Heat pump system

Abstract

The utility model relates to a heat pump system. The heat pump system comprises a flash tank which is provided with a first input pipe, a first output pipe and an air supply outlet pipe. In the flash tank, the distance between the end part of the first input pipe and the bottom of the flash tank is greater than that between the end part of the first output pipe and the bottom of the flash tank, and the end part of the air supply outlet pipe is arranged at the top of the flash tank; the flow path switching device is provided with a second output pipe and a second input pipe; the second output pipe is connected with the first input pipe, and the first output pipe is connected with the second input pipe; the compressor is provided with an air supply inlet; the air supply outlet pipe is connected with the air supply inlet; the refrigerant inlet and outlet ends of the first heat exchanger are connected with the compressor and the flow path switching device respectively; and the refrigerant inlet and outlet ends of the second heat exchanger are connected with the compressor and the flow path switching device correspondingly. According to the heat pump system, gaseous refrigerants entering the heat exchanger serving as the evaporator are reduced to the maximum extent, and the system performance is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of heat pumps, in particular to a heat pump system. Background Art

[0002] During the operation of the traditional air source heat pump system, especially in a low temperature environment, the evaporation temperature of the heat pump will decrease, which will lead to problems such as increased compression ratio of the compressor, reduced volumetric efficiency, and excessively high exhaust temperature, which will eventually reduce the performance of the heat pump. The air replenishment and enthalpy increase technology can effectively increase the heating capacity of the heat pump in a low temperature environment, reduce the exhaust temperature, and make the unit operate normally and stably. The flash tank is one of the commonly used equipment for air replenishment and enthalpy increase technology. In a heat pump system equipped with a flash tank for air replenishment and enthalpy increase, the circulation process of the refrigerant is: the high-temperature and high-pressure gaseous refrigerant is output from the exhaust port of the compressor to the condenser for condensation and heat release, and the condensed refrigerant enters the flash tank in the form of a gas-liquid mixture, and part of the liquid refrigerant entering the flash evaporator will flash into a gaseous state, of which the gaseous refrigerant is sprayed into the auxiliary air intake port of the compressor for air replenishment and enthalpy increase, and the liquid refrigerant enters the evaporator for evaporation and heat absorption, and evaporates into a gaseous refrigerant and enters the compressor for compression. The evaporator generally uses a fin heat exchanger to increase the heat transfer area. The fin heat exchanger is composed of multiple refrigerant pipes that are evenly arranged and interconnected. However, the evaporator in the heat pump system that uses a flash tank often has uneven distribution of refrigerant pipes in the fin heat exchanger, which affects the evaporation performance of the evaporator, reduces the amount of gas entering the compressor from the evaporator, and thus affects the performance of the entire heat pump system. Utility Model Content

[0003] Based on this, the purpose of the utility model is to provide a heat pump system, by designing the position and structure of the first input pipe, the first output pipe and the air supply outlet pipe of the flash tank, and at the same time designing the refrigerant pipeline in the flow switching device for switching between cooling and heating modes, so that no matter whether the system is in heating mode or cooling mode, the refrigerant through the heat exchanger acting as a condenser always enters the flash tank from the first input pipe, and the liquid refrigerant output from the first output pipe is always transported to the heat exchanger acting as an evaporator, so as to minimize the entry of gaseous refrigerant into the heat exchanger acting as an evaporator and improve system performance.

[0004] A heat pump system, comprising:

[0005] A flash tank is provided with a first input pipe, a first output pipe and a gas supplement outlet pipe; inside the flash tank, the distance between the end of the first input pipe and the bottom of the flash tank is higher than the distance between the end of the first output pipe and the bottom of the flash tank, and the end of the gas supplement outlet pipe is arranged at the top of the flash tank;

[0006] The flow path switching device is provided with a second output pipe and a second input pipe; the second output pipe is connected to the first input pipe, and the first output pipe is connected to the second input pipe;

[0007] The compressor is provided with an air supply inlet; the air supply outlet pipe is connected to the air supply inlet;

[0008] A first heat exchanger, the two ends of which are connected to the compressor and the flow path switching device respectively;

[0009] The second heat exchanger has two ends of the refrigerant inlet and outlet connected to the compressor and the flow path switching device respectively.

[0010] Further, the flow path switching device is provided with a first three-way reversing valve and a second three-way reversing valve;

[0011] The first three-way reversing valve is provided with a heating flow path inlet, a cooling flow path inlet and a refrigerant outlet, and the refrigerant outlet is connected to the first input pipe through the second output pipe;

[0012] The second three-way reversing valve is provided with a heating flow path outlet, a cooling flow path outlet and a refrigerant inlet, and the refrigerant inlet is connected to the first output pipe through the second input pipe;

[0013] In the heating mode, the refrigerant flows from the first heat exchanger through the heating flow path inlet and the refrigerant inlet in sequence into the flash tank, and then flows through the refrigerant inlet and the heating flow path outlet in sequence into the second heat exchanger;

[0014] In the cooling mode, the refrigerant flows from the second heat exchanger through the refrigeration flow path inlet and the refrigerant inlet in sequence into the flash tank, and then flows through the refrigerant inlet and the refrigeration flow path outlet in sequence into the first heat exchanger.

[0015] Further, the flow path switching device is provided with a first heating flow path conduction valve, a second heating flow path conduction valve, a first cooling flow path conduction valve and a second cooling flow path conduction valve;

[0016] In the heating mode, the refrigerant flows from the first heat exchanger through the first heating flow path conduction valve into the flash tank, and flows through the second heating flow path conduction valve into the second heat exchanger;

[0017] In the cooling mode, the refrigerant flows from the second heat exchanger through the first refrigeration flow path conducting valve into the flash tank, and flows through the second refrigeration flow path conducting valve into the first heat exchanger.

[0018] Further, the end of the first input pipe located at the flash tank is higher than the refrigerant liquid level in the flash tank;

[0019] The first output pipe is located at the end of the flash tank and extends to the bottom area of ​​the flash tank, and is set at a distance from the bottom surface of the flash tank.

