JP2006010137A - Heat pump system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat pump system having a high coefficient of performance of mutually using respective characteristics of a refrigerant circuit becoming a supercritical cycle and an ordinary refrigerating circuit. <P>SOLUTION: This heat pump system 1 has a hot water supply heat pump 2 using a carbon dioxide refrigerant and having a first heat exchanger 7 and a second heat exchanger 9, and an air-conditioning heat pump 3 using a general refrigerant and having a third heat exchanger 25 and a fourth heat exchanger 27. In this system, when performing hot water supply and heating, a coefficient of performance of the hot water supply heat pump 2 is increased by lowering the temperature of hot water supplied to the first heat exchanger 7 by cooling lower layer side hot water of a hot water storage tank 4 by a fifth heat exchanger 41. At the same time, a coefficient of performance of the air-conditioning heat pump 3 is increased by supplying hot water heated by the fifth heat exchanger 41 to the fourth heat exchanger. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a heat pump system that supplies hot water and also performs cooling and heating.

  In recent years, an example of using a natural refrigerant that has little influence on the environment as the refrigerant of the heat pump system is increasing. Among these natural refrigerants, carbon dioxide has not been affected by the ozone layer and is not toxic or flammable.

  However, a heat pump using carbon dioxide as a refrigerant has a supercritical cycle in which the refrigerant is in a supercritical state on the high pressure side of the cycle and does not cause a phase change from the gas phase to the liquid phase. For this reason, the coefficient of performance (COP) is excellent when performing hot water supply that heats low-temperature water to a high temperature. There is a characteristic that the coefficient decreases (see Patent Document 1 below).

  Therefore, conventionally, a heat pump system using a carbon dioxide refrigerant is often used for hot water supply, and is not often used for air conditioning. For this reason, in installation places such as homes and offices, a carbon dioxide refrigerant heat pump system has been installed for hot water supply, and a heat pump type air conditioner using a general refrigerant has been separately installed.

As described above, conventionally, two heat pump systems are arranged side by side, and each of them performs heat dissipation and heat collection, so that the coefficient of performance is not so high when viewed from the whole equipment.
JP 2004-108597 A (Description 0019, FIG. 2)

  The present invention aims to improve a heat pump system, and more specifically, a heat pump system using a refrigerant that is in a supercritical pressure state on the high pressure side of a cycle, such as carbon dioxide refrigerant, and a phase change that occurs on the high pressure side of the cycle in general. The object is to provide a heat pump system having a high coefficient of performance as compared with a system in which these characteristics are mutually utilized by mutually utilizing the characteristics of the heat pump system using the refrigerant.

  In order to achieve the above object, a heat pump system according to the present invention includes a compressor, a first heat exchanger, an expansion valve, and a second heat exchanger, and extends from the compressor to the expansion valve. A hot water supply refrigerant circuit for circulating a supercritical refrigerant on the high-pressure side, a compressor, a third heat exchanger, an expansion valve, and a fourth heat exchanger are interposed, and the expansion is performed from the compressor. And an air conditioning refrigerant circuit that circulates a refrigerant that changes in phase from a gas phase to a liquid phase on the high pressure side leading to the valve. A first warm water forward path for sending warm water heated by the first heat exchanger to an upper layer of the hot water storage tank; a first hot water return path for sending warm water from the lower layer of the hot water storage tank to the first heat exchanger; A second hot water outgoing path for sending hot water having been subjected to heat exchange by the two heat exchangers to the hot water collecting means, a second hot water return path for sending hot water from the hot water collecting means to the second heat exchanger, A third warm water forward path for sending the hot water heat-exchanged by the third heat exchanger to the heat load, a third hot water return path for sending the warm water from the heat load to the third heat exchanger, and the fourth heat exchanger. And a fourth hot water return path for sending warm water from the air conditioning heat collecting means to the fourth heat exchanger.

