Simulation of the metal hydride heat pump system with the single and double reactors

Abstract

The main obstacles for the practical use of a metal hydride heat pump (MHHP) system are a low-heat transport rate of the metal hydride and a relatively large irreversible heat loss during the hydriding and dehydriding processes. Very extensive investigations are required to overcome these obstacles, which are both time-consuming and costly. In order to save both time and cost, computer simulation can be introduced in the development of such MHHP systems. In particular, simulation can provide useful technical knowledge for improving the system by optimum reactor construction and identification of optimum operational parameters. In this work, a simulation method for the MHHP system, based on the three-vector equilibrium space of temperature, concentration and enthalpy, is proposed and tested practically. Using a computer simulation program for a single reactor MHHP system driven by a given pressure or flow rate of hydrogen, it was possible to describe equilibrium properties of hydride as they are changed by variations in temperature and concentration. Simulation of the MHHP system with two reactors, i.e. one metal hydride pair, allowed the thermodynamics of a conventional system to be described theoretically.