Influence of Energy Recuperation on the Efficiency of a Solid Oxide Fuel Cell Power System

Abstract

In this paper, the influence of energy recuperation on the efficiency of a solid oxide fuel cell (SOFC) power system is studied with the GCTool software developed by the American Argonne National Laboratory (ANL). The recuperative energies include partial recycled air exhausted from cathode side, recirculated fuel and steam from the anode side of the SOFC, and combustion gases from anode exhaust, individually. The methane is chosen as fuel, air is oxidant, and the pressure drops due to streams transported through the duct and components are taken into account in the power system. Full analysis of the state at each node of the system is conducted. The results show that, under the same setting, with an A/F of 4, a pre-reforming rate of 30%, and fuel utilization of 80%, the overall system efficiency is elevated from 50 to 68% in the case of recirculating partial fuel and steam from the anode exhaust of the SOFC. And, the configuration of diluted fuel recycled entirely from the outlet of the anode side of the SOFC is going to cause the overall efficiency to become the lowest in all cases in spite of reaching the highest electric efficiency of 41%. Recirculating partial air released from the outlet of the cathode side could provide extra heat to preheat inflow air, and the overall efficiency will be raised, apparently, as well.

Experimental investigation of 1kW solid oxide fuel cell system with a natural gas reformer and an exhaust gas burner

“…Santangelo and Tartarini [4] compared the fuel consumption characteristics of fuel cells and traditional power generation systems and suggested that fuel cell devices provided the potential for developing CHP systems for residential and industrial applications with virtually complete energetic independence. Chung et al [5,6] investigated the effects of energy recuperation on the efficiency of a SOFC and showed that the overall system efficiency could be increased from 50% to 68% by recirculating the partial fuel and steam from the anode exhaust of the SOFC.…”

A Comprehensive Review of Thermal Management in Solid Oxide Fuel Cells: Focus on Burners, Heat Exchangers, and Strategies

“…They found that the system's performance varied significantly under different modes, with the homogeneous charge compression ignition (HCCI) mode yielding the best results. Chung and colleagues investigated the impact of energy recovery on SOFC efficiency [151]. They supplied the high-temperature unreformed fuel directly from the SOFC to the afterburner and improved overall system efficiency from 50% to 68% by partially combusting anode exhaust gas and recycling steam.…”

Investigation of Economical Design Strategies for the Solid Oxide Fuel Cell Afterburner Based on Computational Fluid Dynamics Simulation

“…Several researchers proposed both the mechanical design and catalytic combustion burners. , In addition to burner design, studies on SOFC process design considering the afterburner influence were also conducted. For example, Chung et al investigated the benefits of fuel recirculation using an afterburner, and their results showed that recirculating partial fuel and steam from anode-off-gas can increase the overall system efficiency by around 36% . Moreover, several simulation studies analyzed dynamic correlations among the afterburner, stack, heat exchanger, and reformer and explored optimal operation ways of the SOFC system with an afterburner. − …”