Experimental investigation on effect of combustion chamber geometry and port fuel injection system for CNG engine

Abstract

Compressed natural gas (CNG) is the most favorite for fossil fuel substitution because of low pollutant and Carbon dioxide emission. Recently rising fuel cost, energy security and environmental pollution issues are becoming important concerns world over, so amongst the various alternatives CNG is the most practical solution. There are four methods to inject the CNG into the engine cylinder, such as gas mixer/carburetor injection, manifold injection, port injection and direct injection. In port injection CNG engines, gaseous fuel is injected by fuel injector through intake port into combustion chamber. This project work presents improvement for air-fuel mixing in the combustion chamber by the use of pressurized flow of CNG inside the cylinder with the help of CNG injector through intake port. The modification is focused on the intake fuelling system. For fuelling system the port injection of CNG gas must be used because of major limitation for other types of fuelling system from availability, installation and emission point of view. Experimentation work carried out on a Greaves made engine having cubic capacity of 600cc dedicated CNG engine and the effects of CNG injection through modification of combustion chamber geometry on the engine performance in terms of parameters like Brake torque, Brake power, BMEP, BSFC, and Exhaust gas temperature of the engine was examined.