A temperature control device and a temperature control method

Abstract

The application provides a temperature control device and a temperature control method, and relates to the technical field of semiconductor processing. The temperature control device comprises a cooling liquid circulation system and a refrigerant circulation system. The refrigerant circulation system can selectively construct a first refrigerant circulation loop and a second refrigerant circulation loop according to the liquid supply temperature requirement, so that the first compressor and the second compressor are cooperatively operated to realize two-stage compression; or a third refrigerant circulation loop or a fourth refrigerant circulation loop is constructed, and only one compressor is started to perform single-stage compression. It can be seen that the temperature control device provided by the application can flexibly adjust the compressor configuration according to the actual cooling capacity requirement, so that the load end can quickly and stably reach the target temperature, the excess refrigerating capacity and energy waste are avoided, and efficient and energy-saving operation is realized.

Description

Technical Field

[0001] This invention relates to the field of semiconductor processing technology, and more specifically, to a temperature control device and a temperature control method. Background Technology

[0002] Semiconductor temperature control equipment is a crucial component in semiconductor manufacturing, requiring high precision in temperature control. During chip production, a stable supply of coolant must be provided to the load. However, the required coolant temperature varies depending on the specific chip processing step, and the load conditions also fluctuate significantly. Therefore, the temperature control equipment must respond rapidly to load variations, switching temperatures quickly and maintaining a stable supply coolant temperature.

[0003] However, the inventors discovered that current temperature control devices suffer from large temperature fluctuations and slow response times when the load conditions change. Furthermore, current temperature control devices do not consider energy consumption, resulting in generally high energy consumption. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a temperature control device and a temperature control method that can respond quickly and meet the device's usage requirements with minimal energy consumption.

[0005] Specifically, the present invention provides a temperature control device, including a coolant circulation system and a refrigerant circulation system, wherein the refrigerant circulation system is capable of forming at least one of a first refrigerant circulation loop, a second refrigerant circulation loop, a third refrigerant circulation loop and a fourth refrigerant circulation loop;

[0006] The first refrigerant circulation loop includes a second branch consisting of a first compressor, a first heat exchange element, a first electronic expansion valve, and a second heat exchange element connected in series.

[0007] The second refrigerant circulation loop includes a first compressor, a first heat exchange element, a first branch of a second heat exchange element, a second electronic expansion valve, a first branch of a third heat exchange element, a second compressor, and a third branch of the second heat exchange element connected in series.

[0008] The third refrigerant circulation loop includes a first compressor, a first heat exchange element, a first branch of a second heat exchange element, a second electronic expansion valve, and a first branch of a third heat exchange element connected in series.

[0009] The fourth refrigerant circulation loop includes a second compressor, a first heat exchange element, a first branch of the second heat exchange element, a second electronic expansion valve, and a first branch of the third heat exchange element, which are connected in series.

[0010] The beneficial effects of the temperature control device and method provided in the embodiments of the present invention include:

[0011] This temperature control device can selectively construct a first refrigerant circulation loop and a second refrigerant circulation loop according to the required refrigerant supply temperature, enabling the first and second compressors to operate collaboratively for two-stage compression; or it can construct a third or fourth refrigerant circulation loop, using only one compressor for single-stage compression. Therefore, the temperature control device provided by this invention can flexibly adjust the compressor configuration according to actual cooling demand, ensuring that the load side quickly and stably reaches the target temperature while avoiding excessive cooling capacity and energy waste, thus achieving highly efficient and energy-saving operation. Attached Figure Description

[0012] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0013] Figure 1 This is a schematic diagram of the temperature control device provided in this embodiment;

[0014] Figure 2 This is a schematic diagram of the structure of the first refrigerant circulation loop of the temperature control device provided in this embodiment;

[0015] Figure 3 This is a schematic diagram of the second refrigerant circulation loop of the temperature control device provided in this embodiment;

[0016] Figure 4 This is a schematic diagram of the third refrigerant circulation loop of the temperature control device provided in this embodiment;

[0017] Figure 5 This is a schematic diagram of the fourth refrigerant circulation loop of the temperature control device provided in this embodiment;

[0018] Figure 6 This is a schematic diagram of the coolant circulation system of the temperature control device provided in this embodiment;

[0019] Figure 7 This is a schematic diagram of the logic flow of the temperature control method provided in this embodiment;

[0020] Figure 8 The logic flowchart of the temperature control device provided in this embodiment when it is in two-stage compression refrigeration mode;

[0021] Figure 9This is a logic flowchart of the temperature control device in the second sub-mode when the second compressor is running alone, as provided in this embodiment.

[0022] Figure 10 The logic flowchart for the temperature control device provided in this embodiment when it is in the first sub-mode where the first compressor is running alone.

[0023] Icons: 010 - Temperature control equipment; 100 - Refrigerant circulation system; 300 - Coolant circulation system; 1 - First compressor; 2 - First check valve; 3 - Fourth temperature sensor; 4 - Fourth pressure sensor; 5 - First heat exchange element; 6 - Fifth temperature sensor; 7 - Receiver; 8 - First electronic expansion valve; 9 - Second heat exchange element; 10 - Second electronic expansion valve; 11 - Third heat exchange element; 12 - Second three-way valve; 13 - Second temperature sensor; 14 - Second pressure sensor; 15 - Second compressor; 16 - First three-way valve; 17 - Second check valve; 18 - First temperature sensor; 19 - First pressure sensor; 20 - Water tank; 21 - Circulation pump; 22 - Electric heating element; 23 - Third temperature sensor; 24 - Load. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0025] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0026] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0027] In the description of this invention, it should be noted that if terms such as "upper," "lower," "inner," or "outer" are used to indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of this invention is usually placed, they are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0028] Furthermore, the terms "first" and "second" are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0029] It should be noted that, where there is no conflict, the features in the embodiments of the present invention can be combined with each other.

[0030] The following describes in detail the overall structure, working principle, and technical effects of the temperature control device provided by the present invention, as well as the detailed steps, implementation principles, and technical effects of the supporting temperature control method, through embodiments and in conjunction with the accompanying drawings.

[0031] Please see Figure 1 This invention provides a temperature control device 010, applied in the field of semiconductor processing technology, capable of rapidly responding to and meeting the usage requirements of equipment with minimal energy consumption. The temperature control device 010 includes a coolant circulation system 300 and a refrigerant circulation system 100.

