空间自由活塞斯特林发电机启动温度研究

Study on start-up temperature of space free piston stirling generator

为确定空间自由活塞斯特林发电机的启动温度,提出一种结合动力学模型预测启动温度的简单方法.首先建立了包含热力学和动力学的发电机线性模型,利用根轨迹技术并依据系统的不稳定性判定方法预测发电机的启动温度.运用该模型分析了实验样机的启动温度以及配气活塞板簧刚度和外负载对启动温度的影响,并进行实验验证.结果表明:发电机的启动温度与配气活塞板簧刚度成正相关关系,而与外负载成负相关关系,模拟结果与实验有较好的一致性.但由于模型的理想化,模拟结果存在误差且该误差随着热端温度的升高而增加.此外,利用该模型预测发电机的运行频率,结果表明误差低于5.9%.

To obtain the start-up temperature of the space free piston Stirling generator, a measurement with dynamic model predictions was presented.A linear model which incorporated thermodynamics and dynamics was established,and the root locus technique was used to predict the generator start-up temperature according to the system instability.With the usage of the model,the start-up temperature and its variations with the changes of displacer spring stiffness and external load of a prototype were analyzed,which were compared with experiment results.The results show that the start-up temperature has a positive and negative correlation with the displacer spring stiffness and the external load,respectively.The simulation results show good agreement with experiment.However,there exists errors between the experiment and simulation results due to the idealization of the model,which are increased with the hot end temperature.In addition,the predicted frequency error is less than 5.9%.