Comparative Study between precooled Claude Liquefaction Cycle and an Active Magnetic Regeneration Cycle applied to Hydrogen Liquefaction

Abstract

The present work aims at performing a comparative study between precooled Claude cycle and an Active Magnetic Regeneration Cycle (AMR cycle) applied to hydrogen liquefaction. It deals with a comparison between performances and energy consumption evaluated for the two systems at similar operating conditions. For Claude system, energy and material balances have been performed by using Aspen Hysys simulator. Thus, liquefaction power, energy consumption and coefficient of performance (COP) have been calculated. While, the AMR system considered is constituted of 6 stages operating in cascade. Each stage contains two regenerator beds, composed of a typical magnetic material, through which a carrier fluid is forced to follow alternatively between two heat reservoirs. Thermal analysis and evaluation of performances have been performed at once by a numerical model, developed on the basis of energy equations for fluid and solid within the regenerator bed, and Aspen Hysys simulator. Using the following magnetic materials (Gd, Dy, Tb and Ho), the COP found for the AMR system is 0.096. This value is higher than Claude cycle efficiency for which a COP of 0.094 was found. In terms of energy consumption, the value found for the AMR cycle is 0.053 kW which can be neglected compared to the Claude cycle consumption (14.5 kW).

Keywords

• magnetic refrigeration
• active magnetic refrigeration cycle
• magnetic materials
• hydrogen liquefaction
• conventional liquefaction cycles