  Moreover, the 5th hot water which is provided in parallel with the said 1st hot water return path and sends the warm water from the lower layer of the said hot water storage tank to the said 1st heat exchanger via the 5th heat exchanger which heat-exchanges with the said 4th hot water return path. Switching means for switching between circulating a hot water between the circuit and the first warm water outbound path and the first warm water returning path, or circulating the warm water between the first warm water outbound path and the fifth warm water circuit; When the temperature of the lower layer of the hot water storage tank is below a predetermined threshold, hot water is circulated between the first hot water forward path and the first hot water return path, and the temperature of the lower layer of the hot water storage tank exceeds the threshold value. Comprises control means for switching the switching means so as to circulate hot water between the first warm water forward path and the fifth warm water circuit.

  In the heat pump system of the present invention, when the temperature of the lower layer of the hot water storage tank exceeds a predetermined threshold value, the switching means is switched to circulate hot water between the first hot water forward path and the fifth hot water circuit. . Thereby, the warm water sent to the first heat exchanger is cooled by the fifth heat exchanger of the fifth warm water circuit. For this reason, the coefficient of performance of the hot water supply refrigerant circuit can be increased as compared with the case where hot water is simply supplied from the first hot water return path. When the heating operation is performed in the air conditioning refrigerant circuit, the higher the temperature of the hot water in the fourth hot water return path, the better the coefficient of performance. In the present invention, since the temperature of the hot water in the fourth hot water return path is increased by the fifth heat exchanger, the coefficient of performance in the air conditioning refrigerant circuit can also be increased. Thus, in the present invention, the coefficient of performance of the entire system can be increased by taking advantage of the characteristics of the hot water supply refrigerant circuit and the air conditioning refrigerant circuit.

  The heat pump system of the present invention further includes a sixth hot water circuit for sending hot water from an upper layer of the hot water storage tank to a lower layer of the hot water storage tank via a sixth heat exchanger for exchanging heat with the third hot water outgoing path. And when the temperature of the hot water required by the thermal load exceeds a predetermined second threshold, the control means circulates the hot water in the sixth hot water circuit, and the temperature of the hot water required by the thermal load. When the value is less than or equal to the second threshold value, it is preferable that the circulation of the hot water in the sixth hot water circuit is stopped.

  According to this, when the temperature of the hot water required by the thermal load exceeds the second threshold value, that is, when the hot water at the high temperature is required by the thermal load, the control means is the hot water storage tank. Hot hot water is supplied from the upper layer to the sixth hot water circuit. Thereby, since hot water of high temperature can be supplied to the heat load via the sixth heat exchanger and the third hot water outbound route, heating exceeding the capacity of the air conditioning refrigerant circuit alone can be performed.

  In the heat pump system of the present invention, the hot water collecting means has a first ground heat collecting pipe for collecting geothermal heat, and the air conditioning heat collecting means has a second ground heat for collecting geothermal heat. It is preferable to have a heat collection pipe, and the first underground heat collection pipe and the second underground heat collection pipe are arranged close to each other in the ground.

  When the hot water supply operation is performed in the hot water supply refrigerant circuit, low-temperature hot water is supplied to the first geothermal heat collection pipe, and the temperature is raised by collecting geothermal heat from the ground. On the other hand, when the air-conditioning refrigerant circuit is performing a cooling operation, high-temperature hot water is supplied to the second geothermal heat collection pipe, and low-temperature geothermal heat is collected from the ground to lower the temperature. . That is, in the second underground heat collection pipe, exhaust heat generated during cooling is discharged into the ground. In the present invention, since the first geothermal heat collecting pipe and the second geothermal heat collecting pipe are disposed close to each other in the ground, the hot water supply refrigerant circuit is used for the air conditioning. Since the cooling exhaust heat of the refrigerant circuit can be collected and used, the coefficient of performance of the hot water supply refrigerant circuit can be increased. Further, in the air conditioning refrigerant circuit, even if the exhaust heat of the cooling is discharged into the ground, the ground is not overheated because the heat is collected by the first ground heat collecting pipe. Stable cooling capacity can be maintained.

