An Investigation Of a Solar Water Heater Using a Double-Walled Absorbent Spherical Tank and Solar Gravity For Thermal Operation

Abstract

This study explores innovations in solar water heating systems through two key approaches. In the first stage, a spherical, double-walled thermal storage tank integrated with phase change materials (PCM) was designed to enhance both solar energy capture and thermal insulation, achieving a maximum temperature of 80.3°C and 74% thermal efficiency, sufficient for 8.43 individuals. In the second stage, the use of graphene/water nanofluids was investigated to improve the efficiency of solar gravity heat pipes. Results showed that incorporating 0.05 wt% graphene nanofluids reduced startup times by 15.1% and 10.7%, indicating enhanced thermal performance and efficiency in solar energy collection.