高低温试验箱温度均匀性调节技术研究

Research on temperature uniformity regulation technology of a high and low temperature test chamber

温度均匀性是保证高低温试验箱实验结果有效性和可信性的重要指标。现有关于高低温试验箱出风口气流组织形式对温度均匀性影响的研究主要通过仿真模拟技术,并且都忽略了试验箱风道在宽度方向的不均对试验箱整体温度均匀性的影响。通过对设备温度均匀性、调节复杂度、能耗情况等进行比较,在内箱容积均为1000 L的高低温试验箱中,实验了3种不同的温度均匀性调节技术,即可调百叶、热气除霜、双边进蒸发器等。结果发现双边进蒸发器技术更加有益于设备风道内部换热,可有效排除因试验箱风道温度不均对实验结果的影响,并且在同一试验箱中分别实验了3种出风口形状(正方形、圆形、菱形)及不同风速下试验箱的温度均匀性。结果表明:风速对环境试验箱的影响很大,风速越高,试验箱温度均匀性越好。当风速相同时,在高温工况下,出风口形状对试验箱温度均匀性的影响很大,方形出风口温度均匀性最好;在常温及低温工况下,出风口形状对试验箱温度均匀性的影响很小。

Temperature uniformity is an important indicator to ensure the validity and credibility of the experimental results of the high and low temperature test chamber.The existing studies on the influence of the air distribution of the air outlet of the high and low temperature test chamber on the temperature uniformity are mainly through simulation technology,and all ignore the influence of the uneven width of the air duct of the test chamber on the overall temperature uniformity of the test chamber.By comparing the temperature uniformity,regulation complexity and energy consumption of the equipment,three different temperature uniformity regulation technologies are experimented in the high and low temperature test chamber with an inner chamber volume of 1000 L,namely regulation louver,hot gas defrosting,and bilateral inlet evaporator.The results show that the bilateral inlet evaporator technology is more beneficial to the internal heat exchange of the air duct of the equipment,which can effectively eliminate the influence of the uneven temperature of the air duct of the test chamber on the experimental results,and the temperature uniformity of the test chamber under different wind speeds is tested in the same test chamber with three air outlet shapes(square,round and diamond)respectively.The results show that the wind speed has a great influence on the environmental test chamber,and the higher the wind speed,the better the temperature uniformity of the test chamber.When the wind speed is the same,the shape of the air outlet has a great influence on the temperature uniformity of the test chamber under high temperature conditions,and the temperature uniformity of the square air outlet is the best.Under normal and low temperature conditions,the shape of the air outlet has little effect on the temperature uniformity of the test chamber.