Executive Summary : | Global transport continues to rely on internal combustion (IC) engines due to the high energy density of fuel, vast production, extensive and matured fuel distribution network, and mature technology of production of petroleum fuels. However pollution control agencies view two engine families with red eyes, namely SI engines and CI engines, in addition to depleting fossil fuel reserves and availability of poor quality petroleum from the reservoirs, which is leading to production of lower quality conventional fuels.
Researchers are therefore trying to reduce harmful engine-out emissions, while trying to make use of lower quality and cheaper fuels available. Presently, heavy-duty vehicles are operating with compression ignition (CI) engines using diesel because of its higher thermal efficiency compared to its spark ignition (SI) counterparts. However modern diesel fuelled CI engines are relatively more expensive, complicated and emit higher nitrogen oxides (NOx), and particulate matter (PM). On other hand, SI engines emit relatively lower emissions using gasoline, but with relatively lower thermal efficiency due to possibility of knocking for higher CR engines. However, it is possible to use the merits of CI engine and gasoline fuel to meet increasingly stringent emission norms.
Fuel demand will increase for diesel and jet fuels in near future, which will result in surplus availability of gasoline in the refineries, which can be used to power the Gasoline compression ignition (GCI) engines. GCI is a technology, which takes advantage of higher volatility and higher auto-ignition temperature of cheaper, low octane gasoline in a CI engine with high compression ratio. This will tackle soot and NOx emission issues simultaneously, which are generally emitted from diesel-fuelled CI engines. However, cold start, higher CO and HC emissions, combustion stability at part loads, and higher combustion noise at medium-full loads remains as challenging problems associated with GCI technology. In this project, we will try to explore the advantages of low octane fuel using GCI technology in the context of India. A prototype of GCI engine will be developed after suitable spray studies. ECU calibration for GCI combustion will be undertaken in this project. A detailed study will be done to improve the combustion, performance & emissions characteristics of gasoline-fuelled compression ignition engine. |