Refrigerating system, control method thereof and testing equipment

Abstract

The invention relates to a refrigerating system, a control method thereof and testing equipment. The refrigerating system comprises a first-stage refrigerating module and a second-stage refrigerating module. The first-stage refrigeration module comprises a first-stage compressor, a condenser, a first gas-liquid separator, a first expansion valve and an evaporative condenser which are sequentially arranged on a first-stage circulation loop. The second-stage refrigeration module comprises a second-stage compressor, a second expansion valve, a second gas-liquid separator and a load evaporator which are sequentially arranged on the second-stage circulation loop, the second-stage refrigeration module and the first-stage refrigeration module share an evaporative condenser, and the evaporative condenser is located between the second-stage compressor and the second gas-liquid separator on the second-stage circulation loop. According to the technical scheme, the refrigerating capacity of the refrigerating system can be improved, and then the COP of the refrigerating system is improved.

Description

Technical Field

[0001] The present application relates to the technical field of semiconductor testing equipment, and in particular to a refrigeration system and testing equipment. Background Art

[0002] The coefficient of performance (COP) refers to the ratio of the cooling capacity of a refrigeration system to the work done by the compressor. Improving the cooling capacity of a refrigeration system is one of the effective ways to improve its COP. For a refrigeration system, if the refrigerant is not sufficiently supercooled at the condenser, then after expansion and throttling by the throttle valve, the dryness of the refrigerant will be higher, which will lead to a reduction in the available liquid refrigerant in the evaporator, resulting in a significant decrease in the system's cooling capacity, and the COP will also be reduced. Summary of the invention

[0003] Based on this, the present application provides a refrigeration system and a control method thereof, which can increase the refrigeration capacity of the refrigeration system and thereby improve the COP of the refrigeration system.

[0004] In a first aspect, the present application provides a refrigeration system, comprising:

[0005] The primary refrigeration module comprises a primary compressor, a condenser, a first gas-liquid separator, a first expansion valve and an evaporative condenser which are sequentially arranged on the primary circulation loop;

[0006] A secondary refrigeration module, comprising a secondary compressor, a second expansion valve, a second gas-liquid separator and a load evaporator which are sequentially arranged on a secondary circulation loop, wherein the secondary refrigeration module and the primary refrigeration module share the evaporative condenser, and the evaporative condenser is located between the secondary compressor and the second gas-liquid separator on the secondary circulation loop;

[0007] Among them, the refrigeration system also includes a first branch, a second branch and a heat exchanger, the first branch connects the gas outlet of the first gas-liquid separator and the inlet end of the first expansion valve, the second branch connects the gas outlet of the second gas-liquid separator and the return gas end of the secondary compressor, the first branch and the second branch both pass through the heat exchanger and exchange heat through the heat exchanger.

[0008] In some embodiments, the refrigeration system includes a control valve for controlling the flow rate of the flow path, and the control valve is provided on the first branch and / or the second branch.

[0009] In some embodiments, the control valve includes a first valve, a second valve, and a third valve;

[0010] The first valve is arranged on the first branch and located at the inlet side of the heat exchanger, the second valve is arranged on the second branch and located at the inlet side of the heat exchanger, and the third valve is arranged on the second branch and located at the outlet side of the heat exchanger;

[0011] The refrigeration system further includes a one-way valve disposed on the first branch and located at an outlet side of the heat exchanger.

[0012] In some embodiments, the refrigeration system includes a throttling bypass and a third expansion valve;

[0013] The throttling bypass is arranged in parallel with the secondary circulation loop and is connected between the exhaust end of the secondary compressor and the inlet end of the load evaporator. The third expansion valve is arranged on the throttling bypass.

[0014] In some embodiments, the refrigeration system includes a first temperature sensor, which is disposed in the secondary circulation loop and located between an outlet of the throttling bypass and an inlet end of the load evaporator.

[0015] In a second aspect, the present application provides a control method for a refrigeration system, which is applied to the refrigeration system described in any of the above embodiments, and the control method includes:

[0016] Acquiring a refrigeration demand parameter, and determining an operating mode of the refrigeration system according to the refrigeration demand parameter;

[0017] When it is determined that the working mode of the refrigeration system is the large refrigeration working mode, the primary refrigeration module and the secondary refrigeration module are enabled, and the first branch and the second branch are connected.

[0018] In some embodiments, after determining the working mode of the refrigeration system according to the refrigeration demand parameter, the method further includes:

[0019] When it is determined that the working mode of the refrigeration system is the small refrigeration working mode, the primary refrigeration module and the secondary refrigeration module are enabled, the first branch and the second branch are cut off, and the throttling bypass is turned on;

[0020] Accordingly, when it is determined that the working mode of the refrigeration system is the large refrigeration working mode, the method further includes: cutting off the throttling bypass;

[0021] The throttling bypass is arranged in parallel with the secondary circulation loop and is connected between the exhaust end of the secondary compressor and the inlet end of the load evaporator, and the third expansion valve is arranged in the throttling bypass.

[0022] In some embodiments, the refrigeration demand parameter includes at least one of a target liquid outlet temperature Tc, a target load temperature Tf, a device operating state parameter, and an actual load temperature Ts;

[0023] The determining the working mode of the refrigeration system according to the refrigeration demand parameter comprises:

[0024] When t3≤Tc≤t2<0, or Tf>t1>0 and the equipment operation state parameter is a high temperature test condition parameter, or Ts>t1 and Tf<t2 are satisfied, it is determined that the working mode of the refrigeration system is a large refrigeration working mode;

[0025] Among them, t1, t2 and t3 are all preset temperatures.

[0026] In some embodiments, the refrigeration demand parameter includes the target liquid outlet temperature Tc;

[0027] The determining the working mode of the refrigeration system according to the refrigeration demand parameter comprises:

[0028] When t4≤Tc≤0 is satisfied, it is determined that the working mode of the refrigeration system is a small refrigeration working mode, wherein t4 is a preset temperature and is greater than t2.

