JP6085213B2 - Heat pump equipment - Google Patents

Description

  The present invention relates to a heat pump device that prevents freezing of antifreeze liquid in an antifreeze liquid flow path of a heat source side heat exchanger that functions as an evaporator.

  Conventionally, in this type of heat pump apparatus, as shown in FIG. 6, a heat pump unit 101 as an outdoor unit, a compressor 102, a refrigerant flow path 103a of a load side heat exchanger 103, an expansion valve 104, and a heat source side heat exchanger 105 The heat pump circuit 107 in which the refrigerant flow path 105a is connected in an annular shape by the refrigerant pipe 106, the evaporation temperature sensor 108 for detecting the temperature of the refrigerant on the heat source side heat exchanger 105 side, and the antifreeze liquid flow path 105b of the heat source side heat exchanger 105 A ground heat circulation circuit 111 in which a geothermal heat exchanger 109 installed in the ground is connected in an annular shape by an antifreeze pipe 110, a geothermal circulation pump 112 that circulates the antifreeze liquid in the ground heat circulation circuit 111, A load-side circulation circuit 115 in which a circulating fluid passage 103b of the load-side heat exchanger 103 and a load terminal 113 such as a floor heating panel are connected in an annular shape by a circulating fluid pipe 114; A load-side circulation pump 116 that circulates the circulating fluid in the load-side circulation circuit 115; a load temperature sensor 117 that detects the temperature of the circulating fluid that flows into the circulating fluid flow path 103b of the load-side heat exchanger 103; And the control means 118 drives the compressor 102, the underground heat circulation pump 112, and the load side circulation pump 116 so that the heat source side heat exchanger 105 functions as an evaporator and condenses the load side heat exchanger 103. The control means 118 is set with the temperature of the circulating fluid detected by the load temperature sensor 117 during the heating operation. The frequency of the compressor 102 is controlled so as to reach the target temperature. (For example, refer to Patent Document 1.)

JP 2012-167902 A

  By the way, in this conventional heat pump device, as shown in FIG. 7, two heat source side heat exchangers 105 are connected in parallel to the underground heat exchanger 109, and the heating pump unit 101 on the upper stage in the figure is connected to the heating unit. When the operation is performed and heating operation is not performed on the side of the heat pump unit 101 in the lower part of the figure (here, for the sake of simplicity, the reference numerals of other components on the lower part are omitted), the upper part of the figure In the heat pump unit 101, as described above, the control means 118 controls the frequency of the compressor 102 so that the temperature of the circulating fluid detected by the load temperature sensor 117 becomes the set target temperature, and the heat pump circuit 107. The circulation flow rate of the refrigerant circulating in the tank is controlled.

  Here, in FIG. 7, when the heating operation is started on the lower heat pump unit 101 side in the drawing while the heating operation is performed on the upper heat pump unit 101 side in the drawing, the upper heat pump unit 101 in the drawing is started. Since the circulation flow rate of the underground heat circulation circuit 111 on the side is deprived to the heat pump unit 101 side in the lower part of the figure, the circulation flow rate of the underground heat circulation circuit 111 on the upper side of the figure in the figure is insufficient. Then, the amount of heat exchange in the heat source side heat exchanger 105 decreases, and the temperature of the refrigerant on the heat source side heat exchanger 105 side detected by the evaporation temperature sensor 108 rapidly decreases.

  At this time, the temperature of the refrigerant sucked into the compressor 102 also decreases due to a decrease in the amount of heat exchange in the heat source side heat exchanger 105. Therefore, the temperature of the refrigerant discharged from the compressor 102 also decreases, and the load side heat exchanger The amount of heat exchange on the 103 side also decreases, and as a result, the temperature of the circulating fluid supplied to the load terminal 113 also decreases, and the circulating fluid flow path 103b of the load side heat exchanger 103 detected by the load temperature sensor 117 enters. The temperature of the circulating fluid that flows in also decreases.

  When the control means 118 detects a decrease in temperature detected by the load temperature sensor 117, the control means 118 increases the frequency of the compressor 102 to increase the circulation flow rate of the refrigerant circulating in the heat pump circuit 107, and the load-side heat exchanger 103. If the heat exchange amount in the engine is increased to increase the temperature of the circulating fluid detected by the load temperature sensor 117, the frequency of the compressor 102 is increased to increase the circulation flow rate of the refrigerant circulating in the heat pump circuit 107. In the heat source side heat exchanger 105, the flow rate of the refrigerant flowing through the refrigerant flow path 105a of the heat source side heat exchanger 105 is increased as compared with the circulation flow rate of the antifreeze liquid flowing through the antifreeze flow path 105b of the heat source side heat exchanger 105. As a result, the amount of heat exchange in the heat source side heat exchanger 105 further decreases, and the temperature of the refrigerant on the heat source side heat exchanger 105 side further decreases. And if the temperature of the refrigerant | coolant by the side of the heat source side heat exchanger 105 is less than -15 degreeC, for example, depending on the kind of heat exchanger, the water | moisture content in the antifreeze liquid distribute | circulated by the antifreeze liquid flow path 105b side of the heat source side heat exchanger 105 As the ice begins to freeze and ice gradually builds up on the inner wall of the antifreeze liquid flow path 105b, the antifreeze liquid flow path 105b is closed, and the circulation flow rate of the antifreeze liquid circulating in the underground heat circulation circuit 111 decreases and heat source side heat exchange is performed. Since the amount of heat exchange in the heat exchanger 105 becomes insufficient, the temperature of the refrigerant on the heat source side heat exchanger 105 side further decreases. Then, the temperature of the refrigerant sucked into the compressor 102 is decreased, the temperature of the refrigerant discharged from the compressor 102 is decreased, the temperature of the circulating fluid supplied to the load terminal 113 is decreased, and the load side detected by the load temperature sensor 117 is detected. The temperature of the circulating fluid flowing into the circulating fluid flow path 103b of the heat exchanger 103 is lowered, and control is performed to further increase the frequency of the compressor 102, and the temperature of the refrigerant in the heat source side heat exchanger 105 is further lowered. As a result, ice grows in the antifreeze liquid channel 105b, and the heat source side heat exchanger 105 may be damaged.

