Performance Analysis of Especially Flow Design Heat Exchanger used in Hybrid Solar System

Abstract

Solar Photovoltaic (SPV) module converts the light component of solar radiation into electrical power. The heat component of radiation absorbed by module increases its operating temperature. Due to this, the electrical efficiency of modules drops by 10-35%. By maintaining operating temperature of module at 25°C extracting its heat using external cooling system; module can produce rated electrical power efficiently. The cooling system attached at bottom of module is called as PV heat exchanger, which produces thermal power in terms of hot water. Combined PV module and heat exchanger generating both electrical and thermal power is called as hybrid Photovoltaic/Thermal (PV/T) solar system. A especially flow design heat exchanger called as spiral flow PV absorber and its effect on performance of hybrid PV/T system is studied in this paper. The experimental results like performance efficiencies of Photovoltaic, thermal and PV/T system over a range of working conditions were discussed and evaluated for latitude of Mumbai. The final results at solar radiation of 892 W/m² and water mass flow rate of 0.042 kg/sec through heat exchanger showed combined PV/T efficiency of 68.2 % with PV efficiency of 12.9 % and performance ratio of 80 %. Recommendations for enhancing the performance of hybrid system further are also included in the discussion section of the paper.