Temperature control device and temperature control method of temperature and humidity calibration box

Abstract

The present invention provides a temperature control device for a temperature and humidity calibration box and a temperature control method thereof. The device includes a cold source system and a circulation system respectively connected to the primary side and the secondary side of the evaporator. The cold source system includes a compressor, an oil separator, a condenser, a liquid storage, a filter, a heat regenerator and a first flow regulating valve connected in sequence through pipelines; the circulation system includes a buffer tank, a surface cooler, a circulation pump, a first non-return valve and a pipeline heater connected in sequence through pipelines. The device and method have a wide temperature control range and a fast temperature control speed. The opening of the flow regulating valve can be adjusted according to the current working conditions to optimize the system performance; the temperature control accuracy is high. Due to the secondary heat exchange between the heat transfer medium and the air in the box, the influence of the temperature fluctuation of the heat transfer medium on the temperature in the box is reduced, so the temperature fluctuation degree in the box is ≤±0.01℃; the heat generated by the compressor itself is used as a heat source, the energy efficiency ratio is high, the power consumption is small, and the maximum power consumption can be saved by 50%.

Description

Technical Field

[0001] The invention relates to the technical field of temperature and humidity measurement, and in particular to a temperature control device and a temperature control method of a temperature and humidity calibration box. Background Art

[0002] Existing temperature and humidity calibration boxes usually use a constant temperature water tank to keep the circulating medium at a constant temperature, and realize the temperature control inside the box through secondary heat exchange. Since the compressor output cannot be adjusted according to the required temperature in the box, there is a lot of circulating medium in the constant temperature tank, which affects the temperature control speed and temperature control accuracy. The fluctuation can generally only reach ±0.1℃. In order to balance the cooling capacity, the heater power is large, the overall equipment power consumption is high, the energy efficiency ratio is low, and it also causes a huge waste of energy.

[0003] Chinese patent application CN 101118445 A discloses a temperature control method and structure for a temperature and humidity calibration box, including a working area in the calibration box, a constant temperature water tank installed in the calibration box, and a coil connected to the constant temperature water tank installed outside the working area. The temperature of the constant temperature water tank is first adjusted using a heater and a refrigeration compressor, and then the temperature of the working area is adjusted by circulating water between the coil and the constant temperature water tank. Since the device provided by this patent does not adjust the compressor output and uses a constant temperature water tank to control the temperature of the working area, the temperature control speed is slow and the equipment energy efficiency ratio is low, which also cannot meet the needs of current calibration operations.

[0004] Therefore, there is an urgent need for a temperature control device with a wide range, high precision, fast speed and low power consumption to meet the temperature control needs of the temperature and humidity calibration box. Summary of the invention

[0005] The purpose of the present invention is to overcome the deficiencies of the above-mentioned prior art and to provide a temperature control device and a temperature control method for a temperature and humidity calibration box. The device has a wide temperature control range, and the temperature inside the box reaches -40°C~80°C; the temperature control accuracy is high, and the temperature fluctuation inside the box is ≤±0.01°C; the temperature control speed is fast, and the temperature rise and fall time is half of that of a conventional calibration box; the device has a high energy efficiency ratio, and the temperature inside the box can be controlled at -40°C~60°C by relying solely on a compressor, which can save up to 50% of power consumption.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] The temperature control device of the temperature and humidity test box includes a cold source system and a circulation system respectively connected to the primary side and the secondary side of the evaporator.

[0008] The cold source system includes a compressor, an oil separator, a condenser, a liquid storage, a filter, a heat regenerator and a first flow regulating valve which are connected in sequence through pipelines, wherein the primary side inlet and outlet of the heat regenerator are respectively connected to the filter and the first flow regulating valve, the primary side inlet of the evaporator is connected to the outlet of the first flow regulating valve, and the primary side outlet is connected to the secondary side inlet of the heat regenerator; a heat dissipation fan is fixed at the condenser; and the secondary side outlet of the heat regenerator is connected to the air intake of the compressor.

