Method for continuously smoothly adjusting load and combustion mode of homogeneous charge compression ignition (HCCI) gasoline engine

Abstract

The invention discloses a method for continuously smoothly adjusting a load and a combustion mode of a homogeneous charge compression ignition (HCCI) gasoline engine. The method comprises the following step of: regulating the rate of residual exhaust gas in a cylinder of the engine and the external exhaust gas recirculation rate to decouple the total exhaust gas rate in the cylinder of the engineand the temperature of the exhaust gas and eliminate working condition points requiring step regulation in the process of regulating the working conditions of the engine, so that a requirement of continuous adjustment of the combustion mode of the engine is met. By the method, the coordinated adjustment of the load and combustion mode of an exhaust gas dilution type homogeneous charge compressionignition gasoline engine in the equivalent air-fuel ratio can be realized in the whole load range, so that the concept of the combustion mode is eliminated in a control level, and the control processof the homogeneous charge compression ignition gasoline engine is converted into surface control of variables such as intake / exhaust valve lift and phase, oil injection pulse width, ignition time, external exhaust gas recirculation valve opening and the like.

Description

technical field [0001] The invention relates to a method for controlling combustion of an automobile engine, in particular to a method for continuously and smoothly adjusting the load and combustion mode of an HCCI gasoline engine. Background technique [0002] Gasoline engine homogeneous compression ignition combustion technology is a representative of the new generation of engine combustion concepts. It is a new combustion technology developed to meet the more stringent regulatory requirements in 5 to 20 years. However, there are still some problems in HCCI combustion technology that need to be overcome. One of them is Its limited operating range is not enough to cover the common working conditions of automotive gasoline engines. The main problem limiting the expansion of the load boundary on HCCI combustion is the knocking phenomenon caused by too fast combustion velocity. The main reason for this phenomenon is the insufficient amount of residual exhaust gas in the cylin...

AI Technical Summary

Problems solved by technology

It tries hard to complete the coordinated adjustment of combustion mode and load, but there is still a conversion process that requires step control of the control mechanism at a certain load

[0013] The step control used in the above patents will cause complex and difficult control in practical applications, and also requires a complex control strategy to compensate for the huge difference in the exhaust gas rate and exhaust gas temperature between the two combustion modes in the step control

And almost all papers show that the engine load will fluctuate in this step control, although a good compensation strategy can reduce this fluctuation and avoid abnormal combustion phenomena such as misfire and knocking, but it cannot fundamentally Eliminate it

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