Extremely low temperature rapid and accurate temperature control system based on cascade refrigeration and TEC temperature control chip

Abstract

The invention relates to the technical field of automatic temperature control, and discloses an extremely low temperature rapid and accurate temperature control system which is used in the fields of biomedical treatment, semiconductor testing and the like and integrates cooperative work of cascade refrigeration equipment and a thermoelectric refrigeration (TEC) chip. According to the technical scheme, the advantages of a cascade refrigeration chip and a thermoelectric refrigeration (TEC) chip are ingeniously fused, first-stage rapid cooling is achieved through the cascade refrigeration system, when the temperature is close to the target temperature, the cascade refrigeration chip and the TEC chip are switched to work cooperatively for high-precision fine adjustment, and perfect transition from rapid cooling to high-precision fine adjustment is achieved. The problems that a traditional extremely low temperature control system is high in energy consumption, slow in response and insufficient in precision are solved. According to the invention, dynamic switching logic and a cooperative control algorithm are combined, joint debugging and joint control are carried out on cascade refrigeration and TEC chip refrigeration, and the temperature control efficiency and stability are obviously improved.

Description

Technical Field

[0001] The present invention relates to the field of automated temperature control, and more specifically, to an ultra-low temperature rapid and precise temperature control system based on cascade refrigeration and a TEC temperature control chip. Background Art

[0002] Currently, the demand for ultra-low temperature control technology is urgent in fields such as biomedicine and semiconductor testing. Traditional solutions mainly rely on multi-stage compression refrigeration systems for cooling, but they are prone to temperature fluctuations (above ±0.5°C) due to frequent start and stop of the compressor when approaching the target temperature. Although the TEC chip can achieve a temperature control accuracy of ±0.1°C, its refrigeration power is limited and it is difficult to independently support the rapid cooling demand in an ultra-low temperature environment.

[0003] At the same time, existing cascade refrigeration systems need to frequently start and stop the compressor when approaching the target temperature, with high energy consumption, serious temperature overshoot, and the temperature control accuracy being affected by the phase change hysteresis of the refrigerant, unable to meet the requirements of precision temperature control scenarios. For a pure TEC temperature control solution, due to its low refrigeration power, it cannot independently achieve rapid cooling below -60°C, and the efficiency of the TEC decreases during high-load operation, requiring an additional heat dissipation system.

[0004] Therefore, it is necessary to develop a combined temperature control system of cascade refrigeration and a TEC chip and achieve coordinated control of the two. Summary of the Invention

[0005] The purpose of the present invention is to provide an ultra-low temperature rapid and precise temperature control system based on cascade refrigeration and a TEC temperature control chip to solve the problems raised in the above background art.

[0006] An ultra-low temperature rapid and precise temperature control system based on cascade refrigeration and a TEC temperature control chip,

[0007] comprising a cascade refrigeration module, a TEC temperature control module, and a coordinated control unit;

[0008] wherein the cascade refrigeration module includes a primary compression refrigeration system and a secondary compression refrigeration system for rapidly cooling to near the target temperature in the initial stage,

[0009] the TEC temperature control module is integrated at the end of the primary compression refrigeration system and the end of the secondary compression refrigeration system, and realizes fine tuning of ±0.1°C through thermoelectric refrigeration;

[0010] Coordinated control unit: Based on the feedback of the temperature sensor, dynamically switch the refrigeration modes of the compressor and the TEC chip and adjust the power distribution.

