CN103842743B - Heat pump - Google Patents

Abstract

The invention also ensures that the efficiency of the heat pump does not decrease even when an auxiliary heat exchanger is used to regulate the heat balance of the refrigerant circuit. The refrigerant circuit (10) is provided with an auxiliary heat exchanger (1) for exchanging heat between the refrigerant in the refrigerant circuit (10) and outdoor air. The auxiliary heat exchanger (1) is connected to the refrigerant circuit (10) to ensure the connecting passage (4) between the low-stage compressor (11) and the high-stage compressor (12), and the low-stage expansion valve (15) and the high-stage expansion valve (14) ) between the connecting pathway (7) connected.

Description

heat pump

technical field

The present invention relates to a heat pump, and in particular to a heat pump including a refrigerant circuit capable of handling cold heat and warm heat simultaneously.

Background technique

Heat pumps that can handle both heating and cooling loads are known so far. Some of these heat pumps include a refrigerant circuit in which, in addition to a heat exchanger for heating to handle the above-mentioned heating load and a heat exchanger for cooling to handle the above-mentioned cooling load, an auxiliary heat exchanger is connected to the refrigerant circuit device (refer to Patent Document 1).

The auxiliary heat exchanger is adjusted according to the conditions of heating load and cooling load, so as to ensure that the heat balance in the above-mentioned refrigerant circuit will not be unbalanced. In the case where the heating load is greater than the cooling load and the refrigerant circuit releases too much heat, the auxiliary heat exchanger becomes an evaporator to increase the heat absorption to make the heat balance reach equilibrium. That is, the refrigerant condensed in the heating heat exchanger is evaporated in both the cooling heat exchanger and the auxiliary heat exchanger.

On the contrary, when the above-mentioned heating load is smaller than the above-mentioned cooling load and the above-mentioned refrigerant circuit absorbs too much heat, the auxiliary heat exchanger becomes a condenser to increase the heat release to make the heat balance reach a balance. That is, the refrigerant evaporated in the cooling heat exchanger is condensed in both the heating heat exchanger and the auxiliary heat exchanger.

Patent Document 1: Japanese Patent Application Laid-Open No. 2001-349639

Contents of the invention

-Technical problem to be solved by the invention-

This auxiliary heat exchanger allows heat exchange between the outside air and the refrigerant. Therefore, the heat exchange capacity of the auxiliary heat exchanger is not used to handle the heating load and the cooling load, and does not make any contribution to the capacity of the heat pump. However, there is still a problem that a part of the power of the compressor is wasted as power for supplying the refrigerant to the auxiliary heat exchanger, and the efficiency of the heat pump is reduced.

The present invention was made to solve the above-mentioned problems, and an object of the present invention is to enable a heat pump using an auxiliary heat exchanger to operate more efficiently than conventionally to adjust the heat balance of a refrigerant circuit.

-Technical solutions to solve technical problems-

The invention in the first aspect is a refrigeration device, which includes a refrigerant circuit 10 and an auxiliary heat exchanger 1, and a low-stage compression mechanism 11, a high-stage compression mechanism 12, a high-temperature heat exchanger 13, a high-stage expansion mechanism 14, and a low-stage compression mechanism are connected by a refrigerant passage. The expansion mechanism 15 and the low-temperature heat exchanger 16 are connected in sequence to form the refrigerant circuit 10. The refrigerant releases heat to the high-temperature fluid in the above-mentioned high-temperature heat exchanger 13, and the refrigerant absorbs heat from the low-temperature fluid in the above-mentioned low-temperature heat exchanger 16. By evaporating, the refrigeration cycle can be performed in the refrigerant circuit 10 . The above-mentioned auxiliary heat exchanger 1 is connected in the above-mentioned refrigerant circuit 10 to ensure that the refrigerant passage between the above-mentioned low-stage compression mechanism 11 and the above-mentioned high-stage compression mechanism 12 and the refrigerant between the above-mentioned low-stage expansion mechanism 15 and the above-mentioned high-stage expansion mechanism 14 The paths are connected to allow the refrigerant in the refrigerant circuit 10 and the heat source fluid to exchange heat in the auxiliary heat exchanger 1 .

Here, in the case of the heat pump in the prior art, the refrigerant in the refrigerant circuit 10 is circulated by single-stage compression. In order for the auxiliary heat exchanger 1 to function as a condenser, only the auxiliary heat The exchanger 1 communicates with the high-pressure refrigerant piping system (flow path of high-pressure refrigerant flow) of the above-mentioned refrigerant circuit 10 (refer to FIG. 13(A)); in order for the above-mentioned auxiliary heat exchanger 1 to function as an evaporator, only The auxiliary heat exchanger 1 is communicated with the low-pressure refrigerant piping system (flow path through which the low-pressure refrigerant flows) of the above-mentioned refrigerant circuit 10 .

In the first aspect of the invention, the above-mentioned refrigerant circuit 10 is constituted by a two-stage compression and two-stage expansion circuit, and the auxiliary heat exchanger 1 is arranged in the medium-pressure refrigerant piping system of the refrigerant circuit 10 (the medium-pressure refrigerant flows through flow path) (refer to FIG. 13(B)). In this way, when the auxiliary heat exchanger 1 is made to function as a condenser, it is only necessary to supply part of the refrigerant compressed by the low-stage compression mechanism 11 to the auxiliary heat exchanger 1, so that the refrigerant circuit 10 Compression power is reduced.

Furthermore, when the auxiliary heat exchanger 1 is made to function as an evaporator, a part of the refrigerant decompressed by the above-mentioned high-level expansion mechanism is supplied to the auxiliary heat exchanger 1 and evaporated, and then the above-mentioned high-level compression mechanism 12 Suction is enough, so the compression power of the above-mentioned refrigerant circuit 10 is reduced.

The second aspect of the invention is such that, in the first aspect of the invention, the refrigerating device includes the compression mechanism regulator (41). The compression mechanism regulator 41 adjusts the operating capacity of the high-stage compression mechanism 12 according to the heating load of the high-temperature heat exchanger 13; and adjusts the operating capacity of the low-stage compression mechanism 11 according to the cooling load of the low-temperature heat exchanger 16.

In the second aspect of the invention, if the heating load increases, the working capacity of the high-level compression mechanism 12 is increased; if the heating load decreases, the working capacity of the high-level compression mechanism 12 is decreased. Also, if the cooling load increases, the operation capacity of the low-stage compression mechanism 11 is increased; if the cooling load decreases, the operation capacity of the low-stage compression mechanism 11 is decreased.

Here, if the above-mentioned heating load is greater than the above-mentioned cooling load, the working capacity of the above-mentioned high-stage compression mechanism 12 is greater than that of the above-mentioned low-stage compression mechanism 11, and the refrigerant evaporated in the above-mentioned auxiliary heat exchanger 1 is the same as that sprayed from the above-mentioned low-stage compression mechanism 11. The discharged refrigerant is sucked into the above-mentioned advanced compression mechanism 12 together.

On the contrary, if the above-mentioned cooling load is greater than the above-mentioned heating load, the working capacity of the above-mentioned low-stage compression mechanism 11 is greater than that of the above-mentioned high-stage compression mechanism 12, and the refrigerant discharge amount of the above-mentioned low-stage compression mechanism 11 will be higher than that of the above-mentioned high-stage compression mechanism 12. The inhaled dose is large. As a result, the refrigerant discharged from the low-stage compression mechanism 11 and not sucked into the high-stage compression mechanism 12 flows into the auxiliary heat exchanger 1 . By having the auxiliary heat exchanger 1 function as a condenser, the refrigerant is condensed in the auxiliary heat exchanger 1 .

In this way, if the above-mentioned heating load is greater than the above-mentioned cooling load, the above-mentioned auxiliary heat exchanger 1 can be made to function as an evaporator; if the above-mentioned cooling load is greater than the above-mentioned heating load, the above-mentioned auxiliary heat exchanger 1 can be made to function as a condenser effect.

The third invention is such that, in the second invention, the refrigeration device includes switching mechanisms 51, 52 capable of switching between the low suction state and the high suction state. The above-mentioned low-level suction state is: when the above-mentioned heating load is greater than the above-mentioned cooling load, and the above-mentioned auxiliary heat exchanger 1 and the above-mentioned low-temperature heat exchanger 16 both function as evaporators, when the evaporation pressure of the above-mentioned auxiliary heat exchanger 1 and the above-mentioned When the pressure difference of the evaporation pressure of the low-temperature heat exchanger 16 is less than a predetermined value or when the evaporation pressure of the auxiliary heat exchanger 1 is lower than the evaporation pressure of the low-temperature heat exchanger 16, the refrigerant flowing out of the auxiliary heat exchanger 1 Lead to the suction side of the above-mentioned low-stage compression mechanism 11. The above-mentioned high-level suction state is: when the above-mentioned heating load is greater than the above-mentioned cooling load, and the above-mentioned auxiliary heat exchanger 1 and the above-mentioned low-temperature heat exchanger 16 both function as evaporators, when the above-mentioned pressure difference is more than a predetermined value and the above-mentioned auxiliary heat When the evaporation pressure of the exchanger 1 is higher than the evaporation pressure of the low-temperature heat exchanger 16 , the refrigerant flowing out of the auxiliary heat exchanger 1 is guided to the suction side of the high-stage compression mechanism 12 .

