Experimental Investigation on Performance and Emissions Characteristic of Dedicated CNG Engine

An emission from public transportation is a major concern today. The immediate need is to reduce the emissions and improve the efficiency and performance of these vehicles. This is not possible with the convention engines as they are designed for low compression ratio (CR) and for specific fuels only. To achieve this with less cost, the only option available is dedicated CNG engine in which higher CR can be used as compared to conventional engines. An experimental study was conducted on this engine by changing CR to 12:1 by modifying base Gasoline engine with CR 9:1 by changing the piston shape and clearance volume. Comparative study of performance i.e., Brake power (BP), Brake specific fuel consumptions (BSFC), Torque and Brake thermal efficiency (BTE) and emissions has been done with dedicated CNG engine and base engine with LPG, CNG and gasoline fuels. From this study, it is observed that dedicated CNG engine is giving 20.5% higher BTE, 19.3% more BP, 17% better BSFC,11.7%low exhaust gas temperature,68.8%,35.7% and 176.7%less HC+NOx, CO and CO2emissions respectively as compared to baseline CNG engine. It is also observed that the power recovered is slightly in this engine.