In order to solve the above-mentioned problems, the present invention is particularly configured in the first aspect , which includes a first compressor, a refrigerant flow path of a first load side heat exchanger, a first expansion valve, and a first heat source side heat. A first heat pump circuit in which a refrigerant flow path of the exchanger is annularly connected by a first refrigerant pipe, an evaporating temperature detecting means for detecting a temperature of the refrigerant on the first heat source side heat exchanger side, a second compressor, a refrigerant flow path of the second load-side heat exchanger, a second expansion valve, a second heat pump circuit connected to the annular between the refrigerant flow path of the second heat source side heat exchanger in the second refrigerant pipe, wherein the 1 heat source side heat exchanger or heat medium circulation type heat source part for heating the refrigerant of the second heat source side heat exchanger, and the first heat source side heat exchanger and the second heat source with respect to the heat source of the heat source part connecting the side heat exchangers in parallel, between the antifreeze flow path with the heat source of the heat source unit the first heat source side heat exchanger first antifreeze pipe The formed by annularly connecting a first heat source-side circulation circuit is formed by connecting in a ring, and between the antifreeze flow path of the heat source and the second heat source-side heat exchanger of the heat source unit in the second antifreeze pipe 2 heat source side circulation circuit, first heat source side circulation pump for circulating antifreeze liquid in the first heat source side circulation circuit, second heat source side circulation pump for circulating antifreeze liquid in the second heat source side circulation circuit, and load terminal a load-side circulation circuit connected annularly circulating fluid piping between the circulating fluid flow path of the first load-side heat exchanger, and a load-side circulation pump for circulating the circulating fluid to the load-side circulation circuit, the first A load temperature detecting means for detecting the temperature of the circulating fluid flowing into the circulating fluid flow path of the one load side heat exchanger, and a control means for controlling the operation thereof, and driving the first heat source side circulating pump; evaporator the first heat source side heat exchanger to circulate the antifreeze And by function, into the load-side heating operation by function of heating the load side of the circulating pump is driven to circulate the circulation liquid of the first load-side heat exchanger as a condenser, said control means, In the heat pump device that controls the frequency or the rotation speed of the first compressor so that the temperature detected by the load temperature detecting means becomes a set target heating temperature, the second heat source side circulation is performed during the heating operation. A heating operation is started in which the pump is driven to circulate the antifreeze liquid so that the second heat source side heat exchanger functions as an evaporator, and the second load side heat exchanger functions as a condenser, and the first heat source When the circulating flow rate of the antifreeze circulating in the side circulation circuit decreases and the temperature of the refrigerant detected by the evaporating temperature detecting means decreases, the control means detects the refrigerant detected by the evaporating temperature detecting means. temperature The upper limit value of the frequency or the rotational speed of the first compressor is set accordingly.

According to a second aspect of the present invention, the control means lowers the upper limit value of the frequency or the rotational speed of the first compressor as the temperature of the refrigerant detected by the evaporation temperature detecting means decreases.

According to claim 1 of the present invention, during said heating operation, the control means, the first compressor such that the temperature detected by the load temperature detecting means becomes a set target heating temperature frequency or the number of revolutions In the heat pump device to be controlled, during the heating operation, the second heat source side circulation pump is driven to circulate the antifreeze liquid so that the second heat source side heat exchanger functions as an evaporator, and the second load side heat When the heating operation for causing the exchanger to function as a condenser is started, the circulating flow rate of the antifreeze liquid circulating in the first heat source side circulation circuit is decreased, and the temperature of the refrigerant detected by the evaporation temperature detecting means is lowered the control means, in accordance with the temperature of the refrigerant detected by the evaporation temperature detection means, by the upper limit of the frequency or rotational speed of the compressor and to set, in the heating operation, in particular, the second heat pump Circuit side Also, the heating operation is started, the second heat source side circulation pump is driven, the antifreeze liquid is circulated also in the second heat source side circulation circuit, and the circulation flow rate of the antifreeze liquid circulating in the first heat source side circulation circuit decreases. Accordingly, the amount of heat exchange in the first heat source side heat exchanger decreases, and the refrigerant temperature detected by the evaporating temperature detecting means is in the antifreeze liquid flowing through the antifreeze liquid flow path of the first heat source side heat exchanger. By setting the upper limit value of the frequency or rotation speed of the first compressor when the temperature drops to a temperature at which moisture may be frozen, the circulation flow rate of the refrigerant circulating in the first heat pump circuit is adjusted, and the first heat source side Since the amount of heat exchange from the refrigerant to the antifreeze liquid in the heat exchanger can be adjusted, the freezing of water in the antifreeze liquid flowing through the antifreeze liquid passage of the first heat source side heat exchanger is prevented, and the heat source side heat exchanger is damaged. Can be prevented in advance

According to claim 2, the control means reduces the upper limit value of the frequency or the rotational speed of the first compressor as the refrigerant temperature detected by the evaporation temperature detecting means decreases . 1 The upper limit of the circulation flow rate of the refrigerant circulating in the heat pump circuit is suppressed to lower the refrigerant circulation flow rate, the amount of heat exchange from the refrigerant to the antifreeze liquid in the first heat source side heat exchanger is suppressed, and the first heat source side heat exchanger It is possible to prevent freezing of water in the antifreeze liquid flowing through the antifreeze liquid flow path and to prevent the first heat source side heat exchanger from being damaged.

BRIEF DESCRIPTION OF THE DRAWINGS The schematic block diagram of the heat pump apparatus of one Embodiment of this invention. The flowchart which shows the operation | movement at the time of the heating operation of the same embodiment. The figure which shows the relationship between the refrigerant | coolant temperature of the gas-liquid mixing state by the side of the heat source side heat exchanger of the same embodiment, and the upper limit of the frequency of a compressor. The time chart which shows the operation | movement at the time of the heating operation of the same embodiment. The time chart which shows the operation | movement at the time of the heating operation of the conventional heat pump apparatus. The schematic block diagram of the conventional heat pump apparatus. The schematic block diagram at the time of connecting two heat source side heat exchangers of the conventional heat pump apparatus in parallel with respect to the underground heat exchanger.

Next, a heat pump device according to an embodiment of the present invention will be described with reference to FIG.
As shown in the figure, the heat pump device of this embodiment is roughly divided into heat pump units 1A and 1B as outdoor units, a heat medium circulation type heat source heat exchange unit 2 as a heat source unit, and load heat exchange units 3A and 3B. It is comprised from.