[0029] In a third aspect, the present application also provides a testing device, comprising a test terminal, a heating element and a refrigeration system, wherein the refrigeration system and the heating element are used together to adjust the test temperature of the test terminal, and the refrigeration system is a refrigeration system as described in any of the above embodiments, or the refrigeration system can execute the control method described in any of the above embodiments.

[0030] In the above-mentioned refrigeration system and its control method and test equipment, due to the arrangement of the first branch, the second branch and the heat exchanger, during the refrigeration process, the refrigerant entering the first expansion valve is almost completely in liquid phase, which helps to reduce the dryness of the first refrigerant after the expansion throttling, and ensures that the refrigerant entering the evaporative condenser is mainly in liquid phase. The first refrigerant can provide a higher cooling capacity at the evaporative condenser, so that the second refrigerant can be more fully liquefied and cooled at the evaporative condenser, and then the second refrigerant can provide more cooling capacity to the load at the load evaporator, thereby greatly improving the COP of the refrigeration system.

[0031] Moreover, the temperature of the second refrigerant in the second branch increases after absorbing the heat of the first refrigerant in the first branch. The second refrigerant flowing out of the load evaporator mixes with it, further increasing the superheat. This process helps to increase the return air temperature of the secondary compressor, thereby reducing the risk of liquid hammer in the secondary compressor. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present application. Moreover, the same reference numerals are used throughout the drawings to represent the same components. In the drawings:

[0033] Figure 1 Schematic diagram of the composition of the refrigeration system of some embodiments.

[0034] Figure 2 Schematic diagram of the composition of refrigeration systems in other embodiments.

[0035] Figure 3 The figure is a flowchart of a control method of a refrigeration system in some embodiments.

[0036] Figure 4 Schematic diagram of the flow of control methods for refrigeration systems in other embodiments.

[0037] The reference numerals in the specific implementation manner are as follows:

[0038] 100. Refrigeration system; 10. Primary refrigeration module; L1. Primary circulation loop; 11. Primary compressor; 12. Condenser; 13. First gas-liquid separator; 14. First expansion valve; 15. Evaporative condenser; 16. First dryer; 20. Secondary refrigeration module; L2. Secondary circulation loop; 21. Secondary compressor; 22. Second expansion valve; 23. Second gas-liquid separator; 24. Load evaporator; 25. Oil separator; 26. Second dryer; z1. First branch; z2. Second branch; 30. Heat exchanger; f. Control valve; f1. First valve; f2. Second valve; f3. Third valve; s. One-way valve; z3. Throttling bypass; 40. Third expansion valve; 50. First temperature sensor. DETAILED DESCRIPTION

[0039] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0040] In the description of the present application, it should be understood that terms such as “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships, if any, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0041] In addition, if present, the terms "first" and "second" are used for descriptive purposes only and are not to be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined 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 clearly and specifically defined.

[0042] In this application, unless otherwise clearly specified and limited, if any, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0043] In the present application, if it appears, unless otherwise clearly specified and limited, a first feature “above” or “below” a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature “above”, “above” and “above” a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature “below”, “below” and “below” a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0044] It should be noted that, if present, when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used herein are for illustrative purposes only and are not intended to be the only implementation method.

[0045] In order to increase the refrigeration capacity of the refrigeration system and improve its COP, the embodiment of the present application provides a refrigeration system. The refrigeration system in the embodiment of the present application is described in detail below.

[0046] Figure 1 Schematic diagram of the composition of the refrigeration system of some embodiments.

[0047] Please refer to Figure 1 The refrigeration system 100 provided in the embodiment of the present application includes a primary refrigeration module 10 and a secondary refrigeration module 20. The primary refrigeration module 10 includes a primary compressor 11, a condenser 12, a first gas-liquid separator 13, a first expansion valve 14 and an evaporative condenser 15 which are sequentially arranged on the primary circulation loop L1. The secondary refrigeration module 20 includes a secondary compressor 21, a second expansion valve 22, a second gas-liquid separator 23 and a load evaporator 24 which are sequentially arranged on the secondary circulation loop L2. The secondary refrigeration module 20 and the primary refrigeration module 10 share the evaporative condenser 15, and the evaporative condenser 15 is located between the secondary compressor 21 and the second gas-liquid separator 23 on the secondary circulation loop L2.

[0048] Specifically, the condenser 12 has multiple options such as air cooling type and water cooling type. In practical application, the load evaporator 24 can reduce the temperature of the external load. Further, the load evaporator 24 can exchange heat with the external load through heat conduction, heat convection, etc.

[0049] The primary circulation loop L1 serves as a high-temperature refrigeration loop in the refrigeration system 100, while the secondary circulation loop L2 serves as a low-temperature refrigeration loop. The two loops exchange heat through the evaporative condenser 15, and together constitute a cascade refrigeration system. In the primary circulation loop L1, the first refrigerant flows out from the exhaust end of the primary compressor 11, flows through the condenser 12, the first gas-liquid separator 13, the first expansion valve 14 in sequence, and finally passes through the evaporative condenser 15, and then flows back to the suction end of the primary compressor 11. In the secondary circulation loop L2, the second refrigerant flows out from the exhaust end of the secondary compressor 21, flows through the evaporative condenser 15, the second expansion valve 22, the second gas-liquid separator 23 in sequence, and finally passes through the load evaporator 24, and then flows back to the suction end of the secondary compressor 21.

[0050] Among them, the refrigeration system 100 also includes a first branch z1, a second branch z2 and a heat exchanger 30. The first branch z1 connects the air outlet of the first gas-liquid separator 13 and the inlet end of the first expansion valve 14, and the second branch z2 connects the air outlet of the second gas-liquid separator 23 and the return air end of the secondary compressor 21. The first branch z1 and the second branch z2 both pass through the heat exchanger 30 and exchange heat through the heat exchanger 30.

