Dynamic characteristics of a solid oxide fuel cell with direct internal reforming of methane. (1st April 2016)

• Record Type: Journal Article
• Authors: Ho, Thinh X.
• Is Part Of: Energy conversion and management. Volume 113(2016)
• Page Start: 44
• Page End: 51
• Publication Date: 2016-04-01
• Subjects: Dynamic modeling -- Transient -- SOFCs -- Internal reforming; Direct energy conversion -- Periodicals; Energy storage -- Periodicals; Energy transfer -- Periodicals; Énergie -- Conversion directe -- Périodiques; Direct energy conversion; Periodicals; 621.3105
• DOI: 10.1016/j.enconman.2016.01.049
• Languages: English
• ISSNs: 0196-8904

Abstract

Highlights: Transient operation of an SOFC with direct internal reforming is investigated. A 3D, non-isothermal numerical model is employed. Jumps (up and down) of the output voltage are introduced to the cell. Various temporal profiles (cross-sectional, lateral and lengthwise) are presented. An activation overshoot is seen in the exit region, not in the sub-cooling region. Abstract: An analysis of a solid oxide fuel cell (SOFC) working with direct internal reforming of methane when subjected to unsteady conditions is presented in this paper. A cell of planar type with the anode-supported structure and the co-flow configuration is investigated. Owing to the reforming and the water–gas shift reactions, it has been known that the steady operation of a cell working with natural gas is different from that with hydrogen. Moreover, since these chemical reactions are strongly temperature-dependent, the former is expected to become much more complex than the latter under unsteady states. It is necessary in the viewpoints of degradation and performance efficiency to understand the evolution of the thermal gradient/stress, the fuel concentration, etc. when the cell is subjected to changes such as load demand. In this work, a three-dimensional numerical model is employed and step changes of the output voltage are introduced to the cell. Results for the temporal profiles of the temperature, the current density, the activation overpotential and the gas concentration distributions in the cell are presented and discussed. It is found that the overshoot in the activation does not appear throughout the cell, but only in the exit region when the voltage jumps from 0.7 V to 0.6 V.