Parametric studies on a heat operated metal hydride based water pumping system

The principle of metal hydride based thermal sorption compressor is adapted for water pumping application. Desorption of hydrogen at high pressure and its absorption at low pressure by a metal hydride are used to expand and contract a bellow which pumps an equivalent amount of water. A part of the pumped water is used to cool the bed to facilitate the absorption process, simultaneously yielding warm water. A parametric study is carried out for mischmetal alloy (MmNi4Al) at various pump heads, warm water temperatures, dead volumes of bellow and heat loss through bellow. It is observed that hydride based water pumping is suitable for 'low discharge and high head' conditions, particularly due to its capability to heat a portion of pumped water. © 2002 International Association for Hydrogen Energy. Published by Elsevier Science Ltd. All rights reserved.