JP6599812B2 - Combined heat source heat pump device - Google Patents

Description

  The present invention relates to a composite heat source heat pump device, and in particular, when performing a defrosting operation for melting frost adhering to a heat source side heat exchanger of a second heat pump circuit that uses outside air as a heat source during heating operation, The present invention relates to a composite heat source heat pump device that covers heating operation by an operation of a first heat pump circuit that uses another heat source.

  Conventionally, a plurality of heat pump circuits in which a compressor, a load side heat exchanger, an expansion valve, and a heat source side heat exchanger are annularly connected by refrigerant piping (first heat pump circuit using a heat source different from the outside air and A second heat pump circuit that uses outside air as a heat source), the first load-side heat exchanger of the first heat pump circuit and the second load-side heat exchanger of the second heat pump circuit are arranged in series; In a combined heat source heat pump apparatus that performs a heating operation for heating a circulating liquid in a load-side heat exchanger of a heat pump circuit and supplying the circulating liquid to a heat radiating terminal installed in the room to heat the room, When the defrosting start condition for starting the defrosting operation for melting the frost generated in the heat source side heat exchanger of the heat pump circuit is satisfied, the first heat pot is used to back up the heating operation at that time. To start driving the compressor flop circuit, since to start driving the compressor of the first heat pump circuit after a predetermined time, there is one that starts the defrosting operation. (For example, refer to Patent Document 1.)

JP, 2015-161467, A

  By the way, in this conventional one, the case where the defrosting start condition is satisfied is a state in which a lot of frost has adhered to the heat source side heat exchanger of the second heat pump circuit. The heat exchange efficiency in the heat source side heat exchanger of the heat pump circuit is deteriorated, and the heating capacity of the second heat pump circuit is lower than the heating capacity that can be normally exhibited.

  As described above, since the COP (energy consumption efficiency) is deteriorated when the compressor is driven at the rotation speed up to that time despite the heating capacity is reduced, the defrosting start condition is satisfied. Until the defrosting operation is started, there is a problem that the heating operation is continued in a state where the COP is low.

  The present invention has been made in view of such a background, and even when the defrosting operation is started during the heating operation, the composite heat source capable of suppressing the decrease in COP while continuing the heating operation. An object is to provide a heat pump device.

In order to solve the above-described problems, the present invention provides a load-side circulation circuit having a load-side circulation pump that circulates a load-side circulation liquid in a heat radiating terminal, and a condenser disposed in the load-side circulation circuit. The first load-side heat exchanger as the first load-side heat exchanger, the second load-side heat exchanger as the condenser disposed in the load-side circulation circuit, and the first heat-side circulating from the predetermined heat source other than the outside air. 1st heat source side heat exchanger which heats 1 refrigerant | coolant, 1st compressor which compresses said 1st refrigerant | coolant, and 1st load side heat exchanger which distribute | circulates said 1st refrigerant | coolant discharged from this 1st compressor And a first expansion valve that depressurizes the first refrigerant flowing out of the first load side heat exchanger, and heats the load side circulating fluid via the first load side heat exchanger. 1 heat pump circuit and a second heat source that heats a second refrigerant that collects heat from outside air and circulates in the circuit A heat exchanger; a second compressor that compresses the second refrigerant; a second load-side heat exchanger that distributes the second refrigerant discharged from the second compressor; and the second load-side heat exchange. A second expansion valve that depressurizes the second refrigerant that has flowed out of the vessel, and a switching valve that switches a flow direction of the second refrigerant, and the load-side circulating fluid via the second load-side heat exchanger. A second heat pump circuit for heating the load side, a temperature sensor for detecting the temperature of the load-side circulating fluid circulating in the load-side circulation circuit, and a control device for controlling the operation, the first load-side heat exchanger Is arranged in series upstream of the second load-side heat exchanger in the load-side circulation circuit, and the control device is detected by the temperature sensor during the heating operation for heating the load-side circulation liquid. The first circulating temperature is adjusted so that the temperature of the load-side circulating fluid reaches a target hot water temperature. And controlling the rotational speed of the compressor or the second compressor, further, the control device, during the heating operation of heating the load side circulating liquid by operating at least the second heat pump circuit, starting a predetermined defrost When the condition is satisfied, after the defrost preparation operation for increasing the rotation speed of the first compressor of the first heat pump circuit to the maximum rotation speed is performed for a predetermined time, the switching valve is moved to the second refrigerant. The second refrigerant discharged from the second compressor is supplied to the second heat source side heat exchanger by switching so that the flow direction of the refrigerant is opposite to the flow direction of the second refrigerant during the heating operation. In the composite heat source heat pump device that performs a defrosting operation for melting frost generated in the second heat source side heat exchanger, the control device is configured to control the second compressor of the second heat pump circuit in the defrost preparation operation. Rotation speed The controller is driven at a predetermined rotational speed for defrosting that is lower than that in the previous heating operation , and the control device is detected by the temperature sensor during the defrost preparation operation. The temperature of the load-side circulating fluid detected by the temperature sensor is not controlled without adjusting the rotation speeds of the first compressor and the second compressor so that the temperature of the load-side circulating fluid becomes the target hot water temperature. Regardless of whether the rotational speed of the first compressor is fixed and driven at the maximum rotational speed, the rotational speed of the second compressor is fixed and driven at a preset predetermined rotational speed for defrosting. It was supposed to be.