[0009] The regenerator can increase the cooling capacity at low temperatures, reduce the cooling capacity at high temperatures, and widen the temperature control range without a heater; when cooling, the temperature of the gas coming out of the evaporator after heat exchange is low, and the temperature of the liquid after condensation in the condenser is high. The two complete heat exchange in the regenerator, lowering the liquid temperature and raising the gas temperature, avoiding the compressor from sucking in liquid and causing liquid hammer, while increasing the liquid supercooling, thereby increasing the cooling capacity and improving the cooling efficiency; when heating, the temperature of the gas coming out of the evaporator after heat exchange is high, and the temperature of the liquid after condensation in the condenser is low. The two complete heat exchange in the regenerator, raising the liquid temperature and lowering the gas temperature, avoiding the compressor from overheating the suction air and causing poor heat dissipation of the compressor motor, while increasing the liquid temperature, thereby reducing the cooling capacity and improving the heating efficiency.

[0010] The circulation system includes a buffer tank, a surface cooler, a circulation pump, a first non-return valve and a pipe heater which are connected in sequence through pipelines, wherein the secondary side inlet end of the evaporator is connected to the outlet end of the pipe heater, and the secondary side outlet end is connected to the inlet end of the buffer tank, and the surface cooler is arranged inside the temperature and humidity calibration box to control the temperature inside the temperature and humidity calibration box; the buffer tank can effectively perform secondary mixing of the heat transfer medium and also stabilize the flow rate of the heat transfer medium; the circulation system adopts the form of a pipe heater, which has a compact structure, occupies a small space, and has a small amount of heat transfer medium filling. It can maximize the heat exchange speed of the heat transfer medium and make the temperature of the heat transfer medium reach the required value in the shortest time to meet the temperature control requirements in the box, thereby achieving the purpose of rapid temperature control.

[0011] The circulation system drives the heat transfer medium through the circulation pump, which is first heated by the pipe heater, and then enters the surface cooler to exchange heat with the air in the temperature and humidity calibration box after heat exchange on the secondary side of the evaporator. A buffer tank is set at the outlet of the secondary side of the evaporator to buffer the temperature fluctuation caused by the turbulence of the heat transfer medium.

[0012] A second flow regulating valve and a third flow regulating valve are also connected to the cold source system. The inlet end of the second flow regulating valve is connected to the pipeline between the oil separator and the condenser, and the outlet end is connected to the pipeline between the evaporator and the first flow regulating valve; the inlet end of the third flow regulating valve is connected to the pipeline between the filter and the regenerator, and the outlet end is connected to the pipeline between the regenerator and the compressor; the third flow regulating valve can reduce the suction temperature of the compressor to avoid thermal protection and shortening of the life of the compressor due to excessively high temperature of the inhaled gas when high temperature is controlled.

[0013] An expansion water tank is also connected between the surface cooler and the circulation pump. The bottom of the expansion water tank is connected to the inlet end of the circulation pump, and the top is connected to the outlet end of the surface cooler. The top of the expansion water tank is also provided with an exhaust port to facilitate the discharge of gas inside the device pipeline. By setting up the expansion water tank, the medium involved in heat exchange in the circulation system can be effectively reduced, thereby improving the heating and cooling speed. The expansion water tank is small in size and flexible in installation, which can save space occupied by the device.

[0014] The circulation system is also connected to a fluid replenishment unit, which includes a fluid replenishment tank, a fluid replenishment pump and a second one-way valve. The top of the fluid replenishment tank is provided with a fluid filling port, and the bottom is connected to the inlet of the fluid replenishment pump. The outlet of the fluid replenishment pump is connected to the inlet of the second one-way valve, and the outlet of the second one-way valve is connected to the pipeline between the first one-way valve and the pipeline heater.

[0015] A high liquid level switch and a first low liquid level switch are fixed on the inner wall of the expansion water tank, and the volume of the heat transfer medium injected into the system is accurately controlled by the two liquid level switches; a second low liquid level switch is fixed on the inner wall of the liquid replenishment tank.

