Research On Combustion And Emission Characteristics Of Marine Dual Fuel Engine Based On Two-zone Model

With the rise of the traditional energy price and the aggravation of the environmental pollution,the International Maritime Organization has put forward more and more strict requirements for ship's discharge.In order to alleviate the above problems,the development of clean energy to replace traditional energy has become an important development direction of the marine engine industry.Natural gas has attracted people's attention because of its rich reserves and clean combustion characteristics.At present,natural gas engines are mainly divided as single fuel gas engine and dual fuel engine.The diesel / natural gas dual fuel engine develops rapidly since it can not only solve the power reducing problem of single fuel gas engine,but also reduce the pollutant emissions.Among them,most researches about dual fuel engine have focused on the combustion of diesel and natural gas.In order to make a quick prediction of dual fuel engine performance and NO formation,a quasi-dimensional two-zone model is built in this paper.By introducing three new boundary parameters,a two-zone model is established in MATLAB/SIMULINK environment on the basis of traditional single-zone diesel engine working process model and the NO formation is simulated by the Zeldovice theory.The two-zone model is verified by experiment data and shows good ability to predict the in-cylinder pressure,temperature,engine performance and NO emission.Then the two-zone model theory is applied to a marine dual fuel engine model,in which the in-cylinder gas properties are calculated and three Vibe curves are used to simulate the heat release rate of the dual fuel engine.With the experimental data of 6170 marine dual fuel engine under rated condition,the Vibe parameters and two-zone boundary parameters are determined and the combustion and emission characteristics are studied.Finally,the method of determining the boundary parameters of the two-zone is analyzed,and the influence of the boundary parameters on the two-zone simulation model is studied.This paper considers the working characteristics difference between diesel engine and dual fuel engine,and the difference between single-zone and two-zone model.Then a single zone model and two-zone model of diesel engine as well as a two-zone model of dual fuel engine are established,with NO emission prediction model in them.And the influence of two-zone boundary parameters on simulation model is analyzed.The simulation model present in this paper provides rapid prediction of performance and emissions of dual fuel engine.