JP6231395B2 - 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 heat pump cycle device in which a ground heat source and an air heat source are connected in parallel is known (for example, Patent Document 1).
For example, when performing a heating operation, the heat pump cycle device described in Patent Document 1 selects either an air heat source or an underground heat source according to the outside air temperature and uses a heat source with high heat collection efficiency. The heating medium (circulating fluid) on the heat dissipation terminal side is heated.

JP 2006-125769 A

  However, in the heat pump cycle device described in Patent Document 1, since either the air heat source or the underground heat source is used as the heat source, the outside air temperature is low and the heating load becomes excessive particularly in a cold region in winter. In some cases, it is assumed that the heating output tends to be insufficient.

  For this reason, in order to add heat to the ground heat heat pump and further improve the heating output by the air heat heat pump, the ground having the first compressor, the first heating heat exchanger, the first expansion valve, and the ground heat source heat exchanger. An intermediate 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 exchanger, Are connected in series, and both a geothermal heat pump and an air heat heat pump are operated, and a heat pump cycle device has been devised in which a heating medium (circulating fluid) on the heat radiating terminal side is heated to perform a heating operation by the heat radiating terminal. (For example, unpublished Japanese Patent Application No. 2012-175620).

  In such a heat pump cycle apparatus in which a geothermal heat pump and an air heat 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 worn. 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, and the refrigerant flow direction of the air heat heat pump is reversed from the refrigerant flow direction during the heating operation. The discharged high-temperature refrigerant is directly supplied to the air heat source heat exchanger to melt the frost generated in the air heat source heat exchanger, and the refrigerant flowing out of the air heat source heat exchanger is decompressed by the second expansion valve. Instead, the second expansion valve is passed, the second heating heat exchanger is circulated, and returned to the second compressor again. (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 heating circulation pump is driven at the same rotational speed, the circulating liquid heated by the first heating heat exchanger of the underground heat pump is circulated through the second heating heat exchanger as the refrigerant of the air heat heat pump. Since the temperature of the circulating fluid that is absorbed into the side and flows out of the second heating heat exchanger and supplied to the heat radiating terminal is lowered, there is a problem that the feeling of heating is impaired if such a state continues for a long time. It was necessary to shorten the time for performing the defrosting operation in order to shorten the time as much as possible.

  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 shortens defrost operation time and does not impair a feeling of heating as much as possible.

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 A switching valve that switches a flow direction of the second refrigerant, and a second heat pump circuit that heats the circulating fluid via the second heating heat exchanger, and a control device that controls the operation. The first heating heat exchanger is disposed in series upstream of the second heating heat exchanger in the heating circulation circuit, operates the first heat pump circuit and the second heat pump circuit, and performs the heating circulation. A combined heat source heat pump device that performs a heating operation in which a pump is driven to heat the circulating fluid, wherein the control device includes the switching valve, and the second refrigerant flows in the heating operation in the flow direction of the second refrigerant. Flow direction It switches so that it may become reverse, supplies the said 2nd refrigerant | coolant discharged from the said 2nd compressor to the said air heat source heat exchanger, and performs the defrost operation which melts the frost which generate | occur | produced in the said air heat source heat exchanger And a defrosting operation control unit that drives the heating circulation pump at a predetermined defrosting rotation speed during the defrosting operation, and the defrosting operation control unit executes the defrosting operation during the heating operation. The opening of the second expansion valve is expanded to a predetermined opening than during the heating operation, and the predetermined defrosting rotation speed of the heating circulation pump is set lower than the rotation speed during the heating operation. The circulating liquid 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 control device drives the first compressor of the first heat pump circuit at a maximum rotational speed during the defrosting operation.

According to the first aspect of the present invention, when the heating circulation pump is driven at a rotation speed lower than the rotation speed during the heating operation during the defrosting operation, the circulating fluid circulates per unit time as compared with the heating operation. Since the flow rate is reduced and the temperature efficiency is increased, the temperature of the circulating fluid L flowing out from the first heating heat exchanger is increased, and the temperature of the circulating fluid flowing into the second heating heat exchanger is increased. In the heat exchanger, the heat absorbed from the circulating fluid side to the second refrigerant side increases, and the temperature of the second refrigerant discharged from the second compressor and supplied to the air heat source heat exchanger also rises. also become more soluble frost occurred exchanger, it is possible to shorten the defrosting operation time, heating is also shall be continued owing to the heat radiation device.

