EXPERIMENTAL INVESTIGATION ON MIXED REFRIGERANT JOULE THOMSON (MR J-T) CRYOCOOLER

Mixed Refrigerant Joule Thomson (MR J-T) cryocoolers have obvious advantages, such as low cost, high reliability, higher cooling effect at 80 K, low vibrations and simplicity in design layout. As a result of this, their use for different applications has become a major threat to conventional cryocoolers such as Stirling coolers. The performance of the MR J-T cryocooler, in terms of cooling power at low temperatures, depends significantly on the components of the gas mixture and their concentration. An experimental set up has been developed in our laboratory to analyse various gas mixtures. An efficient Hampson type counter flow heat exchanger has been fabricated and tested in the set up. The present paper gives experimental results for various gas mixtures so as to get maximum cooling effect for a given temperature. The paper also presents the effect of working pressure of the optimized gas mixture on the performance of the cooler.