Evaporator and heat pump system

Abstract

The invention discloses an evaporator and a heat pump system.The evaporator comprises a first liquid pipe assembly, a second liquid pipe assembly, a plurality of heat exchange pipe sets distributed at intervals, a plurality of vapor chambers and a plurality of fin sets, the first liquid pipe assembly comprises a first liquid distribution pipe and a first liquid collection pipe, and the second liquid pipe assembly comprises a second liquid distribution pipe and a second liquid collection pipe; each heat exchange tube group comprises a first heat exchange tube and a second heat exchange tube, the inlet end and the outlet end of the first heat exchange tube are respectively communicated with the first liquid distribution tube and the first liquid collection tube, and the inlet end and the outlet end of the second heat exchange tube are respectively communicated with the second liquid distribution tube and the second liquid collection tube; one vapor chamber corresponds to one heat exchange tube group, and the cold end and the hot end of the vapor chamber are connected with the first heat exchange tube and the second heat exchange tube in the corresponding heat exchange tube group respectively; and one fin group is connected between the adjacent heat exchange tube group and vapor chamber. The heat exchange performance between the evaporator and the external environment is good.

Description

Technical Field

[0001] The present application relates to the technical field of heat pump systems, and in particular to an evaporator and a heat pump system using the evaporator. Background Art

[0002] During the use of heat pump air conditioners, for example, in winter in cold areas, when the air conditioner is in heating mode, the outdoor temperature is low and the outdoor unit still needs to absorb heat, the evaporator temperature of the outdoor unit will drop to a lower temperature, such as below 0 degrees. In this way, the moisture on the surface of the evaporator will quickly condense into frost. Therefore, the air conditioner can generally be defrosted.

[0003] At present, heat pump air conditioners generally include a compressor, a regenerator, a throttle valve, an evaporator and a gas-liquid separator. When the air conditioner is in defrosting mode, the compressor, the regenerator, the throttle valve, the evaporator and the gas-liquid separator are connected in sequence to form a defrosting circuit. Among them, the evaporator includes a liquid distributor, a liquid collector, a heat exchange tube and a fin. The liquid distributor and the liquid collector are respectively arranged on the inlet side and the outlet side. The heat exchange tube and the fin are arranged between the liquid distributor and the liquid collector. In the defrosting mode, the transmission medium flows through the liquid distributor, the heat exchange tube and the liquid collector in sequence and then flows to the regenerator.

[0004] However, the defrosting efficiency of the above heat pump air conditioner when in the defrosting mode is low. Summary of the invention

[0005] The main purpose of the present application is to provide an evaporator and a heat pump system, aiming to improve the defrosting efficiency of the heat pump system in a defrosting mode.

[0006] In the first aspect, the present application provides an evaporator, comprising a first liquid pipe assembly, a second liquid pipe assembly, a plurality of heat exchange tube groups distributed at intervals, a plurality of heat spreaders and a plurality of fin groups, the first liquid pipe assembly comprising a first liquid distributor and a first liquid collector, the second liquid pipe assembly comprising a second liquid distributor and a second liquid collector; each heat exchange tube group comprises a first heat exchange tube and a second heat exchange tube, the inlet end and the outlet end of the first heat exchange tube are respectively connected to the first liquid distributor and the first liquid collector, the inlet end and the outlet end of the second heat exchange tube are respectively connected to the second liquid distributor and the second liquid collector; a heat spreader is arranged corresponding to a heat exchange tube group, and the cold end and the hot end of the heat spreader are respectively connected to the first heat exchange tube and the second heat exchange tube in the corresponding heat exchange tube group; a fin group is connected between adjacent heat exchange tube groups and the heat spreader.

[0007] In a possible implementation, the first liquid distributing tube and the second liquid collecting tube are located on the same side, and the first liquid collecting tube and the second liquid distributing tube are located on the same side.

[0008] In a possible implementation, the first liquid distributing tube and the second liquid distributing tube are located on the same side, and the first liquid collecting tube and the second liquid collecting tube are located on the same side.

[0009] In a possible implementation, the first heat exchange tube and the second heat exchange tube in each heat exchange tube group are arranged side by side.

[0010] In a possible implementation, a plurality of flow channels disposed side by side and arranged at intervals are formed in both the first heat exchange tube and the second heat exchange tube.

