Effect of Natural Gas Composition on the Performance of a CNG Engine

摘要

Compressed Natural Gas (CNG) is considered an alternative vehicle fuel because of its economical and environmental advantages. However, the varying composition of natural gases produced in different parts of the world is known to affect the performance and emissions of CNG engines. Thus, the objective of this paper is to corroborate the effect of fuel composition on the combustion and emissions of CNG engines. This paper presents the overall combustion characteristics obtained from running a 2.5?L, 4-cylinder CNG engine, retrofitted from an IDI diesel engine and equipped with an engine dynamometer. Engine power, BSFC, combustion pressure, and emissions were measured under steady state operation conditions at full and partial loads. Experimental results showed that the CNG composition had a significant influence on engine performance, fuel economy, and burning rate. A correlation has been proposed to help gain insight into the relationship between the Wobbe Index (WI) and engine power, and it provides a practical method for estimating the engine power when the composition of natural gases changes.