Numerical and Experimental Analysis of Porosity Effect on the Performance of a Small-scale Thermochemical Reactor

The process of thermo-chemical energy storage is based on reversible adsorption-desorption reaction, which is endothermic during desorption and exothermic during adsorption. In this work the suitability of Magnesium sulphate (MgSO4) as a thermo-chemical material, is investigated and the parameters affecting the performance of the reactor has been found numerically and one of the most significant parameters is found to be the porosity of the reactor bed. This result is experimentally validated using a small-scale thermochemical reactor setup. An FVM based analysis is performed for the hydration reaction (energy release) of MgSO4 salt in a packed bed reactor with continuous flow of moist air through the bed. Numerical analysis reveals that the parameters such as porosity of the packed bed, flow rate of moist air across the reactor vessel, particle diameter of the salt, concentration of water vapor at inlet, and heat capacity of the reactor wall, play an important role on the performance of the energy storage system. In experimental analysis the effect of porosity of the reactor bed is analysed and the results shows a good agreement with the numerical prediction. Key Words: Thermal storage, Adsorption Kinetics, thermo-chemical material, Packed bed reactor, MgSO4