[0011] In the second aspect, the present application provides a heat pump system, including a compressor, a gas cooler, a regenerator and the above-mentioned evaporator; the regenerator includes a cooling module and a return air main pipe, and the heat pump system has a first working mode and a second working mode; when the heat pump system is in the first working mode, the compressor, the gas cooler, the cooling module, the evaporator, and the return air main pipe are connected in sequence to form a first circulation loop for the transmission working medium to flow, and the transmission working medium flows through the first liquid pipe assembly when flowing in the first circulation loop; when the heat pump system is in the second working mode, the compressor, the evaporator and the return air main pipe are connected in sequence to form a second circulation loop for the transmission working medium to flow, and the transmission working medium passes through the evaporator twice when flowing in the second circulation loop, and flows through the second liquid pipe assembly and the first liquid pipe assembly in sequence.

[0012] In a possible implementation, the heat pump system provided in the present application also includes a regulating valve; the regulating valve is arranged on the second circulation loop, and when the heat pump system is in the second operating mode, the regulating valve connects the compressor and the liquid distribution pipe of the second liquid pipe assembly.

[0013] In one possible implementation, the heat pump system provided in the present application also includes a gas-liquid separator; when the heat pump system is in a first operating mode, the compressor, the gas cooler, the cooling module, the evaporator, the return air main pipe and the gas-liquid separator are connected in sequence to form a first circulation loop; when the heat pump system is in a second operating mode, the compressor, the evaporator, the return air main pipe and the gas-liquid separator are connected in sequence to form a second circulation loop.

[0014] In one possible implementation, the heat pump system provided in the present application also includes a throttle valve; when the heat pump system is in a first operating mode, the throttle valve is connected between the cooling module and the evaporator; when the heat pump system is in a second operating mode, the throttle valve is connected between the second liquid pipe assembly and the first liquid pipe assembly.

[0015] In one possible implementation, the heat pump system provided in the present application also includes a first stop valve, which is arranged on the first circulation loop; when the heat pump system is in a first operating mode, the first stop valve is closed to connect the compressor and the gas cooler; when the heat pump system is in a second operating mode, the first stop valve is disconnected.

[0016] In one possible implementation, the heat pump system provided in the present application also includes a second stop valve, which is arranged on the second circulation loop; when the heat pump system is in the first operating mode, the second stop valve is disconnected; when the heat pump system is in the second operating mode, the second stop valve is closed, connecting the compressor and the liquid distribution pipe of the second liquid pipe assembly.

[0017] In one possible implementation, the heat pump system provided in the present application also includes a one-way valve, which is arranged on the second circulation loop; when the heat pump system is in the second operating mode, the one-way valve connects the collecting pipe of the second liquid pipe assembly and the liquid distribution pipe of the first liquid pipe assembly.

[0018] In the evaporator and heat pump system in the embodiment of the present application, a heat spreader is provided in the evaporator, and the cold end and the hot end of the heat spreader are respectively connected to the first heat exchange tube and the second heat exchange tube in the corresponding heat exchange tube group. Therefore, during the defrosting process of the outdoor unit, when a transmission medium with a higher temperature flows into the evaporator, it will promote the phase change medium at the hot end of the heat spreader to evaporate into a gaseous state, and the vapor will then flow to the cold end of the heat spreader through the flow path in the heat spreader, and release the latent heat at the cold end to transfer to the wall surface of the heat spreader, condense into a liquid state, and the liquid phase change medium accumulated at the cold end flows back to the hot end of the heat spreader under the action of gravity, and then absorbs heat and evaporates. Through the continuous evaporation and condensation of the phase change medium, heat is continuously transferred to the entire heat spreader to achieve defrosting. In this way, the fast heat transfer characteristic of the heat spreader can be utilized to improve the heat exchange efficiency between the evaporator and the outside world, so as to improve the defrosting efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0020] Figure 1 A schematic diagram of the structure of the evaporator provided in the embodiment of the present application;

[0021] Figure 2 for Figure 1 Cross-sectional view along AA direction;

[0022] Figure 3 A schematic diagram of the local structure of a heat pump system provided in an embodiment of the present application;

[0023] Figure 4 A schematic diagram of the flow direction of the working fluid transmitted by the heat pump system in the heating mode provided in the embodiment of the present application;

[0024] Figure 5A schematic diagram of the flow direction of the working fluid transmitted by the heat pump system in the defrost mode provided in an embodiment of the present application.

