Control method of refrigeration system, refrigeration system and test equipment

Abstract

The invention relates to a control method of a refrigerating system, the refrigerating system and test equipment. The control method comprises the steps that the current superheat degree and the superheat degree lower limit value of a compressor are obtained; according to the current superheat degree and the superheat degree lower limit value, whether the refrigerating system meets the superheat degree adjusting condition or not is determined, and the superheat degree adjusting condition is used for representing that return air of a compressor carries liquid; and if the refrigerating system meets the superheat degree adjusting condition, a regulation and control mode is entered, and the regulation and control mode comprises a main throttling element regulation and control mode and a regulating valve regulation and control mode. According to the technical scheme, when it is judged that the return air of the compressor carries liquid, the content of the liquid refrigerant entering the compressor is reduced by adjusting the opening degree of the main throttling piece on the circulation loop and adjusting the opening degree of the adjusting valve on the cooling flow path, the effect of improving the return air of the compressor carries liquid is obvious, and the service life of the compressor is prolonged. The risk that the compressor is damaged due to liquid impact can be reduced, and the service life of the compressor is prolonged.

Description

Technical Field

[0001] The present application relates to the field of refrigeration technology, and in particular to a control method for a refrigeration system, a refrigeration system and a testing device. Background Art

[0002] Chip testing is an important part of the chip manufacturing process, which aims to reduce the potential failure rate of the chip in the early stage. Chip testing equipment is usually equipped with a refrigeration system to create a test temperature environment for it. The test temperature of chip testing equipment is usually set in the range of -55℃ to 150℃. When the heat load decreases, the liquid refrigerant in the refrigeration system cannot be fully evaporated, and it is easy for the return air to carry liquid, resulting in a large amount of liquid refrigerant entering the compressor to participate in compression. Long-term operation will cause damage to the compressor and reduce the service life of the compressor.

[0003] In order to avoid liquid in the return air from the compressor, the industry often adds a gas-liquid separator to the refrigeration system. When the gas-liquid two-phase refrigerant returns through the gas-liquid separator, the gas-liquid separator separates the gaseous refrigerant from the liquid refrigerant and lubricating oil in the return air. The liquid refrigerant and lubricating oil are deposited at the bottom, and the lubricating oil flows back to the compressor through the oil return port of the gas-liquid separator. When the system continues to carry liquid, the liquid refrigerant easily fills the gas-liquid separator, causing the gas-liquid separator to fail. Moreover, when the refrigerant density is greater than the lubricating oil, the lubricating oil will still bring in liquid refrigerant when returning from the gas-liquid separator to the compressor. Summary of the invention

[0004] Based on this, it is necessary to provide a control method, a refrigeration system and a testing device for a refrigeration system to address the problem of reducing the service life of the compressor due to liquid refrigerant entering the compressor.

[0005] In a first aspect, the present application provides a control method for a refrigeration system, wherein the refrigeration system comprises a compressor, a condenser, a main throttling device and an evaporator which are sequentially connected to form a circulation loop, wherein the condenser comprises a cooling flow path for circulating an external coolant, and a regulating valve is arranged on the cooling flow path;

[0006] The control method comprises:

[0007] Get the current superheat and superheat lower limit of the compressor;

[0008] Determining whether the refrigeration system meets a superheat adjustment condition according to the current superheat and the superheat lower limit, wherein the superheat adjustment condition is used to characterize liquid in the compressor return gas;

[0009] If the refrigeration system meets the superheat adjustment condition, it enters the control mode, and the control mode includes the main throttle control mode and the regulating valve control mode;

[0010] Wherein, in the main throttling element control mode, the opening of the main throttling element is lowered; in the regulating valve control mode, the opening of the regulating valve is lowered.

[0011] In some embodiments, if the refrigeration system meets the superheat adjustment condition, entering the control mode includes:

[0012] If the refrigeration system meets the superheat adjustment condition, the main throttling device adjustment mode is entered, and it is determined whether the refrigeration system reaches a first critical condition, wherein the first critical condition is used to indicate that the main throttling device is in a critical state that can be safely adjusted;

[0013] If the refrigeration system does not reach the first critical condition and does not meet the superheat adjustment condition, then exit the main throttling device control mode;

[0014] If the refrigeration system reaches the first critical condition and satisfies the superheat adjustment condition, the main throttling element adjustment mode is exited and the adjustment valve adjustment mode is entered.

[0015] In some embodiments, lowering the opening of the main throttle member includes:

[0016] Acquire pressure interval information, wherein the pressure interval information is obtained by equally dividing the pressure range formed by the maximum return air pressure and the minimum return air pressure of the compressor, and includes a plurality of pressure intervals sorted in order according to the size of the interval values;

[0017] Acquire the current return air pressure of the compressor, and determine, from the pressure interval information according to the current return air pressure, the pressure interval where the current return air pressure is located as the control interval;

[0018] Determine a target interval according to the control interval and the pressure interval information; the target interval is the pressure interval whose interval value is smaller than the control interval and whose arrangement order is adjacent to the control interval;

[0019] Determine a target pressure value according to the target interval, the target pressure value belongs to the target interval; determine a first opening degree reduction according to the target pressure value and a first preset calculation rule;

[0020] The current opening of the main throttle member is adjusted downward according to the first opening reduction.

[0021] In some embodiments, before determining the target interval according to the control interval and the pressure interval information, the method further includes:

[0022] Determine whether the control interval is a lower limit interval; the lower limit interval is the pressure interval with the smallest interval value;

[0023] If yes, it is determined that the refrigeration system has reached a first critical condition, and the main throttling device control mode is exited;

[0024] If not, executing: determining a target interval according to the control interval and the pressure interval information.

[0025] In some embodiments, after reducing the current opening of the main throttle member according to the first opening reduction, the method further includes:

[0026] Controlling the first working duration of the main throttling member according to the current opening of the main throttling member after adjustment;

[0027] If the refrigeration system meets the superheat adjustment condition, the execution returns to: obtaining the current return air pressure of the compressor, and determining the pressure interval where the current return air pressure is located as the control interval from the pressure interval information according to the current return air pressure.

[0028] In some embodiments, lowering the opening of the regulating valve includes:

[0029] Obtaining target exhaust superheat;

[0030] Get the current exhaust superheat of the compressor;

[0031] Determining a second opening degree reduction according to a difference between the target exhaust superheat and the current exhaust superheat and based on a second preset calculation rule;

[0032] The current opening degree of the regulating valve is reduced by the second opening degree.

[0033] In some embodiments, after reducing the current opening of the regulating valve by the second opening, the method further includes:

[0034] Controlling the second working time of the regulating valve according to the current opening of the regulating valve after adjustment;

[0035] If the refrigeration system meets the superheat adjustment condition and does not meet the second critical condition, return to execute: obtaining the current exhaust superheat of the compressor;

[0036] Among them, the second critical condition is used to characterize that the regulating valve is in a critical state that can be safely controlled, including at least one of the current opening of the regulating valve being lower than the lower limit of the regulating valve opening, the current exhaust pressure of the compressor being higher than the upper limit of the exhaust pressure, and the current exhaust superheat of the compressor being higher than the upper limit of the exhaust superheat.