[0011] Furthermore: a primary compression refrigeration system, where the outlet of the first compressor is connected to the inlet of the condenser, the outlet of the condenser is branched into two paths and respectively connected to the inlets of the first electronic expansion valve and the second electronic expansion valve, the outlet of the first electronic expansion valve is connected to the right - hand side inlet of the plate heat exchanger, the right - hand side outlet of the plate heat exchanger is connected to the inlet of the first compressor, the outlet of the second electronic expansion valve is connected to the inlet of the coil inside the first fluorinated liquid storage tank, and the coil outlet is connected to the inlet of the first compressor;

[0012] A secondary compression system, where the outlet of the second compressor is connected to the left - hand side inlet of the plate heat exchanger, the left - hand side outlet of the plate heat exchanger is connected to the inlet of the third electronic expansion valve, the outlet of the third electronic expansion valve is connected to the inlet of the coil inside the second fluorinated liquid storage tank, and the coil outlet is connected to the inlet of the second compressor;

[0013] A primary fluorinated liquid circulation system, where the outlet of the first fluorinated liquid storage tank is connected to the inlet of the first circulation pump, the outlet of the first circulation pump is connected to the inlet of the coil of the TEC heat exchange device, and the coil outlet is connected to the inlet of the first fluorinated liquid storage tank;

[0014] A secondary fluorinated liquid circulation system, where the outlet of the second fluorinated liquid storage tank is connected to the inlet of the heat exchanger of the TEC heat exchange device, the outlet of the heat exchanger is connected to the inlet of the second circulation pump, the outlet of the second circulation pump is connected to the inlet of the workbench, and the workbench outlet is connected to the inlet of the second fluorinated liquid storage tank;

[0015] Both the first fluorinated liquid storage tank and the second fluorinated liquid storage tank are provided with coils. Inside the coils is gaseous refrigerant, and outside the coils is liquid fluorinated liquid;

[0016] The right - hand side of the plate heat exchanger is gaseous refrigerant, and the left - hand side is liquid refrigerant;

[0017] Both the coil and the heat exchanger of the TEC heat exchange device are filled with liquid fluorinated liquid.

[0018] Furthermore: temperature sensors are installed at the inlet and outlet of the plate heat exchanger.

[0019] Furthermore: the first fluorinated liquid storage tank is provided with a copper coil. The coil is embedded inside the storage tank. Inside the coil is gaseous refrigerant, and outside is liquid fluorinated liquid.

[0020] Furthermore: the second fluorinated liquid storage tank is provided with a copper coil. The coil is embedded inside the storage tank. Inside the coil is gaseous refrigerant, and outside is liquid fluorinated liquid.

[0021] Furthermore: the plate heat exchanger is a brazed plate heat exchanger. Each side of the heat exchanger is provided with a pair of inlets and outlets. The left - hand side inlet is connected to the outlet of the second compressor and conducts gaseous refrigerant, and the right - hand side inlet is connected to the first electronic expansion valve and conducts gaseous refrigerant.

[0022] Furthermore: the TEC heat exchange device includes a plate evaporator, a TEC chip, a fin heat sink and an upper shell. The upper end of the plate evaporator is provided with a groove, the TEC chip is installed in the groove, and the fin heat sink is installed on the upper end of the TEC chip; there are several grooves, and each groove is adapted for a TEC chip, and the TEC chips are connected in parallel with each other; the upper shell includes an inlet and an outlet, and the upper shell is fixed to the upper end of the plate evaporator.

[0023] Furthermore: guide plates are provided on both sides of the interior of the upper shell.

[0024] Furthermore: a movable plate is provided at the upper end of the upper shell, a slider is provided on one side of the upper shell, one end of the slider is fixedly connected to a first connecting rod and a second connecting rod, one end of the first connecting rod is fixedly connected to the lower end of the TEC chip, and the second connecting rod is fixedly connected to the lower end of the movable plate, and a connecting groove is provided on the inner side of the TEC chip; a connecting piece is provided on the inner side of the groove, and the connecting groove and the connecting piece can be electrically connected after being plugged in.

[0025] Furthermore: the movable plate includes a side plate and a top plate, one end of the side plate is movably connected to the upper shell, and the other end of the side plate is movably connected to the top plate, the side plate structure is two plate bodies that are socketed together, and the plate bodies can slide relative to each other to adjust the length of the side plate, one side of the top plate is fixedly connected to a limit rod, one side of the limit rod is fixedly connected to the upper shell, and the limit rod is also composed of two slidable and retractable rod bodies; the area where the first connecting rod passes through the inner wall of the plate evaporator is adaptively provided with a hole groove.

