Fehd Ben-Aicha

Diesel Particulate Filter Thermal Management Using Model-Based Design

Diesel Particulate Filters (DPF) are now considered as efficient solutions to reduce Diesel PM emissions. Concerned by environment, Renault will equip all serial production Diesel vehicles with this technology. The main issue for these devices is the periodical regeneration necessary to eliminate the accumulated soot. The challenging enhancement of the regeneration event can be achieved with a better regeneration temperature control. For this purpose, a controller based on a physical model is proposed to manage the DPF temperature during active regeneration. This paper describes the methodology which has been followed to design this controller. In a first step, a reduced physical model has been developed and validated with experimental data. In a second step, two model-based controllers have been studied: a robust LPV (Linear Parameter Varying) and a gain scheduling PID..Special attention has been paid to the simplification as far as possible of the controller tuning process. Thus, the calibration parameters are only dependent upon some physical parameters and performance requirements of the closed-loop control: bandwidth, maximum overshoot. Performance robustness has been assessed in simulation. The whole modeling, controller design and validation, as well as robustness analysis have been performed using Matlab/Simulink®. Finally, the strategy has been validated on a vehicle using rapid prototyping tools.

Model based mass soot observer of diesel particle filter

Abstract Diesel Particulate Filters (DPF) has now been proven as an efficient solution in order to reduce Diesel PM emissions. Concerned by environment, Renault will equip all serial production Diesel vehicles with this technology. Main issue of such devices is the mandatory periodical regeneration in order to eliminate their soot content. The particulate filter (DPF) is used to store the soot emitted by the combustion engine. When the mass of particles in the filter reaches a certain limit mass, it is regenerated thanks to a temperature rise (Over 600°C). In this paper, we develop a model that describes the impact of the amount of soot in the filter on the Diesel engine performance. This model is used to determine the optimal amount of soot on which the regeneration of the particulate filter shall start. Then we propose a physical model that describes the pressure drop of particulate filter according to the mass of accumulated soot and inlet DFP temperature and flow conditions. Thus, we improve a literature model so that it takes on account the passive regeneration of the filter. Finally, we design an extended kalman filter using the combination of the simplified model and a pressure drop measurement. All the experimental validations are made thanks to different configurations: engine dynamometer, chassis dynamometer and vehicles.

Water and Heat Conservation Modelling for a Reformate Supplied Fuel Cell System

Fuel cell systems are intended to generate electric power. When Proton Exchange Membrane fuel cells are used, they also generate water and waste heat from air and hydrogen or from a gas rich in hydrogen. This paper proposes models for the water and heat balance of a reformate supplied fuel cell. Models are presented for the fuel cell thermal balance, the cooling circuit and the water balance. The models are reduced for control purposes: for thermal management of the fuel cell, and to maintain a positive water balance.