[0037] In some embodiments, if the refrigeration system reaches the first critical condition and satisfies the superheat adjustment condition, then the main throttling device control mode is exited and the regulating valve control mode is entered, further comprising:

[0038] If the refrigeration system reaches the second critical condition and satisfies the superheat adjustment condition, exit the regulating valve control mode and enter the refrigerant temperature control mode until the refrigeration system no longer satisfies the superheat adjustment condition; in the refrigerant temperature control mode, control the refrigeration system to increase the return air temperature of the compressor.

[0039] In some embodiments, the circulation loop includes a return air main path located between the outlet side of the evaporator and the compressor, the refrigeration system includes a return air bypass arranged in parallel with the return air main path, a regenerator is arranged on the return air bypass, and the regenerator has a heat recovery flow path for heating the return air bypass; a first control valve is arranged on the return air bypass between the regenerator and the evaporator, and a second control valve is arranged on the return air main path; the heat recovery flow path is composed of the flow path between the compressor and the condenser in the circulation loop, or the heat recovery flow path is composed of the cooling flow path, and the heat recovery flow path is located downstream of the condenser in the flow direction of the coolant in the cooling flow path; controlling the refrigeration system to increase the return air temperature of the compressor includes: opening the first control valve and closing the second control valve.

[0040] In some embodiments, the refrigeration system includes a throttling bypass connected to the inlet side of the condenser and the outlet side of the main throttling device, and a secondary throttling device is arranged on the throttling bypass; controlling the refrigeration system to increase the return air temperature of the compressor includes: opening the secondary throttling device.

[0041] In a second aspect, the present application provides a refrigeration system, comprising a compressor, a condenser, a main throttling device and an evaporator connected in sequence to form a circulation loop, the condenser comprising a cooling flow path for circulating an external coolant, and a regulating valve is arranged on the cooling flow path; the refrigeration system is capable of executing the control method described in any of the above embodiments.

[0042] In a third aspect, the present application provides a testing device, including a testing terminal and a refrigeration system as described in the above embodiment, wherein the refrigeration system is used to adjust the temperature of the testing terminal.

[0043] The control method, refrigeration system and testing equipment of the above-mentioned refrigeration system determine whether the compressor return air carries liquid through the superheat of the compressor. When it is determined that the compressor return air carries liquid, the liquid refrigerant content entering the compressor is reduced by two fine-tuning means, namely, lowering the opening of the main throttling device on the circulation loop and lowering the opening of the regulating valve on the cooling flow path. This has a significant effect on improving the liquid return air of the compressor, helps to reduce the risk of damage to the compressor due to liquid hammer, and extends the service life of the compressor. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] 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:

[0045] Figure 1 A system schematic diagram of a refrigeration system according to some embodiments.

[0046] Figure 2 The figure is a flowchart of a control method of a refrigeration system in some embodiments.

[0047] Figure 3 Schematic diagram of the flow of control methods for refrigeration systems in other embodiments.

[0048] Figure 4 The present invention is a detailed flow chart of the step of lowering the opening degree of the main throttling member in the control method of the refrigeration system in some embodiments.

[0049] Figure 5 A detailed flow chart of lowering the opening of the main throttling member in a control method for a refrigeration system in some other embodiments.

[0050] Figure 6 A detailed flow chart of lowering the opening of the main throttling member in a control method for a refrigeration system in some other embodiments.

[0051] Figure 7 It is a detailed schematic diagram of a flow chart for lowering the opening of a regulating valve in a control method for a refrigeration system in some embodiments.

[0052] Figure 8 It is a detailed schematic diagram of a flow chart of lowering the opening of a regulating valve in a control method of a refrigeration system in some other embodiments.

[0053] Fig. 9 Schematic diagram of the flow of control methods for refrigeration systems in other embodiments.

[0054] Fig.10 Schematic diagram of the composition of refrigeration systems in other embodiments.

[0055] Fig.11 Schematic diagram of the composition of refrigeration systems in other embodiments.

[0056] Fig.12 Schematic diagram of the composition of refrigeration systems in other embodiments.

[0057] The reference numerals in the specific implementation manner are as follows:

[0058] 100, refrigeration system; 10, compressor; 20, condenser; L1, cooling flow path; 21, regulating valve; 30, main throttling device; 40, evaporator; 50, gas-liquid separator; 60, regenerator; L2, heat recovery flow path; 70, secondary throttling device; f1, first control valve; f2, second control valve; S, circulation loop; S1, return air main path; H, return air bypass; J, throttling bypass. DETAILED DESCRIPTION

[0059] 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.

[0060] 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.

[0061] 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.

[0062] 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.

[0063] 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.

[0064] 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.

[0065] In response to the problems mentioned in the background technology, the embodiments of the present application provide a control method for a refrigeration system, a refrigeration system and a testing device.

[0066] To facilitate understanding of the description, the refrigeration system in the embodiment of the present application is first introduced.

[0067] Figure 1 FIG. 1 is a schematic diagram of a refrigeration system 100 according to some embodiments. Figure 1 The refrigeration system 100 in the embodiment of the present application includes a compressor 10, a condenser 20, a main throttling device 30 and an evaporator 40 which are connected in sequence to form a circulation loop S. The condenser 20 includes a cooling flow path L1 for circulating an external coolant, and a regulating valve 21 is provided on the cooling flow path L1.

[0068] When the refrigeration system 100 is cooling, the exhaust end of the compressor 10 discharges high-temperature and high-pressure gaseous refrigerant, and the high-temperature and high-pressure gaseous refrigerant exchanges heat with the coolant flowing in the cooling flow path L1 at the condenser 20 to be cooled, and then flows through the main throttling device 30 to be cooled and throttled to become a low-temperature and low-pressure liquid refrigerant. The low-temperature and low-pressure liquid refrigerant cools the external heat load at the evaporator 40 to form a low-temperature and low-pressure gaseous refrigerant, and finally flows back to the return air end of the compressor 10, and is compressed again to form a high-temperature and high-pressure gaseous refrigerant, and the cycle is repeated.

[0069] The coolant may be cooling water or a refrigerant such as fluorinated liquid. The regulating valve 21 is disposed on the cooling flow path L1 to adjust the flow of the coolant on the cooling flow path L1, thereby adjusting the degree of condensation of the refrigerant by the condenser 20.

[0070] In addition, in other embodiments, the refrigeration system 100 may further include a gas-liquid separator 50, which is arranged on the circulation loop S and connected to the return air end of the compressor 10. Regarding other configuration information of the refrigeration system 100, those skilled in the art can perform conventional designs to improve the operating stability of the refrigeration system 100, such as setting an oil separator on the exhaust side of the compressor 10, etc. Regarding the specific selection of devices such as the compressor 10, the condenser 20, the main throttling device 30, the evaporator 40, etc., please refer to the conventional selection in the field, which is not limited here. It should be noted that the main throttling device 30 in the embodiment of the present application and the secondary throttling device 70 mentioned below can be selected from conventional throttle valves, expansion valves, expansion throttle valves and other conventional components in the refrigeration field.