[0025] Description of Figure Numbers:

[0026] 2. Heat exchange tube group; 3. Fin group; 4. Heat sink;

[0027] 10. Evaporator; 1A. First liquid pipe assembly; 1B. Second liquid pipe assembly; 11. Liquid distributor; 12. Liquid collector; 20. Compressor; 30. Gas cooler; 40. Regenerator; 41. Cooling module; 42. Return gas main; 50. First circulation loop; 60. Second circulation loop; 80. Regulating valve; 90. Gas-liquid separator;

[0028] 11A, first liquid distribution pipe; 11B, second liquid distribution pipe; 12A, first liquid collection pipe; 12B, second liquid collection pipe; 21A, first heat exchange pipe; 21B, second heat exchange pipe; 211, flow channel; 110, throttle valve; 120, second stop valve; 130, one-way valve; 140, first stop valve.

[0029] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0030] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0031] It should be noted that all directional indications in the embodiments of the present application (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0032] In addition, the descriptions of "first", "second", etc. in this application are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0033] In this application, unless otherwise clearly specified and limited, the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0034] In addition, the technical solutions between the various embodiments of the present application can be combined with each other, but it must be based on the fact that ordinary technicians in the field can implement it. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0035] In electrical equipment that uses a heat pump system, such as a water heater or a heat pump air conditioner, take a heat pump air conditioner as an example. In winter in cold areas, when the air conditioner is in heating mode, the outdoor temperature is low, and the outdoor unit still needs to absorb heat, the evaporator temperature of the outdoor unit will drop to a lower temperature, such as below 0 degrees. In this way, the moisture on the surface of the evaporator will quickly condense into frost. If the frost on the surface of the evaporator cannot be effectively removed, it will affect the heat exchange capacity of the evaporator itself, etc. Therefore, in order to maintain the stability of the air conditioner during operation, the air conditioner is generally able to defrost.

[0036] At present, heat pump air conditioners generally include a compressor, a regenerator, a throttle valve, an evaporator and a gas-liquid separator. When the air conditioner is in defrosting mode, the compressor, the regenerator, the throttle valve, the evaporator and the gas-liquid separator are connected in sequence to form a defrosting circuit. Among them, the evaporator includes a liquid distributor, a liquid collector, a heat exchange tube and a fin. The liquid distributor and the liquid collector are respectively arranged on the inlet side and the outlet side. The heat exchange tube and the fin are arranged between the liquid distributor and the liquid collector. Generally, frost will condense on the heat exchange tube and the fin. In the defrosting mode, the transmission medium flows through the liquid distributor, the heat exchange tube and the liquid collector in sequence and then flows to the regenerator.

[0037] It should be noted that, since most traditional transmission fluids use hydrochlorofluorocarbons (HCFCs), these transmission fluids are not only harmful to the atmospheric ozone layer, but also aggravate the greenhouse effect, posing a serious threat to the environment. Therefore, the transmission fluid currently used in heat pump systems is mostly carbon dioxide (CO2), which is environmentally friendly and has excellent heating performance, especially at low temperatures. CO2 has good thermal performance. Of course, in the embodiments of the present application, the choice of transmission fluid is not limited to CO2, but can also be other types, and no specific limitation is made here.

[0038] However, in the defrost mode of the above-mentioned heat pump air conditioner, the temperature of the transmission medium flowing into the evaporator is relatively low, so that the temperature transmitted to the surface of the heat exchange tube and the surface of the fin is also relatively low, which will make the defrosting efficiency slower. Moreover, due to the structural limitations of the evaporator itself, the heat exchange capacity of the evaporator is relatively poor, which makes the heat transfer slower, which will also affect the defrosting efficiency.

[0039] Based on this, the embodiments of the present application provide an evaporator and a heat pump system, which can improve the defrosting efficiency.

[0040] The embodiments of the present application will be described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0041] See also Figure 1 and Figure 2 As shown, Figure 1 This is a schematic diagram of the structure of the evaporator provided in the embodiment of the present application. Figure 2 for Figure 1 Cross-sectional view along the AA direction. As shown in the figure, the present embodiment provides an evaporator 10, including a first liquid pipe assembly 1A and a second liquid pipe assembly 1B, wherein the first liquid pipe assembly 1A includes a first liquid distributor 11A and a first liquid collector 12A, and the second liquid pipe assembly 1B includes a second liquid distributor 11B and a second liquid collector 12B, wherein the first liquid distributor 11A and the second liquid distributor 11B form the inlet side of the evaporator 10, and the first liquid collector 12A and the second liquid collector 12B form the outlet side of the evaporator 10.

