JP6968769B2 - Combined heat source heat pump device - Google Patents

Description

The present invention relates to a composite heat source heat pump device, and more particularly to a composite heat source heat pump device using air heat and geothermal heat as heat sources.

Conventionally, in this type of combined heat source heat pump device, a first heat pump circuit that uses an underground heat source and a second heat pump circuit that uses an air heat source are provided, and both the first heat pump circuit and the second heat pump circuit operate. In this case, when the target discharge temperature of the refrigerant discharged from the first compressor is T1 and the target discharge temperature of the refrigerant discharged from the second compressor is T2, T1 <T2 is set. When only one of the first heat pump circuit and the second heat pump circuit operates, the target discharge temperature of the refrigerant discharged from the driven side of the first compressor and the second compressor is set to T3. At that time, there was a case where the heating output was improved and a desired heating output was obtained by setting T3 = T1 and heating the circulating liquid flowing through the circulation circuit. (See, for example, Patent Document 1.)

Japanese Unexamined Patent Publication No. 2015-129616

By the way, in this conventional one, although a desired heating output can be obtained, when only one of the first heat pump circuit and the second heat pump circuit is operated, the operation efficiency is poor and the energy saving is achieved. , Further improvement in efficiency was desired.

In order to solve the above problems, in claim 1, the present invention sets the first load side heat exchanger as a condenser, the second load side heat exchanger as a condenser, and the air conditioning terminal in order from the upstream side to the load side. As a load-side circulation circuit that is formed by connecting in a ring shape with pipes and circulates circulating liquid, a first compressor, the first load-side heat exchanger, a first decompression means, and an evaporator that utilizes underground heat. A first heat pump circuit formed by connecting the underground heat source heat exchangers of the above in a ring shape by a first refrigerant pipe, circulating the refrigerant and heating the circulating liquid via the first load side heat exchanger, and a first heat pump circuit. 2 Compressor, 2nd load side heat exchanger, 2nd decompression means, and air heat source heat exchanger as an evaporator using air heat are connected in a ring shape by a 2nd refrigerant pipe, and the refrigerant circulates. When both the second heat pump circuit that heats the circulating fluid via the second load side heat exchanger, the first heat pump circuit, and the second heat pump circuit are operated, the first compressor is used. The control means having a control means for setting T1 <T2 when the target discharge temperature of the discharged refrigerant is T1 and the target discharge temperature of the refrigerant discharged from the second compressor is T2. The means is a target of the refrigerant discharged from the driven side of the first compressor and the second compressor when only one of the first heat pump circuit and the second heat pump circuit is operated. When the discharge temperature is T3, it is set so that T1 <T3 <T2.

Further, in claim 2, the first load side heat exchanger as a condenser, the second load side heat exchanger as a condenser, and the air conditioning terminal are formed by connecting them in a ring shape from the upstream side in order from the upstream side by a load side pipe. , A load-side circulation circuit in which the circulating liquid circulates, a first compressor, the first load-side heat exchanger, a first decompression means, and an underground heat source heat exchanger as an evaporator that utilizes underground heat. A first heat pump circuit that is formed by connecting in a ring shape with one refrigerant pipe and that circulates the refrigerant and heats the circulating liquid via the first load side heat exchanger, a second compressor, and the second load side. A heat exchanger, a second decompression means, and an air heat source heat exchanger as an evaporator that utilizes air heat are connected in a ring shape by a second refrigerant pipe, and the refrigerant circulates and the second load side heat exchange is performed. A first table showing the target discharge temperature after compression of the refrigerant, which is determined according to the target hot water temperature of the circulating liquid circulating in the load side circulation circuit and the second heat pump circuit that heats the circulating liquid via the device. When both the storage unit for storing the data, the second table data, and the third table data and the first heat pump circuit and the second heat pump circuit are operated, the first compressor is used. The target discharge temperature of the discharged refrigerant is set with reference to the first table data, and the target discharge temperature of the refrigerant discharged from the second compressor is set with reference to the second table data. When only one of the first heat pump circuit and the second heat pump circuit operates, the target discharge temperature of the refrigerant discharged from the driven side of the first compressor and the second compressor. The third table has a control unit for setting the heat with reference to the third table data, and the target discharge temperature of the second table data is higher than the target discharge temperature of the first table data. The target discharge temperature of the data is assumed to be higher than the target discharge temperature of the first table data and lower than the target discharge temperature of the second table data.

