Analytical Characteristics of Tube Plate Adsorption Heat Pump : Thermal Design of an Adsorption Reactor

Abstract

The development of an energy-supply system which is considerably efficient and does little harm to the environment is desirable. Adsorption heat pumps satisfy these two requirements because they use low-level thermal energy as a driving force, and use safe and natural substances ; silica gels or zeolites as adsorbents and water as the refrigerant. A tube plate reactor in which adsorption and desorption take place is proposed here to make the system compact, to enhance heat transfer, and to provide heat storage capacity. As a simple measure to evaluate heat and mass transfer in adsorbent beds, the concept of equivalent thermal conductivity was defined and identified through fundamental heat and mass transfer experiments and simulations. However, the equivalent thermal conductivity obtained is so small that fins must be adopted. In this paper, thermal design of the adsorption reactor is developed through simulations using the equivalent thermal conductivity of adsorbent beds, and as a result, the relationship between heat storage capacity, COP, and required area for the adsorption reactor is quantitatively evaluated.