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

该项目旨在展示使用先进的天然气双燃料轻型柴油发动机的潜力，以显着减少发动机排放的二氧化碳。这种类型的发动机同时吸入新鲜的空气和一定量的气体燃料，以产生稀薄的预混合进气。然后，该稀充量被压缩，并且在接近压缩冲程结束时，少量柴油燃料（引燃燃料）被喷射到气缸中。在延迟时间段之后，该引燃柴油燃料然后点燃并且引燃柴油燃料和气体燃料与空气的贫混合物两者燃烧。通过保持高压缩比，可以在高负载下实现与传统柴油发动机相似或更高的热效率。拟议的工作采用拉夫堡大学现有的研究发动机，该发动机将转换为使用甲烷作为气体燃料的双燃料。目前在轻型发动机中部署双燃料的障碍是这些较小发动机所需的较高发动机速度的结果，这导致燃烧事件在时间上较短。这是双燃料燃烧的问题，双燃料燃烧由于其预混合性质和相对低的火焰传播速率而通常具有比常规柴油更慢的燃烧。该提案旨在证明，通过使用热废气再循环（EGR）和多次柴油喷射，可以提高双燃料燃烧率以满足轻型柴油机的要求。目前，轻型柴油机部门每年排放35 MT CO2。如果英国所有的轻型柴油车都转换为双燃料天然气，二氧化碳排放量每年可减少7公吨。对于车队应用的初始部署，轻型双燃料车辆将减少20%的二氧化碳排放量，同时降低燃料成本;甚至安装燃料输送系统的成本也将在大约5年内收回。这些影响，一旦技术已经证明，应该是感兴趣的轻型运输车辆车队的运营商以及主要的汽车公司。

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.