  The heat pump unit 1A circulates a first compressor 4 having a variable operating frequency or operating speed and a high-temperature and high-pressure refrigerant discharged from the first compressor 4 for compressing the refrigerant. A first load-side heat exchanger 5 as a first condenser that performs heat exchange with the heat medium on the load side of 3A, and a first decompression unit that decompresses the refrigerant flowing out of the first load-side heat exchanger 5 The first heat source side heat exchanger as a first evaporator that performs heat exchange between the first expansion valve 6 and the low-temperature and low-pressure refrigerant decompressed by the first expansion valve 6 and the heat medium on the heat source side of the heat source heat exchange unit 2 7, and the first compressor 4, the refrigerant flow path 5 a of the first load side heat exchanger 5, the first expansion valve 6, and the refrigerant flow path 7 a of the first heat source side heat exchanger 7 are connected to the first refrigerant pipe. In FIG. 8, the first heat pump circuit 9 is formed in a ring shape. In addition, as a refrigerant | coolant which circulates through the 1st heat pump circuit 9, arbitrary refrigerant | coolants, such as a carbon dioxide refrigerant | coolant and a HFC refrigerant | coolant, can be used. Further, 10 is a first discharge temperature sensor as a first discharge temperature detecting means for detecting the temperature of the refrigerant discharged from the first compressor 4, and 11 is the temperature of the refrigerant on the first heat source side heat exchanger 7 side, that is, 2 is a first evaporation temperature sensor as first evaporation temperature detection means for detecting the temperature of the refrigerant in the gas-liquid mixed state from the outlet of the first expansion valve 6 to the outlet of the first heat source side heat exchanger 7.

  The first heat source side heat exchanger 7 is constituted by a plate heat exchanger, and the plate heat exchanger is formed by stacking a plurality of heat transfer plates, and a refrigerant flow path 7a for circulating the refrigerant and an antifreeze liquid path for circulating the antifreeze liquid. 7b are alternately formed with each heat transfer plate as a boundary.

  The heat source heat exchanging unit 2 serves as a heat source for heating the refrigerant flowing through the antifreeze liquid flow path 7b through which the antifreeze liquid flows in the first heat source side heat exchanger 7 and the refrigerant flow path 7a of the first heat source side heat exchanger 7. The underground heat exchanger 12 installed in the ground is connected to a first heat transfer pipe 13 as a first antifreeze liquid pipe, an outgoing header -14, an underground outgoing pipe 15, an underground return pipe 16, and a return header 17 A first ground heat circulation circuit 19 as a first heat source side circulation circuit connected in a ring shape by the first heat exchange return pipe 18, and an antifreeze liquid in which ethylene glycol, propylene glycol or the like is added to the first ground heat circulation circuit 19 And a first underground heat circulation pump 20 as a first heat source side circulation pump with variable rotation speed.

  Here, in the heat source heat exchanging unit 2, when the heating operation described later is performed on the heat pump unit 1A side, the underground heat exchanger 12 collects the ground heat from the ground, and the antifreeze liquid with the heat is the first. 1 The ground heat circulation pump 20 supplies the antifreeze liquid flow path 7b of the first heat source side heat exchanger 7. And in the 1st heat source side heat exchanger 7, the refrigerant | coolant which distribute | circulates the refrigerant | coolant flow path 7a and the antifreeze liquid which distribute | circulates the antifreeze liquid flow path 7b flow oppositely, heat exchange is performed, and the underground heat exchanger 12 is passed. The ground heat collected in this manner is pumped up to the refrigerant side of the heat pump unit 1A to heat the refrigerant, and the first heat source side heat exchanger 7 functions as an evaporator.

  The load heat exchanging unit 3A firstly connects the circulating fluid passage 5b for circulating the circulating fluid in the first load-side heat exchanger 5 and the first load terminal 21 such as a floor heating panel for heating the air-conditioned space. A first load-side circulation circuit 23 connected in a ring shape with a circulating fluid pipe 22, a first load-side circulation pump 24 that circulates a circulating fluid such as water or antifreeze into the first load-side circulation circuit 23, and a first load-side circulation A first return temperature sensor as a first load temperature detecting means provided in the circuit 23 for detecting the temperature of the circulating fluid flowing out from the first load terminal 21 and flowing into the circulating fluid flow path 5b of the first load side heat exchanger 5 25.

  A first remote controller (not shown) is installed in the air-conditioned space heated by the first load terminal 21, and heating of the air-conditioned space where the first load terminal 21 is provided by the first remote controller. When instructed, driving of the first compressor 4, the first underground heat circulation pump 20, and the first load side circulation pump 24 is started, and the first heat source side heat exchanger 7 functions as an evaporator, A heating operation is performed in which the first load-side heat exchanger 5 functions as a condenser to heat the load side. During the heating operation, in the first load-side heat exchanger 5, the refrigerant flowing through the refrigerant flow path 5a and the circulating liquid flowing through the circulating liquid flow path 5b flow oppositely to perform heat exchange. The circulating fluid heated in the load-side heat exchanger 5 is sent to the first load terminal 21 and heats the air-conditioned space that is instructed by the first remote controller.

  26 receives the input from the first discharge temperature sensor 10, the first evaporation temperature sensor 11, the first return temperature sensor 25 and the signal from the first remote controller, and receives the first compressor 4, the first expansion valve 6, and the first. The first control means includes a microcomputer that controls the operation of each actuator of the geothermal circulation pump 20 and the first load-side circulation pump 24.

  The first control means 26 sets the target heating temperature based on the set temperature of the first load terminal 21 set by the first remote controller during the heating operation, and the temperature of the circulating fluid detected by the first return temperature sensor 25. However, if the frequency of the 1st compressor 4 is controlled so that it may become the set target heating temperature, for example, the temperature of the circulating fluid which the 1st return temperature sensor 25 detects will fall from the set target heating temperature. The frequency of the first compressor 4 is controlled to increase.

  Further, the first control means 26 sets a target discharge temperature of the refrigerant discharged from the first compressor 4 based on the set temperature of the first load terminal 21 set by the first remote controller during the heating operation, The opening degree of the first expansion valve 6 is controlled so that the refrigerant temperature detected by the first discharge temperature sensor 10 becomes the set target discharge temperature. For example, the refrigerant temperature detected by the first discharge temperature sensor 10 is controlled. When the temperature drops below the target discharge temperature, the opening degree is controlled in the closing direction.

  In addition, during the heating operation, the first control means 26 is a refrigerant in a gas-liquid mixed state from the outlet of the first expansion valve 6 detected by the first evaporation temperature sensor 11 to the outlet of the first heat source side heat exchanger 7. The number of revolutions of the first underground heat circulation pump 20 is controlled so that the temperature of the refrigerant reaches the set target evaporation temperature. For example, the refrigerant temperature detected by the first evaporation temperature sensor 11 is set to the set target evaporation temperature. If it falls below, it will control to increase the rotation speed of the 1st underground heat circulation pump 20.

