Optimized design and operation of heat-pipe PV-T system with phase change material for thermal storage -

Abstract

This work aims to study performance of a heat pipe photovoltaic-thermal (HP-PV-T) panel integrated with phase change material (PCM) thermal storage water tank to produce electricity and hot water for an office building. A transient mathematical model for the HP-PV-T was developed to predict its performance at given PCM melting point. The model predicted the PV panel temperature, electrical power output and hot water temperature. The model was validated experimentally using PCM at 29ºC melting-point in Beirut climate during the month of July. The validated model was applied on a typical office space in the city of Beirut to obtain optimal design using a derivative free genetic algorithm. The incremental system cost associated with heat pipe and PCM tank was used in the optimization to obtain the design resulting in minimum annual auxiliary heating cost to meet hot water demand while providing the electricity needs at lower number of PV panels due to improved PV efficiency. An optimal system of 4 kW (20 PV panels each at 1.6 m²) was found to meet the electric power needs all year round. The optimal PCM storage tank size per panel was 37 liter at PCM total mass of 22.42 kg with melting temperature of 33ºC.