Evaporator and heat pump system

Abstract

The present application discloses an evaporator and heat pump system. The evaporator disclosed in the present application includes a first liquid pipe assembly, a second liquid pipe assembly, a plurality of spaced-apart heat exchange tube groups, a plurality of vapor chambers, and a plurality of fin groups. The first liquid pipe assembly includes a first liquid distributor and a first liquid header, and the second liquid pipe assembly includes a second liquid distributor and a second liquid header. Each heat exchange tube group includes a first heat exchange tube and a second heat exchange tube, the inlet and outlet ends of the first heat exchange tube being connected to the first liquid distributor and the first liquid header, respectively, and the inlet and outlet ends of the second heat exchange tube being connected to the second liquid distributor and the second liquid header, respectively. A vapor chamber is provided corresponding to each heat exchange tube group, and the cold end and hot end of the vapor chamber 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 vapor chambers. The evaporator of the present application has good heat exchange performance with the external environment.

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] Currently, heat pump air conditioners typically include a compressor, regenerator, throttle valve, evaporator, and gas-liquid separator. When the air conditioner is in defrost mode, the compressor, regenerator, throttle valve, evaporator, and gas-liquid separator are sequentially connected to form a defrost circuit. The evaporator includes a liquid distributor, a liquid collector, heat exchange tubes, and fins. The distributor and collector are located on the inlet and outlet sides, respectively, with the heat exchange tubes and fins located between them. In defrost mode, the working fluid flows through the distributor, heat exchange tubes, and collector in sequence before flowing 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 this application is to provide an evaporator and a heat pump system, aiming to improve the defrosting efficiency of the heat pump system in defrost 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 spaced-apart heat exchange tube groups, 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, 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 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 pipe and the second liquid collecting pipe are located on the same side. The first liquid collecting pipe and the second liquid distributing pipe are located on the same side.

[0008] In a possible implementation, the first liquid distributing pipe and the second liquid distributing pipe are located on the same side, and the first liquid collecting pipe and the second liquid collecting pipe 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 arranged side by side and spaced apart 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, 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 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 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 one possible implementation, the heat pump system provided in the present application further 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, gas cooler, cooling module, evaporator, return air main and 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, evaporator, return air main and 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, connecting 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. The vapor then flows to the cold end of the heat spreader through the flow path in the heat spreader, and releases latent heat at the cold end and transfers it to the wall surface of the heat spreader, 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 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, thereby improving 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 following briefly introduces the drawings required for use in the embodiments or the description of the prior art. 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 an 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 partial 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 medium of the heat pump system provided in the embodiment of the present application in the heating mode;

[0024] Figure 5A schematic diagram of the flow direction of the working medium 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 air main; 50. First circulation loop; 60. Second circulation loop; 80. Control 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 objectives, 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 this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts 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 various 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 terms "first," "second," and so on, used in this application are for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly specifying the number of the technical features indicated. Therefore, a feature specified as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0033] In this application, unless otherwise specified or limited, the terms "connection" and "fixation" should be understood in a broad sense. For example, "fixation" can mean fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; internal communication between two elements or interaction between two elements, unless otherwise specified. For those skilled in the art, 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 this field can implement it. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0035] In electrical equipment using heat pump systems, such as water heaters or heat pump air conditioners, for example, in cold winter regions, when the air conditioner is in heating mode and the outdoor temperature is low, the outdoor unit still needs to absorb heat. The outdoor unit's evaporator temperature will drop to a low temperature, such as below 0 degrees Celsius. As a result, moisture on the evaporator surface will quickly condense into frost. If the frost on the evaporator surface cannot be effectively removed, it will affect the evaporator's heat exchange capacity. Therefore, to maintain stable operation, air conditioners are generally equipped with a defrost function.