  Further, the heat pump unit 1B circulates the second compressor 27 having a variable operating frequency or operating speed and compressing the refrigerant, and the high-temperature and high-pressure refrigerant discharged from the second compressor 27. A second load-side heat exchanger 28 serving as a second condenser that performs heat exchange with the load-side heat medium of the exchange unit 3B, and second decompression means for decompressing the refrigerant flowing out of the second load-side heat exchanger 28 The second expansion valve 29 as a second heat source side heat as a second evaporator that performs heat exchange between the low-temperature and low-pressure refrigerant decompressed by the second expansion valve 29 and the heat medium on the heat source side of the heat source heat exchanging unit 2 The second compressor 27, the refrigerant flow path 28a of the second load side heat exchanger 28, the second expansion valve 29, and the refrigerant flow path 30a of the second heat source side heat exchanger 30. A second heat pump circuit 32 is formed by connecting the refrigerant pipe 31 in a ring shape. It is those who are. In addition, as a refrigerant | coolant which circulates through the 2nd heat pump circuit 32, arbitrary refrigerant | coolants, such as a carbon dioxide refrigerant | coolant and a HFC refrigerant | coolant, can be used. Reference numeral 33 denotes a second discharge temperature sensor as second discharge temperature detecting means for detecting the temperature of the refrigerant discharged from the second compressor 27, and 34 denotes the temperature of the refrigerant on the second heat source side heat exchanger 30 side, That is, it is a second evaporation temperature sensor as a second evaporation temperature detecting means for detecting the temperature of the refrigerant in the gas-liquid mixed state from the outlet of the second expansion valve 29 to the outlet of the second heat source side heat exchanger 30.

  The second heat source side heat exchanger 30 is composed of a plate heat exchanger, and the plate heat exchanger is formed by stacking a plurality of heat transfer plates, and a refrigerant flow path 30a for circulating a refrigerant and an antifreeze liquid path for circulating an antifreeze liquid. 30b are alternately formed with each heat transfer plate as a boundary.

  The heat source heat exchanging unit 2 heats the refrigerant flowing through the antifreeze liquid flow path 30b through which the antifreeze liquid flows in the second heat source side heat exchanger 30 and the refrigerant flow path 30a of the second heat source side heat exchanger 30. The underground heat exchanger 12 installed in the ground as a heat source is connected to the second heat exchange pipe 35 as the second antifreeze pipe, the forward header 14, the underground forward pipe 15, the underground return pipe 16, and the return header 17 A second ground heat circulation circuit 37 as a second heat source side circulation circuit connected in a ring shape by the second heat exchange return pipe 36, and an antifreeze liquid obtained by adding ethylene glycol, propylene glycol or the like to the second ground heat circulation circuit 37 And a second underground heat circulation pump 38 as a second heat source side circulation pump with variable rotation speed, and the heat source heat exchanging unit 2 includes a first heat source side heat exchanger of the heat pump unit 1A. 7 and heat pump Tsu and second heat source side heat exchanger 30 of the bets 1B is one that is connected in parallel with the underground heat exchanger 12.

  Here, in the heat source heat exchanging unit 2, when the heating operation described later is performed on the heat pump unit 1B side, the underground heat exchanger 12 collects the ground heat from the ground, and the antifreeze liquid with the heat is the first. 2 The ground heat circulation pump 38 supplies the antifreeze liquid flow path 30b of the second heat source side heat exchanger 30. And in the 2nd heat source side heat exchanger 30, the refrigerant | coolant which distribute | circulates the refrigerant | coolant flow path 30a and the antifreeze liquid which distribute | circulates the antifreeze liquid flow path 30b flow oppositely, heat exchange is performed, and the underground heat exchanger 12 is passed. The ground heat collected in this manner is pumped up to the refrigerant on the heat pump unit 1B side, and the refrigerant is heated, and the second heat source side heat exchanger 30 functions as an evaporator.

  The load heat exchanging unit 3B includes a circulating fluid passage 28b for circulating the circulating fluid in the second load side heat exchanger 28 and a second load terminal 39 such as a floor heating panel for heating the air-conditioned space. A second load-side circulation circuit 41 connected in a ring shape with a circulating fluid pipe 40, a second load-side circulation pump 42 for circulating a circulating fluid such as water or antifreeze into the second load-side circulation circuit 41, and a second load-side circulation A second return temperature sensor as a second load temperature detecting means provided in the circuit 41 for detecting the temperature of the circulating fluid flowing out from the second load terminal 39 and flowing into the circulating fluid flow path 28b of the second load side heat exchanger 28. 43.

  A second remote controller (not shown) is installed in the air-conditioned space heated by the second load terminal 39, and heating of the air-conditioned space in which the second load terminal 39 is provided by the second remote controller. When instructed, driving of the second compressor 27, the second underground heat circulation pump 38, and the second load side circulation pump 42 is started, and the second heat source side heat exchanger 30 functions as an evaporator, Heating operation for heating the load side by causing the second load side heat exchanger 28 to function as a condenser is performed. During the heating operation, in the second load side heat exchanger 28, the refrigerant flowing through the refrigerant flow path 28a and the circulating liquid flowing through the circulating liquid flow path 28b flow oppositely to perform heat exchange. The circulating fluid heated by the load-side heat exchanger 28 is sent to the second load terminal 39 and heats the air-conditioned space that is instructed by the second remote controller.

  44 receives the input of the 2nd discharge temperature sensor 33, the 2nd evaporation temperature sensor 34, the 2nd return temperature sensor 43, and the signal from the 2nd remote control, the 2nd compressor 27, the 2nd expansion valve 29, the 2nd ground The second control means includes a microcomputer that controls the operation of each actuator of the intermediate heat circulation pump 38 and the second load side circulation pump 42.

  The second control means 44 sets the target heating temperature based on the set temperature of the second load terminal 39 set by the second remote controller during the heating operation, and the temperature of the circulating fluid detected by the second return temperature sensor 43. However, if the frequency of the 2nd compressor 27 is controlled so that it may become the set target heating temperature, for example, the temperature of the circulating fluid which the 2nd return temperature sensor 43 detects will fall from the set target heating temperature. The control is performed to increase the frequency of the second compressor 27.

  Further, the second control means 44 sets a target discharge temperature of the refrigerant discharged from the second compressor 27 based on the set temperature of the second load terminal 39 set by the second remote controller during the heating operation, The opening of the second expansion valve 29 is controlled to open and close so that the temperature of the refrigerant detected by the second discharge temperature sensor 33 becomes the set target discharge temperature. For example, the temperature of the refrigerant detected by the second discharge temperature sensor 33 When the temperature drops below the target discharge temperature, the opening degree is controlled in the closing direction.

  In addition, during the heating operation, the second control means 44 is a refrigerant in a gas-liquid mixed state from the outlet of the second expansion valve 29 detected by the second evaporation temperature sensor 34 to the outlet of the second heat source side heat exchanger 30. The number of rotations of the second underground heat circulation pump 38 is controlled so that the temperature of the second underground heat circulation pump 38 becomes the set target evaporation temperature. For example, the refrigerant temperature detected by the second evaporation temperature sensor 34 is set to the set target evaporation temperature. If it falls below, it controls so that the rotation speed of the 2nd underground heat circulation pump 38 may be increased.