[0042] That is to say, during the operation of the evaporator 10, the transmission medium can flow in from the first liquid distribution pipe 11A and flow out from the first liquid collection pipe 12A, or flow in from the second liquid distribution pipe 11B and flow out from the second liquid collection pipe 12B. In the following introduction, the flow direction of the transmission medium in the first liquid pipe assembly 1A and the second liquid pipe assembly 1B will be described in detail in conjunction with the operation process of the heat pump system.

[0043] Of course, the function of the evaporator 10 is to achieve heat exchange with the outside world. Therefore, in this embodiment, the evaporator 10 should also include a plurality of heat exchange tube groups 2 distributed at intervals, each heat exchange tube group 2 includes a first heat exchange tube 21A and a second heat exchange tube 21B, wherein the inlet end of the first heat exchange tube 21A is connected to the first liquid distributor 11A, the outlet end of the first heat exchange tube 21B is connected to the first liquid collector 12A, the inlet end of the second heat exchange tube 21B is connected to the second liquid distributor 11B, and the outlet end of the second heat exchange tube 21B is connected to the second liquid collector 12B.

[0044] That is to say, during the operation of the evaporator 10, the transmission medium can flow in from the first liquid distributor 11A, flow through the first heat exchange tube 21A, flow to the first collecting tube 12A, and flow out of the evaporator 10 from the first collecting tube 12A; or, the transmission medium can flow in from the second liquid distributor 11B, flow through the second heat exchange tube 21B, flow to the second collecting tube 12B, and flow out from the second collecting tube 12B.

[0045] Generally, in order to improve the thermal conductivity of the heat exchange tube group 2, the above-mentioned heat exchange tube 21 will adopt a flat tube, and each heat exchange tube 21 will be formed with a plurality of flow channels 211 arranged side by side and spaced apart. That is to say, in this embodiment, the heat exchange tube 21 adopts a microchannel flat tube and is made of aluminum, which has the advantages of good thermal conductivity, strong corrosion resistance, strong plasticity, light weight and low cost.

[0046] Furthermore, in order to increase the heat exchange area between the evaporator 10 and the external environment, the evaporator 10 provided in this embodiment should also include a plurality of fin groups 3, and each fin group 3 is supported between two adjacent heat exchange tube groups 2 to increase the heat exchange area between the evaporator 10 and the external environment, thereby improving the heat exchange efficiency of the evaporator 10.

[0047] It is understandable that in order to further increase the heat exchange area between the fin group 3 and the external environment, the fin group 3 can be set as a spiral or wavy shape, that is, multiple fins can be connected together in a spiral or wavy shape, so that the heat exchange area between the fin group 3 and the external environment can be further increased. Multiple fins can be connected together by welding. Here, the specific shape of the fin group 3 and the specific connection method between the fins are not limited.

[0048] From the above, it can be seen that in the relevant technology, the evaporator is formed by integrating a liquid distribution tube, a flat tube, a liquid collecting tube and a fin. It is not difficult to understand that under this structure, the heat exchange efficiency between the evaporator and the outside world is low. Therefore, in this embodiment, in order to improve the heat exchange efficiency between the evaporator 10 and the external environment and improve the defrosting efficiency, the structure of the evaporator 10 can be improved to improve the defrosting efficiency.

[0049] Based on this, the evaporator 10 provided in this embodiment also includes a plurality of heat spreaders 4, one heat spreader 4 is correspondingly arranged with one heat exchange tube group 2, and the cold end and the hot end of the heat spreader 4 are respectively connected with the first heat exchange tube 21A and the second heat exchange tube 21B in the corresponding heat exchange tube group 2, that is, when the cold end of the heat spreader 4 is connected with the first heat exchange tube 21A, the hot end of the heat spreader 4 is connected with the second heat exchange tube 21B; when the cold end of the heat spreader 4 is connected with the second heat exchange tube 21B, the hot end of the heat spreader 4 is connected with the first heat exchange tube 21A. Among them, the cold end of the heat spreader 4 can be understood as the heat absorbing end of the heat spreader 4, and the hot end of the heat spreader 4 can be understood as the heat releasing end of the heat spreader 4.

[0050] Specifically, the inner wall of the heat spreader 4 has a vacuum cavity with a microstructure, and the heat spreader 4 is usually made of copper. When heat is conducted from the heat source to the hot end, the coolant in the cavity begins to vaporize after being heated in a low vacuum environment, absorbing heat energy and expanding rapidly in volume. The gas phase cooling medium quickly fills the entire cavity. When the gas phase working medium contacts the cold end, condensation occurs, and the heat accumulated during evaporation is released through the condensation phenomenon. The condensed coolant returns to the evaporation heat source through the microstructured capillary channel, and this operation will be repeated in the cavity.

