The thesis investigates how exhaust gas fuel reforming, also known as reformed exhaust gas recirculation (REGR), may benefit direct injection gasoline (GDI) engine efficiency and emissions. REGR is a thermochemical process that has potential for efficiently producing hydrogen-rich gas onboard a vehicle by using waste exhaust energy to promote endothermic reforming of hydrocarbon fuels. Partially fuelling a gasoline engine with hydrogen generally improves engine thermal efficiency. The experimental research begins by simulating REGR on single- and multi-cylinder GDI engines, which indicates that REGR can increase engine thermal efficiency by up to 9% and reduce NOx by up to 96%. Particulate matter (PM) measurements reveal that REGR significantly reduces PM number and mass emissions, beyond that achieved by EGR. Further experiments with a full-scale prototype exhaust gas fuel reformer integrated with the multi-cylinder GDI engine demonstrate improved fuel efficiency at a wide range of engine conditions, by 8% for conditions typical of motorway driving. The reforming process is observed to be overall endothermic when the exhaust temperature is above 650°C, and the reformed fuel enthalpy is increased by up to 21% in these experiments. The results demonstrate that REGR can simultaneously increase engine thermal efficiency, and reduce gaseous and PM emissions.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:629717 |
| Date | January 2014 |
| Creators | Fennell, Daniel Alexander |
| Publisher | University of Birmingham |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://etheses.bham.ac.uk//id/eprint/5439/ |
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