Experiments Study On The Influence Of Combustion Mode Of Methanol On Performance Of SI Engine

In the 21st century, traditional energy crisis and global environment worsening have been vital issues that the whole world faces. In China, petroleum import dependency nearly rose to 50% and it is a great challenge for the development of energy technology. Thus, searching and confirming clean and efficient substitute for petroleum fuel according to our resources and environment state have been urgent issues, which relate to saving petroleum resources, national safety, environmental protection and is the requirement of the development of national economy and society.Based on coal resources which leads an energy advantage in our country of and mature technology of making methanol from coal, the author carried out research on the application of the methanol in gasoline engine in two aspects after an intensive analysis of the characteristic and researching status of methanol.In recent years, little research has been done on the performance of electronic control gasoline engine operating on alcohol fuel, especially on the detection and control of unregulated emissions. Thus, the economic fuel consuming characteristic and emission of electronic control gasoline engine are studied in this paper. In the test, methanol and formaldehyde in the exhaust emission were collected by the acidic saturated solution of 2,4-dinitrophenyl hydrazine (2,4-DNPH) and converted to corresponding hydrazone derivative, and then the solution was extracted with carbon disulfide (CS2) and analyzed by a gas chromatography (GC). The results showed that the engine fueled with gasoline/methanol blends has a lower equivalent brake specific fuel consumption and reduction in HC and CO emissions, but NOx emission increase at high load, compared with the baseline. For the gasoline/methanol fueling engine retrofitted a 3-way catalytic converter, HC and CO emissions of tailpipe significantly decline especially in high load while the NOx emission has hardly changed, compared with the emissions of engine-out. Formaldehyde and unburned methanol emissions of gasoline/methanol increase as the methanol addition and engine load rise, but the emissions of both of which are quite low after catalytic conversion.Relying on cooperative research project between college and enterprise, the author has studied on the performance of two gasoline engines and vehicle fueled with dissociated methanol from an on-board reformer. The design and improvement of methanol pyrolyzer were described and power performance, fuel economy, reliability and emissions benefits were measured. The results showed that when gasoline engines operating on dissociated methanol, the engine fuel economy and exhaust emissions can be greatly improved and it can meet the requirement for the test of automobile performance. It is concluded that dissociated methanol is a clean and efficient and easily industrialized substitute for gasoline.