Mechanical Engineering Commons^™

Second Law Analysis Of Active Magnetic Regenerative Hydrogen Liquefiers, L. Zhang, S. A. Sherif, T. N. Veziroglu, John W. Sheffield

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Recent published work in the area of magnetic refrigeration reports on its potential for greater efficiency and high reliability. This paper presents an exergy analysis of a three-stage active magnetic regenerative (AMR) hydrogen liquefier which cools a hydrogen gas stream at 77 K and 1 atm to hydrogen liquid at 20 K. Ortho - para conversion of hydrogen is accomplished in a heat exchanger employing a 10 atm helium fluid that cycles in the refrigerator. The performance of the system is described in terms of the cooling capacity and exergy losses as functions of the magnetic material type, magnetic bed …