[0032] The refrigerant circulation system 100 includes a first compressor 1, a second compressor 15, a first electronic expansion valve 8, a second electronic expansion valve 10, a first heat exchange element 5, a second heat exchange element 9, and a third heat exchange element 11 in a first branch. Furthermore, the refrigerant circulation system 100 can selectively form at least one of a first refrigerant circulation loop, a second refrigerant circulation loop, a third refrigerant circulation loop, and a fourth refrigerant circulation loop to adapt to various operating conditions.

[0033] Specifically, please refer to Figure 2 , Figure 2 The thick line in the diagram represents the first refrigerant circulation loop, which includes a second branch consisting of a first compressor 1, a first heat exchange element 5, a first electronic expansion valve 8, and a second heat exchange element 9 connected in series.

[0034] Please see Figure 3 , Figure 3 The thick line in the diagram represents the second refrigerant circulation loop, which includes a first compressor 1, a first heat exchange element 5, a first branch of a second heat exchange element 9, a second electronic expansion valve 10, a first branch of a third heat exchange element 11, a second compressor 15, and a third branch of the second heat exchange element 9, all connected in series.

[0035] Please see Figure 4 , Figure 4 The thick line in the diagram represents the third refrigerant circulation loop, which includes the first branch of the first compressor 1, the first heat exchange element 5, the second heat exchange element 9, the second electronic expansion valve 10, and the first branch of the third heat exchange element 11, which are connected in series.

[0036] Please see Figure 5 , Figure 5 The thick line in the diagram represents the fourth refrigerant circulation loop, which includes the second compressor 15, the first heat exchange element 5, the first branch of the second heat exchange element 9, the second electronic expansion valve 10, and the first branch of the third heat exchange element 11, which are connected in series.

[0037] Based on the above, the temperature control device 010 can selectively construct a first refrigerant circulation loop and a second refrigerant circulation loop according to the liquid supply temperature requirements, enabling the first compressor 1 and the second compressor 15 to operate collaboratively to achieve two-stage compression; or construct a third or fourth refrigerant circulation loop, using only one compressor for single-stage compression. Therefore, the temperature control device 010 provided by this invention can flexibly adjust the compressor configuration according to actual cooling demand, ensuring that the load 24 reaches the target temperature quickly and stably while avoiding excessive cooling capacity and energy waste, achieving efficient and energy-saving operation.

[0038] Please refer to it again. Figure 1 It should be noted that the second heat exchange element 9 has multiple interfaces, including port a, port b, port c, port d and port e, which form three independent but heat-exchangeable fluid channels inside.

[0039] In the first branch, after the refrigerant flows out from the first heat exchange element 5, it enters the second heat exchange element 9 through port a, flows through the internal channel and is discharged through port e, flowing to the second electronic expansion valve 10.

[0040] In the second branch, after the refrigerant flows out from the first electronic expansion valve 8, it enters the second heat exchange element 9 through port b, flows through the internal channel, and is discharged through port c, returning to the inlet end of the first compressor 1.

[0041] In the third branch, the high-temperature and high-pressure gaseous refrigerant from the outlet of the second compressor 15 enters the second heat exchange element 9 through port d, flows through the internal channel and is discharged through port c, and merges into the inlet of the first compressor 1.

[0042] It is understandable that port C is the common outlet of the second and third branches. When the second refrigerant circulation loop is running, the gaseous refrigerant from the two branches merges here and is then transported to the inlet of the first compressor 1 through the common pipeline.

[0043] Furthermore, the temperature control device 010 meets the temperature control requirements of the load 24 in the coolant circulation system 300 under different process conditions through heat exchange between the refrigerant in the refrigerant circulation system 100 and the coolant in the coolant circulation system 300.

[0044] Specifically, the coolant circulation system 300 includes a load 24, a second branch of a third heat exchange element 11, and a third temperature sensor 23 connected in series, forming a closed loop. The second branch of the third heat exchange element 11 is located at the outlet end of the load 24 and is used to receive the high-temperature coolant after absorbing heat from the load 24; the third temperature sensor 23 is located at the inlet end of the load 24 and is used to monitor the temperature of the coolant entering the load 24 in real time.

[0045] like Figure 6 As shown in the figure, the thick line represents the actual flow path of the coolant circulation loop. After absorbing the heat generated by the load 24, the coolant enters the second branch of the third heat exchange element 11 from its outlet end, where it exchanges heat with the low-temperature refrigerant in the first branch, releasing heat and being cooled down; then it flows through the third temperature sensor 23 to complete temperature detection, and returns to the inlet end of the load 24, completing one closed-loop cycle.

[0046] Similar to the second heat exchange element 9 and the third heat exchange element 11, the first heat exchange element 5 also includes a first branch and a second branch that are independent of each other but capable of heat exchange. The first branch is connected to the refrigerant circulation system 100 for refrigerant circulation; the second branch is connected to the process cooling water system (PCW) to achieve circulating heat exchange of cooling water.

[0047] During operation, the high-temperature and high-pressure gaseous refrigerant in the first heat exchange element 5 condenses and releases heat in the first branch, and exchanges heat with the process cooling water in the second branch, transforming into a high-pressure and medium-temperature liquid refrigerant; at the same time, the process cooling water absorbs the waste heat released by the refrigerant, and its temperature rises, realizing the recovery and reuse of heat energy.

[0048] Please refer to it again. Figure 1 In the embodiments provided by the present invention, the refrigerant circulation system 100 further includes a first three-way valve 16 and a second three-way valve 12, which are used to switch the flow path of the refrigerant under different operating conditions, thereby enabling the refrigerant circulation system 100 to selectively form at least one of a first refrigerant circulation loop, a second refrigerant circulation loop, a third refrigerant circulation loop and a fourth refrigerant circulation loop.

[0049] Specifically, the first three-way valve 16 includes port a, port b, and port c. Port a of the first three-way valve 16 is connected to the outlet end of the second compressor 15 and is used to receive the high-temperature and high-pressure gaseous refrigerant discharged by the second compressor 15; port b is connected to the inlet end of the third branch of the second heat exchange element 9, so that the exhaust gas from the second compressor 15 can enter the interior of the second heat exchange element 9 and be cooled by heat exchange with the refrigerant in other branches; port c is connected to the outlet end of the first compressor 1, forming a bypass return path, allowing the refrigerant discharged by the second compressor 15 to directly enter the first heat exchange element 5.

[0050] Accordingly, the second three-way valve 12 includes port a, port b, and port c. Port a of the second three-way valve 12 is connected to the outlet end of the first branch of the third heat exchange element 11 and is used to receive the gaseous refrigerant after evaporation in the third heat exchange element 11; port b is connected to the inlet end of the second compressor 15 and serves as the intake passage of the second compressor 15, allowing the refrigerant to enter the second compressor 15 through this path; port c is connected to the inlet end of the first compressor 1 and constitutes the suction return path of the first compressor 1.