Here, the smaller the pressure difference between the evaporating pressure of the auxiliary heat exchanger 1 and the evaporating pressure of the low-temperature heat exchanger 16 is, the closer the suction pressure and the discharge pressure of the low-stage compression mechanism 11 are, and the two-stage compression brings The effect of improving the working efficiency of the heat pump is small. And, if the evaporating pressure of the above-mentioned auxiliary heat exchanger 1 is lower than the evaporating pressure of the above-mentioned low-temperature heat exchanger 16, the pressure of the suction refrigerant and the pressure of the discharge refrigerant of the above-mentioned low-stage compression mechanism 11 will be reversed, and the above-mentioned low-stage compression Mechanism 11 no longer works. Actually, the above-mentioned low-stage compression mechanism 11 operates to reduce the pressure of the suction refrigerant, but since the pressure of the suction refrigerant in this case is lower than the optimum evaporation pressure of the above-mentioned low-temperature heat exchanger 16, the operation efficiency of the heat pump decreases. In addition, the predetermined value is set within a pressure difference range in which the effect of improving the heat pump operation efficiency by two-stage compression can be obtained.

In the third aspect of the invention, when the pressure difference between the evaporation pressure of the auxiliary heat exchanger 1 and the evaporation pressure of the low-temperature heat exchanger 16 is less than a predetermined value or the evaporation pressure of the auxiliary heat exchanger 1 is lower than that of the low-temperature heat exchanger When the evaporating pressure is below 16, the switching mechanisms 51 and 52 are in the low-stage suction state. In this way, the refrigerant evaporated in the auxiliary heat exchanger 1 is sucked into the low-stage compression mechanism 11 .

On the other hand, the pressure difference between the evaporation pressure of the auxiliary heat exchanger 1 and the evaporation pressure of the low-temperature heat exchanger 16 is greater than or equal to a predetermined value and the evaporation pressure of the auxiliary heat exchanger 1 is greater than the evaporation pressure of the low-temperature heat exchanger 16. When the pressure is high, the refrigerant evaporated in the auxiliary heat exchanger 1 is sucked into the high-level compression mechanism 12, so that the heat pump can operate with high efficiency, and the switching mechanisms 51 and 52 are in the high-level suction state.

The fourth aspect of the invention is as follows. In any one of the first to third aspects of the invention, the refrigerating device includes an economizer pipe 53 , a decompression mechanism 54 and an economizer heat exchanger 55 . The economizer pipeline 53 is branched from the refrigerant pipeline between the high-temperature heat exchanger 13 and the high-level expansion mechanism 14 , and connected to the refrigerant pipeline between the low-level compression mechanism 11 and the high-level compression mechanism 12 . The decompression mechanism 54 decompresses the refrigerant in the economizer pipe 53 . The economizer heat exchanger 55 allows the refrigerant decompressed by the decompression mechanism 54 in the economizer pipe 53 to exchange heat with the high-pressure refrigerant flowing from the high-temperature heat exchanger 13 to the advanced expansion mechanism 14 .

In the fourth aspect of the invention, compared with the case where the economizer heat exchanger 55 is not provided, the degree of subcooling of the refrigerant flowing from the high-temperature heat exchanger 13 to the high-stage expansion mechanism 14 can be made larger, and the heat pump efficiency can be increased. Efficient operation becomes possible.

The fifth aspect of the invention is such that, in the first aspect of the invention, the refrigerating apparatus includes the low-stage bypass passage 18 and the compression mechanism adjusting portion 41 . The low-stage bypass passage 18 bypasses the low-stage compression mechanism 11 . When the heating load is greater than the cooling load, the compression mechanism adjustment unit 41 adjusts the operating states of the low-stage compression mechanism 11 and the high-stage compression mechanism 12 while switching to at least a high-stage single compression operation or a two-stage compression operation. . Under the above-mentioned high-level individual compression operation, when the pressure difference between the evaporation pressure of the auxiliary heat exchanger 1 and the evaporation pressure of the low-temperature heat exchanger 16 is less than a predetermined value or the evaporation pressure of the auxiliary heat exchanger 1 is lower than that of the low-temperature heat exchanger When the evaporating pressure of the heat exchanger 16 is lower than that, the working capacity of the above-mentioned high-stage compression mechanism 12 is adjusted according to the heating load of the above-mentioned high-temperature heat exchanger 13, and the operation of the above-mentioned low-stage compression mechanism 11 is stopped. Under the above-mentioned two-stage compression operation, when the pressure difference is above a predetermined value and the evaporation pressure of the auxiliary heat exchanger 1 is higher than the evaporation pressure of the low-temperature heat exchanger 16, the heating load of the high-temperature heat exchanger 13 is adjusted. The working capacity of the above-mentioned high-stage compression mechanism 12 is adjusted according to the cooling load of the above-mentioned low-temperature heat exchanger 16 .

Here, the smaller the pressure difference between the evaporating pressure of the auxiliary heat exchanger 1 and the evaporating pressure of the low-temperature heat exchanger 16, the closer the suction pressure and discharge pressure of the low-stage compression mechanism 11 are, and the heat pump brought about by two-stage compression The effect of improving work efficiency is small. And, if the evaporating pressure of the above-mentioned auxiliary heat exchanger 1 is lower than the evaporating pressure of the above-mentioned low-temperature heat exchanger 16, the pressure of the suction refrigerant and the pressure of the discharge refrigerant of the above-mentioned low-stage compression mechanism 11 will be reversed, and the above-mentioned low-stage compression Mechanism 11 no longer works. Actually, the above-mentioned low-stage compression mechanism 11 operates to reduce the pressure of the suction refrigerant, but since the pressure of the suction refrigerant in this case is lower than the optimum evaporation pressure of the above-mentioned low-temperature heat exchanger 16, the operation efficiency of the heat pump is lowered. In addition, the predetermined value is set within a pressure difference range in which the effect of improving the heat pump operating efficiency by two-stage compression can be obtained.

In the fifth aspect of the invention, when the pressure difference between the evaporation pressure of the auxiliary heat exchanger 1 and the evaporation pressure of the low-temperature heat exchanger 16 is less than a predetermined value or the evaporation pressure of the auxiliary heat exchanger 1 is lower than that of the low-temperature heat exchanger When the evaporating pressure is lower than 16, the above-mentioned low-stage compression mechanism 11 is stopped, and only the above-mentioned high-stage compression mechanism 12 is activated (high-stage individual compression operation). By stopping the operation of the low-stage compression mechanism 11, the refrigerant evaporated in the low-temperature heat exchanger 16 passes through the low-stage bypass passage 18 and is sucked into the high-stage together with the refrigerant evaporated in the auxiliary heat exchanger 1. Compression mechanism 12.

According to the sixth aspect of the invention, in the first aspect of the invention, the refrigerating device includes the high-level bypass passage 19 and the compression mechanism regulator 41 . The high-level bypass passage 19 bypasses the high-level compression mechanism 12 . When the heating load is smaller than the cooling load, the compression mechanism adjustment unit 41 adjusts the operating states of the low-stage compression mechanism 11 and the high-stage compression mechanism 12 while switching to at least a high-stage single compression operation or a two-stage compression operation. . Under the above-mentioned low-stage individual compression operation, when the pressure difference between the condensation pressure of the auxiliary heat exchanger 1 and the condensation pressure of the high-temperature heat exchanger 13 is less than a predetermined value or the condensation pressure of the auxiliary heat exchanger 1 is within the above-mentioned high-temperature heat exchange When the condensing pressure of the device 13 is above, the above-mentioned high-stage compression mechanism 12 is stopped, and the working capacity of the above-mentioned low-stage compression mechanism 11 is adjusted according to the cooling load of the above-mentioned low-temperature heat exchanger 16 . Under the above-mentioned two-stage compression operation, when the above-mentioned pressure difference is above a predetermined value and the condensation pressure of the above-mentioned auxiliary heat exchanger 1 is lower than the condensation pressure of the above-mentioned high-temperature heat exchanger 13, the heating load of the above-mentioned high-temperature heat exchanger 13 is adjusted. The working capacity of the above-mentioned high-stage compression mechanism 12 is adjusted according to the cooling load of the above-mentioned low-temperature heat exchanger 16 .

Here, the smaller the pressure difference between the condensing pressure of the above-mentioned auxiliary heat exchanger 1 and the condensing pressure of the above-mentioned high-temperature heat exchanger 13 is, the closer the suction pressure and discharge pressure of the above-mentioned advanced compression mechanism 12 are, and the heat pump brought about by two-stage compression The effect of improving work efficiency is even smaller. Moreover, if the condensing pressure of the above-mentioned auxiliary heat exchanger 1 is higher than the condensing pressure of the above-mentioned high-level compression mechanism 12, the pressure of the suction refrigerant and the pressure of the discharge refrigerant of the above-mentioned high-level compression mechanism 12 will be reversed, and the above-mentioned high-level compression mechanism 12 doesn't work anymore. Actually, the above-mentioned advanced compression mechanism 12 operates to increase the pressure of the discharged refrigerant, but since the pressure of the discharged refrigerant is higher than the optimum condensation pressure of the above-mentioned high-temperature heat exchanger 13 in this case, the operation efficiency of the heat pump decreases. . In addition, the predetermined value is set within a pressure difference range in which the effect of improving the heat pump operating efficiency by two-stage compression can be obtained.

In the sixth aspect of the invention, when the pressure difference between the condensing pressure of the auxiliary heat exchanger 1 and the condensing pressure of the high-temperature heat exchanger 13 is less than a predetermined value or the condensing pressure of the auxiliary heat exchanger 1 is lower than that of the high-temperature heat exchanger 13 When the condensing pressure is above the condensing pressure, the above-mentioned high-stage compression mechanism 12 is stopped, and only the above-mentioned low-stage compression mechanism 11 is started (low-stage independent compression action). By stopping the operation of the high-stage compression mechanism 12 , the refrigerant discharged from the low-stage compression mechanism 11 is divided and flows into the auxiliary heat exchanger 1 and the high-stage bypass passage 19 .