[0016] The primary side outlet end of the evaporator is fixedly connected to a first temperature sensor and a pressure sensor; the outlet end of the buffer tank is connected to a second temperature sensor; a third temperature sensor and a circulating fan for mixing the internal temperature are fixed in the temperature and humidity calibration box; the outlet end of the compressor is connected to a fourth temperature sensor; the temperature and pressure states of various points inside the device are monitored in real time by using the temperature sensors and pressure sensors, so as to facilitate the regulation and control of each valve.

[0017] The temperature control device is also provided with a controller, which is connected to various electrical components in the temperature control device. The controller is a PLC, a control circuit board or other device capable of realizing a control function.

[0018] The rehydration pump is a high-pressure pump, and the working pressure is higher than the working pressure of the circulation pump, so as to ensure that the circulation system can perform rehydration operation in real time when the circulation system is in operation.

[0019] When the circulation system is not full of liquid, the heat transfer medium enters the water suction port of the circulation pump from the expansion water tank and is driven by the circulation pump to enter the circulation system; when adding liquid, the medium is added to the liquid replenishing tank. After it is full, the liquid replenishing pump is turned on. The liquid replenishing pump enters the circulation system through the second one-way valve. The medium entering the device squeezes the air in the device into the expansion water tank and then discharges it, ensuring that the device is in a full liquid state. The medium that fills the device enters the expansion water tank, and the liquid addition is stopped when the liquid level in the expansion water tank reaches the high liquid level switch; when the expansion water tank reaches the low liquid level switch, the liquid replenishing pump is turned on to inject the medium into the device, ensuring that there is enough circulating medium in the device; the second one-way valve in the circulation system ensures that the medium entering the device fills the device along the direction of the circulation pump outlet, preventing backflow from directly pouring into the expansion water tank, causing the device to reach the high liquid level of the expansion water tank before it is full and stop adding liquid.

[0020] The temperature control method of the temperature control device of the temperature and humidity calibration box includes a rapid temperature rise and fall stage and a constant temperature stage;

[0021] 1). Rapid temperature rise and fall stage,

[0022] When the temperature of the temperature and humidity test box needs to be quickly lowered, the second flow regulating valve is closed, and the controller measures the temperature and pressure values ​​through the first temperature sensor and the pressure sensor, calculates the superheat, and then adjusts the first flow regulating valve to the required opening until the temperature in the temperature and humidity test box reaches the set value;

[0023] When the temperature of the temperature and humidity calibration box needs to be raised quickly, close the first flow regulating valve, adjust the second flow regulating valve to the maximum opening, and turn on the pipe heater until the temperature in the temperature and humidity calibration box reaches the set value.

[0024] 2). Constant temperature stage,

[0025] When the temperature and humidity calibration box is kept at a constant temperature, the first flow regulating valve is adjusted to the opening corresponding to the required temperature in the box, and the controller calculates and controls the second flow regulating valve to be adjusted to the required opening to achieve constant temperature; when the required temperature in the box exceeds the adjustment range of the second flow regulating valve, the opening of the second flow regulating valve is adjusted to the maximum, and then the temperature is kept constant by adjusting the output of the pipeline heater.

[0026] When the required temperature in the temperature and humidity calibration box is ≤60℃, the controller calculates the required temperature of the heat transfer medium according to the set temperature in the box, and then calculates the required opening of the second flow control valve according to the temperature of the heat transfer medium. The temperature in the box is indirectly controlled by adjusting the opening of the second flow control valve. The first flow control valve is first adjusted to the opening corresponding to the current temperature, and then fine-tuned according to the opening of the second flow control valve, so that the opening of the second flow control valve is maintained between 25% and 85% to obtain the best temperature control effect;

[0027] When the required temperature in the temperature and humidity calibration box is greater than 60°C, the controller calculates the required heat transfer medium temperature according to the set box temperature, adjusts the opening of the first flow regulating valve to 1%, and adjusts the opening of the second flow regulating valve to 100% to reduce the cooling capacity to the minimum, and then calculates the required output of the pipe heater according to the heat transfer medium temperature through the controller, and indirectly controls the box temperature by adjusting the output of the pipe heater.

