Characteristics of non-uniform reaction blocks for chemical heat pump

The non-uniform reaction blocks were manufactured by the impregnation of metal salts into the expanded graphite to improve the heat and mass transfer ability for the chemical heat pump. In contrast with the ordinary reaction blocks of the uniform proper-ties such as the apparent density and ratio of the expanded graphite, the non-uniform reaction blocks were prepared to increase the apparent density with radius direction: 165, 222, 279, 337, 394 kg/m(3) gradually. The experimental results show that the non-uniform reaction block can improve the heat transfer properties and additionally overcome the mass transfer limitation due to high apparent density of the block which diminishes the permeability of ammonia gas. (C) 2004 Elsevier Ltd. All rights reserved.