Implementation method of a marine dual-fuel oil-gas multi-point gas injection control system

Abstract

This application discloses a realization method of a marine dual-fuel oil-gas multi-point gas injection control system, including the realization method of the calibration process, the correction calibration method of the small pulse width injection fuel volume of each cylinder electronically controlled unit pump and pure diesel-dual fuel The implementation method of the switching process. It has the following advantages: under the condition of high substitution rate, the fuel gas is mainly used for speed regulation, and the diesel speed regulation is supplemented. The main part of the fuel is used for speed regulation, which improves the stability of the engine speed; The replacement rate of the engine increases the life of the engine, and the improvement of the consistency optimizes the combustion state, thereby improving the emission index.

Description

technical field [0001] The invention relates to a realization method of a marine dual-fuel oil-gas multi-point gas injection control system, which belongs to the technical field of engine control. Background technique [0002] At present, the technical scheme of marine dual-fuel engines on the market adopts a diesel-based speed regulation strategy, and gas does not participate in speed regulation. This article is referred to as the oil-top gas solution. When the engine is in pure diesel state, the strategy uses PID to adjust the oil quantity to control the engine speed. When entering the dual-fuel state, the gas valve is gradually opened, and the gas injection amount gradually increases from small to large. At this time, because the fuel supply is greater than the engine load, resulting in As the engine speed rises, the diesel PID control strategy is to stabilize the engine speed, gradually reduce the fuel injection amount, and finally adjust the engine speed to the set spee...

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Problems solved by technology

[0003] The above scheme has the following problems. When the diesel substitution rate is small, diesel oil accounts for a large proportion of the total fuel, and the speed regulation plays a major role, which can well control the engine speed. The proportion is basically the same, and it has a similar effect on engine speed regulation, and the speed can still run normally. When the diesel substitution rate continues to increase to more than 80%, since most of the diesel is replaced by gas, the gas plays a major role in engine speed regulation. , the amount of diesel injection is relatively low, which will cause the following problems:

[0004] 1. Due to the high replacement rate, a small amount of diesel oil is still used to adjust the engine load change. When the engine load changes greatly, the adjustment effect is weakened, and the engine speed is unstable. The real machine test shows that the replacement rate of this scheme is difficult to exceed 90%.

[0005] 2. The amount of diesel fuel injection is too small, and the consistency of the fuel injection amount varies greatly when the fuel injection amount is small. The difference in the consistency of the fuel injection amount at idling speed is about 15%-25%. The difference leads to uneven ignition energy, resulting in inconsistent cylinder pressure of each cylinder, and the difference in cylinder pressure can reach 30%, which deteriorates the consistency of work of each cylinder, reduces engine life, and poor emission effect

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