[0028] All components used in the present invention are existing components commonly used in the industry and will not be described in detail here.

[0029] The beneficial effects of the present invention are:

[0030] 1). The compressor has a wide temperature control range. Taking R404A refrigerant as the benchmark, the boiling point is -46.22℃ at 0MPa pressure. When the second flow regulating valve is closed and the first flow regulating valve is adjusted to the corresponding opening of the current working condition, the temperature of the heat transfer medium can be reduced to -43℃ and the temperature inside the box can reach -40℃. The exhaust temperature of the compressor is 70~80℃. When the opening of the first flow regulating valve is adjusted to the minimum and the opening of the second flow regulating valve is adjusted to the maximum, the temperature of the heat transfer medium can be raised to 33℃ and the temperature inside the box to 30℃, that is, the temperature range inside the box is -40~30℃. With the assistance of the regenerator, the temperature inside the box can be expanded to -40℃~60℃. The heater is used to assist in temperature control only when the temperature is above 60℃.

[0031] 2). The temperature rise and fall speed is fast, and the flow control valve opening can be adjusted according to the current working conditions to optimize the system performance. The overall speed is increased by 10%~50% compared with the traditional method (capillary tube or thermal expansion valve);

[0032] 3). The temperature control accuracy is high, the flow control valve has a smooth adjustment process, and can achieve stepless adjustment, so that the cold or heat output of the cold source system is relatively balanced with the heat generated by the water pump and the heat dissipation of the box, so that the temperature fluctuation of the heat transfer medium reaches ±0.01℃. Due to the secondary heat exchange between the heat transfer medium and the air in the box, the influence of the temperature fluctuation of the heat transfer medium on the temperature in the box is reduced, so the temperature fluctuation in the box is ≤±0.01℃;

[0033] 4). High energy efficiency ratio. Compared with the method of balancing the heater and cooling capacity, using the heat generated by the compressor itself as the heat source can save up to 50% of electricity consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 is a schematic diagram of the temperature control device;

[0035] Among them, 1. compressor; 2. oil separator; 3. condenser; 4. liquid storage tank; 5. filter; 6. regenerator; 7. first flow regulating valve; 8. evaporator; 9. second flow regulating valve; 10. third flow regulating valve; 11. cooling fan; 12. circulating pump; 13. first non-return valve; 14. pipeline heater; 15. buffer tank; 16. surface cooler; 17. circulating fan; 18. expansion tank; 19. first low liquid level switch; 20. high liquid level switch; 21. second non-return valve; 22. replenishing pump; 23. replenishing tank; 24. second low liquid level switch; 25. first temperature sensor; 26. pressure sensor; 27. fourth temperature sensor; 28. second temperature sensor; 29. ​​third temperature sensor; 30. temperature and humidity calibration box. DETAILED DESCRIPTION

[0036] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0037] The structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention, so they have no substantial technical significance. Any modification of the structure, change of the proportional relationship or adjustment of the size, without affecting the effects and purposes that can be achieved by the present invention, should still fall within the scope of the technical contents disclosed by the present invention. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and "one" quoted in this specification are only for the convenience of description, and are not used to limit the scope of the implementation of the present invention. The change or adjustment of their relative relationship should also be regarded as the scope of the implementation of the present invention without substantially changing the technical contents.

[0038] like Figure 1 As shown, the temperature control device of the temperature and humidity calibration box includes a cold source system and a circulation system respectively connected to the primary side and the secondary side of the evaporator 8.

