Application of Methanol with an Ignition Promotor in a Medium Speed CI engine

This work presents the early findings of methanol application in a direct injected compression ignited combustion engine. A two cylindered and four stroke BUKH DV24 engine with a geometric compression ratio of 18 is used. The engine operates at 1200 rpm, and one cylinder is fired with diesel to provide smooth engine rotation.

The other cylinder - the experimental cylinder – is charged with air (at a slightly positive gauge pressure) and fired with methanol blended with a fuel additive. With 5 % (m/m) fuel additive and „early” fuel injections (around 45 crank angles before the top dead center) the fuel-blend provides a reasonable partially premixed combustion process.

The combustion is, however, limited in terms of injection timing- and excess air ratio variations. Operation at later „diesel-like” injection timings requires a high compression ratio, which in this work is simulated by heating the charge air. With 5 % (m/m) fuel additive, a charge air temperature above 100 °C provides a less rapid combustion with lower efficiencies compared to the early injections.