JP6359397B2 - 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 that performs a defrosting operation while driving a heating circulation pump and continuing a heating operation.

  Recently, “geothermal heat” stored in the earth under the heat of the sun has little change in temperature throughout the year, so geothermal heat pumps that can effectively use this geothermal energy are attracting attention. In particular, geothermal heat pumps have the property that they can be stably heated even in cold regions where the winter is cold.

  Conventionally, a ground having a first compressor, a first heating heat exchanger, a first expansion valve, and a ground heat source heat exchanger in order to support the ground heat heat pump and further improve the heating output by the air heat heat pump. A heat heat pump, a second compressor, a second heating heat exchanger, a second expansion valve, and an air heat heat pump having an air heat source heat exchanger, the first heating heat exchanger and the second heating heat as a condenser The exchanger is connected in series to a heating circulation circuit having a heating circulation pump that circulates the circulating fluid to the heat radiating terminal, and a heat source with high heat collection efficiency is selected according to the outside air temperature, and a geothermal heat pump or air heat is selected. Either one of the heat pumps is operated and the heating circulation pump is driven, or both the underground heat pump and the air heat heat pump are operated and heated according to the size of the heating load. By driving the ring pump, the heat radiation terminal side of the heating medium heat pump apparatus which performs by heating (circulating fluid) heating operation is supplied to the heat radiating terminal is devised (for example, Patent Document 1).

JP 2014-35109 A

  By the way, in such a heat pump device in which a geothermal heat pump and an air heat pump are connected in series, when a heating operation is performed when the outside air temperature is low, an air heat source heat exchanger constituting the air heat heat pump is When the air heat source heat exchanger is frosted, the heat exchange efficiency is reduced, so that it is necessary to defrost the air heat source heat exchanger.

  As the defrosting operation, the second expansion valve constituting the air heat heat pump is fully opened, the high-temperature refrigerant compressed by the second compressor is circulated through the second heating heat exchanger, and the second expansion is performed. The frost generated in the air heat source heat exchanger is melted by passing through the second expansion valve without being depressurized by the valve and supplied to the air heat source heat exchanger (defrosting operation).

  When performing this defrosting operation, it is conceivable to continue the operation of the geothermal heat pump and the drive of the heating circulation pump so that the air-conditioned space heated by the heat radiating terminal is not heated. When the defrosting operation is performed while the heating circulation pump is driven at the same rotational speed, the heat of the refrigerant compressed by the second compressor for defrosting the air heat source heat exchanger passes through the second heating heat exchanger. Therefore, there is a problem that the defrosting operation time is prolonged because it is lost to the circulating fluid on the heat radiating terminal side, and the frost generated in the air heat source heat exchanger is less likely to melt as the outside air temperature is lower. It was.

  This invention is made | formed in view of such a background, and makes it a subject to provide the composite heat source heat pump apparatus which can complete a defrosting operation | work quickly, ensuring a heating output suitably. .

In order to solve the above-described problems, the present invention provides a heating circuit having a heating circulation pump for circulating a circulating liquid in a heat radiating terminal, and a first heating as a condenser disposed in the heating circuit. A heat exchanger, a second heating heat exchanger as a condenser disposed in the heating circulation circuit, a ground heat source heat exchanger that heats the first refrigerant that is collected from the ground and circulated in the circuit, and A first compressor that compresses the first refrigerant, the first heating heat exchanger that circulates the first refrigerant discharged from the first compressor, and the outflow from the first heating heat exchanger. A first expansion valve that depressurizes the first refrigerant, a first heat pump circuit that heats the circulating fluid via the first heating heat exchanger, and a second heat that is collected from outside air and circulated in the circuit An air heat source heat exchanger for heating the refrigerant, and a second pressure for compressing the second refrigerant. A second heating heat exchanger for circulating the second refrigerant discharged from the second compressor, and a second expansion valve for reducing the pressure of the second refrigerant flowing out of the second heating heat exchanger And a second heat pump circuit for heating the circulating fluid via the second heating heat exchanger, an outside air temperature detecting means for detecting an outside air temperature, and a control device for controlling the operation. One heating heat exchanger is arranged in series upstream of the second heating heat exchanger in the heating circulation circuit, and operates the first heat pump circuit and the second heat pump circuit and drives the heating circulation pump. A heat source heat pump apparatus that performs a heating operation for heating the circulating fluid, wherein the control device converts the second refrigerant discharged from the second compressor into the second heating heat exchanger and the second heat exchanger. Flow expansion valve The defrosting operation is performed to melt the frost generated in the air heat source heat exchanger by supplying to the air heat source heat exchanger, and the heating circulation pump is driven at a predetermined defrosting rotation speed during the defrosting operation. A defrosting operation control means for controlling the first heat pump circuit when the control device determines that a predetermined defrosting start condition for starting the defrosting operation is established during the heating operation. When the defrosting operation control unit starts the defrosting operation and the defrosting operation control unit executes the defrosting operation during the heating operation, the opening degree of the second expansion valve is: The predetermined opening degree larger than that during the heating operation is expanded, the predetermined defrosting rotation speed of the heating circulation pump is lower than the rotation speed during the heating operation, and the outside temperature detected by the outside temperature detecting means Rotational speed according to The circulating fluid is circulated through the heat radiating terminal, and the defrosting operation is performed while heating by the heat radiating terminal is continued .

