Refrigeration system

Abstract

The application provides a refrigeration system comprising a refrigerant main flow path, a frequency converter, a first frequency converter cooling flow path and an evaporation flow path. The refrigerant main flow path comprises a compressor, at least two heat exchangers and a main flow path throttling device, the at least two heat exchangers comprising a condensation heat exchanger in a condensation working state and an evaporation heat exchanger in an evaporation state, and refrigerant output from a discharge port of the compressor sequentially passes through the condensation heat exchanger, the main flow path throttling device and the evaporation heat exchanger and then returns to a suction port of the compressor. The frequency converter is electrically connected with the compressor and comprises a shell and a power module arranged in the shell. An inlet end of the first frequency converter cooling flow path is connected with the condensation heat exchanger to cool the power module by using the refrigerant. The evaporation flow path is arranged between an outlet end of the first frequency converter cooling flow path and the evaporation heat exchanger.

Description

Technical Field

[0001] This application relates to a refrigeration system. Background Technology

[0002] The refrigeration system includes a compressor and a frequency converter used to regulate the compressor's speed. The frequency converter generates heat continuously during operation, therefore it needs to be cooled.

[0003] It should be noted that the statements in this background section only provide background information relevant to this application and do not necessarily constitute prior art. Summary of the Invention

[0004] This application provides a cooling system to improve the cooling effect on frequency converters.

[0005] The first aspect of this application provides a refrigeration system, comprising: The refrigerant main flow path includes a compressor, at least two heat exchangers and a main flow path throttling device. The at least two heat exchangers include a condensing heat exchanger in a condensing state and an evaporating heat exchanger in an evaporating state. The refrigerant output from the compressor's discharge port passes sequentially through the condensing heat exchanger, the main flow path throttling device and the evaporating heat exchanger before returning to the compressor's suction port. A frequency converter, electrically connected to a compressor, and including a housing and a power module disposed within the housing; The first frequency converter cooling flow path, the inlet end of which is connected to a condensing heat exchanger to cool the power module using refrigerant; and The evaporation flow path is located between the outlet end of the cooling flow path of the first frequency converter and the evaporative heat exchanger.

[0006] In some embodiments, at least two heat exchangers include a first heat exchanger, a second heat exchanger, and a third heat exchanger. The refrigeration system has at least two different operating modes. In different operating modes, two of the first, second, and third heat exchangers may be in a condensing state and an evaporating state, respectively. The evaporation flow path may be selectively connected to the evaporating heat exchanger in the evaporating state of the first, second, and third heat exchangers.

[0007] In some embodiments, the evaporation flow path includes at least two evaporation branches disposed between the outlet end of the first inverter cooling flow path and the evaporation heat exchanger and arranged in parallel. In different operating modes, one of the at least two evaporation branches may be configured to be connected.

[0008] In some embodiments, at least two evaporation branches include a first evaporation branch and a second evaporation branch, the first evaporation branch being connected to a third heat exchanger, and the second evaporation branch being connected to both the first and second heat exchangers.

[0009] In some embodiments, the first inverter cooling flow path includes a first input flow path segment and a second input flow path segment connected in parallel for inputting refrigerant into the inverter. The first input flow path segment is configured to be switched on and off, and a cooling throttling device is provided on the second input flow path segment.

[0010] In some embodiments, the refrigeration system further includes a second inverter cooling flow path, which is used to cool the overall environment of the internal space of the housing. The first end of the second inverter cooling flow path is connected to the condenser heat exchanger, and the second end of the second inverter cooling flow path is connected to the suction port of the compressor.

[0011] In some embodiments, the compressor includes a screw compressor.

[0012] In some embodiments, the second end of the cooling flow path of the second frequency converter is connected to the suction port of the compressor via a return flow path, and the return flow path can be switched on and off.

[0013] In some embodiments, at least two heat exchangers include a first heat exchanger, a second heat exchanger, and a third heat exchanger. The refrigeration system has a cooling mode, a heating mode, a combined cooling and heating mode, and a defrosting mode. In the cooling mode, the first heat exchanger is in a condensing state and the third heat exchanger is in an evaporating state. In the combined cooling and heating mode, the second heat exchanger is in a condensing state and the third heat exchanger is in an evaporating state. In the heating mode, the second heat exchanger is in a condensing state and the first heat exchanger is in an evaporating state. In the defrosting mode, the first heat exchanger is in a condensing state and the second heat exchanger is in an evaporating state.

[0014] In some embodiments, the refrigeration system includes a combined chilled and hot water unit, the second heat exchanger includes a hot water shell and tube, and the third heat exchanger includes a cold water shell and tube.

