Influence of the adsorber heat exchanger design on the performance of the heat pump system

摘要

Research activity on adsorption the pumps is mainly devoted to the improvement of the heat transfer inside the adsorber bed. To achieve this, various new types of heat exchanger designs and use of additives have recently been proposed. In this paper a study is made into the effect of an increased amount of metal in the adsorbent bed on the coefficient of performance (COP) and on the specific power This correspondingly affects the energy delivered to the user and the investment cost of the system. A simplified dynamic model has been developed to calculate the performances of the machine as a function of the extra heat capacity, the global heat transfer coefficient and the cost of the material. Finally, a general diagram is proposed in order to evaluate the minimum heat transfer improvement that must be obtained with a higher heat exchanger surface, or when additives and metallic structures, are inserted into the absorber bed in order to increase the specific power of the machine.