Auto-cascade semiconductor temperature control system with pre-cooling function and control method of auto-cascade semiconductor temperature control system

Abstract

The invention relates to the technical field of temperature control systems special for semiconductors in the integrated circuit industry, and provides an auto-cascade semiconductor temperature control system with a pre-cooling function and a control method thereof.The auto-cascade semiconductor temperature control system with the pre-cooling function comprises a circulating liquid subsystem, a pre-cooling subsystem and an auto-cascade subsystem; the pre-cooling subsystem comprises a first evaporator and a pre-cooling compressor, and the pre-cooling subsystem is connected with the circulating liquid subsystem through the first evaporator; the auto-cascade subsystem comprises an auto-cascade compressor, a second evaporator and a condensing evaporator, the auto-cascade subsystem is connected with the circulating liquid subsystem through the second evaporator, and the auto-cascade subsystem is connected with the pre-cooling subsystem through the condensing evaporator. The application range of the auto-cascade refrigeration system is widened, the auto-cascade refrigeration system can stably operate in a high-temperature area of + 80 DEG C to-40 DEG C, the auto-cascade refrigeration system can also stably operate in a temperature range of-140 DEG C to-40 DEG C, and the risk of shutdown due to overpressure when the auto-cascade refrigeration system is started and the phenomenon that the pressure of the auto-cascade subsystem is too high in the cooling process are reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor-specific temperature control systems in the integrated circuit industry, and in particular to a self-cascaded semiconductor temperature control system with precooling and a control method thereof. Background Art

[0002] During the etching process of semiconductor wafers, in order to control the etching accuracy, the temperature in the processing chamber needs to be precisely controlled. Etching equipment often needs to be equipped with special temperature control equipment. With the rapid development of the semiconductor manufacturing industry and the increasing complexity of the process, conventional temperature control devices in the temperature range above -70°C will gradually fail to meet the needs of process development. At present, temperature control devices in the low-temperature range below -70°C mainly include two forms: one is the use of a traditional three-stage cascade refrigeration system to meet -80~-120°C, which solves the temperature range problem, but because three sets of refrigeration systems need to be cascaded for cooling, the size, energy consumption, and cost of such temperature control devices are generally very high, and the control logic is complex, the failure rate is high, and the energy efficiency ratio is low, so they cannot be put into use on a large scale. The other is to use a self-cascade subsystem to meet the low temperature requirements of -40~-140℃. Although it solves the shortcomings of the three-stage cascade system, such as complex control logic, high volume, energy consumption, cost, and low energy efficiency, it requires the use of a multi-mixed refrigerant for refrigeration. When the condensation temperature of the low-boiling-point refrigerant in the mixed refrigerant is high, the low-boiling-point components in the mixed refrigerant will generate a high pressure. The instantaneous startup of the system will cause the compressor load to increase and shut down. In addition, the pressure of the conventional self-cascade subsystem is generally high during the cooling process, which reduces the service life of system components and makes the system reliability relatively poor. Summary of the invention

[0003] The present invention provides a self-cascade semiconductor temperature control system with pre-cooling and a control method thereof, so as to solve the defects of the ultra-low temperature temperature control system in the prior art, such as complex composition, high energy consumption and poor stability, and improve the application range of the self-cascade refrigeration system. The self-cascade refrigeration system can be stably operated in the high temperature zone of +80°C to -40°C, and can also be stably operated in the temperature zone of -140°C to -40°C, thereby reducing the risk of shutdown due to overpressure at startup and the phenomenon of high pressure of the self-cascade subsystem during the cooling process.

[0004] The present invention provides a self-cascade semiconductor temperature control system with precooling, comprising: A circulating liquid subsystem, the circulating liquid subsystem is connected to the main equipment, and the circulating liquid subsystem is used to provide the main equipment with circulating liquid after cooling; A precooling subsystem, the precooling subsystem comprising a first evaporator and a precooling compressor, the first evaporator and the precooling compressor are connected, and the precooling subsystem is connected to the circulating liquid subsystem through the first evaporator; The self-cascade subsystem includes a self-cascade compressor, a second evaporator and a condensing evaporator. The self-cascade compressor is connected to the condensing evaporator and the second evaporator. The self-cascade subsystem is connected to the circulating liquid subsystem through the second evaporator. The self-cascade subsystem is connected to the precooling subsystem through the condensing evaporator.

[0005] According to a self-cascade semiconductor temperature control system with precooling provided by the present invention, the self-cascade subsystem includes a condenser and a first refrigeration circuit and a second refrigeration circuit, the first refrigeration circuit is connected between the condenser evaporator and the condenser, and the second refrigeration circuit is connected between the second evaporator and the condenser.

[0006] According to a self-cascade semiconductor temperature control system with precooling provided by the present invention, the circulating liquid subsystem includes a first circulating branch and a second circulating branch, the first circulating branch is connected to the first evaporator, the second circulating branch is connected to the second evaporator, the first circulating branch and the second circulating branch are connected in parallel through a first three-way valve and a second three-way valve, and are connected to the main equipment.

[0007] According to a self-cascade semiconductor temperature control system with precooling provided by the present invention, the precooling subsystem includes a condenser, a first precooling circuit and a second precooling circuit, the condenser is connected to the front end of the precooling compressor, the first precooling circuit is connected between the condenser and the first evaporator and the precooling compressor, and the second precooling circuit is connected between the condenser evaporator and the condenser.

[0008] According to a self-cascade semiconductor temperature control system with precooling provided by the present invention, the precooling subsystem also includes a first cold spray branch, the first cold spray branch is connected to the rear end of the precooling compressor and the front end of the condenser, the first cold spray branch is provided with a first cold spray solenoid valve and a cold spray thermal expansion valve, the rear end of the precooling compressor is provided with a precooling exhaust temperature sensor, when the precooling exhaust temperature sensor exceeds a set threshold value, the first cold spray solenoid valve is opened, and at the same time, the opening of the cold spray thermal expansion valve is controlled in real time according to the exhaust temperature measured by the precooling exhaust temperature sensor.

[0009] According to a self-cascade semiconductor temperature control system with precooling provided by the present invention, a first refrigeration electronic pulse valve and a first refrigeration thermal expansion valve are provided on the first precooling circuit, the first refrigeration electronic pulse valve is used to allow refrigerant to flow from the condenser into the first evaporator, and the first refrigeration thermal expansion valve adjusts its own opening according to the superheat of the first evaporator to adjust the real-time flow to the first evaporator.

