Off-Design Analysis of a MCFC-Gas Turbine Hybrid Plant

摘要

The paper presents a model for the off-design analysis of a hybrid plant based on anMCFC and a gas-turbine. The model is used to define a possible regulation strategy fornthe power plant, minimizing the performance decay at partial load and allowing investigationnof the interaction issues among the different plant components. The hybrid plantnreflects at nominal conditions the expected performances for the 500 kW-class MCFCnplant proposed by Ansaldo Fuel Cells. The simulation is carried out respecting thenmatching of the gas-turbine and the part-load behavior of the fuel cell and the heatnexchangers. The gas-turbine is modeled through compressor and turbine performancenmaps, and the FC is modeled through a finite volume code. The results indicate thenpossibility to regulate effectively the plant power output acting on the turbine shaft speed,nthe air-to-fuel ratio, the bypass of cathode air, and the fuel utilization, achieving verynhigh part-load efficiency and respecting constraints on the admitted operating range fornthe plant components.