[0036] Currently, heat pump air conditioners typically include a compressor, regenerator, throttle valve, evaporator, and gas-liquid separator. When the air conditioner is in defrost mode, the compressor, regenerator, throttle valve, evaporator, and gas-liquid separator are sequentially connected to form a defrost circuit. The evaporator includes a liquid distributor, a liquid collector, heat exchange tubes, and fins. The distributor and collector are located on the inlet and outlet sides, respectively, with the heat exchange tubes and fins located between them. Frost typically condenses on the heat exchange tubes and fins. In defrost mode, the working fluid flows through the distributor, heat exchange tubes, and collector pipes before flowing to the regenerator.

[0037] It should be noted that, since traditional transmission fluids mostly use hydrochlorofluorocarbons (HCFCs), these transmission fluids are not only harmful to the atmospheric ozone layer, but also exacerbate 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 both environmentally friendly and has excellent heating performance, especially at low temperatures. CO2 has excellent thermal performance. Of course, in the embodiments of the present application, the choice of transmission fluid is not limited to CO2, and other types can also be used. No specific limitation is imposed 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 defrost 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 defrost efficiency.

[0039] Based on this, an embodiment of the present application provides an evaporator and a heat pump system that can improve defrosting efficiency.

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

[0041] See 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 direction AA. As shown in the figure, this 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 distribution pipe 11A and a first liquid collection pipe 12A, and the second liquid pipe assembly 1B includes a second liquid distribution pipe 11B and a second liquid collection pipe 12B, wherein the first liquid distribution pipe 11A and the second liquid distribution pipe 11B form the inlet side of the evaporator 10, and the first liquid collection pipe 12A and the second liquid collection pipe 12B form the outlet side of the evaporator 10.

[0042] That is, during the operation of evaporator 10, the working fluid can flow into first liquid distribution pipe 11A and out of first liquid collection pipe 12A, or it can flow into second liquid distribution pipe 11B and out of second liquid collection pipe 12B. The following description will detail the flow of the working fluid in first liquid pipe assembly 1A and second liquid pipe assembly 1B in conjunction with the operation 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 spaced-apart heat exchange tube groups 2, each heat exchange tube group 2 including 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 distribution tube 11A, the outlet end of the first heat exchange tube 21B is connected to the first liquid collection tube 12A, the inlet end of the second heat exchange tube 21B is connected to the second liquid distribution tube 11B, and the outlet end of the second heat exchange tube 21B is connected to the second liquid collection tube 12B.

[0044] That is to say, during the operation of the evaporator 10, the transmission medium can flow in from the first liquid distribution pipe 11A, flow through the first heat exchange tube 21A, flow to the first collecting pipe 12A, and flow out of the evaporator 10 from the first collecting pipe 12A; or, the transmission medium can flow in from the second liquid distribution pipe 11B, flow through the second heat exchange tube 21B, flow to the second collecting pipe 12B, and flow out from the second collecting pipe 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 is 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 multiple 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 understood that to further increase the heat exchange area between the fin assembly 3 and the external environment, the fin assembly 3 can be configured as a spiral or wavy shape. In other words, multiple fins can be connected together in a spiral or wavy shape. This can further increase the heat exchange area between the fin assembly 3 and the external environment. The multiple fins can be connected together by welding. The specific shape of the fin assembly 3 and the specific connection method between the fins are not limited here.

[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 defrost efficiency, the structure of the evaporator 10 can be improved to improve the defrost efficiency.

[0049] Based on this, the evaporator 10 provided in this embodiment also includes multiple vapor chambers 4, each vapor chamber 4 being provided corresponding to a heat exchange tube group 2, and the cold end and hot end of the vapor chamber 4 being connected to the first heat exchange tube 21A and the second heat exchange tube 21B in the corresponding heat exchange tube group 2, respectively. That is, when the cold end of the vapor chamber 4 is connected to the first heat exchange tube 21A, the hot end of the vapor chamber 4 is connected to the second heat exchange tube 21B; when the cold end of the vapor chamber 4 is connected to the second heat exchange tube 21B, the hot end of the vapor chamber 4 is connected to the first heat exchange tube 21A. The cold end of the vapor chamber 4 can be understood as the heat absorbing end of the vapor chamber 4, and the hot end of the vapor chamber 4 can be understood as the heat releasing end of the vapor chamber 4.

