Simulation And Experimental Study On The Intake And Exhaust Performance Of Large Marine Diesel Engine

Large Marine diesel engine with its superior dynamic and economic performance,widely used in the field of Marine power.The research object of this paper is type 6210 Marine diesel engine,which was designed and developed in the 1990s.Due to the technical limitations,the fuel consumption was high and the economy was poor.Therefore,the original products need to be upgraded and improved to reduce fuel consumption.This paper takes type 6210 diesel engine as the research object,the intake and exhaust performance is simulated and analyzed,established the optimization improvement scheme,The main research content is as follows:(1)According to the basic theory of diesel engine working process of the numerical calculation,illustrates the basic hypothesis of diesel engine working process calculation,and use the AVL BOOST software to create a simplified physical model of the 6210 diesel engine.(2)Through the contrastive analysis of the simulated data and test data,modify the model parameters,and the model was used to analyze the engine’s intake system,exhaust system and gas distribution.Diesel engine air intake system design is reasonable,the exhaust system exists interference,adjacent cylinder valve timing at low load inlet valve closing exists negative flow phenomenon and exhaust late mild exhaust flow backward.(3)According to the analysis of the performance,respectively with gas phase and the exhaust system design and simulation analysis,determine the optimal distribution of timing plan is:the exhaust opening Angle is 105°(CA),intake closed Angle is 590°(CA);The optimal exhaust system scheme is:the diameter and shrinkage of the exhaust pipe of the three pulse exhaust system of diesel engines are 85mm and 0.8 respectively.And the simulation analysis of the optimal scheme is carried out,the results show that the fuel economy of diesel engine is improved,the mechanical load is reduced,have achieved the effect of performance optimization.(4)The performance test of the final optimization scheme is verified,the bench test results show that:6210 in diesel engine propulsion characteristic operation,diesel fuel efficiency has decreased in condition partial and full load,compared with before the improvement,economy of diesel engine was improved,the mechanical load is effectively optimized,the experimental results are consistent with the simulation results,and the performance optimization is achieved.