Study On Performance And Experiment Of A Type Of Diesel Engine

The expansion needs have appeared in some shipping markets for offshore and inlandbasin at the present stage, for Marine engine mainly concentrated in the high-speed andhigh-power diesel engine of300kW~2000kW. Such diesel engines mainly rely on imports inChina now. According to the National needs for dynamic skills upgrading, the design aims toimprove and innovate the technology of234series diesel engine, which is to achieveindependent research and development of a certain type of diesel engine. Then the gaps ofequipment in our country will be filled.The design and development process of the diesel engine is relatively complex. Takingthe internal combustion engine simulation software GT-Power as a platform, such designhas completed the numerical simulation research for this design in order to preferablyevaluate the overall performance of such diesel engine, which will laid the theoreticalfoundation for the optimization of the diesel engine later. Main subject of the content asfollows:(1) Establish physical and mathematical models of various subsystems of diesel engine:the computational model of working process in cylinder using zero-dimensional mode;establish the model of gas flow in the inlet and exhaust pipe using one-dimensional unsteadyflow model and discrete partial differential equations with finite volume method; andestablish the calculation model of exhaust gas turbocharger, according to equilibriumconditions of exhaust gas turbocharger.(2) Establish steady-state calculation model of such diesel engine by using simulationsoftware GT-Power, make the performance test, compare the simulation result with theexperimental data and they are in good agreement, which verifies the correctness of themodel.(3) Change the distribution timing, injection advance angle and compression ratio on thebasis of simulation model of the original machine in order to make the engine economy intofull play, go on the simulation calculation for the calibration condition. Then select the bestscheme by analysising calculation results.(4) Redesign the constant pressure and MPC exhaust pipe on the basis of the pulse exhaust system of the original engine, make the simulation calculation for such the dieselengine in accordance with the standard characteristic in different load conditions usingGT-Power, and obtain the optimal design scheme by comprehensively analysising thecalculation results. Then proceed high load3-d numerical simulation for the pipes by usingthe FLUENT software, master airway gas flow in detail, which improves design reference forthe design improvement of the exhaust system.