[0051] Furthermore, it should be noted that in other embodiments of the present invention, the implementation of the first three-way valve 16 and the second three-way valve 12 is not limited to a specific type of valve structure. For example, they can be replaced by valves with flow path switching functions, such as electromagnetic three-way valves, electric multi-way switching valves, or reversing valves (e.g., four-way reversing valves). As long as the on / off control and direction switching of the refrigerant flow path can be achieved, ensuring the construction of corresponding refrigerant circulation loops under different operating conditions, they all fall within the protection scope of the present invention.

[0052] Furthermore, when the coolant circulation system 300 is operating under low-temperature supply conditions, in order to meet the cryogenic temperature requirements (e.g., -45℃ to -25℃) of the load 24, the refrigerant circulation system 100 switches to a two-stage compression operation mode. Specifically, the first electronic expansion valve 8 is turned on, allowing the refrigerant to pass smoothly and enter the second branch of the second heat exchange element 9; at the same time, ports a and b of the second three-way valve 12 are turned on, allowing the low-temperature, low-pressure gaseous refrigerant from the first branch of the third heat exchange element 11 to flow into the inlet of the second compressor 15 after passing through the second three-way valve 12; ports a and b of the first three-way valve 16 are turned on, directing the exhaust gas of the second compressor 15 to the third branch of the second heat exchange element 9;

[0053] In this configuration, the refrigerant circulation system 100 can simultaneously form a first refrigerant circulation loop and a second refrigerant circulation loop.

[0054] In the first refrigerant cycle loop, such as Figure 2As shown, the high-temperature and high-pressure refrigerant gas discharged from the first compressor 1 enters the first heat exchange element 5, and after condensation and heat release, it becomes a high-pressure medium-temperature liquid (e.g., 25°C). Then, it passes through the first electronic expansion valve 8 for throttling and pressure reduction, and is converted into a medium-pressure low-temperature liquid refrigerant (e.g., 0°C), and enters the second branch of the second heat exchange element 9.

[0055] In the second refrigerant cycle loop, such as Figure 3 As shown, a portion of the high-pressure, medium-temperature liquid refrigerant (e.g., 25°C) from the first heat exchange element 5 is diverted to the first branch of the second heat exchange element 9. At this time, the first and second branches of the second heat exchange element 9 exchange heat internally: the medium-pressure, low-temperature liquid refrigerant in the second branch absorbs heat and evaporates, transforming into a medium-pressure, low-temperature gaseous refrigerant, and returns to the first compressor 1, thus completing the first refrigerant circulation loop. Meanwhile, the high-pressure, medium-temperature liquid refrigerant in the first branch cools down due to heat release, becoming a medium-pressure, low-temperature liquid (e.g., 0°C), and then enters the second electronic expansion valve 10, where it is further throttled into an ultra-low temperature, ultra-low pressure liquid refrigerant, before flowing into the first branch of the third heat exchange element 11.

[0056] In the third heat exchange element 11, the cryogenic refrigerant in the first branch exchanges heat with the coolant in the second branch: the refrigerant absorbs heat and evaporates into a cryogenic, cryogenic, and cryogenic gaseous state, returning to the second compressor 15; at the same time, the coolant releases heat and its temperature decreases, thus achieving effective heat exchange between the refrigerant circulation system 100 and the coolant circulation system 300.

[0057] Subsequently, with the second three-way valve 12 in the ab-open state, the low-temperature, low-pressure gaseous refrigerant flowing from the third heat exchange element 11 enters the second compressor 15 and is compressed into a high-temperature, high-pressure gaseous refrigerant. Then, with the first three-way valve 16 in the ab-open state, this gaseous refrigerant flows into the third branch of the second heat exchange element 9, where it exchanges heat with the refrigerant in the second branch, cooling it into a medium-temperature, medium-pressure gas, and finally enters the first compressor 1, completing the closed loop of the second refrigerant circulation circuit.

[0058] It should be noted that under this operating condition, the second compressor 15 performs the first stage of compression, increasing the pressure and temperature of the low-temperature, low-pressure gaseous refrigerant from the third heat exchange element 11, thus creating conditions for further compression. The first compressor 1 and the second compressor 15 work together to form a series two-stage compression structure. By completing the compression process in stages, the total compression ratio is effectively distributed, avoiding technical problems such as reduced energy efficiency, excessively high exhaust temperature, or inability to achieve low-temperature refrigeration caused by an excessively high single-stage compression ratio. This ensures that the system operates efficiently and stably under low-temperature conditions.

[0059] Furthermore, when the coolant circulation system 300 is operating at a medium-to-high temperature supply (e.g., the required temperature at load 24 is -20°C to 80°C), it can switch to either the first compressor 1 or the second compressor 15 for single-stage compression based on the cooling capacity requirements. In one embodiment, ports a and c of the second three-way valve 12 are connected, enabling the refrigerant circulation system 100 to form a third refrigerant circulation loop. In another embodiment, ports a and c of the first three-way valve 16 are connected, and ports a and b of the second three-way valve 12 are connected, enabling the refrigerant circulation system 100 to form a fourth refrigerant circulation loop.

[0060] like Figure 4 As shown, the high-temperature and high-pressure refrigerant gas discharged from the first compressor 1 enters the first heat exchange element 5, and after condensation and heat release, it is converted into a high-pressure and medium-temperature liquid refrigerant. Subsequently, the liquid refrigerant enters the second electronic expansion valve 10 through the first branch of the second heat exchange element 9. Under the action of the second electronic expansion valve 10, it is throttled and depressurized, and converted into a low-temperature and low-pressure liquid refrigerant. Then it flows into the first branch of the third heat exchange element 11.

[0061] Within the third heat exchange element 11, the low-temperature, low-pressure liquid refrigerant in the first branch exchanges heat with the coolant in the second branch. After absorbing heat, the refrigerant evaporates, completing a phase change to form a low-temperature, low-pressure gaseous refrigerant, which returns to the first compressor 1 through the connecting path formed by ports a and c of the second three-way valve 12. During this heat exchange process, the coolant releases heat, and its temperature decreases. This achieves efficient and stable heat exchange between the refrigerant circulation system 100 and the coolant circulation system 300.

