Modelling of Oil Based Medium Temperature Sensible Heat Thermal Energy Storage Systems During Charging
Abstract
A simulation model for oil based medium temperature sensible heat storage systems for domestic solar cooking applications is developed and validated with experimental results. The simulated and experimental results are simultaneously compared for three sensible heat storage systems during charging. The three systems compared are a Sunflower Oil only storage tank, a Sunflower Oil/10.5 mm pebbles packed bed storage tank and a Sunflower Oil/31.9 mm pebbles packed bed storage tank. The packed bed TES systems have void fractions of 0.39 and 0.43, respectively. A forward finite difference model is developed in Matlab to simulate the storage systems. Validation of the thermal energy storage (TES) models is done using a flow-rate of 4 mls-1. A good level of agreement exists between simulated and experimental results with an overall mean percentage error (deviation) of 6 % for the Sunflower Oil/31.9 mm pebbles packed bed storage tank. The effect of the charging flow-rate, inlet charging temperature, thermal oil and solid storage material is investigated with the model.