The seventh aspect of the invention is as follows. In any one of the second to sixth aspects of the invention, the refrigerating device includes a flow regulating mechanism 2 and a flow regulating mechanism adjusting part 43, and the flow regulating mechanism 2 convects the flow through the auxiliary heat exchanger. 1 The refrigerant flow rate is adjusted. When the heating load is greater than the cooling load, the flow rate adjusting mechanism regulator 43 adjusts the flow rate adjusting mechanism 2 so that the degree of superheat of the refrigerant flowing out of the auxiliary heat exchanger 1 becomes a predetermined value.

In the seventh aspect of the invention, when the heating load is greater than the cooling load and the auxiliary heat exchanger 1 functions as an evaporator, the flow into the auxiliary heat exchanger 1 can be controlled by the operation of the adjustment unit 43 of the flow adjustment mechanism. The refrigerant evaporates reliably.

The eighth aspect of the invention is as follows. In any one of the second to sixth aspects of the invention, the refrigerating device includes a flow regulating mechanism 2 and a regulating part 43 of the flow regulating mechanism. The flow rate adjustment mechanism 2 adjusts the flow rate of the refrigerant flowing through the auxiliary heat exchanger 1 . When the heating load is smaller than the cooling load, the flow rate adjusting mechanism regulator 43 adjusts the flow rate adjusting mechanism 2 so that the subcooling degree of the refrigerant flowing out of the auxiliary heat exchanger 1 becomes a predetermined value.

In the eighth invention, when the heating load is smaller than the cooling load and the auxiliary heat exchanger 1 functions as a condenser, it is possible to make the flow into the auxiliary heat exchanger 1 The refrigerant condenses reliably.

The ninth aspect of the invention is that, in any one of the second to sixth aspects of the invention, the refrigerating device includes a high-level expansion mechanism regulator (44). When the heating load is greater than the cooling load, the high-level expansion mechanism regulator 44 sets the high-level expansion mechanism 14 to fully open.

In the ninth aspect of the invention, the flow of the refrigerant to the auxiliary heat exchanger 1 can be adjusted only by the flow rate adjustment mechanism 2 by fully opening the high-level expansion mechanism 14 .

According to the tenth aspect of the invention, in any one of the second to eighth aspects of the invention, the refrigerating device includes an advanced expansion mechanism regulator (44). When the heating load is smaller than the cooling load, the advanced expansion mechanism regulator 44 adjusts the advanced expansion mechanism 14 so that the refrigerant temperature at the outlet of the advanced expansion mechanism 14 reaches the outlet of the auxiliary heat exchanger 1 The temperature between the refrigerant temperature and the refrigerant temperature at the outlet of the above-mentioned low-temperature heat exchanger 16. .

In the tenth aspect of the invention, the pressure of the refrigerant flowing out of the high-level expansion mechanism (14) can be reliably set to the intermediate pressure of the refrigerant circuit (10).

-The effect of the invention-

According to the present invention, compared with the case where the above-mentioned auxiliary heat exchanger 1 is arranged in the high-pressure refrigerant piping system and the low-pressure refrigerant piping system, the above-mentioned auxiliary heat exchanger 1 is arranged in the medium-pressure refrigerant of the above-mentioned refrigerant circuit 10 After the pipe system, the compression power of the refrigerant circuit 10 for supplying the refrigerant to the auxiliary heat exchanger 1 can be reduced. A desired amount of refrigerant can flow to the auxiliary heat exchanger 1 without control. In this way, the working efficiency of the above-mentioned heat pump can be made higher than that of the prior art.

According to the second aspect of the invention, by adjusting the high-stage compressor 12 according to the heating load and adjusting the low-stage compression mechanism 11 according to the cooling load, the auxiliary heat exchanger 1 can be operated when the heating load is greater than the cooling load. Functioning as an evaporator: When the cooling load is greater than the heating load, the auxiliary heat exchanger 1 can function as a condenser. In this way, the auxiliary heat exchanger 1 can be used as an evaporator or a condenser according to the conditions of the heating load and the cooling load, and it is not necessary to provide a switching valve in the refrigerant circuit 10 .

According to the third aspect of the invention, the switching mechanisms 51 and 52 switch between the low-stage suction state and the high-stage suction state according to the evaporation pressures of the auxiliary heat exchanger 1 and the low-temperature heat exchanger 16 . In this way, the refrigerant evaporated in the auxiliary heat exchanger 1 can be sucked into the low-stage compression mechanism 11 or the high-stage compression mechanism 12 as needed, so that the heat pump can always be operated efficiently.

According to the fourth aspect of the invention, the degree of subcooling of the refrigerant flowing from the high-temperature heat exchanger 13 to the advanced expansion mechanism 14 can be increased compared to the case where the economizer heat exchanger 55 is not provided. In this way, the efficiency of the heat pump described above can be improved.

According to the fifth aspect of the invention, the operation of the compression mechanism adjustment unit 41 is switched to a two-stage compression operation or a high-stage single compression operation according to the evaporation pressures of the auxiliary heat exchanger 1 and the low-temperature heat exchanger 16 . This makes it possible to operate the heat pump with two-stage compression or single-stage compression, as required, so that the heat pump can always operate with high efficiency.

According to the sixth aspect of the invention, the operation of the compression mechanism adjustment unit 41 is switched to a two-stage compression operation or a low-stage single compression operation according to the condensation pressures of the auxiliary heat exchanger 1 and the high-temperature heat exchanger 13 . This makes it possible to operate the heat pump with two-stage compression or single-stage compression, as required, so that the heat pump can always operate with high efficiency.

According to the seventh aspect of the invention, the refrigerant flowing into the auxiliary heat exchanger 1 can be completely evaporated by the adjustment unit 43 of the flow adjustment mechanism, so that the heat exchange amount of the auxiliary heat exchanger 1 can be ensured. In this way, the heat balance of the refrigerant circuit 10 can be reliably balanced even in a state where the heating load is greater than the cooling load.

According to the eighth aspect of the invention, the refrigerant flowing into the auxiliary heat exchanger 1 can be reliably condensed by the adjustment unit 43 of the flow adjustment mechanism, and the heat exchange amount of the auxiliary heat exchanger 1 can be ensured. In this way, even in a state where the heating load is smaller than the cooling load, the heat balance of the refrigerant circuit 10 can be reliably brought into balance.

According to the ninth aspect of the invention, the flow of the refrigerant to the auxiliary heat exchanger 1 can be adjusted using only the flow rate adjustment mechanism 2 . This makes it possible to simplify the work of controlling the flow rate of the refrigerant flowing into the above-mentioned auxiliary heat exchanger 1 .

According to the tenth aspect of the invention, the pressure of the refrigerant flowing out of the advanced expansion mechanism (14) can be reliably set to the intermediate pressure of the refrigerant circuit (10), so that the refrigerant and the heat source fluid can be reliably transferred in the auxiliary heat exchanger (1). heat exchange.

Description of drawings

[ Fig. 1 ] Fig. 1 is a refrigerant circuit diagram of a heat pump according to the present embodiment.

[ Fig. 2] Fig. 2 is a diagram showing the flow of refrigerant in the overheating operation in the present embodiment.

[ Fig. 3] Fig. 3 is a diagram showing the flow of refrigerant in the overcooling operation in the present embodiment.

[ Fig. 4] Fig. 4 is a diagram showing the flow of the refrigerant in the heating-only operation in the present embodiment.

[ Fig. 5] Fig. 5 is a diagram showing the flow of refrigerant in the cooling-only operation in the present embodiment.

[ Fig. 6] Fig. 6 is a refrigerant circuit diagram of a heat pump according to Modification 1 of the present embodiment.

[ Fig. 7] Fig. 7 is a refrigerant circuit diagram of a heat pump according to Modification 2 of the present embodiment.

[ Fig. 8] Fig. 8 is a refrigerant circuit diagram of a heat pump according to Modification 3 of the present embodiment.

[ Fig. 9] Fig. 9 is a diagram showing the flow of refrigerant in a high-level individual compression operation in Modification 3. [Fig.

[ Fig. 10] Fig. 10 is a diagram showing the flow of refrigerant in a low-stage individual compression operation in Modification 3. [Fig.

[ Fig. 11] Fig. 11 is a diagram showing a configuration of a controller.

[ Fig. 12] Fig. 12 is a refrigerant circuit diagram of a heat pump according to Modification 4 of the present embodiment.

[Fig. 13] Fig. 13 is a diagram schematically showing the relationship between each heat exchanger and the refrigeration cycle on the P-h line diagram, (A) is a diagram in which an auxiliary heat exchanger is installed in a high-pressure refrigerant piping system, (B) is a diagram in which the auxiliary heat exchanger is installed in the medium-pressure refrigerant piping system.

detailed description

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

The heat pump in this embodiment is an industrially used heat pump. The heat pump is capable of taking out both cold and warm heat at the same time. The heat pump is provided with a refrigerant circuit 10 and a controller 40 .

1 Refrigerant circuit-

The above-mentioned refrigerant circuit 10 utilizes two-stage compression and two-stage expansion to perform a refrigeration cycle. In this refrigerant circuit 10, a low-stage compressor (low-stage compression mechanism) 11, a high-stage compressor (high-stage compression mechanism) 12, a heating heat exchanger (high-temperature heat exchanger) 13, and a high-stage expansion valve (high-stage expansion mechanism) are provided. 14. Low-stage expansion valve (low-stage expansion mechanism) 15, cooling heat exchanger (low-temperature heat exchanger) 16, flow regulating valve (flow regulating mechanism) 2 and auxiliary heat exchanger 1.

The above-mentioned low-stage compressor 11 and the above-mentioned high-stage compressor 12 are all completely hermetic compressors, the above-mentioned low-stage compressor 11 is connected with a low-stage frequency converter (not shown), and the above-mentioned high-level compressor 12 is connected with a high-level frequency converter ( not shown). The rotational speeds of the respective compressors 11, 12 can be varied using these frequency converters. The discharge port of the above-mentioned low-stage compressor 11 and the suction port of the above-mentioned high-stage compressor 12 are connected by a connecting pipe 4 on the compressor side. A check valve CV1 is attached to the connecting pipe 4 at a position close to the above-mentioned low-stage compressor 11 . The check valve CV1 allows the refrigerant to flow from the low-stage compressor 11 to the high-stage compressor 12 and prevents the refrigerant from flowing in the opposite direction.

