自由活塞斯特林制冷机间隙密封技术研究  

Study on the clearance seal in free-piston Stirling cooler

作　　者：陈曦[1] 武卫东[1] 周志刚[1] 张华[1] 吴亦农[2] 

机构地区：[1]上海理工大学动力工程学院,上海200093 [2]中科院上海技术物理研究所,上海200083

出　　处：《低温与超导》2008年第5期5-8,12,共5页Cryogenics and Superconductivity

基　　金：上海高校选拔培养优秀青年教师科研专项基金(563102);上海理工大学博士启动基金(X718);上海市重点学科建设项目(T0503)

摘　　要：间隙密封作为自由活塞斯特林制冷机中的一项关键技术,可以在完成密封作用的同时消除接触磨损和因此而产生的污染,同时由于间隙内气体的泄漏,引起了冷量损失,使制冷量减少。文中建立了层流工况下间隙密封的数学模型,推导了密封间隙的泄漏率。针对自由活塞斯特林制冷机的结构,对三处不同位置的间隙密封分别进行分析,提出了不同位置的间隙密封设计要求。对于直线压缩机的间隙密封,压缩机间隙密封的泄漏会带来压力波损失并同时影响压缩机固有频率;为消除压缩活塞的偏置,要求周期泄漏量为零,对于膨胀机的间隙密封,除了泄漏损失还包括了穿梭损失和摩擦损失等。最后,考虑实际加工和装配工艺的局限性,对间隙密封的偏心影响进行了分析,并对自由活塞斯特林制冷机间隙密封的安装技术和检测手段提出了简单的建议。As a key technology of free - piston Stirling cooler, the method of clearance seal can achieve the seal effect, eliminate contact abrasion and decrease the contamination from sealing face. But, the gas leakage of clearance seal leads to the leakage losses and the reduction of the cooling capacity. The paper establishes the mathematical and physical model of the leakage of the clearance seal in Stirling cooler with clearance seals, and describes a set of equations of the leakage and the leakage losses of the clearance seal. According to the structure of free - piston Stirling cooler, after three different clearance seals were analyzed, the design references were put forward. To the seal between the piston and cylinder wall in linear compressor, the seal leakage would decrease pressure wave and affect compressor natural frequency. At the same time, in order to eliminate piston shift, the cycle leakage rate should be zero. To the seal between the displacer and cylinder wall, the losses include shuttle loss and friction loss besides leakage loss. At last, considering practical manufacturing procedure and assembly technology, the eccentricity effects of clearance seal were analyzed, and some advices about assembly technology and test method were put forward.

关 键 词：自由活塞斯特林制冷机 间隙密封 直线压缩机 泄漏损失 

分 类 号：TB651[一般工业技术—制冷工程] TH136[机械工程—机械制造及自动化]