Study on supercritical CO2 coal-fired boiler based on improved genetic algorithm

Abstract

Supercritical CO2 coal-fired power generation technology is a new potential power generation technology due to its advantages of high efficiency, simple system and less carbon emission. In this study, a new global optimization model was designed with an improved genetic algorithm to optimize the supercritical CO2 boiler and evaluate its economy, aiming at levelized cost of energy (LCOE). Besides, the weighted mass method and thermodynamic calculation were adopted to accurately evaluate the cost of supercritical CO2 boiler. According to the optimization results, the heat absorption distribution and triangular distribution for the tube diameters of supercritical CO2 boiler from the furnace to the tail flue were given. The economic analysis of supercritical CO2 unit shows that the LCOE of empirical unit decreases by 9.26% compared to the conventional unit, and the optimized unit further decreases by 1.13%. In the cost of supercritical CO2 unit, the cost of boiler, recuperator and precooler is higher than that of the conventional unit. And the increased cost of heating surfaces at tail flue mainly accounts for the increased equipment cost of boiler. Finally, the sensitivity analysis shows that the regions that has high coal price is more suggested for the development of supercritical CO2 unit, and the unit also has excellent economic advantages under low load condition.