The heating heat exchanger 13 includes a refrigerant flow path 13a and a water flow path 13b. The inlet of the refrigerant flow path 13a is connected to the discharge port of the high-grade compressor 12 by the first refrigerant pipe 5, and the outlet of the refrigerant flow path 13a and the inlet of the high-grade expansion valve 14 are connected by the second refrigeration pipe 5. Agent pipeline 6 is connected. On the other hand, the water flow path 13 b of the heating heat exchanger 13 communicates with the warm water circuit 30 . A warm water pump 31 and a warm water tank 32 are connected to the warm water circuit 30 . The heating heat exchanger 13 is configured such that the high-pressure refrigerant is cooled when the high-pressure refrigerant discharged from the high-stage compressor 12 passes through the refrigerant flow path 13a and the water flowing out of the warm water pump 31 passes through the water flow path 13b. agent and the above water for heat exchange.

Both the high-stage expansion valve 14 and the low-stage expansion valve 15 are electronic expansion valves with adjustable openings. The outflow port of the high-stage expansion valve 14 and the inflow port of the low-stage expansion valve 15 are connected by an expansion valve-side connecting pipe 7 .

The cooling heat exchanger 16 includes a refrigerant flow path 16a and a water flow path 16b. The inlet of the refrigerant flow path 16a is connected to the outlet of the low-stage expansion valve 15 by the third refrigerant pipe 8, and the outlet of the refrigerant flow path 16a and the suction port of the low-stage compressor 11 are connected by a fourth refrigerant pipe 8. Agent pipeline 9 is connected. On the other hand, the water flow path 16 b in the cooling heat exchanger 16 communicates with the cold water circuit 33 . A cold water pump 34 and a cold water tank 35 are connected to the cold water circuit 33 . The cooling heat exchanger 16 is configured so that when the low-pressure refrigerant flowing out of the low-stage expansion valve 15 passes through the refrigerant flow path 16a and the water flowing out of the cold water pump 34 passes through the water flow path 16b, the low-pressure refrigerant and the low-pressure refrigerant flow together. The above water is subjected to heat exchange.

As described above, the refrigerant circuit 10 has a low-stage compressor 11, a high-stage compressor 12,

The heat exchanger 13 for heating, the high-stage expansion valve 14 , the low-stage expansion valve 15 , and the heat exchanger 16 for cooling are sequentially connected to form a closed circuit. The above-mentioned auxiliary heat exchanger 1 and the above-mentioned flow regulating valve 2 are connected in this closed circuit.

<Auxiliary heat exchanger>

The auxiliary heat exchanger 1 can realize the heat balance of the refrigeration cycle involved in the refrigerant circuit 10 .

The above-mentioned auxiliary heat exchanger 1 is, for example, a horizontal fin-and-tube heat exchanger, and has a refrigerant passage 1a and an air passage (not shown). One end of the refrigerant passage 1a of the auxiliary heat exchanger 1 is connected with a branch pipe 3a branched from the connecting pipe 4 on the compressor side; the other end is connected with a branch pipe 3b branched from the expansion valve side connecting pipe 7. . In addition, the above-mentioned flow regulating valve 2 is provided on the branch pipe 3b.

Furthermore, a blower fan 17 is provided near the above-mentioned auxiliary heat exchanger 1 . The auxiliary heat exchanger 1 is configured such that the refrigerant discharged from the low-stage compressor 11 or the refrigerant discharged from the high-stage expansion valve 14 passes through the refrigerant passage 1a, and air from the blower fan 17 passes through the air passage. On occasion, the above-mentioned refrigerant and outdoor air perform heat exchange.

-controller-

The controller 40 controls the operating state of the heat pump. As shown in FIG. 11 , the controller 40 is provided with a compressor adjustment unit (compression mechanism adjustment unit) 41, a load determination unit 42, a flow adjustment valve adjustment unit (flow adjustment mechanism adjustment unit) 43, an advanced expansion valve adjustment unit ( High-stage expansion mechanism adjustment part) 44 and low-stage expansion valve adjustment part (low-stage expansion mechanism adjustment part) 45. The plurality of temperature sensors 21 to 26 are electrically connected to the controller 40 described above.

Specifically, the plurality of temperature sensors 21 to 26 are the advanced expansion valve temperature sensor 21 that detects the temperature of the refrigerant at the outlet of the above-mentioned advanced expansion valve 14, and the cooling heat exchanger that detects the temperature of the refrigerant at the outlet of the cooling heat exchanger 16. Temperature sensor 22, the first and second auxiliary heat exchange temperature sensors 23, 24 for detecting the temperature of the refrigerant before and after passing through the auxiliary heat exchanger 1, and the warm water temperature sensor for detecting the temperature of warm water at the outlet of the heating heat exchanger 13 25 and a cold water temperature sensor 26 that detects the temperature of the cold water at the outlet of the cooling heat exchanger 16 .

<Compressor adjustment department>

The detection values of the above-mentioned warm water temperature sensor 25 and the above-mentioned cold water temperature sensor 26, the warm water setting value of the warm water temperature at the outlet of the above-mentioned heating heat exchanger 13, and the cold water setting of the cold water temperature at the outlet of the above-mentioned cooling heat exchanger 16 The value is input to the above-mentioned compressor adjustment unit 41.

When the detection value of the above-mentioned warm water temperature sensor 25 is lower than the above-mentioned warm water set value, the above-mentioned compressor adjustment unit 41 transmits a signal for increasing the speed of the above-mentioned high-level compressor 12 to the high-level frequency converter; When the detection value of the temperature sensor 25 is higher than the warm water setting value, the compressor adjustment unit 41 sends a signal for reducing the rotation speed of the high-stage compressor 12 to the high-stage inverter.

When the detection value of the above-mentioned cold water temperature sensor 26 is higher than the above-mentioned cold water setting value, the above-mentioned compressor regulator 41 sends a signal for increasing the speed of the above-mentioned low-stage compressor 11 to the low-stage inverter; When the detection value of the temperature sensor 26 is lower than the cold water setting value, the compressor regulator 41 sends a signal for reducing the rotation speed of the low-stage compressor 11 to the low-stage inverter.

In this way, the compressor adjusting unit 41 adjusts the working capacity of the high-stage compressor 12 according to the heating load, and adjusts the working capacity of the low-stage compressor 11 according to the cooling load.

<Load Judgment Unit>

The frequency command values of the low-stage and high-stage inverters are input to the load determination unit 42 . In this load determination unit 42 , the cooling load is detected based on the frequency command value of the low-stage inverter, and the heating load is detected based on the frequency command value of the high-stage inverter. When the frequency command value of the high-level inverter is larger than the frequency command value of the low-level inverter, the load judging unit 42 will make a judgment that the heating load is greater than the cooling load, and output an excessive heating signal; When the frequency command value of the side inverter is smaller than the frequency command value of the low-side inverter, the load judging unit 42 judges that the heating load is smaller than the cooling load, and outputs an excessive cooling signal.

<Flow adjustment valve adjustment part>

The detection values of the first and second auxiliary heat exchanger temperature sensors 23 and 24 and the judgment signal of the load judging part 42 are input into the flow regulating valve regulating part 43; The detection value of the internal temperature sensor (not shown) of the auxiliary heat exchanger is input to the above-mentioned flow regulating valve regulating unit 43 .

When the excessive heating signal is input into the flow regulating valve regulating part 43 from the above-mentioned load judging part 42, the flow regulating valve regulating part 43 uses the detection value of the above-mentioned auxiliary heat exchanger internal temperature sensor as the evaporation temperature of the auxiliary heat exchanger 1, And according to the evaporating temperature, the outlet superheat degree of the auxiliary heat exchanger 1 is calculated from the detection value of the second auxiliary heat exchange temperature sensor 24 . Then, an opening adjustment signal is appropriately sent from the flow regulating valve adjusting part 43 to the flow regulating valve 2, and the opening of the flow regulating valve 2 is adjusted so that the outlet superheat reaches a predetermined value (for example, 3°C).

On the other hand, when an excessive cooling signal is input from the load determination unit 42, the flow control valve adjustment unit 43 sets the detection value of the auxiliary heat exchanger internal temperature sensor as the condensation temperature of the auxiliary heat exchanger 1, and The degree of subcooling at the outlet of the auxiliary heat exchanger 1 is calculated from the detection value of the first auxiliary heat exchanger temperature sensor 23 based on the condensation temperature. Then, an opening adjustment signal is appropriately sent from the flow regulating valve adjusting part 43 to the flow regulating valve 2, and the opening of the flow regulating valve 2 is adjusted so that the outlet supercooling degree reaches a predetermined value (for example, 2° C.).

<Advanced Expansion Valve Regulator>

The detection value of the above-mentioned advanced expansion valve temperature sensor 21, the detection value of the above-mentioned cooling heat exchanger temperature sensor 22, the detection value of the above-mentioned second auxiliary heat exchanger temperature sensor 24, and the judgment signal of the above-mentioned load judging part 42 are input into the above-mentioned advanced expansion valve regulating part 44.

When the overheating signal is input to the high-level expansion valve adjustment unit 44 from the above-mentioned load judging unit 42, the opening adjustment signal will be output from the high-level expansion valve adjustment unit 44 to the above-mentioned high-level expansion valve 14, and the result is that the high-level expansion valve 14 The opening becomes fully open.

