Thermodynamic Modeling and Analysis of the Ratio of Heat to Power Based on a Conceptual CHP System

Abstract

The CHP system not only produces electrical energy, but also produces thermal energy. An extensive analysis of the CHP market reveals that one of the most important engineering characteristics is flexibility. A variable heat-to-power ratio has compelling advantages over a fixed one and enables a power plant to achieve reliability and flexibility, which are very important characteristics for a CHP system. In this paper, a conceptual SOFC/GT CHP system is presented. The parameters' effect on the variable heat-to-power ratio is investigated. As SOFC reactors are still under development, a flexible simulation tool based on mass and energy balances coupled with appropriate expressions for the reaction kinetics, thermodynamic constants and material properties, is presented for adaptation to different cell geometries and operating conditions. Simulation results show that the SOFC/GT CHP system's advantage over the engine is that a low stack running temperature can achieve a low heat-to- power ratio.