" Soutenance de thèse de Pietro Matteo PINAZZI. | Université d'Orléans

Université d'Orléans

Soutenance de thèse de Pietro Matteo PINAZZI.

18/01/2018 - 14:00 - 18/01/2018 - 18:00

URL: http://www.univ-orleans.fr/actus/soutenances

Nom du contact: Etudes Doctorales

Courriel du contact: etudes.doctorales@univ-orleans.fr

Lieu: Amphithéâtre Turing - Polytech’Orléans – site Galilée - 14 rue d’Issoudun - campus UNIVERSITÉ

Titre : Potential of ozone to enable the low load operation of a gasoline compression ignition engine.

Discipline : Energétique

ECOLE DOCTORALE EMSTU

Résumé :

Gasoline Compression Ignition (GCI) engine, relying on Gasoline Partially Premixed Combustion (GPPC) has potential for efficient and clean operations. GCI engine showed to be effective at high load, however, the high octane number of gasoline dramatically limits low load operations. The present work investigates the potential of using ozone, a strong oxidizing agent, to improve gasoline reactivity and enabling low load GCI operation. Ozone can be produced in-situ and on- demand by equipping the engine with an ozone generator, without a dramatic impact on the engine cost and the engine control complexity. Experiments in a single cylinder engine showed that ozone promotes gasoline HCCI combustion, making possible to extend the lean limit and reducing the minimum temperature needed for autoignition. Optical diagnostics showed that these properties are related to an increased radical proliferation related to ozone-induced low temperature reactions. In parallel, GCI combustion process was investigated under low load conditions. Without ozone, the intake temperature should be considerable increased to enable autoignition of lean gasoline-air mixtures. Moreover, results indicated that the NO contained into residual burnt gases can strongly promote GCI low load combustion. Finally, the effect of ozone was investigated under GCI direct-injection conditions, demonstrating that low load GCI operation with low NOx and Soot emission can be achieved by seeding the intake of the engine with ozone without needing of increasing the intake charge temperature or boosting the intake pressure.