[0051] During the defrosting process, when a relatively high temperature transmission medium flows into the evaporator 10, the phase change medium at the hot end of the heat spreader 4 is promoted to evaporate into a gaseous state. The vapor then flows to the cold end of the heat spreader 4 through the flow path in the heat spreader 4, and releases latent heat at the cold end and transfers it to the wall of the heat spreader 4, condensing into a liquid state. The liquid phase change medium accumulated at the cold end flows back to the hot end of the heat spreader 4 under the action of gravity, and then absorbs heat and evaporates. Through the continuous evaporation and condensation of the phase change medium, heat is continuously transferred to the entire heat spreader 4 to achieve defrosting. In this way, the heat exchange efficiency between the evaporator 10 and the outside world can be improved during the defrosting process to improve the defrosting efficiency.

[0052] The fin group 3 is connected between the adjacent heat exchange tube group 2 and the soaking plate 4. In the specific implementation of this embodiment, the soaking plate 4 is connected below the heat exchange tube group 2, the fin group 3 is connected below the soaking plate 4, and the soaking plate 4 and the heat exchange tube group 2 and the fin group 3 can be connected by welding. Here, there is no specific restriction on the connection method between the soaking plate 4 and the heat exchange tube group 2 and the fin group 3.

[0053] The number of heat exchange tube groups 2, the number of heat spreaders 4 and the number of fin groups 3 are determined according to the size of the outdoor unit. Here, no specific restrictions are imposed on the number of heat exchange tube groups 2, the number of heat spreaders 4 and the number of fin groups 3.

[0054] In the following description, the example in which the cold end of the vapor chamber 4 is connected to the first heat exchange tube 21A and the hot end of the vapor chamber 4 is connected to the second heat exchange tube 21B is taken as an example for further description.

[0055] It can be understood that the inlet and outlet ends of the first heat exchange tube 21A are respectively connected to the first liquid distributor 11A and the first liquid collector 12A, the inlet and outlet ends of the second heat exchange tube 21B are respectively connected to the second liquid distributor 11B and the second liquid collector 12B, and the cold end of the heat spreader 4 is connected to the first heat exchange tube 21A, and the hot end of the heat spreader 4 is connected to the second heat exchange tube 21B. Therefore, the flow direction of the transmission medium in the first heat exchange tube 21A should be opposite to the flow direction of the transmission medium in the second heat exchange tube 21B. That is to say, the first liquid distributor 11A and the second liquid collector 12B are located on the same side, and the first liquid collector 12A and the second liquid distributor 11B are located on the same side; of course, in some other embodiments, through the setting of the pipeline, it can also be that the first liquid distributor 11A and the second liquid distributor 11B are located on the same side, and the first liquid collector 12A and the second liquid collector 12B are located on the same side. Here, the positional relationship between the first liquid distributing pipe 11A and the second liquid distributing pipe 11B and the positional relationship between the first liquid collecting pipe 12A and the second liquid collecting pipe 12B are not limited.

[0056] In order to improve the compactness of the structure of the evaporator 10 and to enable the vapor chamber 4 to be connected to the two heat exchange tubes 21 at the same time, in some optional embodiments, the first heat exchange tube 21A and the second heat exchange tube 21B in each heat exchange tube group 2 are arranged side by side. In this way, the vapor chamber 4 can be connected to the first heat exchange tube 21A and the second heat exchange tube 21B, so that the evaporator 10 provided in this embodiment has better heat exchange performance.

[0057] See also Figures 3 to 5 , Figure 3 A schematic diagram of a partial structure of a heat pump system provided in an embodiment of the present application, Figure 4 A schematic diagram of the flow direction of the working fluid transmitted by the heat pump system in the heating mode provided in the embodiment of the present application, Figure 5 A schematic diagram of the flow direction of the transmission medium of the heat pump system in the defrost mode provided in the embodiment of the present application. As shown in the figure, the present embodiment also provides a heat pump system, including a compressor 20, a gas cooler 30, a regenerator 40 and the evaporator 10 in the above embodiment; the regenerator 40 includes a cooling module 41 and a return air main 42, and the heat pump system has a first working mode and a second working mode, the first working mode here can be understood as a heating mode, and the second working mode here can be understood as a defrost mode.

