A study of the combustion completion on the 2-stroke HCCI engine with n-butane/air mixture (investigation of the exhaust gas composition and the exhaust mechanism)

In this study, the exhaust gas composition was clarified by using a gas chromatography, and combustion completion was considered in 2-stroke HCCI engine. In exhaust gas composition, n-Butane was high concentration as opposed to calculation results and intermediate products (CO, C₂H ₄, C_aH₆, CH₄, C₂H ₆) also exhausted. Increasing maximum in-cylinder gas temperature until 1 600 K, combustion efficiency became higher and HC emissions became lower, but over 1 600 K, combustion efficiency kept constant 82±3% and HC emissions became higher again. In actual engine, it was considered that mixture near cylinder wall couldn't be ignited because of heat loss to wall. This region was almost 0.83-1.01 mm from wall by calculated from exhaust gas composition and concentration by 2 models. And the ratio of exhaust n-butane from heat loss to wall in exhaust n-butane is about 79%, from crevice is about 1%, from leak is about 20%.