Characteristic Analysis And Optimal Design Of Temperature Field And Flow Field Of High And Low Temperature Test Chamber

The high and low temperature test chamber is used to test the reliability of various materials or electronic products at different ambient temperatures.It is the most important equipment in environmental testing equipment.In order to improve the reliability of the test results of the test box,the paper uses the 800L high and low temperature test box For the research object,the thermal insulation performance of the outer box structure of the test box,the angle position of the air inlet in the test area,and the wind speed of the air inlet were analyzed and optimized,and the temperature range and uneven coefficient of the temperature field in the test area were linearly regression analyzed.The main research work is as follows:(1)The heat transfer and heat preservation analysis of the test box body shows that the natural convection heat transfer coefficient of the top and bottom surfaces of the outer wall of the test box varies greatly under different internal temperatures;The convective heat transfer coefficient of the two side walls of the test box and the temperature change law are basically the same;As the thickness of the insulation layer increases,the heat transfer gradually decreases and the insulation performance improves;Compared with the heat conduction of air and vacuum as the insulation layer of the test box,glass wool and polyurethane foam board are the best insulation materials.(2)Using response surface analysis and multi-objective optimization to solve the optimal air supply angle and position,the results show that when the four guide plate angles of the air supply outlet are 76°,31°,33° and 340 respectively,and the side distance is 275mm and 30mm respectively,the non-uniformity coefficient decreases from 2.158 to 0.222,which improves the uniformity of the flow field.(3)Six kinds of air supply schemes are designed,and the temperature change rate,temperature field range,energy utilization coefficient and non-uniformity coefficient of six kinds of flow field models are calculated respectively.By comparing the calculation results,it can be known that the influence of six kinds of air supply speeds on the temperature change rate of the flow field is basically the same,but increasing the air speed can reduce the temperature range in the flow field;When the wind speed is 7 m/s,the unevenness coefficient is the smallest and the energy utilization coefficient is the largest,which verifies that the optimal wind speed of the test box is 7 m/s.(4)The flow field models of eight sizes of loads in the test area were established.The load heating power and supply air temperature were set as independent variables,and the temperature range and temperature non-uniformity coefficient were set as dependent variables.The linear regression analysis of the variables was carried out by SPSS.The results show that there is a good linear relationship between the four variables.(5)By testing the temperature field of the 800L high and low temperature test chamber,and comparing the test results with the simulation value,the maximum relative error is 0.55%,which verifies the reliability of the numerical simulation analysis.Through the analysis and optimization of the temperature field and flow field of the high and low temperature test chamber,the uniformity of the temperature field and flow field is improved,which provides a reference for the design and development of the high and low temperature test box.Figure[48]table[21]reference[81]...