[0015] Based on the technical solution provided in this application, the refrigeration system includes a refrigerant main flow path, a frequency converter, a first frequency converter cooling flow path, and an evaporation flow path. The refrigerant main flow path includes a compressor, at least two heat exchangers, and a main flow path throttling device. The at least two heat exchangers include a condensing heat exchanger in a condensing state and an evaporating heat exchanger in an evaporating state. The refrigerant output from the compressor's discharge port passes sequentially through the condensing heat exchanger, the main flow path throttling device, and the evaporating heat exchanger before returning to the compressor's suction port. The frequency converter is electrically connected to the compressor and includes a housing and a power module disposed within the housing. The inlet end of the first frequency converter cooling flow path is connected to the condensing heat exchanger to cool the power module using the refrigerant. The evaporation flow path is disposed between the outlet end of the first frequency converter cooling flow path and the evaporating heat exchanger. The technical solution of this application utilizes the first frequency converter cooling flow path to specifically cool the power module of the frequency converter, thereby improving the cooling effect on the frequency converter. Furthermore, by setting an evaporation flow path between the outlet end of the first inverter's cooling flow path and the evaporator heat exchanger, the refrigerant output from the outlet end of the first inverter's cooling flow path enters the evaporator heat exchanger through the evaporation flow path to evaporate into gaseous refrigerant, and then enters the compressor through the compressor's suction port. This reduces the amount of liquid refrigerant entering the compressor, effectively preventing liquid slugging and improving the compressor's operational reliability. Reducing the amount of liquid refrigerant entering the compressor also avoids the problem of low exhaust temperature.

[0016] Other features and advantages of this application will become clear from the following detailed description of exemplary embodiments with reference to the accompanying drawings. Attached Figure Description

[0017] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments of this application and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings: Figure 1 This is a schematic diagram of the structure of a refrigeration system according to some embodiments of this application.

[0018] Figure 2 for Figure 1 The diagram shows the refrigerant flow direction of the refrigeration system in refrigeration mode.

[0019] Figure 3 for Figure 1 The diagram shows the refrigerant flow direction in a combined cooling and heating system.

[0020] Figure 4 for Figure 1 The diagram shows the refrigerant flow direction of the refrigeration system in heating mode.

[0021] Figure 5 for Figure 1The diagram shows the refrigerant flow direction of the refrigeration system in defrost mode.

[0022] 1. Compressor; 2. Oil separator; 3. Four-way valve; 4. First heat exchanger; 5. Third heat exchanger; 6. Second heat exchanger; 7. Inverter; 8. First check valve; 9. Second check valve; 10. Heating throttling device; 11. First inverter cooling flow path; 12. Second inverter cooling flow path; 121. First solenoid valve; 113. Second solenoid valve; 114. Cooling throttling device; 14. On / off valve; 15. Third solenoid valve; 16. Fourth solenoid valve; 17. Refrigeration throttling device; 18. Fifth solenoid valve; 19. Third check valve; 20. Fourth check valve; 21. Fifth check valve; 22. Sixth check valve. Detailed Implementation

[0023] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit this application or its application or use. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0024] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of this application. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following drawings denote similar items; therefore, once an item is defined in one drawing, it need not be further discussed in subsequent drawings.

[0025] For ease of description, spatial relative terms such as "above," "over," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "above" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways, and the spatial relative descriptions used herein will be interpreted accordingly.

[0026] To cool the frequency converter, some embodiments of the refrigeration system utilize medium-temperature liquid refrigerant output from a condenser heat exchanger. After cooling the frequency converter, a portion of the refrigerant flowing out of it is in liquid state. In related technologies, all of this refrigerant flowing out of the frequency converter is directly returned to the compressor's intake port. This results in excessive liquid refrigerant entering the intake port, which can easily cause liquid slugging in the compressor, affecting its reliable operation. Furthermore, excessive liquid refrigerant entering the compressor can also lead to low exhaust temperature and low exhaust superheat, causing frequent alarms and impacting the unit's operational reliability.

[0027] To address the issue of liquid slugging in the compressor caused by excessive liquid refrigerant entering the intake port, please refer to... Figures 1 to 5 The refrigeration system provided in this embodiment includes a refrigerant main flow path, a frequency converter 7, a first frequency converter cooling flow path 11, and an evaporation flow path. The refrigerant main flow path includes a compressor 1, at least two heat exchangers, and a main flow path throttling device. The at least two heat exchangers include a condensing heat exchanger in a condensing state and an evaporating heat exchanger in an evaporating state. The refrigerant output from the compressor's discharge port passes sequentially through the condensing heat exchanger, the main flow path throttling device, and the evaporating heat exchanger before returning to the compressor's suction port. The frequency converter 7 is electrically connected to the compressor 1 and includes a housing and a power module disposed within the housing. The inlet end of the first frequency converter cooling flow path 11 is connected to the condensing heat exchanger to cool the power module using the refrigerant. The evaporation flow path is disposed between the outlet end of the first frequency converter cooling flow path 11 and the evaporating heat exchanger.

