Refrigerating system and testing equipment

Abstract

The utility model relates to a refrigeration system and test equipment. The refrigeration system comprises a first refrigeration module. The first refrigeration module comprises a first compressor, a first condenser, a first main expansion device and a load evaporator which are sequentially located on a first circulation loop. The first refrigeration module further comprises a cooling branch, a first bypass expansion device, a defrosting branch and a first control valve. The cooling branch is communicated between the input end of the first main expansion device and the output end of the load evaporator, and the first bypass expansion device is located on the cooling branch. The defrosting bypass communicates between the exhaust end of the first compressor and the input end of the load evaporator, and the first control valve is located on the defrosting bypass. The refrigerating system has a defrosting mode, and in the defrosting mode, the first control valve and the first bypass expansion device are opened, and the first main expansion device is closed. According to the technical scheme, the defrosting efficiency is high, and the utilization rate of the refrigerating system is increased.

Description

Technical Field

[0001] This application relates to the field of refrigeration technology, and in particular to refrigeration systems and testing equipment. Background Technology

[0002] When a refrigeration system operates at low temperatures, the surface of its load evaporator is prone to frost formation, which not only affects heat transfer but also increases the energy consumption of the refrigeration system and reduces its COP.

[0003] Currently, most refrigeration systems use electric heating for defrosting. In this mode, the refrigeration system needs to be shut down first, and after a series of purging and defrosting operations, it needs to be restarted. This method results in low utilization efficiency of the refrigeration system. Utility Model Content

[0004] Therefore, it is necessary to provide a refrigeration system and testing equipment to address the issue that using electric heating to defrost the load evaporator of a refrigeration system can affect the utilization rate of the refrigeration system.

[0005] In a first aspect, this application provides a refrigeration system, the refrigeration system including a first refrigeration module, the first refrigeration module including:

[0006] The first compressor, the first condenser, the first main expansion unit, and the load evaporator are located sequentially in the first circulation loop;

[0007] A cooling branch and a first bypass expansion device are connected between the input end of the first main expansion device and the output end of the load evaporator, with the first bypass expansion device located in the cooling branch; and

[0008] A defrost bypass and a first control valve are connected between the discharge end of the first compressor and the input end of the load evaporator, with the first control valve located in the defrost bypass;

[0009] The refrigeration system has a defrost mode, in which the first control valve and the first bypass expansion device are opened, and the first main expansion device is closed.

[0010] In some embodiments, the refrigeration system further has a cooling mode in which the first control valve is closed and the first bypass expansion device and the first main expansion device are turned on.

[0011] In some embodiments, the first control valve includes a second bypass expansion device disposed in the defrost bypass.

[0012] In some embodiments, the first refrigeration module further includes an exhaust temperature sensor disposed in the first circulation loop and located at the exhaust end of the first compressor.

[0013] In some embodiments, the first refrigeration module further includes an outlet liquid temperature sensor disposed in the first circulation loop and located at the input end of the load evaporator; one end of the defrost bypass is connected to the first circulation loop located between the outlet liquid temperature sensor and the first main expansion device.

[0014] In some embodiments, the first refrigeration module further includes a liquid outlet shut-off valve disposed in the first circulation loop. The liquid outlet shut-off valve is located at the input end of the load evaporator, and one end of the defrost bypass is connected to the first circulation loop located between the liquid outlet shut-off valve and the first main expansion device.

[0015] And / or, the first refrigeration module further includes a return gas shut-off valve, which is disposed in the first circulation loop and located at the output end of the load evaporator, and one end of the cooling branch is connected between the first compressor and the return gas shut-off valve.

[0016] In some embodiments, the first refrigeration module further includes an oil separator disposed in the first circulation loop and located between the first compressor and the first condenser; one end of the defrost bypass is connected to the discharge end of the first compressor via the oil separator.

[0017] In some embodiments, the refrigeration system further includes:

[0018] The second refrigeration module includes a second compressor, a second condenser, a second main expansion valve, and a condenser-evaporator, which are sequentially located on the second circulation loop. The condenser-evaporator serves as the first condenser and provides thermal coupling between the first circulation loop and the second circulation loop.

[0019] Secondly, this application provides a testing device, including a testing terminal and a refrigeration system as described in any of the above embodiments, wherein the load evaporator is used to regulate the temperature of the testing terminal.