  Next, an example of an embodiment of the heat pump system of the present invention will be described with reference to FIGS. As shown in FIG. 1, the heat pump system 1 of the present embodiment is a dual heat pump system in which a hot water supply heat pump 2 and an air conditioning heat pump 3 are built in one housing C.

  The hot water supply heat pump 2 heats the hot water in the hot water storage tank 4 and includes a hot water supply refrigerant circuit 5. The hot water supply refrigerant circuit 5 includes a compressor 6, a first heat exchanger 7 that is a condenser, an expansion valve 8, and a second heat exchanger 9 that is an evaporator, which are connected in order. Carbon dioxide is used. This carbon dioxide refrigerant is in a supercritical state across the compressor 6, the first heat exchanger 7, and the expansion valve 8 of the hot water supply refrigerant circuit 5.

  The first heat exchanger 7 and the upper layer 4a of the hot water storage tank 4 are connected by the first hot water outgoing path 10, and the lower layer 4b of the hot water storage tank 4 and the first heat exchanger 7 are connected to the first three-way valve 11 and the first heat exchanger 7. It is connected by a first hot water return path 13 provided with one circulation pump 12. The upper layer 4a of the hot water storage tank 4 is provided with a first temperature sensor T1 for detecting the temperature of the internal hot water, and the lower layer 4b of the hot water storage tank 4 is provided with a second temperature sensor T2 for detecting the temperature of the internal hot water. It has been. Further, water is supplied from the lower layer 4b of the hot water storage tank 4, and hot water is supplied from the upper layer 4a.

  The second heat exchanger 9 is connected to the heat collecting means by a second warm water forward path 14 and a second warm water return path 15. In this embodiment, the heat collecting means includes a first underground heat collecting pipe 16, an outdoor fan unit 17 having a heat exchanger and a fan, and a solar heat collector 18. These are connected by a second three-way valve 19 and a third three-way valve 20. A second circulation pump 21 that circulates the warm water is provided in the second warm water return path 15 between the third three-way valve 20 and the second heat exchanger 9. The outdoor fan unit 17 is provided with an outside air temperature sensor To that detects the outside air temperature.

  The air conditioning heat pump 3 supplies heat (hot or cold) to each heat load, and includes an air conditioning refrigerant circuit 22. The air conditioning refrigerant circuit 22 includes a compressor 23, a four-way valve 24 for switching the refrigerant flow during heating and cooling, and a third heat exchange functioning as an evaporator during heating and as a condenser during cooling. The heater 25, the expansion valve 26, and a fourth heat exchanger 27 that is a condenser during heating and an evaporator during cooling are sequentially connected. The refrigerant used in the air conditioning refrigerant circuit 22 is generally used R410A.

  In addition, the third heat exchanger 25 and each heat load are connected by a third hot water forward path 28, and each heat load and the third heat exchanger 25 are connected by a third hot water return path via a third circulation pump 29. 30 is connected. The heat load in the present embodiment includes the indoor radiator 31, the ventilation air conditioning unit 32 installed in the attic space, and the snow-melting heat exchanger 35 that heats the hot water sent to the snow-melting roadbed 34 by the fifth circulation pump 33. It is. A third temperature sensor T <b> 3 that detects the temperature of the hot water supplied to the indoor radiator 31 is provided at the entrance of the indoor radiator 31. The snow melting heat exchanger 35 and the snow melting roadbed 34 are connected by a snow melting circuit 36. The fourth heat exchanger 27 is connected to a second underground heat collecting pipe 39 as a heat collecting means by a fourth warm water forward path 37 and a fourth warm water return path 38. A fourth circulation pump 40 is provided in the fourth hot water return path 38.