  According to a second aspect of the present invention, the defrosting operation control means sets the predetermined defrosting rotation speed lower as the outside air temperature detected by the outside air temperature detecting means is lower.

According to claim 1 of the present invention, when the control device determines that a predetermined defrosting start condition for starting the defrosting operation during the heating operation is satisfied, the operation of the first heat pump circuit is continued and the removal is performed. When the defrosting operation control means starts the defrosting operation and executes the defrosting operation during the heating operation, the opening of the second expansion valve is expanded to a predetermined opening larger than that during the heating operation, and the heating circulation The predetermined defrosting rotation speed of the pump is lower than the rotation speed at the time of heating operation and is set to a rotation speed according to the outside air temperature detected by the outside air temperature detecting means. By performing the defrosting operation in a state where the heating by the air is continued, the defrosting operation considering the difficulty of melting the frost generated in the air heat source heat exchanger at high and low outside air temperatures is quickly performed while suitably ensuring the heating output. Can be completed to Than is.

  According to the second aspect of the present invention, the lower the outside air temperature, the lower the predetermined defrosting rotation speed is set, and the lower the outside air temperature is, the lower the outside air temperature is from the second refrigerant through the second heating heat exchanger during the defrosting operation. The amount of heat absorbed by the circulating fluid is reduced, and while maintaining the heating output by suppressing the temperature drop of the circulating fluid flowing out of the second heating heat exchanger as much as possible, it flows out of the second heating heat exchanger and air heat source heat exchange. The amount of heat release for defrosting the air heat source heat exchanger can be secured by suppressing the temperature drop of the second refrigerant supplied to the cooler, and the defrosting operation can be completed quickly.

The external appearance block diagram which shows the main units of the composite heat source heat pump apparatus which concerns on embodiment of this invention. The block diagram which shows the whole structure of the composite heat source heat pump apparatus which concerns on embodiment of this invention. The circuit diagram which shows the defrost operation which concerns on embodiment of this invention. The figure which shows the relationship between the external temperature at the time of the defrost operation which concerns on embodiment of this invention, and the defrost rotation speed of a heating circulation pump.

The configuration of the composite heat source heat pump apparatus 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 composite 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). 5. The composite heat source heat pump device 1 includes a heating circulation circuit 30 as a load-side circulation circuit that circulates a circulation liquid L (for example, hot water or antifreeze liquid) as a heat medium in the heat radiating terminal 36, and a ground heat as a heat source-side circulation circuit. It has a circulation circuit 20, a control device 6 (61, 62, 63) as control means for controlling the operation of the composite heat source heat pump device 1, and a remote controller 60 that sends a signal to the control device 6.

  As shown in FIG. 2, the composite heat source heat pump apparatus 1 according to the present embodiment uses a ground heat source to heat the circulating liquid L on the heat radiating terminal 36 side, and the first heating heat exchanger 41 of the first heat pump circuit 40. And a combined heat source heat pump device in which a second heating heat exchanger 51 of a second heat pump circuit 50 that heats the circulating fluid L on the heat radiation terminal 36 side using an air heat source is connected in series to the heating circulation circuit 30. In addition, the first heating heat exchanger 41 is disposed on the upstream side of the second heating heat exchanger 51 with respect to the flow of the circulating liquid L circulating in the heating circulation circuit 30. The composite heat source heat pump device 1 can function as a heating device and a cooling device, but in the following embodiments, components and operations when mainly used as a heating device will be described.