According to the present invention, when both the first heat pump circuit and the second heat pump circuit are operated, the target discharge temperature of the refrigerant discharged from the second compressor of the second heat pump circuit is the first heat pump circuit. 1 By setting the temperature higher than the target discharge temperature of the refrigerant discharged from the compressor, the circulating liquid is sufficiently heated, the heating output is increased, and the desired heating output can be obtained. When only one of the heat pump circuit and the second heat pump circuit operates, the target discharge temperature of the refrigerant discharged from the driven side of the first compressor and the second compressor is set to have good operating efficiency. The optimum temperature can be determined, a desired heating output can be obtained, and the operating efficiency is improved.

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 flowchart which shows the content of the setting process of the target discharge temperature of the refrigerant discharged from the 1st compressor and the target discharge temperature of the refrigerant discharged from the 2nd compressor at the time of a heating operation. The figure which shows an example of the 3rd table data. The figure which shows an example of the 1st table data. The figure which shows an example of the 2nd table data.

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 FIGS. 1 and 2 as appropriate.
As shown in FIG. 1, the combined heat source heat pump device 1 includes a geothermal 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 control 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 device 51 is connected in series with the load side circulation circuit 30, and the first load side heat exchanger 41 is second with respect to the flow of the load side circulating liquid L circulating in the load side circulation circuit 30. It is arranged on the upstream side of the load side heat exchanger 51. The combined heat source heat pump device 1 can function as a heating device and a cooling device, but in this embodiment, components and operations when the compound heat source heat pump device 1 is mainly used as a heating device will be described.

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 ground. It is configured to include a first heat source side heat exchanger 46 as a medium heat source heat exchanger, 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 in which a flow path for returning to the compressor 43 is formed (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 a second heat source side heat exchanger 57 as an air heat source 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 second heat source side heat exchanger 57 to form a flow path for returning to the second compressor 53 (heating operation). (Time state) and the second refrigerant C2 discharged from the second compressor 53 are circulated in the order of the second heat source side heat exchanger 57, the second expansion valve 55, and the second load side heat exchanger 51. 2 It is possible to switch to a state of forming a flow path for returning to the compressor 53 (during cooling operation or defrosting operation).

Further, in the air source 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. The temperature of the second refrigerant C2 provided on the second refrigerant pipe 52 from the expansion valve 55 to the second heat source side heat exchanger 57 and on the low pressure side (during heating operation) or high pressure side (during defrosting operation or cooling operation). The 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 underground 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 pipe 21, stores the heat source side circulation liquid H, and applies 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 arithmetic and control processing. The control device 6 receives signals from a temperature sensor such as an outside air temperature sensor 52c and a remote controller 60, and receives signals from the remote controller 60. The operation of the combined heat source heat pump device 1 can be controlled.

In the control device 6, the detection value of the return temperature sensor 34 that detects the temperature of the load-side circulating fluid L on the immediately upstream side of the first load-side heat exchanger 41 during the heating operation is set based on the set value of the remote control 60. The rotation speed of the first compressor 43 of the first heat pump circuit 40 and the rotation speed of the second compressor 53 of the second heat pump circuit 50 are controlled so as to reach the target hot water temperature. That is, the control device 6 grasps the entire heating load from the temperature of the load-side circulating fluid L flowing out from the air conditioning terminal 36, and controls the operation of the first heat pump circuit 40 and the second heat pump circuit 50 accordingly. It is configured as follows.

Further, the control device 6 controls the target discharge temperature of the refrigerant discharged from the first compressor 43 based on the detection value of the return temperature sensor 34, the rotation speed of the first compressor 43, and the set value of the remote controller 60. Determine and set based on. Then, during the heating operation, the control device 6 of the first expansion valve 45 so that the temperature of the refrigerant discharged from the first compressor 43 detected by the refrigerant discharge temperature sensor 42a becomes the set target discharge temperature. The opening and closing control is performed. Further, the control device 6 controls the target discharge temperature of the refrigerant discharged from the second compressor 53 based on the detection value of the return temperature sensor 34, the rotation speed of the second compressor 53, and the set value of the remote controller 60. Determine and set based on. Then, during the heating operation, the control device 6 of the second expansion valve 55 so that the temperature of the refrigerant discharged from the second compressor 53 detected by the refrigerant discharge temperature sensor 52a becomes the set target discharge temperature. The opening and closing control is performed.

