Design and Optimization of PCM integrated Solar Water Heating System: Case Study Limmu Gennet Hospital

Abstract

Solar energy is abundant renewable energy available everywhere, environmentally friendly and easily harnessed, and used for domestic and industrial water heating ap plications. Since this energy is alternating, a thermal energy storage system is required to store the energy for later use. Many authors optimized TES (K. Kumar et al., 2021) (Karuthedath et al., 2020). However, they did not consider the effects of the inlet design of a HWT to store large amounts of energy. In this study, the diameter and height of the HWT were calculated from the total volume of hot water required for the hospital which was found to be 38.88m 3 Using this volume, height and diameter of HWT are 4.64m and 2.32m. A total volume of 5.8m 3 PCMs was designed and integrated into latent Shell and tube TES by modeled Solidworks2020. The site solar energy analyzed from 2017 to 2021 collected from Jimma Metrology Agency temperature of cold and hot water was 295K and 375K, respectively. In this work, three models of HWT were stud ied with different inlet designs to optimize HWT and enhance the thermal stratification of hot water tanks. Model 1 was designed with an ordinary inlet pipe, while model 2 was perforated. However, in model 3, holes were used as inlet and outlet. A detailed simulation was performed by ANSYS FUENT 19.2 independently for each model with the same mass flow rate of 1.31 kg/s and inlet temperature of cold and hot water 295K and 375K, respectively. CFD result indicated that efficiency of model 2 was improved from 53.1% to 56.2% compared to model 1 and 49.9% to model 3. In model 1, around six layers are seen; in model 2, only one layer is observed.