On the other hand, when an excessive cooling signal is input from the load judging unit 42, an opening adjustment signal is appropriately sent from the high-level expansion valve adjustment unit 44 to the high-level expansion valve 14 to adjust the opening of the high-level expansion valve 14, so that the refrigerant temperature at the outlet of the advanced expansion valve 14 (the detection value of the advanced expansion valve temperature sensor 21) reaches the refrigerant temperature at the outlet of the auxiliary heat exchanger 1 (the detection value of the second auxiliary heat exchanger temperature sensor 24) The temperature between the refrigerant temperature at the outlet of the low-temperature heat exchanger 16 (the detection value of the cooling heat exchanger temperature sensor 22).

<Low stage expansion valve regulator>

The detection value of the cooling heat transfer temperature sensor 22 is input to the low-stage expansion valve regulator 45 . A detection value of a cooling heat exchanger internal temperature sensor (not shown) that detects the temperature of the refrigerant flowing in the cooling heat exchanger 16 is input to the low-stage expansion valve regulator 45 .

The low-stage expansion valve regulator 45 uses the detection value of the cooling heat exchanger internal temperature sensor as the evaporation temperature of the cooling heat exchanger 16, and calculates the cooling heat exchanger 16 from the detection value of the cooling heat exchanger temperature sensor 22 based on the evaporation temperature. The outlet superheat of the heat exchanger 16. Then,

An opening adjustment signal is appropriately sent from the low-stage expansion valve regulator 45 to the low-stage expansion valve 15, and the opening of the low-stage expansion valve 15 is adjusted so that the outlet superheat reaches a predetermined value (for example, 3°C).

The working condition of a heat pump-

Next, how the above heat pump works will be explained. This heat pump can perform excessive heating operation or excessive cooling operation according to the conditions of heating load and cooling load without using a switching valve or the like. First, the overheating operation and the overcooling operation will be described, and then the individual heating operation and the individual cooling operation will be described.

<Excessive heating operation>

The excessive heating operation shown in FIG. 2 is an operation performed when the heating load of the heat pump is larger than the cooling load. In addition, in this embodiment, the outdoor air temperature is 15°C, the warm water setting value set in the compressor adjustment unit 41 is 65°C, and the cold water setting value is 7°C, which is necessary for the heat pump. Overheating operation performed with the heating capacity at 90% and the required cooling capacity at 60%.

Under the overheating operation, the compressor adjustment part 41 of the controller 40 is used to adjust the rotation speed of the high-grade compressor 12 so that the temperature of the warm water at the outlet of the heat exchanger 13 for heating reaches the set value of warm water, that is, 65°C. Utilize the compressor regulating part 41 of the above-mentioned controller 40 to adjust the rotating speed of the above-mentioned low-stage compressor 11, so that the temperature of the cold water at the outlet of the above-mentioned cooling heat exchanger 16 reaches the set value of cold water, that is, 7°C.

The above-mentioned advanced expansion valve 14 is set to be fully opened by the above-mentioned advanced expansion valve adjusting part 44; to 3°C; the opening of the low-stage expansion valve 15 is adjusted by the low-stage expansion valve regulator 45 so that the outlet superheat of the cooling heat exchanger 16 reaches 3°C.

Since the heating load is larger than the cooling load after the above-mentioned low-stage compressor 11 and the above-mentioned high-stage compressor 12 start to operate, the rotation speed of the above-mentioned high-stage compressor 12 is higher than the rotation speed of the above-mentioned low-stage compressor 11, and the refrigerant sucked by the high-stage compressor 12 The amount is larger than the refrigerant discharge amount of the low-stage compressor 11.

Therefore, the refrigerant evaporated in the auxiliary heat exchanger 1 is sucked into the high-stage compressor 12 together with the refrigerant discharged from the low-stage compressor 11 . That is, the refrigerant flows from the expansion valve side to the compressor side (from the left side to the right side of the auxiliary heat exchanger 1 shown in FIG. 2 ) in the auxiliary heat exchanger 1 .

The refrigerant discharged from the high-stage compressor 12 releases heat to water in the warm water circuit 30 in the heating heat exchanger 13 to be condensed. At this time, the condensation temperature of the heating heat exchanger 13 is about 70° C., and the water in the warm water circuit 30 is heated to 65° C. due to the heat released by the refrigerant in the heating heat exchanger 13 . The refrigerant condensed in the heating heat exchanger 13 passes through the high-level expansion valve 14 set to fully open by the high-level expansion valve regulator 44 , and then divides into two branch flows.

A part of the branched refrigerant is depressurized by the low-stage expansion valve 15 , absorbs heat from the water in the cold water circuit 33 in the cooling heat exchanger 16 , and evaporates. At this time, the evaporation temperature of the cooling heat exchanger 16 is about 0° C., and the water in the cold water circuit 33 is cooled to 7° C. due to the heat absorbed by the refrigerant in the cooling heat exchanger 16 . The refrigerant evaporated in the cooling heat exchanger 16 is sucked into the low-stage compressor 11 and compressed, and then sprayed toward the suction side of the high-stage compressor 12 .

On the other hand, the other subflow of the divided refrigerant is depressurized by the flow regulating valve 2 and evaporates by absorbing heat from the outdoor air in the auxiliary heat exchanger 1 . The evaporation temperature at this time is about 10°C. The refrigerant evaporated in the auxiliary heat exchanger 1 merges with the refrigerant discharged from the low-stage compressor 11, is drawn into the high-stage compressor 12, is compressed, and is sprayed to the heating heat exchanger 13 again. .

Thus, when the heating load is greater than the cooling load, the refrigerant in the auxiliary heat exchanger 1 flows from the expansion valve side to the compressor side, and the auxiliary heat exchanger 1 functions as an evaporator. Therefore, the refrigerant circuit 10 can perform a refrigeration cycle while maintaining heat balance.

<Excess cooling operation>

The overcooling operation shown in FIG. 3 is an operation performed when the heating load of the heat pump is smaller than the cooling load. In addition, in this embodiment, the outdoor air temperature is 15°C, the hot water setting value set in the compressor adjustment unit 41 is 65°C, and the cold water setting value is 7°C, which is necessary for the heat pump. Excessive cooling operation performed when the heating capacity is 90% and the required cooling capacity is 60%.

In this overcooling operation, the compressor adjustment unit 41 of the controller 40 is used to adjust the rotation speed of the high-grade compressor 12 so that the temperature of the warm water at the outlet of the heating heat exchanger 13 reaches the set value of warm water, that is, 65°C. Utilize the compressor regulating part 41 of the above-mentioned controller 40 to adjust the rotating speed of the above-mentioned low-stage compressor 11, so that the temperature of the cold water at the outlet of the above-mentioned cooling heat exchanger 16 reaches the set value of cold water, that is, 7°C.

The opening degree of the above-mentioned advanced expansion valve 14 is adjusted by the above-mentioned advanced expansion valve regulator 44, so that the refrigerant temperature at the outlet of the above-mentioned advanced expansion valve 14 reaches the refrigerant temperature at the outlet of the auxiliary heat exchanger 1 and the cooling heat exchange The temperature between the refrigerant temperature at the outlet of the device 16; the opening degree of the above-mentioned flow regulating valve 2 is adjusted by the above-mentioned flow regulating valve regulating part 43, so that the outlet subcooling degree of the above-mentioned auxiliary heat exchanger 1 reaches 2 ° C; by the above-mentioned The lower-stage expansion valve adjustment unit 45 adjusts the opening of the lower-stage expansion valve 15 so that the degree of superheat at the outlet of the cooling heat exchanger 16 becomes 3°C.

Since the heating load is smaller than the cooling load after the above-mentioned low-stage compressor 11 and the above-mentioned high-stage compressor 12 start to operate, the rotation speed of the above-mentioned high-stage compressor 12 is lower than that of the above-mentioned low-stage compressor 11, and the refrigerant sucked by the high-stage compressor 12 The amount is smaller than the refrigerant discharge amount of the low-stage compressor 11.

If so, the high-stage compressor 12 cannot suck all the refrigerant discharged from the low-stage compressor 11 , and part of the refrigerant discharged from the low-stage compressor 11 flows to the auxiliary heat exchanger 1 . That is, the refrigerant flows from the compressor side to the expansion valve side (from the right side to the left side of the auxiliary heat exchanger 1 shown in FIG. 3 ) in the auxiliary heat exchanger 1 .

The refrigerant diverted from the low-stage compressor 11 to the high-stage compressor 12 is compressed in the high-stage compressor 12 and sprayed toward the heating heat exchanger 13 . The refrigerant discharged from the high-stage compressor 12 releases heat to water in the warm water circuit 30 in the heating heat exchanger 13 to be condensed. The condensation temperature at this time is about 70° C., and the water in the warm water circuit 30 is heated to 65° C. due to the heat released by the refrigerant in the heating heat exchanger 13 . The refrigerant condensed in the heating heat exchanger 13 is decompressed by the advanced expansion valve 14 .

On the other hand, the refrigerant diverted from the low-stage compressor 11 to the auxiliary heat exchanger 1 is condensed in the auxiliary heat exchanger 1 and then flows into the flow control valve 2 . The condensation temperature in the auxiliary heat exchanger 1 at this time is about 20°C. The refrigerant flowing to the flow regulating valve 2 is decompressed by the flow regulating valve 2 , and then joins the refrigerant flowing out of the high-stage expansion valve 14 to flow to the low-stage expansion valve 15 .

The refrigerant flowing into the low-stage expansion valve 15 is decompressed, absorbs heat from the water in the cold water circuit 33 in the cooling heat exchanger 16 , and evaporates. At this time, the evaporation temperature of the cooling heat exchanger 16 is about 0° C., and the water in the cold water circuit 33 is cooled to 7° C. due to the heat absorbed by the refrigerant in the cooling heat exchanger 16 . The refrigerant evaporated in the cooling heat exchanger 16 is sucked into the low-stage compressor 11 and compressed, and then sprayed toward the auxiliary heat exchanger 1 and the high-stage compressor 12 again.