[0062] Similarly, please see Figure 5 With the first three-way valve 16 connected at ports a and c, the high-temperature and high-pressure refrigerant gas discharged from the second compressor 15 enters the first heat exchange element 5, and after condensation and heat release, it is converted into a high-pressure and medium-temperature liquid refrigerant. Subsequently, the liquid refrigerant enters the second electronic expansion valve 10 through the first branch of the second heat exchange element 9, and under the action of the second electronic expansion valve 10, it is throttled and depressurized, and converted into a low-temperature and low-pressure liquid refrigerant. Then it flows into the first branch of the third heat exchange element 11.

[0063] Within the third heat exchange element 11, the low-temperature, low-pressure liquid refrigerant in the first branch exchanges heat with the coolant in the second branch. After absorbing heat, the refrigerant evaporates, completing a phase change to form a low-temperature, low-pressure gaseous refrigerant, which returns to the second compressor 15 through the connecting path formed by ports a and b of the second three-way valve 12. Simultaneously, the coolant releases heat, lowering its temperature. This achieves efficient and stable heat exchange between the refrigerant circulation system 100 and the coolant circulation system 300.

[0064] Based on the above structure and working principle, when there is a low-temperature demand, the temperature control device 010 provided by the present invention can be switched to a two-stage compression operation mode to meet the requirements of low-temperature liquid supply; when there is no low-temperature demand, the first compressor 1 or the second compressor 15 can be selectively started separately according to the actual working conditions to achieve on-demand operation and achieve the purpose of energy saving.

[0065] Furthermore, the power of the first compressor 1 is W1, and the power of the second compressor 15 is W2, and the ratio of their powers satisfies: 2 < W1 / W2 < 4. Based on this, under the condition of medium-high temperature liquid supply in the coolant circulation system 300, different power compressors can be selectively started according to the magnitude of the cooling capacity demand to achieve on-demand operation, thereby effectively reducing energy consumption and improving the energy efficiency of the system. That is, in practical applications, the first compressor 1 can be enabled when the cooling capacity demand is large, and the second compressor 15 can be enabled when the cooling capacity demand is small. Preferably, the power ratio of the first compressor 1 to the second compressor 15 is 3 / 1, that is, W1 = 3W2.

[0066] In addition, please refer again to Figure 1 , the temperature control device 010 further includes a first temperature sensor 18 and a first pressure sensor 19, and the first temperature sensor 18 and the first pressure sensor 19 are connected to the inlet end of the first compressor 1. It can be understood that by simultaneously setting temperature and pressure sensors at the inlet end of the first compressor 1, the state parameters of the refrigerant entering the compressor (including temperature and pressure) can be monitored in real time and accurately, providing key operating data support for the system.

[0067] Specifically, according to the thermodynamic properties of the refrigerant, based on the pressure value measured by the first pressure sensor 19, the saturation temperature value corresponding to this pressure can be looked up; by comparing this saturation temperature with the suction temperature actually measured by the first temperature sensor 18, the superheat degree of the refrigerant can be calculated. By precisely controlling the superheat degree, when the second electronic expansion valve 10 adjusts the refrigerant flow rate, it can ensure that the refrigerant entering the first compressor 1 is in a fully vaporized state, avoid the risk of liquid hammer, ensure the stable operation of the compressor, and thus improve the safety of the system operation and the accuracy of temperature control.

[0068] Correspondingly, the temperature control device 010 further includes a second temperature sensor 13 and a second pressure sensor 14, and the second temperature sensor 13 and the second pressure sensor 14 are connected to the inlet end of the second compressor 15. Similar to the above, by simultaneously setting temperature and pressure sensors at the inlet end of the second compressor 15, the state parameters of the refrigerant entering the compressor (including temperature and pressure) can be monitored in real time and accurately, providing key operating data support for the system.

[0069] That is, based on the thermodynamic properties of the refrigerant and the pressure value measured by the second pressure sensor 14, the saturation temperature corresponding to that pressure can be retrieved. By comparing this saturation temperature with the suction temperature measured by the second temperature sensor 13, the superheat of the refrigerant can be calculated. By monitoring and controlling this superheat, it can be ensured that the refrigerant entering the second compressor 15 is fully vaporized, effectively preventing liquid slugging, ensuring the safe and stable operation of the compressor, and improving the overall control accuracy and reliability of the system.

[0070] Furthermore, such as Figure 1 As shown, in the coolant circulation system 300, a first one-way valve 2 is provided at the outlet end of the first compressor 1 to control the flow direction of the refrigerant and prevent it from flowing back. A fourth temperature sensor 3 and a fourth pressure sensor 4 are connected in series at the inlet end of the first pipeline of the first heat exchange element 5 to monitor the temperature and pressure of the refrigerant entering the heat exchange element in real time; its outlet end is connected in series with a fifth temperature sensor 6 and a liquid receiver 7 to detect the outlet temperature of the refrigerant after condensation and to realize gas-liquid separation and refrigerant storage.

[0071] The refrigerant flowing out of the receiver 7 is divided into two paths: one path enters the first electronic expansion valve 8 and participates in the first refrigerant circulation loop; the other path leads to the first branch of the second heat exchange element 9. A second one-way valve 17 is provided between the third pipeline of the second heat exchange element 9 and the inlet end of the first compressor 1 to ensure unidirectional flow of refrigerant, prevent reverse flow, and ensure the stability and reliability of system operation.

[0072] like Figure 6 As shown, the coolant circulation system 300 also includes a water tank 20, a circulation pump 21, and an electric heater, which are connected in series between the second branch outlet of the third heat exchange element 11 and the third temperature sensor 23, forming part of the coolant circulation loop. The water tank 20 stores coolant, the circulation pump 21 provides circulation power, and the electric heater provides auxiliary heating to the coolant when needed, enabling precise temperature control over a wide temperature range.

[0073] The following is based on Figure 1 Taking the temperature control device 010 shown as an example, the temperature control method provided by the embodiment of the present invention will be described exemplarily. Figure 7 As shown, Figure 7 This is a schematic diagram of the logic flow of the control method provided in an embodiment of the present invention. Specifically, the method includes:

[0074] S100 determines the current operating condition of the coolant circulation system 300.

[0075] In step S100, the controller determines the required supply temperature range for the coolant circulation system 300 based on current process requirements. According to actual application needs, the system operating conditions are divided into low-temperature supply conditions and medium-high-temperature supply conditions. Specifically, the low-temperature supply condition refers to the coolant temperature required by load 24 being relatively low, for example, between -45℃ and -25℃; the medium-high-temperature supply condition refers to the coolant temperature required by load 24 being in a relatively high range, such as between -20℃ and 80℃.