[0010] According to a self-cascade semiconductor temperature control system with precooling provided by the present invention, the self-cascade subsystem also includes a second cold spray branch, the second cold spray branch is connected between the self-cascade compressor and the condenser separator, a second cold spray solenoid valve and a first capillary are provided on the second cold spray branch, and a self-cascade exhaust temperature sensor and a self-cascade exhaust pressure sensor are provided between the self-cascade compressor and the condenser evaporator; When the exhaust temperature monitored by the self-cascade exhaust temperature sensor exceeds a preset value Tb, the second cold spray solenoid valve is opened to throttle and cool the exhaust gas through the first capillary tube; When the exhaust temperature monitored by the self-cascaded exhaust temperature sensor is lower than the preset value Tb, it is closed after a delay of ns.

[0011] According to a precooling auto-cascade semiconductor temperature control system provided by the present invention, the auto-cascade further comprises a gas storage branch, the gas storage branch is connected between the auto-cascade compressor and the condenser separator, the gas storage branch is provided with a gas storage tank, an exhaust valve and an intake valve, the intake valve is connected between the gas storage tank and the condenser evaporator, the exhaust valve is connected between the gas storage tank and the auto-cascade compressor, a auto-cascade exhaust pressure sensor is further provided between the auto-cascade compressor and the condenser evaporator, and a liquid supply temperature sensor is provided on the circulating liquid subsystem; In the process of throttling and cooling through the first capillary tube, when the exhaust pressure monitored by the self-cascaded exhaust pressure sensor exceeds the set value Pv1, the intake valve is opened to release pressure; When the exhaust pressure monitored by the self-cascaded exhaust pressure sensor is lower than the set value Pv1, the intake valve is closed; When the real-time value monitored by the liquid supply temperature sensor drops below -40°C, the exhaust valve opens.

[0012] According to a self-cascade semiconductor temperature control system with precooling provided by the present invention, the second refrigeration circuit is provided with a third refrigeration electronic pulse valve and a capillary branch connected to both ends of the third refrigeration electronic pulse valve, and the capillary branch is provided with a second capillary tube; When the real-time value monitored by the liquid supply temperature sensor is lower than -80°C, the third refrigeration electronic pulse valve is closed, and throttling refrigeration is performed through the capillary branch.

[0013] The present invention also provides a control method for a self-cascade semiconductor temperature control system with precooling, which is applied to the self-cascade semiconductor temperature control system with precooling as described above, and the control method comprises: The temperature control device PLC receives the instructions from the main device and determines the temperature threshold preset by the main device; When the temperature threshold preset by the main device is: SV ≥ -40°C, it is determined that only the pre-cooling subsystem is running; When the preset temperature threshold of the main device is: -140℃≤SV<-40℃, it is determined that the precooling subsystem and the cascade subsystem are running simultaneously, wherein the precooling compressor is started first, and when the reading of the exhaust pressure sensor reaches the preset value, the cascade compressor is started.

[0014] The present invention provides a self-cascade semiconductor temperature control system with precooling and a control method thereof. By setting a precooling subsystem, the system can operate independently in a high temperature zone, and is connected to the circulating liquid subsystem through a first evaporator to effectively precool the circulating liquid, thereby creating a more stable working environment for the self-cascade subsystem. This reduces the pressure fluctuation caused by direct evaporation of the refrigerant in the high temperature zone, ensuring the stable operation of the system in the high temperature zone. The self-cascade subsystem operates stably within -140°C to -40°C, and is connected to the circulating liquid subsystem through a second evaporator, and is connected to the precooling subsystem through a condensing evaporator, forming an efficient refrigeration cycle. The self-cascade subsystem is allowed to operate stably at extremely low temperatures because the precooling subsystem has lowered the temperature of the refrigerant, reducing the refrigeration load and pressure at extremely low temperatures. The precooling effect of the precooling subsystem can reduce the instantaneous evaporation of the refrigerant when the self-cascade system is turned on, thereby reducing the pressure peak at startup, reducing the risk of a sudden increase in the compressor load, and avoiding system downtime due to overpressure. Since the pre-cooling subsystem lowers the temperature of the refrigerant in advance, the refrigeration capacity required by the cascade subsystem during the cooling process is reduced, so the overall pressure of the system is reduced. This ensures that the system pressure remains within a safe range during the cooling process, thereby improving the reliability of the system and the service life of the components. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the present invention or the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0016] Figure 1 It is a connection schematic diagram of the self-cascade semiconductor temperature control system with precooling provided by the present invention.

[0017] Reference numerals: 1. Precooling compressor; 2. Precooling exhaust temperature sensor; 3. Precooling oil separator; 4. First one-way valve; 5. Condenser; 6. Condensing pressure regulating valve; 7. Precooling drying filter; 8. First cold spray solenoid valve; 9. Cold spray thermal expansion valve; 10. First refrigeration electric pulse valve; 11. First refrigeration thermal expansion valve; 12. Second refrigeration electronic pulse valve; 13. Second refrigeration thermal electric expansion valve; 14. First evaporator; 15. Second one-way valve; 16. Precooling hot gas electronic expansion valve; 17. Suction pressure sensor; 21. Cascade compressor; 22. Cascade oil separator; 23. Cascade exhaust pressure sensor; 24. Cascade exhaust temperature sensor; 25. Condenser evaporator; 26. Cascade dry filter; 27. Separator; 28. Regenerator; 29. ​​Third refrigeration electronic pulse valve; 30. Fourth capillary; 31. Second capillary; 32. Third capillary; 33. Second cold spray solenoid valve; 34. First capillary; 35. Exhaust valve; 36. Third one-way valve; 37. Inlet valve; 38. Gas storage tank; 39. Cascade hot gas electronic expansion valve; 40. Flow meter; 41. First three-way valve 1; 42. Second three-way valve 2; 43. Circulation pump; 44. Heater; 45. Water tank; 46. Liquid supply temperature sensor; 47. Liquid supply pressure sensor; 48. Second evaporator; 49. Main equipment; 50. Return temperature sensor. DETAILED DESCRIPTION

[0018] The following embodiments of the present invention are described in further detail in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0019] In the description of the embodiments of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limitations on the embodiments of the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0020] In the description of the embodiments of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" 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. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific circumstances.