[0020] In some embodiments, the testing equipment further includes an identification device for identifying whether the load evaporator is frosted.

[0021] In the aforementioned refrigeration system and its testing equipment, when frost forms on the load evaporator, the system automatically switches to defrost mode. In this mode, the first compressor in the first refrigeration module continues to operate without needing to be shut down. When the system switches back to refrigeration mode, the first compressor does not need to be restarted. Compared with traditional electric heating defrosting methods, the technical solution proposed in this application not only has higher defrosting efficiency but also enhances the overall utilization rate of the refrigeration system. Attached Figure Description

[0022] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiments below. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0023] Figure 1 This is a schematic diagram of the composition of a refrigeration system according to some embodiments of this application.

[0024] Figure 2 This is a schematic diagram of the composition of a refrigeration system according to other embodiments of this application.

[0025] The reference numerals in the detailed embodiments are as follows:

[0026] 100. Refrigeration system; 10. First refrigeration module; S1. First circulation loop; 11. First compressor; 12. First condenser; 13. First main expansion device; 14. Load evaporator; L1. Cooling branch; 15. First bypass expansion device; L2. Defrost bypass; 16. First control valve; 16a. Second bypass expansion device; T1. Exhaust temperature sensor; T2. Liquid outlet temperature sensor; J1. Liquid outlet shut-off valve; J2. Gas return shut-off valve; 17. Oil separator; 20. Second refrigeration module; S2. Second circulation loop; 21. Second compressor; 22. Second condenser; 23. Second main expansion device; 24. Condenser-evaporator. Detailed Implementation

[0027] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0028] In the description of this application, it should be understood that, where they appear, the terms “center,” “longitudinal,” “lateral,” “length,” “width,” “thickness,” “upper,” “lower,” “front,” “rear,” “left,” “right,” “vertical,” “horizontal,” “top,” “bottom,” “inner,” “outer,” “clockwise,” “counterclockwise,” “axial,” “radial,” and “circumferential” indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0029] Furthermore, where applicable, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0030] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," "fixing," etc., shall be interpreted broadly. For example, they may refer to a fixed connection, a detachable connection, or an integral part; they may refer to a mechanical connection or an electrical connection; they may refer to a direct connection or an indirect connection through an intermediate medium; they may refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0031] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0032] It should be noted that, if an element is described as "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is described as "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0033] In view of the problems pointed out in the background art, this application proposes a refrigeration system that aims to improve the utilization rate of the refrigeration system while defrosting the load evaporator of the refrigeration system.

[0034] Figure 1 This is a schematic diagram illustrating the composition of a refrigeration system 100 as shown in some embodiments. (Refer to...) Figure 1The refrigeration system 100 provided in this application embodiment includes a first refrigeration module 10. The first refrigeration module 10 includes a first compressor 11, a first condenser 12, a first main expansion device 13, and a load evaporator 14, sequentially located in a first circulation loop S1. The first refrigeration module 10 also includes a cooling branch L1, a first bypass expansion device 15, a defrost branch, and a first control valve 16. The cooling branch L1 connects the input end of the first main expansion device 13 and the output end of the load evaporator 14, and the first bypass expansion device 15 is located in the cooling branch L1. The defrost bypass L2 connects the discharge end of the first compressor 11 and the input end of the load evaporator 14, and the first control valve 16 is located in the defrost bypass L2. The refrigeration system 100 has a defrost mode; in the defrost mode, the first control valve 16 and the first bypass expansion device 15 are open, and the first main expansion device 13 is closed.

[0035] The first main expansion device 13 and the first bypass expansion device 15 can be conventional expansion valves, throttle valves, etc., or they can be composed of a combination of solenoid valves and capillary tubes. The specific configuration is not limited.

[0036] The refrigeration system 100 has a standard refrigeration mode. In this mode, the first refrigeration module 10 is started. Specifically, the first control valve 16 and the first bypass expansion device 15 are closed, the first main expansion device 13 is open, and the first compressor 11 is started. At this time, the high-temperature gaseous refrigerant discharged from the first compressor 11 is condensed into liquid as it flows through the first condenser 12, and then throttled and cooled by the first main expansion device 13, becoming a low-temperature liquid refrigerant. The low-temperature liquid refrigerant absorbs external heat in the load evaporator 14, transforming into a medium-temperature gaseous refrigerant, and finally flows back to the first compressor 11.

