First and second law performance variations of a coal gasification fuel-cell-based combined cogeneration plant with varying load

Abstract

An advanced combined cogeneration plant based on a solid oxide fuel cell (SOFC) stack, fuelled by synthetic gas by coal gasification, upstream of a gas turbine and heat recovery steam generator (HRSG) to generate power as well as process steam downstream of it, has been thermodynamically modelled. While the plant supplies a base load power and process heat, provision of a fuel cell bypass mechanism for the synthetic gas stream offers the flexibility of matching the varying electrical power or the process heat load on the plant. The simulated energetic and exergetic performance of such a plant is presented in this paper and the optimum point of operation is reported. The exergy analysis shows the second law performance variation of significant components of the plant with varying loads.