[0076] S210, if the coolant circulation system 300 is currently in a low-temperature supply condition, then control the first electronic expansion valve 8 to open, the a port and b port of the first three-way valve 16 to open, and the a port and b port of the second three-way valve 12 to open.

[0077] In step S210, when the system is determined to be in cryogenic liquid supply mode, the control system starts a two-stage compression refrigeration mode to meet the cryogenic demand. At this time, the controller outputs a control signal to control the first electronic expansion valve 8 to open, and simultaneously drives the first three-way valve 16 to switch to the ab open state, so that the high-temperature and high-pressure gaseous refrigerant discharged from the second compressor 15 flows into the third branch of the second heat exchange element 9; at the same time, the controller controls the second three-way valve 12 to switch to the ab open state, so that the low-temperature and low-pressure gaseous refrigerant flowing out from the first branch of the third heat exchange element 11 enters the inlet end of the second compressor 15 after passing through the second three-way valve 12.

[0078] In this configuration, the refrigerant circulation system 100 forms two refrigeration loops that work together: such as Figure 2 The diagram shows a first refrigerant circulation loop formed by a second branch of a first compressor 1, a first heat exchange element 5, a first electronic expansion valve 8, and a second heat exchange element 9 connected in series. (Example) Figure 3 The diagram shows a second refrigerant cooling cycle loop formed by connecting the first compressor 1, the first branch of the second heat exchange element 9, the first branch of the third heat exchange element 11, the second electronic expansion valve 10, the second compressor 15, and the third branch of the second heat exchange element 9 in series. These two loops achieve intermediate-stage heat exchange within the second heat exchange element 9, improving overall cycle efficiency, ensuring stable operation under low evaporation temperature conditions, rapidly responding to load changes 24, and achieving precise low-temperature control.

[0079] S230, if the coolant circulation system 300 is currently in a medium-high temperature coolant supply condition, then control the a port and c port of the second three-way valve 12 to be connected, or control the a port and c port of the first three-way valve 16 to be connected and the a port and b port of the second three-way valve 12 to be connected.

[0080] In step 230, when the system is in a medium-high temperature liquid supply condition, the cooling demand is relatively low, and there is no need to activate the two-stage compression. To reduce energy consumption and improve the energy efficiency ratio, the system can selectively start the first compressor 1 or the second compressor 15 according to the actual cooling capacity demand, and adjust the working state of the three-way valve accordingly to construct a single third or fourth refrigerant circulation loop.

[0081] Specifically, in the first sub-mode where the first compressor 1 operates alone, the controller controls the second three-way valve 12 to switch to the AC conducting state, allowing the gaseous refrigerant from the third heat exchange element 11 to flow to the inlet of the first compressor 1; at this time, the first three-way valve 16 can be in the AB conducting state to prevent refrigerant from flowing back into the second compressor 15. Figure 4 As shown, after being compressed by the first compressor 1, the refrigerant flows sequentially through the first heat exchange element 5, the first branch of the second heat exchange element 9, and the second electronic expansion valve 10, and enters the third heat exchange element 11 to absorb heat and evaporate. Finally, it returns to the first compressor 1, forming a third refrigerant circulation loop with the first compressor 1 as the core.

[0082] In the second sub-mode where the second compressor 15 operates independently, the controller controls the first three-way valve 16 to switch to the AC conducting state, allowing the high-temperature, high-pressure refrigerant discharged from the second compressor 15 to directly enter the first heat exchange element 5; simultaneously, it controls the second three-way valve 12 to switch to the Ab conducting state, allowing the evaporated refrigerant to return to the second compressor 15. For example... Figure 5 As shown, the refrigerant passes through the second compressor 15, the first heat exchange element 5, the first branch of the second heat exchange element 9, the second electronic expansion valve 10, and the first branch of the third heat exchange element 11 in sequence, and then returns to the second compressor 15, forming a fourth refrigerant circulation loop with the second compressor 15 as the core.

[0083] It should also be noted that the system can flexibly select either the first sub-mode or the second sub-mode according to the actual load demand to match different cooling capacity requirements. For example, under high load and large cooling demand conditions, the first sub-mode (i.e., the third refrigerant circulation loop with the first compressor 1 running alone) is activated; under low load and small cooling demand conditions, the system switches to the second sub-mode (i.e., the fourth refrigerant circulation loop with the second compressor 15 running alone).

[0084] Understandably, by starting and stopping compressors of different power as needed, energy consumption can be effectively reduced and energy waste can be avoided while ensuring temperature control accuracy, thereby achieving the operational goal of on-demand cooling and high-efficiency energy saving.

[0085] Furthermore, as described above, in some embodiments, the coolant circulation system 300 includes a load 24, a second branch of a third heat exchange element 11, and a third temperature sensor 23 connected in series. Meanwhile, the refrigerant circulation system 100 also includes a first temperature sensor 18, a first pressure sensor 19, a second temperature sensor 13, and a second pressure sensor 14.

[0086] It should be noted that the first temperature sensor 18 and the first pressure sensor 19 are connected in series at the inlet end of the first compressor 1; the second temperature sensor 13 and the second pressure sensor 14 are connected in series at the inlet end of the second compressor 15.

[0087] Therefore, as Figure 8 As shown, when the coolant circulation system 300 is currently operating under low-temperature supply conditions, the method further includes:

[0088] The third temperature setpoint SV0 of the third temperature sensor 23 is acquired in real time.

[0089] The value of SV0 ranges from -80℃ to +200℃. The specific value of SV0 is determined according to the actual processing requirements and is not limited here.

[0090] The third temperature measurement value PV0 of the third temperature sensor 23, the second temperature measurement value PV1 of the second temperature sensor 13, and the second pressure measurement value PV2 of the second pressure sensor 14 are acquired in real time.

[0091] PV0, PV1, and PV2 are all real-time dynamic values ​​that change over time and with the load 24.

[0092] The second pressure measurement value PV2 is converted into the saturation temperature value PV2' based on the pressure-enthalpy diagram;

[0093] The pressure-enthalpy diagram here is an embedded, programmed diagram, not a physical diagram. It refers to a module that is programmed and ready to be used. That is, by inputting any two values ​​of pressure, temperature, and enthalpy, the physical properties at that point can be automatically calculated. For example, by inputting the second temperature measurement value PV1 and the second pressure measurement value PV2, the saturation temperature value PV2' at that point can be obtained.

[0094] Calculate the difference X between the third temperature setpoint SV0 and the third temperature measured value PV0 (X=SV0-PV0), and the difference Y between the saturation temperature value PV2' and the second temperature measured value PV1 (Y=PV2'-PV1).