[0020] Furthermore, the first input pipe includes a first through pipe and a plurality of second through pipes that can move up and down;

[0021] The first through pipe passes through and is fixedly connected to the tank top of the flash tank, and a plurality of second through pipes are sleeved with each other. One end of the sleeved second through pipe is sleeved on one end of the first through pipe located at the flash tank.

[0022] Furthermore, a liquid level detector is fixedly provided at the end of the first input pipe located at the flash tank, so that the first input pipe moves up and down according to the refrigerant liquid level detected by the liquid level detector.

[0023] Furthermore, a first throttle valve is provided on the pipeline connecting the flow path switching device and the first heat exchanger;

[0024] A second throttle valve is provided on the pipeline connecting the flow path switching device and the second heat exchanger.

[0025] Furthermore, a first gas-liquid separator assembly is provided on the pipeline connecting the first heat exchanger and the compressor;

[0026] A second gas-liquid separator assembly is arranged on the pipeline connecting the second heat exchanger and the compressor.

[0027] Furthermore, the flow path switching device is provided with a heating refrigerant outlet pipe, a cooling refrigerant outlet pipe and a plurality of microbubble exhaust valves;

[0028] The microbubble exhaust valve is arranged on the pipelines of the heating refrigerant outlet pipe and the cooling refrigerant outlet pipe.

[0029] Furthermore, a one-way solenoid valve is provided on the pipeline between the air supply outlet pipe and the air supply inlet, and the conducting direction of the one-way solenoid valve is the flow direction from the air supply outlet pipe to the air supply inlet.

[0030] The beneficial effects of the utility model are:

[0031] (1) By designing the position and structure of the first input pipe, the first output pipe and the air supply outlet pipe of the flash tank, and designing the refrigerant pipeline in the flow path switching device for switching between cooling and heating modes, the system is ensured that no matter whether it is in heating mode or cooling mode, the refrigerant of the heat exchanger serving as the condenser always enters the flash tank from the first input pipe, and the liquid refrigerant output from the first output pipe is always delivered to the heat exchanger serving as the evaporator, so as to minimize the gaseous refrigerant from entering the heat exchanger serving as the evaporator, thereby improving the system performance;

[0032] (2) By simultaneously setting a throttle valve between the first heat exchanger and the flash tank, and between the second heat exchanger and the flash tank, the high-temperature and high-pressure refrigerant after condensation can be cooled and depressurized in both the cooling and heating modes, and enter the flash tank to flash into a gaseous refrigerant, thereby providing the compressor with sufficient medium-pressure gaseous refrigerant for air replenishment and enthalpy increase, so as to reduce the compression ratio of the compressor;

[0033] (3) By simultaneously providing a gas-liquid separator between the first heat exchanger and the compressor, and between the second heat exchanger and the compressor, the low-pressure refrigerant after evaporation can be separated into gas and liquid in both cooling and heating modes, so as to prevent the liquid refrigerant from entering the compressor and affecting the performance and life of the compressor;

[0034] (4) By setting a microbubble exhaust valve, the gaseous refrigerant input into the evaporator can be further discharged, and impurities and dirt entering the system can be removed.

[0035] (5) A one-way solenoid valve is provided between the air supply outlet pipe of the flash tank and the air supply inlet of the compressor so as to control whether the gaseous refrigerant in the flash tank enters the compressor for air supply and enthalpy increase according to actual needs.

[0036] In order to better understand and implement the present invention, the present invention is described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 A schematic diagram of a heat pump system provided in an embodiment of the present application;

[0038] Figure 2 A schematic diagram of the flash tank structure provided in an embodiment of the present application;

[0039] Figure 3 A schematic diagram of a heat pump system provided in Example 1 of the present application;

[0040] FIG4( a ) is a schematic diagram of the refrigerant flow direction of the heat pump system in heating mode provided in Example 1 of the present application;

[0041] FIG4( b ) is a schematic diagram of the refrigerant flow direction of the heat pump system provided in the first embodiment of the present application in the cooling mode;

[0042] Figure 5 A schematic diagram of a heat pump system provided in Example 2 of the present application;

[0043] FIG6( a ) is a schematic diagram of the refrigerant flow direction of the heat pump system in heating mode provided in Embodiment 2 of the present application;

[0044] FIG6( b ) is a schematic diagram of the refrigerant flow direction of the heat pump system in cooling mode provided in Example 2 of the present application;

[0045] FIG7( a ) is a schematic diagram of a heat pump system provided in a further embodiment of the first embodiment of the present application;

[0046] FIG7( b ) is a schematic diagram of a heat pump system provided in a further embodiment of the first embodiment of the present application.

[0047] In the figure: 10-flash tank; 11-first input pipe; 111-first through pipe; 112-second through pipe; 12-first output pipe; 13-air supply outlet pipe; 14-liquid level detector; 20-flow path switching device; 211-second output pipe; 212-second input pipe; 221-heating refrigerant inlet pipe; 222-heating refrigerant outlet pipe; 223-refrigeration refrigerant outlet pipe; 224-refrigeration refrigerant inlet pipe; 231-first three-way reversing valve; 2311-refrigerant outlet; 2312-heating flow inlet; 2313-refrigeration flow inlet; 232-second three-way reversing valve; 2321-refrigerant inlet; 2322-heating flow outlet; 2323-refrigeration flow outlet; 241-first heating flow conduction valve; 242 -Second heating flow path conduction valve; 243-First refrigeration flow path conduction valve; 244-Second refrigeration flow path conduction valve; 25-Microbubble exhaust valve; 30-Compressor; 31-Air supply inlet; 32-First air vent; 33-Second air vent; 40-First heat exchanger; 41-First connecting pipe; 42-Second connecting pipe; 411-First connecting branch pipe; 50-Second heat exchanger; 51-Third connecting pipe; 52-Fourth connecting pipe; 521-Fourth connecting branch pipe; 61-First throttle valve; 62-Second throttle valve; 63-One-way solenoid valve; 71-First gas-liquid separator; 711-First one-way valve; 712-Second one-way valve; 72-Second gas-liquid separator; 721-Third one-way valve; 722-Fourth one-way valve. DETAILED DESCRIPTION