  The first heat pump circuit 40 circulates the first variable-capacity compressor 43 that compresses the first refrigerant C1 and the high-temperature first refrigerant C1 discharged from the first compressor 43, and the high-temperature first refrigerant C1. And a first heating heat exchanger 41 as a first condenser that performs heat exchange between the circulating fluid L flowing in the heating circulation circuit 30 and a first refrigerant C1 that flows out of the first heating heat exchanger 41 is depressurized. As a first expansion valve 44 that performs heat exchange between the first expansion valve 44 serving as a decompression unit, the decompressed low-temperature first refrigerant C1 from the first expansion valve 44, and the heat medium H1 that flows through the underground heat circulation circuit 20. The underground heat source heat exchanger 45 and a first refrigerant pipe 42 that connects these in an annular shape are configured. The first heat pump circuit 40 circulates the first refrigerant C1 and heats the circulating liquid L flowing through the heating circulation circuit 30 via the first heating heat exchanger 41.

  In the underground 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. 1st refrigerant | coolant temperature sensor provided in the 1st refrigerant | coolant piping 42 from the 1 expansion valve 44 to the underground heat source heat exchanger 45, ie, the 1st refrigerant | coolant piping 42 of a low voltage | pressure side, and detects the temperature of the 1st refrigerant | coolant C1 of a low voltage | pressure side. It is.

  The second heat pump circuit 50 circulates the variable-capacity second compressor 53 that compresses the second refrigerant C2 and the high-temperature second refrigerant C2 discharged from the second compressor 53, and this high-temperature second refrigerant C2 And the second heating heat exchanger 51 as a second condenser for exchanging heat with the circulating liquid L flowing through the heating circulation circuit 30, and the second refrigerant C2 flowing out from the second heating heat exchanger 51 is depressurized. The heat of the second expansion valve 54 serving as a decompression means and the low-temperature second refrigerant C2 decompressed from the second expansion valve 54 circulates and the air sent by the operation of the low-temperature second refrigerant C2 and the blower fan 56. An air heat source heat exchanger 55 serving as a second evaporator that performs exchange and a second refrigerant pipe 52 that connects these in an annular shape are configured. The second heat pump circuit 50 circulates the second refrigerant C2 and heats the circulating liquid L flowing through the heating circulation circuit 30 via the second heating heat exchanger 51. The second refrigerant pipe 52 is provided with a four-way valve 58 as a switching valve for switching between heating and cooling by switching the flow direction of the second refrigerant C2 in the second heat pump circuit 50.

  In the air heat 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. A second refrigerant temperature sensor is provided in the second refrigerant pipe 52 from the expansion valve 54 to the air heat source heat exchanger 55 and detects the temperature of the second refrigerant C2 flowing out from the second expansion valve 54. A second refrigerant evaporation temperature sensor that is provided in the second refrigerant pipe 52 from the air heat source heat exchanger 55 to the second compressor 53 and detects the temperature of the second refrigerant C2 flowing out of the air heat source heat exchanger 55; Reference numeral 57 denotes an outside air temperature sensor as outside air temperature detecting means for detecting the outside air temperature.

  In addition, as a refrigerant | coolant of the 1st heat pump circuit 40 and the 2nd heat pump circuit 50, arbitrary refrigerant | coolants, such as HFC refrigerant | coolants, such as R410A and R32, and a carbon dioxide refrigerant | coolant, can be used.

  The 1st heating heat exchanger 41, the underground heat source heat exchanger 45, and the 2nd heating heat exchanger 51 are comprised by the plate type heat exchanger, for example. In this plate heat exchanger, a plurality of heat transfer plates are stacked, and a refrigerant flow path for circulating a refrigerant and a fluid flow path for circulating a fluid as a heat medium are alternately formed with each heat transfer plate as a boundary. ing.

