Performance analysis of a miniature Joule_Thomson cryocooler with and without the distributed J_T effect

Cryogenic Engineering Conference 2015

材料科学;物理学

Damle, Rashmin^1 ; Atrey, Milind^1

Department of Mechanical Engineering, Indian Institute of Technology Bombay, Powai, Mumbai Maharashtra

400076, India^1

关键词: Biological samples;    Cooling technique;    Cryogenic temperatures;    Different operating conditions;    Operating condition;    Performance analysis;    Recuperative heat exchangers;    Storage reservoirs;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/101/1/012168/pdf
DOI  :  10.1088/1757-899X/101/1/012168

学科分类：材料科学（综合）

来源: IOP

【 摘 要 】

Cryogenic temperatures are obtained with Joule-Thomson (J-T) cryocoolers in an easier way as compared to other cooling techniques. Miniature J-T cryocoolers are often employed for cooling of infrared sensors, cryoprobes, biological samples, etc. A typical miniature J-T cryocooler consists of a storage reservoir/compressor providing the high pressure gas, a finned tube recuperative heat exchanger, an expansion valve/orifice, and the cold end. The recuperative heat exchanger is indispensable for attaining cryogenic temperatures. The geometrical parameters and the operating conditions of the heat exchanger drastically affect the cryocooler performance in terms of cool down time and cooling effect. In the literature, the numerical models for the finned recuperative heat exchanger have neglected the distributed J-T effect. The distributed J-T effect accounts for the changes in enthalpy of the fluid due to changes of pressure in addition to those due to changes of temperature. The objective of this work is to explore the distributed J-T effect and study the performance of a miniature J-T cryocooler with and without the distributed J-T effect. A one dimensional transient model is employed for the numerical analysis of the cryocooler. Cases with different operating conditions are worked out with argon and nitrogen as working fluids.