[0051] Specifically, two flow channels are configured inside the heat exchanger 30, which are respectively used as a part of the first branch z1 and the second branch z2. When the fluid passes through the first branch z1 and the second branch z2, heat energy can be exchanged inside the heat exchanger 30. As for the type of the heat exchanger 30, a common type in the art, such as a plate type or a shell and tube type, can be adopted.

[0052] During the operation of the refrigeration system 100, when the high-temperature gas phase first refrigerant discharged from the primary compressor 11 does not reach a supercooled state in the condenser 12, the gas-liquid mixed state of the first refrigerant is separated in the first gas-liquid separator 13. The gas phase first refrigerant flows from the gas outlet of the first gas-liquid separator 13 into the first branch z1, while the liquid phase first refrigerant flows from the outlet of the first gas-liquid separator 13 to the first expansion valve 14.

[0053] At the same time, if the high-temperature gaseous second refrigerant discharged from the secondary compressor 21 is not fully cooled to a supercooled state at the evaporative condenser 15, or the expansion throttling effect of the second expansion valve 22 is not fully realized, resulting in the second refrigerant flowing out of the second expansion valve 22 having a high dryness and presenting a gas-liquid mixed phase, then when the second refrigerant flows through the second gas-liquid separator 23, the gaseous second refrigerant will flow from the outlet of the separator into the second branch z2, while the liquid second refrigerant will flow from the outlet of the separator to the load evaporator 24.

[0054] The gas phase first refrigerant circulating in the first branch z1 and the gas phase second refrigerant circulating in the second branch z2 exchange heat at the heat exchanger 30. At that time, the gas phase second refrigerant with a lower temperature cools the gas phase first refrigerant with a higher temperature, causing it to liquefy and eventually flow to the first expansion valve 14. Therefore, the refrigerant entering the first expansion valve 14 is almost entirely in liquid phase, which helps to reduce the dryness of the first refrigerant after expansion throttling, ensuring that the refrigerant entering the evaporative condenser 15 is mainly in liquid phase, and the first refrigerant can provide a higher cooling capacity at the evaporative condenser 15, so that the second refrigerant can be more fully liquefied and cooled at the evaporative condenser 15, and then the second refrigerant can provide more cooling capacity to the load at the load evaporator 24, greatly improving the COP of the refrigeration system 100.

[0055] In addition, after the second refrigerant in the second branch z2 absorbs the heat of the first refrigerant in the first branch z1, its temperature will increase. The second refrigerant flowing out of the load evaporator 24 is mixed with it, further increasing the superheat. This process helps to increase the return air temperature of the secondary compressor 21, thereby reducing the risk of the secondary compressor 21 being subjected to liquid hammer.

[0056] In some embodiments, reference Figure 1 The refrigeration system 100 includes a control valve f for controlling the flow rate of the flow path, and the control valve f is arranged on the first branch z1 and / or the second branch z2.

[0057] There are many types of control valves f, including solenoid valves, electric valves, etc. The control valve f can be a type that can adjust its own opening, or a type that has only two states: fully open and fully closed.

[0058] A control valve f is provided on the first branch z1 and / or the second branch z2, and the control valve f can be used to control whether the first refrigerant and the second refrigerant perform heat exchange in the heat exchanger 30. When the load has a large cooling demand, the control valve f can be used to conduct the first branch z1 and the second branch z2, and the first refrigerant and the second refrigerant can perform heat exchange in the heat exchanger 30, so that the refrigeration system 100 provides a large cooling capacity. When the load has a small cooling demand, the control valve f can be used to cut off the first branch z1 and / or the second branch z2, so that the refrigeration system 100 provides a small cooling capacity.

[0059] Obviously, there are many options for the configuration position and number of the control valve f on the first branch z1 and the second branch z2. Specifically, on the first branch z1, a control valve f can be provided on either the inlet side or the outlet side of the heat exchanger 30. On the second branch z2, a control valve f can be provided on either the inlet side or the outlet side of the heat exchanger 30.

[0060] It should be noted that the inlet side and the outlet side of the heat exchanger 30 are defined according to the flow direction of the refrigerant on the corresponding branch. Specifically, the side where the refrigerant flows in is called the inlet side, and the side where the refrigerant flows out is called the outlet side.

[0061] In a specific embodiment, referring to Figure 1 The control valve f includes a first valve f1, a second valve f2 and a third valve f3, wherein the first valve f1 is arranged in the first branch z1 and located at the inlet side of the heat exchanger 30, the second valve f2 is arranged in the second branch z2 and located at the inlet side of the heat exchanger 30, and the third valve f3 is arranged in the second branch z2 and located at the outlet side of the heat exchanger 30. The refrigeration system 100 further includes a one-way valve s arranged in the first branch z1 and located at the outlet side of the heat exchanger 30.

[0062] Obviously, the function of the one-way valve s is to only allow the first refrigerant to flow from the heat exchanger 30 to the first expansion valve 14. By setting the first valve f1, the second valve f2, the third valve f3 and the one-way valve s, when the refrigeration system 100 is in low-load operation, the first refrigerant in the primary circulation loop L1 can be restricted to flow only to the first branch z1, and the second refrigerant in the secondary circulation loop L2 can be restricted to flow only to the second branch z2. Such a design helps to reduce the loss of the refrigerant and improve its utilization.

[0063] Figure 2 Schematic diagrams of the components of the refrigeration system 100 according to other embodiments.

[0064] In some embodiments, reference Figure 2 The refrigeration system 100 includes a throttling bypass z3 and a third expansion valve 40. The throttling bypass z3 is arranged in parallel with the secondary circulation loop L2 and is connected between the exhaust end of the secondary compressor 21 and the inlet end of the load evaporator 24. The third expansion valve 40 is arranged in the throttling bypass z3.