  Next, characteristic operations during the heating operation of the heat pump apparatus according to the embodiment shown in FIG. 1 will be described based on the flowchart shown in FIG. 2. Here, the case where the heat pump unit 1 </ b> A is performing the heating operation will be described as an example. Will be described.

  When an instruction to heat the air-conditioned space is given by the first load terminal 21 by the first remote controller (not shown), the first control means 26 includes the first compressor 4 and the first underground heat circulation pump 20. Then, the driving of the first load side circulation pump 24 is started, and the heating operation is started. When the heating operation is started, the first load-side heat exchanger 5 exchanges heat between the heating circulation liquid circulated by the first load-side circulation pump 24 and the high-temperature and high-pressure refrigerant discharged from the first compressor 4. The heated heating circulating fluid is supplied to the first load terminal 21 to heat the air-conditioned space, and in the first heat source side heat exchanger 7, the ground heat exchanger is circulated by the first ground heat circulation pump 20. The antifreeze obtained by collecting the geothermal heat via 12 and the low-temperature and low-pressure refrigerant discharged from the first expansion valve 6 are subjected to heat exchange, and the refrigerant is heated and evaporated by the underground heat.

  During the heating operation, the first control means 26 monitors the refrigerant temperature detected by the first evaporation temperature sensor 11 (step S1), and according to the temperature, the first compressor 4 of the first compressor 4 is based on a setting method to be described later. The upper limit value of the frequency is set (step S2), and the first control means 26 controls the frequency of the first compressor 4 based on the setting.

  Here, the setting method for setting the upper limit value of the frequency of the first compressor 4 in step S2 will be described. As shown in FIG. 3, the outlet of the first expansion valve 6 detected by the first evaporation temperature sensor 11 is described. A plurality of zones z1 to z3 corresponding to the refrigerant temperature in the gas-liquid mixed state from the first heat source side heat exchanger 7 to the outlet of the first heat source side heat exchanger 7 are provided, and the upper limit value of the frequency of the first compressor 4 is set in each of the zones z1 to z3. For example, in the zone z1 that is an area above the thick line α, the upper limit value of the frequency of the first compressor 4 is 90 Hz, and in the zone z2 that is the area between the thick line α and the thick line β, the first compression is performed. When the upper limit value of the frequency of the machine 4 is 60 Hz and the upper limit value of the frequency of the first compressor 4 is set to 35 Hz in the zone z3 which is an area below the thick line β, the first evaporating temperature sensor 11 is used during the heating operation. When the detected temperature is -5 ° C When the upper limit value of the frequency of the first compressor 4 is set to 90 Hz and the temperature detected by the first evaporation temperature sensor 11 is −10.5 ° C., the upper limit value of the frequency of the first compressor 4 is set to 60 Hz. When the temperature detected by the first evaporation temperature sensor 11 is −14 ° C., the upper limit value of the frequency of the first compressor 4 is set to 35 Hz.

  Further, the refrigerant temperature detected by the first evaporation temperature sensor 11 exceeds the thick line α, which is the boundary line between the zone z1 and the zone z5, from the refrigerant temperature included in the zone z1, as indicated by the downward arrow d1 shown in FIG. When the refrigerant temperature falls to the refrigerant temperature included in the zone z2, that is, the refrigerant temperature detected by the first evaporation temperature sensor 11 exceeds -10 ° C, which is the boundary between the zone z1 and the zone z2, from -5 ° C to -10. When the temperature falls to 5 ° C., the upper limit value of the frequency of the first compressor 4 is changed from 90 Hz to 60 Hz, and is included in the zone z2 as indicated by the downward arrow d2 shown in FIG. When the refrigerant temperature falls from the refrigerant line temperature exceeding the thick line β that is the boundary line between the zone z2 and the zone z3 to the refrigerant temperature contained in the zone z3, that is, the refrigerant temperature detected by the first evaporation temperature sensor 11 is −10. When the temperature falls from −5 ° C. to −14 ° C. exceeding −13 ° C. which is the boundary between the zone z2 and the zone z3, the upper limit value of the frequency of the first compressor 4 is changed from 60 Hz to 35 Hz.

  On the contrary, as shown by the upward arrow u1 shown in FIG. 3, when the refrigerant temperature rises from the refrigerant temperature contained in the zone z3 to the refrigerant temperature contained in the zone z2 beyond the thick line β that is the boundary line between the zone z3 and the zone z2. That is, when the refrigerant temperature detected by the first evaporating temperature sensor 11 rises from −14 ° C. to −10.5 ° C. beyond −11 ° C., which is the boundary between the zones z 3 and z 2, the first compressor 4 The upper limit value of the frequency is changed from 35 Hz to 60 Hz, and is a boundary line between the zone z2 and the zone z1 from the refrigerant temperature contained in the zone z2, as indicated by the upward arrow u2 shown in FIG. When the temperature rises to the refrigerant temperature included in the zone z1 beyond the thick line α, that is, the refrigerant temperature detected by the first evaporation temperature sensor 11 is a boundary between the zone z2 and the zone z1 from −10.5 ° C. − When the temperature exceeds 8 ° C. and rises to −5 ° C., the upper limit value of the frequency of the first compressor 4 is changed from 60 Hz to 90 Hz.

  The first control means 26 includes the refrigerant temperature in the gas-liquid mixed state from the outlet of the first expansion valve 6 to the outlet of the first heat source side heat exchanger 7 shown in FIG. The first control means 26 is based on the information during the heating operation, and the first heat source side heat exchanger 7 side detected by the first evaporation temperature sensor 11 is stored in advance. The upper limit of the frequency of the first compressor 4 is set according to the temperature of the refrigerant. Further, when the refrigerant temperature detected by the first evaporation temperature sensor 11 is the refrigerant temperature included in the zone z3 during the heating operation, the moisture in the antifreeze liquid flowing through the antifreeze liquid flow path 7b of the first heat source side heat exchanger 7 is obtained. Since the upper limit of the frequency of the first compressor 4 is set to 35 Hz, the first control means 26 fully opens the opening of the first expansion valve 6 and the refrigerant flows into the first expansion valve 6. In the antifreeze liquid flowing through the refrigerant flow path 7a of the first heat source side heat exchanger 7 and flowing through the antifreeze liquid flow path 7b of the first heat source side heat exchanger 7 by heat exchange between the refrigerant and the antifreeze liquid. The water in the antifreeze liquid flowing through the antifreeze liquid flow path 7b of the first heat source side heat exchanger 7 is released.