[0037] When frost forms on the load evaporator 14, the refrigeration system 100 enters defrost mode. Specifically, the first control valve 16 and the first bypass expansion device 15 switch from closed to open, while the first main expansion device 13 switches from open to closed. Simultaneously, the first compressor 11 continues to operate. At this time, the high-temperature liquid refrigerant discharged from the first compressor 11 is split into two paths. One path of high-temperature refrigerant flows directly to the inlet of the load evaporator 14 through the defrost bypass L2, thereby increasing its temperature to melt the frost. The other path of high-temperature refrigerant first passes through the first condenser 12 for condensation and cooling, then further throttles and cools through the first bypass expansion device 15, and finally flows through the cooling branch L1 to the outlet of the load evaporator 14, bypassing the load evaporator 14 itself. This avoids a temperature conflict with the high-temperature refrigerant entering the evaporator, effectively improving the utilization rate of the refrigerant's heat and enhancing the defrosting efficiency of the load evaporator 14.

[0038] In defrost mode, the first compressor 11 in the first refrigeration module 10 continues to run and does not need to be turned off. When the refrigeration system 100 switches back to refrigeration mode, the first compressor 11 does not need to be restarted. Compared with the traditional electric heating defrosting method, the technical solution provided in this application embodiment has higher defrosting efficiency and improves the overall utilization rate of the refrigeration system.

[0039] There are several methods to determine whether the load evaporator 14 is frosted. Specifically, an image sensor and / or a temperature sensor can be installed on the load evaporator 14. The controller of the refrigeration system 100 can acquire internal image information of the load evaporator 14 through the image sensor to determine whether frosting has occurred; simultaneously, the controller can also monitor the surface temperature of the load evaporator 14 through the temperature sensor and determine the frosting status based on temperature changes. Alternatively, manual observation can be used to determine whether the load evaporator 14 is frosted, and the refrigeration system 100 can be manually controlled to enter defrost mode.

[0040] In some embodiments, the refrigeration system 100 also has a cooling mode, in which the first control valve 16 is closed and the first bypass expansion device 15 and the first main expansion device 13 are turned on.

[0041] Specifically, when the return gas temperature and / or discharge temperature of the first compressor 11 increases, or when the external cooling capacity decreases, the refrigeration system 100 switches to cooling mode. In this mode, the first control valve 16 closes, while the first bypass expansion device 15 and the first main expansion device open.

[0042] At this point, the medium-temperature liquid refrigerant discharged from the first condenser 12 will be divided into two parts. One part of the refrigerant, after being throttled and cooled by the first main expansion device, flows into the load evaporator 14 to absorb external heat; the other part of the refrigerant, after being throttled and cooled by the first bypass expansion device 15, mixes with the high-temperature gaseous refrigerant discharged from the load evaporator 14. This mixing helps to reduce the temperature of the refrigerant returning to the first compressor 11, thereby reducing its discharge temperature and extending the service life of the first compressor 11.

[0043] In some embodiments, refer to Figure 1 The first control valve 16 includes a second bypass expansion device 16a, which is located in the defrost bypass L2.

[0044] When the refrigeration system 100 enters the defrost mode, the second bypass expansion device 16a will be turned on. It can moderately cool the high-temperature gaseous refrigerant flowing through the defrost bypass L2, so as to prevent the refrigerant temperature flowing back to the first compressor 11 from being too high and extend the service life of the first compressor 11.

[0045] Specifically, the second bypass expansion device 16a can be a conventional expansion valve, throttle valve, or a combination of a solenoid valve and a capillary tube; there are no specific limitations.

[0046] In defrost mode, the refrigerant discharged from the self-loaded evaporator 14 mixes with the liquid refrigerant flowing out of the cooling branch L1 before returning to the first compressor 11. To reduce liquid slugging during return gas from the first compressor 11, the flow rate of the defrost bypass L2 can be adjusted by controlling the opening of the second bypass expansion device 16a, thereby adjusting the temperature of the refrigerant discharged from the self-loaded evaporator 14 and reducing the liquid component in the mixed refrigerant.