  According to the second aspect, during the defrosting operation, by driving the first compressor of the first heat pump circuit at the maximum rotational speed, the heating output of the second heat pump circuit before the defrosting operation is performed can be obtained. Since the heating output of the first heat pump circuit is increased so as to cover as much as possible, in the first heating heat exchanger, more heat is absorbed from the first refrigerant side to the circulating liquid side, and from the first heating heat exchanger The temperature of the circulating fluid flowing out can be increased, the temperature of the circulating fluid flowing into the second heating heat exchanger becomes high, the temperature of the circulating fluid flowing out of the second heating heat exchanger can also be kept high, and heat dissipation The temperature drop of the circulating fluid supplied to the terminal can be suppressed as much as possible, so that the feeling of heating is not impaired, and the temperature of the circulating fluid flowing out of the first heating heat exchanger can be increased. 2 Heating heat exchanger Since the temperature of the circulating fluid flowing in becomes higher, more heat is absorbed from the circulating fluid side to the second refrigerant side in the second heating heat exchanger and is discharged from the second compressor and supplied to the air heat source heat exchanger. Since the temperature of the second refrigerant is increased, the frost generated in the air heat source heat exchanger is easily melted, and the defrosting operation time can be shortened.

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 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. A first expansion valve 44 serving as a decompression unit, and a first evaporator that performs heat exchange between the decompressed low-temperature first refrigerant C1 from the first expansion valve 44 and the heat medium H1 flowing through the underground heat circulation circuit. 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 the flow direction of the second refrigerant C2 in the second heat pump circuit 50, and the four-way valve 58 is discharged from the second compressor 53. The second refrigerant C2 is circulated in the order of the second heating heat exchanger 51, the second expansion valve 54, and the air heat source heat exchanger 55 to form a flow path that returns to the second compressor 53 (state during heating operation) ) And the second refrigerant C2 discharged from the second compressor 53 are circulated in the order of the air heat source heat exchanger 55, the second expansion valve 54, and the second heating heat exchanger 51, and returned to the second compressor 53. It can be switched to a state where a flow path is formed (a state during a defrosting operation).
In the present embodiment, when the air heat source heat exchanger 55 becomes low temperature and frost is formed, the four-way valve 58 so that the second refrigerant C2 discharged from the second compressor 53 flows toward the air heat source heat exchanger 55. Is switched, and the frost generated in the air heat source heat exchanger 55 is melted by the high-temperature second refrigerant C2 from the second compressor 53.

  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. The 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, that is, the second refrigerant pipe 52 on the low pressure side, and detects the temperature of the second refrigerant C2 on the low pressure side. Reference numeral 57 denotes an outside air temperature sensor 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 medium H <b> 1 with the heat is the underground heat circulation pump 22. Is supplied to the underground heat source heat exchanger 45. In the underground heat source heat exchanger 45, the first refrigerant C1 that flows through the refrigerant flow path of the underground heat source heat exchanger 45 and the heat medium H1 that flows through the fluid flow path of the underground heat source heat exchanger 45 are Heat exchange is performed by flowing in the opposite direction, the underground heat collected by the underground heat exchanger 23 is pumped to the first refrigerant C1 side, the first refrigerant C1 is heated, and the underground heat source heat exchanger 45 functions 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 control 60 The operation of the composite heat source heat pump device 1 can be controlled in response to the signal from.

When performing the defrosting operation of the air heat source heat exchanger 55, 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. Perform frost operation.
The predetermined defrosting rotation speed of the heating circulation pump 32 is set lower than the rotation speed during the heating operation. For example, when the rotational speed in the heating operation is 3500 rpm, the defrosting rotational speed of the heating circulation pump 32 can be 2500 rpm lower than 3500 rpm.

  In the present embodiment, the rotation speed of the heating circulation pump 32 during heating operation is set to 3500 rpm, and the defrosting rotation speed of the heating circulation pump 32 during the defrosting operation is set to 2500 rpm. The rotational speed of the heating circulation pump 32 and the defrosting rotational speed in the heating operation are not limited to the required heating output while taking into consideration the specifications of the heat pump device, the performance of the compressor, the installation environment, the thermal load, etc. It is set as appropriate in consideration of the balance with the defrosting operation time.