[0048] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0049] In the description of the present invention, it should be noted that the terms "vertical direction", "upper", "lower", "horizontal" and the like indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, "first", "second", "third", and "fourth" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0050] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection, a mechanical connection, an electrical connection, a direct connection, or a connection through an intermediate medium, or the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0051] The existing heat pump system is connected in sequence by a refrigerant pipeline with a compressor, a first heat exchanger, a flash tank and a second heat exchanger. The flash tank is provided with a refrigerant input pipe, a refrigerant output pipe and an air supply output pipe, and the refrigerant input pipe and the refrigerant output pipe are both arranged at the same height. In the heating mode, the first heat exchanger acts as a condenser, and the second heat exchanger acts as an evaporator. The condensed refrigerant enters the flash tank from the refrigerant input pipe and is output from the refrigerant output pipe to the second heat exchanger for evaporation and heat absorption. In the cooling mode, the second heat exchanger acts as a condenser, and the first heat exchanger acts as an evaporator. The condensed refrigerant enters the flash tank from the refrigerant output pipe and is output from the refrigerant input pipe to the first heat exchanger for evaporation and heat absorption.

[0052] Aiming at the problem of uneven refrigerant liquid separation in the existing heat pump system evaporator, it is found through analysis that the refrigerant enters the flash tank and is a mixed refrigerant of liquid and gas after flash evaporation. When the refrigerant input pipe and the refrigerant output pipe are set at the same height, part of the gaseous refrigerant entering the flash tank does not have time to rise and enters the refrigerant output pipe with the liquid refrigerant, and then enters the evaporator together for evaporation, and the gaseous refrigerant mixed in the liquid refrigerant is bound to affect the uniformity of the liquid refrigerant and the system performance. Moreover, when the cooling and heating modes are switched, the refrigerant output pipe and the refrigerant input pipe also switch between the input and output functions. Therefore, it is urgent to design a flash tank that can completely separate the gaseous and liquid refrigerants as much as possible, and after complete separation, it is also necessary to ensure that when switching between the cooling and heating modes, the refrigerant input pipe and the refrigerant output pipe can always serve as the refrigerant input end after condensation and the output end of the liquid refrigerant after separation, so as to minimize the gaseous refrigerant entering the evaporator with the liquid refrigerant and affecting the distribution uniformity of the liquid refrigerant.

[0053] Based on this, the utility model provides a heat pump system, by designing the position and structure of the first input pipe, the first output pipe and the air supply outlet pipe of the flash tank, and at the same time designing the refrigerant pipeline in the flow switching device for switching between cooling and heating modes, so that no matter whether the system is in heating mode or cooling mode, the refrigerant of the heat exchanger acting as a condenser always enters the flash tank from the first input pipe, and the liquid refrigerant output from the first output pipe is always transported to the heat exchanger acting as an evaporator, so as to minimize the entry of gaseous refrigerant into the heat exchanger acting as an evaporator and improve system performance.

[0054] Please also see Figure 1 and Figure 2 The heat pump system provided in the embodiment of the present application is provided with a plurality of refrigerant pipelines, including a flash tank 10, a flow path switching device 20, a compressor 30, a first heat exchanger 40, and a second heat exchanger 50 connected by the refrigerant pipeline, and the refrigerant in the refrigerant pipeline flows through the compressor 30, the first heat exchanger 40, the flow path switching device 20, the flash tank 10, the flow path switching device 20, the second heat exchanger 50, and the compressor 30 in sequence.

[0055] Specifically, the flash tank 10 is provided with a first input pipe 11, a first output pipe 12 and an air supply outlet pipe 13. One ends of the first input pipe 11, the first output pipe 12 and the air supply outlet pipe 13 extend into the interior of the flash tank 10 for inputting and outputting the refrigerant into and out of the flash tank 10, and the other ends are arranged outside the flash tank 10 for connecting to an external refrigerant pipeline.

[0056] Since the density of liquid refrigerant is relatively large and the density of gaseous refrigerant is relatively small, in the flash tank 10, the gaseous refrigerant will rise to the top of the flash tank 10, and the liquid refrigerant will sink to the bottom of the flash tank 10, thereby achieving gas-liquid separation. The condensed refrigerant enters the interior of the flash tank 10 from the first input pipe 11. At this time, the refrigerant is a gas-liquid mixture containing a small amount of gaseous refrigerant. In order to allow the gaseous refrigerant enough time to rise to the top of the flash tank 10 and the liquid refrigerant enough time to sink to the bottom of the flash tank 10, so as to avoid the gaseous refrigerant being output from the first output pipe 12 together with the liquid refrigerant, the distance between the end of the first input pipe 11 located inside the flash tank 10 and the bottom of the flash tank 10 is higher than the distance between the end of the first output pipe 12 located inside the flash tank 10 and the bottom of the flash tank 10. The end of the air supply outlet pipe 13 located inside the flash tank 10 is arranged at the top of the flash tank 10, which can prevent the liquid refrigerant from entering the compressor 30 and affecting the performance.

[0057] Preferably, in order to further reduce the gaseous refrigerant in the liquid refrigerant output by the first output pipe 12, the end of the first output pipe 12 located inside the flash tank 10 extends to the bottom area of ​​the flash tank 10, and the end of the first input pipe 11 located inside the flash tank 10 is higher than the refrigerant liquid level of the flash tank 10. It should be noted that the end of the first output pipe 12 located inside the flash tank 10 cannot abut against the bottom surface of the flash tank 10, and needs to be set at a certain distance from the bottom surface of the flash tank 10 to reserve a certain space for the liquid refrigerant to enter the first output pipe 12.

[0058] In actual operation, the refrigerant liquid level in the flash tank 10 changes at any time. In order to ensure that the end of the first input pipe 11 located inside the flash tank 10 is always higher than the refrigerant liquid level in the flash tank 10, as a further step, the first input pipe 11 is set as a length-adjustable through-tube structure, specifically including a first through-tube 111 and a plurality of second through-tubes 112 that can move up and down. The first through-tube 111 passes through and is fixed to the tank top of the flash tank 10, with one end located outside the flash tank 10 and the other end located inside the flash tank 10; a plurality of second through-tubes 112 are mutually sleeved, and one end of the sleeved second through-tubes 112 is sleeved on one end of the first through-tube 111 located in the flash tank 10 and is mutually conductively connected. It can be understood that in order to prevent liquid refrigerant from entering the air supply outlet pipe 13, the end of the first input pipe 11 located in the flash tank 10 must also be ensured not to be lower than the end of the air supply outlet pipe 13.