[0050] Specifically, the inner wall of vapor chamber 4, typically made of copper, features a microstructured vacuum cavity. When heat is transferred from the heat source to the hot end, the coolant within the cavity, heated in a low vacuum environment, begins to vaporize. This vapor absorbs heat energy and rapidly expands, rapidly filling the cavity. When the vapor contacts the cold end, it condenses, releasing the heat accumulated during evaporation. The condensed coolant then flows back to the evaporation heat source via the microstructured capillaries, a process that repeats itself repeatedly within the cavity.

[0051] During the defrosting process, when a relatively high-temperature transmission medium flows into the evaporator 10, it promotes the evaporation of the phase change medium at the hot end of the heat spreader 4 into a gaseous state. The vapor then flows through the flow path in the heat spreader 4 to the cold end of 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, achieving defrosting. In this way, the heat exchange efficiency between the evaporator 10 and the outside world can be improved during the defrosting process, thereby improving the defrosting efficiency.

[0052] The fin group 3 is connected between the adjacent heat exchange tube group 2 and the vapor chamber 4. In the specific implementation of this embodiment, the vapor chamber 4 is connected below the heat exchange tube group 2, and the fin group 3 is connected below the vapor chamber 4. The vapor chamber 4, the heat exchange tube group 2, and the fin group 3 can all be connected by welding. The connection method between the vapor chamber 4, the heat exchange tube group 2, and the fin group 3 is not specifically limited.

[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, there is no specific restriction 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 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.

[0055] It is understandable that the inlet and outlet ends of the first heat exchange tube 21A are connected to the first liquid distributor 11A and the first liquid collector 12A, respectively, and the inlet and outlet ends of the second heat exchange tube 21B are connected to the second liquid distributor 11B and the second liquid collector 12B, respectively. 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. In other words, 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 arrangement of the pipelines, it is also possible 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] To improve the structural compactness of the evaporator 10 and enable simultaneous connection of the vapor chamber 4 to the two heat exchange tubes 21, 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. This allows for connection between the vapor chamber 4 and the first heat exchange tube 21A and the second heat exchange tube 21B, resulting in better heat exchange performance for the evaporator 10 provided in this embodiment.

[0057] See Figures 3 to 5 , Figure 3 This is a schematic diagram of the partial structure of the heat pump system provided in an embodiment of the present application. Figure 4 This is a schematic diagram of the flow direction of the working medium of the heat pump system provided in the embodiment of the present application in the heating mode. Figure 5 A schematic diagram of the flow direction of the working medium in the defrost mode of the heat pump system provided in an embodiment of the present application. As shown in the figure, this 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. The heat pump system has a first operating mode and a second operating mode. The first operating mode here can be understood as a heating mode, and the second operating mode here can be understood as a defrost mode.

[0058] Specifically, such as Figure 4As shown, when the heat pump system is in the first working mode, that is, 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, that is, the defrosting 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; 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 from the second liquid distribution pipe 11B into the second heat exchange pipe 21B, and then flows out through the second liquid collection pipe 12B, and then flows into the first heat exchange pipe 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 this 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 heating mode, this is to prevent part of the working fluid from flowing directly into the evaporator 10; in 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 provided on the first circulation loop 50; when the heat pump system is in heating mode, the first stop valve 140 is closed, connecting the compressor 20 and the gas cooler 30; when the heat pump system is in defrosting mode, the first stop valve 140 is opened;

[0063] Second shutoff valve 120 is disposed on second circulation loop 60. When the heat pump system is in the first operating mode, second shutoff valve 120 is open. When the heat pump system is in the second operating mode, second shutoff valve 120 is closed, connecting compressor 20 with second liquid distribution pipe 11B. Thus, the arrangement of first shutoff valve 140 and second shutoff valve 120 ensures that, in heating mode, the high-temperature, high-pressure gas flowing out of compressor 20 flows entirely to gas cooler 30. In defrosting mode, the high-temperature, high-pressure gas flowing out of compressor 20 flows entirely to evaporator 10.

