MATHEMATICAL MODEL OF COGENERATION ENERGY COMPLEX WITH SOLAR RADIATION CONCENTRATION

Abstract

Abstract. Based on the results of testing linear photovoltaic modules (Λ-PM) with optical concentrators, as well as studies on heat transfer in channels with heat-generating photovoltaic cells on the walls, a new type of equipment has been developed — an energy complex with Λ-PM and a cooling system. In this system, the technological contradiction caused by the decrease in the electrical efficiency of silicon photovoltaic cells with increasing outlet water temperature is reduced. To achieve this, half of the photovoltaic cells operate at a relatively low temperature (< 40^◦C) to maintain sufficient efficiency, while the other half work at a high temperature (≈ 70^◦C), generating, in addition to electricity, highpotential thermal energy. As a result, the total performance in terms of electricity and heat equals the overall performance of a standard PM with the same concentrator aperture area, moreover, high-potential heat is produced for hot water supply. A mathematical model and a methodology for calculating the output characteristics of the energy complex are presented, based on the thermal energy balance in the Λ-PM channels with mutual shielding of thermal radiation from the frontal walls. Using a Python-based software application, iterative calculations of water temperature and flow rate, as well as the specific electrical and thermal power of the energy complex, were performed.The results demonstrate a significant advantage of the developed cogeneration technology compared to known analogues. Through numerical experimentation, the reliable removal of heat from the surface of Maxeon-type silicon photovoltaic cells under natural water circulation in the cooling system in the laminar viscous-gravitational flow regime was demonstrated. With the help of the software application, computer simulations were carried out to forecast the performance of the energy complex in regions with different solar resources.
Keywords: linear photovoltaic module, optical concentrator, cooling system, circulation loop, heat transfer coefficient, mathematical model, thermal efficiency