[0059] Furthermore, in order to allow the first input pipe 11 to automatically adjust the length of the first input pipe 11 extending into the flash tank 10 according to the height of the refrigerant liquid level, a liquid level detector 14 is fixedly provided inside the flash tank 10. Preferably, the liquid level detector 14 is fixedly provided at the end of the first input pipe 11 located at the flash tank. The heat pump system is also provided with a controller (not shown), which can control the up and down movement of the second through pipe 112, and the liquid level detector 14 is connected to the controller by signal or electrical connection, preferably by signal connection. The liquid level detector 14 transmits the detected height to the controller, and the controller then controls the first input pipe 11 to adjust the upper height.

[0060] It can be understood that in the heating mode and the cooling mode, the flow direction of the high-temperature and high-pressure gaseous refrigerant when it is circulated after being output from the compressor 30 is opposite. When the first input pipe 11 and the first output pipe 12 are set high and low, the gas-liquid mixed refrigerant must always enter the flash tank 10 from the first input pipe 11, and the separated liquid refrigerant must always be output from the first output pipe 12 to the first heat exchanger 40 or the second heat exchanger 50 acting as the evaporator, so as to ensure that relatively pure liquid refrigerant can enter the evaporator. Therefore, the flow switching device 20 is provided with a second output pipe 211 and a second input pipe 212. The second output pipe 211 is conductively connected to the first input pipe 11, and is used to input the refrigerant condensed by the first heat exchanger 40 or the second heat exchanger 50 acting as a condenser into the flash tank 10 through the refrigerant pipeline in the flow switching device 20. The first output pipe 12 is conductively connected to the second input pipe 212, and is used to output the liquid refrigerant from the flash tank 10 to the first heat exchanger 40 or the second heat exchanger 50 acting as an evaporator for evaporation and heat absorption.

[0061] The compressor 30 is provided with an air supply inlet 31, a first air vent 32 and a second air vent 33. The air supply outlet pipe 13 is connected to the air supply inlet 31 through a refrigerant pipeline. The gaseous refrigerant enters the compressor 30 through the air supply outlet pipe 13 and the air supply inlet 31 to supply air and increase enthalpy, so as to reduce the compression ratio of the compressor 30, improve the volumetric efficiency, and avoid the problem of excessive exhaust temperature.

[0062] The two ends of the refrigerant inlet and outlet of the first heat exchanger 40 are connected to the compressor 30 and the flow path switching device 20, respectively. Specifically, a first connecting pipe 41 is provided between the first heat exchanger 40 and the compressor 30, and a second connecting pipe 42 is provided between the flow path switching device 20 and the first heat exchanger 40. One end of the first connecting pipe 41 is connected to one of the refrigerant inlet and outlet ports of the first heat exchanger 40, and the other end is connected to the first vent 32, and one end of the second connecting pipe 42 is connected to another refrigerant inlet and outlet port of the first heat exchanger 40, and the other end is connected to the flow path switching device 20.

[0063] The two ends of the refrigerant inlet and outlet of the second heat exchanger 50 are connected to the compressor 30 and the flow path switching device 20. Specifically, a third connecting pipe 51 is provided between the flow path switching device 20 and the second heat exchanger 50, and a fourth connecting pipe 52 is provided between the second heat exchanger 50 and the compressor 30. One end of the third connecting pipe 51 is connected to one of the refrigerant inlet and outlet ports of the second heat exchanger 50, and the other end is connected to the flow path switching device 20, and one end of the fourth connecting pipe 52 is connected to another refrigerant inlet and outlet port of the second heat exchanger 50, and the other end is connected to the second vent 33.

[0064] See also Figure 3 As the first embodiment of the present application, the flow path switching device 20 is provided with a plurality of inlet and outlet refrigerant pipes and a first three-way reversing valve 231 and a second three-way reversing valve 232. The plurality of inlet and outlet refrigerant pipes include a heating refrigerant inlet pipe 221, a heating refrigerant outlet pipe 222, a cooling refrigerant outlet pipe 223 and a cooling refrigerant inlet pipe 224. The first three-way reversing valve 231 is provided with a refrigerant outlet 2311, a heating flow path inlet 2312 and a cooling flow path inlet 2313. The second three-way reversing valve 232 is provided with a refrigerant inlet 2321, a heating flow path outlet 2322 and a cooling flow path outlet 2323. One end of the heating refrigerant inlet pipe 221 and the cooling refrigerant outlet pipe 223 are both connected to the end of the second connecting pipe 42 that is not connected to the first heat exchanger 40, and the other ends are respectively connected to the heating flow path inlet 2312 and the cooling flow path outlet 2323; one end of the heating refrigerant outlet pipe 222 and the cooling refrigerant inlet pipe 224 are both connected to the end of the third connecting pipe 51 that is not connected to the second heat exchanger 50, and the other ends are respectively connected to the heating flow path outlet 2322 and the cooling flow path inlet 2313; the refrigerant outlet 2311 is connected to the end of the second output pipe 211 that is not connected to the first input pipe 11, and the refrigerant inlet 2321 is connected to the end of the second input pipe 212 that is not connected to the first output pipe 12.

[0065] In this embodiment, the first three-way reversing valve 231 and the second three-way reversing valve 232 are preferably three-way reversing solenoid valves, which are communicatively connected or electrically connected to the controller, and the mutual conduction between the refrigerant outlet 2311, the heating flow path inlet 2312 and the cooling flow path inlet 2313, and the mutual conduction between the refrigerant inlet 2321, the heating flow path outlet 2322 and the cooling flow path outlet 2323 are controlled by the controller to realize the switching between the heating mode and the cooling mode. The first heat exchanger 40 is an indoor heat exchanger, and the second heat exchanger 50 is an outdoor heat exchanger. The first heat exchanger 40 can perform heat exchange with gas or liquid to obtain gas and liquid at the temperature required by the user.