[0047] In some embodiments, refer to Figure 1 The first refrigeration module 10 also includes an exhaust temperature sensor T1, which is located in the first circulation loop S1 and at the exhaust end of the first compressor 11.

[0048] Excessive exhaust temperature will shorten the lifespan of the compressor. Specifically, an exhaust temperature sensor T1 is installed at the exhaust end of the first compressor 11. The exhaust temperature sensor T1 is used to sense the exhaust temperature of the first compressor 11. If the exhaust temperature of the first compressor 11 is too high, the refrigeration system 100 can be controlled to enter the cooling mode to cool down the first compressor 11.

[0049] In some embodiments, refer to Figure 1 The first refrigeration module 10 also includes a liquid outlet temperature sensor T2, which is located in the first circulation loop S1 and at the input end of the load evaporator 14. One end of the defrost bypass L2 is connected to the first circulation loop S1 located between the liquid outlet temperature sensor T2 and the first main expansion device 13.

[0050] The outlet temperature sensor T2 is used to sense the temperature of the refrigerant entering the load evaporator 14. This temperature is used to control the cooling capacity of the load evaporator 14. When the refrigeration system 100 is in cooling mode, especially under high-temperature conditions, the cooling capacity required by the load evaporator 14 is relatively small. If the outlet temperature sensor T2 detects that the temperature of the refrigerant entering the load evaporator 14 is low, the first control valve 16 can be opened to allow some of the high-temperature refrigerant to mix with the low-temperature refrigerant discharged from the first main expansion device 13, thereby reducing the temperature of the refrigerant entering the load evaporator 14. In order to achieve the set outlet temperature, while maintaining the opening of the first main expansion device 13, the opening of the first control valve 16 is dynamically adjusted according to the temperature value detected by the outlet temperature sensor T2.

[0051] In some embodiments, refer to Figure 1The first refrigeration module 10 also includes a liquid outlet shut-off valve J1, which is located in the first circulation loop S1. The liquid outlet shut-off valve J1 is located at the input end of the load evaporator 14, and one end of the defrost bypass L2 is connected to the first circulation loop S1 located between the liquid outlet shut-off valve J1 and the first main expansion device 13.

[0052] The liquid outlet shut-off valve J1 can open or close the flow path of refrigerant into the load evaporator 14. In practical applications, the refrigeration system 100 can use an external load as the load evaporator 14, and the external load can be connected to the first circulation loop S1 later. Specifically, the input end of the external load can be connected to the first circulation loop S1 through the interface of the liquid outlet shut-off valve J1. At this time, by setting one end of the defrost bypass L2 between the liquid outlet shut-off valve J1 and the first main expansion device 13, it is not necessary to consider whether the load evaporator 14 is connected to the first circulation loop S1, making it more convenient to set up the defrost bypass L2.

[0053] In some embodiments, refer to Figure 1 The first refrigeration module 10 also includes a return gas shut-off valve J2, which is located in the first circulation loop S1 and at the output end of the load evaporator 14. One end of the cooling branch L1 is connected to the first circulation loop S1 located between the first compressor 11 and the return gas shut-off valve J2.

[0054] The return gas shut-off valve J2 can open or close the flow path of refrigerant flowing from the load evaporator 14 to the first compressor 11. When the refrigeration system 100 uses an external load as the load evaporator 14, the output end of the external load can be connected to the first circulation loop S1 through the interface with the return gas shut-off valve J2. In this case, by setting one end of the cooling branch L1 between the first compressor 11 and the return gas shut-off valve J2, it is not necessary to consider whether the load evaporator 14 is connected to the first circulation loop S1, making it more convenient to set up the cooling branch L1.

[0055] It is worth noting that in defrost mode, the high-temperature refrigerant discharged from the first compressor 11 flows through the defrost bypass L2 successively through the liquid outlet shut-off valve J1, the load evaporator 14, and the return gas shut-off valve J2, allowing all three to be defrosted simultaneously. Thus, while solving the defrosting problem of the load evaporator 14, the defrosting problems of the liquid outlet shut-off valve J1 and the return gas shut-off valve J2 are also resolved.

