Combustion of a Spark-Ignition Methanol Engine during Cold Start under Cycle-by-Cycle Control

Abstract

The effects of ambient temperature, intake air preheating, additional liquefied petroleum gas (LPG) injected into the inlet port, and methanol injection timing on the cold-start first cycle firing behavior of an electronically controlled inlet port methanol injection spark-ignition (SI) engine were investigated under a single-cycle fuel injection strategy. The results showed that the ambient temperature significantly affects the start firing behavior of the engine. When the ambient temperature is below 16 °C, the methanol engine can not be started reliably without auxiliary start aids even at the large amount of methanol injected per cycle. Using a glow plug to heat the engine inlet manifold and additional LPG injected into the inlet port result in a reliable firing of the engine. The amount of methanol injected per cycle for the reliable firing during the cold start of the engine reduces obviously, and the cold-start performance improves significantly with the rise in ambient temperature. If the fuel inj...