Analysis Of Combustion Noise And Control Strategy Of 6200 Marine Diesel Engine

One of the main sources of ship noise problems is the diesel engine as its main power or backup power.Therefore,when the ship uses diesel engines,the noise level is an important consideration.In recent years,with the increase in ship power demand,the design power density of diesel engines has also increased year by year,and the noise sound pressure level of diesel engines has also increased year by year.Combustion noise is one of the main components of diesel engine noise.How to optimize the combustion noise of diesel engines has become the focus of industry research.In this paper,for a 6200 direct injection diesel engine(for ships),the combustion status of the 6200 diesel engine is modeled and analyzed by AVL FIRE software.The transient combustion conditions of the diesel engine are mainly studied,and the pressure rise rate peak index that characterizes the combustion noise is optimized.,The main work is as follows:(1)The combustion noise generation mechanism and control strategy of marine direct-injection diesel engines are studied.The main mechanism of combustion noise generation is caused by changes in cylinder pressure during different periods of the combustion phase.In different phases,the rapid combustion period has a rapid pressure rise rate.Increase is the key element that affects combustion noise;therefore,the control methods for combustion noise are all based on optimizing combustion and pressure rise rate.The optimization method for combustion in this article is to adopt different injection strategies;(2)The noise test of the 6200 marine diesel engine was carried out in the semi-anechoic laboratory,and the response relationship between the combustion process and the combustion noise was analyzed,and it was found that the pre-injection combustion would have a significant impact on the combustion noise.(3)Use AVL FIRE software to model and analyze the transient combustion in the cylinder of the 6200 diesel engine,design calculation schemes for different diesel engine in-cylinder fuel injection strategies,and optimize the pressure rise rate peak index from it The smallest in-cylinder fuel injection strategy for diesel engines.The analysis of the transient operating conditions of the combustion noise of the 6200 diesel engine plays an important role in optimizing the combustion process of the diesel engine and reducing the combustion noise.At the same time,it also clarifies the noise reduction path of the marine diesel engine.