Combustion method of ethanol-diesel double direct injection engine

Abstract

The invention discloses a combustion method of an ethanol-diesel double direct injection engine and relates to the field of engines. The combustion method of the ethanol-diesel double direct injection engine includes three combustion modes of premix quantity ignition combustion, diffusive combustion and diffusive combustion of a portion of a premix ignition portion. The ethanol-diesel double direct injection engine can selectively use the three combustion modes of the premix quantity ignition combustion, the diffusive combustion and the diffusive combustion of the portion of the premix ignition portion and can convert work modes among the three combustion modes according to working condition needs, and requirements of dynamic performance, economical efficiency and emission performance when uses ethanol-diesel double fuel to work, so that the combustion method of the ethanol-diesel double direct injection engine can satisfy requirements of substitution rate, power and emission according to different working conditions and achieve flexible application of ethanol in a diesel engine.

Description

technical field [0001] The invention relates to the field of engines, in particular to a combustion method for an ethanol-diesel double direct injection engine. Background technique [0002] In the current biomass energy, the most ideal alternative fuels for diesel engines are vegetable oil (or biodiesel) and fuel ethanol. Because ethanol is volatile, it is easy to form a combustible mixture, which is conducive to rapid and complete combustion; ethanol contains oxygen, and the combustion is more complete, which can inhibit the formation of soot and accelerate the oxidation of soot; ethanol has a large latent heat of vaporization, which is conducive to reducing the maximum temperature of combustion and reducing NO x emissions. [0003] At present, the main application methods of ethanol in diesel engines are blending, injection outside the cylinder, and direct injection inside the cylinder. The biggest advantage of ethanol blended combustion is that there is no need to make...

AI Technical Summary

Problems solved by technology

The biggest advantage of ethanol blended combustion is that there is no need to make any changes to the fuel supply system of the diesel engine, but it needs to face the low cetane number of ethanol, which makes it difficult to catch fire, and has a low flash point and poor safety. Poor stability and other problems

Premixing outside the cylinder, injecting ethanol in the intake pipe, the injection amount can be adjusted according to the working conditions to change the replacement rate, and the premixed charge can be burned quickly to improve the effective thermal efficiency, but it also faces fuel deposition due to poor atomization in the intake port, and valve overlap A small amount of ethanol is emitted during scavenging, detonation is likely to occur when the substitution rate increases, the cycle fluctuation of the combustion process increases, and the engine charging efficiency decreases, etc.