[0058] Specifically, Figure 4As shown, when the heat pump system is in the first working mode, i.e., the heating mode, the compressor 20, the gas cooler 30, the cooling module 41, the evaporator 10, and the return air main pipe 42 are connected in sequence to form a first circulation loop 50 for the transmission medium to flow, and the transmission medium flows through the first liquid pipe assembly 1A when flowing in the first circulation loop 50, that is, the transmission medium flows into the first heat exchange pipe 21A through the first liquid distribution pipe 11A, and then flows into the return air main pipe through the first liquid collecting pipe 12A; when the heat pump system is in the second working mode, i.e., the defrosting ... The machine 20, the evaporator 10 and the return gas main pipe 42 are connected in sequence to form a second circulation loop 60 for the transmission working medium to flow, and the transmission working medium passes through the evaporator 10 twice when flowing in the second circulation loop 60, and flows through the second liquid pipe assembly 1B and the first liquid pipe assembly 1A in sequence, that is, the transmission working medium flows into the second heat exchange tube 21B from the second liquid distribution pipe 11B, and then flows out through the second liquid collection pipe 12B, and then flows into the first heat exchange tube 21A through the first liquid distribution pipe 11A, and then flows to the return gas main pipe through the first liquid collection pipe 12A.

[0059] It should be noted that, in the present embodiment, the high-temperature and high-pressure gas compressed by the compressor 20 can flow directly into the evaporator 10 for defrosting. On the one hand, the flow path of the compressed gas is smaller, so that it can flow to the evaporator 10 for defrosting in a shorter time; on the other hand, the temperature of the gas flowing into the compressor 20 is higher, and combined with the fast heat transfer performance of the heat spreader 4, the defrosting efficiency can be further improved.

[0060] It should be noted that no matter whether the heat pump system is in heating mode or defrost mode, there is only one flow path for the high-temperature and high-pressure gas flowing out of the compressor 20. In the heating mode, this is to prevent part of the working fluid from flowing directly into the evaporator 10; in the defrost mode, this is to prevent part of the working fluid from flowing directly into the gas cooler 30.

[0061] In some specific implementations, the heat pump system provided in this embodiment further includes a first stop valve 140 and a second stop valve 120;

[0062] The first stop valve 140 is disposed on the first circulation loop 50; when the heat pump system is in a heating mode, the first stop valve 140 is closed to connect the compressor 20 and the gas cooler 30; when the heat pump system is in a defrosting mode, the first stop valve 140 is disconnected;

[0063] The second stop valve 120 is arranged on the second circulation loop 60; when the heat pump system is in the first working mode, the second stop valve 120 is disconnected; when the heat pump system is in the second working mode, the second stop valve 120 is closed, connecting the compressor 20 and the second liquid distribution pipe 11B. In this way, through the arrangement of the first stop valve 140 and the second stop valve 120, in the heating mode, the high-temperature and high-pressure gas flowing out of the compressor 20 can all flow into the gas cooler 30; in the defrosting mode, the high-temperature and high-pressure gas flowing out of the compressor 20 can all flow into the evaporator 10.

[0064] In order to make the compressor 20 have a relatively stable return air superheat and to regulate the flow rate of the transmission medium in the heating mode, the heat pump system provided in this embodiment may further include a throttle valve 110; when the heat pump system is in the heating mode, the throttle valve 110 is connected between the cooling module 41 and the evaporator 10; when the heat pump system is in the defrosting mode, the throttle valve 110 is connected between the second liquid pipe assembly 1B and the first liquid pipe assembly 1A. In other words, the throttle valve 110 is both in the first circulation loop 50 and in the second circulation loop 60, and in the defrosting mode, by regulating the flow rate of the transmission medium, the compressor 20 can have a relatively stable return air superheat.

[0065] Furthermore, the heat pump system provided in this embodiment further includes a regulating valve 80; the regulating valve 80 is arranged on the second circulation loop 60, and when the heat pump system is in the second working mode, the regulating valve 80 connects the compressor 20 and the liquid distribution pipe 11B. In this way, by setting the regulating valve 80, the amount of high-temperature and high-pressure gas flowing through the second circulation loop 60 can be properly adjusted, while maintaining the exhaust superheat of the compressor 20 stable, and the defrosting efficiency can be improved.

[0066] The greater the amount of high-temperature and high-pressure gas flowing through the second circulation loop 60 , the higher the defrosting efficiency.