According to the first aspect of the present invention, when the defrosting start condition is established during the heating operation, the rotation speed of the first compressor is increased to the maximum rotation speed as the defrost preparation operation, and after a predetermined time has elapsed. by was to start the defrosting operation, to the first heat pump circuit over time to put out a stable heating capacity waits for the start of the defrosting operation, the maximum rotational speed of the rotational speed of the first compressor Since it is driven to increase and the heating capacity decrease of the second heat pump circuit is covered quickly, the stable heating capacity is ensured and the hot water temperature of the load-side circulating liquid supplied to the heat radiating terminal is not lowered . Ru can start defrosting operation in a state that can continue the heating operation while securing a stable heating capacity. Furthermore, the control device lowers the rotation speed of the second compressor of the second heat pump circuit in the defrost preparation operation, and drives it at a predetermined defrosting rotation speed that is set in advance . Thus, the operation in a state where the second heat source side heat exchanger is frosted, that is, the operation in a state where the heating capacity is reduced, is limited, and the power consumption of the second compressor is reduced to suppress the reduction of the COP. it is Ru can. In addition, during the defrost preparation operation, the control device performs control to adjust the rotation speeds of the first compressor and the second compressor so that the temperature of the load-side circulating fluid detected by the temperature sensor becomes the target hot water temperature. Regardless of the temperature of the load-side circulating fluid detected by the temperature sensor, the rotation speed of the first compressor is fixed and driven at the maximum rotation speed, and the rotation speed of the second compressor is set to a preset value. It is fixed and driven at a predetermined number of revolutions for frost. With such control, the temperature of the load-side circulating fluid may exceed the target hot water temperature, but when the defrosting operation is started, the heat of the load-side circulating fluid is absorbed by the second refrigerant in the second load-side heat exchanger. Since the warm water temperature of the load-side circulating fluid is lowered, by performing the rotation speed fixing control of the first compressor and the second compressor, the load-side circulating fluid is subjected to the load side during the defrost preparation operation period before entering the defrost operation. leave raised hot water temperature of the circulating fluid, it shall be able to reduce the drop in temperature of hot water in the load-side circulating fluid during the defrosting operation.

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 the same embodiment. Explanatory drawing explaining the operation | movement at the time of the heating operation which concerns on the same embodiment. Explanatory drawing explaining operation | movement in case defrost operation is performed during the heating operation which concerns on the same embodiment. The time chart which shows operation | movement of each part in case defrost operation is performed during the heating operation which concerns on the embodiment. The other time chart which shows operation | movement of each part in case defrosting operation is performed during the heating operation which concerns on the embodiment.

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 operates the load side circulation circuit 30 for circulating the load side circulation liquid L (for example, water or antifreeze liquid) through the heat radiating terminal 36, the heat source side circulation circuit 20, and the operations of the composite heat source heat pump device 1. It has a control device 6 (61, 62) as a control means for controlling and a remote controller 60 that sends a signal to the control device 6, and performs heating or cooling of the room where the heat radiating terminal 36 is installed.

  As shown in FIG. 2, the composite heat source heat pump device 1 according to the present embodiment heats or cools the load-side circulating liquid L on the heat radiating terminal 36 side using a heat source different from the outside air, here, a ground heat source. The second load side heat exchange of the first heat pump circuit 50 that heats or cools the first load side heat exchanger 41 of the first heat pump circuit 40 and the load side circulating fluid L on the side of the heat radiation terminal 36 using outside air as a heat source. The first load-side heat exchanger 41 is disposed upstream of the second load-side heat exchanger 51 with respect to the flow of the load-side circulating fluid L that circulates through the load-side circulation circuit 30. . The composite heat source heat pump device 1 can function as a heating device and a cooling device, but in this embodiment, components and operations when mainly used as a heating device will be described.

  The first heat pump circuit 40 includes a first compressor 43 having a variable rotation speed for compressing the first refrigerant C1, a first four-way valve 44, a first load-side heat exchanger 41, and a first decompression unit. An expansion valve 45, a first heat source side heat exchanger 46, and a first refrigerant pipe 42 that connects these in an annular shape are configured.

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

  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. The first refrigerant pipe 42 from the first expansion valve 45 to the first heat source side heat exchanger 46 detects the temperature of the first refrigerant C1 on the low pressure side (heating operation) or the high pressure side (cooling operation). 1 refrigerant temperature sensor.

  The second heat pump circuit 50 includes a second compressor 53 having a variable rotation speed that compresses the second refrigerant C2, a second four-way valve 54, a second load-side heat exchanger 51, and a second decompression unit. The second heat source side heat exchanger 57 that performs heat exchange between the expansion valve 55 and the outside air that is sent by the operation of the blower fan 56, and a second refrigerant pipe 52 that connects these in an annular shape are configured.