[0065] When the refrigeration system 100 is in operation, once the third expansion valve 40 is opened and the throttling bypass z3 is connected, the high-temperature gas phase second refrigerant discharged from the secondary compressor 21 will flow in two ways. One of the ways follows the secondary circulation loop L2, passes through the evaporative condenser 15, the second expansion valve 22 and the second gas-liquid separator 23 in sequence, and forms a low-temperature gas-liquid mixed phase second refrigerant. Subsequently, this part of the second refrigerant is mixed with the other part of the high-temperature gas phase second refrigerant formed after flowing through the third expansion valve 40 along the throttling bypass z3. Then, the mixed second refrigerant flows to the load evaporator 24 and finally returns to the secondary compressor 21.

[0066] Since the mixture of the two second refrigerants circulates in the load evaporator 24, the second refrigerant entering the load evaporator 24 is in a gas-liquid two-phase state, wherein the liquid phase refrigerant is less. Compared with the case where the second refrigerant flows through the load evaporator 24 completely in a liquid phase, when the third expansion valve 40 conducts the throttling bypass z3, the liquid phase component of the second refrigerant entering the load evaporator 24 can be reduced, thereby reducing the cooling capacity provided by the second refrigerant at the load evaporator 24, resulting in a reduction in the cooling capacity of the load evaporator 24. This configuration is suitable for refrigeration scenarios with smaller refrigeration requirements.

[0067] In this way, by controlling the opening degree of the third expansion valve 40 , the refrigeration system 100 can automatically adjust the refrigeration capacity of the load evaporator 24 to meet the refrigeration demand of the small load.

[0068] In actual operation, the refrigeration system 100 can dynamically adjust the temperature of the refrigerant entering the load evaporator 24 by adjusting the opening of the third expansion valve 40 to obtain the second refrigerant of the required temperature.

[0069] It is worth noting that the purpose of opening the third expansion valve 40 to conduct the throttling bypass z3 is to reduce the refrigeration capacity of the load evaporator 24. In contrast, the purpose of opening the first and second branches z2 is to enhance the refrigeration capacity of the load evaporator 24. Therefore, in actual operation, in order to quickly adjust the refrigeration capacity of the load evaporator 24, when the third expansion valve 40 is opened, the first and / or second branches z2 are usually cut off. Conversely, when the first and second branches z2 are conducted, the third expansion valve 40 is usually closed.

[0070] In one embodiment, referring to Figure 2 The refrigeration system 100 includes a first temperature sensor 50 , which is disposed in the secondary circulation loop L2 and located between the outlet of the throttling bypass z3 and the inlet end of the load evaporator 24 .

[0071] The first temperature sensor 50 is used to detect the temperature of the refrigerant entering the load evaporator 24. In the embodiment of the present application, this temperature is referred to as the outlet temperature. The higher the outlet temperature, the lower the cooling capacity provided by the second refrigerant after entering the load evaporator 24. Conversely, the lower the outlet temperature, the higher the cooling capacity provided by the second refrigerant after entering the load evaporator 24.

[0072] In actual application, the openings of the third expansion valve 40, the second expansion valve 22 and the control valve f can be adjusted according to the outlet liquid temperature, thereby controlling the load evaporator 24 to achieve the required refrigeration capacity.

[0073] It is worth noting that, in addition to the main components, the refrigeration system 100 may also include an oil separator 25, a first dryer 16, and a second dryer 26. The oil separator 25 is arranged in the secondary circulation loop L2 and is connected to the exhaust end of the secondary compressor 21. It is necessary to ensure that the inlet end of the throttling bypass z3 is located downstream of the oil separator 25. The first dryer 16 is placed in the primary circulation loop L1, between the first expansion valve 14 and the first gas-liquid separator 13, and its function is to ensure that the refrigerant entering the first expansion valve 14 reaches a dry state. Similarly, the second dryer 26 is located in the secondary circulation loop L2, between the evaporative condenser 15 and the second expansion valve 22, and is responsible for drying the refrigerant entering the second expansion valve 22.

[0074] In addition, the refrigeration system 100 may also install pressure sensors and temperature sensors at the exhaust and return ends of the primary compressor 11 and the secondary compressor 21 to monitor their exhaust pressure, exhaust temperature, return pressure and return temperature to ensure their normal operation.

[0075] In a specific embodiment, the refrigeration system 100 includes a primary refrigeration module 10, a secondary refrigeration module 20, a first branch z1, a second branch z2, a heat exchanger 30, a throttling bypass z3, a third expansion valve 40 and a first temperature sensor 50. The first valve f1 and the one-way valve s are arranged on the first branch z1, and the second valve f2 and the third valve f3 are arranged on the second branch z2.

[0076] The refrigeration system 100 has multiple operating modes.

[0077] Specifically, the refrigeration system 100 has a standard refrigeration mode, in which the components of the primary refrigeration module 10 and the secondary refrigeration module 20 work normally, and the first valve f1, the second valve f2, the third valve f3, and the third expansion valve 40 are all closed. At this time, only the primary circulation loop L1 is connected to the secondary circulation loop L2, the first branch z1, the second branch z2, and the throttling bypass z3 are all cut off, and the refrigeration system 100 is suitable for occasions with general refrigeration demand.

[0078] In addition, the refrigeration system 100 also has a large refrigeration working mode. In this mode, based on the standard refrigeration mode, the first valve f1, the second valve f2 and the third valve f3 are switched to the open state, and the first branch z1 and the second branch z2 are connected. At this time, the refrigerant refrigeration loss of the refrigeration system 100 is low, and a large refrigeration capacity can be provided at the load evaporator 24. The COP of the refrigeration system 100 is high, which is very suitable for those occasions with large refrigeration requirements.