Next, the operation of the combined heat source heat pump device 1 shown in FIGS. 1 and 2 will be described. The arrows in FIG. 2 indicate the flow direction of the refrigerant and the circulating fluid.

A remote control 60 is installed in each of the air-conditioned spaces heated by the air-conditioned terminal 36, and when the remote control 60 gives an instruction to heat the air-conditioned space, the control device 6 controls the outside air temperature detected by the outside air temperature sensor 52c. Based on the above, from the first heat pump circuit 40 using the underground heat source and the second heat pump circuit 50 using the air heat source, the one having the better heat sampling efficiency is selected and operated as the heat source.

For example, when the outside air temperature is not so low (for example, 5 ° C. or higher) as in spring or autumn and the heating load is small, the control device 6 operates only the second heat pump circuit 50 using an air heat source. In this case, the control device 6 starts driving the second compressor 53, the second expansion valve 55, the blower fan 56, and the load-side circulation pump 32, and the heating operation is started. When the heating operation is started, in the second load side heat exchanger 51, the load side circulating liquid L circulated by the load side circulation pump 32 and the high temperature and high pressure second refrigerant C2 discharged from the second compressor 53 are separated. The heat-exchanged and heated load-side circulating fluid L is supplied to the air-conditioning terminal 36 to heat the air-conditioned space, and in the second heat source-side heat exchanger 57, the air sent by the operation of the blower fan 56 and the second expansion The low-temperature low-pressure refrigerant discharged from the valve 55 is heat-exchanged, and the refrigerant is heated and evaporated by air heat. In this case, the load-side circulating fluid L circulating in the load-side circulating circuit 30 also passes through the first load-side heat exchanger 41, but at this time, the first heat pump circuit 40 is not operating. In the first load side heat exchanger 41, the heat exchanger 41 passes through without being heated.

On the other hand, when the outside air temperature is low (for example, 5 ° C. or lower) as in winter, the control device 6 operates only the first heat pump circuit 40 using the underground heat source. In this case, the control device 6 starts driving the first compressor 43, the first expansion valve 45, the heat source side circulation pump 22, and the load side circulation pump 32, and the heating operation is started. When the heating operation is started, in the first load side heat exchanger 41, the load side circulating liquid L circulated by the load side circulation pump 32 and the high temperature and high pressure refrigerant discharged from the first compressor 43 are heat exchanged. The heated load-side circulating fluid L is supplied to the air-conditioning terminal 36 to heat the space to be air-conditioned, and in the first heat source-side heat exchanger 46, it is circulated by the heat-source-side circulating pump 22 and via the underground heat exchanger 23. The heat medium from which the underground heat is collected and the low-temperature low-pressure refrigerant discharged from the first expansion valve 45 are heat-exchanged, and the refrigerant is heated and evaporated by the underground heat. In this case, the load-side circulating fluid L circulating in the load-side circulating circuit 30 also passes through the second load-side heat exchanger 51, but at this time, the second heat pump circuit 50 is not operating. In the second load side heat exchanger 51, the heat exchanger 51 passes through without being heated.

Further, when the desired heating output cannot be obtained only by operating either the first heat pump circuit 40 or the second heat pump circuit 50 when the heating load is large, such as when the heating operation is started, the control device 6 may be used. , Both the first heat pump circuit 40 and the second heat pump circuit 50 are operated. In this case, the control device 6 drives the first compressor 43, the first expansion valve 45, 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. Perform heating operation. During the heating operation, in the first load side heat exchanger 41, the load side circulating liquid L circulated by the load side circulation pump 32 and the high temperature and high pressure refrigerant discharged from the first compressor 43 flow in opposition to each other to generate heat. The exchange was performed to heat the load-side circulating fluid L, and in the second load-side heat exchanger 51, the load-side circulating fluid L circulated by the load-side circulation pump 32 and the second compressor 53 were discharged. The high-temperature and high-pressure refrigerant flows in opposition to each other to exchange heat, and the load-side circulating liquid L is heated. In this way, the load-side circulating fluid L that circulates in the load-side circulation circuit 30 is heated by the first load-side heat exchanger 41 and then also by the second load-side heat exchanger 51, and is heated by the thermal valve 33. It is sent to the air-conditioning terminal 36 via the remote control unit 60 and heats the air-conditioned space instructed by the remote control 60.