[0039] The cold source system includes a compressor 1, an oil separator 2, a condenser 3, a liquid storage device 4, a filter 5, a regenerator 6 and a first flow regulating valve 7 which are connected in sequence through pipelines, wherein the primary side inlet and outlet of the regenerator 6 are respectively connected to the filter 5 and the first flow regulating valve 7, the primary side inlet of the evaporator 8 is connected to the outlet of the first flow regulating valve 7, and the primary side outlet is connected to the secondary side inlet of the regenerator 6; a heat dissipation fan 11 is fixed at the condenser 3; the secondary side outlet of the regenerator 6 is connected to the air intake of the compressor 1; the regenerator 6 can increase the cooling capacity at low temperatures, reduce the cooling capacity at high temperatures, and broaden the temperature control without a heater Range; a second flow regulating valve 9 and a third flow regulating valve 10 are also connected to the cold source system, the inlet end of the second flow regulating valve 9 is connected to the pipeline between the oil separator 2 and the condenser 3 (the inlet end is connected to the inlet end of the condenser 3), and the outlet end is connected to the pipeline between the evaporator 8 and the first flow regulating valve 7; the inlet end of the third flow regulating valve 10 is connected to the pipeline between the filter 5 and the regenerator 6, and the outlet end is connected to the pipeline between the regenerator 6 and the compressor 1; the third flow regulating valve 10 can reduce the suction temperature of the compressor 1 to avoid thermal protection and shortening of the life of the compressor 1 due to excessively high temperature of the inhaled gas when high temperature is controlled.

[0040] The circulation system includes a buffer tank 15, a surface cooler 16, a circulation pump 12, a first non-return valve 13 and a pipe heater 14 which are connected in sequence through pipelines, wherein the secondary side inlet end of the evaporator 8 is connected to the outlet end of the pipe heater 14, and the secondary side outlet end is connected to the inlet end of the buffer tank 15, and the surface cooler 16 is arranged inside the temperature and humidity calibration box 30 to control the temperature inside the temperature and humidity calibration box 30; the buffer tank 15 can effectively perform secondary mixing of the heat transfer medium and also stabilize the flow rate of the heat transfer medium; the circulation system adopts the form of a pipe heater 14, which has a compact structure, occupies a small space, and has a small amount of heat transfer medium filling, and can maximize the heat exchange speed of the heat transfer medium, so that the temperature of the heat transfer medium reaches the required value in the shortest time to meet the temperature control requirements in the box, thereby achieving the purpose of rapid temperature control. An expansion water tank 18 is also connected between the cooler 16 and the circulation pump 12. The bottom of the expansion water tank 18 is connected to the inlet end of the circulation pump 12, and the top is connected to the outlet end of the cooler 16. The top of the expansion water tank 18 is also provided with an exhaust port to facilitate the discharge of gas inside the device pipeline. The expansion water tank 18 can effectively reduce the medium involved in heat exchange in the circulation system, thereby increasing the heating and cooling speed. The expansion water tank 18 is small in size and flexible in installation, which can save space occupied by the device. A high liquid level switch 20 and a first low liquid level switch 19 are fixed on the inner wall of the expansion water tank 18. The two liquid level switches are used to accurately control the volume of the heat transfer medium injected into the system. A second low liquid level switch 24 is fixed on the inner wall of the liquid replenishment tank 23.

[0041] A rehydration unit is also connected to the circulation system, and the rehydration unit includes a rehydration tank 23, a rehydration pump 22, and a second one-way valve 21. The top of the rehydration tank 23 is provided with a liquid filling port, and the bottom is connected to the inlet of the rehydration pump 22. The outlet of the rehydration pump 22 is connected to the inlet of the second one-way valve 21, and the outlet of the second one-way valve 21 is connected to the pipeline between the first one-way valve 13 and the pipeline heater 14. The rehydration pump 22 is a high-pressure pump, and the pressure during operation is higher than the working pressure of the circulation pump 12, so as to ensure that the circulation system can perform rehydration operation in real time when in operation.

[0042] A first temperature sensor 25 and a pressure sensor 26 are fixedly connected to the primary side outlet of the evaporator 8; a second temperature sensor 28 is connected to the outlet of the buffer tank 15; a third temperature sensor 29 and a circulating fan 17 for mixing the internal temperature are fixed in the temperature and humidity calibration box 30; a fourth temperature sensor 27 is connected to the outlet of the compressor 1; the temperature sensors and pressure sensors 26 are used to monitor the temperature and pressure status of each point inside the device in real time, so as to facilitate the regulation and control of each valve.