[0079] In addition, the refrigeration system 100 also has a small refrigeration working mode, in which, based on the standard refrigeration mode, the third expansion valve 40 is switched to an open state, and the throttling bypass z3 is connected. At this time, the refrigerant of the refrigeration system 100 provides a small refrigeration capacity at the load evaporator 24, which is suitable for occasions with a small refrigeration demand.

[0080] Therefore, the refrigeration system 100 can select a corresponding operating mode according to actual load refrigeration requirements, thereby achieving more flexible application.

[0081] Based on the refrigeration system 100 proposed in the above embodiments, the embodiments of the present application further provide a control method of the refrigeration system 100 that can be applied to some of the above embodiments. Figure 3 FIG. 3 is a flow chart of a control method of a refrigeration system 100 in some embodiments. Referring to FIG. 3 , the control method includes:

[0082] S10, obtaining refrigeration demand parameters, and determining the working mode of the refrigeration system 100 according to the refrigeration demand parameters;

[0083] Specifically, the refrigeration system 100 can be equipped with a controller, or a controller can be configured on a test device equipped with the refrigeration system 100. This controller is connected to each electrical component in the refrigeration system 100 and is responsible for controlling their operation. Generally, the controller includes a processor and a memory, and the processor can be a central processing unit, a microprocessor, an embedded single-chip microcomputer, etc. The memory is connected to the processor for storing corresponding programs. When the processor executes these programs, each step of the control method described in the embodiment of the present application can be implemented.

[0084] The refrigeration demand parameter is used to characterize the refrigeration capacity that the refrigeration system 100 needs to provide. For example, the refrigeration demand parameter can be an operating mode instruction. For example, if the refrigeration demand parameter is a first mode instruction, when the refrigeration demand parameter is obtained, it can be determined that the operating mode of the refrigeration system 100 is a large refrigeration operating mode corresponding to the first mode instruction. When using the refrigeration system 100, the staff can trigger the operating mode instruction by selecting the operating mode (selection methods include touch screen, keyboard, button, etc.).

[0085] S20, when it is determined that the working mode of the refrigeration system 100 is the large refrigeration working mode, the primary refrigeration module 10 and the secondary refrigeration module 20 are enabled, and the first branch z1 and the second branch z2 are turned on.

[0086] When the primary refrigeration module 10 and the secondary refrigeration module 20 are enabled, the primary compressor 11 and the secondary compressor 21 are controlled to start, and the first expansion valve 14 and the second expansion valve 22 are opened. At this time, the first refrigerant circulates in the primary circulation loop L1, and the second refrigerant circulates in the secondary circulation loop L2.

[0087] The refrigeration system 100 includes a control valve f, and the control valve f is configured on the first branch z1 and / or the second branch z2. Specifically, the first branch z1 and the second branch z2 are connected by opening the control valve f. For example, when the control valve f includes the first valve f1, the second valve f2, and the third valve f3 mentioned in the above embodiment, in step S20, the first branch z1 and the second branch z2 can be connected by controlling the first valve f1, the second valve f2, and the third valve f3 to be opened.

[0088] In the large refrigeration working mode, the flow condition of the refrigerant in the refrigeration system 100 is as follows: the high-temperature gas phase first refrigerant discharged from the first-stage compressor 11, after being cooled by the condenser 12, flows into the first gas-liquid separator 13 for gas-liquid two-phase separation. The separated gas phase first refrigerant flows into the first branch z1. At the same time, the high-temperature gas phase second refrigerant discharged from the second-stage compressor 21, after being cooled at the evaporative condenser 15, flows into the second expansion valve 22, and then the gas-liquid two-phase separation is carried out in the second gas-liquid separator 23. The separated gas phase second refrigerant enters the second branch z2, and the gas phase first refrigerant circulating on the first branch z1 is cooled in the heat exchanger 30, so as to promote the liquefaction of the gas phase first refrigerant.

[0089] The liquefied first refrigerant flows out from the first branch z1 and flows back to the primary circulation loop L1, mixes with the liquid phase first refrigerant separated from the first gas-liquid separator 13, and after throttling through the first expansion valve 14, cools the refrigerant on the secondary circulation loop L2 at the evaporative condenser 15. At the same time, the liquid phase second refrigerant separated from the second gas-liquid separator 23 enters the load evaporator 24 to cool the load.

[0090] At this time, the refrigerant entering the first expansion valve 14 is almost completely in liquid phase, which helps to reduce the dryness of the first refrigerant after passing through the expansion throttling, ensuring that the refrigerant entering the evaporative condenser 15 is mainly in liquid phase. The first refrigerant can provide a higher cooling capacity at the evaporative condenser 15, so that the second refrigerant can be more fully liquefied and cooled at the evaporative condenser 15, and then the second refrigerant can provide more cooling capacity to the load at the load evaporator 24, greatly improving the COP of the refrigeration system 100.

[0091] Moreover, after the second refrigerant in the second branch z2 absorbs the heat of the first refrigerant in the first branch z1, its temperature will increase. The second refrigerant flowing out of the load evaporator 24 is mixed with it, further increasing the superheat. This process helps to increase the return air temperature of the secondary compressor 21, thereby reducing the risk of the secondary compressor 21 being subjected to liquid hammer.

[0092] Figure 4 Schematic diagram of a flow chart of a control method of the refrigeration system 100 in some other embodiments.

[0093] In some embodiments, reference Figure 4 , after step S20 of determining the working mode of the refrigeration system 100 according to the refrigeration demand parameter, the method further includes:

[0094] S30, when it is determined that the working mode of the refrigeration system 100 is the small refrigeration working mode, the primary refrigeration module 10 and the secondary refrigeration module 20 are enabled, the first branch z1 and the second branch z2 are cut off, and the throttling bypass z3 is turned on.

[0095] Correspondingly, step S20 also includes: closing the throttling bypass z3.

