Developing Mixed Refrigerant Joule-Thompson Cryocooler in the Range of 60 K

Mixed Refrigerant Joule-Thompson (MRJT) cryocoolers, that use Linde-Hampson cycle, have been successfully demonstrated to reach temperatures above 80 K. In the present work, MRJT cryocooler to reach temperatures below 80 K is developed using a liquid-vapour (LV) phase separator. By incorporating LV separator in the system, the cryocooler essentially becomes an two-stage autocascade cycle. Development of an inhouse LV separator operating at cryogenic temperature is presented. The minimisation of the thermal mass of the separator is carried out using several iterations achieving a final mass of 490 grams from an initial mass of 1555 grams. Using the two-stage MRJT system, uncertainties associated with the LV separation process created irregular flow of refrigerant in the second stage resulting in choking the second stage. Lowest temperature of 61 K is achieved using the two-stage MRJT cryocooler and cooling effect of 4 W is obtained at 70 K.