  Next, the operation of the heating operation in the present embodiment will be described using the time chart of FIG. 4 with the control of FIG. 2 described above. Here, the heat pump unit 1A is performing the heating operation. The case where the heating operation is started in the heat pump unit 1B will be described. Various parameters such as the heating output and the detected refrigerant temperature in the time chart of FIG. 4 are parameters on the heat pump unit 1A side. FIG. 5 shows the conventional heat pump apparatus shown in FIG. 7. While the upper heat pump unit 101 in the conventional heat pump apparatus is performing the heating operation, the lower heat pump unit in the conventional heat pump apparatus in the figure. 101 is a time chart when the heating operation is started at 101, and is used for comparison with the time chart of FIG. In the time chart of FIG. 4, the time t0 is not the time when the heating operation is started, but is an arbitrary time after the heating operation is performed and stabilized to some extent, and the time t0 to the time t4 are time t0 of the time chart of FIG. ~ Represents the same timing as time t4. Furthermore, in the time chart of FIG. 5, it is assumed that the upper limit value of the compressor frequency is set to a fixed upper limit value (90 Hz).

  First, at the time t0 after the heating operation is performed to some extent in the heat pump unit 1A in FIG. 4 and stabilized, the first evaporating temperature sensor 11 causes the first heat source side heat exchanger 7 to exit from the outlet of the first expansion valve 6. The temperature of the refrigerant in the gas-liquid mixed state up to the outlet is detected (step S1), and the first control means 26 is shown in FIG. 3 because the refrigerant temperature detected by the first evaporation temperature sensor 11 is 2 ° C. From the relationship between the refrigerant temperature in the gas-liquid mixed state from the outlet of the first expansion valve 6 to the outlet of the first heat source side heat exchanger 7 and the upper limit value of the frequency of the first compressor 4, The upper limit value of the frequency is set to 90 Hz (step S2). From time t0 to time t1, since the refrigerant temperature detected by the first evaporation temperature sensor 11 is 2 ° C., the upper limit value of the frequency of the first compressor 4 is set to 90 Hz during this period.

  Here, at the time t1, when the heating operation is started in the heat pump unit 1B, the second underground heat circulation pump 38 is driven, and the antifreeze liquid is also circulated in the second underground heat circulation circuit 37. From the time t1, the circulation flow rate of the antifreeze circulating in the first underground heat circulation circuit 19 decreases, and accordingly, the amount of heat exchange in the first heat source side heat exchanger 7 decreases. The refrigerant temperature detected by the evaporation temperature sensor 11 also decreases. During the period from time t1 to time t2, the first control means 26 determines that the refrigerant temperature detected by the first evaporation temperature sensor 11 has decreased from the set target evaporation temperature, here 2 ° C., and the target evaporation temperature. Control is performed to increase the rotational speed of the first underground heat circulation pump 20 so as to be 2 ° C. Further, during the period from time t1 to time t2, the temperature of the circulating fluid flowing into the circulating fluid flow path 5b of the first load-side heat exchanger 5 due to the decrease in the refrigerant temperature on the first heat source side heat exchanger 7 side. When the decrease starts, the first control means 26 determines that the temperature of the circulating fluid detected by the first return temperature sensor 25 has decreased from the set target heating temperature, here 40 ° C. Control to increase the frequency of the first compressor 4 so as to be 40 ° C. is performed.

  Subsequently, at time t2, the first control means 26 confirms that the refrigerant temperature detected by the first evaporation temperature sensor 11 has dropped below -10 ° C., which is the boundary between the zone z1 and the zone z2 shown in FIG. When detected, the upper limit value of the frequency of the first compressor 4 is changed from 90 Hz to 60 Hz. Along with the setting change of the upper limit value of the frequency of the first compressor 4, the first control means 26 performs control to decrease the frequency of the first compressor 4 from time t 2, thereby causing the first heat pump circuit 9 to be changed. Reduce the circulation flow rate of the circulating refrigerant. If it does so, the fall degree of the refrigerant | coolant temperature which the 1st evaporation temperature sensor 11 detects will become small, and the fall of a refrigerant | coolant temperature will converge. Then, during the period from time t2 to time t3, the first control means 26 determines the rotation speed of the first underground heat circulation pump 20 so that the temperature detected by the first evaporation temperature sensor 11 becomes the target evaporation temperature (2 ° C.). However, as the rotation speed of the first underground heat circulation pump 20 increases, the circulation flow rate of the antifreeze circulating through the first underground heat circulation circuit 19 is reversed from decrease to increase, Since the heat exchange amount in the first heat source side heat exchanger 7 increases, the refrigerant temperature detected by the first evaporation temperature sensor 11 starts to rise. Further, during this period, the refrigerant temperature detected by the first evaporation temperature sensor 11 is the refrigerant temperature included in the zone z2 shown in FIG. 3, and therefore the upper limit value of the frequency of the first compressor 4 is set to 60 Hz.

  At time t3, the first control means 26 detects that the refrigerant temperature detected by the first evaporation temperature sensor 11 has risen beyond −8 ° C., which is the boundary between the zone z2 and the zone z1 shown in FIG. Then, the upper limit value of the frequency of the first compressor 4 is changed from 60 Hz to 90 Hz. Along with the setting change of the upper limit value of the frequency of the first compressor 4, from time t 3, the first control means 26 sets the target heating temperature (40) at which the temperature of the circulating fluid detected by the first return temperature sensor 25 is set. When the temperature of the circulating fluid detected by the first return temperature sensor 25 reaches the set target heating temperature, the target heating temperature is reached. The frequency of the first compressor 4 at the time (75 Hz) is maintained. Further, during the period from time t3 to time t4, the temperature detected by the first evaporation temperature sensor 11 gradually increases and reaches 2 ° C. which is the target evaporation temperature. Maintaining the rotation speed (4500 rpm) of the first underground heat circulation pump 20 when the target evaporation temperature is reached so that the temperature detected by the sensor 11 maintains the target evaporation temperature (2 ° C.), The heating operation is performed until an instruction to stop the heating operation is issued from the first remote controller.

