Simulation research on optimization of a 200 MW IGCC system

Abstract

The integrated gasification combined cycle (IGCC) has increasingly attracted attention as a promising high-efficiency clean coal technology. The oxygen-to-carbon ratio (O/C), nitrogen reinjection coefficient (X_gn), and integration air separation coefficient (X_as) affect system performance greatly. Based on the selected coal type, this paper establishes a 200 MW IGCC system model with coal–water slurry gasification, matches the three-pressure reheating heat recovery steam generator and syngas coolers, simulates and calculates the system performance of O/C, X_as and X_gn using Thermo-flex software. From the perspective of the whole system, the optimal O/C of the system is obtained as 0.91 considering the syngas composition and gasification temperature. From the perspective of system efficiency, the X_gn is obtained as 60 % with the X_as of 20 %. The overall IGCC system model is optimized using the optimized O/C, X_gn, and X_as to obtain higher system power and efficiency, the system power generation efficiency can improve up to 51.52 %. A thermal balance diagram of the IGCC system is drawn using the calculation results and provides a reference for the future design and operation of IGCC systems.