High Speed Dual Fuel Direct Injection Engines With Advanced EGR And Injection Strategies To Reduce The Carbon Dioxide Emissions

This project intends to demonstrate the potential of using advanced natural gas dual fuel light-duty diesel engines to significantly reduce engine out CO2. This type of engine ingests a fresh charge of air and a quantity of gaseous fuel simultaneously to produce a lean premixed charge. This lean charge is then compressed and near the end of the compression stroke a small quantity of diesel fuel (the pilot fuel) is injected into the cylinder. After a delay period, this pilot diesel fuel then ignites and both the pilot diesel fuel and the lean mixture of gaseous fuel and air combust. By retaining a high compression ratio, thermal efficiencies similar to or higher than conventional diesel engines can be realised at high loads. The proposed work employs an existing research engine at Loughborough University, and this engine will be converted to run on dual fuel using methane as the gaseous fuel. The barrier to the current deployment of dual-fuelling in light-duty engines is a result of the higher engine speeds required for these smaller engines, which result in temporally shorter combustion events. This is a concern for dual-fuel combustion, which typically has a slower combustion than conventional diesel because of its premixed nature and relatively low flame propagation rates. This proposal aims to demonstrate that, through the use of hot exhaust-gas recirculation (EGR) and multiple diesel injections, the dual-fuel combustion rate can be increased to meet the requirements of light-duty diesel engines.Currently the light duty diesel engine sector emit 35MT CO2 per year. If all light-duty diesel vehicles in the UK were converted to dual-fuel natural gas, CO2 emissions could be reduced by up to 7 MT/year. For initial deployment in fleet applications, light-duty dual-fuelled vehicles would reduce CO2 emissions by 20% while reducing fuelling costs; even the cost of installing a fuel delivery system would pay-back in approximately 5 years. These impacts, once the technology has been demonstrated, should be of interest to operators of fleets of light-duty delivery vehicles as well as to major automotive companies.

Since the Kyoto Protocol, all the major industrial sectors have reduced their CO2 emissions with the exception of the transport industry. Here the CO2 emissions have increased by some 13% (all forms of road transport) and were 18% of all UK greenhouse gases (GHG) in 2002 compared to 14% in 1990. The aim of this research proposal is to investigate the viability of using dual fuel technologies from large heavy duty engines on small high speed direct injection diesel engines to minimise transportation-related CO2 emissions. By employing natural gas duel engines, significant reductions in CO2 from heavy duty diesel engines have been achieved. The savings have been demonstrated on a rolling road to be as great as 20%. Thus, the potential environmental and economic implications of converting a vehicle fleet to the proposed technology would have a major impact. If all light-duty diesel vehicles in the UK were converted to dual-fuel natural gas, CO2 emissions could be reduced by 7 MT/year. For initial deployment in fleet applications, light-duty dual-fuelled vehicles would reduce CO2 emissions by 20% while reducing fuelling costs; even the cost of installing a fuel delivery system would pay-back in approximately 5 years. As bio-methane can be produced in the UK via landfill sites or anaerobic digestion, this technology could also have advantages in reducing our reliance upon imported fossil fuels. To maximize the national and global impact of this new combustion system, it will need to be adopted by a major automotive manufacturer. For engine manufacturing, no engine tooling or production changes would be needed as the base diesel engine is used unmodified. Post-production, a natural gas fuelling system would need to be added; however, major OEM's such as Ford have previous international experience in natural-gas flex fuelling systems for light-duty gasoline vehicles. The requirements for the proposed light-duty diesel fuelling system are no more complex than those for existing light-duty gasoline systems. As this system can be added post-product, no major changes to the production line would be needed until demand was sufficient to justify the production of dual-fuel vehicles as a distinct sub-model. This will help to further increase the acceptability of the proposed combustion system, achieving real, near term impacts in terms of economic benefits for UK companies (both vehicle producers and operators) as well as substantial near-term CO2 emission reductions. The potential impacts of having major fleet operators, such as the Royal Mail, operating light-duty dual-fuel diesel vehicles would be substantial.