  In the present embodiment, a fifth heat exchanger 41 is provided in the fourth hot water return path 38 of the air conditioning refrigerant circuit 22. The fifth heat exchanger 41 heats between the hot water in the fourth hot water return path 38 and the hot water in the fifth hot water circuit 42 that circulates the hot water from the lower layer 4b of the hot water storage tank 4 to the first heat exchanger 7. Exchange. Further, a sixth heat exchanger 43 is provided in the third warm water forward path 28. This sixth heat exchanger 43 is between the hot water in the third hot water outbound path 28 and the hot water in the sixth hot water circuit 45 that circulates the hot water from the upper layer 4a to the lower layer 4b of the hot water storage tank 4 by the sixth circulation pump 44. Perform heat exchange at. Further, the first underground heat collecting pipe 16 and the second underground heat collecting pipe 39 are provided close to the inside of the underground pipe 46 in which sand or water is stored.

  Next, a functional configuration of the heat pump system 1 of the present embodiment will be described with reference to FIG. In the heat pump system 1, as shown in FIG. 2, the hot water supply heat pump 2 and the air conditioning heat pump 3 are controlled by a single controller 47. The hot water supply heat pump 2 is controlled by the compressor 6, the expansion valve 8, the first circulation pump 12, the second circulation pump 21, the sixth circulation pump 44, the first three-way valve 11, the second three-way valve 19, And the third three-way valve 20. The controller 47 receives detection values from the first temperature sensor T1, the second temperature sensor T2, and the outside air temperature sensor To as devices related to the hot water supply heat pump 2, and controls the outdoor fan unit 17.

  In the air conditioning heat pump 3, the controller 47 controls the compressor 23, the expansion valve 26, the four-way valve 24, the third circulation pump 29, and the fourth circulation pump 40. The controller 47 receives a detection value from the third temperature sensor T3 as a device related to the air conditioning heat pump 3, and controls the indoor radiator 31, the ventilation air conditioning unit 32, and the fifth circulation pump 33.

  In addition, the controller 47 stores a value of 40 ° C. as a threshold value of the detection value of the second temperature sensor T2. When the hot water supply operation is performed by the hot water supply heat pump 2 and the heating operation is performed by the air conditioning heat pump 3, the first three-way valve 11 is used when the temperature of the lower layer 4b of the hot water storage tank 4 is 40 ° C. or less which is a threshold value. Thus, the first warm water forward path 10 and the first warm water return path 13 are connected, and the fifth warm water circuit 42 is closed (see FIG. 3). On the other hand, when the temperature of the lower layer 4b of the hot water storage tank 4 exceeds the threshold value of 40 ° C., the first three-way valve 11 connects the first warm water forward path 10 and the fifth warm water circuit 42 to the first warm water return path 13. Is controlled to be in a closed state (see FIG. 4).

  The controller 47 stores a value of 75 ° C. as a threshold value of the detection value of the third temperature sensor T3. When the heating operation is performed by the air conditioning heat pump 3, the temperature of the upper layer 4a of the hot water storage tank 4 exceeds 75 ° C., and the temperature of the hot water required by the indoor radiator 31 is the threshold value. When the temperature exceeds 75 ° C., the sixth circulation pump 44 is operated to send hot water from the upper layer 4a of the hot water storage tank 4 to the sixth heat exchanger 43 via the sixth hot water circuit 45. The exchanger 43 is controlled to heat the hot water sent to the indoor radiator 31 (see FIG. 5). On the other hand, when the temperature of the upper layer 4a of the hot water storage tank 4 is 75 ° C. or lower, or when the temperature of the hot water requested by the indoor radiator 31 is 75 ° C. or lower, which is the threshold value, the controller 47 controls the sixth circulation pump 44. Is controlled to stop the circulation of the hot water in the sixth hot water circuit 45.

  Next, the operation of the heat pump system 1 of the present embodiment will be described with reference to FIGS. 3 to 6. 3 to 6, a circuit indicated by a solid line indicates an active circuit, and a circuit indicated by a dotted line indicates a closed circuit.