[0043] A controller is also provided in the temperature control device, and the controller is connected to various electrical components in the temperature control device. The controller is a PLC, a control circuit board or other device capable of realizing control functions.

[0044] The first, second and third flow regulating valves can use solenoid valves, electronic expansion valves or other electric valves that can achieve flow control.

[0045] The present invention also provides a temperature control method for a temperature and humidity calibration box temperature control device, comprising a rapid temperature rise and fall stage and a constant temperature stage;

[0046] 1). Rapid temperature rise and fall stage,

[0047] When the temperature of the temperature and humidity test box needs to be quickly lowered, the second flow regulating valve 9 is closed, and the controller measures the temperature and pressure values ​​through the first temperature sensor 25 and the pressure sensor 26, calculates the superheat, and then adjusts the first flow regulating valve 7 to the required opening until the temperature in the temperature and humidity test box reaches the set value;

[0048] When the temperature of the temperature and humidity test box needs to be raised quickly, the first flow regulating valve 7 is closed, the second flow regulating valve 9 is adjusted to the maximum opening, and the pipeline heater 14 is turned on until the temperature in the temperature and humidity test box reaches the set value.

[0049] 2). Constant temperature stage,

[0050] When the temperature and humidity calibration box requires a constant temperature, the first flow regulating valve 7 is adjusted to the opening corresponding to the required temperature in the box, and the controller calculates and controls the second flow regulating valve 9 to be adjusted to the required opening to achieve constant temperature; when the required temperature in the box exceeds the adjustment range of the second flow regulating valve 9, the opening of the second flow regulating valve 9 is adjusted to the maximum, and the temperature is achieved by adjusting the output of the pipe heater 14.

[0051] When the required temperature in the temperature and humidity calibration box is ≤60°C, the controller calculates the required temperature of the heat transfer medium according to the set temperature in the box, and then calculates the required opening of the second flow regulating valve 9 according to the temperature of the heat transfer medium. The temperature in the box is indirectly controlled by adjusting the opening of the second flow regulating valve 9. The first flow regulating valve 7 is first adjusted to the opening corresponding to the current temperature, and then fine-tuned according to the opening of the second flow regulating valve 9, so that the opening of the second flow regulating valve 9 is maintained between 25% and 85% to obtain the best temperature control effect;

[0052] When the required temperature in the temperature and humidity calibration box is greater than 60°C, the controller calculates the required heat transfer medium temperature according to the set box temperature, adjusts the opening of the first flow regulating valve 7 to 1%, and adjusts the opening of the second flow regulating valve 9 to 100% to reduce the cooling capacity to the minimum, and then calculates the required output of the pipe heater 14 according to the heat transfer medium temperature through the controller, and indirectly controls the box temperature by adjusting the output of the pipe heater 14.

[0053] Although the above describes the specific implementation mode of the present invention in conjunction with the accompanying drawings, it is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art on the basis of the technical solution of the present invention without creative work are still within the scope of protection of the present invention.