[0095] Determine the interval containing the difference X and the interval containing the difference Y;

[0096] If a≤X≤b and c≤Y≤d, then the opening degree of the second electronic expansion valve 10 is adjusted by M%; where M is a constant.

[0097] For example, in this embodiment, a = -0.5, b = 0.5, c = -10, d = -5, and M = 1. That is, if -0.5 ≤ X ≤ 0.5 and -10 ≤ Y ≤ -5, then the opening of the second electronic expansion valve 10 is adjusted by 1%. It should be noted that a, b, c, and d can also be set to other values. The values ​​of a, b, c, and d are determined according to the actual adjustment requirements and system loop, and are not limited here. The value of M is determined according to the temperature control accuracy, and is not limited here.

[0098] Furthermore, it should be noted that the adjustment direction (increase or decrease) of the opening of the second electronic expansion valve 10 is determined by the sign of the difference X. When the third temperature measurement value PV0 is greater than the third temperature set value SV0, it indicates that the actual liquid supply temperature is too high and the cooling capacity is insufficient. At this time, X is a negative value, and the control system determines that the refrigerant flow needs to be increased. Therefore, the opening of the second electronic expansion valve 10 is increased accordingly to increase the amount of refrigerant supplied to the third heat exchange element 11 and enhance the heat exchange effect. Conversely, when PV0 is less than SV0, it indicates that the temperature is too low and there is a risk of overcooling. At this time, X is a positive value, and the control system decreases the opening of the second electronic expansion valve 10 to reduce the refrigerant flow and avoid excessive cooling.

[0099] If c≤Y≤d, and Xb, then the PID program algorithm is called, the value of X is input into the PID program algorithm, and the opening of the second electronic expansion valve 10 is adjusted according to the PID algorithm.

[0100] That is, when Y is within the interval [c, d] and X is outside the interval [a, b], the system enters PID feedback control mode. The specific formula of the PID algorithm is shown below:

[0101] .

[0102] In the formula, Kp is the proportional gain, which is the reciprocal of the proportional gain; T t T is the integration time constant; D is the differential time constant; u(t) is the output signal of the PID controller, used to adjust the opening of the second electronic expansion valve 10; e(t) is the control deviation.

[0103] Under this condition, e(t) is the difference X.

[0104] If Y < c or Y > d, the PID program algorithm is invoked, the Y value is input into the PID program algorithm, and the opening of the second electronic expansion valve 10 is adjusted according to the PID algorithm.

[0105] That is, when Y is outside the interval [c, d], the system enters PID feedback control mode regardless of the state of X to ensure the normal operation of the second compressor 15. Under this condition, Y is preferentially satisfied, and e(t) is the difference Y.

[0106] Furthermore, it should be noted that when X is outside the interval [a, b], the PID program algorithm can be invoked, and the X value can be input into the PID program algorithm to adjust the speed of the first compressor 1, the speed of the second compressor 15, the opening degree of the first electronic expansion valve 8, and the power of the electric heating element 22 according to the PID algorithm.

[0107] For the first compressor 1 and the second compressor 15, when X < a (i.e. the actual temperature is higher than the set value and there is a positive temperature difference), the control system judges that the cooling demand is large and increases the operating speed of the compressor accordingly; when X > b, the compressor speed is reduced and the cooling output is reduced.

[0108] For the first electronic expansion valve 8, when X < a, it indicates that the coolant temperature is too high. Therefore, the opening of the first electronic expansion valve 8 should be reduced to increase the throttling pressure drop and optimize the heat exchange efficiency. When X > b, it indicates that the evaporation temperature is too low or the cooling capacity is excessive. Therefore, the opening of the first electronic expansion valve 8 should be increased to appropriately increase the refrigerant flow rate.

[0109] For the electric heating element 22, its power output adopts a positive deviation (X is a positive value) drive control strategy. When X > 0, the higher the percentage of output power of the electric heating element 22, the more auxiliary heating is achieved; when X < 0, the heating request is not valid, the electric heating element 22 stops working, and ineffective energy consumption is avoided.

[0110] Furthermore, please refer again. Figure 8 When the coolant circulation system 300 is currently operating under low-temperature supply conditions, the method further includes:

[0111] The first temperature measurement value PV3 of the first temperature sensor 18 and the first pressure measurement value PV4 of the first pressure sensor 19 are acquired in real time.

[0112] Both PV3 and PV4 are real-time dynamic values ​​that change with time and load 24.

[0113] The first pressure measurement value PV4 is converted into the saturation temperature value PV4' based on the pressure-enthalpy diagram;

[0114] Similarly, by inputting the first temperature measurement value PV3 and the first pressure measurement value PV4, the saturation temperature value PV4' at this point can be obtained.

[0115] Calculate the difference Z between the saturation temperature value PV4' and the first temperature measurement value PV3 (Z = PV4' - PV3);

[0116] Determine the interval in which the difference Z lies;

[0117] If Z < e or Z > f, then the PID program algorithm is invoked, the Z value is input into the PID program algorithm, and the opening degree of the first electronic expansion valve 8 is adjusted according to the PID algorithm.

[0118] That is, when Z is outside the interval [e, f], regardless of the state of X, the system enters PID feedback control mode to ensure the normal operation of the first compressor 1. Under this condition, Z and e(t) are preferentially satisfied as the difference Z.

[0119] Additionally, it should be noted that when the coolant circulation system 300 is in low-temperature supply mode and the two-stage compression refrigeration mode is activated, the second compressor 15 is started first. During the operation of the second compressor 15, the first pressure sensor 19 monitors the refrigerant pressure at the inlet of the first compressor 1 in real time. When the detected pressure value rises to the preset start-up threshold, it indicates that the refrigerant in the system has circulated sufficiently and the intermediate stage pressure has reached a stable state. At this time, the controller triggers the start-up command of the first compressor 1, putting it into operation.

[0120] like Figure 9 As shown, when the coolant circulation system 300 is currently operating under medium-high temperature coolant supply conditions, and ports a and c of the first three-way valve 16 are connected and ports a and b of the second three-way valve 12 are connected (i.e., in the second sub-mode where the second compressor 15 operates alone), the method further includes:

[0121] The third temperature setpoint SV0 of the third temperature sensor 23 is acquired in real time.

[0122] The third temperature measurement value PV0 of the third temperature sensor 23, the second temperature measurement value PV1 of the second temperature sensor 13, and the second pressure measurement value PV2 of the second pressure sensor 14 are acquired in real time.