  First, with reference to FIG. 3 and FIG. 4, the case where the hot water supply operation is performed by the hot water supply heat pump 2 and the heating operation is performed by the air conditioning heat pump 3 in winter will be described. When a hot water supply operation is performed by the hot water supply heat pump 2, the controller 47 operates the compressor 6 to compress carbon dioxide as a refrigerant and circulate the refrigerant in the hot water supply refrigerant circuit 5. Further, the first circulation pump 12 and the second circulation pump 21 are operated. Here, when the temperature of the lower layer 4b of the hot water storage tank 4 detected by the second temperature sensor T2 is equal to or lower than 40 ° C. which is a threshold value, the first three-way valve 11 causes the first warm water forward path 10 and the first warm water return path 13 to Connect. Further, when the temperature of the hot water required by the third temperature sensor T3 provided in the indoor radiator 31 is 75 ° C. or less, the sixth circulation pump 44 is not operated, Hot water does not flow. Further, when the detected value of the outside air temperature sensor To exceeds 5 ° C., the outdoor fan unit 17 and the solar heat collection are not caused by the second three-way valve 19 and the third three-way valve 20 without passing through the first underground heat collection pipe 16. Heat is collected by the heater 18. Further, in a state where the detected value of the outside air temperature sensor To exceeds 5 ° C., the fifth circulation pump 33 is not operated, and hot water is not circulated in the snow melting circuit 36.

  In the hot water supply refrigerant circuit 5, the refrigerant compressed by the compressor 6 is radiated by the first heat exchanger 7 that is a condenser, depressurized by the expansion valve 8, and then the second heat exchange that is an evaporator. Heat is collected in the vessel 9 and returned to the inlet of the compressor 6. The hot water sent by the first circulation pump 12 is heated by exchanging heat in the first heat exchanger 7 and sent to the upper layer 4 a of the hot water storage tank 4 through the first hot water outgoing path 10. In the present embodiment, the hot water is heated to 90 ° C. by the first heat exchanger 7. Further, the hot water from the lower layer 4 b of the hot water storage tank 4 is returned to the first heat exchanger 7 through the first hot water return path 13. The hot water sent by the second circulation pump 21 is cooled by exchanging heat in the second heat exchanger 9 and sent to the outdoor fan unit 17 and the solar heat collector 18 via the second three-way valve 19. Heat is collected and returned to the second circulation pump 21 via the third three-way valve 20.

  On the other hand, in the air conditioning refrigerant circuit 22, the refrigerant compressed by the compressor 23 passes through the four-way valve 24, dissipates heat in the third heat exchanger 25 that is a condenser, and is decompressed by the expansion valve 26. Thereafter, heat is collected by the fourth heat exchanger 27 that is an evaporator, and returned to the inlet of the compressor 23 through the four-way valve 24. The warm water sent by the third circulation pump 29 passes through the third heat exchanger 25, the sixth heat exchanger 43, the indoor radiator 31, the ventilation air conditioning unit 32, and the snow melting heat exchanger 35. Returned to the third circulation pump 29. At this time, since the hot water in the sixth hot water circuit 45 is not circulated, the sixth heat exchanger 43 does not perform heat exchange. In addition, since the fifth circulation pump 33 is not operated, heat exchange is not performed in the snow melting heat exchanger 35. Further, the hot water sent by the fourth circulation pump 40 passes through the fourth heat exchanger 27, the second underground heat collection pipe 39 and the fifth heat exchanger 41 and is returned to the fourth circulation pump 40. At this time, since the hot water in the fifth hot water circuit 42 is not circulated, heat exchange is not performed in the fifth heat exchanger 41.

