ALTERNATIVE FUELS FOR HCCI ENGINE TECHOLOGY AND RECENT DEVELOPMENTS

Homogeneous charge compression ignition (HCCI) combustion is an alternative to current engine combustion systems and is used as a method to reduce emissions. It has the potential nearly to eliminate engine-out NOx emissions while producing diesel-like engine efficiencies, when a pre mixture of gas-phase fuel and air is burned spontaneously and entirely by an auto ignition process.Due to the stringent emission norms, the research in the field of internal combustion engines in general and diesel engines in particular gathered huge importance and also increasing demand on fuel consumption. So high demands are placed on large gas engines in the areas of performance, fuel consumption and emissions. Homogeneous Charge Compression Ignition (HCCI) engines promise high thermal efficiency combined with low levels of nitric oxide and particulate matter emissions. However, due to the absence of an immediate means of triggering ignition, stable operation over a wide range of conditions and transient control have proven most challenging and have so far prevented commercialization by opening up new technical avenues, such as micro- hybridization and bio fuels. Most alternative fuel conversions involve reconfiguring a gasoline or diesel vehicle or engine to operate on natural gas, propane, alcohols, or on a blend of conventional and alternative fuels. Use of clean alternative fuels opens new fuel supply choices and can help consumers address concerns about fuel costs, energy security, and emissions. HCCI engines can operate on gasoline, diesel fuel, and most alternative fuels. HCCI combustion is achieved by controlling the temperature, pressure, and composition of the fuel and air mixture so that it spontaneously ignites in the engine. This control system is fundamentally more challenging than using a spark plug or fuel injector to determine ignition timing as used in SI and DI engines, respectively. The purpose of this study is to summaries the alternative fuel effect by adopting low-pressure injectors as an alternative for