[0026] Beneficial effects

[0027] 1. Dynamic threshold switching mechanism: Automatically calculate the cascade cooling operating power and TEC entry point based on the target temperature.

[0028] 2. Cold coupling design: Use the cold capacity of the first-stage compression system to provide a heat dissipation environment for the TEC heat exchange module, effectively assisting the TEC chip to cool the fluorinated liquid and improve overall energy efficiency; it can quickly achieve accurate cooling.

[0029] 3. After verification through test experiments, the number of connected TEC chips can be adjusted according to actual needs, and the changes in the internal structure of the upper shell can be linked to change the air flow path to maximize the efficiency of the TEC chip. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 Schematic diagram of the system flow of the present invention;

[0031] Figure 2 Schematic diagram of the TEC heat exchange device of the present invention;

[0032] Figure 3 This is the side view of the TEC heat exchange device of the present invention;

[0033] Figure 4 This is the schematic diagram of the upper groove structure of the plate evaporator of the present invention;

[0034] Figure 5 This is the schematic diagram of the connection between the TEC chip and the fin radiator of the present invention;)]

[0035] Figure 6 This is the schematic diagram of the series connection structure of the TEC chips of the present invention;

[0036] Figure 7 This is the schematic diagram of the regulation of the number of TEC chips connected in the present invention;

[0037] Figure 8 This is the schematic diagram of the movable plate structure of the present invention;

[0038] Figure 9 This is the graph of the relationship between the cooling efficiency and the number of TEC chips connected;

[0039] Figure 10 For Figure 8 This is the enlarged view of the structure of area A.

[0040] Explanation of the reference numerals in the figure: 1, workbench; 2, second fluorinated liquid storage tank; 3, second compressor; 4, plate heat exchanger; 5, first compressor; 6, condenser; 7, first electronic expansion valve; 8, second electronic expansion valve; 9, first fluorinated liquid storage tank; 10, first circulation pump; 11, TEC heat exchange device; 12, second circulation pump; 13, third electronic expansion valve; 111, plate evaporator; 112, groove; 113, TEC chip; 114, fin radiator; 115, upper housing; 116, sliding buckle; 117, first connecting rod; 118, second connecting rod; 119, connecting groove; 1110, connecting piece; 1111, movable plate; 1112, side plate; 1113, top plate; 114, limiting rod. Detailed implementation manners

[0041] In the description of the present invention, it should be understood that the orientation or positional relationships indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. are based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention.

[0042] In the description of the present invention, "a plurality of" means two or more, unless otherwise specifically defined.

[0043] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "equipped with", "sheathed / connected", "connected", etc. should be understood in a broad sense. For example, "connected" 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 directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0044] Embodiment 1

[0045] Please refer to Figures 1-6 , the present invention provides a technical solution:

[0046] A cryogenic rapid and precise temperature control system based on cascade refrigeration and TEC temperature control chips,

[0047] including a cascade refrigeration module, a TEC temperature control module and a cooperative control unit;

[0048] wherein the cascade refrigeration module includes a primary compression refrigeration system and a secondary compression refrigeration system for rapidly cooling to near the target temperature in the initial stage,

[0049] the TEC temperature control module is integrated at the end of the primary compression refrigeration system and the end of the secondary compression refrigeration system, and realizes fine adjustment of ±0.1 °C through thermoelectric refrigeration;

[0050] Cooperative control unit: Based on the feedback of the temperature sensor, dynamically switch the refrigeration modes of the compressor and the TEC chip and adjust the power distribution.