The second four-way valve 54 provided in the second refrigerant pipe 52 has a function as a switching valve for switching the flow direction of the second refrigerant C2 in the second heat pump circuit 50 and is discharged from the second compressor 53. A state in which the second refrigerant C2 is circulated in the order of the second load side heat exchanger 51, the second expansion valve 55, and the second heat source side heat exchanger 57 to form a flow path returning to the second compressor 53 (heating operation) And the second refrigerant C2 discharged from the second compressor 53 are circulated in the order of the second heat source side heat exchanger 57, the second expansion valve 55, and the second load side heat exchanger 51, 2 It can be switched to a state in which a flow path returning to the compressor 53 is formed (a state during a defrosting operation or a cooling operation).
In this embodiment, when the 2nd heat source side heat exchanger 57 becomes low temperature and it forms frost, the 2nd refrigerant | coolant C2 discharged from the 2nd compressor 53 flows toward the 2nd heat source side heat exchanger 57. Then, the second four-way valve 54 is switched, and the frost generated in the second heat source side heat exchanger 57 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 temperature of the second refrigerant C2 provided in the second refrigerant pipe 52 from the expansion valve 55 to the second heat source side heat exchanger 57 and on the low pressure side (during heating operation) or high pressure side (during defrosting operation or cooling operation). The reference numeral 52c is an outside air temperature sensor that detects 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 first load side heat exchanger 41, the first heat source side heat exchanger 46, and the second load side heat exchanger 51 are constituted by, for example, plate heat exchangers. 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 such as a circulating liquid are alternately formed with each heat transfer plate as a boundary. ing.

  The heat source side circulation circuit 20 serves as a heat source for exchanging heat with the heat source side circulation pump 22 having a variable rotation speed, the first heat source side heat exchanger 46, and the first refrigerant C1 flowing through the first heat source side heat exchanger 46. A ground heat exchanger 23 installed (in the ground in this example) is connected in a ring shape by a heat source side pipe 21 as a heat medium pipe. The heat source side circulation pump 22 circulates the heat source side circulating fluid H (water or antifreeze) as a heat medium in the heat source side piping 21, and also stores the heat source side circulating fluid H to adjust the pressure of the heat source side circulation circuit 20. A heat source side cistern 24 to be adjusted is provided. The underground heat exchanger 23 is not limited to be provided in the ground, and may be provided in a water source such as a lake, a reservoir, a well, or the like.

  The load-side circulation circuit 30 includes a first load-side heat exchanger 41, a second load-side heat exchanger 51, and a heat radiating terminal 36 as a load terminal such as a floor heating panel, a panel convector, and a fan coil. The side pipes 31 are connected in an annular shape in order from the upstream side. The load-side piping 31 is provided with a load-side circulation pump 32 that circulates the load-side circulating fluid L in the load-side circulation circuit 30, and each load-side piping 31 branched for each heat radiating terminal 36 includes Thermally operated valves 33 are provided as opening and closing means for controlling the supply of the load-side circulating fluid L to the heat radiating terminal 36 by opening and closing, and the room temperature at which the heat radiating terminal 36 is installed becomes a predetermined temperature. The opening / closing is controlled as described above, and is provided outside the heat radiating terminal 36 in FIG. 2, but may be built in the heat radiating terminal 36. 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.

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

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

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

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

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

  The geothermal heat pump control device 61 controls the rotational speed of the load-side circulation pump 32. In particular, in this example, when only the heating operation is performed, the rotation speed of the load-side circulation pump 32 is controlled so as to rotate at a constant speed (a constant rotation speed). When the defrosting operation is performed, the rotational speed of the load-side circulation pump 32 is controlled at a predetermined defrosting rotational speed that is lower than the constant rotational speed during the heating operation. For example, if the rotation speed when only the heating operation is performed is 3500 rpm, the rotation speed during the defrosting operation can be 2500 rpm, but the present invention is not limited to this, and only the heating operation is performed. The rotational speed of the load-side circulation pump 32 and the rotational speed during the defrosting operation are appropriately set in consideration of the specifications of the composite heat source heat pump device 1, the performance of the compressor, the installation environment, the thermal load, and the like. The

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

  Further, the air heat heat pump control device 62 controls the valve opening degree of the second expansion valve 55 according to the refrigerant discharge temperature of the second refrigerant C2 detected by the second refrigerant discharge temperature sensor 52a. Particularly in this example, the second expansion is performed so that the refrigerant discharge temperature of the second refrigerant C2 detected by the second refrigerant discharge temperature sensor 52a becomes, for example, a control target refrigerant discharge temperature corresponding to the set temperature of the remote controller 60. The valve opening degree of the valve 55 is controlled. In addition, this air heat heat pump control apparatus 62 and the underground heat pump control apparatus 61 control the 1st expansion valve 45 or the 2nd expansion valve 55 used as object, cooperating with each other as needed.

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

  In addition, when it is determined that frost is attached to the second heat source side heat exchanger 57 during the heating operation, the air heat heat pump control device 62 performs a defrosting operation for melting the frost.

  The form of the defrosting operation is a form in which the second refrigerant C2 is circulated in the opposite direction to that during the heating operation. Specifically, the defrosting operation is performed with respect to the second expansion valve 55 than during the heating operation before the defrosting operation. While expanding to a predetermined opening (for example, fully open), the second four-way valve 54 is switched to the state during the defrosting 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. In this way, the second refrigerant C2 discharged from the second compressor 53 is directly supplied to the second heat source side heat exchanger 57 to melt the frost generated in the second heat source side heat exchanger 57. The second heat source side heat exchanger 57 passes through the second expansion valve 55 without being depressurized by the second expansion valve 55 whose temperature has decreased due to heat exchange with frost, and flows through the second load side heat exchanger 51. Then, it returns to the second compressor 53 again.

