Optimization of Gasoline to CNG Engine Conversion using Computer aided Engine Simulation
Among all the alternative fuels available in the market, CNG has so far proved to be the most promising. However, most of its use is limited to retrofitted engines, which has lead to improper utilization of CNG as a spark ignition fuel. This study focuses on efficient utilization of the high calorific value and other desirable properties of CNG by making slight design and operational changes. Performance of engine is studied using a computer aided engine simulation model that evaluates the performance of engine in a virtual working environment. Effect of various parameters on the engine operation is also studied and the valuable data collected in the process is used to alter the operational and design parameters of the engine. In this way engine is tuned for optimum utilization of CNG and its performance is enhanced as compared to the conventional CNG conversion kits.
Effect of Natural Gas Composition on the Performance of a CNG Engine
Effect of Natural Gas Composition on the Performance of a CNG Engine — 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, 4cylinder 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. Oil & Gas Science and Technology – Rev. IFP, Vol. 64 (2009), No. 2, pp. 199-206 Copyright © 2008, Institut français du pétrole DOI: 10.2516/ogst:2008044 Oil & Gas Science and Technology – Rev. IFP, Vol. 64 (2009), No. 2
An experimental investigation of CNG as an alternative fuel for a retrofitted gasoline vehicle
Abstract This paper presents test results obtained from running a 1.5 L, 4-cylinder Proton Magma retrofitted spark ignition car engine with dynamometer. Performance, fuel consumption and exhaust emissions measurements were recorded under steady state operating conditions for gasoline and compressed natural gas (CNG). The engine was converted to computer integrated bi-fueling system from a gasoline engine and was operated separately either with gasoline or CNG using an electronically controlled solenoid actuated valve system. A PC based data acquisition and control system was used for controlling all the operation. A comparative analysis of the performance and emissions has been made for gasoline and CNG. Based on the experimental results, it is transparent that CNG shows low brake mean effective pressure (BMEP), brake specific fuel consumptions (BSFC), higher efficiency and lower emissions of CO, CO 2 , HC but more NO x compared to gasoline.