Multi-section jetting method for igniting natural gas engine through diesel micro jetting

Abstract

The invention discloses a multi-section jetting method for igniting a natural gas engine through diesel micro jetting. When natural gas is ignited through diesel micro jetting, diesel is jetted in twostages in one working cycle of a piston on the condition that the total diesel jetting amount is unchanged; the timing of the first stage of jetting is prior to that of the second stage of jetting; and besides, diesel jetting in the first stage is performed for N times, and N is greater than or equal to 1. By adopting the method, the thermal load of a diesel jetting nozzle is lowered; and reliability of a diesel jetting device is improved, and the service life of the diesel jetting device is prolonged.

Description

technical field [0001] The invention belongs to the technical field of automobile engines, and in particular relates to a multi-stage injection method for micro-injection of diesel to ignite a natural gas engine, which is suitable for reducing the heat load of a fuel injector. Background technique [0002] In recent years, diesel micro-injection ignition is the development trend of pilot-ignition natural gas engines. On the one hand, since the amount of pilot fuel in diesel-ignition natural gas engines is an important parameter that determines the combustion and emissions in the engine cylinder, a large amount of pilot fuel will cause The combustion in the cylinder is too intense, which has a negative impact on the structural strength and emissions of the engine. In order to solve this problem, it is necessary to greatly reduce the amount of pilot fuel or even use micro-injection ignition methods to reduce the ignition intensity of the gas mixture in the cylinder and slow dow...

AI Technical Summary

Problems solved by technology

[0003] Chinese Patent: Application Publication No. CN109209656A, Application Publication Date January 15, 2019 The invention discloses a combustion organization method of a natural gas engine with multiple injections, low-pressure gas supply in the pre-combustion chamber and micro-injection of diesel fuel. In this method, a single The gas supply valve injects natural gas into the pre-combustion chamber during the intake stroke, and the high-pressure natural gas injection valve directly injects natural gas into the cylinder multiple times to form mixed gas stratification with different concentration gradients in the cylinder under different engine loads. The pre-combustion chamber is located in the cylinder In the middle of the cover, the fuel injector injects a small amount of diesel into the pre-combustion chamber near the compression top dead center. Reliable ignition and high-efficiency, low-emission combustion of natural gas engines. Although this method achieves mixture stratification with different concentration gradients in the cylinder through multiple injections of natural gas, the cooling effect of micro-injection diesel on the injectors in this method Poor, which makes the thermal load of the injector higher, reducing the reliability and service life of the injector

Therefore, there is a problem of high thermal load on the injector

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