  Although not shown in the time chart of FIG. 4, the refrigerant temperature detected by the first evaporation temperature sensor 11 during the heating operation is a predetermined value in the minus region as the boundary between the zone z2 and the zone z3 shown in FIG. When it is detected that the temperature has dropped below -13 ° C, or when the temperature has dropped below -13 ° C and a predetermined time has passed, the first control means 26 The upper limit value of the frequency of the first compressor 4 is set to 35 Hz, the opening degree of the first expansion valve 6 is fully opened, and the refrigerant flowing out of the refrigerant flow path 5a of the first load side heat exchanger 5 is the first. The refrigerant is passed through the expansion valve 6 without being depressurized, and directly flows into the refrigerant flow path 7a of the first heat source side heat exchanger 7, and the antifreeze liquid flow of the first heat source side heat exchanger 7 is obtained by heat exchange between the warm refrigerant and the antifreeze liquid. Prevent freezing of water in antifreeze flowing through path 7b , Or moisture in the antifreeze circulating the antifreeze channel 7b of the first heat source-side heat exchanger 7 is capable of thawing those frozen.

  Further, while the rotation speed of the first underground heat circulation pump 20 increases from time t1 to time t4 in the time chart of FIG. 5, the circulation of the antifreeze liquid circulating in the first underground heat circulation circuit 19 is performed. Although the flow rate decreases, the cause of the decrease in the circulating flow rate of the antifreeze liquid circulating through the first underground heat circulation circuit 19 is the second ground heat of the heat pump unit 1B in the first half of the period from time t1 to time t4. The antifreeze is circulated also in the second underground heat circulation circuit 37 by driving the circulation pump 38. In the latter half, the antifreeze cannot be circulated due to freezing in the antifreeze flow path 7b of the first heat source side heat exchanger 7. Is by becoming. And about the increase in the rotation speed of the 1st underground heat circulation pump 20, since the antifreeze liquid of the 1st underground heat circulation pump 20 vicinity is not frozen and can rotate, the 1st underground heat circulation pump 20 is rotated. 5 is controlled so that the refrigerant temperature detected by the first evaporating temperature sensor 11 is set to the target temperature. However, since the target temperature is not reached, only the rotation speed increases and the time shown in FIG. The chart is such a graph.

  In the heating operation described above, the frequency of the first compressor 4 is controlled so that the temperature of the circulating fluid detected by the first return temperature sensor 25 becomes the set target heating temperature during the heating operation. The upper limit value of the frequency of the first compressor 4 according to the temperature of the refrigerant in the gas-liquid mixed state from the outlet of the first expansion valve 6 to the outlet of the first heat source side heat exchanger 7 detected by the evaporation temperature sensor 11. Therefore, during the heating operation, the refrigerant temperature detected by the first evaporating temperature sensor 11 due to the insufficient circulation rate of the antifreeze liquid in the first underground heat circulation circuit 19 becomes the first heat source side heat. The first heat pump is set by setting an upper limit value of the frequency of the first compressor 4 when the temperature in the antifreeze liquid flowing through the antifreeze liquid flow path 7b of the exchanger 7 is lowered to a temperature in a minus range where the water may be frozen. Circulation of refrigerant circulating in circuit 9 Since the flow rate is adjusted and the amount of heat exchange from the refrigerant to the antifreeze liquid in the first heat source side heat exchanger 7 can be adjusted to be suppressed, the antifreeze liquid flowing through the antifreeze liquid flow path 7b of the first heat source side heat exchanger 7 is adjusted. It is possible to prevent freezing of moisture in the inside, prevent damage to the first heat source side heat exchanger 7 and prevent freezing of moisture in the antifreeze liquid flowing through the antifreeze liquid flow path 7b of the first heat source side heat exchanger 7. By preventing, since the heating operation is continued, no heating is not performed.

  Further, as can be seen from the comparison between the time chart of FIG. 4 and the time chart of FIG. 5, the refrigerant temperature detected by the first evaporation temperature sensor 11 is negative like time t <b> 1 to time t <b> 3 of the time chart of FIG. 4. Since the upper limit value of the frequency of the first compressor 4 is lowered as it reaches and decreases, the upper limit value of the circulation flow rate of the refrigerant circulating in the first heat pump circuit 9 is suppressed, and the refrigerant circulation flow rate is lowered. The amount of heat exchange from the refrigerant to the antifreeze liquid in the first heat source side heat exchanger 7 is suppressed, and as a result, the freezing of moisture in the antifreeze liquid flowing through the antifreeze liquid flow path 7b of the first heat source side heat exchanger 7 is prevented, and the first Damage to the heat source side heat exchanger 7 can be prevented in advance.

  In addition, this invention is not limited to said one Embodiment, In this embodiment, the upper limit of the frequency of the 1st compressor 4 is set according to the refrigerant | coolant temperature which the 1st evaporation temperature sensor 11 detects. However, the rotation speed of the first compressor 4 is changed according to the refrigerant temperature detected by the first evaporation temperature sensor 11 using the rotation speed of the first compressor 4 instead of the frequency of the first compressor 4. An upper limit value of the number may be set.

  Further, in the present embodiment, the upper limit values of the frequencies of the three first compressors 4 can be set according to the refrigerant temperature detected by the first evaporation temperature sensor 11, but it is not necessary to limit the number to three. According to the refrigerant temperature detected by the first evaporating temperature sensor 11, a necessary upper limit value of the frequency of the first compressor 4 may be prepared.

  In the present embodiment, the control of the present invention is applied to the first control means 26 of the heat pump unit 1A. However, the control of the present invention may be applied to the second control means 44 of the heat pump unit 1B. The control of the present invention may be applied to both the first control means 26 of the heat pump unit 1A and the second control means 44 of the heat pump unit 1B.

  In the present embodiment, the first heat source side heat exchanger 7 of the heat pump unit 1A and the second heat source side heat exchanger 30 of the heat pump unit 1B are connected in parallel to the underground heat exchanger 12. In the case where the heating operation is started in the heat pump unit 1B while the heat pump unit 1A is performing the heating operation, the circulation flow rate of the first underground heat circulation circuit 19 is reduced. Although the control of the present invention is applied to the case where the refrigerant temperature detected by the first evaporating temperature sensor 11 is decreased, the present invention is not limited to this, and there is no heat pump unit 1B side, and the first heat source side heat exchange of one heat pump unit 1A is performed. Even in the case where one underground heat exchanger 12 corresponds to the cooler 7, the circulation flow rate of the first underground heat circulation circuit 19 may decrease. When the first pump is installed, the first ground heat circulation circuit 19 is not completely vented, and the air moves during the heating operation, and the first ground heat circulation pump 20 generates air bites. When the circulation flow rate of the first underground heat circulation circuit 19 is reduced, or when the heat pump device is installed, stones, gravel mixed in the antifreeze pipe, seal materials used for the connection part of the antifreeze pipe, During the heating operation, the first ground heat circulation pump 20 is driven to move through the first ground heat circulation circuit 19, and a strainer (not shown) provided at an appropriate position of the first ground heat circulation circuit 19 is installed. In this case, the circulation flow rate of the first underground heat circulation circuit 19 may be reduced. In this case, the refrigerant temperature detected by the first evaporation temperature sensor 11 is reduced. Even if the control of the present invention is applied The first heat source side heat is the same as that in which the first heat source side heat exchanger 7 of the heat pump unit 1A and the second heat source side heat exchanger 30 of the heat pump unit 1B are connected in parallel to the underground heat exchanger 12. The effect of preventing the freezing of the water in the antifreeze liquid flowing through the antifreeze liquid flow path 7b of the exchanger 7 and preventing the first heat source side heat exchanger 7 from being damaged can be exhibited.

