Analyse thermoeconomique d’un système de stockage de Carnot

Abstract

Energy is today an essential factor in the development of society. However, fossil energy sources remain the main source of meeting the growing demand for energy. Knowing this, these energy sources cause significant environmental pollution problems. This is why the world must move towards renewable energies. On the other hand, energy storage constitutes a major problem for the evolution of renewable energy production. As solutions, Carnot battery systems are a new method of large-scale energy storage, which stores electricity as heat in a thermal reservoir using a heat pump and recovers this heat using using a heat engine. A low-temperature Carnot battery (BC) numerical model based on the organic Rankine cycle was simulated by MATLAB software. Energy, exergy and economic (3E) models of the BC system were built. The levelized cost of storage (LCOS) is used as the objective function and the thermal storage temperature as the optimization parameter. With a thermal storage temperature increasing from 90◦ C to 130◦ C, the value of the levelized cost of storage gradually decreases from 0.236 FCFA/kWh to 0.163 FCFA/kWh. The power-to-power efficiency continuously decreases with increasing thermal storage temperature, however, the variation of exergy efficiency with thermal storage temperature is decreasing. A maximum value of 26% is reached when the thermal storage temperature is 90◦ C. Furthermore, it can be seen that the value of the levelized cost of storage gradually increases with the improvement of energy efficiency. The cost and exergy destruction of each component are also evaluated