[0066] Please refer to Figure 4(a). When the indoor room is in heating mode, the first heat exchanger 40 acts as a condenser and the second heat exchanger 50 acts as an evaporator. At this time, the refrigerant outlet 2311 and the heating flow inlet 2312, and the refrigerant inlet 2321 and the heating flow outlet 2322 are connected, and the heating flow inlet 2312 and the cooling flow inlet 2313, and the refrigerant inlet 2321 and the cooling flow outlet 2322 are blocked. The refrigerant circulates in the direction of the compressor 30, the first heat exchanger 40, the flash tank 10, the second heat exchanger 50, and the compressor 30 in sequence. Specifically, the high-temperature and high-pressure gaseous refrigerant after being compressed by the compressor 30 is discharged from the first vent 32, flows through the first connecting pipe 41 and enters the first heat exchanger 40, and is condensed into liquid refrigerant. Heat is emitted during the condensation process. Part of the gaseous refrigerant in the first heat exchanger 40 is not condensed into liquid refrigerant. The refrigerant flows from the first heat exchanger 40 in the form of a gas-liquid mixture, sequentially through the second connecting pipe 42, the heating refrigerant inlet pipe 221, the heating flow path inlet 2312, the refrigerant outlet 2311, the second output pipe 211, and the first input pipe 1 1 enters the flash tank 10, where gas-liquid separation is performed, and the gaseous refrigerant flows out from the gas supplement outlet 13 and is transported to the gas supplement inlet 31. The liquid refrigerant flows through the first output pipe 12, the second input pipe 212, the refrigerant inlet 2321, the heating flow path outlet 2322, the heating refrigerant outlet pipe 222, and the third connecting pipe 51 in sequence and enters the second heat exchanger 50, where it evaporates into a gaseous refrigerant, absorbing heat during the evaporation process. The low-temperature and low-pressure gaseous refrigerant flows through the fourth connecting pipe 52 and enters the compressor 30 for compression again, and the cycle continues.

[0067] Please refer to Figure 4(b). When the indoor environment is in cooling mode, the second heat exchanger 50 acts as a condenser and the first heat exchanger 40 acts as an evaporator. The refrigerant outlet 2311 and the refrigeration flow inlet 2313, and the refrigerant inlet 2321 and the refrigeration flow outlet 2323 are connected, and the refrigerant outlet 2311 and the heating flow inlet 2312, and the refrigerant inlet 2321 and the heating flow outlet 2322 are blocked. The refrigerant circulates in the flow direction of the compressor 30, the second heat exchanger 50, the flash tank 10, the first heat exchanger 40, and the compressor 30 in sequence. Specifically, the high-temperature and high-pressure gaseous refrigerant after being compressed by the compressor 30 is discharged from the second vent 33, flows through the fourth connecting pipe 52 and enters the second heat exchanger 50, and is condensed into liquid refrigerant. Heat is emitted during the condensation process. Part of the gaseous refrigerant in the second heat exchanger 50 is not condensed into liquid refrigerant. The refrigerant flows from the second heat exchanger 50 in the form of a gas-liquid mixture through the third connecting pipe 51, the refrigerant inlet pipe 224, the refrigerant flow path inlet 2313, the refrigerant outlet 2311, the second output pipe 211, and the first input pipe 1 1 enters the flash tank 10, where gas-liquid separation is performed, and the gaseous refrigerant flows out from the gas replenishment outlet 13 and is transported to the gas replenishment inlet 31. The liquid refrigerant flows through the first output pipe 12, the second input pipe 212, the refrigerant inlet 2321, the refrigeration flow path outlet 2323, the refrigeration refrigerant outlet pipe 223, and the second connecting pipe 42 in sequence and enters the first heat exchanger 40, where it evaporates into a gaseous refrigerant, absorbing heat during the evaporation process. The low-temperature and low-pressure gaseous refrigerant flows through the first connecting pipe 41 and enters the compressor 30 for compression again, and the cycle continues.

[0068] See also Figure 5 As a second embodiment of the present application, the flow path switching device 20 is provided with a first heating flow path conduction valve 241, a second heating flow path conduction valve 242, a first cooling flow path conduction valve 243, and a second cooling flow path conduction valve 244. The first heating flow path conduction valve 241 and the second heating flow path conduction valve 242 have the same conduction direction, the first cooling flow path conduction valve 243 and the second cooling flow path conduction valve 244 have the same conduction direction, and the first cooling flow path conduction valve 243 has an opposite conduction direction to the first heating flow path conduction valve 241.

[0069] One end of the heating refrigerant inlet pipe 221 is connected to the end of the second connecting pipe 42 that is not connected to the first heat exchanger 40, and the other end is connected to the end of the second output pipe 211 that is not connected to the first input pipe 11. The first heating flow path conducting valve 241 is arranged on the pipeline of the heating refrigerant inlet pipe 221, and its conducting direction is the flow direction of the refrigerant from the first heat exchanger 40 to the flash tank 10.

[0070] One end of the heating refrigerant outlet pipe 222 is connected to an end of the third connecting pipe 51 that is not connected to the second heat exchanger 50, and the other end is connected to an end of the second input pipe 212 that is not connected to the first output pipe 12. The second heating flow path conducting valve 242 is arranged on the pipeline of the heating refrigerant outlet pipe 222, and its conducting direction is the flow direction of the refrigerant from the flash tank 10 to the second heat exchanger 50.

[0071] One end of the refrigeration refrigerant outlet pipe 223 is connected to the end of the second connecting pipe 42 that is not connected to the first heat exchanger 40, and the other end is connected to the end of the second input pipe 212 that is not connected to the first output pipe 12. The first refrigeration flow circuit conducting valve 243 is arranged on the pipeline of the refrigeration refrigerant outlet pipe 223, and its conducting direction is the flow direction of the refrigerant from the flash tank 10 to the first heat exchanger 40.

[0072] One end of the refrigeration refrigerant inlet pipe 224 is connected to an end of the third connecting pipe 51 that is not connected to the second heat exchanger 50, and the other end is connected to an end of the second output pipe 211 that is not connected to the first input pipe 11. The second refrigeration flow circuit conducting valve 244 is arranged on the pipeline of the refrigeration refrigerant inlet pipe 224, and its conducting direction is the flow direction of the refrigerant from the second heat exchanger 50 to the flash tank 10.