  The start of the defrosting operation is, for example, whether or not the outside air temperature detected by the outside air temperature sensor 52c has reached a preset defrosting start temperature, or the refrigerant temperature detected by the second refrigerant temperature sensor 52b is Whether or not the set defrost start temperature has been reached, or the outside air temperature detected by the outside air temperature sensor 52c and the refrigerant temperature detected by the second refrigerant temperature sensor 52b have respectively reached a preset defrost start temperature. Whether or not the control device 6 (for example, the air heat heat pump control device 62) determines, that is, the control device 6 determines whether or not a predetermined defrost start condition is satisfied, and the defrost start condition is satisfied. If it is determined, the defrosting operation can be started. In addition, whether the defrosting operation has been completed has the temperature of the second refrigerant C2 that has passed through the second heat source side heat exchanger 57 detected by the second refrigerant temperature sensor 52b reached a preset defrosting end temperature. Is determined by the control device 6 (for example, the air heat heat pump control device 62), that is, the control device 6 determines whether or not a predetermined defrosting end condition is satisfied, and determines that the defrosting end condition is satisfied. Then, the defrosting operation can be finished.

  Next, the operation | movement at the time of the heating operation of the composite heat source heat pump apparatus 1 shown to FIG. 1 and FIG. 2 is demonstrated using FIG. 3 and FIG. The heating operation may be performed by operating either the first heat pump circuit 40 or the second heat pump circuit 50, or by operating both the first heat pump circuit 40 and the second heat pump circuit 50. Here, the case where both the first heat pump circuit 40 and the second heat pump circuit 50 are operated will be described. Note that the arrows in FIGS. 3 and 4 indicate the direction in which the refrigerant and the circulating fluid flow.

  When an instruction for heating the room by the heat radiating terminal 36 is given from the remote controller 60, first, the control device 6 first sets the first compressor 43 of the underground heat pump unit 4 and the air heat heat pump device 5 based on the outside air temperature. One of the two compressors 53 is set as a main power source, and the other is set as an auxiliary power source.

  Specifically, if the outside air temperature detected by the outside air temperature sensor 52c is equal to or higher than a predetermined reference temperature (for example, 5 ° C.), the air heat heat pump unit 5 has higher heat collection efficiency. If the first compressor 43 is set as an auxiliary power source as the main power source and the outside air temperature detected by the outside air temperature sensor 52c is lower than a predetermined reference temperature (for example, 5 ° C.), the underground heat pump unit 4 Since the heat collection efficiency is higher, the first compressor 43 is set as the main power source and the second compressor 53 is set as the auxiliary power source.

  And the control apparatus 6 switches a flow path so that the 1st four-way valve 44 and the 2nd four-way valve 54 may be in the state at the time of heating operation, the 1st compressor 43, the 1st expansion valve 45, and the heat-source side circulation pump 22 Then, the second compressor 53, the second expansion valve 55, the blower fan 56, and the load side circulation pump 32 are driven to start the heating operation. At this time, the thermal valve 33 is also opened.

  During the heating operation, in the first heat pump circuit 40, the high-temperature and high-pressure gaseous first refrigerant C1 compressed by the first compressor 43 is discharged from the first compressor 43, and the first refrigerant C1 serves as a condenser. In the functioning first load-side heat exchanger 41, heat exchange is performed with the load-side circulating fluid L flowing through the load-side circulating circuit 30 to release heat to the load-side circulating fluid L, and in a gas-liquid mixed state while heating. It changes to a high-pressure refrigerant. Then, the first refrigerant C1 in this state is decompressed by the first expansion valve 45 to become a low-pressure refrigerant and easily evaporates. In the first heat source side heat exchanger 46 functioning as an evaporator, the heat source side circulation circuit Heat exchange is performed with the heat-source-side circulating fluid H flowing through 20, and heat is absorbed from the heat-source-side circulating fluid H to become a low-temperature / low-pressure gaseous first refrigerant C1 and return to the first compressor 43 again.

  On the other hand, in the second heat pump circuit 50, the high-temperature and high-pressure gaseous second refrigerant C2 compressed by the second compressor 53 is discharged from the second compressor 53, and the second refrigerant C2 functions as a condenser. In the two-load-side heat exchanger 51, heat is exchanged with the load-side circulating fluid L flowing through the load-side circulating circuit 30, and heat is released to the load-side circulating fluid L to heat and heat the gas in a gas-liquid mixed state while heating. To change. Then, the second refrigerant C2 in this state is depressurized in the second expansion valve 55 to become a low-pressure refrigerant and easily evaporates. In the second heat source side heat exchanger 57 functioning as an evaporator, It exchanges heat with the outside air sent by operation, absorbs heat from the outside air, becomes a low-temperature, low-pressure gaseous second refrigerant C2, and returns to the second compressor 53 again.

  Further, in the heat source side circulation circuit 20, the ground heat is collected by the underground heat exchanger 23, and the heat source side circulation liquid H having the heat is driven by the heat source side circulation pump 22 to be the first heat source side heat exchanger. 46. Then, heat exchange is performed between the first refrigerant C1 and the heat source side circulating fluid H in the first heat source side heat exchanger 46, and the underground heat collected in the underground heat exchanger 23 is the first refrigerant C1 side. The first refrigerant C1 is heated and evaporated.