  The underground heat circulation circuit 20 includes an underground heat source heat exchanger 45, an underground heat exchanger 23 installed in the ground as a heat source for heating the first refrigerant C1 flowing through the underground heat source heat exchanger 45, It is provided with the underground heat piping 21 which connects these cyclically | annularly. In addition, the underground heat pipe 21 has a variable rotation speed (the number of rotations per unit time) for circulating an antifreeze liquid in which ethylene glycol, propylene glycol or the like is added as a heat medium H1 to the underground heat circulation circuit 20. A pump 22 is provided. In addition, the code | symbol 24 in FIG. 2 is the underground system turn which adjusts the pressure of the underground heat circulation circuit 20 by storing the heat medium H1.

  Here, in the underground heat circulation circuit 20, when performing the heating operation, the underground heat exchanger 23 collects the underground heat from the ground, and the heat transfer medium is heated by the underground heat circulation pump 22. It is supplied to the underground heat source heat exchanger 45. Then, in the underground heat source heat exchanger 45, the first refrigerant C1 flowing through the refrigerant flow path of the underground heat source heat exchanger 45 and the heat medium flowing through the fluid flow path of the underground heat source heat exchanger 45 face each other. The ground heat collected by the underground heat exchanger 23 is pumped to the first refrigerant C1 side to heat the first refrigerant C1, and the underground heat source heat exchanger 45 is exchanged. Will function as an evaporator.

  The heating circuit 30 includes a first heating heat exchanger 41 as a first condenser, a second heating heat exchanger 51 as a second condenser, a floor heating panel and a panel convector for heating the air-conditioned space, etc. The heat radiating terminal 36 as a load terminal and a heating pipe 31 that connects these in a circular shape in order from the upstream side are provided. The heating pipe 31 is provided with a heating circulation pump 32 that circulates the circulating liquid L in the heating circulation circuit 30. Each of the heating pipes 31 branched for each heat radiation terminal 36 is opened and closed to open the heat radiation terminal 36. Thermally operated valves 33 are provided for controlling the supply of the circulating fluid L to each. In addition, although the two heat radiating terminals 36 are provided in FIG. 2, one may be sufficient and three or more may be sufficient, and quantity and a specification are not specifically limited.

  Thus, in the heating circulation circuit 30, the first heating heat exchanger 41 as the first condenser and the second heating heat exchanger 51 as the second condenser are connected in series, and the heating circulation circuit 30 is The circulating liquid L to be circulated is configured to be supplied to the heat radiating terminal 36 through the second heating heat exchanger 51 after flowing through the first heating heat exchanger 41.

  In the heating circulation circuit 30 shown in FIG. 2, reference numeral 34 denotes a return hot water temperature sensor that detects the temperature of the circulating fluid L that is provided in the heating pipe 31 and flows into the first heating heat exchanger 41 from the heat radiating terminal 36. Reference numeral 35 denotes a heating system that stores the circulating fluid L and adjusts the pressure of the heating circulation circuit 30.

  The control device 6 includes a geothermal heat pump control device 61 that controls the operation of the underground heat circulation circuit 20, the first heat pump circuit 40, and the heating circulation circuit 30, and an air heat heat pump that controls the operation of the second heat pump circuit 50. A control device 62 and a defrosting operation control device 63 as defrosting operation control means for controlling the defrosting operation are provided. The control device 6 includes a storage unit that stores various data and programs, and a control unit that performs calculation / control processing. Each temperature sensor such as the outside air temperature sensor 57 and the temperature sensors 42a and 42b, and the remote controller 60 are provided. The operation of the composite heat source heat pump device 1 can be controlled in response to the signal from.

  During the heating operation, the control device 6 sets the detection value of the return hot water temperature sensor 34 that detects the temperature of the circulating fluid L immediately upstream of the first heating heat exchanger 41 based on the set temperature of the remote controller 60. In the heating operation by the operation of the first heat pump circuit 40, the rotation speed of the first compressor 43 is controlled so as to reach the target hot water temperature, and in the heating operation by the operation of the second heat pump circuit 50, the second compressor 53 is controlled. The rotational speed is controlled, and when both the first heat pump circuit 40 and the second heat pump circuit 50 are operating, the rotational speeds of the first compressor 43 and the second compressor 53 are controlled. That is, the control device 6 is installed in the heating circulation circuit 30 immediately upstream of the first heating heat exchanger 41, and the detection value of one return hot water temperature sensor 34 that detects the temperature of the circulating fluid L that has flowed out from the heat radiation terminal 36. To determine the overall heating load, and control the operation of either the first heat pump circuit 40 or the second heat pump circuit 50, or both the first heat pump circuit 40 and the second heat pump circuit 50 according to this. It is configured as follows.