[0028] refer to Figure 1 The refrigeration system in this application embodiment includes a refrigerant main flow path, which includes a compressor 1, a four-way valve 3, at least two heat exchangers, and a main flow throttling device. For example, in Figure 1In the illustrated embodiment, the refrigerant main flow path includes a first heat exchanger 4, a second heat exchanger 6, and a third heat exchanger 5. Each heat exchanger can be in either an evaporation or condensation state. The refrigerant flow direction can be switched by controlling the four-way valve 3, thereby changing the operating state of each heat exchanger and enabling switching between different operating modes such as cooling, heating, defrosting, and combined cooling and heating. The operating state of each heat exchanger differs in different operating modes. For example, in cooling mode, the first heat exchanger 4 is in a condensation state and the third heat exchanger 5 is in an evaporation state; in heating mode, the second heat exchanger 6 is in a condensation state and the first heat exchanger 4 is in an evaporation state; in combined cooling and heating mode, the second heat exchanger 6 is in a condensation state and the third heat exchanger 5 is in an evaporation state; and in defrosting mode, the first heat exchanger 4 is in a condensation state and the second heat exchanger 6 is in an evaporation state.

[0029] In embodiments not shown in the accompanying drawings, the refrigerant main flow path may further include two heat exchangers, such as a first heat exchanger and a second heat exchanger. These heat exchangers can be in either an evaporating or condensing state. For example, in cooling mode, the first heat exchanger is in a condensing state and the second heat exchanger is in an evaporating state; in heating mode, the first heat exchanger is in an evaporating state and the second heat exchanger is in a condensing state. Of course, in some other embodiments not shown in the accompanying drawings, the refrigerant main flow path may also include more than three heat exchangers; this is not a limitation.

[0030] It is evident that, regardless of whether it includes three heat exchangers, such as Figure 1 The illustrated embodiment still includes two heat exchangers. In different operating modes, each heat exchanger can switch to different operating states. The system always has at least one condensing heat exchanger in a condensing state and one evaporating heat exchanger in an evaporating state. It should be noted that the term "condensing heat exchanger" here does not refer to any specific heat exchanger; any heat exchanger in the current operating mode that is in a condensing state is considered a condensing heat exchanger. Similarly, the term "evaporating heat exchanger" here also does not refer to any specific heat exchanger; any heat exchanger in the current operating mode that is in an evaporating state is considered an evaporating heat exchanger.

[0031] The condensation state refers to the working state in which the refrigerant undergoes a condensation phase change inside the heat exchanger. In the condensation state, the refrigerant releases heat to the outside and changes from a gaseous state to a liquid state. The evaporation state refers to the working state in which the refrigerant undergoes an evaporation phase change inside the heat exchanger. In the evaporation state, the refrigerant absorbs heat from the outside and changes from a liquid state or a gas-liquid two-phase state to a gaseous state.

[0032] The refrigerant flow path in the main refrigerant flow path is as follows: The refrigerant output from the discharge port of compressor 1 passes sequentially through the condenser heat exchanger, the main flow path throttling device, and the evaporator heat exchanger before returning to the compressor suction port to complete the cycle. Specifically, the high-temperature, high-pressure gaseous refrigerant flowing out of the discharge port of compressor 1 enters the condenser heat exchanger, where it is in a condensed state, releasing heat to the outside and changing into a liquid refrigerant. The liquid refrigerant flowing out of the condenser heat exchanger enters the main flow path throttling device, where it is throttled and depressurized, becoming a low-temperature, low-pressure gas-liquid two-phase refrigerant. This gas-liquid two-phase refrigerant flows into the evaporator heat exchanger, where it is in an evaporator state, absorbing heat from the outside and evaporating into a gaseous refrigerant. Afterward, the gaseous refrigerant flows back to the suction port of compressor 1 and is recompressed by the compressor, thus continuously achieving system heat exchange.

[0033] The frequency converter 7 is electrically connected to the compressor 1. The frequency converter 7 includes a housing and a power module disposed inside the housing. The power module has a high temperature and includes at least one of an IGBT (Insulated Gate Bipolar Transistor) power module, a rectifier module, and an inverter module.

