Experimental analysis of wet gas-liquid water mixture within the tank of water in glass evacuated tube solar water heater

Abstract

ABSTRACT In this investigation, thermal performance characteristics of passive solar water heater with vacuum tube were experimentally studied by using the mixture of wet gas and liquid water. Five different outlet locations of the tank were used to produce five different proportions of wet gas-liquid water mixtures. Experimental results were proposed in the way of water temperature, gas temperature, thermal stratification number, temperature distribution zone and a correlation for thermal efficiency through wet gas proportion. It was concluded that the wet gas-liquid water mixture at a wet gas proportion of 70% ameliorates the water temperature and thermal stratification number by respectively 13.7°C and 10.33 times compared to the mixture at a wet gas proportion of 10%. For different wet gas-liquid water mixtures, temperature distribution zone shows a quadratic parabola. The correlation for thermal efficiency through different proportions of mixtures presents the regularity of linear regression equation. Also, the average R2 and average Root Mean Square Error (RMSE) of regression analysis correlation are calculated as 0.936 and 0.375, respectively. The novelty of this work is evaluating the effect of different proportions of wet gas-liquid water mixture on the thermal performance and thermal stratification of passive vacuum tube solar water heater, and develop a correlation for thermal efficiency through different proportions of mixture.