An experimental research on the relations of fuel injection variables and exhaust emissions for diesel engines

Growing global economy, industrialization, population growth, urbanization and improved need for energy access cause rapid increase of global energy demand. Studies on estimation of the future of energy market argues the fact energy production from fossil fuels will still be dominant on global energy market in the next 50 years. However, energy production from fossil fuels is the main cause of air pollution and global warming. Diesel engines that generate energy by using fossil fuels are often preferred for energy production due to high thermal efficiency. There are various methods that can be applied to reduce the emission rates of air pollutants during the operation of diesel engines. These methods include; reduction of exhaust emissions by changes in engine operating parameters, reduction of exhaust emissions using exhaust gas recirculation systems, and removal of air pollutants using exhaust gas aftertreatment systems. In diesel engines it is possible to control the exhaust emissions by changing fuel injection and intake air supply strategies. In this thesis, influence of changes in injection pressures and injection timing on exhaust emissions and motor performance in the use of different fuels have been investigated. For this purpose, tests were conducted on a one cylinder, 11.4 kw diesel engines to investigate effects of different injection pressures (180, 200 and 220 bar) and different injection timings (15, 20 and 25 crank angle degree before top death center) by using diesel oil, marine diesel oil and fuel blend (95 percent marine diesel oil and 5 percent marine residual fuel) as fuel on specific fuel consumption, exhaust temperatures and carbon dioxide, carbon monoxide, oxygen, sulfur dioxide and nitrogen oxides emissions. The results of the test indicate the fact that diesel engines based air pollution can be reduced by using optimum injection strategy determined according to fuel type, engine load and environmental conditions.