[0034] refer to Figure 1 The inlet end of the first inverter cooling flow path 11 is connected to the condensing heat exchanger to cool the power module using the medium-temperature refrigerant output from the condensing heat exchanger. In the technical solution of this application embodiment, after cooling the power module, the refrigerant flows out through the outlet end of the first inverter cooling flow path 11 and flows into the evaporating heat exchanger through the evaporating flow path, so that this part of the refrigerant evaporates in the evaporating heat exchanger to become gaseous refrigerant, and then returns to the suction port of the compressor. In other words, the technical solution of this application embodiment uses the refrigerant used to cool the power module to enter the evaporating heat exchanger of the main refrigerant flow path for evaporation before returning to the suction port of the compressor.

[0035] The technical solution of this application embodiment utilizes the first inverter cooling flow path 11 to specifically cool the power module of the inverter 7, thereby improving the cooling effect of the inverter. Furthermore, by setting an evaporation flow path between the outlet end of the first inverter cooling flow path 11 and the evaporative heat exchanger, the refrigerant output from the outlet end of the first inverter cooling flow path 11 enters the evaporative heat exchanger through the evaporation flow path to evaporate into gaseous refrigerant, and then enters the compressor through the compressor's suction port. This reduces the amount of liquid refrigerant entering the compressor, effectively preventing liquid slugging and improving the compressor's operational reliability. Moreover, reducing the amount of liquid refrigerant entering the compressor also avoids the problem of low exhaust temperature.

[0036] In some embodiments, at least two heat exchangers include a first heat exchanger 4, a second heat exchanger 6, and a third heat exchanger 5. The refrigeration system has at least two different operating modes. In different operating modes, two of the first heat exchangers 4, the second heat exchanger 6, and the third heat exchanger 5 may be in a condensing state and an evaporating state, respectively. The evaporation flow path may be selectively connected to the heat exchanger in the evaporating state among the first heat exchanger, the second heat exchanger, and the third heat exchanger.

[0037] Still for reference Figure 1 As described above, at least two heat exchangers include a first heat exchanger 4, a second heat exchanger 6, and a third heat exchanger 5. In cooling mode, the first heat exchanger 4 is in a condensing state, and the third heat exchanger 5 is in an evaporating state; in heating mode, the second heat exchanger 6 is in a condensing state, and the first heat exchanger 4 is in an evaporating state; in combined cooling and heating mode, the second heat exchanger 6 is in a condensing state, and the third heat exchanger 5 is in an evaporating state; in defrosting mode, the first heat exchanger 4 is in a condensing state, and the second heat exchanger 6 is in an evaporating state. The heat exchangers in the evaporating state may differ in different operating modes. Of course, in other embodiments not shown in the accompanying drawings, the operating states of the aforementioned heat exchangers may differ in different operating modes.

[0038] The evaporation flow path of this application embodiment can be selectively connected to the heat exchanger in the evaporation state among the first, second, and third heat exchangers. In this way, regardless of the operating mode, the refrigerant flowing out from the outlet end of the first inverter cooling flow path 11 can flow through the evaporation flow path to the heat exchanger in the evaporation state in that operating mode for evaporation heat exchange. In this way, the liquid refrigerant can be transformed into gaseous refrigerant through evaporation heat exchange. Therefore, the technical solution of this application embodiment can effectively avoid liquid slugging on the compressor in different operating modes of the refrigeration system, thereby improving the operating reliability of the compressor.

[0039] To enable the evaporation flow path to selectively connect to different heat exchangers under the aforementioned different operating modes, refer to Figure 1 The evaporation flow path includes at least two evaporation branches arranged in parallel between the outlet end of the first frequency converter cooling flow path 11 and the evaporation heat exchanger. In different operating modes, one of the at least two evaporation branches may be configured to be connected.

[0040] In some embodiments, the refrigeration system includes a first heat exchanger 4, a second heat exchanger 6, and a third heat exchanger 5. In different operating modes, the three heat exchangers are in an evaporation state. In order for the refrigerant flowing out from the outlet of the first inverter cooling flow path 11 to enter the heat exchanger in the evaporation state in the corresponding operating mode for evaporation in the above different operating modes, the evaporation flow path needs to be able to communicate with the three heat exchangers respectively. In some embodiments, the evaporation flow path may include three evaporation branches connected to the three heat exchangers. In different operating modes, one of the three evaporation branches is selected to be connected so that the refrigerant enters the evaporation heat exchanger in the corresponding operating mode, while the other evaporation branches are disconnected.

[0041] exist Figure 1 In the illustrated embodiment, the evaporation flow path includes a first evaporation branch 150 and a second evaporation branch 180. The first evaporation branch 150 is connected to the third heat exchanger 5, and the second evaporation branch 180 is connected to both the first heat exchanger 4 and the second heat exchanger 6.