  In the load-side circulation circuit 30, the load-side circulating liquid L that has flowed into the first load-side heat exchanger 41 by driving the load-side circulation pump 32 that is driven at a constant rotational speed is a first load that functions as a condenser. After heat exchanged with the first refrigerant C1 in the side heat exchanger 41, heat was exchanged with the second refrigerant C2 in the second load side heat exchanger 51 functioning as a condenser, and further heated and heated. Thereafter, the load-side circulating fluid L is supplied to the heat radiating terminal 36 to heat the room, and the temperature-decreased load-side circulating fluid L radiated from the heat radiating terminal 36 is returned to the first load-side heat exchanger 41 again. And return.

  When the defrosting operation is performed during the heating operation, the second four-way valve 54 is switched from the state during the heating operation to the state during the defrosting operation, and as shown in FIG. The flow direction is opposite to the flow direction of the second refrigerant C2 during the heating operation.

  Next, as a characteristic operation, the operation of the composite heat source heat pump device 1 when the defrosting operation is performed during the heating operation will be described with reference to the time chart of FIG. Here, the second compressor 53 is set as a main power source and the first compressor 43 is set as an auxiliary power source, and both the first heat pump circuit 40 and the second heat pump circuit 50 are operated to perform heating. It is assumed that the operation is performed, and the time t0 in the time chart of FIG. 5 is driven at a rotation speed of 90 rps where the rotation speed of the second compressor 53 is the maximum rotation speed and a rotation speed of the first compressor 43 is 50 rps. It is an arbitrary time in the state where

  During the heating operation in which the load-side circulating liquid L heated by the first load-side heat exchanger 41 and the second load-side heat exchanger 51 is supplied to the heat radiation terminal 36 by driving the load-side circulation pump 32. On the other hand, when the control device 6 determines that the defrosting start condition is established from the outside air temperature detected by the outside air temperature sensor 52c (time t1), it enters the defrost preparation operation (time t1 to time t1).

  When it is determined that the defrosting start condition is satisfied, the control device 6 reduces the rotation speed of the second compressor 53 from the maximum rotation speed of 90 rps up to that time as a defrost preparation operation. While driving at a predetermined frost speed of 50 rps (time t <b> 1), the rotation speed of the first compressor 43 is increased from the previous 50 rps and driven at a maximum speed of 90 rps (time t <b> 1). . It should be noted that the maximum rotational speeds of the first compressor 43 and the second compressor 53 are not intended to be strictly applied, and include the allowable rotational speed and those that allow for a safety factor from the allowable rotational speed.

  Here, the situation where the defrosting start condition is satisfied is a state in which a lot of frost has adhered to the second heat source side heat exchanger 57 of the second heat pump circuit 50, and in such a state. The heat exchange efficiency in the second heat source side heat exchanger 57 is poor, and the heating capability (heating output) of the second heat pump circuit 50 is also lower than the heating capability that can be normally exhibited. Although the temperature of the hot water to be reduced also decreases, the rotation speed of the second compressor 53 of the second heat pump circuit 50 is, for example, the maximum rotation speed in order to supply the target heat water temperature to the heat radiating terminal 36. It is in a driven state. When the second compressor 53 is driven at the maximum rotational speed even though the heating capacity is reduced, COP (here, COP = heating capacity / energy consumption efficiency represented by the power consumption of the compressor) In this embodiment, as described above, when it is determined that the defrosting start condition is satisfied, the consumption of the second compressor 53 is reduced by reducing the rotation speed of the second compressor 53. The power can be reduced to suppress the reduction of COP. In addition, when the rotation speed of the 2nd compressor 53 is reduced, a heating capability will also fall, but the degree is considerably small compared with the fall of the heating capability by the 2nd heat source side heat exchanger 57 having been frosted.

  Further, when it is determined that the defrosting start condition is satisfied, not only the rotation speed of the second compressor 53 is decreased, but also the first compressor 43 is covered to cover the heating capacity decrease of the second heat pump circuit 50. Since the number of rotations is increased to the maximum number of rotations, the heating operation can be continued so as to ensure a stable heating capacity and not to lower the hot water temperature of the load-side circulating liquid L supplied to the heat radiating terminal 36. .

  Further, during the period from time t1 to time t2 when the defrost preparation operation is performed, the first temperature is set so that the temperature of the load-side circulating fluid L detected by the return temperature sensor 34 that is normally performed during the heating operation becomes the target hot water temperature. The control of adjusting the rotational speeds of the compressor 43 and the second compressor 53 is not performed, and the rotational speed of the first compressor 43 is the maximum rotational speed regardless of the temperature of the load-side circulating fluid L detected by the return temperature sensor 34. The rotation speed of the second compressor 53 is fixed and driven at a preset predetermined rotation speed for defrosting. With such control, the temperature of the load-side circulating fluid L may exceed the target hot water temperature, but when the defrosting operation is started, the heat of the load-side circulating fluid L is supplied to the second load-side heat exchanger 51 by the second. Since the hot water temperature of the load-side circulating fluid L is absorbed by the refrigerant C2, the defrosting before entering the defrosting operation is performed by performing the rotation speed fixing control of the first compressor 43 and the second compressor 53. The warm water temperature of the load-side circulating fluid L can be increased during the preparatory operation period, and the drop in the warm water temperature of the load-side circulating fluid L during the defrosting operation can be reduced.