[0096] In this embodiment, the refrigeration system 100 further includes the throttling bypass z3 and the third expansion valve 40. For the configuration of the two, please refer to the above description and will not be repeated here.

[0097] Specifically, when it is determined that the refrigeration system 100 enters the small refrigeration working mode, the control valve f is closed so that the first branch z1 or the second branch z2 is cut off, and the heat exchange of the gas phase refrigerant cannot be performed in the heat exchanger 30. In addition, after the third expansion valve 40 is opened, the high-temperature gas phase refrigerant discharged from the secondary compressor 21 is diverted through the throttling bypass z3, so that the temperature of the refrigerant entering the load evaporator 24 is increased, and its refrigeration capacity is reduced, thereby meeting the small refrigeration capacity demand.

[0098] When the control valve f includes the first valve f1, the second valve f2 and the third valve f3, in the step S30, the first valve f1, the second valve f2 and the third valve f3 are controlled to be closed at the same time.

[0099] Obviously, in the case where the refrigeration system 100 is equipped with the throttling bypass z3 and the third expansion valve 40, when the working mode of the refrigeration system 100 is determined to be the large refrigeration working mode, when the primary refrigeration module 10 and the secondary refrigeration module 20 are enabled and the first branch z1 and the second branch z2 are connected, the third expansion valve 40 needs to be closed to cut off the throttling bypass z3, so that the refrigeration system 100 can provide a large refrigeration capacity. Of course, other valves can also be set on the throttling bypass z3 to achieve the purpose of controlling its on and off.

[0100] In this way, the refrigeration system 100 can switch the working mode according to the load size requirements, so that the refrigeration capacity it provides matches the load size, which is not only more energy-saving but also more flexible.

[0101] Specifically in the embodiment, the refrigeration demand parameter includes at least one of the target liquid outlet temperature Tc, the target load temperature Tf, the equipment operation state parameter and the actual load temperature Ts;

[0102] In step S10, the working mode of the refrigeration system 100 is determined according to the refrigeration demand parameter, including:

[0103] S11. When t3≤Tc≤t2<0, or Tf>t1>0 and the equipment operation status parameters are high temperature test condition parameters, or Ts>t1 and Tf<t2 are satisfied, it is determined that the working mode of the refrigeration system 100 is the large refrigeration working mode; wherein t1, t2 and t3 are all preset temperatures.

[0104] As mentioned above, the liquid outlet temperature refers to the temperature of the second refrigerant when it enters the load evaporator 24. Specifically, this temperature is detected by the first temperature sensor 50 located in the secondary circulation loop L2. For the setting method of the first temperature sensor 50, please refer to the above description. Accordingly, the target liquid outlet temperature Tc refers to the expected liquid outlet temperature set by the operator for the system.

[0105] The target load temperature Tf may be understood as the production temperature that the test equipment equipped with the refrigeration system 100 is expected to reach. Correspondingly, the actual load temperature Ts may be understood as the production temperature that the test equipment equipped with the refrigeration system 100 actually reaches.

[0106] It should be clear that the test equipment may include heating elements in addition to the refrigeration system 100. These heating elements work together with the refrigeration system 100 to adjust the temperature so as to provide accurate temperature control to the test terminal of the test equipment (used to provide the required test environment for the test piece). The production temperature refers to the test temperature required by the test terminal. The specific structure of the test equipment and the test terminal will be described in detail in the subsequent content.

[0107] The equipment operation state parameters refer to the operation state parameters of the test equipment equipped with the refrigeration system 100. For the test equipment, its operation state covers three states: heat confrontation, cold confrontation and cold and hot balance. When in the heat confrontation state, the actual production temperature provided by the test equipment exceeds the target production temperature, indicating that the heating component is overheated. In this case, it is necessary to enhance the cooling capacity of the refrigeration system 100 to offset the excess heat generated by the heating component. On the contrary, if the test equipment is in the cold confrontation state, it means that the actual production temperature provided by the test equipment is lower than the target production temperature, indicating that the cooling amount provided by the refrigeration system 100 is too much. At this time, the cooling capacity of the refrigeration system 100 should be reduced or the working power of the heating component should be increased. When the test equipment reaches the cold and hot balance state, the cooling capacity generated by the refrigeration system 100 matches the heat generated by the heating component, and the actual production temperature provided by the test equipment is consistent with or close to the target temperature.

[0108] Specifically, a temperature sensor can be installed at the test terminal to monitor the actual load temperature Ts. The processing device (whether a controller or other processing unit) determines the operating state of the test device by comparing the difference between the actual load temperature Ts and the target load temperature Tc, and obtains the operating state parameters of the test device.

[0109] In addition, test equipment usually covers a variety of test conditions, including high temperature and low temperature testing. In high temperature test conditions, the test equipment can provide a higher temperature environment (generally higher than room temperature) for the device under test. In low temperature test conditions, the test equipment can provide a temperature environment below 0°C for the device under test. Usually, the thermal confrontation state occurs in high temperature test conditions.

[0110] It is worth noting that t3<t2<0<t1. t1 is usually but not limited to being set to normal temperature, such as 25°C. As an example, t2 can be but not limited to being preset to -20°C, and t3 can be but not limited to being preset to -70°C.

[0111] Specifically, the refrigeration demand parameter may only include the target liquid outlet temperature Tc, and the working mode may be determined by comparing Tc with the preset temperatures t2 and t3. When t3≤Tc≤t2<0 is satisfied, it means that the temperature of the refrigerant entering the load evaporator 24 is relatively low, and the refrigeration system 100 needs to provide a larger refrigeration capacity, and the working mode of the refrigeration system 100 is determined to be a large refrigeration working mode to provide a larger refrigeration capacity.