  Further, in the present embodiment, as a heat medium circulation type heat source section for heating the refrigerant flowing through the refrigerant flow path 7a of the first heat source side heat exchanger 7 or the refrigerant flow path 30a of the second heat source side heat exchanger 30, Although the heat source heat exchanging part 2 that collects heat from the ground through the underground heat exchanger 12 is adopted, as the heat source part, the first heat source side heat exchanger is circulated by circulating the water of the river, the lake, and the sea. 7 or a heat medium circulation type that heats the refrigerant flowing through the refrigerant flow path 30a of the second heat source side heat exchanger 30, and the hot water stored in the hot water storage tank can be directly used. Refrigerant that circulates through the refrigerant flow path 7a of the first heat source side heat exchanger 7 or the refrigerant flow path 30a of the second heat source side heat exchanger 30 using the water well or directly or using well water directly or indirectly It may be a heat medium circulating type that heats.

  Moreover, in one Embodiment of this invention demonstrated previously, although the heat pump apparatus which can perform only the said heating operation was shown, it is a four-way valve in the 1st heat pump circuit 9 in the heat pump unit 1A, or the 2nd heat pump circuit 32 in the heat pump unit 1B. In the heat pump apparatus that can perform both the heating operation and the cooling operation by switching the four-way valve, the first control means 26 or the second control means 44 may apply the control of the present invention during the heating operation. It is.

  In the present embodiment, the first evaporation temperature sensor 11 detects the temperature of the gas-liquid mixed refrigerant from the outlet of the first expansion valve 6 to the outlet of the first heat source side heat exchanger 7. When the first heat source side heat exchanger 7 is a plate-type or double-tube type water-refrigerant heat exchanger, the temperature of the refrigerant in the gas-liquid mixed state in the refrigerant flow path 7a of the first heat source-side heat exchanger 7 As shown in FIG. 1, the first evaporation temperature sensor 11 is provided in the first refrigerant pipe 8 from the outlet of the first expansion valve 6 to the inlet of the first heat source side heat exchanger 7 as shown in FIG. It is easy and easy to install. Similarly, it is preferable that the second evaporation temperature sensor 34 is provided in the second refrigerant pipe 31 from the outlet of the second expansion valve 29 to the inlet of the second heat source side heat exchanger 30 because it is easy to attach.

2 Heat source heat exchanger 4 First compressor 5 First load side heat exchanger 5a Refrigerant flow path of first load side heat exchanger 5b Circulating fluid flow path of first load side heat exchanger 6 First expansion valve 7 First 1 heat source side heat exchanger 7a refrigerant flow path of first heat source side heat exchanger 7b antifreeze liquid flow path of first heat source side heat exchanger 8 first refrigerant pipe 9 first heat pump circuit 11 first evaporating temperature sensor 12 underground heat Exchanger 13 First heat exchange pipe 15 Underground pipe 16 Underground return pipe 18 First heat exchange return pipe 19 First underground heat circulation circuit 20 First underground heat circulation pump 21 First load terminal 22 First Circulating fluid piping 23 First load side circulation circuit 24 First load side circulation pump 25 First return temperature sensor 26 First control means

Claims (2)

1st heat pump which connected the 1st compressor, the refrigerant flow path of the 1st load side heat exchanger, the 1st expansion valve, and the refrigerant flow path of the 1st heat source side heat exchanger cyclically with the 1st refrigerant piping A circuit, an evaporation temperature detecting means for detecting the temperature of the refrigerant on the first heat source side heat exchanger side, a second compressor, a refrigerant flow path of the second load side heat exchanger, a second expansion valve, A second heat pump circuit in which the refrigerant flow path of the second heat source side heat exchanger is annularly connected by a second refrigerant pipe, and the refrigerant of the first heat source side heat exchanger or the second heat source side heat exchanger is heated. The heat source circulation type heat source unit, and the first heat source side heat exchanger and the second heat source side heat exchanger are connected in parallel to the heat source of the heat source unit, and the heat source of the heat source unit and the first heat source unit first heat-source-side circulation circuit is formed by connecting in a ring between at first antifreeze pipe with antifreeze passage of the heat source-side heat exchanger, and the heat of the heat source unit A second heat source side circulation circuit formed by connecting in a ring between the antifreeze flow path of the second heat source side heat exchanger in the second antifreeze piping, a circulating antifreeze to the first heat-source-side circulation circuit A circulating fluid pipe between the first heat source circulating pump, the second heat source circulating pump that circulates the antifreeze liquid in the second heat source circulating circuit, and the circulating fluid flow path of the load terminal and the first load heat exchanger; A load-side circulation circuit connected in a ring shape, a load-side circulation pump that circulates the circulation fluid in the load-side circulation circuit, and a temperature of the circulation fluid flowing into the circulation fluid passage of the first load-side heat exchanger Load temperature detection means for controlling, and control means for controlling these operations, driving the first heat source side circulation pump to circulate the antifreeze liquid, to function the first heat source side heat exchanger as an evaporator , Circulates the circulating fluid by driving the load-side circulation pump Was the first load-side heat exchanger during the heating operation for heating the load side is caused to function as a condenser, the control means, the temperature to be detected is set target heating temperature at the load temperature detecting means In the heat pump device for controlling the frequency or the rotational speed of the first compressor as described above, during the heating operation, the second heat source side circulation pump is driven to circulate the antifreeze liquid, thereby the second heat source side heat exchanger. Is operated as an evaporator and the second load-side heat exchanger is functioned as a condenser, and the circulation flow rate of the antifreeze circulating in the first heat source-side circulation circuit is reduced to reduce the evaporation temperature. When the temperature of the refrigerant detected by the detecting means decreases, the control means sets an upper limit value of the frequency or the rotational speed of the first compressor according to the temperature of the refrigerant detected by the evaporation temperature detecting means. I will set A heat pump device characterized by that. 2. The control means according to claim 1 , wherein the upper limit value of the frequency or the rotational speed of the first compressor is lowered as the temperature of the refrigerant detected by the evaporation temperature detecting means decreases. Heat pump device.

Images