  The defrosting operation control device 63 drives the heating circulation pump 32 at a predetermined defrosting rotation speed and continues the heating operation by the heat radiating terminal 36, so that the high-temperature second refrigerant C2 discharged from the second compressor 53 is continued. Is supplied to the air heat source heat exchanger 55 to perform a defrosting operation for melting frost generated in the air heat source heat exchanger 55.

  As shown in FIG. 3, the defrosting operation is to circulate the second refrigerant C2 in the same direction as in the heating operation (see the air heat pump unit 5 in FIG. 2). In the frost operation, the opening degree of the second expansion valve 54 is expanded to a predetermined opening degree that is larger than that in the heating operation before the defrosting operation. The second refrigerant C2 is supplied to the second heating heat exchanger 51 to exchange heat with the circulating fluid L, and the second refrigerant C2 flowing out of the second heating heat exchanger 55 is decompressed by the second expansion valve 54. Without passing through the second expansion valve 54, the second refrigerant C2 is supplied to the air heat source heat exchanger 55 while being warm, and melts frost generated in the air heat source heat exchanger 55. The 2nd refrigerant | coolant C2 which distribute | circulated the heat exchanger 55 returns to the 2nd compressor 53.

  The start of the defrosting operation is, for example, whether or not the outside air temperature detected by the outside air temperature sensor 57 has reached a preset defrosting starting temperature, or the outside air temperature detected by the outside air temperature sensor 57 and the second refrigerant temperature. The control device 6 determines whether or not a predetermined defrosting start condition is satisfied, such as whether or not the temperature difference from the temperature of the second refrigerant C2 detected by the sensor 52b has reached a preset temperature difference. If it is determined that the defrosting start condition is satisfied, the defrosting operation can be started. The completion of the defrosting operation is whether or not the temperature of the second refrigerant C2 that has passed through the air heat source heat exchanger 55 detected by the second refrigerant evaporation temperature sensor 52c has reached a preset defrosting end temperature. For example, the control device 6 determines whether or not a predetermined defrosting end condition is satisfied, and when it is determined that the defrosting end condition is satisfied, the defrosting operation can be ended.

  The defrosting operation control device 63 drives the rotation speed of the heating circulation pump 32 at a predetermined defrosting rotation speed when the defrosting operation of the air heat source heat exchanger 55 is executed. The predetermined defrosting rotational speed of 32 is set lower than the rotational speed during heating operation. For example, when the rotation speed of the heating circulation pump 32 in the heating operation is 3500 rpm, the predetermined defrosting rotation speed of the heating circulation pump 32 can be set to a lower rotation speed, and the predetermined defrosting of the heating circulation pump 32 is performed. As shown in FIG. 4, the rotation speed is lower than the rotation speed (3500 rpm) during the heating operation, and is set according to the outside air temperature during the defrosting operation. Describing in detail with reference to FIG. 4, when the outside air temperature x is higher than 5 ° C. during the defrosting operation, the predetermined defrosting rotation speed of the heating circulation pump 32 is 2000 rpm, the outside air temperature x is 0 ° C. or more, and 5 When the temperature is equal to or lower than 0 ° C., the predetermined defrosting rotation speed of the heating circulation pump 32 is set to 1500 rpm, and when the outside air temperature x is lower than 0 ° C., the predetermined defrosting rotation speed of the heating circulation pump 32 is set to 1000 rpm. The lower the is, the lower the rotational speed of the heating circulation pump 32 during the defrosting operation is set. The relationship between the outside air temperature x shown in FIG. 4 and the defrosting rotation speed of the heating circulation pump 32 is stored in advance in the storage unit of the control device 6.