[0071] Based on the refrigeration system 100 in the above embodiment, the control method of the refrigeration system proposed in the embodiment of the present application is introduced in detail below.

[0072] Figure 2 FIG. 1 is a flow chart of a control method for a refrigeration system in some embodiments. Figure 2 , the control method of the refrigeration system provided in the embodiment of the present application includes:

[0073] S1, obtaining the current superheat and the lower limit of the superheat of the compressor 10;

[0074] Appropriate superheat can avoid liquid in the return air of the compressor 10. The current superheat of the compressor 10 can be the current exhaust superheat of the compressor 10 or the current return air superheat of the compressor 10. An exhaust temperature sensor and an exhaust pressure sensor can be set on the exhaust pipe of the compressor 10 to detect the exhaust superheat. Specifically, the temperature value detected by the exhaust temperature sensor is recorded as W1, and the pressure value detected by the exhaust pressure sensor is recorded as P1. According to the corresponding relationship between the refrigerant saturation temperature and the saturation pressure, the saturation temperature w1 corresponding to the pressure value P1 is determined, and the difference between W1 and w1 can be determined as the exhaust superheat.

[0075] Similarly, a return air temperature sensor and a return air pressure sensor may be provided on the return air pipe of the compressor 10 to detect the return air superheat. Specifically, the temperature value detected by the return air temperature sensor is recorded as W2, and the pressure value detected by the return air pressure sensor is recorded as P2. According to the corresponding relationship between the refrigerant saturation temperature and the saturation pressure, the saturation temperature w2 corresponding to the pressure value P2 is determined, and the difference between W2 and w2 can be determined as the return air superheat.

[0076] If the current superheat is the exhaust gas superheat, the lower limit of the superheat is the exhaust gas superheat lower limit, for example, the exhaust gas superheat lower limit can be set to 25° C. If the current superheat is the return gas superheat, the lower limit of the superheat is the return gas superheat lower limit, for example, the return gas superheat lower limit can be set to 5° C.

[0077] S2. Determine whether the refrigeration system 100 meets the superheat adjustment condition according to the current superheat and the lower limit of the superheat, where the superheat adjustment condition is used to characterize the return gas from the compressor 10 with liquid;

[0078] Specifically, if the current superheat is not lower than the lower limit of the superheat, it means that the return air of the compressor 10 does not contain liquid, and it is determined that the refrigeration system 100 does not meet the superheat adjustment condition. If the current superheat is lower than the lower limit of the superheat, it means that the return air of the compressor 10 contains liquid, and it is determined that the refrigeration system 100 meets the superheat adjustment condition.

[0079] S3. If the refrigeration system 100 meets the superheat adjustment conditions, it enters the control mode, which includes the main throttle control mode and the regulating valve control mode; wherein, in the main throttle control mode, the opening of the main throttle 30 is lowered; in the regulating valve control mode, the opening of the regulating valve 21 is lowered.

[0080] When there is liquid in the return air of the compressor 10, it can be improved by adjusting the opening of the main throttle 30 and the opening of the regulating valve 21. The opening of the main throttle 30 can adjust the refrigerant flow on the circulation loop S. Under normal circumstances, by lowering the opening of the main throttle 30, the flow of liquid refrigerant formed after throttling and cooling by the main throttle 30 is reduced, and the content of liquid refrigerant entering the evaporator 40 is reduced, thereby reducing the amount of liquid refrigerant returning to the compressor 10 and improving the liquid in the return air of the compressor 10.

[0081] Adjusting the opening of the regulating valve 21 can change the flow of the coolant flowing on the cooling flow path L1, thereby adjusting the heat exchange capacity of the condenser 20. When the opening of the regulating valve 21 is lowered, the flow of the coolant on the cooling flow path L1 is reduced, the heat exchange efficiency of the condenser 20 for the high-temperature and high-pressure gaseous refrigerant discharged from the compressor 10 is reduced, the temperature of the refrigerant flowing out of the condenser 20 increases, and the content of the gaseous refrigerant increases and the content of the liquid refrigerant decreases in the refrigerant after throttling and cooling by the main throttling device 30, so that the content of the liquid refrigerant entering the evaporator 40 is reduced, thereby reducing the amount of liquid refrigerant returning to the compressor 10, and improving the return gas carrying liquid from the compressor 10.

[0082] In the embodiment of the present application, whether the return air of the compressor 10 carries liquid is judged by the superheat of the compressor 10. When it is judged that the return air of the compressor 10 carries liquid, the liquid refrigerant content entering the compressor 10 is reduced by two fine-tuning means, namely, lowering the opening of the main throttling member 30 on the circulation loop S and lowering the opening of the regulating valve 21 on the cooling flow path L1. This has a significant effect on improving the return air carrying liquid of the compressor 10, helps to reduce the risk of damage to the compressor 10 due to liquid hammer, and extends the service life of the compressor 10.

[0083] In an optional embodiment, step S1 specifically includes: obtaining the current superheat of the compressor 10 at every preset time interval; accordingly, step S2 specifically includes: if the current superheat obtained N times in succession is lower than the lower limit of the superheat, it is determined that the refrigeration system 100 meets the superheat adjustment condition, and N is an integer greater than 1.

[0084] Among them, N can be 2, 3, etc. The preset time can be 30s, 60s, 90s, 120s, etc. In actual application, when the refrigeration system 100 operates normally, the refrigeration system 100 obtains the current superheat of the compressor 10 at preset time intervals. If the current superheat obtained multiple times in succession is lower than the lower limit of the superheat, it means that the compressor 10 has a problem of return gas with liquid. In this way, when the compressor 10 temporarily has a return gas with liquid due to a short-term change in heat load, etc., there is no need to adjust the superheat, which can reduce program waste and help maintain the operating stability of the refrigeration system 100.

[0085] Figure 3 Schematic diagram of a control method for a refrigeration system in some other embodiments. Figure 2 Compared with the embodiment shown in the figure, the difference is that if the refrigeration system 100 meets the superheat adjustment condition, step S3 of entering the control mode includes:

[0086] S301, if the refrigeration system 100 meets the superheat adjustment condition, enter the main throttling device control mode, and determine whether the refrigeration system 100 reaches a first critical condition, the first critical condition is used to indicate that the main throttling device 30 is in a critical state that can be safely adjusted;

[0087] In the main throttle control mode, the opening of the main throttle 30 is adjusted downward to reduce the amount of liquid refrigerant entering the evaporator 40, thereby improving the return air liquid of the compressor 10. In order to ensure the normal circulation amount of the refrigerant on the circulation loop S and ensure the normal refrigeration capacity of the refrigeration system 100, the opening of the main throttle 30 often cannot be infinitely adjusted downward during the operation of the refrigeration system 100. The first critical condition is used to limit the minimum opening of the main throttle 30. When the refrigeration system 100 reaches the first critical condition, the main throttle 30 is in a critical state that can be safely regulated. When the refrigeration system 100 does not reach the first critical condition, the opening of the main throttle 30 is adjusted downward. The normal operation of the refrigeration system 100 has little effect. When the refrigeration system 100 reaches the first critical condition, if the opening of the main throttle 30 is continued to be adjusted downward, it may have an adverse effect on the normal operation of the refrigeration system 100, so it is necessary to set the first critical condition to control the minimum opening of the main throttle 30. In one example, the first critical condition is set as the opening degree of the main throttle 30 reaching its lower limit value.