  When the operation of the heat pump system 1 is performed in the above state, the temperature of the hot water in the hot water storage tank 4 rises and heating is performed at each heat load. When the temperature of the hot water detected by the second temperature sensor T2, that is, the temperature of the hot water in the lower layer 4b of the hot water storage tank 4 rises and exceeds the threshold value of 40 ° C., the controller 47 sets the first three-way valve 11 Is switched. Specifically, as shown in FIG. 4, the path of the hot water returned to the first circulation pump 12 is switched from the first hot water return path 13 to the fifth hot water circuit 42. Then, the hot water sent by the first circulation pump 12 passes through the fifth hot water circuit 42 through the first heat exchanger 7 and the upper layer 4a to the lower layer 4b of the hot water storage tank 4, and is exchanged by the fifth heat exchanger 41. Is performed, the first three-way valve 11 is returned to the first circulation pump 12.

  In the fifth heat exchanger 41, the temperature of the hot water in the fifth hot water circuit 42 (temperature exceeding 40 ° C.) is higher than the temperature of the hot water in the fourth hot water return path 38 (about 30 ° C.). The warm water in 42 is cooled, and the warm water in the fourth warm water return path 38 is heated. In the hot water supply refrigerant circuit 5 using carbon dioxide refrigerant, the coefficient of performance of the hot water supply refrigerant circuit 5 is better when the difference between the inlet temperature and the outlet temperature of the first heat exchanger 7 is larger. Accordingly, when the hot water supplied to the first heat exchanger 7 is cooled as in the present embodiment, the hot water in the lower layer 4b of the hot water storage tank 4 is used for hot water supply compared to the case where the hot water is sent to the first heat exchanger 7 as it is. The coefficient of performance of the refrigerant circuit 5 is improved. On the other hand, in the refrigerant circuit 22 for air conditioning, the coefficient of performance improves when the temperature of the hot water supplied to the fourth heat exchanger 27 during heating is higher. Therefore, when the hot water sent to the 4th heat exchanger 27 is heated by the 5th heat exchanger 41 like this embodiment, compared with the case where the warm water from the 2nd underground heat collection pipe 39 is sent as it is. The coefficient of performance of the air conditioning refrigerant circuit 22 is improved.

  Next, with reference to FIG. 5, the operation of the heat pump system 1 when a high capacity is required in the heat load for heating will be described. When the indoor radiator 31 requires rapid heating operation or high load operation, the temperature of the hot water supplied to the third hot water outgoing path 28 needs to be increased. In the present embodiment, the case where the temperature exceeds 75 ° C. which is the threshold value of the detection value of the third temperature sensor T3 corresponds to the high load operation. As described above, when an instruction for high load operation is given by an operation panel (not shown) or the like of the indoor radiator 31 and the temperature of the hot water required by the indoor radiator 31 exceeds the threshold of 75 ° C. The controller 47 controls the heat pump system 1 as follows. In the following example, the case where the operation of the snow melting circuit 36 is also performed will be described.

  When the temperature of the hot water required by the indoor radiator 31 exceeds the threshold value of 75 ° C., the controller 47 operates the sixth circulation pump 44 to circulate the hot water in the sixth hot water circuit 45. Since the hot water is supplied to the sixth hot water circuit 45 from the upper layer 4a of the hot water storage tank 4, the hot water circulating in the sixth hot water circuit 45 is at a high temperature. As described above, when high-temperature hot water circulates in the sixth hot water circuit 45, the hot water flowing in the third hot water outgoing path 28 is heated in the sixth heat exchanger 43. In the present embodiment, the temperature of the hot water supplied to the indoor radiator 31 is set to 75 ° C. or higher.

  At this time, the hot water supplied to the indoor radiator 31 is returned to the third circulation pump 29 via the ventilation air conditioning unit 32 and the snow melting heat exchanger 35. At this time, since the fifth circulation pump 33 is operated and the hot water is circulating in the snow melting circuit 36, the hot water in the snow melting circuit 36 is heated by the snow melting heat exchanger 35, and the heated hot water is heated to the snow melting roadbed. 34 is sent to snowmelt.