Next, the operation of the composite heat source heat pump apparatus 1 shown in FIGS. 1 and 2 will be described.
When the remote control 60 gives an instruction to heat the air-conditioned space by the heat radiating terminal 36, the control device 6 uses the ground heat source and the first heat pump circuit 40 and the air heat source based on the outside air temperature detected by the outside air temperature sensor 57. Of the second heat pump circuits 50 using the above, the one having the better heat collection 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 more) as in spring or autumn, and the heating load is small, the control device 6 operates only the second heat pump circuit 50 using the air heat source. Let In this case, the control device 6 starts driving the second compressor 53, the second expansion valve 54, the blower fan 56, and the heating circulation pump 32, and the heating operation is started. When the heating operation is started, the second heating heat exchanger 51 exchanges heat between the circulating liquid L circulated by the heating circulation pump 32 and the high-temperature and high-pressure second refrigerant C2 discharged from the second compressor 53, The heated circulating liquid L is supplied to the heat radiating terminal 36 to heat the air-conditioned space. In the air heat source heat exchanger 55, the air sent by the operation of the blower fan 56 and the low-temperature and low-pressure discharged from the second expansion valve 54 are used. The second refrigerant C2 is heat-exchanged, and the second refrigerant C2 is heated and evaporated by air heat. In this case, the circulating liquid L circulating in the heating circuit 30 also passes through the first heating heat exchanger 41. At this time, since the first heat pump circuit 40 is not operated, the first heating heat is not supplied. The exchanger 41 passes without being heated.

  On the other hand, when the outside air temperature is low as in winter (for example, 5 ° C. or less), the control device 6 operates only the first heat pump circuit 40 that uses the underground heat source. In this case, the control device 6 starts driving the first compressor 43, the first expansion valve 44, the underground heat circulation pump 22, and the heating circulation pump 32, and the heating operation is started. When the heating operation is started, the first heating heat exchanger 41 exchanges heat between the circulating liquid L circulated by the heating circulation pump 32 and the high-temperature and high-pressure first refrigerant C1 discharged from the first compressor 43, The heated circulating liquid L is supplied to the heat radiating terminal 36 to heat the air-conditioned space, and in the underground heat source heat exchanger 45, it is circulated by the underground heat circulation pump 22 and underground through the underground heat exchanger 23. The heat medium H1 that has collected heat and the low-temperature and low-pressure first refrigerant C1 discharged from the first expansion valve 44 exchange heat, and the first refrigerant C1 is heated and evaporated by underground heat. In this case, the circulating fluid L circulating in the heating circulation circuit 30 also passes through the second heating heat exchanger 51. At this time, since the second heat pump circuit 50 is not operated, the second heating heat The exchanger 51 passes through without being heated.

  In addition, when the heating operation is started up or when either the first heat pump circuit 40 or the second heat pump circuit 50 is operated to perform the heating operation, the outside air temperature is further lowered, and the heating load is increased. Thus, when a desired heating output cannot be obtained by only one operation, the control device 6 performs the heating operation in which both the first heat pump circuit 40 and the second heat pump circuit 50 are operated. In the case of the heating operation in which both the first heat pump circuit 40 and the second heat pump circuit 50 are operated as an example, the control device 6 includes the first compressor 43, the first expansion valve 44, the underground heat circulation pump 22, the first The 2 compressor 53, the 2nd expansion valve 54, the ventilation fan 56, and the heating circulation pump 32 are driven, and heating operation is performed. During the heating operation, in the first heating heat exchanger 41, the circulating fluid L circulated by the heating circulation pump 32 and the high-temperature and high-pressure first refrigerant C1 discharged from the first compressor 43 flow oppositely to generate heat. Exchange is performed and the circulating liquid L is heated, and in the second heating heat exchanger 51, the circulating liquid L circulated by the heating circulation pump 32 and the high-temperature and high-pressure second refrigerant discharged from the second compressor 53. C2 flows oppositely, heat exchange is performed, and the circulating liquid L is heated. As described above, the circulating liquid L circulating in the heating circuit 30 is heated by the first heating heat exchanger 41 and then further heated by the second heating heat exchanger 51 to be supplied to the heat radiating terminal 36. When the circulation liquid 36 is circulated, the heat of the circulating liquid L is radiated to the air-conditioned space, whereby the air-conditioned space is heated.

  Next, the operation of the composite heat source heat pump device 1 when the defrosting operation of the air heat source heat exchanger 55 is performed during the heating operation will be described. Here, a case where the defrosting operation is started when both the first heat pump circuit 40 and the second heat pump circuit 50 are operated to perform the heating operation will be described.