[0021] In the embodiments of the present invention, unless otherwise clearly specified and limited, the first feature being "above" or "below" the 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, the first feature being "above", "above" and "above" the 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. The first feature being "below", "below" and "below" the 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.

[0022] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiment of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0023] Combine the following Figure 1 , the self-cascade semiconductor temperature control system with pre-cooling and the control method thereof provided by the embodiment of the present invention are described in detail through specific embodiments and their application scenarios.

[0024] In the embodiment of the present invention, Figure 1As shown, the self-cascade semiconductor temperature control system with precooling includes a circulating liquid subsystem, a precooling subsystem and a self-cascade subsystem. The circulating liquid subsystem is connected to the main equipment 49, and the circulating liquid subsystem is used to provide the main equipment 49 with cooled circulating liquid; the precooling subsystem includes a first evaporator 14 and a precooling compressor 1, the first evaporator 14 is connected to the precooling compressor 1, and the precooling subsystem is connected to the circulating liquid subsystem through the first evaporator 14; the self-cascade subsystem includes a self-cascade compressor 21, a second evaporator 48 and a condensing evaporator 25, the self-cascade compressor 21 is connected to the condensing evaporator 25 and the second evaporator 48, the self-cascade subsystem is connected to the circulating liquid subsystem through the second evaporator 48, and the self-cascade subsystem is connected to the precooling subsystem through the condensing evaporator 25.

[0025] The circulating liquid subsystem is directly connected to the main device 49 (semiconductor etching equipment) for transmitting cooling energy to ensure the temperature of the main device 49 is stable.

[0026] The circulating fluid circulates in the system, and after being cooled by the refrigeration subsystem, it flows to the main device 49 to absorb the heat generated by the device, and then returns to the refrigeration system to continue cooling, forming a closed cycle to maintain a constant temperature of the main device 49.

[0027] The precooling subsystem includes a first evaporator 14 and a precooling compressor 1. The main function of the precooling subsystem is to precool the circulating fluid in a relatively high temperature range to reduce the refrigeration burden of the self-cascading subsystem.

[0028] The first evaporator 14 is connected to the precooling compressor 1. The precooling compressor 1 drives the refrigerant to absorb heat and evaporate in the first evaporator 14, thereby absorbing the heat of the circulating fluid to achieve a precooling effect.

[0029] The first evaporator 14 is connected to the circulating liquid subsystem and serves as an interface between the precooling subsystem and the circulating liquid subsystem to complete heat exchange.

[0030] The auto-cascade subsystem includes an auto-cascade compressor 21, a second evaporator 48 and a condensing evaporator 25. The auto-cascade subsystem is responsible for achieving refrigeration in a lower temperature range. Its design allows the use of a multi-component mixed working fluid to achieve refrigeration in a wider temperature range.

[0031] The cascade compressor 21 is connected to the condenser evaporator 25 and the second evaporator 48. The cascade compressor is the power source of the system. It compresses the refrigerant, causing it to release heat and condense in the condenser evaporator 25, and then absorb heat and evaporate in the second evaporator 48 to realize the refrigeration cycle.

[0032] The second evaporator 48 is connected to the circulating liquid subsystem. The second evaporator 48 is a key component connecting the cascade subsystem and the circulating liquid subsystem. It absorbs heat in the circulating liquid through the evaporation of the refrigerant to reduce the temperature of the circulating liquid.

[0033] The condenser evaporator 25 is connected to the precooling subsystem, and the condenser evaporator 25 serves as the condenser 5 of the self-cascade subsystem and the evaporator of the precooling subsystem at the same time, realizing energy exchange and coordinated work between the two subsystems. The refrigerant in the self-cascade subsystem releases heat in the condenser evaporator 25 and is cooled by the precooling subsystem, thereby improving the refrigeration efficiency and stability of the entire system.

[0034] The present application can operate independently in the high temperature zone by setting up a precooling subsystem, and is connected to the circulating liquid subsystem through the first evaporator 14, effectively precooling the circulating liquid, thereby creating a more stable working environment for the self-cascade subsystem. This reduces the pressure fluctuations caused by the direct evaporation of the refrigerant in the high temperature zone, ensuring the stable operation of the system in the high temperature zone. Stable operation within -140℃~-40℃, the self-cascade subsystem is connected to the circulating liquid subsystem through the second evaporator 48, and is connected to the precooling subsystem through the condensing evaporator 25, forming an efficient refrigeration cycle. The self-cascade subsystem is allowed to operate stably at extremely low temperatures because the precooling subsystem has lowered the temperature of the refrigerant and reduced the refrigeration load and pressure at extremely low temperatures. The precooling effect of the precooling subsystem can reduce the instantaneous evaporation of the refrigerant when the self-cascade system is turned on, thereby reducing the pressure peak at startup, reducing the risk of a sudden increase in the compressor load, and avoiding the system from shutting down due to overpressure. Since the precooling subsystem lowers the temperature of the refrigerant in advance, the overall pressure of the system is reduced. Ensure that the system pressure remains within a safe range during the cooling process, thereby improving system reliability and component life.

[0035] Reference Figure 1 According to the present invention, a self-cascade semiconductor temperature control system with precooling is provided. The self-cascade subsystem includes a condenser separator 27 and a first refrigeration circuit and a second refrigeration circuit. The first refrigeration circuit is connected between the condenser evaporator 25 and the condenser separator 27, and the second refrigeration circuit is connected between the second evaporator 48 and the condenser separator 27.

[0036] It is understandable that the condensation separator 27 is used to separate different components in the multi-component mixed working fluid. In the refrigeration cycle, refrigerants of different components are separated and condensed at different temperatures and pressures, thereby achieving effective heat exchange and improving refrigeration efficiency. The condensation separator 27 allows high-boiling point components and low-boiling point components to play a role at different stages, with high-boiling point components condensing at higher temperatures and low-boiling point components evaporating at lower temperatures, which can optimize the refrigeration performance of the entire system and widen the refrigeration temperature range.