Claims

1. A temperature control method for a temperature and humidity calibration box temperature control device, characterized in that: The temperature control device of the temperature and humidity test box includes a cold source system and a circulation system respectively connected to the primary side and the secondary side of the evaporator. The cold source system comprises a compressor, an oil separator, a condenser, a liquid storage, a filter, a regenerator and a first flow regulating valve which are sequentially connected through pipelines, wherein the primary side inlet and outlet of the regenerator are respectively connected to the filter and the first flow regulating valve, the primary side inlet of the evaporator is connected to the outlet of the first flow regulating valve, and the primary side outlet is connected to the secondary side inlet of the regenerator; a heat dissipation fan is fixed at the condenser; and the secondary side outlet of the regenerator is connected to the air intake of the compressor; The circulation system comprises a buffer tank, a surface cooler, a circulation pump, a first check valve and a pipeline heater which are sequentially connected through pipelines, wherein the secondary side inlet end of the evaporator is connected to the outlet end of the pipeline heater, and the secondary side outlet end is connected to the inlet end of the buffer tank, and the surface cooler is arranged inside the temperature and humidity test box to control the temperature inside the temperature and humidity test box; The cold source system is also connected to a second flow regulating valve and a third flow regulating valve, wherein the inlet end of the second flow regulating valve is connected to the pipeline between the oil separator and the condenser, and the outlet end is connected to the pipeline between the evaporator and the first flow regulating valve; the inlet end of the third flow regulating valve is connected to the pipeline between the filter and the regenerator, and the outlet end is connected to the pipeline between the regenerator and the compressor; The temperature control method includes a rapid temperature rise and fall stage and a constant temperature stage: 1). Rapid temperature rise and fall stage, When the temperature of the temperature and humidity test box needs to be quickly lowered, the second flow regulating valve is closed, and the controller measures the temperature and pressure values ​​through the temperature sensor and the pressure sensor, calculates the superheat, and then adjusts the first flow regulating valve to the required opening until the temperature in the temperature and humidity test box reaches the set value; When the temperature of the temperature and humidity calibration box needs to be raised quickly, close the first flow regulating valve, adjust the second flow regulating valve to the maximum opening, and turn on the pipe heater until the temperature in the temperature and humidity calibration box reaches the set value; 2). Constant temperature stage, When the temperature and humidity calibration box requires a constant temperature, the first flow regulating valve is adjusted to the opening corresponding to the required temperature in the box, and the controller calculates and controls the second flow regulating valve to be adjusted to the required opening to achieve constant temperature; when the required temperature in the box exceeds the adjustment range of the second flow regulating valve, the opening of the second flow regulating valve is adjusted to the maximum, and the temperature is achieved by adjusting the output of the pipe heater.

2. The temperature control method of the temperature and humidity calibration box temperature control device as claimed in claim 1, characterized in that: An expansion water tank is also connected between the surface cooler and the circulation pump. The bottom of the expansion water tank is connected to the inlet end of the circulation pump, and the top end is connected to the outlet end of the surface cooler. An exhaust port is also opened at the top end of the expansion water tank.

3. The temperature control method of the temperature and humidity calibration box temperature control device as claimed in claim 1, characterized in that: The circulation system is also connected to a fluid replenishment unit, which includes a fluid replenishment tank, a fluid replenishment pump and a second one-way valve. The top of the fluid replenishment tank is provided with a fluid filling port, and the bottom is connected to the inlet of the fluid replenishment pump. The outlet of the fluid replenishment pump is connected to the inlet of the second one-way valve, and the outlet of the second one-way valve is connected to the pipeline between the first one-way valve and the pipeline heater.

4. The temperature control method of the temperature control device of the temperature and humidity calibration box according to claim 2 or 3, characterized in that: A high liquid level switch and a first low liquid level switch are fixed on the inner wall of the expansion water tank; a second low liquid level switch is fixed on the inner wall of the liquid replenishing tank.

5. The temperature control method of the temperature and humidity calibration box temperature control device as claimed in claim 1, characterized in that: The primary side outlet of the evaporator is fixedly connected to a first temperature sensor and a pressure sensor; the outlet of the buffer tank is connected to a second temperature sensor; a third temperature sensor and a circulating fan for mixing the internal temperature are fixed in the temperature and humidity calibration box; and the outlet of the compressor is connected to a fourth temperature sensor.

6. The temperature control method of the temperature and humidity calibration box temperature control device as claimed in claim 1, characterized in that: The temperature control device is also provided with a controller, and the controller is connected to various electrical components in the temperature control device.

7. The temperature control method of the temperature and humidity calibration box temperature control device as claimed in claim 3, characterized in that: The infusion pump is a high-pressure pump, and the pressure during operation is higher than the operating pressure of the circulation pump.

Images