A high and low temperature test chamber system and its control method

Abstract

The present invention discloses a high and low temperature test chamber system and its control method, which includes performing heat exchange on the low-temperature and low-pressure refrigerant that has released heat in the high-temperature test mechanism and the high-temperature and high-pressure refrigerant just discharged from the compressor in the low-temperature test mechanism on a heat exchanger, so that the temperature of the low-temperature and low-pressure refrigerant in the high-temperature test mechanism is increased and then enters the next compression cycle, increasing the heat of the next cycle. The high-temperature and high-pressure refrigerant in the low-temperature test mechanism is cooled by the heat exchanger and then forms a lower temperature than the refrigerant that has not undergone heat exchange through an expansion valve. Through the above process, the high-temperature test mechanism can reach a higher temperature, the low-temperature test mechanism can reach a lower temperature, and the heat of the two mechanism components is fully utilized. By making full use of the air energy principle, the hot and cold experiments are carried out simultaneously, the detection time is improved, and by using the air energy principle, heat is obtained from the air, and the energy efficiency is higher than that of traditional electric heating.

Description

Technical Field

[0001] The present invention relates to the field of high and low temperature testing, and particularly relates to a high and low temperature test chamber system and a control method thereof. Background Art

[0002] With the improvement of China's comprehensive national strength, the quality requirements for products are getting higher and higher, which means that the requirements for product testing equipment are also getting higher and higher. Existing industrial products need high and low temperature quality tests. Traditional testing equipment mainly adds electric heating elements in a fixed space to heat the space to form a high temperature space, so that the product is heated. The energy efficiency ratio is about 0.98 at most. The energy efficiency ratio of an air energy test chamber can be as high as 3.0. When ultra-low temperature is required, a compressor is needed for refrigeration. However, the low temperature environment temperature and efficiency that the compressor can create do not meet the specified requirements. When the product needs to do ultra-low temperature experiments, it is very difficult for general refrigeration equipment to reach this temperature. For low temperature experiments on small products, it will cause huge energy consumption. Summary of the Invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art. For this purpose, the present invention provides a control method for a high and low temperature test chamber system, which adopts a cascade heating system and has the advantages of high energy utilization efficiency, fast heating and cooling rates, and the ability to reach lower temperatures.

[0004] A control method for a high and low temperature test chamber system according to an embodiment of the first aspect of the present invention is applied to a high and low temperature test chamber system. The high and low temperature test chamber system includes: a high temperature test mechanism, the high temperature test mechanism includes a first compressor, a first condenser, a high temperature chamber body, and a first expansion valve connected in sequence, and a first fan is further provided and connected to the first condenser, and an electric heating element is provided in the high temperature chamber body; a low temperature test mechanism, the low temperature test mechanism includes a second compressor, a second condenser, a low temperature chamber body, and a second expansion valve connected in sequence, and a second fan is further provided and connected to the second condenser; a heat exchanger, the heat exchanger is respectively connected to the high temperature test mechanism and the low temperature test mechanism, and the heat exchanger is used for heat exchange between the high temperature test mechanism and the low temperature test mechanism; a temperature adjustment mechanism, the temperature adjustment mechanism includes a third fan, a third condenser, a fourth fan, a fourth condenser, a fifth condenser, and a fifth fan. The third fan and the third condenser are connected in parallel on the first condenser and form a high temperature chamber body temperature adjustment unit. The fourth fan and the fourth condenser are connected in parallel on the pipeline of the high temperature test mechanism on the heat exchanger to form a heat exchanger high temperature adjustment unit. The fifth fan and the fifth condenser are connected in parallel on the pipeline of the low temperature test mechanism on the heat exchanger to form a heat exchanger low temperature adjustment unit. The temperature adjustment mechanism is further provided with a solenoid valve. A first solenoid valve and a third solenoid valve are provided at the parallel connection of the first condenser and the third condenser for pipeline adjustment of the high temperature chamber body temperature adjustment unit. A fourth solenoid valve is further provided at the parallel connection of the fourth condenser for pipeline adjustment of the heat exchanger low temperature adjustment unit. A fifth solenoid valve and a second solenoid valve are provided at the parallel connection of the fifth condenser and the heat exchanger;

[0005] The control method includes the following steps:

