基于PV图的氦工质有阀线性压缩机实际循环

Actual Cycle of Helium Valved Linear Compressor Based on PV Diagram

为了探究氦工质有阀线性压缩机实际循环的吸气量,课题组对液氦温区JT制冷用线性压缩机PV图开展研究。采用理论与实验相结合的方法,分析了余隙容积、进排气阀处压力脉动对线性压缩机吸气量的影响;基于实验室现有?18 mm氦工质有阀线性压缩机,搭建有阀线性压缩机性能测试平台,通过进排气阀前的压力传感器获得压缩腔内动态压力变化,结合课题组LVDT活塞位移测试技术,得到实际工作状态下压缩腔内的PV图。与理论分析进行对比,结果表明理论循环与实际循环吸气量差异显著。该研究为氦工质有阀线性压缩机性能的提升提供设计思路。

The studies on the PV diagram of a linear compressor for JT cryocooler at liquid helium temperature were carried out to analyze the actual cycle inspiratory volume of a helium valved linear compressor(VLC).The influences of pressure fluctuation caused by the suction and the exhaust valves and cylinder clearance volume on the inspiratory volume were analyzed by combining theories and experiments.Based on an existing VLC using^4He with the piston diameter of 18 mm in our laboratory,a VLC performance test platform was built to obtain the changes of dynamic pressure in the compression chamber through the pressure sensor set before the suction and the exhaust valves.Combined with the LVDT piston displacement test technology,the changes of pressure(P)and volume(V)in the compression chamber were obtained under actual working conditions.Compared with the theoretical analysis,the result show that the inspiratory volume between the theoretical cycle and the actual cycle is significantly different.Furthermore,the study can provide a design idea for the performance improvement of^4He VLC.