A theoretical thermal model for a heat pump module using evacuated tube solar adsorption

The study focuses on analyzing a novel design of an evacuated glass tube solar adsorption cooling module, which combines an adsorption-based heat pump system and an evacuated glass tube solar collector into a single component module. The module consists of a single-wall evacuated glass tube, with the adsorbent bed (generator) located on one side (top section) and the evaporator/condenser with refrigerant on the other side (bottom section). The study presents a theoretical model of the module, based on previous experimental data, indicating promising results in terms of energy efficiency. The adsorbents examined, both zeolite 13X as well as silica gel type-RD, both adsorbents have an ideal design point in terms of adsorbent bed diameter, radiation heat flux, and glass tube diameter, as shown by the analysis. A comprehensive thermodynamic analysis of an evacuated tube adsorption heat pump module by analyzing the heat transfer mechanisms and energy balance involved in the module's operation. Through thermodynamic analysis, the solar coefficient of performance (COP) of evacuated glass tube adsorption heat pump module for zeolite and silica gel type-RD is 0.11 and 0.2 respectively.