[0042] The first evaporation branch 150 of the technical solution of this application embodiment is connected to the third heat exchanger 5. In this way, when the third heat exchanger 5 is in the evaporation state, the refrigerant flowing out from the outlet end of the first inverter cooling flow path 11 can flow into the third heat exchanger 5 through the first evaporation branch 150 for evaporation. The second evaporation branch 180 is connected to both the first heat exchanger 4 and the second heat exchanger 6. In this way, when the first heat exchanger 4 or the second heat exchanger 6 is in the evaporation state, the refrigerant flowing out from the outlet end of the first inverter cooling flow path 11 can flow into the evaporation heat exchanger in the current working mode through the second evaporation branch 180 for evaporation.

[0043] The technical solution of this application embodiment realizes the separate connection of three heat exchangers through two evaporation branches, the first evaporation branch 150 and the second evaporation branch 180, which makes the structure of the refrigeration system simpler.

[0044] A third solenoid valve 15 is provided on the first evaporation branch 150; a fifth solenoid valve 18 is provided on the second evaporation branch 180. Either the third solenoid valve 15 or the fifth solenoid valve 18 is opened to allow either the first evaporation branch 150 or the second evaporation branch 180 to be connected.

[0045] In some embodiments, the first inverter cooling flow path 11 includes a first input flow path section 111 and a second input flow path section 112 connected in parallel for inputting refrigerant into the inverter. The first input flow path section 111 is configured to be switched on and off, and the second input flow path section 112 is provided with a cooling throttling device 114.

[0046] The first inverter cooling flow path 11 includes two input flow paths connected in parallel: a first input flow path 111 and a second input flow path 112. The second input flow path 112 is equipped with a throttling device. When the inverter operating temperature is too high, the second input flow path 112, equipped with a cooling throttling device 114, can be switched on. After the refrigerant flows through the cooling throttling device 114, it undergoes throttling and voltage reduction, further lowering its own temperature, enhancing the heat exchange and cooling effect, and quickly removing heat from the inverter housing cavity and the heat generated by the power module, effectively suppressing the temperature rise of various components.

[0047] like Figure 1 As shown, in some embodiments, the refrigeration system further includes a second inverter cooling path 12. The second inverter cooling path 12 is used to cool the overall internal space of the housing. The first end of the second inverter cooling path 12 is connected to the condenser heat exchanger, and the second end of the second inverter cooling path is connected to the compressor's suction port.

[0048] Since the inverter housing contains other components besides the power module, this embodiment utilizes a second inverter cooling path 12 specifically for cooling these other components. The second inverter cooling path 12 is distributed across other locations within the housing to dissipate heat over a larger area. Therefore, the heat absorption flow rate of the second inverter cooling path 12 is greater than that of the first inverter cooling path 11. This ensures that most of the refrigerant flowing from the second inverter cooling path 12 is converted into gaseous refrigerant through heat absorption. The remaining small amount of gaseous refrigerant enters the compressor through the compressor's suction port, also serving to dissipate heat and lubricate the compressor. Furthermore, by directly connecting the second inverter cooling path 12 (cooling the inverter housing) and the first inverter cooling path (cooling the power module) to the suction port and the evaporation heat exchanger via an evaporation path, respectively, the two cooling paths are independent, preventing inverter temperature exceeding limits due to uneven liquid distribution.

[0049] Compressor 1 includes a screw compressor. The screw compressor generates a large amount of heat during the compression process. Liquid refrigerant is injected into the compression chamber through the cooling flow path 12 of the second frequency converter, utilizing the latent heat of refrigerant evaporation to quickly remove the heat generated during compression by the male and female rotors. Therefore, the technical solution of this application embodiment is particularly suitable for screw compressors.

[0050] The second inverter cooling path 12 is used to cool the internal environment of the inverter housing. It absorbs heat from all auxiliary components within the housing, including reactors, control circuit boards, and bus capacitors, as well as residual heat dissipated into the air inside the cabinet by the power module. It has a large heat exchange area. The first inverter cooling path 11 only directly absorbs heat generated by the power module; its heat exchange area is limited to the power module itself, resulting in a smaller heat exchange area. Overall, the second inverter cooling path 12 bears a higher total heat load than the first inverter cooling path 11, meaning the second inverter cooling path 12 absorbs more heat than the first inverter cooling path 11. Assuming the refrigerant inlet temperatures are the same for both paths, the refrigerant temperature rise in the second inverter cooling path 12 is greater, resulting in a higher outflow temperature. Therefore, the proportion of liquid refrigerant in the refrigerant flowing out of the second inverter cooling path 12 is smaller.

