Research On The Selection And Optimal Design For Low NO_X And Emission Reduction From Marine Diesel Engine

According to the implementation requirements of MARPOL convention annex VI,vessels constructed on or after January 1,2016,navigating in ECA(Emissions Control Area),nitrogen oxides(NO_X)emissions should meet the Tier?emission standards.Selective catalytic reduction(SCR)technology and the technology of exhaust gas recirculation(EGR)are the mainstream technologies of reducing NOX emission of Marine diesel engine,to meet IMO Tier?standard requirements.At present these technologies have been relatively mature,and have complete equipment and suppliers.However,it is necessary to select suitable and economical low nitrogen emission control system according to the design features and space requirements of new shipbuilding,but there is no mature application experience at present.In the context,the 64,000 tons of new energy-saving and environment-friendly bulk carrier has launched development in 2016.Based on the development of the ship type, optimize the layout,piping and performance of main engine,generator discharge system and supporting equipment to meet the requirements of Tier III,perfect green bulk cargo ship type storage,wait for the right time to market.In this paper,new technologies are selected,new technologies are optimized in layout design,and new process methods of applied key design are adopted to form a technical reserve.It provides technical support to meet the requirements and implementation plans of new green ships,and provides some technical references for the feasibility,applicability and economy study of the low-nitrogen emission technology plan in the future practical application of more new shipbuilding.In this paper,on the premise of meeting the specification,many technical points of the engineering technical solutions of EGR and SCR are discussed,including pipe design for system function,water treatment system,layout design,etc.This paper further conducted qualitative and quantitative evaluation of the two schemes.Qualitative evaluation includes policy factor evaluation,urgent evaluation and risk evaluation.The CAPEX and OPEX models are applied to analyze the cost and main economic factors.Based on the current economic environment,a better economic plan is determined.In addition,it is implemented in the actual ship project,and the relevant parameters collected can meet the emission reduction re quirements,which verifies the feasibility of the EGR emission reduction control scheme in this paper.Based on the combustion principle of diesel engine and the principle of low-nitrogen emission reduction,this paper puts forward some measures for further optimization of emission reduction,and analyzes the influence of such factors as P max(Max.explosion Pressure),Tscav.(Scavenge air Temperature),Pback(Exhaust Gas Back Pressure),etc.,to provide theoretical references for future generations.