Next, referring to the flowchart of FIG. 3, the target discharge temperature of the refrigerant discharged from the first compressor 43 of the first heat pump circuit 40 during the heating operation, and the discharge from the second heat pump circuit 50 second compressor 53. The process of setting the target discharge temperature of the refrigerant to be used will be described.

As shown in FIG. 3, during the heating operation, the control device 6 determines whether or not only the first heat pump circuit 40 of the first heat pump circuit 40 and the second heat pump circuit 50 is operating (step S1). ..

When it is determined in step S1 that only the first heat pump circuit 40 is operating (Yes in step S1), the control device 6 refers to the third table data TC shown in FIG. 4 and refers to the first heat pump circuit. The target discharge temperature T3 of the refrigerant discharged from the first compressor 43 of 40 is determined and set (step S2). The target discharge temperature T3 is higher than the target discharge temperature T1 of the refrigerant discharged from the first compressor 43 when both the first heat pump circuit 40 and the second heat pump circuit 50 described later are operated, which will be described later. The value is lower than the target discharge temperature T2 of the refrigerant discharged from the second compressor 53 when both the first heat pump circuit 40 and the second heat pump circuit 50 are operated.

FIG. 4 is a diagram showing an example of the third table data TC. The third table data TC shows the target discharge temperature of the refrigerant discharged from the compressors 43 and 53, which is determined based on the rotation speed of the compressors 43 and 53 and the set temperature set by the remote controller 60. This third table data TC is referred to for the first heat pump circuit 40 when the first heat pump circuit 40 operates independently, or as described later, the second heat pump circuit when the second heat pump circuit 50 operates independently. See about 50. The third table data TC is stored in a storage unit built in the control device 6. Then, after step S2, the control device 6 returns the process to step S1.

On the other hand, when it is determined in step S1 that only the first heat pump circuit 40 is not in operation (No in step S1), the control device 6 shifts the process to step S3.

In step S3, the control device 6 determines whether or not only the second heat pump circuit 50 of the first heat pump circuit 40 and the second heat pump circuit 50 is operating.

When it is determined in step S3 that only the second heat pump circuit 50 is operating (Yes in step S3), the control device 6 refers to the third table data TC shown in FIG. 4 and refers to the second heat pump circuit. The target discharge temperature T3 of the refrigerant discharged from the second compressor 53 of 50 is determined and set. (Step S2). Then, after step S2, the control device 6 returns the process to step S1.

On the other hand, when it is determined in step S3 that only the second heat pump circuit 50 is not in operation (No in step S3), the control device 6 shifts the process to step S4.

In step S4, the control device 6 determines whether or not both the first heat pump circuit 40 and the second heat pump circuit 50 are operating.

When it is determined in step S4 that both the first heat pump circuit 40 and the second heat pump circuit 50 are operating (Yes in step S4), the control device 6 refers to the first table data TA shown in FIG. Then, the target discharge temperature T1 of the refrigerant discharged from the first compressor 43 of the first heat pump circuit 40 is determined and set, and the second heat pump circuit is referred to with reference to the second table data TB shown in FIG. The target discharge temperature T2 of the refrigerant discharged from the second compressor 53 of 50 is determined and set (step S5).

FIG. 5 is a diagram showing an example of the first table data TA. The first table data TA shows the target discharge temperature of the refrigerant discharged from the first compressor 43, which is determined based on the rotation speed of the first compressor 43 and the set temperature set by the remote controller 60. This first table data TA is referred to for the first heat pump circuit 40 when both the first heat pump circuit 40 and the second heat pump circuit 50 are operating. The first table data TA is stored in a storage unit built in the control device 6.

FIG. 6 is a diagram showing an example of the second table data TB. The second table data TB shows the target discharge temperature of the refrigerant discharged from the second compressor 53, which is determined based on the rotation speed of the second compressor 53 and the set temperature set by the remote controller 60. This second table data TB is referred to for the second heat pump circuit 50 when both the first heat pump circuit 40 and the second heat pump circuit 50 are operating. The second table data TB is stored in a storage unit built in the control device 6.