  As described above, in the present embodiment, even when a high capability is required in the heat load, the required high capability can be handled. Specifically, high-temperature hot water that cannot be obtained by a heat pump using a normal R410A refrigerant can be supplied to each heat load.

  Next, with reference to FIG. 6, the operation when the cooling operation is performed by the air conditioning heat pump 3 and the hot water supply operation is performed by the hot water supply heat pump 2 in the summer will be described. When the air conditioning heat pump 3 is performing a cooling operation, the refrigerant compressed by the compressor 23 in the air conditioning refrigerant circuit 22 is sent to the fourth heat exchanger 27 via the four-way valve 24, and the expansion valve 26. To the third heat exchanger 25, and then returned to the compressor 23 via the four-way valve 24. At this time, the fourth heat exchanger 27 is a condenser, and the third heat exchanger 25 is an evaporator.

  Further, when the cooling operation is performed, since the hot water supplied to the heat load is cooled by the third heat exchanger 25, low-temperature cold water is contained in the third hot water forward path 28 and the third hot water return path 30. It is circulating. On the other hand, in the 4th heat exchanger 27, the warm water sent by the 4th circulation pump 40 is heated, and warm water is sent to the 2nd underground heat collection pipe 39 via the 4th warm water going way 37, and this 2nd In the underground heat collecting pipe 39, the exhaust heat at the time of cooling is discharged into the ground, and the warm water is returned to the fourth circulation pump 40 via the fourth warm water return path 38.

  At this time, in the hot water supply heat pump 2, the hot water supply refrigerant circuit 5 is operated, and the hot water sent by the second circulation pump 21 is cooled by the heat exchange performed by the second heat exchanger 9. It is sent to the first underground heat collecting pipe 16 through the forward path 10 and the second three-way valve 19. Then, geothermal heat is collected in the first geothermal heat collecting pipe 16 to heat the hot water, and the heated hot water is supplied to the second circulation pump via the first hot water return path 13 and the third three-way valve 20. Return to 21.

  Thus, in the present embodiment, when the cooling operation is performed in the air conditioning heat pump 3, and at the same time the hot water supply operation is performed in the hot water supply heat pump 2, the cooling exhaust heat of the air conditioning heat pump 3 generated by the cooling is first. 2 It is discharged into the underground pipe 46 installed underground through the underground heat collecting pipe 39, and at the same time, the heat in the underground pipe 46 is collected by the first underground heat collecting pipe 16. Therefore, since the cooling exhaust heat generated by the air conditioning heat pump 3 can be used for the hot water supply operation in the hot water supply heat pump 2, the coefficient of performance of the entire heat pump system 1 can be increased.

  In the above embodiment, a value of 40 ° C. is used as the threshold value of the detection value of the second temperature sensor T2, but the value is not limited to this and can be determined as appropriate according to the environment in which the heat pump system 1 is installed. Similarly, the temperature of the hot water at the time of high load operation required by the heat load can be set to other values instead of 75 ° C. as in the above embodiment. Further, in the hot water supply refrigerant circuit 5, carbon dioxide is used as a refrigerant. However, the present invention is not limited to this, and other refrigerants may be used as long as the high pressure side of the cycle is in a supercritical state. Further, a refrigerant other than R410A may be used as the refrigerant in the air conditioning refrigerant circuit 22.

