Dynamic study of a metal hydride pump

Abstract

Metal hydride pump (MHP) is one of the unconventional pumping systems which converts thermal energy into mechanical energy. This pump operates in an autonomous mode without the consumption of electric power. So, it is used to solve problems of availability of electricity or fossil energies in certain freestanding regions. In this paper, a mathematical model that describes a dynamic behavior of a MHP is carried out with Mg2Ni alloy using an unsteady model (the time-space evolution of temperature and hydrogen concentration within the reactor is taken into account). Using this model, a computer code has been developed and used to predict the time evolution of the specific water discharge and the effect of different operating parameters (heating temperature, desorption gear ratio, surfaces of hydrogen, and pumping pistons) on the performance of the MHP. Simulation results show that depending on operating conditions, it is possible to pump as much as 890 L of water at a desorption temperature of 673, K using 1 kg of Mg2Ni.