大型低速柴油机性能预测动态模型

性能预测模型及其仿真是柴油机设计、电控和故障诊断研究的重要手段。容积法模型能准确反映缸内压力的变化,但计算耗时长。它具有动态仿真的能力,一般应用于稳态仿真。通过对缸内工作过程和涡轮增压器模型的简化,结合曲柄连杆机构动力学模型,建立了以容积法为基础的涡轮增压多缸柴油机动态模型。缸内工作过程以曲轴转角为计算单位,其他部分以时间为计算单位。模型可观测瞬态过程中各主要参数的变化。以6S60MC型船用柴油主机为例,用MATLAB/SIMULINK实现仿真模型,在XEON3.0G工作站进行仿真。仿真结果显示,模型数据与台架试验数据吻合良好,仿真300 s耗时245.4 s,满足实时仿真的要求。

Dynamic Modeling for Performance Prediction of Large-Scale Low-Speed Marine Diesel Engine

Models and simulations for the performance prediction of diesel engine are of importance for its design,control and fault diagnosis.The filling and emptying model can accurately predict pressure variation in cylinders,yet it is usually used for steady state simulation due to its long calculation time.However,it is able to simulate transient state.After simplifying working process model and turbocharger model,a dynamic model,which is combined with dynamic model of crank and rocker mechanism,of multi-cylinder turbocharged diesel engine is presented,based on the filling and emptying model.The working process model is crank angle based,but others are time-based.The variation of main parameters in transient process can be observed.The 6S60MC marine diesel engine being taken as an example,the model is realized with MATLAB/SIMULINK and simulated in XEON 3.0 G work station.The results of simulation show that the data of modeling is consistent with the data in testing-bed tests.That it takes 245.4 seconds to simulate a 300s' real process satisfies the standard of real-time simulation.