This paper studies the influence of the high-temperature solar preheating system and chemical recuperation system on the overall performance of a MW-level three-shaft gas turbine. In order to obtain accurate simulation results, this paper adopts an integrated simulation method, where the simulation models of the solar receiver and gas turbine are established on the Matlab/Simulink platform, the simulation model of the chemical recuperation system is established on the Aspen Plus platform, and the interface between Matlab and Aspen Plus is developed for mutual communication. With the component maps, the Newton-Raphson iteration method is used to solve the thermodynamic performance of the gas turbine.
Based on the above simulation models and solution method, the effects of the mean receiver wall temperature (Ts) and steam-to-methane ratios (R) on the overall performance of the gas turbine are studied in this paper. From the perspective of safe operation, the influence of Ts and R on the net output power of the gas turbine is first calculated. The results show that in the safe operating range, chemical recuperation can significantly increase the net output power of the gas turbine, while the net output power increases first and then decreases with the increase of Ts. When the output power is constant, increasing Ts or R both can effectively reduce fuel consumption, and increasing R can also improve the heat recovery efficiency and the overall thermal efficiency. However, the heat losses of the receiver increase as Ts increasing, meanwhile, the heat recovery efficiency and the overall efficiency also decrease gradually. Therefore, in actual operation, various factors should be taken into account in order to reduce fuel consumption and improve the overall thermal efficiency.