可变几何排气管增压系统高原适应性计算研究

Computation Research on Plateau Adaptability of Variable Geometry Exhaust Manifold Turbocharging System

建立并校核了D6114柴油机的原机性能仿真模型,并通过压气机图谱的高原特性修正和增加调节阀将其改建成可变几何排气管增压系统模型,进行了固定海拔、固定转速和变海拔性能计算。研究结果表明:可变几何排气管增压系统通过开启调节阀可以改善中高转速的动力和经济性能,而对低速工况作用较小;除海拔2 000m以外,其他海拔下发动机转速上升到1 400r/min时需要开启调节阀;可变几何排气管增压系统可以使最大扭矩和最低燃油消耗率所对应的转速不随海拔高度的变化而变化。

A performance simulation model of Model D6114diesel engine was built up and calibrated to achieve the variable geometry exhaust manifold turbocharging system model based on the plateau characteristic correction of compressor map and adding a regulating valve.Performance calculations in constant speed,fixed altitude and variable altitude conditions were carried on.Results show that the regulating valve opening in variable geometry manifold turbocharging system can improve engine power and economy in medium and high speed conditions,but the effect in low-speed condition is slight.For the turbocharging system it is needed to open the regulating valve when engine speed rising up to 1400r/min at all altitudes except 2000m.The maximum torque speed and minimum specific fuel consumption speed can be keep constant independent of altitude,by using the variable geometry exhaust manifold turbocharging system.