Energy losses study in solar hybrid gas turbine in Colombia

Abstract

Due to decrease of oil reserves, the international commitment for the reduction of pollutant emissions and environmental protection, renewable energy sources are intensively studied, including solar energy applications. However, solar energy is not constant and one possible alternative are solar hybrid thermosolar power plants. A hybrid solar gas turbine has three subsystems: a solar concentrator with heliostat field and central tower receiver, a combustion chamber, and a regenerative gas turbine. A previous thermodynamic analysis allowed shows an energy and exergy study of the plant, from a thermodynamic model of the system that has a method of solar resource estimation. However, this analysis did not allow evaluation of the energy losses in the system components, although the original model considered the typical irreversibilities of these cycles. This work aimed to develop a thermodynamic model that estimates the energy losses in the subsystems and the solar hybrid gas turbine components from a few parameters. The model estimated the energy losses for a Brayton cycle hybrid solar thermal plant throughout the day July 20 in Barranquilla, Colombia. A Dymola compiler in Modelica language was used to evaluate the model, which facilitates the estimation of the results at different times of the day. In this case, the computations were performed hourly throughout the day. In the results, energy losses were 16 % in the solar concentrator when the solar resource was the maximum at noon and close to 1 % in the combustion chamber. Therefore, the hybrid solar Brayton cycle system is technically feasible and reduces fuel consumption. Consequently, it is important to continue developing concentration systems and reduce their energy losses