[0051] Primary compression refrigeration system, the outlet of the first compressor is connected to the inlet of the condenser, the outlet of the condenser is divided into two paths and respectively connected to the inlets of the first electronic expansion valve and the second electronic expansion valve, the outlet of the first electronic expansion valve is connected to the right inlet of the plate heat exchanger, the right outlet of the plate heat exchanger is connected to the inlet of the first compressor, the outlet of the second electronic expansion valve is connected to the inlet of the inner coil of the first fluorinated liquid storage tank, and the coil outlet is connected to the inlet of the first compressor;

[0052] Secondary compression system, the outlet of the second compressor is connected to the left inlet of the plate heat exchanger, the left outlet of the plate heat exchanger is connected to the inlet of the third electronic expansion valve, the outlet of the third electronic expansion valve is connected to the inlet of the inner coil of the second fluorinated liquid storage tank, and the coil outlet is connected to the inlet of the second compressor;

[0053] The primary fluorinated liquid circulation system, the outlet of the first fluorinated liquid storage tank is connected to the inlet of the first circulation pump, the outlet of the first circulation pump is connected to the inlet of the coil of the TEC heat exchange device, and the coil outlet is connected to the inlet of the first fluorinated liquid storage tank;

[0054] The secondary fluorinated liquid circulation system, the outlet of the second fluorinated liquid storage tank is connected to the inlet of the heat exchanger of the TEC heat exchange device, the heat exchanger outlet is connected to the inlet of the second circulation pump, the outlet of the second circulation pump is connected to the inlet of the workbench, and the workbench outlet is connected to the inlet of the second fluorinated liquid storage tank;

[0055] Coils are provided in both the first fluorinated liquid storage tank and the second fluorinated liquid storage tank. The inside of the coil is a gas refrigerant, and the outside of the coil is a liquid fluorinated liquid;

[0056] On the right side of the plate heat exchanger is a gas refrigerant, and on the left side is a liquid refrigerant;

[0057] Both the coil and the heat exchanger of the TEC heat exchange device are filled with liquid fluorinated liquid.

[0058] Temperature sensors are installed at the inlet and outlet of the plate heat exchanger.

[0059] A copper coil is provided in the first fluorinated liquid storage tank. The coil is embedded inside the storage tank. The inside of the coil is passed through by a gas refrigerant, and the outside is a liquid fluorinated liquid. ,

[0060] A copper coil is provided in the second fluorinated liquid storage tank. The coil is embedded inside the storage tank. The inside of the coil is passed through by a gas refrigerant, and the outside is a liquid fluorinated liquid.

[0061] The plate heat exchanger is a brazed plate heat exchanger. There is a pair of inlets and outlets on each side of the heat exchanger. The left inlet is connected to the outlet of the second compressor and is passed through by a gas refrigerant. The right inlet is connected to the first electronic expansion valve and is passed through by a gas refrigerant.

[0062] The TEC heat exchange device includes a plate evaporator, a TEC chip, a fin radiator, and an upper housing. A groove is provided at the upper end of the plate evaporator. The TEC chip is installed in the groove. The fin radiator is installed on the upper end of the TEC chip; There are several grooves, and each groove is adapted to a TEC chip. The TEC chips are connected in parallel with each other; The upper housing includes an inlet and an outlet, and the upper housing is fixed on the upper end of the plate evaporator.

[0063] Flow guiding plates are provided on both sides inside the upper housing; The setting of the flow guiding plates can make the gas pass through the heat dissipation fins more quickly.

