Analysis of the effects of use of thermal energy storage device (TESD) in solar air heater

Abstract

In this research work a setup is designed to incorporate Lauric acid as a phase changing material (PCM) in a solar air heater. This phase changing material (PCM) is carefully selected based on the application and manufacturing constraints. A thermal energy storage device (TESD) is manufactured and incorporated in solar air heater and experiments were carried out to compare the solar air heater with and without thermal energy storage device (TESD) to evaluate various parameters such as output temperature and pressure drop. Results revealed that the rise in the output air temperature decreases from 8.67K to 4K with the increase in the mass flow rate of air flowing through the solar air heater from 0.021kg/s to 0.035kg/s. Also with an increase in the mass flow rate, there is a decrease in the friction factor from 0.0119 to 0.00802. There is an average increment of 86.47% in the rise of output air temperature with TESD as compared to rise of the output air temperature without TESD with an average increment of 36.47% in friction factor. A computational analysis is also performed which gives insight into the working of solar air heater with thermal energy storage device (TESD). A computational domain of solar air heater with TESD is analyzed in CFD code FLUENT using various turbulence models such as k-ω SST, k-ω Standard, k-∊ Standard and k-∊ RNG. It is observed that results obtained from turbulence model k-є RNG model are in good agreement with the experimental results and hence used for the analysis of all the cases considered in this work.