A high and low temperature and low air pressure test chamber capable of achieving rapid heat exchange and automatic dehumidification

Abstract

The present invention discloses a high and low temperature and low air pressure test chamber capable of achieving rapid heat exchange and automatic dehumidification, which comprises a box body, and an atmospheric pressure heating and refrigeration system is arranged in the box body. The atmospheric pressure heating and refrigeration system includes a refrigeration unit. It is characterized in that a low air pressure rapid heat exchange device is arranged around a test piece in the box body. The low air pressure rapid heat exchange device includes a heat radiation plate, and coil type heating wires and refrigeration coils are uniformly arranged on the back surface of the heat radiation plate. The coil type heating wires and the refrigeration coils are arranged at intervals. A first branch pipe is branched from the refrigerant outlet pipeline of the refrigeration unit and is connected to the inlet end of the refrigeration coil, and the outlet end of the refrigeration coil is connected to the refrigerant circuit pipeline of the refrigeration unit. The present invention can achieve rapid heat transfer under a low air pressure state, with higher efficiency, less energy loss, faster temperature rise and fall time of the test piece, and shorter time for the temperature to reach a constant value.

Description

Technical Field

[0001] The present invention relates to a high and low temperature and low air pressure test chamber capable of achieving rapid heat exchange and automatic dehumidification, belonging to the field of test devices. Background Art

[0002] High and low temperature environmental test equipment is mainly used to simulate the extreme climates of high temperature or low temperature in the natural environment, and evaluate the performance of products under extreme conditions.

[0003] Under certain temperature conditions, such as -40°C or +100°C, the air in the test chamber is evacuated and the pressure is reduced. After the pressure reduction, the measured temperature value will change, and the lower the pressure, the greater the change. At normal pressure, forced convection (including a refrigeration evaporator, a heater, and a circulation fan) is used for heat exchange in the chamber to quickly and effectively bring the temperature of the test piece to the target value. However, when the pressure is below 4 kPa (the limit pressure of a general high and low temperature and low air pressure test chamber is 500 Pa or lower), the air is very thin, and forced convection loses its effect. Therefore, how to solve the problem of rapid heat transfer under low air pressure has become an issue that needs to be addressed.

[0004] When a low air pressure test chamber conducts a damp heat test under low air pressure, since the working chamber needs to maintain a low air pressure, the vacuum pump needs to run continuously to evacuate the working chamber. However, under damp heat conditions, the air humidity in the working chamber is high, and the air extracted by the vacuum pump has a high moisture content. The moisture enters the lubricating oil of the vacuum pump, resulting in a reduction in lubrication effect. After long-term operation, the vacuum pump is likely to be damaged. In the past, a drying filter was added in front of the vacuum pump, but the drying filter element needed to be replaced frequently, and it was difficult for customers to master the replacement time cycle, causing great inconvenience to customers. Therefore, there is an urgent need for a new drying treatment method to replace the previous one. Summary of the Invention

[0005] Aiming at the above technical problems, the purpose of the present invention is to provide a high and low temperature and low air pressure test chamber capable of achieving rapid heat exchange and automatic dehumidification, which has faster heat transfer and higher efficiency under low air pressure conditions, can achieve automatic control of dehumidification, does not require replacement of the drying filter element, and reduces the damage of the vacuum pump.

[0006] To achieve the above object, the technical solution of the present invention is as follows: A high and low temperature and low air pressure test chamber capable of achieving rapid heat exchange and automatic dehumidification, including a box body, an atmospheric pressure heating and refrigeration system is arranged in the box body, the atmospheric pressure heating and refrigeration system includes a refrigeration unit, and an evacuation pipe is arranged on the box body, and it is characterized in that: A low air pressure rapid heat exchange device is arranged around the test piece in the box body, the low air pressure rapid heat exchange device includes a heat radiation plate, and coiled heating wires and refrigeration coils are uniformly arranged on the back of the heat radiation plate, the coiled heating wires and the refrigeration coils are arranged at intervals, a first branch pipe is branched from the refrigerant outlet pipeline of the refrigeration unit and connected to the inlet end of the refrigeration coil, and the outlet end of the refrigeration coil is connected to the refrigerant circuit pipeline of the refrigeration unit;

[0007] The evacuation pipe is connected to the hot side inlet of the plate heat exchanger, the cold side outlet of the plate heat exchanger is connected to the vacuum pump, the cold side inlet of the plate heat exchanger is connected to a second branch pipe branched from the refrigerant outlet pipeline of the refrigeration unit, a refrigeration solenoid valve and a thermostatic expansion valve are arranged on the second branch pipe, the hot side outlet pipeline of the plate heat exchanger is connected to the refrigerant circuit pipeline of the refrigeration unit, an evaporation pressure regulating valve is arranged on the hot side outlet pipeline of the plate heat exchanger, and the bottom drain outlet of the plate heat exchanger is connected to a water collecting bucket.

