Discharging simulations of a thermal energy storage (TES) system for an indirect solar cooker

Models for an oil/pebble-bed thermal energy storage (TES) system and the thermal energy utilization (TEU) system of an indirect solar cooker are used to perform discharging simulations. The model is validated with experimental results and reasonable agreement is obtained between simulation and experiment. Deviations between experiment and simulation are accounted for by factors such as mixing effects and mass diffusion. Discharging results of the TES system are presented using two different methods. The first method discharges the TES system at a constant flow-rate while the second method varies the flow-rate in order to maintain a desired power at a constant load inlet temperature. The results of discharging the TES system at a constant flow-rate indicate a higher rate of heat utilization. This is not beneficial to the cooking process since the maximum cooking temperature is not maintained for the duration of the discharging period. On the other hand, the controlled load power discharging method has a slower initial rate of heat utilization but the maximum cooking temperature is maintained for most of the discharging process and this is desirable for the cooking process.