[0088] S302: If the refrigeration system 100 does not reach the first critical condition and does not meet the superheat adjustment condition, then exit the main throttling device control mode;

[0089] In the main throttle control mode, during the process of lowering the opening of the main throttle 30, if the refrigeration system 100 does not meet the superheat adjustment condition and the refrigeration system 100 does not reach the first critical condition, it means that when the main throttle 30 lowers its opening value to a certain opening value within the safety control range, the current superheat reaches or exceeds the lower limit of the superheat, and the return air of the compressor 10 does not contain liquid, the main throttle control mode is exited, thereby solving the problem of return air containing liquid from the compressor 10.

[0090] S303: If the refrigeration system 100 reaches the first critical condition and satisfies the superheat adjustment condition, then exit the main throttling device adjustment mode and enter the adjustment valve adjustment mode.

[0091] In the main throttle control mode, during the process of lowering the opening of the main throttle 30, if the refrigeration system 100 reaches the first critical condition, the main throttle 30 can no longer be lowered to avoid adverse effects on the operation of the refrigeration system 100. At the same time, if the refrigeration system 100 still meets the superheat adjustment condition, that is, the compressor 10 still returns gas with liquid, then the main throttle control mode is exited and the regulating valve control mode is entered.

[0092] That is to say, when the problem of return air carrying liquid from the compressor 10 cannot be completely solved by regulating the main throttling member 30, when the refrigeration system 100 reaches the first critical condition (such as when the opening of the main throttling member 30 is lowered to its lower limit value, the regulating valve 21 is activated to regulate the heat exchange capacity of the condenser 20 to further improve the problem of return air carrying liquid from the compressor 10.

[0093] Because the main throttle 30 is located on the circulation loop S, it can directly adjust the liquid refrigerant content entering the evaporator 40. When adjusting its opening, its adjustment result can quickly and effectively improve the return gas with liquid in the compressor 10, and the speed of solving the problem of return gas with liquid in the compressor 10 is faster. Because the regulating valve 21 is set on the cooling flow path L1, it adjusts the liquid refrigerant content entering the evaporator 40 by indirectly adjusting the flow rate of the coolant. When adjusting its opening, its adjustment result has a relatively slow impact on the return gas with liquid problem of the compressor 10, and the improvement effect is general.

[0094] In this embodiment, when the refrigeration system 100 meets the superheat adjustment condition, it first enters the main throttle control mode, and by adjusting the opening of the main throttle 30, the problem of return air with liquid in the compressor 10 can be effectively and quickly improved. When the return air with liquid problem cannot be completely solved by adjusting the opening of the main throttle 30, the regulating valve 21 is enabled to adjust the opening of the regulating valve 21 to assist in improving the return air with liquid problem of the compressor 10. In this way, the return air with liquid problem of the compressor 10 can be improved more quickly and effectively without affecting the normal operation of the refrigeration system 100. Moreover, the main throttle control mode and the regulating valve control mode are performed in stages one after another, which not only simplifies the control, but also reduces system shock.

[0095] Of course, in other embodiments, when the refrigeration system 100 meets the superheat regulation condition, it can also enter the main throttling device regulation mode and the regulating valve regulation mode at the same time, or enter the regulating valve regulation mode first and then enter the main throttling device regulation mode.

[0096] Figure 4 This is a detailed flow chart of the step of lowering the opening degree of the main throttling member 30 in the control method of the refrigeration system in some embodiments. Figure 4 In some embodiments, the step of lowering the opening of the main throttle 30 includes:

[0097] S311, obtaining pressure interval information, the pressure interval information being obtained by equally dividing the pressure range formed by the maximum return air pressure and the minimum return air pressure of the compressor 10, and including a plurality of pressure intervals sorted in order according to the interval values;

[0098] The return air pressure refers to the pressure value of the refrigerant in the return air pipe connecting the compressor 10 and the evaporator 40. The return air pressure of the compressor 10 can be obtained by setting a pressure sensor at the return air pipe. The size of the return air pressure affects the operating effect and energy consumption of the compressor 10. If the return air pressure is too high, the load of the compressor 10 will increase and the efficiency of the compressor 10 will be reduced. If the return air pressure is too low, the exhaust volume of the compressor 10 will be reduced, resulting in energy waste. Therefore, it is usually required that the return air pressure of the compressor 10 is within a reasonable pressure range when the compressor 10 is running. The pressure range is limited by the maximum return air pressure and the minimum return air pressure. The maximum return air pressure and the minimum return air pressure are both set values, which can be set specifically according to the type of the compressor 10.

[0099] The pressure range defined by the maximum return air pressure and the minimum return air pressure is equally divided to obtain pressure interval information, which includes multiple pressure intervals and sorting information of each pressure interval according to the size of the interval value. Each pressure interval is sorted from small to large or from large to small according to the interval value.

[0100] For example, if the maximum return air pressure is set to 500kpa and the minimum return air pressure is set to 100kpa, the pressure range is [100kpa, 500kpa], and it is divided into equal parts of 50kpa, and eight pressure intervals can be obtained, which are sorted from small to large, namely [100kpa, 150kpa), [150kpa, 200kpa), [200kpa, 250kpa), [250kpa, 300kpa), [300kpa, 350kpa), [350kpa, 400kpa), [400kpa, 450kpa), and [450kpa, 500kpa]. The pressure interval information includes the interval value information and sorting information of the eight pressure intervals.

[0101] S312, obtaining the current return air pressure of the compressor 10, and determining the pressure interval where the current return air pressure is located as the reference interval according to the pressure interval information of the current return air pressure;

[0102] Based on the above example, if the current return air pressure of the compressor 10 is 215 kpa, which falls within the pressure range of [200 kpa, 250 kpa), the range of [200 kpa, 250 kpa) is used as the control range.

[0103] S313, determining a target interval according to the control interval and the pressure interval information; the target interval is a pressure interval whose interval value is smaller than the control interval and whose arrangement order is adjacent to the control interval;

[0104] Continuing with the above example, after determining that the control interval is [200kpa, 250kpa), the pressure interval that is adjacent to [200kpa, 250kpa) and whose interval value is less than [200kpa, 250kpa) is used as the target interval. In this example, the target interval is [150kpa, 200kpa).

[0105] S314, determining a target pressure value according to the target interval, the target pressure value belonging to the target interval; determining a first opening degree reduction according to the target pressure value and a first preset calculation rule;

[0106] The target pressure value is a pressure value in the target interval. The pressure value can be selected as the lower limit, median or upper limit of the target interval, etc., and can be set based on experience or test results. For example, if the pressure value is set to the lower limit of the target interval, when the target interval is [150kpa, 200kpa), the pressure value can be determined to be 150kpa.