[0123] The second pressure measurement value PV2 is converted into the saturation temperature value PV2' based on the pressure-enthalpy diagram;

[0124] Calculate the difference X between the third temperature setpoint SV0 and the third temperature measured value PV0, and the difference Y between the saturation temperature value PV2' and the second temperature measured value PV1;

[0125] Determine the interval containing the difference X and the interval containing the difference Y;

[0126] If a≤X≤b and c≤Y≤d, then the opening degree of the second electronic expansion valve 10 is adjusted by M%; where M is a constant.

[0127] If c≤Y≤d, and Xb, then the PID program algorithm is called, the value of X is input into the PID program algorithm, and the opening of the second electronic expansion valve 10 is adjusted according to the PID algorithm.

[0128] That is, when Y is within the interval [c, d] and X is outside the interval [a, b], the system enters PID feedback control mode. In this condition, e(t) is the difference X.

[0129] If Y < c or Y > d, the PID program algorithm is invoked, the Y value is input into the PID program algorithm, and the opening of the second electronic expansion valve 10 is adjusted according to the PID algorithm.

[0130] That is, when Y is outside the interval [c, d], the system enters PID feedback control mode regardless of the state of X to ensure the normal operation of the second compressor 15. Under this condition, Y is preferentially satisfied, and e(t) is the difference Y.

[0131] In addition, it should be noted that when X is outside the range of [a, b], the PID program algorithm can be called, and the X value can be input into the PID program algorithm. The speed of the second compressor 15 and the power of the electric heating element 22 can be adjusted according to the PID algorithm. The adjustment principle has been explained in detail above and will not be repeated here.

[0132] like Figure 10 As shown, when the coolant circulation system 300 is currently operating under medium-high temperature coolant supply conditions, and when ports a and c of the second three-way valve 12 are connected (in the first sub-mode where the first compressor 1 operates alone), the method further includes:

[0133] The third temperature setpoint SV0 of the third temperature sensor 23 is acquired in real time.

[0134] The third temperature measurement value PV0 of the third temperature sensor 23, the first temperature measurement value PV3 of the first temperature sensor 18, and the first pressure measurement value PV4 of the first pressure sensor 19 are acquired in real time.

[0135] The first pressure measurement value PV4 is converted into the saturation temperature value PV4' based on the pressure-enthalpy diagram;

[0136] Calculate the difference X between the third temperature setpoint SV0 and the third temperature measured value PV0, and the difference Z between the saturation temperature value PV4' and the first temperature measured value PV3;

[0137] Determine the interval containing the difference X and the interval containing the difference Z;

[0138] If a≤X≤b and e≤Z≤f, then the opening degree of the second electronic expansion valve 10 is adjusted by M%; where M is a constant.

[0139] If e≤Z≤f, and Xb, then the PID program algorithm is called, the value of X is input into the PID program algorithm, and the opening of the second electronic expansion valve 10 is adjusted according to the PID algorithm.

[0140] That is, when Z is within the interval [e, f] and X is outside the interval [a, b], the system enters PID feedback control mode. In this condition, e(t) is the difference X.

[0141] If Z < e or Z > f, then the PID program algorithm is invoked, the Z value is input into the PID program algorithm, and the opening degree of the second electronic expansion valve 10 is adjusted according to the PID algorithm.

[0142] That is, when Z is outside the interval [e, f], the system enters PID feedback control mode regardless of the state of X to ensure the normal operation of the first compressor 1. Under this condition, Z and e(t) are preferentially satisfied as the difference Z.

[0143] In addition, it should be noted that when X is outside the interval [a, b], the PID program algorithm can be called, and the X value can be input into the PID program algorithm. The speed of the first compressor 1 and the power of the electric heating element 22 can be adjusted according to the PID algorithm. The adjustment principle has been explained in detail above and will not be repeated here.

[0144] In summary, this invention provides a temperature control device 010 and a temperature control method. The temperature control device 010 includes a coolant circulation system 300 and a refrigerant circulation system 100. The temperature control device 010 can selectively construct a first refrigerant circulation loop and a second refrigerant circulation loop according to the required supply liquid temperature, enabling the first compressor 1 and the second compressor 15 to operate collaboratively for two-stage compression; or construct a third or fourth refrigerant circulation loop, using only one compressor for single-stage compression. Therefore, the temperature control device 010 provided by this invention can flexibly adjust the compressor configuration according to actual cooling capacity requirements, ensuring that the load 24 reaches the target temperature quickly and stably while avoiding excessive cooling capacity and energy waste, achieving efficient and energy-saving operation.

[0145] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A temperature control device, characterized by, It includes a coolant circulation system (300) and a refrigerant circulation system (100), and the refrigerant circulation system (100) is capable of forming at least one of a first refrigerant circulation loop, a second refrigerant circulation loop, a third refrigerant circulation loop and a fourth refrigerant circulation loop; The first refrigerant circulation loop includes a second branch consisting of a first compressor (1), a first heat exchange element (5), a first electronic expansion valve (8), and a second heat exchange element (9) connected in series. The second refrigerant circulation loop includes the first compressor (1), the first heat exchange element (5), the first branch of the second heat exchange element (9), the second electronic expansion valve (10), the first branch of the third heat exchange element (11), the second compressor (15), and the third branch of the second heat exchange element (9) connected in series. The third refrigerant circulation loop includes the first compressor (1), the first heat exchange element (5), the first branch of the second heat exchange element (9), the second electronic expansion valve (10), and the first branch of the third heat exchange element (11), which are connected in series. The fourth refrigerant circulation loop includes the second compressor (15), the first heat exchange element (5), the first branch of the second heat exchange element (9), the second electronic expansion valve (10), and the first branch of the third heat exchange element (11), which are connected in series. The refrigerant circulation system (100) also includes: The first three-way valve (16) includes port a, port b and port c; wherein port a of the first three-way valve (16) is connected to the outlet end of the second compressor (15), port b is connected to the inlet end of the third branch of the second heat exchange element (9), and port c is connected to the outlet end of the first compressor (1). The second three-way valve (12) includes port a, port b and port c; wherein port a of the second three-way valve (12) is connected to the outlet end of the first branch of the third heat exchange element (11), port b is connected to the inlet end of the second compressor (15), and port c is connected to the inlet end of the first compressor (1).

2. The temperature control device according to claim 1, characterized in that, When the coolant circulation system (300) is in a low-temperature supply condition, the first electronic expansion valve (8) is turned on, and at the same time, the a port and b port of the first three-way valve (16) are turned on, and the a port and b port of the second three-way valve (12) are turned on, so that the refrigerant circulation system (100) can simultaneously form the first refrigerant circulation loop and the second refrigerant circulation loop; When the coolant circulation system (300) is in a medium-high temperature supply condition, the a port and c port of the second three-way valve (12) are connected, so that the refrigerant circulation system (100) can form the third refrigerant circulation loop; or, the a port and c port of the first three-way valve (16) are connected, and the a port and b port of the second three-way valve (12) are connected, so that the refrigerant circulation system (100) can form the fourth refrigerant circulation loop.