[0008] Under low air pressure conditions, the test piece is heated by the coiled heating wires (the heat of the coiled heating wires is radiated to the test piece through the heat radiation plate), and the test piece is radiatively heated, so that the temperature of the test piece rises. Under the condition of the same heat density, the larger the radiation area of the coiled heating wires, the faster the radiative heat transfer, and the higher the efficiency. The refrigeration of the test piece is a reverse process. When the temperature of the test piece is high, heat radiation occurs outward, and the heat radiation plate now becomes a cold plate that receives heat (the refrigeration coil can take away the heat received on the plate), taking away the heat of the test piece and reducing the temperature of the test piece. Heating and refrigeration are used alternately. When the test piece needs to be heated, the heating wires work, radiatively heating the test piece to increase the temperature of the test piece, and the refrigeration stops working. When the test piece needs to be cooled, the refrigeration coil works, receives the radiative heat of the test piece, takes away the heat, and reduces the temperature of the test piece, and the heating wires stop working.

[0009] Under the condition of the same heat density, the larger the radiation (or radiation reception) area of the heating wires, the faster the radiative heat (or heat taken away) transfer, the better the radiation direction consistency, the smaller the loss, and the higher the efficiency.

[0010] Using the original refrigeration system of the low air pressure test chamber, a refrigeration bypass is branched out, and dehumidification is carried out by means of low temperature condensation. The dry air after the wet air is condensed and dehumidified enters the vacuum pump again, and the dehumidified water is collected through the water collecting bucket. This device can realize automatic control processing and does not require the replacement of consumables (dry filters) during use.

[0011] In the above solution: An automatic control valve is provided on the first branch pipe of the refrigerant outlet pipeline of the refrigeration unit. The coiled heating wire controls the automatic disconnection and connection of the power supply through an automatic control switch, facilitating the realization of automatic control.

[0012] In the above solution: Low-pressure rapid heat exchange devices are provided on at least three sides of the test piece.

[0013] In the above solution: The heat radiation plate is an aluminum alloy plate, which has good heat conduction and low cost.

[0014] In the above solution: A drain pipe is provided at the bottom of the water collecting bucket, and a drainage pump and a drainage valve are provided on the drain pipe.

[0015] In the above solution: The drainage valve is an automatic drainage solenoid valve. Condensate is discharged from the system through the drainage solenoid valve at regular intervals.

[0016] Compared with the prior art, the present invention has the following beneficial effects: The present invention can achieve rapid heat transfer under low-pressure conditions, with higher efficiency, less energy loss, faster temperature rise and fall time of the test piece, and shorter time for the temperature to reach a constant value. The dehumidification is carried out by a refrigeration condensation method, which can be recycled for a long time without the need to use consumables such as drying filters, reducing the processing cost. It can achieve full-automatic control without the need to regularly replace the drying filter. The full-automatic control can avoid damage to the vacuum pump caused by the user forgetting to replace the drying filter. Using the original refrigeration unit, the equipment investment is small. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a schematic structural diagram of the present invention.

[0018] Figure 2 is a schematic distribution diagram of the low-pressure rapid heat exchange device in the box body. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0019] The present invention will be further described below through embodiments in conjunction with the drawings:

[0020] Embodiment 1, as Figure 1 shown, the high and low temperature and low pressure test chamber capable of realizing rapid heat exchange and automatic dehumidification of the present invention is composed of a box body 1, a refrigeration unit 2, a low-pressure rapid heat exchange device 3, a plate heat exchanger 4, a vacuum pump 5, a refrigeration solenoid valve 6, a thermal expansion valve 7, an evaporation pressure regulating valve 8, a water collecting bucket 9, a drainage pump 10 and a drainage valve 11.

[0021] A box body door 101 is provided on one side of the box body 1, a vacuum extraction pipe 102 is provided on the box body 1, and a normal pressure heating and refrigeration system is provided on the side opposite to the box body door 101. The normal pressure heating and refrigeration system includes a heater 103, a refrigeration evaporator 104, a circulation fan and the refrigeration unit 2. This is the prior art and will not be elaborated here.

