NOVEL TECHNIQUE FOR MAXIMIZING THE THERMAL EFFICIENCY OF A HYBRID PV/T SYSTEM USING PULSE WIDTH MODULATION

Abstract

In this paper a comparison between numerical model and experimental work results for a fixed Photovoltaic/ Thermal (PV/T) hybrid system is presented. The simulation in this work is based on a numerical model in solving the equations and determining the Photovoltaic (PV) cells thermal characteristics using both MATLAB and COMSOL Multiphysics. COMSOL is simulating the electromagnetic waves produced by the Sun through solving Maxwell's equations in three dimensions using Finite Elements Methods (FEM) and the sun irradiance is assumed to be Gaussian distribution across the twelve mourning hours. Beside that an experimental work is presented depending on the results conjured from the theoretical experience used in Comsol Multiphysics. A Pulse Width Modulator (PWM) is used to control the solenoid valve operation. In addition to the above a thermal analysis for the fixed PV modules and the piping water is presented where the output water temperatures, rate of heat transfer, overall heat transfer coefficient and thermal efficiency are calculated. As a result, a significant enhancement in the total thermal efficiency is observed with acceptable increase in the output water temperature.