[0107] After the target pressure value is determined, the first opening reduction is determined according to the target pressure value and the first preset calculation rule. The technician can determine the first preset calculation rule based on a reasonable design, and the specific calculation method is not limited here. For example, the design method of the first preset calculation rule is to take the target pressure value as the target, based on PID calculation, with the difference between the current return air pressure and the target pressure value as the input variable, and the output result as the first opening reduction.

[0108] S315, lowering the current opening of the main throttling member 30 according to the first opening reduction.

[0109] After the current opening of the main throttle 30 is reduced by the first opening reduction, the current return air pressure of the compressor 10 can be made to approach the target pressure value. Generally, the first opening reduction is a percentage, for example, if the first opening reduction is 10%, then the current opening is reduced by 10%.

[0110] It can be seen from the superheat calculation method that the return air pressure can directly affect the return air superheat of the compressor 10. In this embodiment, the pressure range allowed by the return air pressure when the compressor 10 is running is divided into multiple pressure intervals, and after the target interval is determined based on the reference interval where the current return air pressure is located, the opening of the main throttle 30 is regulated based on the target pressure value corresponding to the target interval as the target, so that the adjustment result of the main throttle 30 is more effective.

[0111] Figure 5 This is a detailed flow chart of lowering the opening of the main throttling member 30 in the control method of the refrigeration system in some other embodiments. Figure 4 Compared with the embodiment shown in the figure, the difference is that before the step S313 of determining the target interval according to the control interval and the pressure interval information, it also includes:

[0112] S316, determining whether the control interval is a lower limit interval; the lower limit interval is the pressure interval with the smallest interval value;

[0113] S317: If yes, it is determined that the refrigeration system 100 has reached the first critical condition, and the main throttling device control mode is exited;

[0114] If not, execute S313: determine the target interval according to the control interval and the pressure interval information.

[0115] The lower limit interval is the interval with the smallest value among multiple pressure intervals. In the above example, the lower limit interval is [100kpa, 150kpa). When the reference interval is the lower limit interval, it indicates that the current return air pressure of the compressor 10 is within the lower limit interval, and the target interval does not exist, and then the target pressure value and the first opening reduction cannot be determined, then it is judged that the refrigeration system 100 has reached the first critical condition, and at this time, the main throttling device control mode is exited to maintain the operating stability of the refrigeration system 100. When the reference interval is not the lower limit interval, step S313 is executed to determine the target interval, the target pressure value and the first opening reduction, and the opening of the main throttling device 30 is adjusted downward.

[0116] In this way, when the current return air pressure of the compressor 10 is in the lower limit interval, the main throttling device 30 can be stopped to prevent the compressor 10 from operating below the lower limit return air pressure, thereby ensuring that the compressor 10 is in a normal operating state.

[0117] Figure 6 This is a detailed flow chart of lowering the opening of the main throttling member 30 in the control method of the refrigeration system in some other embodiments. Figure 5 Compared with the embodiment shown in the figure, the difference is that after the step S315 of decreasing the current opening of the main throttle member 30 according to the first opening, the step further includes:

[0118] S318, controlling the first working duration of the main throttle member 30 according to the current opening of the main throttle member 30 after adjustment;

[0119] S319: If the refrigeration system 100 meets the superheat adjustment condition, return to execute S312: obtain the current return air pressure of the compressor 10, and determine the pressure interval in which the current return air pressure is located as the reference interval according to the pressure interval information of the current return air pressure.

[0120] In this embodiment, each time the opening of the main throttling member 30 is lowered, the first time length (such as 1 minute, 2 minutes, 3 minutes, 4 minutes, 5 minutes) is maintained, so that the refrigeration system 100 runs stably, and then it is re-judged whether the refrigeration system 100 meets the superheat adjustment condition, and the judgment result is more accurate. If it is satisfied, it means that the adjustment is not in place, and then the step S312 is returned to continue to lower the opening of the main throttling member 30.

[0121] In this way, when the problem of liquid in the return air of the compressor 10 is solved and the main throttling device 30 is within the safe control range, the opening of the main throttling device 30 can be gradually reduced multiple times, and the adjustment process is smoother, which is more conducive to the operating stability of the refrigeration system 100.

[0122] Understandably, after step S318, it further includes: if the refrigeration system 100 does not meet the superheat adjustment condition, then exit the main throttling device control mode. In other words, when the problem of liquid in the return air of the compressor 10 is solved by adjusting the opening of the main throttling device 30 within the safe control range, then exit the main throttling device control mode.

[0123] Figure 7 Detailed flow chart of lowering the opening of the regulating valve 21 in the control method of the refrigeration system in some embodiments. Figure 7 In some embodiments, the step of lowering the opening of the regulating valve 21 includes:

[0124] S321, obtaining a target exhaust superheat;

[0125] The target exhaust superheat is a preset value, and the target exhaust superheat may be the exhaust superheat lower limit value, or other set values ​​exceeding the exhaust superheat lower limit value.

[0126] S322, obtaining the current exhaust gas superheat of the compressor 10;

[0127] The current exhaust gas superheat of the compressor 10 may be acquired in the manner described in the above embodiment, which will not be described in detail here.

[0128] S323, determining a second opening degree reduction according to a difference between the target exhaust superheat and the current exhaust superheat and based on a second preset calculation rule;

[0129] Specifically, the second preset calculation rule may be to calculate the second opening degree reduction based on the PID control logic according to the difference between the target exhaust superheat and the current exhaust superheat. The specific design of the PID control logic may be conventionally set and is not specifically limited here.

[0130] S324, reducing the current opening of the regulating valve 21 by the second opening amount.

[0131] Usually, the second opening degree reduction is a percentage. For example, if the second opening degree reduction is 10%, then based on the current opening degree of the regulating valve 21 , the opening degree can be reduced by 10%.

[0132] There is a negative correlation between the exhaust superheat of the compressor 10 and the opening of the regulating valve 21. The smaller the opening of the regulating valve 21, the higher the exhaust superheat. At this time, the exhaust superheat of the compressor 10 can reflect whether the return air of the compressor 10 carries liquid. The opening of the regulating valve 21 is regulated by the change of the exhaust superheat, and the regulation result is direct and reliable.

[0133] Figure 8 Detailed flow chart of lowering the opening of the regulating valve 21 in the control method of the refrigeration system in other embodiments. Figure 7 Compared with the embodiment shown in the figure, the difference is that after the step S324 of decreasing the current opening of the regulating valve 21 by the second opening, the following step is further included:

[0134] S325, controlling the regulating valve 21 to work for a second time period according to the current opening of the regulating valve 21 after adjustment;

[0135] S326: If the refrigeration system 100 meets the superheat adjustment condition and does not meet the second critical condition, return to execute S322: obtain the current exhaust superheat of the compressor 10;

[0136] Among them, the second critical condition is used to characterize that the regulating valve 21 is in a critical state that can be safely controlled, including at least one of the current opening of the regulating valve 21 being lower than the lower limit of the opening of the regulating valve 21, the current exhaust pressure of the compressor 10 being higher than the upper limit of the exhaust pressure, and the current exhaust superheat of the compressor 10 being higher than the upper limit of the exhaust superheat.

