A lean-burn method for a dual-fuel engine

Abstract

The present invention relates to the technical field of internal combustion engines, in particular to a method for lean combustion of a dual-fuel engine. In the method, an injection system is installed in the intake port of a direct injection gasoline engine. When the direct injection gasoline engine is running, a single Inject gasoline, inject polyoxymethylene dimethyl ether one or more times in the combustion chamber, and ignite the extremely lean gasoline mixture through polyoxymethylene dimethyl ether, widen the lean combustion limit of the engine, achieve stable ignition and combustion, and reduce combustion Indoor NOx emission, and increase the engine compression ratio, to achieve the purpose of improving the thermal efficiency of the engine.

Description

technical field [0001] The invention relates to the technical field of internal combustion engines, in particular to a lean combustion method for a dual-fuel engine. Background technique [0002] The automobile industry is an important part of my country's economic structure. The number of vehicles on the market is increasing every year, and most passenger cars use gasoline engines as their power source. Compared with diesel engines, port injection gasoline engines have a lower compression ratio. At the same time, there are The larger pumping loss results in lower efficiency of the gasoline engine. [0003] After research and experiments, lean combustion is an important way to reduce fuel consumption of gasoline engines. As the air-fuel ratio becomes smaller, both fuel consumption and NOx emissions are significantly reduced; when the air-fuel ratio becomes smaller to a certain extent, both ignition and combustion become unstable, and fuel consumption start to rise. [0004]...

AI Technical Summary

Problems solved by technology

The lean burn method of non-direct injection gasoline engine can achieve a small lean burn limit, the structural design is too complicated, and the fuel saving ability is limited

However, the in-cylinder direct injection lean-burn method can expand the lean-burn limit to over 40 air-fuel ratio, saving 20%-30% of fuel compared to traditional port injection gasoline engines, but it is necessary to ensure that the concentration of the mixture around the spark plug during ignition is appropriate and organized. Stratified gas mixture and combustion process are very difficult, and it is difficult to ensure normal ignition and combustion under all working conditions

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