[0112] In addition, the refrigeration demand parameter may also only include the target load temperature Tf and the equipment operating status parameter. When Tf>t1>0 is satisfied and the equipment operating status parameter indicates that the test equipment is in a thermal confrontation state, the test equipment is in a high temperature test condition, and the power of the heating element is increased, and more heat is generated, resulting in a higher production temperature. At this time, the refrigeration capacity of the refrigeration system 100 can be increased to reduce the production temperature to a suitable value, and the working mode of the refrigeration system 100 is determined to be a large refrigeration working mode to provide a larger refrigeration capacity.

[0113] In addition, the cooling demand parameters may also only include the actual load temperature Ts and the target load temperature Tf, and when Ts>t1 and Tf<t2, it means that the load cooling demand is large, and the refrigeration system 100 needs to provide a large cooling capacity to reduce the load from high temperature to below 0°C, then it is determined that the working mode of the refrigeration system 100 is a large cooling working mode to provide a large cooling capacity.

[0114] Of course, in other embodiments, those skilled in the art can flexibly combine these characteristic parameters (including the target liquid outlet temperature Tc, the target load temperature Tf, the equipment operating status parameters and the actual load temperature Ts), and thereby design other judgment methods for identifying the working mode of the refrigeration system 100.

[0115] If the refrigeration system 100 determines its working mode according to the outlet liquid temperature, the structure and control can be simplified. If the refrigeration system 100 determines its working mode according to the actual load temperature Ts and the target load temperature Tf, it is closer to the load demand and the refrigeration result is more reliable. If the refrigeration system 100 determines its working mode according to the target load temperature Tf and the equipment operating status parameters, the refrigeration capacity of the refrigeration system 100 can be increased under thermal resistance conditions, making the actual production temperature of the test equipment more accurate.

[0116] In some embodiments, the refrigeration demand parameter includes a target liquid outlet temperature Tc. In step S10, the operating mode of the refrigeration system 100 is determined according to the refrigeration demand parameter, including:

[0117] S12. When t4≤Tc≤0 is satisfied, it is determined that the working mode of the refrigeration system 100 is a low-refrigeration working mode, wherein t4 is a preset temperature and is greater than t2.

[0118] t4 is a preset value, for example, -10° C. When t4≤Tc≤0 is satisfied, it means that the load only requires the refrigeration system 100 to provide a small amount of refrigeration. In this way, it can be determined that the working mode of the refrigeration system 100 is a small refrigeration working mode.

[0119] At this time, judging whether the refrigeration system 100 enters the low-refrigeration working mode is performed according to the configuration value of the target liquid outlet temperature Tc, so that the structure of the refrigeration system 100 can be simplified and the control can be simplified.

[0120] It is worth adding that in the small refrigeration working mode, the third expansion valve 40, and even the opening of the second expansion valve 22, the first valve f1, the second valve f2 and the third valve f3 can be adjusted according to the difference between the target liquid outlet temperature Tc and the actual liquid outlet temperature (collected by the first temperature sensor 50), so that the actual liquid outlet temperature is close to or even reaches the target liquid outlet temperature Tc.

[0121] Of course, in other embodiments, the determination of the small cooling working mode can also be determined based on other parameters in the cooling demand parameters. For example, if the operating state parameters of the test device indicate that it is in a cold resistance state, it can be determined that the refrigeration system enters the small cooling working mode to reduce the cooling capacity of the refrigeration system. For another example, if the difference between the target load temperature Tc and the actual load temperature Ts of the test device is less than the set value, indicating that the load cooling demand is small, it can be determined that the refrigeration system enters the small cooling working mode to provide a small cooling capacity to the load.

[0122] In addition, the refrigeration system 100 may have a standard refrigeration mode in addition to the large refrigeration working mode and the small refrigeration working mode. In the standard refrigeration mode, the refrigeration capacity provided by the refrigeration system 100 is between the small refrigeration working mode and the large refrigeration working mode to match the load demand of general refrigeration demand. As a result, the refrigeration system 100 has more diverse working modes and can adapt to a variety of loads with different refrigeration demands, and the refrigeration system 100 is more comprehensive and widely used.

[0123] In some embodiments, determining the working mode of the refrigeration system 100 according to the refrigeration demand parameter further includes:

[0124] S40, when it is determined that the working mode of the refrigeration system 100 is the standard working mode, the primary refrigeration module 10 and the secondary refrigeration module 20 are enabled, and the first branch z1, the second branch z2 and the throttling bypass z3 are cut off.

[0125] Specifically, when the refrigeration demand parameters include the target liquid outlet temperature Tc, if t2<Tc<t4 is satisfied, that is, the refrigeration capacity demand is neither too large nor too small, then only the first-level refrigeration module 10 and the second-level refrigeration module 20 can be enabled. There is no need to enable the first branch z1 and the second branch z2 to increase the cooling capacity, nor is there any need to enable the throttling bypass z3 to reduce the cooling capacity. At this time, the refrigeration system 100 is suitable for scenarios with general refrigeration demands.

[0126] The test device provided in the embodiment of the present application includes a test terminal, a heating element and a refrigeration system 100. The refrigeration system 100 and the heating element are used together to adjust the test temperature of the test terminal. The refrigeration system 100 is the refrigeration system 100 described in any of the above embodiments, or the refrigeration system 100 can execute the control method described in any of the above embodiments. The test device has all the beneficial effects described above.

[0127] Specifically, the test equipment can be a sorting and testing equipment or a probe station equipment for testing semiconductor devices such as chips or wafers. The test terminals can be test heads, test chambers, preheating plates, shuttles, wafer carrier plates, etc. The test chamber is a cavity structure for providing a test space, and multiple chips or wafers can be stored in the test space. The load evaporator 24 of the refrigeration system 100 can be arranged in the test space to adjust the test temperature of the test space. The test head refers to a head structure that can press down and abut against the chip, and it directly contacts the chip to control the temperature of the chip. The load evaporator 24 of the refrigeration system 100 can be used for cooling the coolant, and then the coolant-carrying pipeline where the coolant is located is connected to the pipeline inside the test head to adjust the temperature of the test head. The preheating plate refers to a structure for carrying the chip and adjusting the temperature of the chip, and the coolant-carrying pipeline can be connected to the pipeline of the preheating plate to adjust the temperature of the preheating plate. The shuttle refers to a structure for transporting the chip, and the coolant-carrying pipeline can be connected to the pipeline inside the shuttle to adjust the temperature of the shuttle. The wafer carrier plate refers to a plate that carries the wafer by adsorption, and the coolant-carrying pipeline can be connected to the pipeline inside the wafer carrier plate to adjust the test temperature of the wafer.

