A low-temperature test environment system suitable for closed laboratory benches

Abstract

The present invention belongs to the field of low-temperature test technology, and specifically relates to a low-temperature test environment piping system suitable for a closed test bench. The present invention includes an air intake duct, an exhaust duct, a heat exchanger, a test bench, and a booster fan; during external circulation, the inlet valve, the outlet valve, the lower air intake valve and the upper air intake valve of the test bench are opened, and under the action of the booster fan, the air pressure inside the test bench is balanced with the external air pressure, thereby achieving internal and external air convection; during internal circulation, the inlet valve and the outlet valve are closed, and the lower air intake valve and the upper air intake valve of the test bench are opened, so that the air flow is cooled in the heat exchanger and a constant temperature is maintained in the test bench. As a specifically designed piping device, the present invention can be used for a long time and multiple times in a low-temperature environment, and can achieve the refrigeration surface defrosting and supercooled droplet preparation required by the test.

Description

Technical Field

[0001] The invention belongs to the technical field of low-temperature testing, and in particular relates to a low-temperature testing environment system suitable for a closed experimental platform. Background Art

[0002] With the continuous advancement of science and technology, researchers are no longer satisfied with testing at room temperature and are gradually shifting their focus to exploring harsh environments such as low temperatures. Under these circumstances, the freezing mechanism of droplets at low temperatures has gradually attracted the attention of researchers. Low-temperature test environment control piping is a crucial component of the air circulation system that ensures the smooth operation of test bench experiments. To ensure the proper conduct of droplet tests in low-temperature environments, it is necessary to remove impurities from the air, including but not limited to small solid particles, as their presence can damage the precision test bench. Furthermore, maintaining the test bench at low temperatures for extended periods of time and minimizing temperature fluctuations place higher demands on the piping system. In this system, the piping system plays a vital role in providing environmental control in the experimental area, enabling defrosting of refrigerated surfaces and the generation of supercooled droplets. Under these stringent environmental and testing requirements, a redesigned piping system for droplet test benches suitable for low-temperature environments is essential. Summary of the Invention

[0003] The purpose of the present invention is to provide a low-temperature test environment system suitable for a closed laboratory bench, which comprehensively considers the overall pipeline, component selection and insulation measures to ensure that the refrigeration surface defrosting and supercooled droplet preparation can be achieved in a low-temperature experimental environment.

[0004] A low-temperature test environment system suitable for a closed laboratory bench comprises an air intake duct, an exhaust duct, a heat exchanger, a laboratory bench, and a booster fan; the air intake duct is connected to the air inlet of the heat exchanger and is provided with an inlet valve; the air outlet of the heat exchanger is connected to the lower air intake valve and the upper air intake valve of the laboratory bench via pipelines; the air outlets on the left and right sides of the laboratory bench are connected to the booster fan via pipelines; the exhaust duct is connected to the booster fan and is provided with an outlet valve;

[0005] During external circulation, open the inlet valve, outlet valve, lower air intake valve and upper air intake valve of the test bench. Under the action of the booster fan, the air pressure inside the test bench is balanced with the external air pressure, thus achieving internal and external air convection.

[0006] During internal circulation, close the inlet valve and outlet valve, open the lower air inlet valve and the upper air inlet valve of the test bench, so that the air flow is cooled in the heat exchanger and a constant temperature is maintained in the test bench.

[0007] Furthermore, an additional cold source is included; the additional cold source uses liquid nitrogen and is provided with a nitrogen valve, which is connected to the air outlet of the heat exchanger through a pipeline; the nitrogen valve is opened to cool and dehumidify, thereby achieving a low-temperature drying experimental environment.

[0008] Furthermore, all pipes in the piping system are made of metal reinforced hoses and are insulated on the outer surface by stacked insulation.

