Pouria Pakzad - MSc, Department of Renewable Energies and Environment, Faculty of New Sciences and Technologies, University of Tehran, Tehran, Iran
Mehdi Mehrpooya - Associate Professor, Department of Renewable Energies and Environment, Faculty of New Sciences and Technologies, University of Tehran, Tehran, Iran

The purpose of this study is to design and introduce a novel cryogenic system that produces liquid helium. This study's novelty is producing liquid helium stream at almost atmospheric pressure by a novel process and uses a unique expander to reach the proposed state. Two methods of the first and second law of thermodynamic approach are used to investigate the proposed system. In this novel cryogenic system, liquid helium is produced at three stages; first, the mainstream contains some helium enters to helium upgrader process to increase helium concentration. After that, the stream with a high helium concentration enters to pressure swing adsorption process, and pure helium is obtained. Finally, pure helium enters to cryogenic process and liquified in an expander. The net-work consumption in this system is equal to 18.66 MW, and the exergy efficiency of the proposed system is obtained at 23.4%. Also, the results show that this system can produce 196.5 kg/h liquid helium. In this study, Aspen HYSYS and MATLAB software were used simultaneously to simulate this cryogenic process. Finally, numerical assessment is done on the key parameters which influence the performance of the process.

Liquid Helium, Cryogenic system, Pressure swing adsorption, Exergy analysis