[0022] A low-pressure rapid heat exchange device 3 is added around the test piece in the box 1, and a low-pressure rapid heat exchange device 3 is set at least on three sides of the test piece. There is a gap between the low-pressure rapid heat exchange devices 3 on each side. In the figure, low-pressure rapid heat exchange devices 3 are set on three sides of the test piece, and three low-pressure rapid heat exchange devices 3 form a ]-shaped structure. The low-pressure rapid heat exchange device 3 includes a heat radiation plate 301, and the heat radiation plate 301 is an aluminum alloy plate with good thermal conductivity and low cost. Coil-type heating wires 302 and cooling coils 303 are evenly arranged on the back of the heat radiation plate 3. The coil-type heating wires 302 and the cooling coils 303 are arranged at intervals. The refrigerant outlet pipeline of the refrigeration unit 2 branches out a first branch pipe connected to one end of the cooling coil, and an automatic control valve 304 is set on the first branch pipe of the refrigerant outlet pipeline of the refrigeration unit. The other end of the cooling coil 303 is connected to the refrigerant circuit pipeline of the refrigeration unit. The coil-type heating wire is automatically disconnected and connected by controlling the power supply through an automatic control switch (not shown in the figure).

[0023] In order to realize automatic control of dehumidification, there is no need to replace the drying filter element, and the damage of the vacuum pump is reduced. The vacuum pipe 3 is connected to the hot side inlet of the plate heat exchanger 4, the cold side outlet of the plate heat exchanger 4 is connected to the vacuum pump 5, the cold side inlet of the plate heat exchanger 4 is connected to the second branch pipe branched from the refrigerant outlet pipeline of the refrigeration unit 2, and the second branch pipe is provided with a refrigeration solenoid valve 6 and a thermal expansion valve 7, the hot side outlet pipeline of the plate heat exchanger 4 is connected to the refrigerant circuit pipeline of the refrigeration unit 2, and the hot side outlet pipeline of the plate heat exchanger 4 is provided with an evaporation pressure regulating valve 8, and the bottom drain port of the plate heat exchanger 4 is connected to the water collecting bucket 9. A drain pipe is provided at the bottom of the water collecting bucket 9, and a drain pump 10 and a drain valve 11 are provided on the drain pipe. The drain valve 11 is an automatic drain solenoid valve, which can realize automatic control.

[0024] The present invention is not limited to the above-mentioned embodiments. Those skilled in the art will appreciate that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and purpose of the present invention. The scope of the present invention is defined by the claims and their equivalents.

Claims

1. A high and low temperature and low air pressure test chamber capable of realizing rapid heat exchange and automatic dehumidification, comprising a box body, an atmospheric pressure heating and refrigeration system is arranged in the box body, the atmospheric pressure heating and refrigeration system comprises a refrigeration unit, and a vacuum pumping pipe is arranged on the box body, and is characterized in that: A low-pressure rapid heat exchange device is arranged around the test piece in the box body. The low-pressure rapid heat exchange device includes a heat radiation plate. Coiled heating wires and refrigeration coils are evenly arranged on the back of the heat radiation plate. The coiled heating wires and the refrigeration coils are arranged at intervals. The refrigerant outlet pipeline of the refrigeration unit branches out a first branch pipe and is connected to the inlet end of the refrigeration coil. The outlet end of the refrigeration coil is connected to the refrigerant circuit pipeline of the refrigeration unit; The vacuum extraction pipe is connected to the hot-side inlet of the plate heat exchanger. The cold-side outlet of the plate heat exchanger is connected to the vacuum pump. The cold-side inlet of the plate heat exchanger is connected to a second branch pipe branched out from the refrigerant outlet pipeline of the refrigeration unit. A refrigeration solenoid valve and a thermostatic expansion valve are arranged on the second branch pipe. The hot-side outlet pipeline of the plate heat exchanger is connected to the refrigerant circuit pipeline of the refrigeration unit. An evaporation pressure regulating valve is arranged on the hot-side outlet pipeline of the plate heat exchanger. The bottom drain port of the plate heat exchanger is connected to a water collecting bucket; The heat radiation plate is an aluminum alloy plate.

2. The high and low temperature and low air pressure test chamber capable of realizing rapid heat exchange and automatic dehumidification according to claim 1, wherein: An automatic control valve is arranged on the first branch pipe of the refrigerant outlet pipeline of the refrigeration unit.

3. The high and low temperature and low air pressure test chamber capable of achieving rapid heat exchange and automatic dehumidification according to claim 2, characterized in that: The coiled heating wire controls the automatic disconnection and connection of the power supply through an automatic control switch.

4. The high and low temperature and low air pressure test chamber capable of achieving rapid heat exchange and automatic dehumidification according to any one of claims 1-3, characterized in that: Low-pressure rapid heat exchange devices are arranged on at least three sides of the test piece.

5. The high and low temperature and low air pressure test chamber capable of achieving rapid heat exchange and automatic dehumidification according to claim 1, wherein: A drain pipe is arranged at the bottom of the water collecting bucket. A drain pump and a drain valve are arranged on the drain pipe.

6. The high and low temperature and low air pressure test chamber capable of achieving rapid heat exchange and automatic dehumidification according to claim 5, wherein: The drain valve is an automatic drain solenoid valve.

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