[0064] To ensure that the compressor 20 has a relatively stable return air superheat and to regulate the flow rate of the working fluid in heating mode, the heat pump system provided in this embodiment may further include a throttle valve 110. When the heat pump system is in heating mode, the throttle valve 110 is connected between the cooling module 41 and the evaporator 10. When the heat pump system is in defrost 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 located in both the first circulation loop 50 and the second circulation loop 60, and in defrost mode, by regulating the flow rate of the working fluid, the compressor 20 can maintain a relatively stable return air superheat.

[0065] Furthermore, the heat pump system provided in this embodiment also includes a regulating valve 80; the regulating valve 80 is disposed on the second circulation loop 60. When the heat pump system is in the second operating mode, the regulating valve 80 connects the compressor 20 and the liquid distribution pipe 11B. Thus, the provision of the regulating valve 80 allows for appropriate regulation of the amount of high-temperature, high-pressure gas flowing through the second circulation loop 60, thereby maintaining a stable exhaust superheat of the compressor 20 while improving defrost efficiency.

[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 providing 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 providing the gas-liquid separator 90, it is possible to maintain a relatively stable return gas superheat in the compressor 20, so that the compressor 20 maintains a good performance.

[0068] Furthermore, to prevent backflow of the working medium in the second circulation loop 60, the heat pump system provided in this embodiment further includes a one-way valve 130, which is disposed on the second circulation loop 60. When the heat pump system is in the second operating mode, the one-way valve 130 connects the second manifold 12B with the throttle valve 110. In other words, the one-way valve 130 is located upstream of the throttle valve 110. Thus, the provision of the one-way valve 130 can prevent backflow of the working medium to a certain extent, allowing the heat pump system provided in this embodiment to perform normal defrosting operation.

[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. The CO2 flows through the compressor 20 and is compressed into high-temperature and high-pressure gas, and then flows into the gas cooler 30; in the gas cooler 30, the CO2 is isobarically cooled to a low-temperature state; then the CO2 is further cooled in the cooling module 41 of the regenerator 40 to reach a lower temperature. 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. At the same time, 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 medium 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. The separated gas enters the inlet of the compressor 20, thus 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 to exchange heat 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, the high-temperature CO2 in the gas cooler 30 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 transformations made based on the contents of the present application specification 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 distribution pipe and a first liquid collection pipe, and the second liquid pipe assembly includes a second liquid distribution pipe and a second liquid collection pipe; a plurality of heat exchange tube groups spaced apart from each other, each heat exchange tube group 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 being respectively connected to the first liquid distributor and the first liquid header, and the inlet end and the outlet end of the second heat exchange tube being respectively connected to the second liquid distributor and the second liquid header; a plurality of vapor chambers, wherein one vapor chamber is provided corresponding to one heat exchange tube group, and the cold end and the hot end of the vapor chamber are respectively connected to the first heat exchange tube and the second heat exchange tube in the corresponding heat exchange tube group; and A plurality of fin groups are provided, wherein one fin group is connected between adjacent heat exchange tube groups and the heat spreader.

2. The evaporator according to claim 1, wherein 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 pipe and the second liquid distributing pipe are located on the same side, and the first liquid collecting pipe and the second liquid collecting pipe 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 spaced apart are formed in each of the first heat exchange tube and the second heat exchange tube.

5. A heat pump system, characterized in that: comprising a compressor, a gas cooler, a regenerator and the evaporator according to 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 operating mode, the compressor, the gas cooler, the cooling module, the evaporator, and the return gas main 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 operating 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 connects 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 a first operating 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 operating 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 operating 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 shut-off valve is disconnected.

10. The heat pump system according to claim 5 or 6, characterized in that: Also included is a second stop valve, which is disposed 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 to connect the compressor and 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, 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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