[0067] Of course, in order to prevent the liquid working medium from flowing into the compressor 20, the heat pump system provided in this embodiment may further include a gas-liquid separator 90; when the heat pump system is in the first working mode, the compressor 20, the gas cooler 30, the cooling module 41, the evaporator 10, the return gas main pipe 42 and the gas-liquid separator 90 are sequentially connected to form a first circulation loop 50; when the heat pump system is in the second working mode, the compressor 20, the evaporator 10, the return gas main pipe 42 and the gas-liquid separator 90 are sequentially connected to form a second circulation loop 60. In this way, by setting the gas-liquid separator 90, it is possible to prevent the liquid transmission working medium from flowing into the compressor 20 to a certain extent, and by setting the gas-liquid separator 90, the compressor 20 can maintain a relatively stable return gas superheat, so that the compressor 20 maintains a good performance.

[0068] Furthermore, in order to prevent the transmission medium from flowing back on the second circulation loop 60, the heat pump system provided in this embodiment further includes a one-way valve 130, which is arranged on the second circulation loop 60; when the heat pump system is in the second working mode, the one-way valve 130 connects the second liquid collecting pipe 12B with the throttle valve 110, that is, the one-way valve 130 is located upstream of the throttle valve 110. In this way, the one-way valve 130 can prevent the transmission medium from flowing back to a certain extent, so that the heat pump system provided in this embodiment can perform normal defrosting work.

[0069] The following is a detailed introduction to the working medium flow direction of the heat pump system provided in this embodiment in two modes.

[0070] When the heat pump system provided in this embodiment is in heating mode, the first stop valve 140 is closed, the second stop valve 120 is disconnected, and the regulating valve 80 is closed. After CO2 flows through the compressor 20 and is compressed into high-temperature and high-pressure gas, it flows into the gas cooler 30; in the gas cooler 30, CO2 is isobarically cooled to a low-temperature state; then CO2 is further cooled in the cooling module 41 of the regenerator 40 to reach a lower temperature, and the high-pressure CO2 flows through the throttle valve 110, and the pressure and temperature are reduced at the same time. It vaporizes and absorbs heat to the saturated gas point in the first heat exchange tube 21A of the evaporator 10, and the heat spreader 4 also absorbs heat in the air and transfers it to the first heat exchange tube 21A to help heat exchange. The heated working fluid in the first heat exchange tube 21A enters the return gas main pipe 42 of the regenerator 40 again to be heated, and enters the gas-liquid separator 90 for separation, and the separated gas enters the inlet of the compressor 20, thereby completing the cycle.

[0071] When the heat pump system provided in this embodiment is in defrost mode, the first stop valve 140 is disconnected, the second stop valve 120 is closed, and the opening of the regulating valve 80 is adjusted. CO2 flows through the compressor 20 and is compressed into high-temperature and high-pressure gas. It passes through the second stop valve 120 and the regulating valve 80 and enters the second heat exchange tube 21B of the evaporator 10 to release heat. The heat is transferred to the first heat exchange tube 21A through the heat spreader 4 for defrosting. The cooled fluid passes through the one-way valve 130 and the throttle valve 110, and the fluid pressure and temperature are reduced at the same time. Then, the fluid enters the first heat exchange tube 21A of the evaporator 10 for evaporation. The evaporated fluid enters the regenerator 40 for heat exchange with the high-pressure side fluid, and then enters the gas-liquid separator 90. The separated gas enters the inlet of the compressor 20, thereby completing the cycle.

[0072] It should be noted that the heat pump system provided in this embodiment can be a heat pump air conditioner or a heat pump water heater. When the heat pump system provided in this embodiment is a heat pump air conditioner, the heat pump system should also include an indoor unit connected to the gas cooler 30; when the heat pump system provided in this embodiment is a heat pump water heater, the heat pump system should also include a water tank connected to the gas cooler 30. Other modules or structures included in the heat pump system are not introduced here.

[0073] Taking a heat pump water heater as an example, when the heat pump system is in heating mode, in the gas cooler 30, the high-temperature CO2 will heat the cooling water to the target temperature; when the heat pump system is in defrost mode, the cooling water on the return water inlet side does not enter or partially enters the gas cooler 30.

[0074] The above description is only a preferred embodiment of the present application, and does not limit the patent scope of the present application. All equivalent structural changes made based on the concept of the present application and the contents of the present application description and drawings, or direct / indirect application in other related technical fields are included in the patent protection scope of the present application.