Thus, when the heating load is smaller than the cooling load, the flow direction of the refrigerant in the auxiliary heat exchanger 1 is from the compressor side to the expansion valve side, and the auxiliary heat exchanger 1 functions as a condenser. Therefore, the refrigerant circuit 10 can perform a refrigeration cycle while maintaining heat balance.

<Individual heating operation>

The sole heating operation shown in FIG. 4 is an operation performed with the above-mentioned heating load and without the above-mentioned cooling load. In this heating-only operation, the high-stage compressor 12 is started, and the low-stage compressor 11 is stopped. The above-mentioned high-stage expansion valve 14 is in a fully open state, and the above-mentioned low-stage expansion valve 15 is in a fully closed state.

The refrigerant discharged from the high-stage compressor 12 releases heat to water in the warm water circuit 30 in the heating heat exchanger 13 to be condensed. At this time, the water in the warm water circuit 30 is heated due to the heat released by the refrigerant in the heating heat exchanger 13 . The refrigerant condensed in the heating heat exchanger 13 passes through the advanced expansion valve 14 in a fully opened state, and then flows into the flow rate regulating valve 2 .

The refrigerant flowing into the flow rate regulating valve 2 is decompressed by the flow rate regulating valve 2 to become a low-pressure refrigerant, and absorbs heat from the outdoor air in the auxiliary heat exchanger 1 to be evaporated. The refrigerant evaporated in the auxiliary heat exchanger 1 is sucked into the high-stage compressor 12 and compressed, and sprayed to the heating heat exchanger 13 again. In this way, the heating heat exchanger 13 serves as a condenser and the auxiliary heat exchanger 1 serves as an evaporator, and the heating load is processed in the heating heat exchanger 13 .

<Individual cooling operation>

The individual cooling operation shown in FIG. 5 is an operation performed with the above-mentioned cooling load and without the above-mentioned heating load. In this individual cooling operation, the above-mentioned high-stage compressor 12 is stopped, and the above-mentioned low-stage compressor 11 is started. Furthermore, the above-mentioned high-stage expansion valve 14 is in a fully closed state, and the above-mentioned low-stage expansion valve 15 is in a fully open state.

The refrigerant discharged from the low-stage compressor 11 releases heat to the outdoor air in the auxiliary heat exchanger 1 to condense, and is decompressed by the flow regulating valve 2 to become a low-pressure refrigerant. The low-pressure refrigerant absorbs heat from the water in the cold water circuit 33 in the cooling heat exchanger 16 after passing through the fully opened low-stage expansion valve 15 to evaporate. At this time, the water in the cold water circuit 33 is cooled by the refrigerant in the cooling heat exchanger 16 absorbing heat. The refrigerant evaporated in the cooling heat exchanger 16 is sucked into the low-stage compressor 11 and compressed, and then sprayed to the auxiliary heat exchanger 1 again. In this way, the auxiliary heat exchanger 1 serves as a condenser and the cooling heat exchanger 16 serves as an evaporator, and the cooling load is processed by the cooling heat exchanger 16 .

-Effect of Embodiment-

According to this embodiment, compared with the case where the above-mentioned auxiliary heat exchanger 1 is arranged in the high-pressure refrigerant piping system and the low-pressure refrigerant piping system, the above-mentioned auxiliary heat exchanger 1 is arranged in the medium-pressure refrigeration system of the above-mentioned refrigerant circuit 10 After entering the refrigerant piping system, the compression power of the refrigerant circuit 10 for supplying the refrigerant to the auxiliary heat exchanger 1 can be reduced. In this way, the efficiency of the heat pump described above can be prevented from being lowered. A desired amount of refrigerant can flow to the auxiliary heat exchanger 1 without control. In this way, the working efficiency of the above-mentioned heat pump can be made higher than that of the prior art.

According to this embodiment, by adjusting the high-stage compressor 12 according to the heating load and the low-stage compressor 11 according to the cooling load, the auxiliary heat exchanger 1 can be evaporated together when the heating load is greater than the cooling load. The role of the device; in the case of the above-mentioned cooling load is greater than the above-mentioned heating load, the above-mentioned auxiliary heat exchanger 1 can be made to function as a condenser. In this way, the auxiliary heat exchanger 1 can be used as an evaporator or a condenser according to the conditions of the heating load and the cooling load, and it is not necessary to provide a switching valve in the refrigerant circuit 10 .

According to the present embodiment, the refrigerant flowing into the auxiliary heat exchanger 1 can be completely evaporated by the flow rate regulating valve adjustment unit 43 , and the heat exchange amount of the auxiliary heat exchanger 1 can be ensured. In this way, the heat balance of the refrigerant circuit 10 can be reliably balanced even in a state where the heating load is greater than the cooling load.

According to the present embodiment, the refrigerant flowing into the auxiliary heat exchanger 1 can be reliably condensed by the flow rate regulating valve adjustment unit 43 , and the heat exchange amount of the auxiliary heat exchanger 1 can be ensured. In this way, even in a state where the heating load is smaller than the cooling load, the heat balance of the refrigerant circuit 10 can be reliably brought into balance.

-Modification 1 of Embodiment-

Modification 1 of the embodiment shown in FIG. 6 is different from the above-mentioned embodiment in that in Modification 1, a switching mechanism 51 for switching the flow path of the refrigerant in the refrigerant circuit 10 is provided. 52 and a switching mechanism operating part (not shown) for operating the switching mechanisms 51, 52. Only the differences will be described below, and the same parts as those in the above embodiment will not be described again.

In the refrigerant circuit 10 of Modification 1, an auxiliary pipe 50 connecting the branch pipe 3 a and the fourth refrigerant pipe 9 is provided. The auxiliary pipeline 50 is provided with a first on-off valve 51 , and a second on-off valve 52 is installed near the connecting pipeline 4 on the side of the branch pipe 3 a close to the compressor.

These on-off valves 51, 52 constitute the switching mechanisms 51, 52 described above.

In addition, the first state of the above-mentioned switching mechanism 51, 52 is the state that the first switch valve 51 is closed and the second switch valve 52 is open; the second state of the above-mentioned switching mechanism 51, 52 is that the first switch valve 51 is open and the second switch valve is open. Valve 52 is closed.

The heat pump in Modification 1 is configured not only to be able to perform the above-mentioned four operations (overheating operation, overcooling operation, heating operation alone, and cooling operation only) by using the first and second on-off valves 51 and 52, but also to The second excessive heating operation is performed using the first and second on-off valves 51 and 52 . In this embodiment, the above four operations can be performed when the switching mechanisms 51 and 52 are in the first state; the second excessive heating operation can be performed when the switching mechanisms 51 and 52 are in the second state. In addition, this second excessive heating operation is an operation performed when the heating load of the heat pump is larger than the cooling load.

Here, when the heating load is greater than the cooling load and both the auxiliary heat exchanger 1 and the low-temperature heat exchanger 16 function as evaporators, the evaporation pressure of the auxiliary heat exchanger 1 and the cooling heat exchanger The smaller the pressure difference of the evaporating pressure of 16 is, the closer the suction pressure and the discharge pressure of the above-mentioned low-stage compressor 11 are, and the effect of improving the working efficiency of the heat pump brought by the two-stage compression is smaller. Moreover, if the evaporating pressure of the auxiliary heat exchanger 1 is lower than the evaporating pressure of the low-temperature heat exchanger 16, the pressure of the suction refrigerant and the discharge refrigerant pressure of the low-stage compressor 11 will be reversed, and the low-stage compression Machine 11 just doesn't work anymore. Actually, the above-mentioned low-stage compressor 11 operates to lower the pressure of the suction refrigerant, but because in this case, the pressure of the above-mentioned suction refrigerant is lower than the optimum evaporation pressure of the above-mentioned cooling heat exchanger 16, the operating efficiency of the heat pump decline.

Therefore, when the pressure difference between the evaporation pressure of the auxiliary heat exchanger 1 and the evaporation pressure of the low-temperature heat exchanger 16 is smaller than a predetermined value or the evaporation pressure of the auxiliary heat exchanger 1 is lower than the evaporation pressure of the low-temperature heat exchanger 16 , open the first on-off valve 51 and close the second on-off valve 52 (the low-stage suction state of the switching mechanisms 51 and 52). In this way, the refrigerant flows from the auxiliary heat exchanger 1 to the suction side of the low-stage compressor 11 .

In addition, in the switching mechanism operation unit, the evaporation pressure of the auxiliary heat exchanger 1 is estimated from the outdoor air temperature, and the evaporation pressure of the cooling heat exchanger 16 is estimated from the cold water temperature at the outlet of the cooling heat exchanger 16 . Therefore, when the temperature difference between the outdoor air temperature and the cold water temperature at the outlet of the cooling heat exchanger 16 is smaller than a predetermined value and the outdoor air temperature is lower than the cold water outlet temperature, the switching mechanism operation unit is switched to the low-stage suction state. .

Here, the predetermined value is set within a pressure difference range in which the effect of improving the heat pump operating efficiency by two-stage compression can be obtained.

The refrigerant circuit 10 in the case where the first on-off valve 51 is closed and the second on-off valve 52 is opened (the high-level suction state of the switching mechanisms 51 and 52 ) is substantially the same as the refrigerant circuit 10 of the above-mentioned embodiment, so description thereof will be omitted.

In this way, the switching mechanism operating unit switches between the low-stage suction state and the high-stage suction state according to the outdoor air temperature and the cold water temperature at the outlet of the cooling heat exchanger 16 . In this way, the refrigerant evaporated in the auxiliary heat exchanger 1 can be sucked into the low-stage compressor 11 or the high-stage compressor 12 as needed, so that the heat pump can always be operated efficiently.