[0037] The first refrigeration circuit is connected between the condenser evaporator 25 and the condenser separator 27. The first refrigeration circuit is set to handle the high-boiling point components in the multi-component mixed working medium. In this circuit, the refrigerant releases heat (condenses) in the condenser evaporator 25, and then flows through the condenser separator 27, where the high-boiling point components are separated and ready to enter the next cycle. The first refrigeration circuit ensures the refrigeration efficiency of the system in a higher temperature range, and at the same time, through the action of the condenser separator 27, it ensures the effective utilization of different components and the stable operation of the system.

[0038] The second refrigeration circuit is connected between the second evaporator 48 and the condensation separator 27. The second refrigeration circuit mainly processes the low-boiling point components in the multi-component mixed working fluid. In this circuit, the refrigerant absorbs heat (evaporates) in the second evaporator 48, and then flows to the condensation separator 27, where the low-boiling point components are separated and recycled. The second refrigeration circuit is responsible for providing refrigeration capacity in a lower temperature range. Through the separation effect of the condensation separator 27, the effective evaporation of the low-boiling point components at low temperatures is ensured, thereby achieving refrigeration in a wider temperature range.

[0039] Reference Figure 1 According to a self-cascade semiconductor temperature control system with precooling provided by the present invention, the circulating liquid subsystem includes a first circulating branch and a second circulating branch, the first circulating branch is connected to the first evaporator 14, and the second circulating branch is connected to the second evaporator 48. The first circulating branch and the second circulating branch are connected in parallel through a first three-way valve and a second three-way valve, and are connected to a main device 49.

[0040] It is understandable that the first circulation branch is directly connected to the first evaporator 14 of the precooling subsystem, and its main function is to provide preliminary cooling for the circulating fluid in the precooling stage. The second circulation branch is connected to the second evaporator 48 of the self-cascading subsystem, which is responsible for further reducing the temperature of the circulating fluid to meet the refrigeration requirements of the lower temperature range. The second circulation branch enables the circulating fluid to achieve deeper cooling in the self-cascading subsystem, which is crucial to meet the ultra-low temperature requirements in the semiconductor wafer etching process.

[0041] The arrangement of the first three-way valve and the second three-way valve allows the first circulation branch and the second circulation branch to be connected in parallel in the system, so that the flow direction and flow rate of the circulating fluid can be flexibly controlled. The parallel configuration of the three-way valve provides a variety of operation modes, and the cooling path of the circulating fluid can be adjusted according to the actual temperature requirements of the main device 49, thereby optimizing the refrigeration performance and energy efficiency of the system.

[0042] The first circulation branch and the second circulation branch are connected to the main device 49 through the three-way valve, ensuring that the circulating fluid can effectively absorb heat from the main device 49, be cooled in the refrigeration subsystem, and then circulate again to the main device 49. The continuous flow of the circulating fluid between the main device 49 and the refrigeration system is achieved, and the constant temperature control of the main device 49 is maintained.

[0043] Reference Figure 1 According to a self-cascade semiconductor temperature control system with precooling provided by the present invention, the precooling subsystem includes a condenser 5, a first precooling circuit and a second precooling circuit. The condenser 5 is connected to the front end of the precooling compressor 1, the first precooling circuit is connected between the condenser 5 and the first evaporator 14 and the precooling compressor 1, and the second precooling circuit is connected between the condenser evaporator 25 and the condenser 5.

[0044] It is understandable that the condenser 5 is located before the pre-cooling compressor 1. Its function is to make the refrigerant release heat before the compressor is compressed, so as to achieve the transformation of the gaseous refrigerant into a liquid state. The condenser 5 cools the refrigerant and condenses it, thereby improving the refrigeration efficiency of the system. At the same time, it also protects the compressor, preventing the compressor from inhaling superheated steam and extending its service life.

[0045] The first precooling circuit is connected between the condenser 5 and the first evaporator 14 and the precooling compressor 1. The first precooling circuit includes the condenser 5, the first evaporator 14 and the precooling compressor 1, forming a closed circulation path. The first precooling circuit is responsible for quickly reducing the temperature of the circulating fluid when the system is started, absorbing the heat of the circulating fluid through the first evaporator 14, then compressing it through the precooling compressor 1, and finally releasing the heat in the condenser 5 to complete a precooling cycle.

[0046] The second precooling circuit is connected between the condensing evaporator 25 and the condenser 5. The second precooling circuit connects the condensing evaporator 25 in the self-cascade subsystem and the condenser 5 in the precooling subsystem, forming an additional heat exchange path. The function of the second precooling circuit is to precool the self-cascade subsystem before the self-cascade subsystem is operated, to prevent the risk of a sudden increase in the load of the self-cascade compressor 21 in the self-cascade subsystem, and to avoid system downtime due to overpressure.

[0047] Reference Figure 1According to a self-cascade semiconductor temperature control system with precooling provided by the present invention, the precooling subsystem also includes a first cold spray branch, the first cold spray branch is connected to the rear end of the precooling compressor 1 and the front end of the condenser 5, and the first cold spray branch is provided with a first cold spray solenoid valve 8 and a cold spray thermal expansion valve 9. The rear end of the precooling compressor 1 is provided with a precooling exhaust temperature sensor 2. When the precooling exhaust temperature sensor 2 exceeds a set threshold, the first cold spray solenoid valve 8 is opened. At the same time, the opening of the cold spray thermal expansion valve 9 is controlled in real time according to the exhaust temperature measured by the precooling exhaust temperature sensor 2.

[0048] It can be understood that the first cold spray branch is connected to the rear end of the precooling compressor 1 and the front end of the condenser 5. The first cold spray branch is located between the precooling compressor 1 and the condenser 5. Its main function is to cool the high-temperature gas discharged from the compressor when necessary to protect the system and improve efficiency. By arranging the cold spray branch between the compressor and the condenser 5, the exhaust temperature of the compressor can be effectively controlled to prevent overheating, thereby protecting the compressor and ensuring the stable operation of the system.

[0049] The first cold spray solenoid valve 8 is located on the first cold spray branch, and is used to control the opening and closing of the cold spray branch. When the pre-cooling exhaust temperature sensor 2 detects that the exhaust temperature exceeds the set threshold, the first cold spray solenoid valve 8 will open, allowing part of the refrigerant to be cooled through the cold spray branch, thereby reducing the exhaust temperature.