The defrosting operation is an operation of supplying the high-temperature second refrigerant C2 compressed by the second compressor 53 to the air heat source heat exchanger 55 to defrost the air heat source heat exchanger 55.
As shown in FIG. 3, the form of the defrosting operation is a form in which the second refrigerant C2 is circulated in the direction opposite to that during the heating operation (see FIG. 1) for defrosting.

  Specifically, the defrosting operation shown in FIG. 3 is performed by expanding the second expansion valve 54 to a predetermined opening, that is, until the opening is fully opened, and removing the four-way valve 58. It switches to the state at the time of frost operation so that the flow direction of the second refrigerant C2 is opposite to the flow direction of the second refrigerant C2 during the heating operation, and the high-temperature second refrigerant C2 discharged from the second compressor 53 is changed. Then, the air heat source heat exchanger 55 is supplied to melt the frost generated in the air heat source heat exchanger 55. The second refrigerant C2 that has fallen in temperature due to heat exchange with frost in the air heat source heat exchanger 55 and has flowed out of the air heat source heat exchanger 55 passes through the second expansion valve 54 without being depressurized by the second expansion valve 54. It passes through the second heating heat exchanger 51 and returns to the second compressor 53 again. During the defrosting operation, in the second heating heat exchanger 51, heat exchange is performed between the second refrigerant C2 and the circulating liquid L, and the heat of the circulating liquid L is absorbed by the second refrigerant C2 side to generate an air heat source. It is used as heat for defrosting the heat exchanger 55.

  The start of the defrosting operation is, for example, whether or not the outside air temperature detected by the outside air temperature sensor 57 or the outside air temperature and the refrigerant temperature detected by the second refrigerant temperature sensor 52b has reached a predetermined defrosting start condition. If the control device 6 determines that it has reached the defrosting start condition, the defrosting operation can be started. Completion of the defrosting operation controls 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 temperature sensor 52b has reached a predetermined defrosting termination condition. When the device 6 determines that the defrosting end condition has been reached, the defrosting operation can be ended.

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 40 using 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 device 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.

  In the defrosting operation, as described above with reference to FIG. 3, the second expansion valve 54 is fully opened and the four-way valve 58 is switched to the state during the defrosting operation so that the flow direction of the second refrigerant C2 is changed. The flow direction of the second refrigerant C2 during the heating operation is reversed, and the high-temperature second refrigerant C2 discharged from the second compressor 53 is directly supplied to the air heat source heat exchanger 55 to supply the air heat source. The frost generated in the heat exchanger 55 is melted, and the second refrigerant C2 flowing out of the air heat source heat exchanger 55 is allowed to pass through the second expansion valve 54 without being depressurized by the second expansion valve 54. The exchanger 51 is circulated and returned to the second compressor 53 again.

  During this defrosting operation, in the second heating heat exchanger 51, heat exchange is performed between the second refrigerant C2 and the circulating fluid L, and the heat of the circulating fluid L is absorbed into the second refrigerant C2 side, Although heat is used for defrosting of the air heat source heat exchanger 55, the heating circulation pump 32 when performing the defrosting operation is the rotational speed during the heating operation before the defrosting operation is performed. It is driven at a predetermined defrosting rotation speed lower than that. Here, it is assumed that the temperature of the circulating liquid L flowing into the first heating heat exchanger 41 is constant, and a constant amount of heat is given from the first refrigerant C1 to the circulating liquid L in the first heating heat exchanger 41. Since the circulating flow rate of the circulating liquid L per unit time decreases and the temperature efficiency increases when the rotational speed of the heating circulation pump 32 is lowered to 2500 rpm, for example, compared to 3500 rpm, the first heating heat The temperature of the circulating liquid L flowing out of the exchanger 41 is increased. Therefore, when the heating circulation pump 32 is driven at a predetermined defrosting rotation speed during the defrosting operation, the circulation flow rate of the circulating fluid L per unit time is reduced as compared with the heating operation before the defrosting operation is performed. Then, the temperature of the circulating liquid L flowing out from the first heating heat exchanger 41 becomes high, that is, the temperature of the circulating liquid L flowing into the second heating heat exchanger 51 becomes high. , The heat absorbed from the circulating fluid L side to the second refrigerant C2 side increases, and the temperature of the second refrigerant C2 also rises by that amount, and is discharged from the second compressor 53 and supplied to the air heat source heat exchanger 55. Therefore, the frost generated in the air heat source heat exchanger 55 is easily melted. Accordingly, the rotational speed of the heating circulation pump 32 at the time of the defrosting operation is set to a predetermined value that is set lower than that at which the rotational speed is the same as that at the heating operation before the defrosting operation is performed. The defrosting operation time can be shortened when driven at the frost rotation speed.