  Both the first heat pump circuit 40 and the second heat pump circuit 50 are operated, and the heating circulation pump 32 is driven to circulate the circulating liquid L. In the first heating heat exchanger 41 and the second heating heat exchanger 51, During the heating operation in which the circulating fluid L is heated and the heated circulating fluid L is supplied to the heat radiating terminal 36, the controller 6 detects the outside air temperature detected by the outside air temperature sensor 57 and the second temperature, for example. When it is determined that the refrigerant temperature detected by the refrigerant temperature sensor 52b has reached a predetermined defrosting start condition, the defrosting operation control means 63 starts the defrosting operation and sets the heating circulation pump 32 to a predetermined value set in advance. It is driven at the defrosting rotation speed. At this time, since the first heat pump circuit 40 continues to operate, the defrosting operation is started in a state where the heating operation is continued.

  As described above with reference to FIG. 3, the defrosting operation is to circulate the second refrigerant C2 in the same direction as in the heating operation. The second expansion valve 54 is fully opened, and the second compressor The high temperature second refrigerant C2 discharged from 53 is supplied to the second heating heat exchanger 51 to exchange heat with the circulating liquid L, and the second refrigerant C2 flowing out from the second heating heat exchanger 55 is The second refrigerant C2 passes through the second expansion valve 54 without being depressurized by the second expansion valve 54, and is supplied to the air heat source heat exchanger 55 in a warm state to melt frost generated in the air heat source heat exchanger 55. is there.

  During this defrosting operation, in the second heating heat exchanger 51, heat exchange is performed between the second refrigerant C2 and the circulating liquid L, but the heating circulation pump 32 during the defrosting operation is The motor is driven at a predetermined defrosting rotation speed lower than the rotation speed during the heating operation before the defrosting operation is performed, and the defrosting rotation speed is the rotation during the heating operation as shown in FIG. The rotational speed is set to be lower as the outside air temperature is lower than the speed (for example, 3500 rpm) and according to the outside air temperature during the defrosting operation. From the viewpoint of defrosting, the lower the outside air temperature, the more the frost generated in the air heat source heat exchanger 55 does not melt, and more heat is required for defrosting. By setting the rotation speed of the heating circulation pump 32 low, the amount of heat absorbed from the second refrigerant C2 to the circulating liquid L via the second heating heat exchanger 51 during the defrosting operation is reduced as the outside air temperature is lower. The amount of heat radiation for defrosting the air heat source heat exchanger 55 can be secured, and a defrosting operation taking into account the difficulty of melting frost generated in the air heat source heat exchanger 55 at high and low outside air temperatures is performed. From the viewpoint of heating output, the lower the outside air temperature, the more the heat absorbed from the second refrigerant C2 into the circulating fluid L via the second heating heat exchanger 51 during the defrosting operation. Reduce the amount of And Minimize the temperature drop of the circulating liquid L flowing out of the heat exchanger 51 in which it is possible to secure the heating output.

  And if the control apparatus 6 judges that the temperature of the 2nd refrigerant | coolant C2 which distribute | circulated the air heat source heat exchanger 55 detected with the 2nd refrigerant | coolant evaporation temperature sensor 52c reached | attained predetermined defrost termination conditions, defrosting The operation was terminated, the rotational speed of the heating circulation pump 32 was returned to the rotational speed at the time of the heating operation, and both the first heat pump circuit 40 and the second heat pump circuit 50 that were performed before the defrosting operation were operated. Return to heating operation.

  In the present embodiment, the rotation speed of the heating circulation pump 32 in the normal heating operation is set to 3500 rpm, but is not limited to this, the specifications of the heat pump device, the performance of the compressor, the installation environment, the thermal load, etc. In consideration of the above, it is appropriately set in consideration of the balance between the required heating output and the defrosting operation time.

