Spray Strategy Optimization Of Ships Dual Fuel Diesel Engine

LNG is a low-emission and relatively cost-effective ship fuel.Dual fuel diesel engine can effectively improve the engine's economy and emissions performance.The mathematical model which can reflect the transient performance of the dual fuel diesel engine has great significance to the control and performance optimization of the power plant.Dual fuel diesel fuel consists of methane and diesel.Methane and air fill into the cylinder compression.Forming homogeneous gas mixture,in close to the top stop point before injecting diesel.After a period of time,high temperature homogeneous gas lit it.Burning diesel(gas)ignites homogeneous mixed gas.The combustion process of the dual fuel diesel engine is combined by the flame diffusion process of the combustion of diesel fuel and the flame propagation process of the homogeneous mixture in the cylinder.In this paper,the combustion of diesel fuel has been used to Wiebe function which achieve better results to describe the combustion of homogeneous,mixture using fractal theory to calculate the turbulent combustion rate.In this paper,6S80ME-C9-GI dual fuel diesel engine of MAN B&W is the simulation object.The boundaries of the established simulation model are:double fuel diesel engine cylinders,shafts,propellers and hulls.The single cylinder output torque is obtained by simulating the single cylinder of the dual fuel diesel engine,and the output torque of the whole rotation is obtained by time delay and superposition.Output torque and propeller load torque acting on the shaft,the impact on the speed.The influence of natural gas concentration on combustion and output torque under different load was studied by simulating the diesel engine mode and natural gas mode with certain speed and different load.The effect of diesel fuel and diesel fuel consumption on fuel flow and fuel consumption is studied by using a cylinder deactivation for dual fuel diesel engines under medium and low loads.