[0137] In this embodiment, each time the opening of the regulating valve 21 is lowered, it is maintained for a second time period (such as 1 minute, 2 minutes, 3 minutes, 4 minutes, or 5 minutes) so that the refrigeration system 100 runs stably. Then, it is re-judged whether the refrigeration system 100 meets the superheat adjustment condition and whether it reaches the second critical condition. The judgment result is more accurate.

[0138] The second critical condition may be that the opening of the regulating valve 21 reaches the lower limit of the opening, or the current exhaust pressure of the compressor 10 is higher than the upper limit of the exhaust pressure, or the current exhaust superheat of the compressor 10 is higher than the upper limit of the exhaust superheat. Excessive exhaust pressure and exhaust superheat will have an adverse effect on the operation of the compressor 10 and may easily damage the compressor 10. If the opening of the regulating valve 21 is too small, it will affect the refrigeration capacity of the refrigeration system 100 and will be detrimental to the normal operation of the refrigeration system 100. Therefore, when the refrigeration system 100 reaches the second critical condition, it means that the critical state in which the regulating valve 21 can be safely regulated has been reached. If the regulating valve 21 continues to be lowered when the refrigeration system 100 reaches the second critical condition, it may cause adverse consequences for the normal operation of the refrigeration system 100.

[0139] If the refrigeration system 100 does not meet the superheat adjustment condition, it means that the return air of the compressor 10 does not contain liquid, indicating that the adjustment is in place, and the regulating valve control mode is exited.

[0140] When the refrigeration system 100 satisfies the superheat adjustment condition and has not reached the second critical condition, it means that the regulating valve 21 is within the safe control range, and the problem of return air carrying liquid from the compressor 10 is continued to be improved by lowering the opening of the regulating valve 21. Then, the process returns to step S322, reacquires the current exhaust superheat of the compressor 10, recalculates the second opening reduction, and continues to lower the opening of the regulating valve 21.

[0141] In this way, when the regulating valve 21 is within the safe control range to solve the problem of liquid in the return air of the compressor 10, the opening of the regulating valve 21 can be gradually reduced multiple times, and the adjustment process is smoother, which is more conducive to the operation stability of the refrigeration system 100.

[0142] Fig. 9 Schematic diagram of a control method for a refrigeration system in some other embodiments. Figure 3 Compared with the embodiment shown in the figure, the difference is that if the refrigeration system 100 reaches the first critical condition and satisfies the superheat adjustment condition, then after exiting the main throttling device control mode and entering the regulating valve control mode in step S303, it also includes:

[0143] S4. If the refrigeration system 100 reaches the second critical condition and satisfies the superheat adjustment condition, exit the regulating valve control mode and enter the refrigerant temperature control mode until the refrigeration system 100 does not meet the superheat adjustment condition; in the refrigerant temperature control mode, control the refrigeration system 100 to increase the return air temperature of the compressor 10.

[0144] As shown above, when the refrigeration system 100 reaches the second critical condition, the opening of the regulating valve 21 cannot be further reduced, otherwise it will bring adverse consequences to the stable operation of the refrigeration system 100. If the refrigeration system 100 still meets the superheat adjustment condition at this time, it means that reducing the opening of the regulating valve 21 cannot solve the problem of liquid in the return air of the compressor 10, and then enter the refrigerant temperature control mode, and further improve the liquid in the return air of the compressor 10 by increasing the return air temperature of the compressor 10.

[0145] The return air temperature of the compressor 10 refers to the temperature of the refrigerant flowing through the return air pipe of the compressor 10. The higher the return air temperature of the compressor 10, the less liquid refrigerant there is in the return air pipe and the more gaseous refrigerant there is. By increasing the return air temperature of the compressor 10, the problem of liquid in the return air of the compressor 10 can be improved.

[0146] In actual application, if the return air of the compressor 10 still contains liquid after being adjusted by the regulating valve 21, the common reason is that the refrigeration system 100 is in an abnormal operating state, for example, the heat load is cancelled. At this time, the refrigerant temperature control mode is entered to solve the problem of return air containing liquid by increasing the return air temperature of the compressor 10. The adjustment force is large, which can protect the refrigeration system 100 from downtime.

[0147] In order to increase the return air temperature of the compressor 10, a heater may be provided at the return air pipe to gasify the liquid refrigerant in the return air pipe. Alternatively, the solution in the following embodiment may be adopted.

[0148] Figures 10 to 12 Schematic diagrams of components of refrigeration systems 100 according to other various embodiments.

[0149] Reference Fig.10 and Fig.11 In some embodiments, the circulation loop S includes a return air main path S1 located between the outlet side of the evaporator 40 and the compressor 10, and the refrigeration system 100 includes a return air bypass path H arranged in parallel with the return air main path S1, and a regenerator 60 is arranged on the return air bypass path H, and the regenerator 60 has a heat recovery flow path L2 for heating the return air bypass path H. A first control valve f1 is arranged on the return air bypass path H between the regenerator 60 and the evaporator 40, and a second control valve f2 is arranged on the return air main path S1. The heat recovery flow path L2 is composed of a flow path located between the compressor 10 and the condenser 20 in the circulation loop S, or the heat recovery flow path L2 is composed of the cooling flow path L1, and in the coolant flow direction of the cooling flow path L1, the regenerator 60 is located downstream of the condenser 20.

[0150] like Fig.10 As shown, the flow path between the compressor 10 and the condenser 20 serves as the heat recovery flow path L2. The high-temperature refrigerant discharged from the compressor 10 exchanges heat with the return air bypass H when flowing through the regenerator 60, thereby heating the refrigerant on the return air bypass H to increase the return air temperature of the compressor 10.

[0151] like Fig.11 As shown, the cooling flow path L1 of the condenser 20 serves as the heat recovery flow path L2. The coolant on the cooling flow path L1 absorbs the high-temperature refrigerant flowing through the condenser 20 and its temperature rises. Then, when flowing through the heat regenerator 60, it exchanges heat with the return air bypass H, heating the refrigerant on the return air bypass H to increase the return air temperature of the compressor 10.

[0152] A first control valve f1 is provided on the return air bypass H, and a second control valve f2 is provided on the return air main path S1, and the two are not connected at the same time. When entering the refrigerant control mode, it is necessary to increase the return air temperature, and the return air refrigerant is required to return to the compressor 10 through the return air bypass H. At this time, the second control valve f2 is closed and the first control valve f1 is opened. When exiting the refrigerant control mode, the first control valve f1 is closed, the second control valve f2 is opened, and the refrigeration system 100 operates normally.

