大负载高温变率高低温试验系统

High-and-Low Temperature Testing System with Characteristics of Large Load and High Temperature Change Rate

目的研制一种闭合循环单回路方式的大负载高温变率高低温试验系统,并介绍其设计思路和关键技术,其有效负载高达1.0 t(铝),温变率最高可达5℃/min以满足产品的实测需求。方法针对大负载高温变率的要求,对加热制冷的方式以及功率进行设计;针对试验系统试验舱大空间、大负载等特点所造成的空间温度梯度大,波动剧烈的难点,对各个系统进行协调设计,特别提出低温系统的引射雾化设计以及温度积分分离的控制策略等创新点。结果高低温试验系统工作区的温度在升温阶段实现了较好的温度变化跟随性,在稳定阶段具有较好的空间均匀性和波动性,工作区各点温度均匀性≤2℃,温度波动度性≤±0.5℃。结论采用闭合循环单回路方式,并通过低温系统的引射雾化设计以及温度积分分离的控制策略,可以实现大负载高温变率高低温试验系统的空间均匀性和波动性以及温变跟随性的要求。

Objective To develop a high-and-low temperature testing system with characteristics of large load and high temperature change rate,and introduce its key technologies and design thoughts.Its payload was up to 1.0 t(aluminum)and the temperature change rate was up to 5℃/min to meet the requirement on actual measurement.Methods In order to satisfy requirements of the large load and high temperature change rate,the heating and refrigeration methods and power were designed.Because of characteristics of large space and large load in test zone,the space temperature gradient would be large and temperature would fluctuate dramatically.In view of these difficulties,coordinated design of each system was done.Especially,the design of ejector atomization in low temperature system and temperature integral separation control strategy were put forward.Results The temperature in test zone achieved a better follow in the temperature change stage and it has good spatial uniformity and volatility in the stable stage.Temperature uniformity in space was less than or equal to 2℃,and volatility was less than or equal to±0.5℃.Conclusion By using the closed single loop mode,and through design of ejection atomization and the control strategy of temperature integral separation,the space uniformity and fluctuation of the high-and-low temperature testing system and the requirement of temperature variation can be realized.