As can be seen by comparing FIGS. 5 and 6, the value of the target discharge temperature shown in FIG. 6 is higher than the value of the target discharge temperature shown in FIG. Therefore, when both the first heat pump circuit 40 and the second heat pump circuit 50 are operating to perform the heating operation, the target discharge temperature T2 of the refrigerant discharged from the second compressor 53 is the first compression. It is set so as to be higher than the target discharge temperature T1 of the refrigerant discharged from the machine 43. Then, after step S5 or when it is determined as No in step S4, the control device 6 returns the process to step S1.

As described above, in the combined heat source heat pump device 1 according to the present embodiment, the first load side heat exchanger 41, the second load side heat exchanger 51, and the air conditioning terminal 36 are annularly formed by the load side pipe 31 in order from the upstream side. A first load side circulation circuit 30 which is formed by connecting to and circulates the load side circulation liquid L, and a first compressor 43, which heats the load side circulation liquid L via a first load side heat exchanger 41. The heat pump circuit 40, the second heat pump circuit 50 provided with the second compressor 53 and heating the load side circulating fluid L via the second load side heat exchanger 51, and the first heat pump circuit 40 and the second heat pump circuit 50. When both are operated, T1 <T2 when the target discharge temperature of the refrigerant discharged from the first compressor 43 is T1 and the target discharge temperature of the refrigerant discharged from the second compressor 53 is T2. It has a control device 6 to be set to.

Therefore, according to the present embodiment as described above, when both the first heat pump circuit 40 and the second heat pump circuit 50 are operated, the target of the refrigerant discharged from the second compressor 53 of the second heat pump circuit 50 is targeted. The discharge temperature T2 is set higher than the target discharge temperature T1 of the refrigerant discharged from the first compressor 43 of the first heat pump circuit 40. As a result, the temperature of the refrigerant flowing through the second load side heat exchanger 51 becomes high, and it is sufficient to further raise the already high temperature of the load side circulating fluid L flowing into the second load side heat exchanger 51. The heating is performed via the second load side heat exchanger 51, the heating output is increased, and a desired heating output can be obtained. Further, by raising the target discharge temperature of the refrigerant discharged from the second compressor 53, the difference between the temperature of the refrigerant in the second heat source side heat exchanger 57 and the temperature of the refrigerant sucked into the second compressor 53. Therefore, the efficiency of the refrigeration cycle in the second heat pump circuit 50 is improved.

Further, in the present embodiment, the control device 6 is driven among the first compressor 43 and the second compressor 53 when only one of the first heat pump circuit 40 and the second heat pump circuit 50 is operated. When the target discharge temperature of the refrigerant discharged from the fuel pump is T3, T1 <T3 <T2 is set.

Here, conventionally, when only one of the first heat pump circuit 40 and the second heat pump circuit 50 operates, the refrigerant discharged from the driven one of the first compressor 43 and the second compressor 53. When the target discharge temperature of T3 was set to T3, T3 = T1 was set, and an experiment was conducted for the purpose of improving efficiency. When the target discharge temperature T3 was set to T1 <T3 <T2, the operating efficiency was several percent. Was obtained as a result of improvement. From this, when only one of the first heat pump circuit 40 and the second heat pump circuit 50 operates, the refrigerant discharged from the driven one of the first compressor 43 and the second compressor 53 By setting the target discharge temperature T3 of T1 to T1 <T3 <T2, it is possible to determine the optimum temperature with good operation efficiency during independent operation, and it is possible to obtain the desired heating output and operate. It improves efficiency.

It should be noted that the present invention is not limited to the one embodiment described above, and the configurations described in the present embodiment are appropriately combined or selected, and the configurations are appropriately modified without departing from the spirit of the present invention. It is something that can be done. In addition, a part of the configuration of the embodiment can be added, deleted, or replaced.

For example, in the present embodiment, the control device 6 refers to the first table data TA, the second table data TB, and the third table data TC shown in FIGS. 4 to 6, and the refrigerant discharged from the compressors 43 and 53. However, the present invention is not limited to this, although the target discharge temperature of the above is determined and set. For example, the control device 6 prepares one table data to be referred to when setting the target discharge temperature, and both the first heat pump circuit 40 and the second heat pump circuit 50 operate as a heating operation situation. Depending on whether only one of the first heat pump circuit 40 and the second heat pump circuit 50 is operating, a predetermined value according to the operating condition is added to or subtracted from the value of the table data. You may refer to it.