-Modification 2 of Embodiment-

Modification 2 of the embodiment shown in FIG. 7 is different from the above-mentioned embodiment in that an economizer heat exchanger 55 is provided in this modification 2. As shown in FIG. Only the differences will be described below, and the same parts as those in the above embodiment will not be described again.

In the refrigerant circuit 10 according to Modification 2, an economizer pipe 53 that communicates the second refrigerant pipe 6 with the connecting pipe 4 on the compressor side is provided. The economizer heat exchanger 55 has a high-temperature flow path and a low-temperature flow path, and is arranged such that the high-temperature flow path communicates with the second refrigerant pipeline 6 , and the low-temperature flow path communicates with the economizer pipeline 53 . Moreover, a decompression valve 54 is provided between the above-mentioned economizer heat exchanger 55 and the part of the above-mentioned economizer pipeline 53 that is close to the side of the second refrigerant pipeline 6 .

Part of the refrigerant flowing out of the above-mentioned heating heat exchanger 13 is divided, and after being decompressed by the pressure reducing valve 54, it flows to the low-temperature flow path of the economizer heat exchanger 55, and the remaining refrigerant flows to the high-temperature flow path of the economizer heat exchanger 55. road.

In the economizer heat exchanger 55, the refrigerant in the high-temperature flow path and the refrigerant in the low-temperature flow path exchange heat, and the refrigerant in the high-temperature flow path is cooled. In this way, compared with the case where the economizer heat exchanger 55 is not provided, the subcooling degree of the refrigerant flowing from the high-temperature heat exchanger 13 to the advanced expansion valve 14 can be increased, thereby improving the efficiency of the heat pump. .

-Modification 3 of the embodiment-

Modification 3 of the embodiment shown in FIGS. 8 to 10 is different from the above-mentioned embodiment in that the refrigerant in the refrigerant circuit 10 can bypass the low-stage compressor 11 or the high-stage compressor 12 . Only the differences will be described below, and the same parts as those in the above embodiment will not be described again.

In the refrigerant circuit 10 of Modification 3, a low-stage bypass pipe (low-stage bypass passage) 18 that bypasses the above-mentioned low-stage compressor 11, and a high-stage bypass pipe (high-stage bypass passage) 18 that bypasses the above-mentioned high-stage compressor 12 are provided. access) 19. Moreover, check valves CV3 and CV4 are respectively provided on the respective bypass pipes 18 and 19 . These check valves CV3 and CV4 are provided so as to allow the refrigerant to flow from the suction side to the discharge side of the respective compressors 11 and 12 and to prohibit the refrigerant from flowing backward.

The compressor adjustment unit 41 in the controller 40 is different from the above-mentioned embodiment in that it can adjust the low-stage compressor 11 and the high-stage compressor 12 while switching between two-stage compression operation, high-stage individual compression operation, and low-stage individual compression operation. operating status. In addition, since the two-stage compression operation is the same as the operation of the excessive heating operation and the excessive cooling operation in the above-mentioned embodiment, description thereof will be omitted.

<Advanced individual compression operation>

Here, when the heating load is greater than the cooling load and both the auxiliary heat exchanger 1 and the low-temperature heat exchanger 16 function as evaporators, the evaporation pressure of the auxiliary heat exchanger 1 and the cooling heat exchanger The smaller the pressure difference of the evaporating pressure of 16 is, the closer the suction pressure and the discharge pressure of the above-mentioned low-stage compressor 11 are, and the effect of improving the working efficiency of the heat pump brought by the two-stage compression is smaller. And, if the evaporating pressure of the auxiliary heat exchanger 1 is lower than the evaporating pressure of the cooling heat exchanger 16, the pressure of the suction refrigerant and the pressure of the discharge refrigerant in the above-mentioned low-stage compressor 11 will be reversed, and the above-mentioned The low-stage compressor 11 is no longer functional.

Actually, the above-mentioned low-stage compressor 11 operates to lower the pressure of the suction refrigerant, but since the pressure of the suction refrigerant in this case is lower than the optimum evaporation pressure of the above-mentioned cooling heat exchanger 16, the operation efficiency of the heat pump decreases.

Therefore, when the pressure difference between the evaporation pressure of the auxiliary heat exchanger 1 and the evaporation pressure of the low-temperature heat exchanger 16 is smaller than a predetermined value or the evaporation pressure of the auxiliary heat exchanger 1 is lower than the evaporation pressure of the low-temperature heat exchanger 16 At this time, the above-mentioned compressor regulator 41 switches from the two-stage compression operation to the high-level single compression operation. In this high-stage individual compression operation, the above-mentioned low-stage compressor 11 is stopped, and only the above-mentioned high-stage compressor 12 is started. Since the above-mentioned low-stage compressor 11 stops, the refrigerant evaporated in the above-mentioned cooling heat exchanger 16 passes through the above-mentioned low-stage bypass pipe 18, and is sucked together with the refrigerant evaporated in the above-mentioned auxiliary heat exchanger 1. The above-mentioned advanced compressor 12 .

In Modification 3 of the present embodiment, the evaporation pressure of the auxiliary heat exchanger 1 is estimated from the outdoor air temperature, and the evaporation pressure of the cooling heat exchanger 16 is estimated from the temperature of cold water at the outlet of the cooling heat exchanger 16. . Therefore, when the temperature difference between the outdoor air temperature and the cold water temperature at the outlet of the cooling heat exchanger 16 is less than a predetermined value or when the outdoor air temperature is lower than the cold water outlet temperature, the compressor regulator 41 switches to the high-level independent Compression runs. Here, the predetermined value is set within a pressure difference range in which the effect of improving the heat pump operating efficiency by two-stage compression can be obtained.

In this high-level individual compression operation, the low-stage compressor 11 must be stopped, so the temperature of the cold water outlet of the cooling heat exchanger 16 cannot be controlled by adjusting the rotation speed of the low-stage compressor 11 . Under the high-stage single-compression operation, the temperature of the cold water outlet is controlled by adjusting the opening degree of the above-mentioned low-stage expansion valve 15 . In addition, the method of controlling the temperature of the warm water at the outlet of the heating heat exchanger 13 is the same as the above-mentioned embodiment, by adjusting the rotation speed of the above-mentioned high-level compressor 12 .

This allows the heat pump to operate with two-stage compression or single-stage compression as required, thus enabling the heat pump to always operate at high efficiency.

<Low level individual compression operation>

When the heating load is smaller than the cooling load and both the auxiliary heat exchanger 1 and the heating heat exchanger 13 function as condensers, the condensation pressure of the auxiliary heat exchanger 1 and the heating heat exchanger 13 The smaller the pressure difference of the condensing pressure, the closer the suction pressure and discharge pressure of the above-mentioned advanced compressor 12 are, and the smaller the effect of improving the working efficiency of the heat pump brought by the two-stage compression is. And, if the condensing pressure of the auxiliary heat exchanger 1 is higher than the condensing pressure of the heating heat exchanger 13, the pressure of the suction refrigerant in the above-mentioned high-level compressor 12 and the pressure of the discharge refrigerant will be reversed, and the above-mentioned The advanced compressor 12 is no longer functional.

Actually, the above-mentioned high-level compressor 12 operates to increase the pressure of the discharged refrigerant, but since the pressure of the discharged refrigerant in this case is higher than the optimum condensation pressure of the above-mentioned heating heat exchanger 13, the operating efficiency of the heat pump decline.

Therefore, when the pressure difference between the condensation pressure of the auxiliary heat exchanger 1 and the condensation pressure of the heating heat exchanger 13 is smaller than a predetermined value or the condensation pressure of the auxiliary heat exchanger 1 is condensed in the heating heat exchanger 13 When the pressure is higher than that, the above-mentioned compressor regulator 41 switches from the two-stage compression operation to the low-stage single compression operation. In this low-stage individual compression operation, the above-mentioned high-stage compressor 12 is stopped, and only the above-mentioned low-stage compressor 11 is started. Since the high-stage compressor 12 is stopped, the refrigerant discharged from the low-stage compressor 11 is diverted and flows into the auxiliary heat exchanger 1 and the high-stage bypass pipe 19 .

In addition, in this embodiment, the condensation pressure of the said heating heat exchanger 13 is estimated from the hot water outlet temperature. Therefore, when the temperature difference between the outdoor air temperature and the hot water outlet temperature is smaller than a predetermined value or when the outdoor air temperature is higher than the hot water outlet temperature, the compressor regulator 41 switches to low-stage individual compression operation. Here, the predetermined value is set within a temperature difference range converted from a pressure difference in which the effect of improving the heat pump operating efficiency by two-stage compression can be obtained.

In this low-stage individual compression operation, the high-stage compressor 12 must be stopped, so the temperature of the hot water outlet of the heating heat exchanger 13 cannot be controlled by adjusting the rotation speed of the high-stage compressor 12 . Under the low-stage single compression operation, the temperature of the warm water outlet is controlled by adjusting the opening degree of the above-mentioned high-stage expansion valve 14 . In addition, the method of controlling the temperature of the cold water at the outlet of the cooling heat exchanger 16 is performed by adjusting the rotation speed of the low-stage compressor 11 as in the above-mentioned embodiment.

This allows the heat pump to operate with two-stage compression or single-stage compression as required, thus enabling the heat pump to always operate at high efficiency.

-Modification 4 of Embodiment-

Modification 4 of the embodiment shown in FIG. 12 is different from the above-mentioned embodiment in that it can be switched to the above-mentioned overheating operation, overcooling operation, individual heating operation, individual cooling operation, second overheating operation, High-level individual compression operation and low-level individual compression operation all operate. Only the differences will be described below, and the same parts as those in the above embodiment will not be described again.

In the case of the refrigerant circuit 10 of Modification 4, a high-stage bypass pipe (high-stage bypass passage) 19 that bypasses the above-mentioned high-stage compressor 12 is provided in the refrigerant circuit 10 of Modification 1 (see FIG. 6 ). , and a check valve CV3 is provided on the high-level bypass pipe 19, the check valve CV3 allows the refrigerant to flow from the suction side to the discharge side of the high-level compressor 12, and prohibits the reverse flow of the refrigerant.

