排出器等效机械阻尼对自由活塞斯特林制冷机性能影响的数值模拟  

Numerical study on influence of equivalent mechanical damping coefficient of displacer upon performance of a free-piston refrigerator

作　　者：李小伟[1,2] 余国瑶[1] 戴巍[1] 罗二仓[1] 陈燕燕[1] 

机构地区：[1]中国科学院理化技术研究所低温工程学重点实验室,北京100190 [2]中国科学院大学,北京100049

出　　处：《低温工程》2016年第1期1-5,37,共6页Cryogenics

基　　金：国家自然科学基金重大项目(52376187;51206177)资助项目;中国科学院理化所所长基金项目(热声热泵)资助项目

摘　　要：针对一台设计目标为300 W@80 K自由活塞斯特林制冷机,数值计算研究了排出器等效机械阻尼R_m对制冷机性能的影响及其作用机理。研究发现,R_m对制冷机的影响主要有两方面,一是直接影响排出器处的摩擦损失,导致制冷机性能变化;其次是改变了系统的声场分布,导致其他核心部件如回热器和换热器的损失变化。此外,制冷机入口声阻抗特性随之发生变化并进一步影响制冷机与压缩机的耦合性能。计算结果表明,维持制冷机输入声功1 363 W不变,当R_m由25 Ns/m增大至100 Ns/m时,制冷机制冷量由194.7 W降低至160.9 W,相对卡诺效率由38.9%降低至32.2%。Using numerical computing software Sage for a 300 W@ 77 K free piston Stirlingcooler,the influence of equivalent mechanical damping coefficient of the displacer R_mupon the cooler performance and the corresponding mechanisms behind it were studied. The study results show that the influenceof changingR_mon the cooler results from two main aspects,one is the direct friction loss,the other is the changedacoustic field distribution of the system which leads to the changes of exergy loss inside some key components. Meanwhile,the inlet acoustic impedance of the cooler is changed and hence influences the coupling between the cooler and compressor. Calculations show that maintaining the input acoustic power of the coolerat 1 363 W,with Rmincreased from 25 N /（ m/s） to 100 N /（ m/s）,cooler cooling capacity reduced by lower 33. 8 W and the relative Carnot efficiency decreased by 6. 8 percentage points from 38. 9%.

关 键 词：热工学 制冷与低温工程 自由活塞斯特林制冷机 排出器 等效机械阻尼 

分 类 号：TB651[一般工业技术—制冷工程]