Further, during the defrosting operation, the first compressor 43 of the first heat pump circuit 40 is driven at the maximum rotational speed (for example, 90 rps), and the heating of the second heat pump circuit 50 before the defrosting operation is performed. Since the heating output of the first heat pump circuit 40 is increased so as to cover the output as much as possible, in the first heating heat exchanger 41, the heat absorbed from the first refrigerant C1 side to the circulating fluid L side increases. Since the temperature of the circulating liquid L flowing out from the first heating heat exchanger 41 can be increased, the temperature of the circulating liquid L flowing into the second heating heat exchanger 51 becomes high and flows out of the second heating heat exchanger 51. The circulating fluid L can be kept at a high temperature, the temperature drop of the circulating fluid L supplied to the heat radiating terminal 36 can be suppressed as much as possible, and the feeling of heating can be prevented as much as possible. Furthermore, since the temperature of the circulating fluid L flowing out from the first heating heat exchanger 41 can be increased, the temperature of the circulating fluid L flowing into the second heating heat exchanger 51 is increased, so that the second heating heat exchanger In 51, the heat absorbed from the circulating fluid L side to the second refrigerant C2 side increases, and the temperature of the second refrigerant C2 rises by that amount, and is discharged from the second compressor 53 and supplied to the air heat source heat exchanger 55. Since the temperature of the second refrigerant C2 to be raised also increases, frost generated in the air heat source heat exchanger 55 is easily melted, and the time during which the defrosting operation is performed can be shortened.
Note that the maximum rotation speed of the first compressor 43 is not strictly applied, and includes an allowable rotation speed and a value that allows for a safety factor from the allowable rotation speed.

  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 temperature sensor 52b reached | attained predetermined defrost termination conditions, defrost operation | movement , The four-way valve 58 is switched to the heating operation state (see FIG. 1), and the rotation speed of the heating circulation pump 32 is returned to the rotation speed during the heating operation. The operation returns to the heating operation in which both the first heat pump circuit 40 and the second heat pump circuit 50 are operated.

  As described above, the composite heat source heat pump device 1 according to the embodiment of the present invention can shorten the defrosting operation time and does not impair the feeling of heating as much as possible.

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 58 four-way valve 61 underground heat pump control device 62 air heat heat pump control device 63 defrosting operation control device C1 first 1 refrigerant C2 2nd refrigerant L Circulating fluid

Claims (2)

A heating circulation circuit having a heating circulation pump that circulates the circulating fluid to the heat radiating 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, a second expansion valve that depressurizes the second refrigerant that has flowed out of the second heating heat exchanger, and a switching valve that switches a flow direction of the second refrigerant. A second heat pump circuit that heats the circulating fluid through the second heating heat exchanger;
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 switching valve is switched so that the flow direction of the second refrigerant is opposite to the flow direction of the second refrigerant during the heating operation, and the second refrigerant discharged from the second compressor is changed to the air. A defrosting operation for performing a defrosting operation for melting the frost generated in the air heat source heat exchanger by supplying to the heat source heat exchanger and driving the heating circulation pump at a predetermined defrosting rotation speed during the defrosting operation. Having control means,
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 than during the heating operation,
The predetermined defrosting rotation speed of the heating circulation pump is a rotation speed set lower than the rotation speed at the time of the heating operation, the circulating liquid is circulated through the heat radiating terminal, and heating by the heat radiating terminal is continued. Performing the defrosting operation at
A combined heat source heat pump device. The controller is
Driving the first compressor of the first heat pump circuit at a maximum rotational speed during the defrosting operation;
The composite heat source heat pump device according to claim 1.

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