  When the controller 6 determines that the above-described defrost preparation operation has been performed for a preset first time (time t1 to t2), the control device 6 stops driving the second compressor 53 (time t2), and 2 Stop driving the expansion valve 55 and the blower fan 56, temporarily stop the operation of the second heat pump circuit 50, and reduce the rotational speed of the load-side circulation pump 32 from the previous 3500 rpm, Drive at frost rotation speed (2500 rpm here) (time t2).

  Here, when the second heat pump circuit 50 is stopped, the opening of the second expansion valve 55 is fully opened, and the second preset time (time t2 to time t3) is waited for. However, this is because the opening of the second expansion valve 55 is fully opened and the passage of a predetermined time is waited, whereby the pressure on the discharge side (high pressure side) of the second compressor 53 and the pressure difference on the suction side (low pressure side). This is performed in order to safely start the functional components such as the second compressor 53 at the next start-up. In the present embodiment, the operation of the second heat pump circuit 50 is stopped during the period from time t2 to time t3. During this period, the opening degree of the second expansion valve 55 is maintained while the second compressor 53 is driven. Is fully opened, and waiting for a preset second time (time t2 to time t3) to elapse, the pressure on the discharge side (high pressure side) of the second compressor 53 and the suction side (low pressure side) Since the differential pressure can be eliminated, it is also possible to shift to the next operation while the second heat pump circuit 50 is operated.

  Subsequently, when the control device 6 determines that a preset second time (time t2 to time t3) has elapsed since the second heat pump circuit 50 was stopped, the defrosting operation is performed on the second four-way valve 54. Switch to the hour state and start the defrosting operation (time t3). At this time, since the load-side circulation pump 32 is driven and the first heat pump circuit 40 is also operating, the defrosting operation is performed in a state where the heating operation is continued.

  As described above, in the defrosting operation, the second expansion valve 55 is fully opened and the second four-way valve 54 is switched to the state during the defrosting operation so that the flow direction of the second refrigerant C2 is during the heating operation. The second refrigerant C2 discharged from the second compressor 53 driven at 50 rps is directly supplied to the second heat source side so as to be opposite to the flow direction of the second refrigerant C2 (see the second heat pump circuit 50 in FIG. 4). Supplied to the heat exchanger 57 to melt frost generated in the second heat source side heat exchanger 57, and the second refrigerant C2 flowing out from the second heat source side heat exchanger 57 is decompressed by the second expansion valve 55. Without passing through the second expansion valve 55, the second load-side heat exchanger 51 is circulated and returned to the second compressor 53 again.

  During the defrosting operation, in the second load side heat exchanger 51, heat exchange is performed between the second refrigerant C2 and the load side circulating fluid L, and the heat of the load side circulating fluid L is transferred to the second refrigerant C2 side. Although the heat is absorbed and the heat is used for defrosting of the second heat source side heat exchanger 57, the rotational speed of the load-side circulation pump 32 during the defrosting operation is the defrosting operation. Is driven at a predetermined defrosting rotation speed (here 2500 rpm) lower than the rotation speed (here, 3500 rpm) during the heating operation. Here, the temperature of the load-side circulating fluid L flowing into the first load-side heat exchanger 41 is constant, and a constant amount of heat is given from the first refrigerant C1 to the load-side circulating fluid L in the first load-side heat exchanger 41. Assuming that the rotational speed of the load-side circulation pump 32 is lower than 2500 rpm, for example, 3500 rpm, the circulation flow rate of the load-side circulation fluid L per unit time decreases, and the temperature Since the efficiency increases, the temperature of the load-side circulating fluid L that flows out of the first load-side heat exchanger 41 increases. Therefore, when the load-side circulation pump 32 is driven at a predetermined defrosting rotation speed during the defrosting operation, the circulation flow rate of the load-side circulation liquid L per unit time is compared with that during the heating operation before the defrosting operation is performed. Since the temperature of the load-side circulating fluid L flowing out from the first load-side heat exchanger 41 increases, the temperature of the load-side circulating fluid L flowing out from the first load-side heat exchanger 41 increases. The amount of heat absorbed by the second refrigerant C2 increases, the temperature of the second refrigerant C2 rises accordingly, and the temperature of the second refrigerant C2 supplied to the second heat source side heat exchanger 57 also rises. The frost generated in the side heat exchanger 57 is also easily melted. Therefore, the defrosting operation time is shortened by driving the rotation speed of the load-side circulation pump 32 at the time of the defrosting operation at a lower defrosting rotation speed than at the time of the heating operation before the defrosting operation is performed. And the defrosting operation time is not prolonged.

  During the defrosting operation, the first compressor 43 of the first heat pump circuit 40 is driven at the maximum rotation speed (90 rps), and the temperature of the load-side circulating fluid L flowing out from the first load-side heat exchanger 41 is Therefore, the temperature of the load-side circulating fluid L flowing into the second load-side heat exchanger 51 is increased, and the temperature of the circulating fluid L flowing out of the second load-side heat exchanger 51 is also kept high. The temperature reduction of the load side circulating fluid L supplied to the heat radiating terminal 36 is suppressed as much as possible, and the heating operation can be continued so as not to impair the feeling of heating as much as possible. Furthermore, since the temperature of the load-side circulating fluid L flowing into the second load-side heat exchanger 51 becomes higher, the second load-side heat exchanger 51 absorbs heat from the load-side circulating fluid L side to the second refrigerant C2 side. As the heat increases, the temperature of the second refrigerant C2 also rises by that amount, and the temperature of the second refrigerant C2 discharged from the second compressor 53 and supplied to the second heat source side heat exchanger 57 also rises. The frost generated in the heat source side heat exchanger 57 is also easily melted, the time during which the defrosting operation is performed can be shortened, and the defrosting operation time is not prolonged.

