低温热压缩机系统的数值模拟与实验研究

Numerical and Experimental Study of a Low-temperature Thermal-compressor

本文对低温热压缩机系统进行了数值模拟和实验研究,首先对低温热压缩机的运行参数进行了研究,结果表明提高运行频率、增大平均力、降低预冷温度均可增大系统的压比,但同时也会消耗更多的预冷量。之后对热压缩机所需的预冷量和各项热损失进行了分析,结果表明排出器运动产生的损失所占比例最大,是进一步优化的重点。最终本文所研究的低温热压缩机系统,在2 Hz运行频率下、平均压力1 MPa时,所需要的冷量约为54 W@77K,系统可产生1.95的压比。基于此热压缩机系统,进一步驱动单级多路旁通脉冲管制冷机,可成功获取3.8 K的最低温度。

A numerical and experimental study of low-temperature thermal-compressor was presented in this paper. Firstly, the operating parameters of low-temperature thermal-compressor were studied. The results showed that the pressure ratio in the system would increase with the increasing of operating frequency, average pressure and decreasing of pre-cooling temperature, but the precooling power would increase at the same time. Then, the amount of precooling power and thermal-losses were analyzed. The results showed that the thermal-loss caused by the movement of displacer was largest, which was the most important optimizing factor in the next work. Finally, this thermal-compressor has obtained a pressure ratio 1.95 with operating frequency 2 Hz, average pressure 1 MPa and 54 W@77 K precooling power. Based on this thermal-compressor, a lowest temperature 3.8 K has been obtained in a single-stage multi-bypass pulse tube cryocooler.