Experimental study on activated carbon–nitrogen multi-stage thermal sorption compressors

Heat powered cycles are of great interest as they enable reduced electric power consumption. Therefore, they can lower the load on electric power plants and distribution infrastructure. Many systems incorporate compressors for driving thermodynamic cycles and processes, and these compressors are usually electrically driven. In the framework of research on a sorption Joule-Thomson cryogenic cooler, a three-stage sorption compressor is designed, manufactured, and tested. The experimental results are reported and analyzed in the current manuscript. Nine experiments are reported, with one, two, and three compression stages, in which the experiments differ in the number of sorption cells at every compression stage and the operating conditions. The results of the experimental apparatus validate a numerical model and show the ability to construct and operate sorption compressors. All nine experiments operate with nitrogen, which is the required refrigerant in the cryogenics cooling system of the current research. Nitrogen is a weakly adsorbed gas, and so the reported efficiencies are relatively low, around 0.5% of the Carnot efficiency. However, the current work proves the technology's maturity and suitability for many other applications, especially where the required working fluids are more intensively adsorbed gases.