The circuit diagram which shows an example of embodiment of the heat pump system of this invention. The block diagram which shows the functional structure of the heat pump system of this embodiment. Explanatory drawing which shows the state which is performing hot water supply operation and heating operation in the heat pump system of FIG. Explanatory drawing which shows the state from which the condition changed from the state of FIG. Explanatory drawing which shows the state which is performing high load heating operation in the heat pump system of FIG. Explanatory drawing which shows the state which is performing hot water supply operation and cooling operation in the heat pump system of FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Heat pump system, 4 ... Hot water storage tank, 5 ... Refrigerant circuit for hot water supply, 6 ... Compressor, 7 ... 1st heat exchanger, 8 ... Expansion valve, 9 ... 2nd heat exchanger, 10 ... 1st hot water outgoing path, DESCRIPTION OF SYMBOLS 11 ... 1st three-way valve (switching means), 13 ... 1st warm water return path, 14 ... 2nd warm water return path, 15 ... 2nd warm water return path, 16, 17, 18 ... Hot water supply heat collecting means, 22 ... Air conditioning refrigerant circuit , Compressors 23 ..., 25 ... third heat exchanger, 26 ... expansion valve, 27 ... fourth heat exchanger, 28 ... third hot water outbound path, 30 ... third hot water return path, 31, 32, 35 ... heat load, 37... 4th warm water outbound path, 38... 4th warm water return path, 39... Air conditioning heat collecting means, 41... 5th heat exchanger, 42.

Claims (3)

A hot water supply refrigerant in which a compressor, a first heat exchanger, an expansion valve, and a second heat exchanger are interposed to circulate a refrigerant that is in a supercritical state on the high pressure side from the compressor to the expansion valve Circuit,
A compressor, a third heat exchanger, an expansion valve, and a fourth heat exchanger are interposed, and a refrigerant that changes phase from a gas phase to a liquid phase is circulated on the high pressure side from the compressor to the expansion valve. A refrigerant circuit for air conditioning
A first hot water forward path for sending hot water heated by the first heat exchanger to an upper layer of the hot water storage tank; a first hot water return path for sending hot water from the lower layer of the hot water storage tank to the first heat exchanger;
A second hot water outgoing path for sending the hot water heat-exchanged by the second heat exchanger to the hot water collecting means, and a second hot water return path for sending the hot water from the hot water collecting means to the second heat exchanger; ,
A third warm water forward path for sending warm water having been subjected to heat exchange in the third heat exchanger to a heat load; a third warm water return path for sending warm water from the heat load to the third heat exchanger;
A fourth warm water forward path for sending the hot water heat-exchanged in the fourth heat exchanger to the air conditioning heat collecting means, and a fourth hot water return path for sending the hot water from the air conditioning heat collecting means to the fourth heat exchanger; ,
A fifth hot water circuit that is provided in parallel with the first hot water return path and sends hot water from a lower layer of the hot water storage tank to the first heat exchanger via a fifth heat exchanger that exchanges heat with the fourth hot water return path; ,
Switching means for switching between circulating the warm water between the first warm water outbound path and the first warm water return path, or circulating the warm water between the first warm water outbound path and the fifth warm water circuit;
When the temperature of the lower layer of the hot water storage tank is equal to or lower than a predetermined threshold, hot water is circulated between the first warm water forward path and the first hot water return path, and when the temperature of the lower layer of the hot water storage tank exceeds the threshold value A heat pump system comprising: control means for switching the switching means so as to circulate hot water between the first hot water outgoing path and the fifth hot water circuit. A sixth hot water circuit for sending the hot water from the upper layer of the hot water storage tank to the lower layer of the hot water storage tank through a sixth heat exchanger for exchanging heat with the third hot water outbound path;
The control means circulates hot water in the sixth hot water circuit when the temperature of the hot water required by the heat load exceeds a predetermined second threshold, and the temperature of the hot water required by the heat load is 2. The heat pump system according to claim 1, wherein when the temperature is equal to or less than a second threshold value, circulation of hot water in the sixth hot water circuit is stopped.   The hot water supply heat collecting means has a first geothermal heat collecting pipe for collecting geothermal heat, the air conditioning heat collecting means has a second geothermal heat collecting pipe for collecting geothermal heat, and the first ground heat collecting pipe. The heat pump system according to claim 1 or 2, wherein the intermediate heat collection pipe and the second underground heat collection pipe are arranged close to each other in the ground.

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