Transient heat transfer analysis of serially connected array of phase change material in the thermal battery units with Al2O3 working Nano fluids

This study is focused on heat transfer analysis of a serially connected PCM thermal battery units where Al(2)O(3 )based Nano fluid is circulated inside u-tube at every battery storage tank. The most stable Crank-Nicolson numerical shame is applied to set of equations which are derived based on energy balance governing equation and a thermal capacitance network from borehole heat exchanger concept. Transient thermal performance of the PCM material such as hourly variation in mean temperature of the PCM material inside the thermal storage batteries as well as temperature profile of the PCM material along the depth of the tanks are determined at different time period. Additionally, temperature profile of the working fluid along the depth of the storage tank as well as hourly temperature variation of the Nano fluid at exit of different tanks are presented in the study.