[0050] The cold spray thermal expansion valve 9 is located on the first cold spray branch and is used to adjust the refrigerant flow through the cold spray branch. According to the exhaust temperature measured by the pre-cooling exhaust temperature sensor 2, the opening of the cold spray thermal expansion valve 9 is controlled in real time to accurately control the cooling amount. This ensures that the exhaust temperature remains within a suitable range, avoids overheating of the compressor, and optimizes the energy efficiency of the system.

[0051] The precooling exhaust temperature sensor 2 is located at the rear end of the precooling compressor 1. The precooling exhaust temperature sensor 2 is used to monitor the exhaust temperature of the compressor. When the exhaust temperature exceeds the set threshold, the sensor triggers the opening of the first cold spray solenoid valve 8 and provides exhaust temperature data to the cold spray thermal expansion valve 9 in real time to adjust its opening. In this way, the compressor exhaust temperature can be accurately controlled, the compressor can be protected, and the overall performance of the system can be improved.

[0052] Reference Figure 1 According to a self-cascade semiconductor temperature control system with precooling provided by the present invention, a first refrigeration electronic pulse valve and a first refrigeration thermal expansion valve 11 are provided on the first precooling circuit. The first refrigeration electronic pulse valve is used to allow the refrigerant to flow from the condenser 5 into the first evaporator 14. The first refrigeration thermal expansion valve 11 adjusts its own opening according to the superheat of the first evaporator 14 to adjust the real-time flow to the first evaporator 14.

[0053] It can be understood that the first refrigeration electronic pulse valve is on the first precooling circuit, and the first refrigeration electronic pulse valve is installed on the pipeline from the condenser 5 to the first evaporator 14. The main function of this valve is to control the flow of refrigerant from the condenser 5 to the first evaporator 14. By opening and closing, it can accurately allow the refrigerant to flow into the first evaporator 14, thereby starting the refrigeration cycle process. The fast response characteristics of the electronic pulse valve help to achieve precise flow control.

[0054] The first refrigeration thermal expansion valve 11 is located on the first precooling circuit. The first refrigeration thermal expansion valve 11 is usually located in front of the first evaporator 14 and is used to adjust the refrigerant flow entering the evaporator. According to the superheat of the first evaporator 14 (that is, the degree to which the refrigerant temperature at the outlet of the evaporator exceeds its saturated evaporation temperature), the thermal expansion valve automatically adjusts its opening to control the real-time flow to the first evaporator 14. This ensures that the evaporator works in the best state and avoids overheating or overcooling. By adjusting the flow, the thermal expansion valve helps to maintain the efficient operation of the evaporator and prevent the evaporator from reducing the refrigeration efficiency due to overheating or the refrigerant liquid hammer problem due to overcooling.

[0055] Reference Figure 1 According to a cascade semiconductor temperature control system with precooling provided by the present invention, the cascade subsystem also includes a second cold spray branch, the second cold spray branch is connected between the cascade compressor 21 and the condenser separator 27, a second cold spray solenoid valve 33 and a first capillary 34 are provided on the second cold spray branch, and a cascade exhaust temperature sensor 24 and a cascade exhaust pressure sensor 23 are provided between the cascade compressor 21 and the condenser evaporator 25; when the exhaust temperature monitored by the cascade exhaust temperature sensor 24 exceeds a preset value Tb, the second cold spray solenoid valve 33 is opened to throttle and cool down through the first capillary 34; when the exhaust temperature monitored by the cascade exhaust temperature sensor 24 is lower than the preset value Tb, it is closed after a delay of ns.

[0056] It can be understood that the second cold spray branch is connected between the self-cascade compressor 21 and the condenser separator 27. The second cold spray branch is located between the self-cascade compressor 21 and the condenser separator 27. Its function is to cool the high-temperature gas discharged from the compressor when necessary to protect the compressor and improve system efficiency. By arranging the cold spray branch between the compressor and the condenser separator 27, the exhaust temperature of the compressor can be effectively controlled to prevent overheating and ensure the stable operation of the system.

[0057] The second cold spray solenoid valve 33 is located on the second cold spray branch, and is used to control the opening and closing of the cold spray branch. When the self-cascade exhaust temperature sensor 24 detects that the exhaust temperature exceeds the preset value Tb, the second cold spray solenoid valve 33 opens, allowing the refrigerant to throttle and cool through the first capillary tube 34, thereby reducing the exhaust temperature and protecting the compressor.

[0058] The first capillary tube 34 is located on the second cold spray branch and is used to achieve throttling and cooling. When the second cold spray solenoid valve 33 is opened, the refrigerant is throttled through the first capillary tube 34, which causes the temperature and pressure of the refrigerant to decrease, thereby achieving a cooling effect.

[0059] The cascade exhaust temperature sensor 24 is located between the cascade compressor 21 and the condenser evaporator 25. The cascade exhaust temperature sensor 24 is used to monitor the exhaust temperature of the compressor. It monitors the exhaust temperature in real time and triggers the opening of the second cold spray solenoid valve 33 when the exhaust temperature exceeds the preset value Tb (settable) to reduce the temperature. When the exhaust temperature is lower than the preset value Tb (settable), the system will delay closing the second cold spray solenoid valve 33 for n (settable) seconds to avoid unnecessary energy consumption and system oscillation.

[0060] The cascade exhaust pressure sensor 23 is located between the cascade compressor 21 and the condenser evaporator 25. The cascade exhaust pressure sensor 23 is used to monitor the exhaust pressure of the compressor and provide exhaust pressure data for further optimizing the control and protection functions of the system.

[0061] Reference Figure 1 According to the present invention, a self-cascade semiconductor temperature control system with precooling is provided, the self-cascade also includes a gas storage branch, the gas storage branch is connected between the self-cascade compressor 21 and the condenser separator 27, and a gas storage tank 38, an exhaust valve 35 and an intake valve 37 are arranged on the gas storage branch, the intake valve 37 is connected between the gas storage tank 38 and the condenser evaporator 25, the exhaust valve 35 is connected between the gas storage tank 38 and the self-cascade compressor 21, and a self-cascade exhaust pressure sensor 23 is also arranged between the self-cascade compressor 21 and the condenser evaporator 25, and a liquid supply temperature sensor 46 is arranged on the circulating liquid subsystem; in the process of throttling and cooling through the first capillary tube, when the exhaust pressure monitored by the self-cascade exhaust pressure sensor 23 exceeds the set value Pv1, the intake valve 37 is opened for pressure relief; when the exhaust pressure monitored by the self-cascade exhaust pressure sensor 23 is lower than the set value Pv1, the intake valve 37 is closed; when the real-time value monitored by the liquid supply temperature sensor 46 drops below -40°C, the exhaust valve 35 is opened.

