Experimental study on combustion characteristics of a fischer‐tropsch diesel/methanol reactivity controlled compression ignition mode engine

Abstract

AbstractF‐T diesel is an alternative fuel with a high cetane number (CN) for internal combustion engines. Methanol has a low CN and contains oxygen. F‐T diesel and methanol are potential fuels for the reactivity controlled compression ignition (RCCI) engines. In a single‐cylinder 186FA compression‐ignition engine with a combination of methanol inlet pipe injection and F‐T diesel in‐cylinder injection, the combustion characteristics of the F‐T diesel/methanol RCCI mode engine are investigated. The results show that as methanol premixed ratio (MPR) increases, the ignition delay (ID) is prolonged at low load conditions, the maximum in‐cylinder pressure (Pmax) and indicated thermal efficiency (ITE) a decreased. When the MPR increases from 0% to 60%, the ID is extended by 1.7°CA, the Pmax decreases by 8.1%, and the ITE decreases by 1.1%. At high load conditions, MPR rises from 0% to 60%, combustion duration (CD) is shortened by 2.4°CA, Pmax is increased by 8.3%, and the ITE is increased by 1.7%. The fuel injection advance angle (IAA) of F‐T diesel significantly influences the combustion process of the RCCI engine. As the IAA increases, the ID is shortened at high loads, and the Pmax and the ITE are increased. When the MPR is 60% and the IAA is 14°CA, the ITE of the engine is increased by 2.04%, and the equivalent indicated fuel consumption rate(be) is reduced by 5.68% compared with the engine fueled with F‐T diesel under high loads.