Optimization of the working fluid for a sorption-based Joule–Thomson cooler

•We present a general method for working-fluid optimization in a sorption JT cooler.•The working fluid of a single-stage sorption JT cooler is optimized.•The optimization method is extended to two-stage compression. Sorption-based Joule–Thomson coolers operate vibration-free, have a potentially long life time, and cause no electromagnetic interference. Therefore, they are appealing to a wide variety of applications, such as cooling of low-noise amplifiers, superconducting electronics, and optical detectors. The required cooling temperature depends on the device to be cooled and extends into the cryogenic range well below 80K. This paper presents a generalized methodology for optimization in a sorption-based JT cooler. The analysis is based on the inherent properties of the fluids and the adsorbent. By using this method, the working fluid of a JT cooler driven by a single-stage sorption compressor is optimized for two ranges of cold-tip operating temperatures: 65–160K and 16–38K. The optimization method is also extended to two-stage compression and specifically nitrogen and carbon monoxide are considered.