[0128] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0129] The above-described embodiments only represent several implementation manners of the present application. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the patent of the present application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1. A refrigeration system, characterized in that: include: A primary refrigeration module (10) comprises a primary compressor (11), a condenser (12), a first gas-liquid separator (13), a first expansion valve (14) and an evaporative condenser (15) which are sequentially arranged on a primary circulation loop (L1); A secondary refrigeration module (20) comprises a secondary compressor (21), a second expansion valve (22), a second gas-liquid separator (23) and a load evaporator (24) which are sequentially arranged on a secondary circulation loop (L2); the secondary refrigeration module (20) and the primary refrigeration module (10) share the evaporative condenser (15), and the evaporative condenser (15) is located between the secondary compressor (21) and the second gas-liquid separator (23) on the secondary circulation loop (L2); The refrigeration system further comprises a first branch (z1), a second branch (z2) and a heat exchanger (30), wherein the first branch (z1) is connected to the gas outlet of the first gas-liquid separator (13) and the inlet of the first expansion valve (14), and the second branch (z2) is connected to the gas outlet of the second gas-liquid separator (23) and the return gas end of the secondary compressor (21), and the first branch (z1) and the second branch (z2) both pass through the heat exchanger (30) and exchange heat via the heat exchanger (30).

2. The refrigeration system according to claim 1, characterized in that: The refrigeration system comprises a control valve (f) for controlling the flow rate of the flow path, and the control valve (f) is arranged on the first branch (z1) and / or the second branch (z2).

3. The refrigeration system according to claim 2, characterized in that: The control valve (f) comprises a first valve (f1), a second valve (f2) and a third valve (f3); The first valve (f1) is arranged on the first branch (z1) and is located at the inlet side of the heat exchanger (30), the second valve (f2) is arranged on the second branch (z2) and is located at the inlet side of the heat exchanger (30), and the third valve (f3) is arranged on the second branch (z2) and is located at the outlet side of the heat exchanger (30); The refrigeration system further comprises a one-way valve (s) arranged in the first branch (z1) and located at the outlet side of the heat exchanger (30).

4. The refrigeration system according to any one of claims 1 to 3, characterized in that: The refrigeration system comprises a throttling bypass (z3) and a third expansion valve (40); The throttling bypass (z3) is arranged in parallel with the secondary circulation loop (L2) and is connected between the exhaust end of the secondary compressor (21) and the inlet end of the load evaporator (24). The third expansion valve (40) is arranged in the throttling bypass (z3).

5. The refrigeration system according to claim 4, characterized in that: The refrigeration system comprises a first temperature sensor (50), which is arranged in the secondary circulation loop (L2) and located between the outlet of the throttling bypass (z3) and the inlet end of the load evaporator (24).

6. A control method for a refrigeration system, applied to the refrigeration system according to any one of claims 2 to 5, characterized in that: The control method comprises: Acquiring a refrigeration demand parameter, and determining an operating mode of the refrigeration system according to the refrigeration demand parameter; When it is determined that the working mode of the refrigeration system is a large refrigeration working mode, the primary refrigeration module (10) and the secondary refrigeration module (20) are enabled, and the first branch (z1) and the second branch (z2) are connected.

7. The control method according to claim 6, characterized in that: After determining the working mode of the refrigeration system according to the refrigeration demand parameter, the method further includes: When it is determined that the working mode of the refrigeration system is a small refrigeration working mode, the primary refrigeration module (10) and the secondary refrigeration module (20) are enabled, the first branch (z1) and the second branch (z2) are cut off, and the throttling bypass (z3) is turned on; Accordingly, when it is determined that the working mode of the refrigeration system is the large refrigeration working mode, the method further includes: shutting off the throttling bypass (z3); The throttling bypass (z3) is arranged in parallel with the secondary circulation loop (L2), and is connected between the exhaust end of the secondary compressor (21) and the inlet end of the load evaporator (24), and the third expansion valve (40) is arranged in the throttling bypass (z3).

8. The control method according to claim 7, characterized in that: The refrigeration demand parameter includes at least one of a target liquid outlet temperature Tc, a target load temperature Tf, an equipment operation status parameter, and an actual load temperature Ts; The determining the working mode of the refrigeration system according to the refrigeration demand parameter comprises: When t3≤Tc≤t2<0, or Tf>t1>0 and the equipment operation state parameter is a thermal resistance parameter, or Ts>t1 and Tf<t2 are satisfied, it is determined that the working mode of the refrigeration system is a large refrigeration working mode; Among them, t1, t2 and t3 are all preset temperatures.

9. The control method according to claim 8, characterized in that: The refrigeration demand parameter includes the target liquid outlet temperature Tc; The determining the working mode of the refrigeration system according to the refrigeration demand parameter comprises: When t4≤Tc≤0 is satisfied, it is determined that the working mode of the refrigeration system is a small refrigeration working mode, wherein t4 is a preset temperature and is greater than t2.

10. A testing device, characterized in that: It includes a test terminal, a heating element and a refrigeration system, wherein the refrigeration system and the heating element are used together to adjust the test temperature of the test terminal, and the refrigeration system is the refrigeration system as described in any one of claims 1 to 5, or the refrigeration system can execute the control method as described in any one of claims 6 to 9.

Images