Solver Convergence of IGFC Process Simulation

Integrated Coal Gasification Fuel Cell Combined Cycle (IGFC) is expected to be the most efficient power generation system in coal fired power generation systems [1,2]. We have been analyzing the processes of Advanced IGFC (A-IGFC) [3] which is expected to be realized in 2040. The Advanced IGFC (A-IGFC) system can reduce the exergy loss resulting from combustion, and its ‘exergy recuperation’ [4] is appealing. The waste heat exhausted from the fuel cells is recycled to the gasifier for steam reforming in an endothermic reaction with a low exergy loss and a high cold gas efficiency. Our current study focuses on the optimization of the unit configurations of the A-IGFC including gasifier, compressor, solid oxide fuel cell (SOFC), combustor, gas turbine, heat recovery steam generator (HRSG), and steam turbine. The process simulator HYSYS®.Plant (Aspen technology Inc.) is employed in order to express the gasifier, the SOFC and the other units. The process of reforming with steam means recycled steam stream in the HYSYS® model. In the previous study [3] we found that many recycled material streams and recycled steam in the AIGFC process prevent convergence of solver. It is shown that comparison of simulation program, a trial analysis of the AIGFC process using HYSYS.Plant and the problems about convergence of solver.