Michel Dostie

Optimal control and CFD modeling for heat flux estimation of a baking process

Abstract An optimal control method was combined with commercial CFD software for the optimization of heat flux during a baking process. The objective function was defined in terms of the transient heat flux, the temperature and the humidity of the baking product. The optimal control was achieved by the conjugate gradient method. The minimum energy consumption for a desired final baking product temperature and humidity was estimated. This study confirmed the relationship between the heat flux and baking product quality attributes and showed that optimal control models represent reliable tools to support decision making for complex processes such as baking. The proposed optimal control approach is general and could be easily extended to other processes.

Power Transfer Analysis in a Utility-Interconnected Fuel Cell Distributed Generator

Distributed generation (DG) is increasingly used as a means of satisfying the growing need for electric energy. The interest in DG is the result of the opening of the energy markets under deregulation and of recent technological advances in mechanical, electrical and power electronics conversion systems. Among DG systems, much attention is focused on environmentally friendly fuel cells, photovoltaic and wind generators. This paper presents active and reactive power transfer analysis when a fuel cell DG system is connected to a utility distribution network. Influences of the line impedance, DG output voltage magnitude and phase angle, and grid-connected inverter control method, are investigated by theoretical analyses. The relationship between output voltage phase angle and hydrogen flow is also presented. The interconnected power transfer study is supported by simple Matlab/Simulink models to validate theoretical analyses