关键部件对自由活塞斯特林制冷机制冷性能的影响

Effects of key parts on the refrigeration performance of free-piston Stirling cooler

实验测试了两种不同丝网蓄冷器的流阻特性及其对整机制冷性能的影响,表明在低温下需要设计小空隙率,而在高温区需要设计大空隙率.通过改变冷头材料,实验测试了冷头表面温度的变化情况.比较了不同制冷量下两种冷头的表面温差,表明制冷量越大,冷头材料导热系数对两者表面温差的影响越大.通过粘贴排出器垫块,改变冷端死容积.分析了死容积对整机性能的影响,在200 K温度以下,死容积越小,制冷性能越好,但在240 K以上的高温区,制冷性能受死容积的影响较小.

The flow resistance two regenerators with different mesh screens and their effects on the performance of free piston stirling cooler were tested respectively. It is indicated that small void ratio is needed for low temperature and large one is needed for high temperature. The heat exchanger on the cold end surface was tested by changing the material of the cold end. The difference of temperature between two cold ends was examined with different cooling capacities, and it is indicated that the larger cooling capacity, the greater effect of thermal conductivity coefficient of the cold end material on the difference of temperature between two cold ends. The influence of dead volume on the performance of cooler was analyzed with affixing pad to change the dead volume at cold end. Some results were received：below 200 K, the less dead volume, the better cooling performance; above 240 K, there is little affection on refrigeration performance.