[0009] The beneficial effects of the present invention are:

[0010] As a specifically designed piping device, the present invention can be used for a long time and multiple times in a low-temperature environment, and can achieve the refrigeration surface defrosting and supercooled droplet preparation required by the test. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0012] Figure 2 Schematic diagram of two circulation modes in the present invention. DETAILED DESCRIPTION

[0013] The present invention will be further described below with reference to the accompanying drawings.

[0014] The present invention provides a low-temperature test environment system suitable for a closed test bench. By comprehensively considering the overall pipeline, component selection and insulation measures, it can ensure that refrigeration surface defrosting and supercooled droplet preparation can be achieved in a low-temperature experimental environment.

[0015] The present invention includes an intake duct, an exhaust duct 1, a heat exchanger 3.1, a test bench 4, a booster fan 5, and an additional cold source 6. The intake duct is connected to the air inlet of the heat exchanger 3.1 and is provided with an inlet valve 2.1. The air outlet of the heat exchanger 3.1 is connected to the lower air inlet valve 2.3 and the upper air inlet valve 2.4 of the test bench 4 via pipelines. The air outlets on the left and right sides of the test bench 4 are connected to the booster fan 5 via pipelines. The exhaust duct 1 is connected to the booster fan 5 and is provided with an outlet valve 2.5.

[0016] During external circulation, the inlet valve 2.1, the outlet valve 2.5, the lower air inlet valve 2.3 and the upper air inlet valve 2.4 of the test bench 4 are opened, and the pressure inside the test bench 4 and the external pressure are balanced under the action of the booster fan 5, so as to realize internal and external air convection;

[0017] During internal circulation, the inlet valve 2.1 and the outlet valve 2.5 are closed, and the lower air inlet valve 2.3 and the upper air inlet valve 2.4 of the test bench 4 are opened to cool the air flow in the heat exchanger 3.1 and maintain a constant temperature in the test bench.

[0018] The additional cold source 6 uses liquid nitrogen and is provided with a nitrogen valve 2.2, which is connected to the outlet of the heat exchanger 3.1 through a pipeline; the nitrogen valve 2.2 is opened to cool and dehumidify, thereby achieving a low-temperature dry experimental environment. Example

[0019] like Figure 1 The figure shows the overall structure of a low-temperature test environment system suitable for a closed test bench in the present invention. The piping system includes: an exhaust pipe 1, an inlet valve 2.1, a nitrogen valve 2.2, an air inlet valve 2.3 under the test bench, an air inlet valve 2.4 on the test bench, an outlet valve 2.5, an environmental cooling system 3, a test bench 4, a booster fan 5, and an additional cooling source 6. The environmental cooling system 3 includes its internal components, a heat exchanger 3.1, and an external unit 3.2. Figure 2 Shown are two circulation modes of a low-temperature test environment system suitable for a closed laboratory bench in the present invention, the left one is internal circulation and the right one is external circulation.

[0020] The flow of air in the pipeline can be Figure 1 The result is that after being sucked in from the outside, the gas passes through inlet valve 2.1 and is mixed with the circulating gas to enter the heat exchanger 3.1 in the ambient refrigeration system 3 for cooling. The gas then enters the experimental table 4 through the distribution of the lower air inlet valve 2.3 and the upper air inlet valve 2.4, thereby achieving the ambient temperature control inside the experimental table 4. The gas is discharged from the left and right outlets of the experimental table 4 through the booster fan 5, and the outlet valve 2.5 determines whether it is internally circulated or exhausted to the outside.