[0006] The first compressor starts, and the refrigerant reaches the first solenoid valve from the exhaust port of the first compressor. The first fan starts, the first solenoid valve opens, and the third solenoid valve closes. The refrigerant is transported to the first condenser for heat exchange through the first fan; the normal-temperature high-pressure refrigerant becomes low-pressure low-temperature refrigerant after passing through the first expansion valve. The second solenoid valve is in the closed state. The low-pressure low-temperature refrigerant reaches the heat exchanger for heat exchange and then returns to the first compressor for re-compression; the second compressor starts simultaneously, the second solenoid valve opens, and the fifth solenoid valve closes. The refrigerant reaches the heat exchanger from the exhaust port of the second compressor, and the second fan starts; the third solenoid valve is in the closed state according to the system instruction, and the heat exchanger exchanges the high-temperature high-pressure refrigerant into low-temperature high-pressure refrigerant; the refrigerant then becomes ultra-low-temperature low-pressure refrigerant after passing through the second expansion valve and reaches the second condenser, and the refrigerant is heat-exchanged through the second fan, and the temperature of the low-temperature box decreases; the refrigerant is then inhaled into the second compressor through the pipeline for re-compression; wherein, when the temperature of the high-temperature box reaches the set temperature and the set temperature of the low-temperature box has not reached yet, the following steps are included: the first compressor keeps running, the third solenoid valve opens, the first solenoid valve closes, and the high-temperature box temperature regulation unit starts to cool the refrigerant passing through the third condenser; the second compressor keeps running, the second solenoid valve opens, and the fifth solenoid valve closes; when the set target is reached, the first compressor and the second compressor stop running simultaneously, and the first fan and the second fan keep running.

[0007] According to some embodiments of the present invention, when the temperature of the high-temperature box does not reach the set temperature and the temperature of the low-temperature box reaches the set temperature, the first compressor and the second compressor remain on standby, and the first fan and the second fan keep running; the heating element starts, and adjusts the heating power according to the temperature detection feedback in the system.

[0008] According to some embodiments of the present invention, when conducting a low-temperature experiment alone and the temperature of the low-temperature box is greater than or equal to -20 °C, the second solenoid valve closes, the fifth solenoid valve opens, the first compressor shuts down, the second compressor keeps working, and the second fan keeps working. When the low-temperature box reaches the specified temperature, the second compressor stops running.

[0009] According to some embodiments of the present invention, when conducting a low-temperature experiment alone and the temperature of the low-temperature box is less than or equal to -20 °C, the fifth solenoid valve closes, the second solenoid valve opens, the second compressor keeps running, and the low-temperature regulation unit of the heat exchanger keeps running; the third solenoid valve opens, the first solenoid valve closes, the high-temperature box temperature regulation unit starts, and the first compressor keeps running; when the low-temperature box reaches the specified temperature, the first compressor and the second compressor shut down.

[0010] According to some embodiments of the present invention, when conducting a high-temperature experiment alone and the temperature of the high-temperature chamber is less than or equal to 60 degrees Celsius, the third solenoid valve is closed, the first solenoid valve and the fourth solenoid valve are opened, the first fan and the high-temperature regulation unit of the heat exchanger remain operating, and the first compressor remains operating; when the high-temperature chamber reaches the specified temperature, the first compressor stops operating.

[0011] According to some embodiments of the present invention, when conducting a high-temperature experiment alone and the temperature of the high-temperature chamber is greater than or equal to 60 degrees Celsius, the third solenoid valve is closed, the first solenoid valve and the fourth solenoid valve are opened, the first fan and the high-temperature regulation unit of the heat exchanger remain operating, and the first compressor remains operating; when the high-temperature chamber reaches 60 degrees Celsius, the heating element is activated, and through the detection of the temperature of the high-temperature chamber by the system, the system then adjusts the heating power of the heating element to increase the temperature of the high-temperature chamber.

[0012] The control method of a high and low temperature test chamber system according to the above embodiments of the present invention has at least the following beneficial effects: it can effectively perform rapid adjustment under different temperatures and conditions, reduce energy consumption, enable the high-temperature chamber to reach a higher temperature and the low-temperature chamber to reach a lower temperature, and can operate in a single high-temperature or low-temperature system, improving the usability of the system.

