Combustion Parametric Investigations of Methanol-Based RCCI Internal Combustion Engine and Comparison with the Conventional Dual Fuel Mode

Abstract

Reactivity-controlled compression ignition (RCCI) is an advanced combustion mode. Its uses two fuels with different physical and chemical properties to form a combustible mixture with active stratification. RCCI can flexibly control the combustion process by changing the concentration and activity of the combustible mixture. It can also reduce the emission of NOx and particulate matter in the engine without significantly reducing the thermal efficiency. Among various fuel combinations, methanol as an oxygen-containing fuel, has a high latent heat of vaporization, which is conducive to reducing combustion temperature and achieving low-temperature combustion. This experimental study explores the potential of Methanol-Diesel Reactivity Controlled Compression Ignition (RCCI) in achieving low emissions and high thermal efficiency and compares this with the conventional dual fuel mode. Low-temperature combustions such as Reactivity Controlled Compression Ignition (RCCI) have been shown to be a promising way to reduce pollutants at the exhaust, i.e. NOx and soot emissions. and increase the thermal efficiency of future engines. The methanol to diesel energy share (MDES) could be enhanced to 56% in the RCCI mode with proper setting of the injection parameters from 45% in the dual fuel mode. A higher quantity in the second diesel pulse that occurred close to TDC led to higher thermal efficiency and good combustion stability. Engines working in a dual-fuel mode need special conditions to ignite an air-fuel mixture without a spark plug in a good moment with high combustion efficiency.