[0062] It is understood that the gas storage branch is connected between the self-cascade compressor 21 and the condenser 27. The role of the gas storage branch is to provide an additional pressure management and regulation mechanism to optimize the performance and reliability of the system. The gas storage branch balances the pressure fluctuations in the system through the gas storage tank 38, prevents the compressor from being damaged due to excessive pressure, and maintains the stable operation of the system.

[0063] The gas storage tank 38 is located on the gas storage branch and is used to store a certain amount of refrigerant gas as a pressure buffer. The gas storage tank 38 can absorb the pressure peak in the system, reduce pressure fluctuations, and protect the compressor from the influence of excessive pressure.

[0064] The air inlet valve 37 is connected between the gas storage tank 38 and the condenser evaporator 25, and is used to control the flow of the refrigerant gas into the gas storage tank 38. When the self-cascade exhaust pressure sensor 23 detects that the exhaust pressure exceeds the set value Pv1, the air inlet valve 37 opens to allow the refrigerant gas to enter the gas storage tank 38, thereby reducing the pressure of the system and avoiding overpressure.

[0065] The exhaust valve 35 is connected between the gas storage tank 38 and the cascade compressor 21. The exhaust valve 35 is used to release the gas in the gas storage tank 38 to adjust the system pressure. When the liquid supply temperature sensor 46 detects that the temperature of the circulating liquid drops below -40°C (settable), the exhaust valve 35 opens to release the gas in the gas storage tank 38 to prevent the system from being over-pressured. The system is protected by releasing the low-boiling-point components in the mixed working fluid to reduce the pressure.

[0066] The cascade exhaust pressure sensor 23 is located between the cascade compressor 21 and the condenser evaporator 25. The cascade exhaust pressure sensor 23 is used to monitor the exhaust pressure of the compressor. It monitors the exhaust pressure in real time and triggers the opening of the intake valve 37 when the pressure exceeds the set value Pv1, and closes the intake valve 37 after the pressure drops, so as to maintain the system pressure within a safe range.

[0067] The liquid supply temperature sensor 46 is located on the circulating liquid subsystem and is used to monitor the temperature of the circulating liquid. It monitors the temperature of the circulating liquid in real time and triggers the opening of the exhaust valve 35 when the temperature drops below -40°C to prevent the system from being over-pressured and ensure the safe operation of the system.

[0068] Reference Figure 1 According to a self-cascade semiconductor temperature control system with pre-cooling provided by the present invention, the second refrigeration circuit is provided with a third refrigeration electronic pulse valve 29 and a capillary branch connected to both ends of the third refrigeration electronic pulse valve 29, and a second capillary tube 31 is provided on the capillary branch; when the real-time value monitored by the liquid supply temperature sensor 46 is lower than -80°C, the third refrigeration electronic pulse valve 29 is closed, and throttling refrigeration is performed through the capillary branch.

[0069] It is understandable that the third refrigeration electronic pulse valve 29 is located on the second refrigeration circuit, and the third refrigeration electronic pulse valve 29 is used to control the flow of the refrigerant in the second refrigeration circuit. The valve can be quickly opened or closed according to the needs of the system, accurately controlling the flow of the refrigerant, thereby adjusting the cooling capacity.

[0070] The capillary branch is connected to both ends of the third refrigeration electronic pulse valve 29. The capillary branch is a small bypass pipe connected to one side of the main refrigeration circuit for specific flow control. The capillary branch provides an additional control path, so that the refrigeration capacity can be adjusted by throttling under specific conditions.

[0071] The second capillary tube 31 is located on the capillary branch. The second capillary tube 31 is a small pipe used to achieve a throttling effect, that is, to increase the flow rate of the refrigerant by reducing the cross section of the pipe, thereby reducing its pressure and temperature. When the supply temperature sensor 46 detects that the real-time temperature is lower than -80°C, the second capillary tube 31 reduces the temperature of the refrigerant through throttling, while reducing the cooling capacity to prevent the circulating liquid from being overcooled.

[0072] In a specific embodiment, the precooling subsystem includes a precooling compressor 1, a precooling exhaust temperature sensor 2, a precooling oil separator 3, a first one-way valve 4, a condenser 5, a condensing pressure regulating valve 6, a precooling drying filter 7, a first cold spray solenoid valve 8, a cold spray thermal expansion valve 9, a first refrigeration electric pulse valve 10, a first refrigeration thermal expansion valve 11, a second refrigeration electronic pulse valve 12, a second refrigeration thermal electric expansion valve 13, a first evaporator 14, a second one-way valve 15, a precooling hot gas electronic expansion valve 16 and an intake pressure sensor 17.

[0073] The cascade subsystem includes a cascade compressor 21, a cascade oil separator 22, a cascade exhaust pressure sensor 23, a cascade exhaust temperature sensor 24, a condenser evaporator 25, a cascade dry filter 26, a condenser separator 27, a regenerator 28, a third refrigeration electronic pulse valve 29, a fourth capillary 30, a second capillary 31, a third capillary 32, a second cold spray solenoid valve 33, a first capillary 34, an exhaust valve 35, a third one-way valve 36, an air intake valve 37, an air storage tank 38 and a cascade hot air electronic expansion valve 39, The circulating liquid subsystem includes a flow meter 40 , a first three-way valve, a second three-way valve, a circulating pump 43 , a heater 44 , a water tank 45 , a liquid supply temperature sensor 46 , a liquid supply pressure sensor 47 , a second evaporator 48 , a main device 49 and a return temperature sensor 50 .