[0013] Additional aspects and advantages of the present invention will be given in part in the following description, become apparent in part from the following description, or be learned through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The present invention will be further described below in conjunction with the drawings and embodiments, where:

[0015] Figure 1 is a schematic diagram of a high and low temperature test chamber system and its control method according to an embodiment of the present invention;

[0016] Figure 2 is Figure 1 a schematic diagram of the high-temperature experiment mechanism of a high and low temperature test chamber system and its control method shown;

[0017] Figure 3 is Figure 1 a schematic diagram of the low-temperature experiment mechanism of a high and low temperature test chamber system and its control method shown.

[0018] Reference numerals:

[0019] High-temperature experiment mechanism 100; Low-temperature experiment mechanism 200;

[0020] The first compressor 1; the third fan 2; the third condenser 3; the third solenoid valve 4; the first solenoid valve 5; the high-temperature box 6; the air outlet 7; the experimental box 8; the electric heating element 9; the first fan 10; the first condenser 11; the first expansion valve 12; the check valve 13; the fourth solenoid valve 14; the heat exchanger 15; the fourth condenser 16; the fourth fan 17;

[0021] The second compressor 20; the fifth fan 21; the fifth condenser 22; the fifth solenoid valve 23; the second solenoid valve 24; the second expansion valve 25; the low-temperature box 26; the second fan 27; the second condenser 28. Detailed implementation manners

[0022] The embodiments of the present invention will be described in detail below. The examples of the embodiments are shown in the drawings, in which the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are only used to explain the present invention and should not be construed as a limitation of the present invention.

[0023] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by terms such as up, down, front, back, left, right, etc. is based on the orientation or positional relationship shown in the drawings. It is 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 of the present invention.

[0024] In the description of the present invention, the meaning of "several" is one or more, the meaning of "multiple" is more than two, and understandings such as "greater than", "less than", "exceeding", etc. do not include the present number, and understandings such as "above", "below", "within", etc. include the present number. If there is a description of "first" and "second", it is only for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the sequence relationship of the indicated technical features.

[0025] In the description of the present invention, unless otherwise clearly defined, words such as "set", "installed", "connected", etc. should be understood in a broad sense, and those skilled in the art can reasonably determine the specific meanings of the above words in the present invention in combination with the specific content of the technical solution.

[0026] According to some embodiments of the present application, with reference to Figures 1 to 3As shown, when starting the experimental system, the high-temperature experimental mechanism 100 starts first, and the low-temperature experimental mechanism 200 starts with a delay. At this time, the first fan 10 and the third fan 2 start. After 1 minute, the first compressor 1 starts. 30 seconds before the first compressor 1 starts, the first solenoid valve 5 opens and the third solenoid valve 4 closes. The refrigerant reaches the first condenser 11 from the exhaust port of the first compressor 1. The high-temperature heat of the first condenser 11 is sent to the high-temperature box 6 by the first fan 10. Then, after throttling through the first expansion valve 12, it reaches the fourth solenoid valve 14. Then the refrigerant is divided into two paths and enters the heat exchanger 15 and the fourth evaporator; 3 minutes after the first compressor 1 starts, the low-temperature experimental mechanism 200 starts to start, the second fan 27 starts. After 1 minute, the second compressor 20 starts. 30 seconds before the second compressor 20 starts, the second solenoid valve 24 is opened and the fifth solenoid valve 23 is closed. The refrigerant reaches the heat exchanger 15 from the exhaust port of the second compressor 20. The high-temperature heat refrigerant exchanges heat with the low-pressure and low-temperature refrigerant in the high-temperature experimental mechanism 100 in the heat exchanger 15. After passing through the heat exchanger 15, the refrigerant of the high-temperature experimental mechanism 100 becomes high-temperature refrigerant and is compressed by the first compressor 1 again to obtain a large amount of high-temperature heat. The refrigerant of the low-temperature experimental mechanism 200 has a large degree of subcooling. After throttling, the evaporation temperature is extremely low. Therefore, an ultra-low temperature refrigerant is formed and transported to the second evaporator to absorb heat.

[0027] It should be noted that the high-temperature box 6 and the low-temperature box 26 are provided with a specially enlarged experimental box 8, and the experimental box 8 is provided with an exhaust port 7.

