecting means changes in the direction in which the load increases and reaches the predetermined switching temperature. Based on this, when the main power source and the auxiliary power source are switched, the driving of the main power source after the switching is started and the driving of the auxiliary power source after the switching is stopped for a first predetermined time. During the period, the drive of both the main power source after switching and the auxiliary power source after switching is controlled to overlap, and then the drive of the auxiliary power source after switching is controlled to be stopped.
During the operation in which only the main power source is driven, the control device determines that the outside air temperature detected by the outside air temperature detecting means changes in the direction in which the load decreases and reaches the predetermined switching temperature. Based on this, when the main power source and the auxiliary power source are switched, the driving of the main power source after the switching is started, and the driving of the auxiliary power source after the switching is stopped. During the second predetermined time shorter than the predetermined time, the drive of the auxiliary power source after switching is stopped after controlling the drive of both the main power source after switching and the auxiliary power source after switching so as to overlap. A combined heat source heat pump device characterized by being controlled so as to be operated. The control device drives the second compressor as the main power when the outside air temperature detected by the outside air temperature detecting means is equal to or higher than the predetermined switching temperature during the heating operation in which hot water is supplied to the load terminal. The source, the first compressor is set as the auxiliary power source, and when the outside air temperature detected by the outside air temperature detecting means is less than the predetermined switching temperature, the first compressor is used as the main power source. The second compressor is set as the auxiliary power source, and the second compressor is set as the auxiliary power source.
During the heating operation in which only the second compressor as the main power source is driven, the control device reaches the predetermined switching temperature by lowering the outside air temperature detected by the outside air temperature detecting means. Based on this, when the main power source and the auxiliary power source are switched, the driving of the first compressor that becomes the main power source is started after the switching, and the first compressor that becomes the auxiliary power source after the switching is started. 2 In stopping the drive of the compressor, both the first compressor, which becomes the main power source after switching, and the second compressor, which becomes the auxiliary power source after switching, are driven during the first predetermined time. After controlling so as to overlap, control is performed so as to stop the drive of the second compressor, which is the auxiliary power source, after switching.
During the heating operation in which only the first compressor as the main power source is driven, the outside air temperature detected by the outside air temperature detecting means of the control device rises and reaches the predetermined switching temperature. Based on this, when the main power source and the auxiliary power source are switched, the driving of the second compressor, which is the main power source, is started after the switching, and the auxiliary power source becomes the auxiliary power source after the switching. In stopping the drive of the first compressor, the second compressor that becomes the main power source after switching and the second compressor that becomes the auxiliary power source after switching during the second predetermined time shorter than the first predetermined time. The present invention is characterized in that, after controlling so that the drives of both of the compressors overlap, the drive of the first compressor, which is the auxiliary power source, is controlled to be stopped after switching. 1. The combined heat source heat pump device according to 1. The control device drives the first compressor as the main power when the outside air temperature detected by the outside air temperature detecting means is equal to or higher than the predetermined switching temperature during the cooling operation in which cold water is supplied to the load terminal. The source, the second compressor is set as the auxiliary power source, and when the outside air temperature detected by the outside air temperature detecting means is less than the predetermined switching temperature, the second compressor is used as the main power source. The first compressor is set as the auxiliary power source, and the first compressor is set as the auxiliary power source.
During the cooling operation in which only the second compressor as the main power source is driven, the outside air temperature detected by the outside air temperature detecting means of the control device rises and reaches the predetermined switching temperature. Based on this, when the main power source and the auxiliary power source are switched, the driving of the first compressor that becomes the main power source is started after the switching, and the first compressor that becomes the auxiliary power source after the switching is started. 2 In stopping the drive of the compressor, both the first compressor, which becomes the main power source after switching, and the second compressor, which becomes the auxiliary power source after switching, are driven during the first predetermined time. After controlling so as to overlap, control is performed so as to stop the drive of the second compressor, which is the auxiliary power source, after switching.
During the cooling operation in which only the first compressor as the main power source is driven, the control device reaches the predetermined switching temperature after the outside air temperature detected by the outside air temperature detecting means is lowered. Based on this, when the main power source and the auxiliary power source are switched, the driving of the second compressor, which is the main power source, is started after the switching, and the auxiliary power source becomes the auxiliary power source after the switching. In stopping the drive of the first compressor, the second compressor that becomes the main power source after switching and the second compressor that becomes the auxiliary power source after switching during the second predetermined time shorter than the first predetermined time. The present invention is characterized in that, after controlling so that the drives of both of the compressors overlap, the drive of the first compressor, which is the auxiliary power source, is controlled to be stopped after switching. 1. The combined heat source heat pump device according to 1.

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