[0051] This application addresses this issue by directly connecting the second end of the second inverter cooling flow path 12 to the compressor's suction port, while connecting the first inverter cooling flow path 11 to the evaporation flow path. This allows the compressor to dissipate heat using a small amount of liquid refrigerant output from the second end of the second inverter cooling flow path 12, while avoiding the problem of excessive liquid refrigerant causing liquid slugging in the compressor due to the direct input of liquid refrigerant from the first inverter cooling flow path 11 into the compressor.

[0052] The second end of the second inverter cooling flow path 12 is connected to the suction port of the compressor 1 via a return flow path. The return flow path is configured to be on and off. The return flow path of the second inverter cooling flow path 12 is arranged to be on and off, and can be selectively opened or closed according to the ambient temperature and inverter load. The flow path is cut off under low temperature and low load conditions to reduce refrigerant waste and improve system energy efficiency.

[0053] like Figures 1 to 5 As shown, the main refrigerant path also includes a four-way valve 3, which has a first valve port D, a second valve port C, a third valve port E, and a fourth valve port S. The discharge port of the compressor 1 is connected to the first valve port D, the first heat exchanger 4 is connected to the second valve port C, the second heat exchanger 6 is connected to the third valve port E, the suction port of the compressor 1 is connected to the fourth valve port S, the refrigerant inlet of the third heat exchanger 5 is connected to the first heat exchanger 4 and the second heat exchanger 6, and the refrigerant outlet of the third heat exchanger 5 is connected to the air inlet of the compressor 1.

[0054] The refrigeration system has a cooling mode, a heating mode, a combined cooling and heating mode, and a defrosting mode. In cooling mode, the first heat exchanger 4 is in a condensing state, and the third heat exchanger 5 is in an evaporating state. In combined cooling and heating mode, the second heat exchanger 6 is in a condensing state, and the third heat exchanger 5 is in an evaporating state. In heating mode, the second heat exchanger 6 is in a condensing state, and the first heat exchanger 4 is in an evaporating state. In defrosting mode, the first heat exchanger 4 is in a condensing state, and the second heat exchanger 6 is in an evaporating state.

[0055] The heat exchangers in the refrigeration system of this application embodiment can switch between condensation and evaporation modes according to the system mode. This allows the three heat exchangers to switch between different modes, including cooling, heating, combined cooling and heating, and defrosting. The three heat exchangers are reused in a cycle, eliminating the need for redundant heat exchangers and simplifying the piping structure.

[0056] In some embodiments, the refrigeration system includes a combined chilled and hot water unit, the second heat exchanger 6 includes a hot water shell and tube, and the third heat exchanger 5 includes a cold water shell and tube.

[0057] The second heat exchanger 6 uses hot water shell-and-tube heat exchange, and the third heat exchanger 5 uses cold water shell-and-tube heat exchange, respectively responsible for hot and cold water heat exchange. In combined cooling and heating mode, both hot and cold water can be produced simultaneously. The water circuit is independently controlled in cooling and heating modes, ensuring stable water temperature control. Furthermore, the two shell-and-tube heat exchangers can switch between condensation and evaporation states depending on the operating mode, exhibiting high integration and reducing the number of components.

[0058] The following is based on Figures 1 to 5 The working process of the refrigeration system of a specific embodiment of this application in four different working modes will be described in detail.

[0059] like Figure 1 As shown, the refrigeration system of this embodiment includes a compressor 1, an oil separator 2, a four-way valve 3, a first heat exchanger 4, a second heat exchanger 6, a third heat exchanger 5, a frequency converter 7, a first one-way valve 8, a second one-way valve 9, a heating throttling device 10, a first frequency converter cooling flow path 11, a second frequency converter cooling flow path 12, a first solenoid valve 121, a second solenoid valve 113, a cooling throttling device 114, an on / off valve 14, a third solenoid valve 15, a fourth solenoid valve 16, a refrigeration throttling device 17, a fifth solenoid valve 18, a third one-way valve 19, a fourth one-way valve 20, a fifth one-way valve 21, and a sixth one-way valve 22.

[0060] The first heat exchanger 4 is a finned heat exchanger, the second heat exchanger 6 is a hot water shell and tube, and the third heat exchanger 5 is a cold water shell and tube. The heating throttling device 10 includes a heating expansion valve, the cooling throttling device 17 includes a cooling expansion valve, and the cooling throttling device 114 includes a cooling expansion valve.

[0061] The four-way valve 3 has a first valve port D, a second valve port C, a third valve port E, and a fourth valve port S. The exhaust port of the compressor 1 is connected to the first valve port D. The first heat exchanger 4 is connected to the second valve port C. The second heat exchanger 6 is connected to the third valve port E. The suction port of the compressor 1 is connected to the fourth valve port S. The refrigerant inlet of the third heat exchanger 5 is connected to the first heat exchanger 4 and the second heat exchanger 6. The refrigerant outlet of the third heat exchanger 5 is connected to the air inlet of the compressor 1.