[0028] According to some embodiments of the present application, referring to Figures 1 to 3 As shown, when the temperature of the high-temperature box 6 exceeds the designed operating temperature of the machine, and the set temperature of the low-temperature box 26 has not reached yet; at this time, the first compressor 1 continues to run, the third solenoid valve 4 closes, and the first solenoid valve 5 opens. When the temperature of the high-temperature box 6 reaches the limit, the third solenoid valve 4 opens, the first solenoid valve 5 closes, and the third fan 2 starts. The third condenser 3 is used to ensure the stable operation of the machine. At this time, the electric heating element 9 is turned on. The system compares the difference between the actual temperature and the set target temperature and outputs the corresponding heat. When the actual temperature + 5 ≤ the target temperature, the main control detects once every 2 seconds, and the electric heating element 9 increases the power output at a speed of 5%. When the actual temperature ≥ the target temperature + 1, the electric heating element 9 stops outputting. When the temperature drops and the actual temperature + 2 ≤ the target temperature, the electric heating element 9 outputs the corresponding power at a speed of 1% to keep the temperature deviation within ±1. At this time, in the low-temperature zone system, the second solenoid valve 24 opens and the fifth solenoid valve 23 closes to maintain normal operation until the set target value is reached. The high-temperature box 6 and the low-temperature box 26 stop running and remain in the standby state. At this time, the first fan 10 and the second fan 27 continue to run.

[0029] According to some embodiments of the present application, referring to Figures 1 to 3As shown, when the temperature of the high-temperature chamber 6 reaches the set temperature and the set temperature of the low-temperature chamber 26 has not been reached yet, at this time, the first compressor 1 continues to operate, the third solenoid valve 4 is opened, the first solenoid valve 5 is closed, the third fan 2 is started, the third condenser 3 is used, and the machine maintains normal operation. For the low-temperature test mechanism 200, the second solenoid valve 24 is opened and the fifth solenoid valve 23 is closed to maintain normal operation until the set target value is reached. Then, the high-temperature zone and the low-temperature zone stop and enter the standby state. At this time, the first fan 10 and the second fan 27 continue to operate.

[0030] According to some embodiments of the present application, referring to Figures 1 to 3 As shown, when the temperature of the high-temperature chamber 6 has not reached the set temperature and the temperature of the low-temperature chamber 26 has reached the set temperature, at this time, the systems of the low-temperature zone and the high-temperature zone are in the standby state, and the first fan 10 and the second fan 27 continue to operate. At this time, the heating element 9 is started. When the actual temperature + 5 ≤ the target temperature, the main control detects once every 2 seconds, and the heating element 9 increases the power output at a rate of 5%. When the actual temperature ≥ the target temperature + 1, the heating element 9 stops outputting. When the temperature drops and the actual temperature + 2 ≤ the target temperature, the heating element 9 outputs correspondingly at a rate of 1% to keep the temperature deviation within ±1.

[0031] According to some embodiments of the present application, referring to Figures 1 to 3 As shown, when conducting a low-temperature test alone and the target temperature ≥ -20°C, the second solenoid valve 24 is closed, the fifth solenoid valve 23 is opened, the second compressor 20 is started, and the fifth fan 21 is started. At this time, the high-temperature test mechanism 100 does not operate until the set temperature is reached, and then it enters the standby state. When the actual temperature ≥ the set temperature + 2°C, the low-temperature test mechanism 200 is started again; when conducting a low-temperature test alone and the target temperature ≤ -20°C, the fifth solenoid valve 23 is closed, the second solenoid valve 24 is opened, the second compressor 20 is started. Until the temperature of the low-temperature chamber 26 reaches ≤ -18°C, the third solenoid valve 4 is opened, the first solenoid valve 5 is closed, the third fan 2 is started, and the first compressor 1 is started to provide a better cooling effect for the low-temperature chamber 26, form a lower evaporation temperature, and achieve a lower temperature. Until the set temperature is reached, the high-temperature test mechanism 100 and the low-temperature test mechanism 200 enter the standby state. When the actual temperature ≥ the set temperature + 2°C, the high-temperature test mechanism 100 and the low-temperature test mechanism 200 are started again.