Here, when the high-stage individual compression operation is performed, the above-mentioned low-stage compressor 11 is stopped, and the first and second on-off valves 51 and 52 are fully opened. In this way, the refrigerant evaporated in the cooling-side heat exchanger 16 passes through the auxiliary pipe 50 and merges with the refrigerant evaporated in the auxiliary heat exchanger 1 , and the merged refrigerant is sucked into the high-stage compressor 12 . In addition, operations other than the high-level individual compression operation are the same as those described above, and thus description thereof will be omitted.

In this way, the operation of the heat pump can be switched as needed, so that the heat pump can always be operated with high efficiency.

(Other implementations)

The following structures can be employed in the above-described embodiments.

In this embodiment, the degree of superheating or the degree of subcooling of the refrigerant circuit 10 is controlled in the flow regulating valve adjustment unit 43 based on the determination signal of the load determination unit 42 , but the present invention is not limited thereto. For example, on the branch pipe 3a branched from the connecting pipe 4 on the side of the compressor or the branch pipe 3b branched from the connecting pipe 7 on the side of the expansion valve, a detection part for detecting the flow direction of the refrigerant is provided, and according to the It is also possible to control the degree of superheat or the degree of subcooling of the refrigerant circuit 10 by the detection signal of the detection unit.

That is, when the detection unit detects that the refrigerant flows from the side of the expansion valve of the auxiliary heat exchanger 1 to the side of the compressor, the degree of superheat is controlled by the adjustment unit 43 of the flow control valve; When it is detected that the refrigerant flows from the compressor side of the auxiliary heat exchanger 1 to the expansion valve side, the degree of subcooling is controlled by the flow regulating valve regulating unit 43 . In this way, the control performed by the flow regulating valve regulating part 43 is very reliable.

In this embodiment, the evaporation pressure/condensation pressure of the auxiliary heat exchanger 1 is estimated from the outdoor air temperature; the evaporation pressure of the cooling heat exchanger 16 is estimated from the cold water outlet temperature; Heating with heat exchanger 13 of condensing pressure. However, it is not limited thereto, for example, these pressures can be directly detected by a pressure sensor.

The temperature of the refrigerant passing through these heat exchangers 1, 13, and 16 may be detected by a temperature sensor, and the pressure may be estimated from the detected value. Also in this case, the same effect as the present invention can be obtained.

In addition, the above-mentioned embodiment is an example which is preferable in nature, but is not intended to limit the present invention, the object of application of the present invention, or the range of its use.

-Industrial Applicability-

In summary, the present invention is useful for heat pumps, especially heat pumps comprising a refrigerant circuit capable of handling both hot and cold heat.

-Symbol Description-

1 auxiliary heat exchanger

2 flow regulating valve (flow regulating mechanism)

10 refrigerant circuit

11 low-level compressor (low-level compression mechanism)

12 advanced compressor (advanced compression mechanism)

13 Heat exchanger for heating (high temperature heat exchanger)

14 Advanced Expansion Valve (Advanced Expansion Mechanism)

15 low-level expansion valve (low-level expansion mechanism)

16 Cooling heat exchanger (low temperature heat exchanger)

17 air supply fan

21 Advanced Expansion Valve Temperature Sensor

22 cooling heat exchange temperature sensor

23 The first auxiliary heat exchange temperature sensor

24 Second auxiliary heat exchange temperature sensor

25 warm water temperature sensor

26 cold water temperature sensor

30 warm water circuit

31 warm water pump

32 warm water tank

33 cold water circuit

34 cold water pump

35 cold water tank

40 controller

41 Compressor adjustment part (compression mechanism adjustment part)

42 Load judgment department

43 Flow regulating valve regulating part (flow regulating mechanism regulating part)

44 Advanced Expansion Valve Adjustment Department (Advanced Expansion Mechanism Adjustment Department)

45 Low-level expansion valve adjustment part (low-level expansion mechanism adjustment part)

Claims (6)

1. A heat pump, characterized in that it comprises a refrigerant circuit (10), an auxiliary heat exchanger (1), a compression mechanism regulator (41) and a switching mechanism (51, 52), The low-stage compression mechanism (11), high-stage compression mechanism (12), high-temperature heat exchanger (13), high-stage expansion mechanism (14), low-stage expansion mechanism (15) and low-temperature heat exchanger (16) are connected in sequence by refrigerant passages To form a refrigerant circuit (10), the refrigerant releases heat to the high-temperature fluid in the above-mentioned high-temperature heat exchanger (13), and the refrigerant absorbs heat from the low-temperature fluid in the above-mentioned low-temperature heat exchanger (16) and evaporates, thereby A refrigeration cycle can be carried out in the refrigerant circuit (10), The above-mentioned auxiliary heat exchanger (1) is connected in the above-mentioned refrigerant circuit (10), ensuring that the refrigerant passage between the above-mentioned low-stage compression mechanism (11) and the above-mentioned high-stage compression mechanism (12) is connected with the above-mentioned low-stage expansion mechanism (15) communicate with the refrigerant passage between the above-mentioned high-level expansion mechanism (14), so that the refrigerant in the above-mentioned refrigerant circuit (10) and the heat source fluid perform heat exchange in the above-mentioned auxiliary heat exchanger (1), The compression mechanism regulator (41) adjusts the working capacity of the high-stage compression mechanism (12) according to the heating load of the high-temperature heat exchanger (13), and adjusts the working capacity of the low-stage compression mechanism (12) according to the cooling load of the low-temperature heat exchanger (16). 11) Working capacity, The above-mentioned switching mechanism (51, 52) can switch between the low-level suction state and the high-level suction state, The above-mentioned low-level suction state is that when the above-mentioned heating load is greater than the above-mentioned cooling load, and the above-mentioned auxiliary heat exchanger (1) and the above-mentioned low-temperature heat exchanger (16) both function as evaporators, when the above-mentioned auxiliary heat exchanger (1) ) and the evaporation pressure of the above-mentioned low-temperature heat exchanger (16) is less than a predetermined value or when the evaporation pressure of the above-mentioned auxiliary heat exchanger (1) is below the evaporation pressure of the above-mentioned low-temperature heat exchanger (16), directing the refrigerant flowing out of the above-mentioned auxiliary heat exchanger (1) to the suction side of the above-mentioned low-stage compression mechanism (11), The above-mentioned high-level suction state is when the above-mentioned heating load is greater than the above-mentioned cooling load, and the above-mentioned auxiliary heat exchanger (1) and the above-mentioned low-temperature heat exchanger (16) both function as evaporators, when the above-mentioned pressure difference is more than a predetermined value And when the evaporation pressure of the above-mentioned auxiliary heat exchanger (1) is higher than the evaporation pressure of the above-mentioned low-temperature heat exchanger (16), the refrigerant flowing out of the above-mentioned auxiliary heat exchanger (1) is guided to the above-mentioned high-level compression mechanism (12). Suction side. 2. The heat pump according to claim 1, characterized in that: the heat pump comprises an economizer pipeline (53), a decompression mechanism (54) and an economizer heat exchanger (55), The above-mentioned economizer pipeline (53) is separated from the refrigerant pipeline between the above-mentioned high-temperature heat exchanger (13) and the above-mentioned high-level expansion mechanism (14), and is connected with the above-mentioned low-level compression mechanism (11) and the above-mentioned high-level compression mechanism (12). The refrigerant pipes between the The above-mentioned decompression mechanism (54) decompresses the refrigerant in the above-mentioned economizer pipeline (53), The above-mentioned economizer heat exchanger (55) allows the refrigerant in the above-mentioned economizer pipe (53) decompressed by the above-mentioned decompression mechanism (54) to flow from the above-mentioned high-temperature heat exchanger (13) to the above-mentioned advanced expansion mechanism (14 ) high-pressure refrigerant for heat exchange. 3. The heat pump according to claim 1 or 2, characterized in that the heat pump comprises a flow regulating mechanism (2) and a regulating part (43) of the flow regulating mechanism, The above-mentioned flow regulating mechanism (2) regulates the flow of the refrigerant flowing through the above-mentioned auxiliary heat exchanger (1), When the heating load is greater than the cooling load, the flow regulating mechanism regulator (43) adjusts the flow regulating mechanism (2) so that the degree of superheat of the refrigerant flowing out of the auxiliary heat exchanger (1) reach the specified value. 4. The heat pump according to claim 1 or 2, characterized in that the heat pump comprises a flow regulating mechanism (2) and a regulating part (43) of the flow regulating mechanism, The above-mentioned flow regulating mechanism (2) regulates the flow of the refrigerant flowing through the above-mentioned auxiliary heat exchanger (1), When the heating load is smaller than the cooling load, the flow regulating mechanism regulator (43) regulates the flow regulating mechanism (2) so that the supercooling of the refrigerant flowing out of the auxiliary heat exchanger (1) reached the specified value. 5. The heat pump according to claim 1 or 2, characterized in that the heat pump comprises an advanced expansion mechanism adjustment part (44), When the heating load is greater than the cooling load, the high-level expansion mechanism regulator (44) sets the high-level expansion mechanism (14) to fully open. 6. The heat pump according to claim 1 or 2, characterized in that the heat pump comprises an advanced expansion mechanism adjustment part (44), When the heating load is smaller than the cooling load, the high-level expansion mechanism regulator (44) adjusts the high-level expansion mechanism (14) so that the refrigerant temperature at the outlet of the high-level expansion mechanism (14) reaches the auxiliary The temperature between the temperature of the refrigerant at the outlet of the heat exchanger (1) and the temperature of the refrigerant at the outlet of the above-mentioned low-temperature heat exchanger (16).