Operating Point Analyses for Solid Oxide Fuel Cell Energy Systems

摘要

The successful design of fuel cell systems requires proper selection of stack operating conditions. Studies focusing on optimal operating point selection have only recently emerged. The operating point of the fuel cell in terms of performance variables, such as fuel utilization, operating voltage, and area specific resistance, will dictate the power density and operating efficiency of the stack module. In turn, establishment of these performance parameters enables a determination of capital, fuel, and electricity costs for a given utility requirement. The choice of the relevant performance parameters may maximize electric power, or electric efficiency. In this paper, optimal operating point analyses are performed for the purposes of establishing a system design through constrained optimization of the cost of electricity for an advanced planar solid oxide fuel cell system employing indirect internal reforming and anode gas recirculation. Sensitivity analyses of economic and cell performance parameters on operating point selection are presented. The system performance parameters varied include operating cell temperature, cell voltage, fuel utilization, and excess air. The sensitivity to variation of fuel and stack cost parameters is also presented. These analyses are important not only as design guides, but also in providing a framework for establishing system operating and control strategies for building integrated solid oxide fuel cell applications.