  Then, when performing the defrosting operation, the control device 6 performs a predetermined defrosting termination condition from the temperature of the second refrigerant C2 that has passed through the second heat source side heat exchanger 57 detected by the second refrigerant temperature sensor 52b. If it is determined that the above is established, the driving of the second compressor 53 is stopped (time t4), the defrosting operation is terminated, and the operation of the second heat pump circuit 50 is once stopped.

  When the operation of the second heat pump circuit 50 is stopped at time t4, the opening degree of the second expansion valve 55 is fully open, and the preset third time (time t4 to time t5) has elapsed. This waits for the difference between the discharge side (high pressure side) and the suction side (low pressure side) of the second compressor 53 by waiting for the passage of a predetermined time with the opening of the second expansion valve 55 fully opened. This is performed in order to eliminate the pressure and to safely start the functional components such as the second compressor 53 at the next start-up. In the present embodiment, the operation of the second heat pump circuit 50 is temporarily stopped during the time t4 to t5. However, during the defrosting operation, the opening of the second expansion valve 55 is fully open, and the second compression is performed. Since there is no differential pressure between the discharge side (high pressure side) and the suction side (low pressure side) of the machine 53, when the defrosting operation is completed, the preset third time (time t4 to time t5) is omitted. Thus, it is also possible to switch the second four-way valve 54 to the state during the heating operation and shift to the next operation while operating the second heat pump circuit 50 without stopping the driving of the second compressor 53. .

  When the control device 6 determines that the third time has elapsed, the second four-way valve 54 is switched to the heating operation state, and the second compressor 53 is in the heating operation before entering the defrost preparation operation. The driving is restarted at the rotation speed (90 rps) (time t5), the driving of the second expansion valve 55 and the blower fan 56 is restarted, the operation of the second heat pump circuit 50 is restarted, and the load-side circulation pump 32 is further restarted. Is returned from the predetermined defrosting rotation speed (2500 rpm) to the rotation speed (3500 rpm) in the heating operation before the defrosting operation is performed (time t5).

  Then, when it is determined that, for example, 5 minutes have elapsed as a predetermined time (time t5 to time t6) after the operation of the second heat pump circuit 50 is restarted, the rotation speed (90 rps) of the first compressor 43 Is returned to the rotation speed (50 rps) at the time of the heating operation before entering the defrost preparation operation (from time t6), and the second heat pump circuit 50 as a main power source is brought into the heating operation state of the second heat pump circuit 50 as a main power source. It can be smoothly transitioned.

  As described above, when the control device 6 determines that the defrosting start condition is satisfied during the heating operation, the rotation speed of the second compressor 53 is decreased as compared with the previous heating operation as the defrosting preparation operation. By driving at 50 rps, which is a predetermined rotation speed for defrosting set in advance, the operation with the second heat source side heat exchanger 57 frosted, that is, the operation with a reduced heating capacity , The power consumption of the second compressor 53 can be reduced, and the reduction in COP can be suppressed. Further, when it is determined that the defrosting start condition is satisfied during the heating operation, preparation for defrosting is performed. As the operation, the rotation speed of the first compressor 43 is increased and driven, and the defrosting operation is started after a predetermined time, so that the first heat pump circuit 40 can provide a stable heating capacity. Except until Since the start of the operation is waited, the defrosting operation can be started in a state where the stable heating capacity can be secured and the heating operation can be continued, and in addition, the first compressor 43 has the maximum rotation speed as the defrost preparation operation. By driving at 90 rps, the heating capacity decrease of the second heat pump circuit 50 is covered quickly, and a stable heating capacity is secured so as not to decrease the hot water temperature of the load-side circulating fluid L supplied to the heat radiating terminal 36. The heating operation can be continued.

  In the present embodiment, the second compressor 53 is set as the main power source and the first compressor 43 is set as the auxiliary power source at the start of the heating operation, and the heating operation is performed by the first heat pump circuit 40 and the second heat pump. Assuming that both of the circuits 50 are operated, the second compressor 53 is set as the main power source and the first compressor 43 is set as the auxiliary power source at the start of the heating operation. Only the two heat pump circuit 50 may be operated. In that case, the time chart shown in FIG. 6 is obtained.

Compared with the embodiment described above, only the operation of the first compressor 43 is different in the time chart of FIG. 6, and thus the operation of the first compressor 43 will be mainly described.
When the control device 6 determines that the defrosting start condition is satisfied while the heating operation is performed by operating only the second heat pump circuit 50 (time t1), the first compressor 43 is driven. At the maximum rotation speed (90 rps), that is, as the defrost preparation operation, the rotation speed of the first compressor 43 is increased from 0 rps to 90 rps (time t1), and the first expansion valve 45 and the heat source side circulation pump 22 is started, and the operation of the first heat pump circuit 40 is started. Here, after a predetermined time has elapsed since the start of the operation of the first heat pump circuit 40, the defrosting operation is started, so that a time during which the first heat pump circuit 40 can provide a stable heating capacity elapses. Until the start of the defrosting operation, the defrosting operation can be started in a state where a stable heating capacity is ensured. In addition, the first compressor 43 has a maximum rotation speed of 90 rps as the defrosting preparation operation. To quickly cover the decrease in the heating capacity of the second heat pump circuit 50 and ensure a stable heating capacity so as not to decrease the hot water temperature of the load-side circulating fluid L supplied to the heat radiating terminal 36. The heating operation can be continued.