[0062] An on / off valve 14 is installed on the return flow path. A third solenoid valve 15 is installed on the first evaporation branch; a fifth solenoid valve 18 is installed on the second evaporation branch.

[0063] Figure 2 This diagram illustrates the refrigerant flow direction of the refrigeration system in cooling mode according to this embodiment.

[0064] like Figure 2 As shown by the arrows, the main refrigerant flow path is: compressor 1 → oil separator 2 → four-way valve 3 (DC port) → first heat exchanger 4 → second check valve 9 → fourth solenoid valve 16 → refrigeration throttling device 17 → third heat exchanger 5 → fifth check valve 21 → compressor 1.

[0065] Heating throttling device 10 is closed; on / off valve 14 is open; third solenoid valve 15 is open; fourth solenoid valve 16 is open; fifth solenoid valve 18 is closed.

[0066] The first heat exchanger 4 is in a condensation state, and the third heat exchanger 5 is in an evaporation state.

[0067] like Figure 2 As shown by the red line, the inverter cooling flow path is as follows: the refrigerant enters the inverter 7 through the first inverter cooling flow path 11 to cool the inside of the casing, and the cooled refrigerant returns directly to the suction port of the compressor 1 through the return flow path; the refrigerant enters the inverter 7 through the second inverter cooling flow path 12 to cool the power module, and the cooled refrigerant enters the third heat exchanger 5 through the first evaporation branch for evaporation.

[0068] Figure 3 This diagram illustrates the refrigerant flow direction of the refrigeration system in this embodiment when it is in combined cooling and heating mode.

[0069] like Figure 3 As shown by the arrows, the main refrigerant flow path is: compressor 1 → oil separator 2 → four-way valve 3 (DE port) → second heat exchanger 6 → fourth check valve 20 → fourth solenoid valve 16 → refrigeration throttling device 17 → third heat exchanger 5 → fifth check valve 21 → compressor 1.

[0070] Heating throttling device 10 is closed; fifth solenoid valve 18 is closed.

[0071] The second heat exchanger 6 is in a condensation state, and the third heat exchanger 5 is in an evaporation state.

[0072] like Figure 2 As shown by the red line, the inverter cooling flow path is as follows: the refrigerant enters the inverter 7 through the first inverter cooling flow path 11 to cool the inside of the casing, and the cooled refrigerant returns directly to the suction port of the compressor 1 through the return flow path; the refrigerant enters the inverter 7 through the second inverter cooling flow path 12 to cool the power module, and the cooled refrigerant enters the third heat exchanger 5 through the first evaporation branch for evaporation.

[0073] Figure 4 This diagram illustrates the refrigerant flow direction of the refrigeration system in heating mode according to this embodiment.

[0074] like Figure 4 As shown by the arrows, the main refrigerant flow path is: compressor 1 → oil separator 2 → four-way valve 3 (DE port) → second heat exchanger 6 → fourth check valve 20 → heating throttling device 10 → first check valve 8 → first heat exchanger 4 → four-way valve (CS port) → sixth check valve 22 → compressor 1.

[0075] The refrigeration throttling device 17 is closed, and the third solenoid valve 15 and the fourth solenoid valve 16 are closed.

[0076] The second heat exchanger 6 is in a condensation state, and the first heat exchanger 4 is in an evaporation state.

[0077] like Figure 2 As shown by the red line, the inverter cooling flow path is as follows: the refrigerant enters the inverter 7 through the first inverter cooling flow path 11 to cool the inside of the housing, and the cooled refrigerant returns directly to the suction port of the compressor 1 through the return flow path; the refrigerant enters the inverter 7 through the second inverter cooling flow path 12 to cool the power module, and the cooled refrigerant enters the first heat exchanger 4 through the second evaporation branch to evaporate.

[0078] Figure 5 This diagram illustrates the refrigerant flow direction of the refrigeration system in defrost mode according to this embodiment.

[0079] like Figure 5 As shown by the arrows, the main refrigerant flow path is: compressor 1 → oil separator 2 → four-way valve 3 (DC port) → first heat exchanger 4 → second check valve 9 → heating throttling device 10 → third check valve 19 → second heat exchanger 6 → four-way valve (ES port) → sixth check valve 22 → compressor 1.

[0080] The refrigeration throttling device 17 is closed, and the third solenoid valve 15 and the fourth solenoid valve 16 are closed.