[0032] According to some embodiments of the present application, referring to Figures 1 to 3As shown, when conducting a high-temperature experiment alone and the target temperature ≤ 60°C, the third solenoid valve 4 is closed, the first solenoid valve 5 and the fourth solenoid valve 14 are opened, the first blower 10 and the fourth blower 17 are started, and then the first compressor 1 is started. After reaching the set temperature, it goes into standby. When the actual temperature ≥ set temperature - 3°C, the system starts again. When conducting a high-temperature experiment alone and the target temperature ≥ 60°C, the third solenoid valve 4 is closed, the first solenoid valve 5 and the fourth solenoid valve 14 are opened, the first blower 10 and the fourth blower 17 are started, and then the first compressor 1 is started. When the actual temperature in the high-temperature test chamber = 60°C, the electric heating element 9 is started. When the actual temperature + 5 ≤ target temperature, the main control checks the electric heating every 2 seconds and increases the power output at a rate of 5%. When the actual temperature ≥ target temperature + 1, the electric heating element 9 stops outputting. When the temperature drops and the actual temperature + 2 ≤ target temperature, the electric heating element 9 outputs power at a corresponding rate of 1% to keep the temperature deviation within ±1.

[0033] According to some embodiments of the present application, with reference to Figures 1 to 3 As shown, according to some embodiments of the present invention, check valves 13 are provided in the output pipelines of the third condenser 3, the fourth condenser 16, and the fifth condenser 22 before they are connected in parallel. The check valve 13 can prevent the refrigerant from flowing back through the pipeline from the heat exchanger 15 before reaching the heat exchanger 15, which may cause the refrigerant to exchange heat with the outside in the reverse direction through the condenser, weakening the function of the heat exchanger 15 and reducing the energy efficiency.

[0034] According to some embodiments of the present application, with reference to Figures 1 to 3 As shown, the high-temperature box body 6 and the low-temperature box body 26 are both annular air duct structures. The annular air duct can make the air form a cycle, keeping the temperature consistent throughout the box body, making the temperature of each part of the experimental product consistent, and ensuring the accuracy of the experimental results.

[0035] According to some embodiments of the present application, with reference to Figures 1 to 3 As shown, an experimental box body 8 is also provided on one side of the air outlet direction of the first blower 10 in the annular air duct. The diameter of the experimental box body 8 is larger than that of the air duct. The experimental box body 8 is a space for placing experimental products.

[0036] According to some embodiments of the present application, with reference to Figures 1 to 3 As shown, the experimental box body 8 is also provided with an air outlet 7. The air outlet 7 is used to discharge the air in the box body. Since some products may emit gases of other components due to high temperature, which may cause experimental errors, the air outlet 7 is added to discharge the air.

[0037] The above has described the embodiments of the present invention in detail with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those of ordinary skill in the art, various changes can be made without departing from the gist of the present invention.

[0038] The embodiments of the present invention have been described in detail above in conjunction with the accompanying drawings. However, the present invention is not limited to the above embodiments, and various changes can be made without departing from the spirit of the present invention within the scope of knowledge possessed by those of ordinary skill in the relevant art.

