Experimental investigation on performance and emission characteristics of dual fuel split injection of ethanol and diesel in CI engine

摘要

The increasingly strict restrictions being place on diesel engine emissions have the interest in alternative combustion concept. The dual fuel engine exhibits much better emission characteristics than a diesel engine whilst having similar efficiency. The dual fuel engine is investigated for their potential to achieve near zero nitrogen oxide (NOx) and soot-particle emissions. In both SI and diesel engines, the fuel must burn hot to ensure that the flame spreads rapidly through the combustion chamber before a new "charge" enters. In a dual fuel split injection engine, there is no need for a quickly spreading flame because combustion occurs throughout the combustion chamber. As a result, combustion temperatures can be lower, so emissions of nitrogen pollutants are negligible. The fuel is spread in low concentrations throughout the cylinder, so the soot emissions from fuel-rich regions in diesels are not present. As the method for reducing exhaust emissions from diesel engines, a homogenous charge diesel combustion technique is used where by a portion of fuel is supplied into the intake port to form homogenous pre mixture then the mixture is fed into the cylinder port before ignition of the diesel fuel, which is injected directly into the cylinder. The homogeneous pre mixture is prepared with the help of electronic fuel injection.