[0073] The first heating flow circuit conduction valve 241, the second heating flow circuit conduction valve 242, the first cooling flow circuit conduction valve 243 and the second cooling flow circuit conduction valve 244 are preferably unidirectional solenoid valves, which are communicatively connected or electrically connected to the controller. The controller controls the unidirectional conduction of the first heating flow circuit conduction valve 241, the second heating flow circuit conduction valve 242, the first cooling flow circuit conduction valve 243 and the second cooling flow circuit conduction valve 244 to achieve switching between the heating mode and the cooling mode.

[0074] Please refer to FIG. 6(a). When the indoor temperature is in heating mode, the first heating flow path conduction valve 241 and the second heating flow path conduction valve 242 are turned on, and the first cooling flow path conduction valve 243 and the second cooling flow path conduction valve 244 are turned off. The refrigerant circulates in sequence along the compressor 30, the first heat exchanger 40, the flash tank 10, the second heat exchanger 50, and the compressor 30. Specifically, the high-temperature and high-pressure gaseous refrigerant after being compressed by the compressor 30 is discharged from the first vent 32, flows through the first connecting pipe 41 and enters the first heat exchanger 40, and condenses into liquid refrigerant. Heat is emitted during the condensation process. Part of the gaseous refrigerant in the first heat exchanger 40 is not condensed into liquid refrigerant. The refrigerant flows from the first heat exchanger 40 in the form of a gas-liquid mixture through the second connecting pipe 42, the heating refrigerant inlet pipe 221, the first heating flow path conduction valve 241, the second output pipe 211, the first input pipe 1 1 enters the flash tank 10, where gas-liquid separation is performed, and the gaseous refrigerant flows out from the gas supplement outlet 13 and is transported to the gas supplement inlet 31. The liquid refrigerant flows through the first output pipe 12, the second input pipe 212, the heating refrigerant outlet pipe 222, the second heating flow path conduction valve 242, and the third connecting pipe 51 in sequence and enters the second heat exchanger 50, where it evaporates into a gaseous refrigerant, absorbing heat during the evaporation process. The low-temperature and low-pressure gaseous refrigerant flows through the fourth connecting pipe 52 and enters the compressor 30 for compression again, and the cycle continues.

[0075] Please refer to FIG. 6(b). When the indoor room is in cooling mode, the first cooling flow path conduction valve 243 and the second cooling flow path conduction valve 244 are turned on, and the first heating flow path conduction valve 241 and the second heating flow path conduction valve 242 are turned off. The refrigerant circulates in sequence along the flow direction of the compressor 30, the second heat exchanger 50, the flash tank 10, the first heat exchanger 40, and the compressor 30. Specifically, the high-temperature and high-pressure gaseous refrigerant after being compressed by the compressor 30 is discharged from the second vent 33, flows through the fourth connecting pipe 52 and enters the second heat exchanger 50, and condenses into liquid refrigerant. Heat is emitted during the condensation process. Part of the gaseous refrigerant in the second heat exchanger 50 is not condensed into liquid refrigerant. The refrigerant flows from the second heat exchanger 50 in the form of a gas-liquid mixture through the third connecting pipe 51, the refrigerant inlet pipe 224, the second cooling flow path conduction valve 244, the second output pipe 211, the first input pipe 1 1 enters the flash tank 10, where gas-liquid separation is performed, and the gaseous refrigerant flows out from the gas replenishment outlet 13 and is transported to the gas replenishment inlet 31. The liquid refrigerant flows through the first output pipe 12, the second input pipe 212, the refrigeration refrigerant outlet pipe 223, the first refrigeration flow path conduction valve 243, and the second connecting pipe 42 in sequence and enters the first heat exchanger 40, where it evaporates into a gaseous refrigerant, absorbing heat during the evaporation process. The low-temperature and low-pressure gaseous refrigerant flows through the first connecting pipe 41 and enters the compressor 30 for compression again, and the cycle continues.

[0076] In the two embodiments described above, by adopting the flash tank 10 designed in the present application and combining the flow path design of the flow path switching device 20, whether in heating mode or cooling mode, the refrigerant in the form of gas-liquid mixture after condensation can enter the flash tank 10 from the first input pipe 11 for gas separation, and the liquid refrigerant is output from the first output pipe 12 to the subsequent first heat exchanger 40 or the second heat exchanger 50 acting as an evaporator for evaporation. This ensures that the amount of gaseous refrigerant of the liquid refrigerant entering the first heat exchanger 40 or the second heat exchanger 50 acting as an evaporator is always at a low level.

[0077] Since the gaseous refrigerant content of the gas-liquid mixed refrigerant after condensation is relatively small, the gaseous refrigerant content used as the compressor 30 gas supplement and enthalpy increase after entering the flash tank 10 for gas separation is relatively small, and the lower the pressure of the gaseous refrigerant used as the compressor 30 gas supplement and enthalpy increase, the more conducive to reducing the compression ratio, a first throttle valve 61 is set on the pipeline of the second connecting pipe 42, and a second throttle valve 62 is set on the pipeline of the third connecting pipe 51, and the throttle valve can be used for fluid pressure reduction. In the heating mode or the cooling mode, the refrigerant output from the first heat exchanger 40 or the second heat exchanger 50 is still in a high temperature and high pressure state, and the high temperature and high pressure refrigerant enters the flash tank 10 through the first throttle valve 61 or the second throttle valve 62. Based on the changing characteristics of the boiling point of the substance, if the refrigerant temperature is higher than the boiling point under the pressure, it will quickly boil and vaporize in the flash tank 10, and the gas obtained by flash evaporation is a medium pressure gas. By using the first throttle valve 61 or the second throttle valve 62 in conjunction with the flash tank 10, more medium-pressure gaseous refrigerant can be obtained, which is beneficial for replenishing air and increasing enthalpy of the compressor 30.