Claims

1. A control method for a high and low temperature test chamber, which is applied to a high and low temperature test chamber system. Characterized in that The high and low temperature test chamber system includes: a high temperature test mechanism, the high temperature test mechanism includes a first compressor, a first condenser, a high temperature chamber body, and a first expansion valve connected in sequence, and a first fan is also provided and connected to the first condenser, and an electric heating element is provided in the high temperature chamber body; a low temperature test mechanism, the low temperature test mechanism includes a second compressor, a second condenser, a low temperature chamber body, and a second expansion valve connected in sequence, and a second fan is also provided and connected to the second condenser; a heat exchanger, the heat exchanger is respectively connected to the high temperature test mechanism and the low temperature test mechanism, and the heat exchanger is used to perform heat exchange between the high temperature test mechanism and the low temperature test mechanism; a temperature adjustment mechanism, the temperature adjustment mechanism includes a third fan, a third condenser, a fourth fan, a fourth condenser, a fifth condenser and a fifth fan, the third fan and the third condenser are connected in parallel on the first condenser and form a high temperature chamber body temperature adjustment unit, the fourth fan and the fourth condenser are connected in parallel on the pipeline of the high temperature test mechanism on the heat exchanger to form a heat exchanger high temperature adjustment unit, and the fifth fan and the fifth condenser are connected in parallel on the pipeline of the low temperature test mechanism on the heat exchanger to form a heat exchanger low temperature adjustment unit; the temperature adjustment mechanism is also provided with a solenoid valve, and a first solenoid valve and a third solenoid valve are provided at the parallel connection of the first condenser and the third condenser for adjusting the pipeline of the high temperature chamber body temperature adjustment unit, and a fourth solenoid valve is also provided at the parallel connection of the fourth condenser for adjusting the pipeline of the heat exchanger low temperature adjustment unit, and a fifth solenoid valve and a second solenoid valve are provided at the parallel connection of the fifth condenser and the heat exchanger The control method includes the following steps: The first compressor starts, the refrigerant reaches the first solenoid valve from the exhaust port of the first compressor, the first fan starts, the first solenoid valve opens, the third solenoid valve closes, and the refrigerant is transported to the first condenser for heat exchange through the first fan; The normal temperature and high pressure refrigerant becomes a low pressure and low temperature refrigerant after passing through the first expansion valve, the second solenoid valve is in a closed state, the low pressure and low temperature refrigerant reaches the heat exchanger for heat exchange, and then returns to the first compressor for re-compression; The second compressor starts at the same time, the second solenoid valve opens, the fifth solenoid valve closes, the refrigerant reaches the heat exchanger from the exhaust port of the second compressor, and the second fan starts; The third solenoid valve is in a closed state according to the system instruction, and the heat exchanger exchanges the high temperature and high pressure refrigerant into a low temperature and high pressure refrigerant; The refrigerant then becomes an ultra-low temperature and low pressure refrigerant after passing through the second expansion valve and reaches the second condenser, and the refrigerant is heat-exchanged through the second fan, and the temperature of the low temperature chamber body decreases; The refrigerant is then sucked into the second compressor from the pipeline for re-compression; Among them, when the temperature of the high-temperature chamber reaches the set temperature while the set temperature of the low-temperature chamber has not reached yet, the following steps are included: the first compressor keeps running, the third solenoid valve opens, the first solenoid valve closes, and the high-temperature chamber temperature regulation unit starts to cool down the refrigerant passing through the third condenser; the second compressor keeps running, the second solenoid valve opens, and the fifth solenoid valve closes; when the set target is reached, the first compressor and the second compressor stop running simultaneously, and the first fan and the second fan keep running.

2. The control method of a high and low temperature test chamber according to claim 1, characterized in that when the temperature of the high-temperature chamber has not reached the set temperature and the temperature of the low-temperature chamber has reached the set temperature, the following steps are included: the first compressor and the second compressor remain on standby, and the first fan and the second fan keep running; the electric heating element starts, and adjusts the heating power according to the temperature detection feedback in the system.

3. The control method of a high and low temperature test chamber according to claim 1 or 2, characterized in that when conducting a low-temperature test alone and the temperature of the low-temperature chamber is greater than or equal to -20 °C, the following steps are included: the second solenoid valve closes, the fifth solenoid valve opens, the first compressor shuts down, the second compressor keeps working, the fifth fan keeps working, and when the low-temperature chamber reaches the specified temperature, the second compressor stops running.

4. The control method of a high and low temperature test chamber according to claim 1 or 2, characterized in that when conducting a low-temperature test alone and the temperature of the low-temperature chamber is less than or equal to -20 °C, the following steps are included: the fifth solenoid valve closes, the second solenoid valve opens, the second compressor keeps running, and the low-temperature heat exchanger regulation unit keeps running; the third solenoid valve opens, the first solenoid valve closes, the high-temperature chamber temperature regulation unit starts, and the first compressor keeps running; when the low-temperature chamber reaches the specified temperature, the first compressor and the second compressor shut down.

5. The control method of a high and low temperature test chamber according to claim 1 or 2, characterized in that when conducting a high-temperature test alone and the temperature of the high-temperature chamber is less than or equal to 60 °C, the following steps are included: the third solenoid valve closes, the first solenoid valve and the fourth solenoid valve open, the first fan and the high-temperature heat exchanger regulation unit keep running, and the first compressor keeps running; after the high-temperature chamber reaches the specified temperature, stop running the first compressor.

6. The control method of a high and low temperature test chamber according to claim 1 or 2, characterized in that when conducting a high-temperature test alone and the temperature of the high-temperature chamber is greater than or equal to 60 °C, the following steps are included: the third solenoid valve closes, the first solenoid valve and the fourth solenoid valve open, the first fan and the high-temperature heat exchanger regulation unit keep running, and the first compressor keeps running; When the high-temperature box reaches 60 degrees Celsius, the electric heating element starts. Through the detection of the temperature of the high-temperature box by the system, the system then adjusts the heating power of the electric heating element to increase the temperature of the high-temperature box.

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