Near-Optimal Controls of a Fuel Cell Coupled with Reformer using Singular Perturbation methods

Spiral Methanol to Hydrogen Micro-Reformer for Fuel Cell Applications

Water-balance Assessment in a Reformer/Fuel-cell System

Abstract. In PEM fuel cells pure hydrogen is used as a fuel. Due to its low density, the density of its stored energy is low, too. One of the possible solutions to the problem is production of hydrogen from the energy-reach material, e.g. methanol. Conversion of methanol to hydrogen is made with reformer in a steam reforming process in which besides methanol there is also water needed. On the o...

Singular perturbation near mode-coupling transition

We study the simplest mode-coupling equation which describes the time correlation function of the spherical p-spin glass model. We formulate a systematic perturbation theory near the mode-coupling transition point by introducing multiple time scales. In this formulation, the invariance with respect to the dilatation of time in a late stage yields an arbitrary constant in a leading order express...

A Compact Reformer for Portable Fuel Cells

A compact reformer to generate hydrogen for portable fuel cell applications is presented. This reformer is a conventional type single-path tubular reactor packed with granular catalyst particles in which steam reforming and catalytic partial oxidation reactions take place in series using a mixture of methanol and water as a feed. The novel feature of this reformer is in the interlacing of the f...

Applications of Singular Perturbation Methods in Queueing

A survey is presented describing the application of singular perturbation techniques to queueing systems. The goal is to compute performance measures by constructing approximate solutions to specific problems involving either the Kolmogorov forward or backward equation which contain a small parameter. These techniques are particularly useful on problems for which exact solutions are not availab...

Solution of reduced equations derived with singular perturbation methods.

For singular perturbation problems in dynamical systems, various appropriate singular perturbation methods have been proposed to eliminate secular terms appearing in the naive expansion. For example, the method of multiple time scales, the normal form method, center manifold theory, and the renormalization group method are well known. It is shown that all of the solutions of the reduced equatio...