3. The temperature control device according to claim 1 or 2, characterized in that, The power of the first compressor (1) is W1, and the power of the second compressor (15) is W2. The power ratio of the two compressors satisfies: 4 > W1 / W2 > 2.

4. A temperature control method, characterized in that, Applied to the temperature control device (010) according to claim 1 or 2, the method includes: Determine the current operating condition of the coolant circulation system (300); If the coolant circulation system (300) is currently in a low-temperature supply condition, then the first electronic expansion valve (8) is turned on, the a port and b port of the first three-way valve (16) are turned on, and the a port and b port of the second three-way valve (12) are turned on. If the coolant circulation system (300) is currently in a medium-high temperature coolant supply condition, then control the a port and c port of the second three-way valve (12) to be connected, or control the a port and c port of the first three-way valve (16) to be connected and the a port and b port of the second three-way valve (12) to be connected.

5. The temperature control method according to claim 4, characterized in that, The coolant circulation system (300) includes a load (24) connected in series, a second branch of the third heat exchange element (11), and a third temperature sensor (23). The refrigerant circulation system (100) further includes a first temperature sensor (18), a first pressure sensor (19), a second temperature sensor (13), and a second pressure sensor (14); the first temperature sensor (18) and the first pressure sensor (19) are connected in series at the inlet end of the first compressor (1); the second temperature sensor (13) and the second pressure sensor (14) are connected in series at the inlet end of the second compressor (15).

6. The temperature control method according to claim 5, characterized in that, When the coolant circulation system (300) is currently operating under cryogenic supply conditions, the method further includes: The third temperature setpoint SV0 of the third temperature sensor (23) is acquired in real time; The third temperature measurement value PV0 of the third temperature sensor (23), the second temperature measurement value PV1 of the second temperature sensor (13) and the second pressure measurement value PV2 of the second pressure sensor (14) are acquired in real time. The second pressure measurement value PV2 is converted into the saturation temperature value PV2' based on the pressure-enthalpy diagram; Calculate the difference X between the third temperature setpoint SV0 and the third temperature measured value PV0, and the difference Y between the saturation temperature value PV2' and the second temperature measured value PV1; Determine the interval in which the difference X lies and the interval in which the difference Y lies; If a≤X≤b and c≤Y≤d, then the opening degree of the second electronic expansion valve (10) is adjusted by M%; where M is a constant. If c≤Y≤d, and Xb, then call the PID program algorithm, input the X value into the PID program algorithm, and adjust the opening of the second electronic expansion valve (10) according to the PID algorithm; If Y < c or Y > d, then the PID program algorithm is invoked, the Y value is input into the PID program algorithm, and the opening degree of the second electronic expansion valve (10) is adjusted according to the PID algorithm.

7. The temperature control method according to claim 6, characterized in that, When the coolant circulation system (300) is currently operating under cryogenic supply conditions, the method further includes: The first temperature measurement value PV3 of the first temperature sensor (18) and the first pressure measurement value PV4 of the first pressure sensor (19) are acquired in real time. The first pressure measurement value PV4 is converted into the saturation temperature value PV4' based on the pressure-enthalpy diagram; Calculate the difference Z between the saturation temperature value PV4' and the first temperature measurement value PV3; Determine the interval in which the difference Z lies; If Z < e or Z > f, then the PID program algorithm is invoked, the Z value is input into the PID program algorithm, and the opening degree of the first electronic expansion valve (8) is adjusted according to the PID algorithm.

8. The temperature control method according to claim 5, characterized in that, When the coolant circulation system (300) is currently operating under medium-high temperature coolant supply conditions, and the first three-way valve (16) is connected between port a and port c, and the second three-way valve (12) is connected between port a and port b, the method further includes: The third temperature setpoint SV0 of the third temperature sensor (23) is acquired in real time; The third temperature measurement value PV0 of the third temperature sensor (23), the second temperature measurement value PV1 of the second temperature sensor (13) and the second pressure measurement value PV2 of the second pressure sensor (14) are acquired in real time. The second pressure measurement value PV2 is converted into the saturation temperature value PV2' based on the pressure-enthalpy diagram; Calculate the difference X between the third temperature setpoint SV0 and the third temperature measured value PV0, and the difference Y between the saturation temperature value PV2' and the second temperature measured value PV1; Determine the interval in which the difference X lies and the interval in which the difference Y lies; If a≤X≤b and c≤Y≤d, then the opening degree of the second electronic expansion valve (10) is adjusted by M%; where M is a constant. If c≤Y≤d, and Xb, then call the PID program algorithm, input the X value into the PID program algorithm, and adjust the opening of the second electronic expansion valve (10) according to the PID algorithm; If Y < c or Y > d, then the PID program algorithm is invoked, the Y value is input into the PID program algorithm, and the opening degree of the second electronic expansion valve (10) is adjusted according to the PID algorithm.

9. The temperature control method according to claim 5, characterized in that, When the coolant circulation system (300) is currently operating under medium-high temperature coolant supply conditions, and when ports a and c of the second three-way valve (12) are connected, the method further includes: The third temperature setpoint SV0 of the third temperature sensor (23) is acquired in real time; The third temperature measurement value PV0 of the third temperature sensor (23), the first temperature measurement value PV3 of the first temperature sensor (18) and the first pressure measurement value PV4 of the first pressure sensor (19) are acquired in real time. The first pressure measurement value PV4 is converted into the saturation temperature value PV4' based on the pressure-enthalpy diagram; Calculate the difference X between the third temperature setpoint SV0 and the third temperature measured value PV0, and the difference Z between the saturation temperature value PV4' and the first temperature measured value PV3; Determine the interval in which the difference X lies and the interval in which the difference Z lies; If a≤X≤b and e≤Z≤f, then the opening degree of the second electronic expansion valve (10) is adjusted by M%; where M is a constant. If e≤Z≤f, and Xb, then call the PID program algorithm, input the X value into the PID program algorithm, and adjust the opening of the second electronic expansion valve (10) according to the PID algorithm; If Z < e or Z > f, then the PID program algorithm is invoked, the Z value is input into the PID program algorithm, and the opening degree of the second electronic expansion valve (10) is adjusted according to the PID algorithm.

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