[0064] For the operating logic of the above structure, taking the workbench cooling down to -60°C as an example. The system first enters the rapid cooling stage: the primary compression system will start first. Temperature sensors are installed at the inlet and outlet of the plate heat exchanger. After the temperature sensor in the plate heat exchanger detects that the temperature drops to the set threshold of -30±2°C, the secondary compression system will be started. At this time, the secondary compression system will cool the fluorinated liquid in the second fluorinated liquid storage tank. At the same time, the control system will adjust the opening degree of the first electronic expansion valve, and then stabilize the temperature at the inlet and outlet of the plate heat exchanger within the set threshold range of -30±2°C. The plate heat exchanger serves as both the evaporator of the primary compression system and the condenser of the secondary compression system to cool the secondary compression system. A temperature sensor is installed in the second fluorinated liquid storage tank. The secondary compression system controls the temperature of the fluorinated liquid storage tank within the set threshold range (-59±1°C) by controlling the opening degree of the third electronic expansion valve. During this process, the second circulation pump will be started to circulate the fluorinated liquid in the machine table and the second fluorinated liquid storage tank. At the same time, the control system will conduct joint adjustment and control of the first compressor, the second compressor, the first electronic expansion valve, and the third electronic expansion valve, so as to stabilize the temperature in the second fluorinated liquid storage tank within -59±1°C. Then, the control system will send an instruction to adjust the opening degree of the second electronic expansion valve to cool the fluorinated liquid in the first fluorinated liquid storage tank. A temperature sensor is installed in the first fluorinated liquid storage tank. When the temperature sensor detects that the temperature reaches the set target temperature of -30±2°C, the first circulation pump and the TEC chip will be started. At this time, the TEC heat exchange device is in a slow cooling state, and under the action of the second circulation pump, the liquid in the second fluorinated liquid storage tank is slowly cooled until the outlet temperature of the second fluorinated liquid storage tank reaches the set threshold of -60°C. At this time, the system stabilizes the fluorinated liquid outlet temperature at -60±0.1°C by adjusting the power of the TEC chip.

[0065] Example 2

[0066] Reference Figures 7-10 :

[0067] In subsequent experiments, we found that in the initial state, the cooling rate has a greater correlation with the number of TEC chips connected. When the number of TECs connected reaches a certain level, the correlation of the increase in its cooling rate is significantly reduced. Therefore, the engineer thought that in a certain specific environment, selecting a specific number of TEC chips can achieve relatively low power consumption while realizing rapid cooling.

[0068] So we proposed a technical concept and found through simple simulation experiments that it is feasible, that is, the number of TECs connected can be controllably adjusted, allowing users to choose energy-saving cooling with relatively low power and slow speed or high-power rapid cooling according to their usage needs. However, no matter which of the above schemes is selected, it is better than the cooling effect of the existing technology.

[0069] According to the above conjecture and implementation, its structure is now described, and the details of the specific implementation means are uniformly processed. For example, the connection simulation experiment between the connecting rod and the TEC chip uses glue fixation, and the description here is all fixed connection, not specifically referring to glue fixation.

[0070] As follows:

[0071] An activity plate is provided at the upper end of the upper shell. A sliding buckle is provided on one side of the upper shell. One end of the sliding buckle is fixedly connected to a first connecting rod and a second connecting rod. One end of the first connecting rod is fixedly connected to the lower end of the TEC chip. The second connecting rod is fixedly connected to the lower end of the activity plate. A connecting groove is provided inside the TEC chip; a connecting piece is provided inside the groove. Electrical connection can be achieved after the connecting groove and the connecting piece are inserted.

[0072] The activity plate includes a side plate and a top plate. One end of the side plate is movably connected to the upper shell, and the other end of the side plate is movably connected to the top plate. The side plate structure is two plate bodies sleeved together, and the plate bodies can slide relative to each other to adjust the length of the side plate; a limiting rod is fixedly connected to one side of the top plate, and the limiting rod is fixedly connected to the upper shell on one side, and the limiting rod is also composed of two slidable and telescopic rod bodies.

[0073] Hole grooves are adaptively provided in the areas where the first connecting rod passes through the inner wall of the plate-type evaporator.

[0074] Through the setting of the above structure, a controllable access to the TEC chip can be realized through a simple mechanical structure; and at the same time, it can cooperate with the access and ejection of the TEC chip to change the internal air flow channel. When the TEC chip ejects, the top plate of the corresponding area fits against the inner wall of the upper shell, making the air flow channel wider. Under the condition that the gas unit time flow rate remains unchanged, the air can be more fully mixed, making the gas with uneven temperature distribution after the front-stage heat dissipation fins treatment relatively mixed sufficiently. When the TEC chip is accessed, the flow channel width is reduced to increase the flow rate and improve the heat exchange efficiency.