  Further, in the present embodiment, the defrosting rotation speed of the heating circulation pump 32 during the defrosting operation is determined when the outside circulation temperature x is higher than 5 ° C. as shown in FIG. When the frost rotation speed is 2000 rpm and the outside air temperature x is 0 ° C. or more and 5 ° C. or less, the predetermined defrost rotation speed of the heating circulation pump 32 is 1500 rpm, and when the outside air temperature x is lower than 0 ° C., the heating circulation pump 32. The predetermined defrosting rotation speed is set to 1000 rpm, but is not limited to this, and the pattern of the defrosting rotation speed with respect to the outside air temperature may be set more than three patterns, and the lower the outside air temperature is, The defrosting rotation speed of the heating circulation pump 32 during the defrosting operation only needs to be set low, and by doing so, the lower the outside air temperature, the less the defrosting operation is performed via the second heating heat exchanger 51. First While the amount of heat absorbed from the refrigerant C2 into the circulating liquid L is reduced, the temperature reduction of the circulating liquid L flowing out of the second heating heat exchanger 51 is suppressed as much as possible to ensure the heating output, while the second heating heat exchanger 51, the temperature reduction of the second refrigerant C2 supplied to the air heat source heat exchanger 55 can be suppressed, and a heat radiation amount for defrosting the air heat source heat exchanger 55 can be secured, so that the defrosting operation can be performed quickly. Can be completed.

DESCRIPTION OF SYMBOLS 1 Composite heat source heat pump apparatus 6 Control apparatus 30 Heating circulation circuit 32 Heating circulation pump 36 Heat radiation terminal 40 1st heat pump circuit 41 1st heating heat exchanger 43 1st compressor 44 1st expansion valve 45 Underground heat source heat exchanger 50 1st 2 heat pump circuit 51 second heating heat exchanger 53 second compressor 54 second expansion valve 55 air heat source heat exchanger 57 outside air temperature sensor 61 underground heat pump control device 62 air heat heat pump control device 63 defrosting operation control device C1 First refrigerant C2 Second refrigerant L Circulating fluid

Claims (2)

A heating circulation circuit having a heating circulation pump that circulates the circulating fluid to the heat dissipation terminal;
A first heating heat exchanger as a condenser disposed in the heating circuit;
A second heating heat exchanger as a condenser disposed in the heating circulation circuit;
A ground heat source heat exchanger that heats the first refrigerant that is collected from the ground and circulates in the circuit, a first compressor that compresses the first refrigerant, and the first that is discharged from the first compressor. The first heating heat exchanger for circulating the refrigerant, and a first expansion valve for depressurizing the first refrigerant flowing out of the first heating heat exchanger, and through the first heating heat exchanger A first heat pump circuit for heating the circulating fluid;
An air heat source heat exchanger that heats the second refrigerant that is sampled from outside air and circulates in the circuit, a second compressor that compresses the second refrigerant, and the second refrigerant discharged from the second compressor The second heating heat exchanger to be circulated; and a second expansion valve that depressurizes the second refrigerant flowing out of the second heating heat exchanger, and the circulating fluid passes through the second heating heat exchanger. A second heat pump circuit for heating
Outside temperature detecting means for detecting outside temperature;
A control device for controlling the operation,
The first heating heat exchanger is disposed in series on the upstream side of the second heating heat exchanger in the heating circuit,
A combined heat source heat pump device for operating the first heat pump circuit and the second heat pump circuit and driving the heating circulation pump to heat the circulating fluid;
The controller is
The second refrigerant discharged from the second compressor is supplied to the air heat source heat exchanger through the second heating heat exchanger and the second expansion valve, and is generated in the air heat source heat exchanger. A defrosting operation control means for performing a defrosting operation for melting frost and driving the heating circulation pump at a predetermined defrosting rotation speed during the defrosting operation,
When the control device determines that a predetermined defrosting start condition for starting the defrosting operation is established during the heating operation, the operation of the first heat pump circuit is continued, and the defrosting operation control means is Start the defrosting operation,
When the defrosting operation control means executes the defrosting operation during the heating operation,
The opening of the second expansion valve is expanded to a predetermined opening larger than that during the heating operation,
It said predetermined defrost rotational speed of the heating circulation pump, the lower than the rotational speed during the heating operation, and sets the rotational speed corresponding to the outside air temperature detected by the outside air temperature detection means, the circulation in the heat radiating terminal Circulating the liquid and performing the defrosting operation in a state where heating by the heat radiating terminal is continued ,
A combined heat source heat pump device. The defrosting operation control means includes
The lower the outside air temperature detected by the outside air temperature detecting means, the lower the predetermined defrosting rotation speed,
The composite heat source heat pump device according to claim 1.

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