  And after defrosting operation | movement is complete | finished, after the control apparatus 6 restarts the drive of the 2nd compressor 53 (time t5), and restarts the action | operation of the 2nd heat pump circuit 50, predetermined time (time) set beforehand. When it is determined that the time t5 to the time t6) has elapsed, the driving of the first compressor 43 is stopped (time t6), and the driving of the first expansion valve 45 and the heat source side circulation pump 22 is stopped so as to stop the first heat pump circuit 40. Is stopped, and only the second heat pump circuit 50 is operated to return to the heating operation (from time t6). Thus, after the operation of the second heat pump circuit 50 is resumed, the operation of the first heat pump circuit 40 is continued until a certain time (time t5 to time t6) elapses. Since the operation of the first heat pump circuit 40 operated as a backup is continued until the time when the second heat pump circuit 50 having the main power source becomes capable of producing a stable heating capacity has elapsed, the heating capacity is ensured. However, it is possible to smoothly shift to the heating operation state mainly of the second heat pump circuit 50.

  Note that the present invention is not limited to the above-described embodiment, and in the present embodiment, the underground heat exchanger 23 is shown as the heat source of the underground heat pump unit 4, but as the heat source, In addition to medium heat, water heat sources such as lakes, reservoirs, and wells can also be used, and any type can be used as long as they use heat sources other than outside air, and the first heat source side heat exchanger 46 The heat source side circulating fluid H supplied to the heat source side circulating fluid H does not have to be circulated in a closed circuit such as the heat source side circulating circuit 20, and the heat source side circulating fluid H is heat exchanged by the first heat source side heat exchanger 46. It may be an open type that is discharged to the outside.

DESCRIPTION OF SYMBOLS 1 Composite heat source heat pump apparatus 6 Control apparatus 30 Load side circulation circuit 32 Load side circulation pump 36 Radiation terminal 40 1st heat pump circuit 41 1st load side heat exchanger 43 1st compressor 45 1st expansion valve 46 1st heat source side heat Exchanger 50 Second heat pump circuit 51 Second load side heat exchanger 53 Second compressor 54 Second four-way valve (switching valve)
55 Second expansion valve 57 Second heat source side heat exchanger C1 First refrigerant C2 Second refrigerant L Load side circulating fluid

Claims (1)

A load-side circulation circuit having a load-side circulation pump that circulates the load-side circulating fluid in the heat dissipation terminal;
A first load side heat exchanger as a condenser disposed in the load side circulation circuit;
A second load-side heat exchanger as a condenser disposed in the load-side circulation circuit;
A first heat source side heat exchanger that heats a first refrigerant that is collected from a predetermined heat source other than the outside air and circulates in the circuit, a first compressor that compresses the first refrigerant, and a discharge from the first compressor A first load-side heat exchanger through which the first refrigerant is circulated, and a first expansion valve that depressurizes the first refrigerant that has flowed out of the first load-side heat exchanger, and the first load A first heat pump circuit for heating the load-side circulating fluid via a side heat exchanger;
A second heat source side 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 that is discharged from the second compressor. A second load side heat exchanger for circulating the refrigerant, a second expansion valve for depressurizing the second refrigerant flowing out of the second load side heat exchanger, a switching valve for switching a flow direction of the second refrigerant, A second heat pump circuit that heats the load-side circulating fluid via the second load-side heat exchanger;
A temperature sensor for detecting the temperature of the load-side circulating fluid circulating in the load-side circulation circuit;
A control device for controlling the operation,
The first load side heat exchanger is disposed in series upstream of the second load side heat exchanger in the load side circulation circuit,
In the heating operation for heating the load-side circulating fluid, the control device is configured so that the temperature of the load-side circulating fluid detected by the temperature sensor becomes a target hot water temperature. Control the speed of the compressor,
Furthermore, the control device, when a predetermined defrosting start condition is satisfied during a heating operation in which at least the second heat pump circuit is operated to heat the load-side circulating fluid, the first heat pump circuit of the first heat pump circuit After a defrost preparation operation for driving the compressor by increasing the rotational speed to the maximum rotational speed is performed for a predetermined time, the flow direction of the second refrigerant is set to flow in the second refrigerant during the heating operation. Switching to reverse the direction, supplying the second refrigerant discharged from the second compressor to the second heat source side heat exchanger to melt the frost generated in the second heat source side heat exchanger In the combined heat source heat pump device that performs the frost operation,
In the defrost preparation operation, the control device sets a predetermined rotation for defrost that is set in advance by lowering the rotation speed of the second compressor of the second heat pump circuit than that in the previous heating operation. Drive by number ,
Further, the controller rotates the first compressor and the second compressor so that the temperature of the load-side circulating fluid detected by the temperature sensor becomes the target hot water temperature during the defrost preparation operation. No control is performed to adjust the number, the first compressor is driven at a maximum rotational speed regardless of the temperature of the load-side circulating fluid detected by the temperature sensor, and the second compression is performed. rotation speed of the aircraft composite source heat pump device being characterized in that the so that is driven by fixed beforehand predetermined rotational speed for the set defrost.

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