[0075] At the same time, the controllable access of the TEC can access the number of TEC chips according to the user's needs. Among them, a more preferred access scheme is intermittent access; for example, the TEC chips are accessed in the order of 1 / 3 / 5 / 7.

[0076] Reference Figure 9 , Cooling efficiency = that is, the temperature drop (starting temperature - cooling temperature) / (number of chips * cooling time). For example,

[0077] The temperature drops by 10°, and one chip takes 1 minute. At this time, the cooling efficiency ratio is 10 / (1 * 1) = 10.

[0078] For the same 10° temperature drop, two chips require 0.6 min, and the efficiency ratio at this time is 10 / (2*0.6)≈8.3.

[0079] Therefore, the cooling efficiency ratio gradually decreases as the number of chips increases. Defining the cooling efficiency of a single chip for temperature reduction as 1 cooling efficiency coefficient, a curve of the cooling efficiency coefficient versus the number of chips can be obtained.

[0080] Among them, the structure of the limit rod is a telescopic rod formed by sleeving an inner tube and an outer tube to achieve sliding expansion and contraction in the vertical direction.

[0081] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. The above embodiments and the descriptions in the specification are only preferred examples of the present invention and are not used to limit the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed. The scope of the present invention claimed is defined by the appended claims and their equivalents.

Claims

1. An ultra-low temperature rapid and precise temperature control system based on cascade refrigeration and TEC temperature control chips, characterized in that: It includes a cascade refrigeration module, a TEC temperature control module and a collaborative control unit; Among them, the cascade refrigeration module includes a first-stage compression refrigeration system and a second-stage compression refrigeration system for quickly cooling to near the target temperature in the initial stage. The TEC temperature control module is integrated at the end of the first-stage compression refrigeration system and the end of the second-stage compression refrigeration system, and realizes fine-tuning at the level of ±0.1°C through thermoelectric refrigeration; Collaborative control unit: Based on the feedback of the temperature sensor, dynamically switch the refrigeration modes of the compressor and the TEC chip and adjust the power distribution.

2. An ultra-low temperature rapid and precise temperature control system based on cascade refrigeration and TEC temperature control chips according to claim 1, characterized in that: For the first-stage compression refrigeration system, the outlet of the first compressor is connected to the inlet of the condenser, and the outlet of the condenser is divided into two paths and respectively connected to the inlets of the first electronic expansion valve and the second electronic expansion valve. The outlet of the first electronic expansion valve is connected to the right inlet of the plate heat exchanger, the right outlet of the plate heat exchanger is connected to the inlet of the first compressor, the outlet of the second electronic expansion valve is connected to the inlet of the coil in the first fluorinated liquid storage tank, and the coil outlet is connected to the inlet of the first compressor; For the second-stage compression system, the outlet of the second compressor is connected to the left inlet of the plate heat exchanger, the left outlet of the plate heat exchanger is connected to the inlet of the third electronic expansion valve, the outlet of the third electronic expansion valve is connected to the inlet of the coil in the second fluorinated liquid storage tank, and the coil outlet is connected to the inlet of the second compressor; For the first-stage fluorinated liquid circulation system, the outlet of the first fluorinated liquid storage tank is connected to the inlet of the first circulation pump, the outlet of the first circulation pump is connected to the inlet of the coil of the TEC heat exchange device, and the coil outlet is connected to the inlet of the first fluorinated liquid storage tank; For the second-stage fluorinated liquid circulation system, the outlet of the second fluorinated liquid storage tank is connected to the inlet of the heat exchanger of the TEC heat exchange device, the outlet of the heat exchanger is connected to the inlet of the second circulation pump, the outlet of the second circulation pump is connected to the inlet of the workbench, and the outlet of the workbench is connected to the inlet of the second fluorinated liquid storage tank; Coils are provided in both the first fluorinated liquid storage tank and the second fluorinated liquid storage tank. The inside of the coil is a gas refrigerant, and the outside of the coil is a liquid fluorinated liquid; The right side of the plate heat exchanger is a gas refrigerant, and the left side is a liquid refrigerant; Both the coil and the heat exchanger of the TEC heat exchange device are filled with liquid fluorinated liquid.