[0081] The first heat exchanger 4 is in a condensation state, and the second heat exchanger 6 is in an evaporation state.

[0082] like Figure 2 As shown by the red line, the inverter cooling flow path is as follows: the refrigerant enters the inverter 7 through the first inverter cooling flow path 11 to cool the inside of the casing, and the cooled refrigerant returns directly to the suction port of the compressor 1 through the return flow path; the refrigerant enters the inverter 7 through the second inverter cooling flow path 12 to cool the power module, and the cooled refrigerant enters the second heat exchanger 6 through the second evaporation branch to evaporate.

[0083] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application and not to limit them; although this application has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications can still be made to the specific implementation of this application or equivalent substitutions can be made to some technical features without departing from the spirit of the technical solutions of this application, and all such modifications and substitutions should be covered within the scope of the technical solutions claimed in this application.

Claims

1. A refrigeration system, characterized in that, include: The refrigerant main flow path includes a compressor (1), at least two heat exchangers and a main flow path throttling device. The at least two heat exchangers include a condensing heat exchanger in a condensing state and an evaporating heat exchanger in an evaporating state. The refrigerant output from the exhaust port of the compressor passes through the condensing heat exchanger, the main flow path throttling device and the evaporating heat exchanger in sequence and then returns to the suction port of the compressor. The inverter (7) is electrically connected to the compressor (1) and includes a housing and a power module disposed within the housing; The first inverter cooling flow path (11) is connected to the condenser heat exchanger to cool the power module using refrigerant. and An evaporation flow path is located between the outlet end of the first inverter cooling flow path (11) and the evaporation heat exchanger.

2. The refrigeration system according to claim 1, characterized in that, The at least two heat exchangers include a first heat exchanger (4), a second heat exchanger (6), and a third heat exchanger (5). The refrigeration system has at least two different operating modes. In different operating modes, two of the first heat exchanger (4), the second heat exchanger (6), and the third heat exchanger (5) may be in a condensing state and an evaporating state, respectively. The evaporation flow path may be selectively connected to the evaporating heat exchanger in the first heat exchanger, the second heat exchanger, and the third heat exchanger that is in the evaporating state.

3. The refrigeration system according to claim 2, characterized in that, The evaporation flow path includes at least two evaporation branches arranged in parallel between the outlet end of the first inverter cooling flow path (11) and the evaporation heat exchanger. In different operating modes, one of the at least two evaporation branches may be configured to be connected.

4. The refrigeration system according to claim 3, characterized in that, The at least two evaporation branches include a first evaporation branch (150) and a second evaporation branch (180). The first evaporation branch is connected to the third heat exchanger (5), and the second evaporation branch is connected to both the first heat exchanger (4) and the second heat exchanger (6).

5. The refrigeration system according to claim 1, characterized in that, The first inverter cooling flow path (11) includes a first input flow path section (111) and a second input flow path section (112) connected in parallel for inputting refrigerant into the inverter. The first input flow path section (111) can be switched on and off, and the second input flow path section (112) is provided with a cooling throttling device (114).

6. The refrigeration system according to any one of claims 1 to 5, characterized in that, The refrigeration system also includes a second inverter cooling flow path (12), which is used to cool the internal space of the housing as a whole. The first end of the second inverter cooling flow path (12) is connected to the condenser heat exchanger, and the second end of the second inverter cooling flow path is connected to the suction port of the compressor.

7. The refrigeration system according to claim 6, characterized in that, The compressor (1) includes a screw compressor.

8. The refrigeration system according to claim 6, characterized in that, The second end of the cooling flow path of the second frequency converter is connected to the suction port of the compressor through a return flow path, which can be switched on and off.

9. The refrigeration system according to any one of claims 1 to 5, characterized in that, The at least two heat exchangers include a first heat exchanger (4), a second heat exchanger (6), and a third heat exchanger (5). The refrigeration system has a refrigeration mode, a heating mode, a combined cooling and heating mode, and a defrosting mode. In the refrigeration mode, the first heat exchanger (4) is in a condensing state, and the third heat exchanger (5) is in an evaporating state. In the combined cooling and heating mode, the second heat exchanger (6) is in a condensing state, and the third heat exchanger (5) is in an evaporating state. In the heating mode, the second heat exchanger (6) is in a condensing state, and the first heat exchanger (4) is in an evaporating state. In the defrosting mode, the first heat exchanger (4) is in a condensing state, and the second heat exchanger (6) is in an evaporating state.

10. The refrigeration system according to claim 9, characterized in that, The refrigeration system includes a combined hot and cold water unit, the second heat exchanger (6) includes a hot water shell and tube, and the third heat exchanger (5) includes a cold water shell and tube.

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