Performances of electronic fuel injection engine fueled with methanol-gasoline blended fuel

In order to study the effects of methanol-gasoline blended fuels with different methanol volume fractions on the performances and exhaust emissions of multi-point EFI gasoline engine, the power performance, fuel economy and emission characteristic of the engine were analyzed through engine test, the non-regulated pollutant emissions, such as methanol and formaldehyde, were measured by using gas chromatography (GC), their emission characteristics and formation mechanisms were studied. The result shows that under the speed characteristic of full load, the power output of blended fuel engine is slightly higher at high engine speed, the brake specific fuel consumption is lower, and the effective thermal efficiency is higher compared with gasoline engine. Under the load characteristic of operation, the brake specific fuel consumption and effective thermal efficiency is almost similar to that of gasoline engine. With the increase of methanol volume fraction in the blended fuel, CO emission decreases, NO_x emission varies little, and THC emission slightly increases at high engine loads. Formaldehyde emission of blended fuel engine is evidently higher than that of gasoline engine, and increases with the increase of methanol volume fraction, but the methanol emission of blended fuel engine is lower.