[0056] In some embodiments, refer to Figure 1 The first refrigeration module 10 also includes an oil separator 17, which is located in the first circulation loop S1 and between the first compressor 11 and the first condenser 12. One end of the defrost bypass L2 is connected to the discharge end of the first compressor 11 via the oil separator 17.

[0057] Specifically, the input end of the defrost bypass L2 and the refrigerant outlet of the oil separator 17 are connected to the first compressor 11, so that the refrigerant entering the defrost bypass L2 is basically a high-temperature gaseous refrigerant. The lubricating oil discharged from the first compressor 11 is returned to the first compressor 11 by the separation action of the oil separator 17, and will not flow to the defrost bypass L2. This can prevent the lubricating oil from entering the first circulation loop S1 through the defrost bypass L2, thereby reducing the amount of lubricating oil lost by the first compressor 11.

[0058] Figure 2 A schematic diagram of the composition of a refrigeration system according to another embodiment is shown.

[0059] In some embodiments, refer to Figure 2 The refrigeration system 100 also includes a second refrigeration module 20, which includes a second compressor 21, a second condenser 22, a second main expansion device 23 and a condenser-evaporator 24 located sequentially on the second circulation loop S2. The condenser-evaporator 24 serves as the first condenser 12, providing thermal coupling between the first circulation loop S1 and the second circulation loop S2.

[0060] When the refrigeration system 100 is in refrigeration mode, the second compressor 21 starts and the second main expansion device 23 is turned on. The refrigerant in the second circulation loop S2, after being discharged from the second compressor 21 in a high-temperature gaseous state, is condensed into a medium-temperature liquid state by the second condenser 22, and then cooled into a low-temperature liquid state by the second main expansion device 23. Then, the refrigerant in the first circulation loop S1 is condensed and cooled in the evaporator-condenser, and finally flows back to the second compressor 21 in a gaseous state.

[0061] At this time, the second refrigeration module 20 and the first refrigeration module 10 are thermally coupled through the condenser-evaporator 24 to form a cascade system, which can improve the refrigeration capacity of the load evaporator 14 of the first refrigeration module 10, making the refrigeration system 100 more powerful and its application range wider.

[0062] It is easy to understand that when the refrigeration system 100 is in refrigeration mode, defrost mode, or cooling mode, the second refrigeration module 20 is started, that is, the second compressor 21 is started, and the second main expansion device 23 is turned on.

[0063] In other embodiments, the first condenser 12 may be air-cooled or water-cooled, and the refrigeration system 100 may be used as a single-stage system through the first refrigeration module 10.

[0064] In addition, this application embodiment also provides a testing device, including a testing terminal and a refrigeration system 100 as described in any of the above embodiments, with a load evaporator 14 used to adjust the temperature of the testing terminal. This testing device possesses the beneficial effects described in the above embodiments, which will not be elaborated here.

[0065] Typically, the testing equipment also includes a heating device, which works in conjunction with the cooling system 100 to regulate the temperature of the testing terminal. The configuration of the heating device is not specified here; please refer to standard settings.

[0066] Test equipment can be sorting test equipment, probe station equipment, aging test equipment, etc., used for performance testing of semiconductor devices such as chips or wafers. Test terminals can be test heads, test chambers, preheating trays, feed shuttles, wafer carrier trays, etc. A test chamber is a cavity structure that provides test space, and multiple chips or wafers can be stored within it. A load evaporator 14 can be arranged within the test space to regulate the test temperature. A test head is a pressure head structure that can press down against the chip, directly contacting it to regulate its temperature. A refrigerant flow path can be provided within the load evaporator 14, using refrigerant to cool the refrigerant in the flow path. The refrigerant flow path can be connected to a pipe inside the test head, regulating the temperature of the test head through the refrigerant. A preheating tray is a structure that holds the chip and regulates its temperature. A refrigerant flow path can be connected to a pipe inside the preheating tray, regulating its temperature through the refrigerant. The feed shuttle refers to the structure that transports the chip. The coolant flow path can be connected to the piping inside the feed shuttle, and the temperature of the feed shuttle is regulated by the coolant. The wafer carrier tray refers to the tray that holds the wafer by adsorption. The coolant flow path can be connected to the piping inside the wafer carrier tray, and the test temperature of the wafer is regulated by the coolant. In addition, the test pressure head, preheating tray, and wafer carrier tray can be directly used as the load evaporator 14, and their piping can be connected to the first circulation loop S1 through the return gas shut-off valve J2 and the liquid outlet shut-off valve J1.

