Matching For Regulated Turbocharging System And Transient Response Study Of Diesel Engine

With the power boosting of diesel engine,adjustable turbocharging system is used more frequently in diesel engine.The traditional matching method of turbocharging system is very sensitive to some experience value estimates,thus undermining the feasibility of these method.Moreover,the matching is a process of trial and error on different type of turbocharging system,which greatly increase the workload of matching.Concerning these drawbacks,this paper established a parametric model which is adjustable with the type of engine.To improve the applicability of the parameterized model,according to the universal characteristic experiment of cylinder pressure data,the apparent heat release rate as with the parameters of wiebe combustion model is obtained.The parameters of three wiebe model is related to the load and speed of the engine.Using parameterized model,the selection and matching of turbocharging system is done,and the paper gives a detailed standard process to match one-stage with wastegate,regulated two-stage and sequential turbocharging system.The matching of a diesel engine based on the same design point is also done.The torque range of the three kind of turbocharging system is studied aiming at the highest dynamic output,the strategy of bypass valve opening with speed and load is also studied.As to the problem of transient response lagging,the paper analyze the energy transfer process of a typical load acceptance case.A response indicator is put forward,which establishes a relationship between response performance and engine configuration and operation condition.The transient performance can be studied quantitatively with the response indicator at the initial stage of design processes.The calculated result of response indicator is eventually compared with simulation,which verifies the predictability of the response formula.Eventually,two-stage turbocharging system multi-objective comprehensive multi-parameter optimization is done using Isight.The fuel consumption optimal operating point,the comprehensive optimum operation points and transient characteristics of the best operating point is obtained.