[0078] Furthermore, the flow path switching device 20 is also provided with a plurality of microbubble exhaust valves 25. The microbubble exhaust valves 25 are arranged on the pipelines of the heating refrigerant outlet pipe 222 and the cooling refrigerant outlet pipe 223. The number of microbubble exhaust valves 25 arranged on the heating refrigerant outlet pipe 222 or the cooling refrigerant outlet pipe 223 is at least one. The microbubble exhaust valve 25 can quickly remove free gas, microbubbles, and dissolved gas in the pipeline, and can continuously collect dirt in the circulating pipeline system. In order to further discharge the gaseous refrigerant output by the first output pipe 12, and remove impurities and dirt entering the system.

[0079] Since the refrigerant after passing through the first heat exchanger 40 or the second heat exchanger 50 acting as an evaporator contains a small amount of liquid refrigerant, the liquid refrigerant entering the compressor will damage it. As a further embodiment of the first and second embodiments, a first gas-liquid separator 71 is provided between the first heat exchanger 40 and the compressor 30, and a second gas-liquid separator 72 is provided between the second heat exchanger 50 and the compressor 30. Specifically, the first gas-liquid separator 71 is provided on the pipeline of the first connecting pipe 41, and the second gas-liquid separator 72 is provided on the pipeline of the fourth connecting pipe 52. When the indoor room is in heating mode, the high-temperature and high-pressure gas flowing out of the compressor 30 flows through the first gas-liquid separator 71 and enters the first heat exchanger 40; the second heat exchanger 50 acts as an evaporator, and the refrigerant passing through the second heat exchanger 50 enters the second gas-liquid separator 72 for gas-liquid separation, and the gaseous refrigerant is input into the compressor 30 from the second vent 33. When the indoor room is in cooling mode, the high-temperature and high-pressure gas flowing out of the compressor 30 flows through the second gas-liquid separator 72 and enters the second heat exchanger 50; the first heat exchanger 40 acts as an evaporator, and the refrigerant passing through the first heat exchanger 40 enters the first gas-liquid separator 71 for gas-liquid separation, and the gaseous refrigerant is input into the compressor 30 from the first air vent 32.

[0080] Please refer to FIG7 . Since the refrigerant flowing out of the compressor 30 is a high-temperature and high-pressure gaseous refrigerant, when the first heat exchanger 40 or the second heat exchanger 50 acts as a condenser, the high-temperature and high-pressure gaseous refrigerant can be directly input into the first heat exchanger 40 or the second heat exchanger 50 , and does not need to enter the first gas-liquid separator 71 or the second gas-liquid separator 72 for gas-liquid separation, which can reduce the use of the first gas-liquid separator 71 or the second gas-liquid separator 72 , thereby reducing energy consumption and extending the service life of the gas-liquid separator. In a more preferred embodiment, a first gas-liquid separator assembly is provided on the pipeline connecting the first heat exchanger 40 and the compressor 30; a second gas-liquid separator assembly is provided on the pipeline connecting the second heat exchanger 50 and the compressor 30.

[0081] Specifically, the first gas-liquid separation component includes a first gas-liquid separator 71, two first one-way valves 711 and a second one-way valve 712. The first gas-liquid separator 71 is arranged between the two first one-way valves 711, and the conducting direction of the first one-way valve 711 is the flow direction from the first heat exchanger 40 to the compressor 30; the second one-way valve 712 is arranged in parallel with the first gas-liquid separator 71 and the first one-way valve 711, and its conducting direction is opposite to the conducting direction of the first one-way valve 711. Specifically, the first gas-liquid separator 71 and the first one-way valve 711 are arranged on the pipeline of the first connecting pipe 41, a first connecting branch pipe 411 is arranged between the first heat exchanger 40 and the compressor 30, the first connecting branch pipe 411 is arranged in parallel with the first connecting pipe 41, and the second one-way valve 712 is arranged on the pipeline of the first connecting branch pipe 411.

[0082] The second gas-liquid separation component includes a second gas-liquid separator 72, two third one-way valves 721 and a fourth one-way valve 722. The second gas-liquid separator 72 is arranged between the two third one-way valves 721, and the conduction direction of the third one-way valve 721 is the flow direction from the second heat exchanger 50 to the compressor 30; the fourth one-way valve 722 is arranged in parallel with the second gas-liquid separator 72 and the third one-way valve 721, and its conduction direction is opposite to the conduction direction of the third one-way valve 721. Specifically, the second gas-liquid separator 72 and the third one-way valve 721 are arranged on the pipeline of the fourth connecting pipe 52, a fourth connecting branch pipe 521 is arranged between the second heat exchanger 50 and the compressor 30, the fourth connecting branch pipe 521 is arranged in parallel with the fourth connecting pipe 52, and the fourth one-way valve 722 is arranged on the pipeline of the fourth connecting branch pipe 521.

[0083] When the room is in heating mode, the high-temperature and high-pressure gas flowing out of the compressor 30 directly enters the first heat exchanger 40 through the second one-way valve 712, and the refrigerant passing through the second heat exchanger 50 enters the second gas-liquid separator 72 for gas-liquid separation, and the gaseous refrigerant is input into the compressor 30 from the second vent 33. When the room is in cooling mode, the high-temperature and high-pressure gas flowing out of the compressor 30 directly enters the second heat exchanger 50 through the fourth one-way valve 722, and the refrigerant passing through the first heat exchanger 40 enters the first gas-liquid separator 71 for gas-liquid separation, and the gaseous refrigerant is input into the compressor 30 from the first vent 32.

[0084] Please also see Figure 3 , Figure 5 7, as a further embodiment of the above embodiment, a one-way solenoid valve 63 is provided between the air supply outlet pipe 13 and the air supply inlet 31, and the conduction direction of the one-way solenoid valve 63 is the flow direction from the air supply outlet pipe 13 to the air supply inlet 31. The one-way solenoid valve 63 is communicatively connected or electrically connected to the controller, and by controlling the conduction and cutoff of the one-way solenoid valve 63, it is possible to control whether the gaseous refrigerant in the flash tank 10 enters the compressor 30 for air supply and enthalpy increase according to actual needs.

