【摘要】 建立了一套液氦温区Ｇ－Ｍ型制冷机Ｐ－Ｖ图测试系统，测试装置主要包括制冷机进、排气和冷、热腔压力的压力测量系统及制冷机活塞位移的测量系统。该系统将制冷机动态压力、动态位移的测量信号通过采集系统送入微机中进行处理，可实时绘制压力及Ｐ－Ｖ图图形曲线，随时掌握不同结构不同工况下Ｇ－Ｍ制冷机压力损失和Ｐ－Ｖ图效率情况，为制冷机性能的改进、制冷机的理论分析及设计计算提供了可靠的实验依据。通过测试系统，测试了制冷机冷腔在不同制冷温度下的Ｐ－Ｖ图效率，指出在深低温区冷腔Ｐ－Ｖ图面积并不代表制冷机实际制冷量。更多还原

【Abstract】 A measurement system of the P-V diagram of a 4.2 K G-M refrigerator is established in this paper. The pressure curves vs. time of the 2nd stage cold space, admission line and exhaust line of the 4.2 K G-M refrigerator and the P-V diagram of the 2nd stage cold space can be obtained by the measurement system. By comparing the P-V diagram efficiency with the ideal and real cooling capacities, it was indicated that the increased P-V diagram area at low temperature (<8 K or so) doesn’t represent the net increased cooling capacity. In addition, the pressure drops in the admission line and exhaust line greatly increase with the cooling temperature decreasing.更多还原