Performance of the one-stage Joule-Thomson cryocooler fed with a nitrogen-hydrocarbon mixture and built from mass-produced components made for the refrigeration industry

This paper describes the theoretical performance and working parameters of a Joule-Thomson (J-T) cryocooler that is supplied with a nitrogen-hydrocarbon mixture and works in a closed cycle. Nowadays, they are the subject of intensive research in different laboratories around the world, especially in Asia and the USA. The industrial application of this type of cooler is significantly limited by the high values of working pressure for pure nitrogen. Supplying the system with a mixture of nitrogen and hydrocarbons makes it possible to reduce the level of the working pressure down to that which is achieved by commercially available compressors produced for the refrigeration industry. A theoretical analysis of the performance of the cooler is presented, along with the experimental results for different mixtures. The described cooler is characterized by high reliability, simple construction in the low-temperature section, and relatively low manufacturing costs. The system produces about 10 W of cooling power at an approximate temperature of 90 K. The cooling power can be used to cool down high-temperature superconductor magnets, in nanotechnology, for cryomedical applications, and to liquefy small amounts of nitrogen, argon, oxygen, or methane.