Further, in the present embodiment, only one geothermal heat exchanger 23 is installed in the ground, but a plurality of geothermal heat exchangers 23 may be installed in the ground, and the plurality of geothermal heat exchangers 23 may be installed in the ground. The exchangers 23 may be connected in parallel with each other or in series.

Further, in the present embodiment, the geothermal heat exchanger 23 is installed in the ground, and the geothermal heat exchanger 23 is directly buried in the ground to collect the geothermal heat. 23 is installed in a well, and for example, in the case of heating operation, the one that collects heat from the well water heated by the geothermal heat is also included in the one in which the geothermal heat exchanger 23 is installed in the ground.

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 42 1st refrigerant pipe 43 1st compressor 45 1st expansion valve 46 1st heat source side heat Exchanger (underground heat source heat exchanger)
50 2nd heat pump circuit 51 2nd load side heat exchanger 52 2nd refrigerant pipe 52c Outside air temperature sensor 53 2nd compressor 55 2nd expansion valve 57 2nd heat source side heat exchanger (air heat source heat exchanger)
L Load side circulating fluid

Claims (2)

A load formed by connecting a first load side heat exchanger as a condenser, a second load side heat exchanger as a condenser, and an air conditioning terminal in a ring shape with a load side pipe in order from the upstream side, and a load in which a circulating fluid circulates. Side circulation circuit and
It is formed by connecting a first compressor, the first load side heat exchanger, a first decompression means, and an underground heat source heat exchanger as an evaporator that utilizes underground heat in a ring shape by a first refrigerant pipe. A first heat pump circuit that circulates the refrigerant and heats the circulating liquid via the first load side heat exchanger.
A second compressor, the second load side heat exchanger, a second decompression means, and an air heat source heat exchanger as an evaporator that utilizes air heat are connected in a ring shape by a second refrigerant pipe, and the refrigerant is formed. A second heat pump circuit that circulates and heats the circulating liquid via the second load side heat exchanger.
When both the first heat pump circuit and the second heat pump circuit are operated, the target discharge temperature of the refrigerant discharged from the first compressor is set to T1, and the target discharge temperature of the refrigerant discharged from the second compressor is set to T1. Has a control means for setting T1 <T2 when T2 is set.
The control means is a refrigerant discharged from the driven one of the first compressor and the second compressor when only one of the first heat pump circuit and the second heat pump circuit is operated. A combined heat source heat pump device characterized in that T1 <T3 <T2 is set when the target discharge temperature of is T3. A load formed by connecting a first load side heat exchanger as a condenser, a second load side heat exchanger as a condenser, and an air conditioning terminal in a ring shape with a load side pipe in order from the upstream side, and a load in which a circulating fluid circulates. Side circulation circuit and
It is formed by connecting a first compressor, the first load side heat exchanger, a first decompression means, and an underground heat source heat exchanger as an evaporator that utilizes underground heat in a ring shape by a first refrigerant pipe. A first heat pump circuit that circulates the refrigerant and heats the circulating liquid via the first load side heat exchanger.
A second compressor, the second load side heat exchanger, a second decompression means, and an air heat source heat exchanger as an evaporator that utilizes air heat are connected in a ring shape by a second refrigerant pipe, and the refrigerant is formed. A second heat pump circuit that circulates and heats the circulating liquid via the second load side heat exchanger.
Three tables of first table data, second table data, and third table data showing the target discharge temperature after compression of the refrigerant, which are determined according to the target hot water temperature of the circulating liquid circulating in the load-side circulation circuit. A storage unit that stores data and
When both the first heat pump circuit and the second heat pump circuit are operated, the target discharge temperature of the refrigerant discharged from the first compressor is set with reference to the first table data, and the first is described. 2 When the target discharge temperature of the refrigerant discharged from the compressor is set with reference to the second table data and only one of the first heat pump circuit and the second heat pump circuit operates, the said It has a control unit that sets the target discharge temperature of the refrigerant discharged from the driven side of the first compressor and the second compressor with reference to the third table data.
The target discharge temperature of the second table data is higher than the target discharge temperature of the first table data, and the target discharge temperature of the third table data is higher than the target discharge temperature of the first table data. A composite heat source heat pump device characterized in that the temperature is lower than the target discharge temperature of the second table data.

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