[0153] In this embodiment, by setting up a return air bypass H in parallel with the return air main path S1, in the refrigerant temperature control mode, the return air refrigerant flowing through the return air bypass H can be heated and heated by the heat regenerator 60 using the temperature of the high-temperature refrigerant on the circulation loop S or by using the heated coolant, thereby directly vaporizing the liquid components in the return air refrigerant. This can not only effectively solve the problem of liquid in the return air of the compressor 10, but also is more energy-efficient.

[0154] In some embodiments, based on the structural composition of the refrigeration system 100 described above, in step S4, the refrigeration system 100 is controlled to increase the return air temperature of the compressor 10, including: opening the first control valve f1 and closing the second control valve f2.

[0155] In this way, when the refrigerant flowing to the return air end of the compressor 10 flows through the return air bypass H, it can exchange heat with the heat recovery flow path L2 of the regenerator 60. The return air refrigerant is heated and heated by the heating medium flowing through the regenerator 60, and the liquid refrigerant in the return air refrigerant is vaporized, thereby reducing the liquid refrigerant content returning to the compressor 10, thereby improving and solving the problem of liquid in the return air of the compressor 10.

[0156] Understandably, after the first control valve f1 is opened, when the refrigeration system 100 does not meet the superheat adjustment condition, that is, the compressor 10 does not return gas with liquid, the first control valve f1 is closed and the second control valve f2 is switched from the closed state to the open state.

[0157] Reference Fig.12 In other embodiments, the refrigeration system 100 includes a throttling bypass J connected to the inlet side of the condenser 20 and the outlet side of the main throttling device 30, and the throttling bypass J is provided with a secondary throttling device 70.

[0158] The inlet end of the throttling bypass J is directly connected to the exhaust end of the compressor 10. In the refrigerant temperature control mode, a part of the high-temperature refrigerant discharged from the compressor 10 flows through the condenser 20 and the main throttling device 30 along the circulation loop S to obtain the first throttling refrigerant; the other part of the high-temperature refrigerant is diverted to the throttling bypass J, and after throttling and cooling by the secondary throttling device 70, the second throttling refrigerant is obtained. The temperature of the first throttling refrigerant is lower than that of the second throttling refrigerant. The two are mixed before entering the evaporator 40, so that the refrigerant dryness of the refrigerant entering the evaporator 40 increases. The higher the refrigerant dryness, the higher the gas phase refrigerant content, the lower the heat exchange between the evaporator 40 and the outside, the refrigerant temperature flowing out of the evaporator 40 increases and the gas phase component is higher, which can increase the return air temperature of the compressor 10 and improve the return air liquid of the compressor 10.

[0159] Refrigerant dryness refers to the weight ratio of gaseous phase refrigerant in a unit mass of refrigerant. The refrigerant dryness can be calculated by the inlet pressure and inlet temperature of the refrigerant at the inlet side of the evaporator 40. The closer the refrigerant dryness is to 1, the higher the gas phase component of the refrigerant. In actual settings, it is possible to determine whether the refrigeration system 100 does not meet the superheat adjustment condition by detecting whether the refrigerant dryness reaches the target value. The target value of the refrigerant dryness can be 1. Specifically, when the inlet temperature exceeds the saturation temperature corresponding to the inlet pressure, it means that the refrigerant dryness reaches 1. Understandably, when the refrigerant dryness reaches 1, the gas phase component in the refrigerant is 100%, no liquid refrigerant enters the evaporator 40, and no liquid refrigerant flows out of the evaporator 40, so that the return air of the compressor 10 is liquid-free, and the refrigeration system 100 does not meet the superheat adjustment condition.

[0160] Of course, the target value of the refrigerant dryness may also be other reasonable values, which may be set specifically based on actual experience or experiments.

[0161] In some embodiments, based on the structural composition of the refrigeration system 100 , in step S4 , controlling the refrigeration system 100 to increase the return air temperature of the compressor 10 includes: opening the secondary throttling device 70 .

[0162] The high-temperature refrigerant discharged from the compressor 10 is slightly cooled by the secondary throttling device 70, and then the refrigerant on the circulation loop S is heated to reduce the content of liquid refrigerant entering the evaporator 40, increase the content of gas refrigerant flowing out of the evaporator 40, and increase the return air temperature of the compressor 10.

[0163] At this time, the secondary throttling device 70 and the throttling bypass J are provided to increase the refrigerant dryness at the inlet side of the evaporator 40, thereby increasing the return air temperature of the compressor 10. The configuration cost is low and it is more energy-saving.

[0164] It can be understood that the refrigeration system 100 provided in the embodiment of the present application can execute the control method in any of the above embodiments, and it has the beneficial effects recorded in the above embodiments, which will not be repeated here.

[0165] Specifically, the refrigeration system 100 further includes a controller, which is connected to the regulating valve 21, the primary throttle 30, the secondary throttle 70, the first control valve f1, the second control valve f2, etc. in the above embodiment. The controller can execute the control method of the refrigeration system in the above embodiment. The controller can be a device or apparatus with data processing, communication, etc., such as a central processing unit, a microprocessor, an embedded single-chip microcomputer, a computer, a mobile intelligent terminal, etc.

[0166] In addition, the test device provided in the embodiment of the present application includes a test terminal and the refrigeration system 100 in the above embodiment, and the refrigeration system 100 is used to adjust the temperature of the test terminal. The test device has the beneficial effects in the above embodiment, which will not be repeated here.

[0167] Typically, the test equipment further includes a heating device, which works together with the refrigeration system 100 to adjust the temperature of the test terminal. The setting of the heating device can refer to conventional settings and is not limited here.

[0168] The test equipment may be a sorting test equipment, a probe station equipment, an aging test equipment, etc., which are used for performance testing of semiconductor devices such as chips or wafers. The test terminal may be a test pressure head, a test cavity, a preheating plate, a material shuttle, a wafer carrier plate, etc. The test cavity is a cavity structure for providing a test space, and a plurality of chips or wafers may be stored in the test space. The evaporator 40 of the refrigeration system 100 may be arranged in the test space to adjust the test temperature of the test space. The test pressure head refers to a pressure head structure that can press down and abut against the chip, which is in direct contact with the chip to regulate the temperature of the chip. A refrigerant flow path may be provided in the evaporator 40 of the refrigeration system 100, and the refrigerant in the refrigerant flow path is cooled by the refrigerant flowing through the evaporator 40. The refrigerant flow path may be connected to a pipeline in the test pressure head, and the temperature of the test pressure head is adjusted by the refrigerant. The preheating plate refers to a structure that carries the chip and adjusts the temperature of the chip. The refrigerant flow path may be connected to the pipeline of the preheating plate, and the temperature of the preheating plate is adjusted by the refrigerant. The shuttle is a structure for transporting chips. The coolant flow path can be connected to the pipeline inside the shuttle, and the temperature of the shuttle is adjusted by the coolant. The wafer carrier is a structure for carrying wafers by adsorption. The coolant flow path can be connected to the pipeline inside the wafer carrier, and the test temperature of the wafer is adjusted by the coolant.

[0169] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, 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, they should be considered to be within the scope of this specification.