[0074] When the temperature control device receives the instruction from the main device 49 and SV≥-40℃, only the precooling subsystem operates; at this time, the precooling compressor 1 starts, the second refrigeration electronic pulse valve 12 opens, and the second refrigeration thermoelectric expansion valve 13 is controlled in real time according to the superheat of the first evaporator 14 to prevent the system from returning liquid. The preset opening of the second refrigeration electronic pulse valve 12 is A%, the preset no-load suction pressure value is P1, the maximum load suction pressure value is P2, the pulse period is T, and the opening time Ta=A%×T. When the pressure is low, the precooling hot gas electronic expansion valve 16 performs correction adjustment of the preset pressure value P1 to meet the stability of the system pressure. In order to meet the operating conditions of both load and no-load, the valve opening correction coefficient X is set. When the main equipment 49 is running without load, the return temperature sensor 50 monitoring value T1 is approximately equal to the liquid supply temperature sensor 46 monitoring value T2. When the main equipment 49 is running with load, T1 and T2 produce a difference ΔT. When ΔT = 0, the correction coefficient is 1 (according to the actual debugging setting of the equipment). When ΔT is the maximum load, the correction coefficient is 0.5 (according to the actual debugging setting of the equipment), that is: A%*1 at maximum load, A%*0.5 at no-load operation. When between the two intervals, the correction coefficient is in the linear correspondence principle within the interval of P1 and P2.

[0075] When the temperature control device receives the instruction from the main device 49, -140℃≤SV<-40℃, the temperature control device determines that the dual system is running; at this time, the precooling subsystem is started first, the precooling compressor 1 is started, the first refrigeration electric pulse valve 10 is opened, and the first refrigeration thermal expansion valve 11 is controlled in real time according to the superheat of the first evaporator 14 to prevent the system from returning liquid. The preset opening of the first refrigeration electric pulse valve 10 is B%, the preset suction pressure value is P3, and the precooling hot gas electronic expansion valve 16 performs correction adjustment of the preset pressure value P3 to meet the stable operation of the precooling subsystem. When the exhaust pressure sensor of the cascade system monitors the pressure value Pz<11bar (settable), the cascade compressor 21 is operated to avoid the startup overpressure of the cascade system and improve the stability of the system. The system is running without load or with load, and the control logic of the cascade hot gas electronic expansion valve 39 and the third refrigeration electronic pulse valve 29 refers to the control logic of the corresponding valve of the precooling subsystem, and the preset opening and correction coefficient are set according to the system. Below -80℃, the refrigeration margin of the cascade system is relatively small, and correction adjustment is performed by the circulating fluid system heater 44.

[0076] When SV≥-40℃, the precooling compressor 1 is started with a delay of 10s (settable), the circulating liquid pump is turned on, and the A-B of the first three-way valve and the second three-way valve are connected; when SV<-40℃, the cascade compressor 21 is started with a delay of 10s (settable), the circulating liquid pump is turned on, and the A-C of the first three-way valve and the second three-way valve are connected. According to the set flow and pressure, the inverter is adjusted to meet the flow and pressure requirements of the main equipment 49. Avoid high-temperature shutdown caused by the temperature rise caused by the heat dissipation of the water pump before the cascade compressor 21 is started.

[0077] When the exhaust temperature monitored by the pre-cooling exhaust temperature sensor 2 exceeds Ta, the first cold spray solenoid valve 8 is opened, and the cold spray thermal expansion valve 9 is adjusted in real time according to the suction temperature to avoid compressor failure caused by liquid spray.

[0078] When the exhaust temperature monitored by the cascade exhaust temperature sensor 24 exceeds Tb, the second cold spray solenoid valve 33 opens and throttles and cools down through the first capillary 34. After it is lower than Tb, it closes after a delay of 5s (settable); during the cooling process, when the exhaust pressure monitored by the cascade exhaust pressure sensor 23 exceeds the set value Pv, the intake valve 37 opens to release the pressure, and closes when it is lower than Pv1. When the real-time value monitored by the liquid supply temperature sensor 46 drops below -40°C, the exhaust valve 35 opens to avoid overpressure shutdown caused by a large amount of multi-mixed working fluid entering the system. When the real-time value monitored by the liquid supply temperature sensor 46 is lower than -80°C, the third refrigeration electronic pulse valve 29 closes. Only the second capillary 31 is used for throttling refrigeration. The condensation separator 27 is used to separate the multi-component mixed working medium. The high boiling point component in the mixed working medium is throttled through the third capillary 32, evaporated in the regenerator 28, and the lower boiling point component is condensed into liquid, and then throttled and cooled through the third refrigeration electronic pulse valve 29, the fourth capillary 30, and the second capillary 31. This is a reciprocating cycle. The third one-way valve 36 is used for overpressure unloading after the system is abnormally shut down.

[0079] On the other hand, the present invention further provides a control method for a self-cascade semiconductor temperature control system with precooling, which is applied to the self-cascade semiconductor temperature control system with precooling as described above, and the control method comprises: The temperature control device PLC receives the instruction from the main device 49 and determines the temperature threshold preset by the main device 49; When the temperature threshold preset by the main device 49 is: SV ≥ -40°C, it is determined that only the pre-cooling subsystem is running; When the preset temperature threshold of the main device 49 is: -140℃≤SV<-40℃, it is determined that the precooling subsystem and the auto-cascade subsystem are running simultaneously, wherein the precooling compressor 1 is started first, and when the reading of the exhaust pressure sensor reaches the preset value, the auto-cascade compressor 21 is started.

[0080] It can be understood that the programmable logic controller (PLC) is the core control unit of the temperature control system, which receives temperature control instructions from the main equipment 49 (such as semiconductor manufacturing equipment).

[0081] The PLC first communicates with the master device 49 to obtain the required temperature set value (SV).

[0082] Based on the temperature thresholds set by the master device 49, the PLC can decide which subsystems need to be operated and how to adjust these subsystems to achieve the desired temperature control.

[0083] The PLC compares the received temperature setpoint with the preset temperature threshold to determine the operating mode.

[0084] When the preset temperature threshold of the main device 49 is: SV ≥ -40°C, if the required temperature of the main device 49 is -40°C or above, the requirement can be met by simply running the pre-cooling subsystem.

[0085] The PLC controls the pre-cooling subsystem to run independently and shuts down the self-folding subsystem to save energy and improve efficiency.

[0086] When the preset temperature threshold of the main device 49 is: -140°C ≤ SV < -40°C, when the temperature required by the main device 49 is lower than -40°C but higher than -140°C, the precooling subsystem and the self-cascading subsystem need to run simultaneously to achieve a lower temperature.