Claims

1. An evaporator, characterized in that: include: a first liquid pipe assembly and a second liquid pipe assembly, wherein the first liquid pipe assembly includes a first liquid distributing pipe and a first liquid collecting pipe, and the second liquid pipe assembly includes a second liquid distributing pipe and a second liquid collecting pipe; A plurality of heat exchange tube groups distributed at intervals, each of the heat exchange tube groups comprising a first heat exchange tube and a second heat exchange tube, the inlet end and the outlet end of the first heat exchange tube are respectively connected to the first liquid distributor and the first liquid collector, and the inlet end and the outlet end of the second heat exchange tube are respectively connected to the second liquid distributor and the second liquid collector; A plurality of vapor chambers, wherein one vapor chamber is disposed correspondingly to one heat exchange tube group, and a cold end and a hot end of the vapor chamber are respectively connected to a first heat exchange tube and a second heat exchange tube in the corresponding heat exchange tube group; and; A plurality of fin groups, one of the fin groups is connected between the adjacent heat exchange tube groups and the heat spreader.

2. The evaporator according to claim 1, characterized in that The first liquid distributing pipe and the second liquid collecting pipe are located on the same side, and the first liquid collecting pipe and the second liquid distributing pipe are located on the same side; or, The first liquid distributing tube and the second liquid distributing tube are located on the same side, and the first liquid collecting tube and the second liquid collecting tube are located on the same side.

3. The evaporator according to claim 1 or 2, characterized in that: The first heat exchange tube and the second heat exchange tube in each heat exchange tube group are arranged side by side.

4. The evaporator according to claim 1 or 2, characterized in that: A plurality of flow channels arranged side by side and at intervals are formed in the first heat exchange tube and the second heat exchange tube.

5. A heat pump system, characterized in that: It comprises a compressor, a gas cooler, a regenerator and an evaporator as claimed in any one of claims 1 to 4; The regenerator includes a cooling module and a return air main pipe, and the heat pump system has a first working mode and a second working mode; When the heat pump system is in a first working mode, the compressor, the gas cooler, the cooling module, the evaporator, and the return gas main pipe are sequentially connected to form a first circulation loop for the transmission medium to flow, and the transmission medium flows through the first liquid pipe assembly when flowing in the first circulation loop; When the heat pump system is in the second working mode, the compressor, the evaporator and the return air main are connected in sequence to form a second circulation loop for the transmission working medium to flow, and the transmission working medium passes through the evaporator twice when flowing in the second circulation loop, and flows through the second liquid pipe assembly and the first liquid pipe assembly in sequence.

6. The heat pump system according to claim 5, characterized in that: Also includes a regulating valve; The regulating valve is arranged on the second circulation loop. When the heat pump system is in the second working mode, the regulating valve is connected to the compressor and the liquid distribution pipe of the second liquid pipe assembly.

7. The heat pump system according to claim 5 or 6, characterized in that: Also included is a gas-liquid separator; When the heat pump system is in the first working mode, the compressor, the gas cooler, the cooling module, the evaporator, the return gas main pipe and the gas-liquid separator are connected in sequence to form the first circulation loop; When the heat pump system is in the second working mode, the compressor, the evaporator, the return air main pipe and the gas-liquid separator are connected in sequence to form the second circulation loop.

8. The heat pump system according to claim 5 or 6, characterized in that: Also includes throttle valve; When the heat pump system is in the first working mode, the throttle valve is connected between the cooling module and the evaporator; When the heat pump system is in the second operating mode, the throttle valve is connected between the second liquid pipe assembly and the first liquid pipe assembly.

9. The heat pump system according to claim 5 or 6, characterized in that: It also includes a first stop valve, which is arranged on the first circulation loop; When the heat pump system is in the first working mode, the first stop valve is closed to connect the compressor and the gas cooler; When the heat pump system is in the second operating mode, the first stop valve is disconnected.

10. The heat pump system according to claim 5 or 6, characterized in that: Also includes a second stop valve, wherein the second stop valve is arranged on the second circulation loop; When the heat pump system is in the first working mode, the second stop valve is disconnected; When the heat pump system is in the second working mode, the second stop valve is closed to connect the compressor with the liquid distribution pipe of the second liquid pipe assembly.

11. The heat pump system according to claim 5 or 6, characterized in that: Also includes a one-way valve, wherein the one-way valve is arranged on the second circulation loop; When the heat pump system is in the second working mode, the one-way valve connects the liquid collecting pipe of the second liquid pipe assembly with the liquid distributing pipe of the first liquid pipe assembly.

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