Transient modeling and simulation of a solid oxide fuel cell

Solid Oxide Fuel Cells (SOFC's) are a highly efficient, environmentally benign method of electric power production. SOFC systems have been proposed for electric utility power generation in both large central station power plants and distributed generation stations. SOFC modeling for utility applications has focused on steady state electric power generation. More recently, SOFC's have been proposed as power sources in electric drive systems for transportation applications. In transportation, transient and partial load operation predominate. In order to continue the development of SOFC's for transportation, the transient operation of SOFC's must be understood and modeled.; This work describes the development of a computer model for simulating the transient operation of a tubular solid oxide fuel cell. The model includes the electrochemical, thermal, and mass flow elements that affect SOFC electrical output. The electrochemical and thermal parts of the model were developed and tested separately before they were combined to form the transient model. This approach assured that the major components of the transient model were functioning properly before they were incorporated into the large combined model.; The transient model was tested under conditions similar to those published for a planar SOFC model. The newly developed transient model for tubular SOFC's showed the same general response and trends as the previous planar model. Additional simulations were conducted under conditions more relevant to tubular SOFC systems. The new model can provide both steady state operating points and the cell transient response in moving between them. This is a significant advantage over previous steady state models for tubular SOFC's, and is the major contribution of this work. None of the previously published tubular SOFC models addressed transient operation of the cell.