[0087] The PLC first starts the precooling compressor 1 to start the precooling process.

[0088] When the reading of the exhaust pressure sensor reaches a preset value, indicating that the precooling subsystem has reached a certain pressure level, the PLC starts the auto-cascade compressor 21.

[0089] This ensures a smooth transition of the system to a low temperature state while avoiding damage to the compressor due to pressure imbalance.

[0090] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A self-cascaded semiconductor temperature control system with precooling, characterized in that: include: A circulating liquid subsystem, the circulating liquid subsystem is connected to the main equipment, and the circulating liquid subsystem is used to provide the main equipment with circulating liquid after cooling; A precooling subsystem, the precooling subsystem comprising a first evaporator and a precooling compressor, the first evaporator and the precooling compressor are connected, and the precooling subsystem is connected to the circulating liquid subsystem through the first evaporator; The self-cascade subsystem includes a self-cascade compressor, a second evaporator and a condensing evaporator. The self-cascade compressor is connected to the condensing evaporator and the second evaporator. The self-cascade subsystem is connected to the circulating liquid subsystem through the second evaporator. The self-cascade subsystem is connected to the precooling subsystem through the condensing evaporator.

2. The self-cascaded semiconductor temperature control system with precooling according to claim 1, characterized in that: The self-cascading subsystem includes a condenser and a first refrigeration circuit and a second refrigeration circuit. The first refrigeration circuit is connected between the condenser evaporator and the condenser, and the second refrigeration circuit is connected between the second evaporator and the condenser.

3. The self-cascaded semiconductor temperature control system with precooling according to claim 1, characterized in that: The circulating liquid subsystem includes a first circulating branch and a second circulating branch, the first circulating branch is connected to the first evaporator, the second circulating branch is connected to the second evaporator, the first circulating branch and the second circulating branch are connected in parallel through a first three-way valve and a second three-way valve, and are connected to the main equipment.

4. The self-cascaded semiconductor temperature control system with precooling according to claim 1, characterized in that: The precooling subsystem includes a condenser, a first precooling circuit and a second precooling circuit. The condenser is connected to the front end of the precooling compressor. The first precooling circuit is connected between the condenser and the first evaporator and the precooling compressor. The second precooling circuit is connected between the condenser evaporator and the condenser.

5. The self-cascaded semiconductor temperature control system with precooling according to claim 4, characterized in that: The precooling subsystem also includes a first cold spray branch, which is connected to the rear end of the precooling compressor and the front end of the condenser. The first cold spray branch is provided with a first cold spray solenoid valve and a cold spray thermal expansion valve. The rear end of the precooling compressor is provided with a precooling exhaust temperature sensor. When the precooling exhaust temperature sensor exceeds a set threshold, the first cold spray solenoid valve is opened. At the same time, the opening of the cold spray thermal expansion valve is controlled in real time according to the exhaust temperature measured by the precooling exhaust temperature sensor.

6. The self-cascaded semiconductor temperature control system with precooling according to claim 5, characterized in that: The first pre-cooling circuit is provided with a first refrigeration electronic pulse valve and a first refrigeration thermal expansion valve. The first refrigeration electronic pulse valve is used to allow refrigerant to flow from the condenser into the first evaporator. The first refrigeration thermal expansion valve adjusts its opening according to the superheat of the first evaporator to adjust the real-time flow to the first evaporator.

7. The self-cascaded semiconductor temperature control system with precooling according to claim 2, characterized in that: The self-cascade subsystem further includes a second cold spray branch, which is connected between the self-cascade compressor and the condenser separator, and is provided with a second cold spray solenoid valve and a first capillary tube, and a self-cascade exhaust temperature sensor and a self-cascade exhaust pressure sensor are provided between the self-cascade compressor and the condenser evaporator; When the exhaust temperature monitored by the self-cascade exhaust temperature sensor exceeds a preset value Tb, the second cold spray solenoid valve is opened to throttle and cool the exhaust gas through the first capillary tube; When the exhaust temperature monitored by the self-cascaded exhaust temperature sensor is lower than the preset value Tb, it is closed after a delay of ns.

8. The self-cascaded semiconductor temperature control system with precooling according to claim 7, characterized in that: The self-cascade further comprises an air storage branch, which is connected between the self-cascade compressor and the condenser separator, and is provided with an air storage tank, an exhaust valve and an air intake valve on the air storage branch, the air intake valve is connected between the air storage tank and the condenser evaporator, the exhaust valve is connected between the air storage tank and the self-cascade compressor, and an auto-cascade exhaust pressure sensor is also provided between the self-cascade compressor and the condenser evaporator, and a liquid supply temperature sensor is provided on the circulating liquid subsystem; During the process of throttling and cooling through the first capillary tube, when the exhaust pressure monitored by the self-cascaded exhaust pressure sensor exceeds the set value Pv1, the intake valve opens to release pressure; When the exhaust pressure monitored by the self-cascaded exhaust pressure sensor is lower than the set value Pv1, the intake valve is closed; When the real-time value monitored by the liquid supply temperature sensor drops below -40°C, the exhaust valve opens.

9. The self-cascaded semiconductor temperature control system with precooling according to claim 8, characterized in that: The second refrigeration circuit is provided with a third refrigeration electronic pulse valve and a capillary branch connected to both ends of the third refrigeration electronic pulse valve, and the capillary branch is provided with a second capillary tube; When the real-time value monitored by the liquid supply temperature sensor is lower than -80°C, the third refrigeration electronic pulse valve is closed, and throttling refrigeration is performed through the capillary branch.

10. A control method for a self-cascade semiconductor temperature control system with precooling, applied to the self-cascade semiconductor temperature control system with precooling as claimed in any one of claims 1 to 9, characterized in that: The control method comprises: The temperature control device PLC receives the instructions from the main device and determines the temperature threshold preset by the main device; When the temperature threshold preset by the main device is: SV ≥ -40°C, it is determined that only the pre-cooling subsystem is running; When the preset temperature threshold of the main device is: -140℃≤SV<-40℃, it is determined that the precooling subsystem and the cascade subsystem are running simultaneously, wherein the precooling compressor is started first, and when the reading of the exhaust pressure sensor reaches the preset value, the cascade compressor is started.

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