Converting compression ignition engine to dual-fuel (diesel + CNG) engine and experimentally investigating its performance and emissions

Abstract

One of the suitable solutions for burning natural gas in diesel engines is the use of dual-fuel technology. In this study, the MT440C compression ignition engine has been converted to dual fuel (diesel + CNG) simultaneously combustion of diesel fuel and natural gas, with the least amount of engine changes and using the most amount of natural gas. The ignition of the engine was in the range of the governor. Experiments in stable conditions for the working modes of the engine were performed with pure diesel fuel and mixed gas diesel fuel. The effects of natural gas fuel as the main fuel and diesel fuel as the spark ignition on a 4-cylinder compression ignition engine were investigated on the performance and emissions. According to the engine speed and load, the amount of diesel-fuel injection was adjusted by making mechanical changes in the governor, while the ignition system was not used. These tests were performed at engine speeds of 1,200, 1,400, 1,600, 1,800, and 2,000 rpm, using single diesel fuel and dual fuel (diesel + CNG). These data were collected in the Engine Research Center of Tabriz Motorsazan Company, and experimental runs were repeated three times One of the goals of this research is to reduce the consumption of diesel fuel, and in the current study, compressed natural gas (CNG) is 72% and diesel is 28% of the dual fuel in idling. This study showed that the emission of some pollutants increased and some decreased in the dual-fuel mode. Therefore, more research is needed on modifying the diesel injection system as a spark plug or the CNG injection system to reduce the emission of greenhouse gases.