基于应变片的自由活塞斯特林制冷机位移测试研究

Study on displacement measurement of free-piston Stirling cooler based on strain foil

压缩活塞与排出器的位移大小及相位差对自由活塞斯特林制冷机的制冷性能具有极其重要的影响。文中通过对目前各种位移测试方法优缺点分析,结合自由活塞式斯特林制冷机自身特点,提出了采用应变片响应涡旋柔性弹簧形变来测量活塞和排出器位移的新方法。通过分析、设计和标定,建立了一套基于应变片的自由活塞斯特林制冷机位移测量系统。实验测试结果表明,该位移测量系统是可靠的,具有体积小、投资省等优点,且不需要特别的安装空间。

The displacements and phase shift of piston and displacer have important effects on the performance of free - piston Stifling cooler, in this paper, at first, the merits and faults of various displacement measurement methods at present were detailedly analysed. According to structure characteristics of free -piston Stirring cooler, a new displacement measurement method was put forward, that strain foils were used to measure indirectly the displacements of piston and displacer by responding to shape change of spiral flexure spring. After finishing analysis, design and calibration to strain foil, the displacement measurement system based on strain foil was built up for free - piston Stifling cooler. The experimental testing results indicate that the displacement measurement system is reliable, simpler and cheaper, which needs not special installation site.