[0067] In some embodiments, the testing equipment further includes an identification device for identifying whether the load evaporator 14 is frosted.

[0068] The testing equipment typically consists of a housing containing the test terminal and the load evaporator 14. An identification device can be mounted on the inner wall of the housing to detect whether the load evaporator 14 is frosted. Alternatively, the identification device can be mounted directly on the load evaporator 14. The type of identification device can include image sensors, temperature sensors, etc., as described above. The identification device analyzes whether the load evaporator 14 is frosted; if frosting is present, the refrigeration system 100 is controlled to enter defrost mode, achieving automatic defrosting of the refrigeration system.

[0069] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0070] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A refrigeration system, characterized in that, The refrigeration system includes a first refrigeration module (10), which includes: The first compressor (11), the first condenser (12), the first main expansion device (13) and the load evaporator (14) are located sequentially in the first circulation loop (S1); The cooling branch (L1) and the first bypass expansion device (15) are connected between the input end of the first main expansion device (13) and the output end of the load evaporator (14), and the first bypass expansion device (15) is located in the cooling branch (L1); and The defrost bypass (L2) and the first control valve (16) are connected between the exhaust end of the first compressor (11) and the input end of the load evaporator (14), and the first control valve (16) is located in the defrost bypass (L2); The refrigeration system has a defrost mode, in which the first control valve (16) and the first bypass expansion device (15) are opened, and the first main expansion device (13) is closed.

2. The refrigeration system according to claim 1, characterized in that, The refrigeration system also has a cooling mode, in which the first control valve (16) is closed and the first bypass expansion device (15) and the first main expansion device (13) are opened.

3. The refrigeration system according to claim 1, characterized in that, The first control valve (16) includes a second bypass expansion device (16a), which is located in the defrost bypass (L2).

4. The refrigeration system according to claim 1, characterized in that, The first refrigeration module (10) also includes an exhaust temperature sensor (T1), which is located in the first circulation loop (S1) and at the exhaust end of the first compressor (11).

5. The refrigeration system according to claim 1, characterized in that, The first refrigeration module (10) further includes an outlet temperature sensor (T2), which is located in the first circulation loop (S1) and at the input end of the load evaporator (14); one end of the defrost bypass (L2) is connected to the first circulation loop (S1) located between the outlet temperature sensor (T2) and the first main expansion device (13).

6. The refrigeration system according to claim 1, characterized in that, The first refrigeration module (10) further includes a liquid outlet shut-off valve (J1) located in the first circulation loop (S1). The liquid outlet shut-off valve (J1) is located at the input end of the load evaporator (14). One end of the defrost bypass (L2) is connected to the first circulation loop (S1) located between the liquid outlet shut-off valve (J1) and the first main expansion device (13). And / or, the first refrigeration module (10) further includes a return gas shut-off valve (J2), which is disposed in the first circulation loop (S1) and located at the output end of the load evaporator (14), and one end of the cooling branch (L1) is connected to the first circulation loop (S1) located between the first compressor (11) and the return gas shut-off valve (J2).

7. The refrigeration system according to claim 1, characterized in that, The first refrigeration module (10) further includes an oil separator (17), which is disposed in the first circulation loop (S1) and located between the first compressor (11) and the first condenser (12); one end of the defrost bypass (L2) is connected to the exhaust end of the first compressor (11) via the oil separator (17).

8. The refrigeration system according to claim 1, characterized in that, The refrigeration system also includes: The second refrigeration module (20) includes a second compressor (21), a second condenser (22), a second main expansion device (23) and a condenser-evaporator (24) located sequentially on the second circulation loop (S2). The condenser-evaporator (24) serves as the first condenser (12) and provides thermal coupling between the first circulation loop (S1) and the second circulation loop (S2).

9. A testing device, characterized in that, Includes a test terminal and a refrigeration system as described in any one of claims 1-8, wherein the load evaporator (14) is used to regulate the temperature of the test terminal.

10. The testing equipment according to claim 9, characterized in that, The testing equipment also includes a recognition device for identifying whether the load evaporator (14) is frosted.

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