Modeling of Reformers for Fuel Cell Applications

The lack of an existing hydrogen infrastructure makes fuel processing of hydrocarbon fuels a critical component of fuel cell systems. The reformer is the principle reactor in the fuel processing subsystem and converts various hydrocarbon fuels into hydrogen, carbon monoxide, and other products that can then be utilized in the fuel cell. To help understand and quantify diesel fuel reforming by partial oxidation, a computational fluid dynamic model was developed that included the following sub-processes: liquid fuel atomization, fuel drop evaporation, fuel drop boiling and vaporization, and gas-phase chemical reaction. This work focused on n-heptane as a representative diesel fuel and reduced reaction mechanisms from the literature for fuel rich oxidation of n-heptane were used to analyze reactions in the partial oxidation reformer. Turbulent chemistry was modeled using the eddy dissipation concept. Reactor performance and parametric analysis based on model simulations are presented and discussed.