Search Results

Compressed Natural Gas (CNG) is now looked upon as a leading renewable fuel for vehicles in INDIA due to mounting foreign exchange expenditure to import crude petroleum. Impending stringent emissions regulations for diesel engines, specifically exhaust particulate emissions have caused engine manufactures to once again examine the potential of alternative fuels. Much interest has centred on CNG due to its potential for low particulate and hydrocarbon based emissions and adulteration hostile nature. Significant amount of research and development work is being undertaken in INDIA to investigate various aspects of CNG utilization in different types of engines. This paper discusses the methodology for conversion of a diesel engine to dedicated CNG engine and to make the engine to meet EURO-V norms. The primary modifications are made on the piston, cylinder head, intake manifold, throttle body adaptation and exhaust system.

The objective of the diesel engine development program is not only providing the maximum thermal efficiency but also to meet future stringent emission targets. The focus should be on controlling and reducing the unburned emissions, especially blow-by emission apart from controlling burnt emissions. In some extreme cases blow-by may contribute up to 50% of the total oil consumption of the engine. These blow-by emissions are the responsible phenomena for the engine operation, the economy and ecology expressed through the oil consumption and oil change interval rates. Engine breathing system is the most complex circuit within the engine, the air entrapment into space above oil in engine system is pushing more oil from sump. This should be avoided. In effect of controlling these factors the engine breathing system should be properly designed and maintained.