Packed bed is generally recommended for attaching with solar air heater in order to store thermal energy of hot air. For designing such a system under the given system and operating parameters, it is required to predict performance of the system by using mathematical models. In the present paper an attempt has been made to discuss mathematical models reported in the literature for predicting thermal performance of packed bed energy storage system for solar air heaters. The designer may be benefited from the consolidated information reported in the present paper.

Simulated performance of packed bed solar energy storage system is reported in the present paper in continuation with Part-I and Part-II of this paper. The present part of the paper deals with system performance w.r.t. energy consumption by fan to propel air through the bed and thermal efficiency of solar collector. It is observed that energy consumption by fan and thermal efficiency of the collector are strong function of system and operating parameters.

Abstract:In the present paper an attempt has been made to report simulated performance of a packed bed solar energy storage system. Performance of the system having large size storgae material elements has been evaluated as a function of system and operating parameters. In the present part of this paper, system performance w.r.t. temperature distribution in the bed, thermal energy stored and available energy stored in the bed have been reported and discussed. It is observed that the system parameters play a predominant role to influence heat transfer characteristics of packed bed solar energy storage system.

Abstract:Major concern for design of a packed bed solar energy storage system is to maximize heat transfer during charging and discharging phase by spending minimum amount of pumping power. Shape of the material elements and void fraction of the bed are the system parameters for a given material size, which could affect heat transfer and pressure drop in the bed considerably. In the present study, simulation has been carried out to evaluate optimum values of system parameters in order to have the best thermo hydraulic performance of packed bed solar energy storage system. Five different shapes of large size material elements have been analyzed to carry out the present optimization study. In order to select optimum values of system parameters under the given operating conditions, design plots have been prepared and presented in the paper.