Numerical analysis and performance assessment of the Thermal Energy Storage unit aimed to be utilized in Smart Electric Thermal Storage (SETS)

Abstract

Used on a wide scale Electric Thermal Storage (ETS) is one of load balancing method for the electrical power system. ETS is the technology of converting off-peak electricity into heat and using it in household heating 24 h a day. Since the thermal energy is stored in the bed during off-peak hours, and while discharged during peak hours, it results in significant savings in the household heating cost. In the study, the principles of ETS central heating system operation are presented. The proposed ETS central heating system is suitable for Smart Electric Thermal Storage (SETS) when connected with an appropriate charging control system. As the central part of the study, a numerical model of the ETS discharge is presented. The proposed two–dimensional model takes into account the transient temperature distribution within the considered geometry. The governing system of differential equations along with boundary and initial conditions are solved using a Finite Volume Method. The accuracy of the author's code is assessed along with the analytical solution, as well as Ansys Transient Thermal. Furthermore, numerical results are compared with experimental data of the ETS central heating system operation. After the numerical model validation, calculations of the ETS unit performance are carried out including flow distribution, heat transfer coefficients, and heat flow within the system. A preliminary analysis of the operating parameters, the initial air temperature and the air velocity, as well as construction of the ETS unit, on the system performance is also presented.