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.