[0085] Compared with the prior art, the technical solution of this application has the following beneficial effects:

[0086] (1) By designing the position and structure of the first input pipe, the first output pipe and the air supply outlet pipe of the flash tank, and designing the refrigerant pipeline in the flow path switching device for switching between cooling and heating modes, the system is ensured that no matter whether it is in heating mode or cooling mode, the refrigerant of the heat exchanger serving as the condenser always enters the flash tank from the first input pipe, and the liquid refrigerant output from the first output pipe is always delivered to the heat exchanger serving as the evaporator, so as to minimize the gaseous refrigerant from entering the heat exchanger serving as the evaporator, thereby improving the system performance;

[0087] (2) By simultaneously setting a throttle valve between the first heat exchanger and the flash tank, and between the second heat exchanger and the flash tank, the high-temperature and high-pressure refrigerant after condensation can be cooled and depressurized in both the cooling and heating modes, and enter the flash tank to flash into a gaseous refrigerant, thereby providing the compressor with sufficient medium-pressure gaseous refrigerant for air replenishment and enthalpy increase, so as to reduce the compression ratio of the compressor;

[0088] (3) By simultaneously providing a gas-liquid separator between the first heat exchanger and the compressor, and between the second heat exchanger and the compressor, the low-pressure refrigerant after evaporation can be separated into gas and liquid in both cooling and heating modes, so as to prevent the liquid refrigerant from entering the compressor and affecting the performance and life of the compressor;

[0089] (4) By setting a microbubble exhaust valve, the gaseous refrigerant input into the evaporator can be further discharged, and impurities and dirt entering the system can be removed.

[0090] (5) A one-way solenoid valve is provided between the air supply outlet pipe of the flash tank and the air supply inlet of the compressor so as to control whether the gaseous refrigerant in the flash tank enters the compressor for air supply and enthalpy increase according to actual needs.

[0091] The above-mentioned embodiments only express several implementation methods of the utility model, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the utility model patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the utility model, and the utility model is also intended to include these modifications and modifications.

Claims

1. A heat pump system, characterized in that: include: A flash tank is provided with a first input pipe, a first output pipe and a gas supplement outlet pipe; inside the flash tank, the distance between the end of the first input pipe and the bottom of the flash tank is higher than the distance between the end of the first output pipe and the bottom of the flash tank, and the end of the gas supplement outlet pipe is arranged at the top of the flash tank; The flow path switching device is provided with a second output pipe and a second input pipe; the second output pipe is connected to the first input pipe, and the first output pipe is connected to the second input pipe; The compressor is provided with an air supply inlet; the air supply outlet pipe is connected to the air supply inlet; A first heat exchanger, the two ends of which are connected to the compressor and the flow path switching device respectively; The second heat exchanger has two ends of the refrigerant inlet and outlet connected to the compressor and the flow path switching device respectively.

2. The heat pump system according to claim 1, characterized in that: The flow path switching device is provided with a first three-way reversing valve and a second three-way reversing valve; The first three-way reversing valve is provided with a heating flow path inlet, a cooling flow path inlet and a refrigerant outlet, and the refrigerant outlet is connected to the first input pipe through the second output pipe; The second three-way reversing valve is provided with a heating flow path outlet, a cooling flow path outlet and a refrigerant inlet, and the refrigerant inlet is connected to the first output pipe through the second input pipe; In the heating mode, the refrigerant flows from the first heat exchanger through the heating flow path inlet and the refrigerant inlet in sequence into the flash tank, and then flows through the refrigerant inlet and the heating flow path outlet in sequence into the second heat exchanger; In the cooling mode, the refrigerant flows from the second heat exchanger through the refrigeration flow path inlet and the refrigerant inlet in sequence into the flash tank, and then flows through the refrigerant inlet and the refrigeration flow path outlet in sequence into the first heat exchanger.

3. The heat pump system according to claim 1, characterized in that: The flow path switching device is provided with a first heating flow path conduction valve, a second heating flow path conduction valve, a first cooling flow path conduction valve and a second cooling flow path conduction valve; In the heating mode, the refrigerant flows from the first heat exchanger through the first heating flow path conduction valve into the flash tank, and flows through the second heating flow path conduction valve into the second heat exchanger; In the cooling mode, the refrigerant flows from the second heat exchanger through the first refrigeration flow path conducting valve into the flash tank, and flows through the second refrigeration flow path conducting valve into the first heat exchanger.

4. The heat pump system according to claim 2 or 3, characterized in that: The end of the first input pipe located at the flash tank is higher than the refrigerant liquid level in the flash tank; The first output pipe is located at the end of the flash tank and extends to the bottom area of ​​the flash tank, and is set at a distance from the bottom surface of the flash tank.

5. The heat pump system according to claim 4, characterized in that: The first input pipe includes a first through pipe and a plurality of second through pipes that can move up and down; The first through pipe passes through and is fixedly connected to the tank top of the flash tank, and a plurality of second through pipes are sleeved with each other. One end of the sleeved second through pipe is sleeved on one end of the first through pipe located at the flash tank.

6. The heat pump system according to claim 5, characterized in that: A liquid level detector is fixedly provided at the end of the first input pipe located at the flash tank, so that the first input pipe moves up and down according to the refrigerant liquid level detected by the liquid level detector.

7. The heat pump system according to claim 6, characterized in that: A first throttle valve is provided on the pipeline connecting the flow path switching device and the first heat exchanger; A second throttle valve is provided on the pipeline connecting the flow path switching device and the second heat exchanger.

8. The heat pump system according to claim 7, characterized in that: A first gas-liquid separation component is provided on the pipeline connecting the first heat exchanger and the compressor; A second gas-liquid separation component is arranged on the pipeline connecting the second heat exchanger and the compressor.

9. The heat pump system according to claim 8, characterized in that: The flow path switching device is provided with a heating refrigerant outlet pipe, a cooling refrigerant outlet pipe and a plurality of microbubble exhaust valves; The microbubble exhaust valve is arranged on the pipelines of the heating refrigerant outlet pipe and the cooling refrigerant outlet pipe.

10. The heat pump system according to claim 9, characterized in that: A one-way solenoid valve is arranged on the pipeline between the air supply outlet pipe and the air supply inlet, and the conducting direction of the one-way solenoid valve is the flow direction from the air supply outlet pipe to the air supply inlet.

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