International Journal of Thermofluids (Feb 2023)
Numerical modelling of heat accumulator performance at storage of solar energy
Abstract
One of the main tasks in designing heat accumulators for renewable energy installations is accurately calculating the temperature and energy intensity of the heat accumulator. In recent years, based on the use of modern technologies, it has become possible to obtain building materials with high characteristics of the heat-accumulating medium. In order to increase the efficiency and reliability of heat accumulators, as well as the optimal choice of elements for building structures, there is a need to improve methods for calculating their operating modes based on the creation of numerical models. The article considers the principles of creating heat accumulators based on various heat storage media. Based on the system of differential equations of motion of the coolant and thermal conductivity, a mathematical model of the solar heat accumulator is constructed and a program for its numerical solution is developed. The fields of temperature distributions inside an underground heat accumulator with different warm-up times were obtained and the average daily temperature of the working fluid of the heat accumulator based on gravel and zeolite was determined. It is shown that in comparison with a gravel accumulator, the energy efficiency of a zeolite is twice as high, and the volume of the chamber of a zeolite accumulator can be twice as small as a gravel one with the same efficiency of its operation. Recommendations are given on the selection of various heat storage materials, with an assessment of their applicability and availability. The subject of research: methods for calculating the temperature and energy consumption of elements of building structures of heat accumulators. Objectives: improvement of methods for calculating the temperature and energy consumption of building elements of heat accumulators. Materials and methods: the proposed method is based on the possibility of creating a numerical model of a heat accumulator heated by solar radiation to simulate the dynamics of changes in the average temperature of the heat accumulating material over time. Results: A theoretical calculation of the temperature and energy consumption of the heat accumulator is proposed. Conclusions: the approach proposed in this article can be applied to energy construction.