3. The cryogenic rapid and precise temperature control system based on cascade refrigeration and TEC temperature control chip according to claim 2, characterized in that: Temperature sensors are installed at the inlets and outlets of the plate heat exchanger.

4. A cryogenic rapid and precise temperature control system based on cascade refrigeration and a TEC temperature control chip according to claim 3, characterized in that: A copper coil is provided in the first fluorinated liquid storage tank. The coil is embedded inside the storage tank. The inside of the coil passes through a gas refrigerant, and the outside is a liquid fluorinated liquid.

5. The ultra-low temperature rapid and precise temperature control system based on cascade refrigeration and TEC temperature control chip according to claim 4, characterized in that: A copper coil is provided in the second fluorinated liquid storage tank. The coil is embedded inside the storage tank. The inside of the coil passes through a gas refrigerant, and the outside is a liquid fluorinated liquid.

6. The ultra-low temperature rapid and precise temperature control system based on cascade refrigeration and TEC temperature control chip according to claim 5, characterized in that: The plate heat exchanger is a brazed plate heat exchanger. A pair of inlets and outlets are provided on each of the left and right sides of the heat exchanger. The left inlet is connected to the outlet of the second compressor and passes through a gas refrigerant, and the right inlet is connected to the first electronic expansion valve and passes through a gas refrigerant.

7. An ultra-low temperature rapid and precise temperature control system based on cascade refrigeration and TEC temperature control chips according to claim 3, characterized in that: The TEC heat exchange device includes a plate evaporator, a TEC chip, a fin radiator, and an upper housing. A groove is provided at the upper end of the plate evaporator, and the TEC chip is installed in the groove. The fin radiator is installed on the upper end of the TEC chip. A plurality of grooves are provided, and each groove is adapted to one TEC chip. The TEC chips are connected in parallel with each other. The upper housing includes an inlet and an outlet, and the upper housing is fixed to the upper end of the plate evaporator.

8. The cryogenic rapid and precise temperature control system based on cascade refrigeration and TEC temperature control chip according to claim 7, characterized in that: Flow guiding plates are provided on both sides inside the upper housing.

9. The cryogenic rapid and precise temperature control system based on cascade refrigeration and TEC temperature control chip according to claim 8, wherein: An activity plate is provided at the upper end of the upper housing, and a sliding buckle is provided on one side of the upper housing. One end of the sliding buckle is fixedly connected to a first connecting rod and a second connecting rod. One end of the first connecting rod is fixedly connected to the lower end of the TEC chip, and the second connecting rod is fixedly connected to the lower end of the activity plate. A connecting groove is provided inside the TEC chip. A connecting piece is provided inside the groove. Electrical connection can be achieved after the connecting groove is inserted into the connecting piece.

10. A cryogenic rapid and precise temperature control system based on cascade refrigeration and a TEC temperature control chip according to claim 9, characterized in that: The activity plate includes a side plate and a top plate. One end of the side plate is movably connected to the upper housing, and the other end of the side plate is movably connected to the top plate. The side plate is composed of two plate bodies sleeved together, and the plate bodies can slide relative to each other to adjust the length of the side plate. A limiting rod is fixedly connected to one side of the top plate, and the limiting rod is fixedly connected to the upper housing on one side. The limiting rod is also composed of two slidable and telescopic rod bodies. Through holes are provided in the areas where the first connecting rod passes through the inner wall of the plate evaporator.

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