[0021] The present invention takes into account the fact that the coefficient of determination on the size of the overall piping system is relatively small during design, so hoses are generally used in the overall pipeline to facilitate layout. In terms of the selection of pipeline materials, since common PVC pipes are sensitive to temperature, metal reinforced hoses are selected as the main pipeline material. Silicone tubes can maintain elasticity at minus 40°C, meeting the needs of experimental use and ensuring experimental safety. In terms of pipeline connectors under low temperature conditions, since plastic and rubber cannot be used normally at low temperatures, and carbon steel has low-temperature brittleness, high-strength metal parts need to be used in the connection to ensure sealing. When connecting the silicone tube to the pipeline, a mixed assembly of quick-release connectors and quick-release clamps is used to make the structure easy to adjust and replace. Connectors such as tees, quick-release pagoda heads, quick-release flanges and ball valves are used in the pipeline. In terms of material insulation, stacking insulation is used from the perspective of cost and convenience.

[0022] To ensure the overall tightness of the pipeline, flat gaskets are used on the flange connections to ensure a tight seal, while sealant is applied to the outer edges of the joints for reinforcement. The flat gaskets on the flanges prevent gaps caused by thermal expansion and contraction between normal and low-temperature environments, maintaining the pipeline's tightness. The sealant reinforcement ensures a certain degree of airtightness at the connection points and protects key areas from moisture and insulation.

[0023] Due to the extensive use of high-strength metal components, the entire system presents significant quality issues, requiring auxiliary support at key locations. Therefore, a combination of brackets and profiles is used to arrange the entire pipeline, ensuring that the entire set of pipes is constrained at a specific angle and length without affecting experimental operation and observation. To maintain a stable test bench temperature during the experiment, since the heat transfer involved in the experimental temperature control process is primarily convection, an adjustable power supply is required to adjust the voltage and control the fan speed, thereby maintaining a stable experimental environment.

[0024] According to the requirements of refrigeration time and humidity, nitrogen is used through nitrogen valve 2.2 to reduce the temperature and humidity in the experimental bench to achieve a frost-free environment. The present invention has two working paths according to actual conditions. One is the external circulation working mode with the outlet valve 2.5 opened; the other is the internal circulation mode with the outlet valve 2.5 closed. The external circulation is used in the equipment startup and shutdown stages to balance the internal and external air pressures; in cold seasons, dry and cold air is directly provided by the outside world to reduce energy consumption. The internal circulation is used in the experimental stage, and the air in the pipeline is continuously refrigerated by the internal circulation, and the pipeline air is continuously dried by the drying section in the experimental bench to maintain the experimental environment.

[0025] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A low-temperature test environment system suitable for a closed laboratory bench, characterized by: The invention comprises an air intake pipe, an exhaust pipe (1), a heat exchanger (3.1), a test bench (4), and a booster fan (5); the air intake pipe is connected to the air intake of the heat exchanger (3.1), and an inlet valve (2.1) is provided on the air intake pipe; the air outlet of the heat exchanger (3.1) is respectively connected to the lower air intake valve (2.3) and the upper air intake valve (2.4) of the test bench (4) through pipelines; the air outlets on the left and right sides of the test bench (4) are respectively connected to the booster fan (5) through pipelines; the exhaust pipe (1) is connected to the booster fan (5), and an outlet valve (2.5) is provided on the exhaust pipe; All pipes in the piping system use metal reinforced hoses, and the outer surface is insulated by stacked insulation; It also includes an additional cold source (6); the additional cold source (6) uses liquid nitrogen and is provided with a nitrogen valve (2.2), which is connected to the gas outlet of the heat exchanger (3.1) through a pipeline; During external circulation, the inlet valve (2.1), the outlet valve (2.5), the lower air intake valve (2.3) and the upper air intake valve (2.4) of the test bench (4) are opened, and the air pressure inside the test bench (4) and the external air pressure are balanced under the action of the booster fan (5), thereby achieving internal and external air convection; During internal circulation, the inlet valve (2.1) and the outlet valve (2.5) are closed, and the lower air inlet valve (2.3) and the upper air inlet valve (2.4) of the test bench (4) are opened to cool the air flow in the heat exchanger (3.1) and maintain a constant temperature in the test bench; Open the nitrogen valve (2.2) to cool and dehumidify to achieve a low-temperature dry experimental environment.

Images