[0170] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A control method for a refrigeration system, characterized in that: The refrigeration system comprises a compressor (10), a condenser (20), a main throttle (30) and an evaporator (40) which are sequentially connected to form a circulation loop (S); the condenser (20) comprises a cooling flow path (L1) for circulating an external coolant; and a regulating valve (21) is provided on the cooling flow path (L1); The control method comprises: Obtaining the current superheat and the lower limit value of the superheat of the compressor (10); Determining whether the refrigeration system satisfies a superheat adjustment condition according to the current superheat and the superheat lower limit value, wherein the superheat adjustment condition is used to characterize liquid in the return air of the compressor (10); If the refrigeration system meets the superheat adjustment condition, it enters the control mode, and the control mode includes the main throttle control mode and the regulating valve control mode; Wherein, in the main throttling element control mode, the opening of the main throttling element (30) is adjusted downward; in the regulating valve control mode, the opening of the regulating valve (21) is adjusted downward.

2. The control method of the refrigeration system according to claim 1, characterized in that: If the refrigeration system meets the superheat adjustment condition, the control mode is entered, including: If the refrigeration system meets the superheat adjustment condition, the main throttling device adjustment mode is entered, and it is determined whether the refrigeration system reaches a first critical condition, wherein the first critical condition is used to indicate that the main throttling device (30) is in a critical state that can be safely adjusted; If the refrigeration system does not reach the first critical condition and does not meet the superheat adjustment condition, then exit the main throttling device control mode; If the refrigeration system reaches the first critical condition and satisfies the superheat adjustment condition, the main throttling element adjustment mode is exited and the adjustment valve adjustment mode is entered.

3. The control method of a refrigeration system according to claim 1 or 2, characterized in that: Lowering the opening of the main throttling member (30) comprises: Acquiring pressure interval information, the pressure interval information being obtained by equally dividing the pressure range formed by the maximum return air pressure and the minimum return air pressure of the compressor (10), and including a plurality of pressure intervals sorted in order according to the size of the interval values; Acquiring a current return air pressure of the compressor (10), and determining, based on the current return air pressure, from the pressure interval information, the pressure interval in which the current return air pressure is located as a control interval; Determine a target interval according to the control interval and the pressure interval information; the target interval is the pressure interval whose interval value is smaller than the control interval and whose arrangement order is adjacent to the control interval; Determine a target pressure value according to the target interval, the target pressure value belongs to the target interval; determine a first opening degree reduction according to the target pressure value and a first preset calculation rule; The current opening of the main throttling member (30) is adjusted downward according to the first opening reduction.

4. The control method of the refrigeration system according to claim 3, characterized in that: Before determining the target interval according to the control interval and the pressure interval information, the method further includes: Determine whether the control interval is a lower limit interval; the lower limit interval is the pressure interval with the smallest interval value; If yes, it is determined that the refrigeration system has reached a first critical condition, and the main throttling device control mode is exited; If not, executing: determining a target interval according to the control interval and the pressure interval information.

5. The control method of the refrigeration system according to claim 4, characterized in that: After the current opening of the main throttling member (30) is reduced according to the first opening, the method further comprises: controlling the first working duration of the main throttling member (30) according to the current opening degree of the main throttling member (30) after adjustment; If the refrigeration system meets the superheat adjustment condition, the process returns to the following steps: obtaining the current return air pressure of the compressor (10), and determining, based on the current return air pressure, from the pressure interval information, that the pressure interval in which the current return air pressure is located is a control interval.

6. The control method of a refrigeration system according to claim 1 or 2, characterized in that: Lowering the opening of the regulating valve (21) comprises: Obtaining target exhaust superheat; Obtaining the current exhaust gas superheat of the compressor (10); Determining a second opening degree reduction according to a difference between the target exhaust superheat and the current exhaust superheat and based on a second preset calculation rule; The current opening degree of the regulating valve (21) is adjusted downward by the second opening degree reduction.

7. The control method of the refrigeration system according to claim 6, characterized in that: After the current opening of the regulating valve (21) is reduced by the second opening, the method further comprises: controlling the regulating valve (21) to work for a second time period according to the current opening of the regulating valve (21) after adjustment; If the refrigeration system satisfies the superheat adjustment condition and does not reach the second critical condition, the process returns to the execution of: obtaining the current exhaust gas superheat of the compressor (10); The second critical condition is used to characterize that the regulating valve (21) is in a critical state that can be safely controlled, including at least one of the following: the current opening of the regulating valve (21) is lower than the lower limit of the opening of the regulating valve (21), the current exhaust pressure of the compressor (10) is higher than the upper limit of the exhaust pressure, and the current exhaust superheat of the compressor (10) is higher than the upper limit of the exhaust superheat.

8. The control method of a refrigeration system according to claim 2, characterized in that: If the refrigeration system reaches the first critical condition and satisfies the superheat adjustment condition, then the main throttling device control mode is exited and the regulating valve control mode is entered, further comprising: If the refrigeration system reaches the second critical condition and satisfies the superheat adjustment condition, the regulating valve control mode is exited and the refrigerant temperature control mode is entered until the refrigeration system no longer satisfies the superheat adjustment condition; in the refrigerant temperature control mode, the refrigeration system is controlled to increase the return air temperature of the compressor (10).

9. The control method of the refrigeration system according to claim 8, characterized in that: The circulation loop (S) comprises a return air main path (S1) located between the outlet side of the evaporator (40) and the compressor (10); the refrigeration system comprises a return air bypass path (H) arranged in parallel with the return air main path (S1); a regenerator (60) is arranged on the return air bypass path (H); the regenerator (60) has a heat recovery flow path (L2) for heating the return air bypass path (H); a first control valve (f1) is arranged on the return air bypass path (H) between the regenerator (60) and the evaporator (40); the return air main path (S1) ) is provided with a second control valve (f2); the heat recovery flow path (L2) is composed of a flow path between the compressor (10) and the condenser (20) in the circulation loop (S), or the heat recovery flow path (L2) is composed of the cooling flow path (L1), and in the coolant flow direction of the cooling flow path (L1), the heat regenerator (60) is located downstream of the condenser (20); controlling the refrigeration system to increase the return air temperature of the compressor (10) comprises: opening the first control valve (f1) and closing the second control valve (f2); And / or, the refrigeration system includes a throttling bypass (J) connected to the inlet side of the condenser (20) and the outlet side of the main throttling device (30), and a secondary throttling device (70) is arranged on the throttling bypass (J); and controlling the refrigeration system to increase the return air temperature of the compressor (10) includes: opening the secondary throttling device (70).

10. A refrigeration system, characterized in that: The refrigeration system comprises a compressor (10), a condenser (20), a main throttling device (30) and an evaporator (40) which are connected in sequence to form a circulation loop (S), the condenser (20) comprising a cooling flow path (L1) for circulating an external coolant, and a regulating valve (21) is arranged on the cooling flow path (L1); the refrigeration system is capable of executing the control method according to any one of claims 1 to 9.

11. A testing device, characterized in that: It comprises a test terminal and a refrigeration system as claimed in claim 10, wherein the refrigeration system is used to adjust the temperature of the test terminal.

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