废气涡轮增压器旁通阀开度优化研究

采用GT-Power仿真软件建立了小面径比(A/R)增压柴油机仿真模型;并通过发动机台架试验验证仿真模型计算结果的准确性和合理性。在此基础上对外特性各转速下旁通阀开度进行了标定和优化;并分析不同开度对柴油机性能的影响规律,以及高速工况下涡前压力和进气压力两者对柴油机性能的影响。结果表明匹配小涡轮时,通过优化旁通阀的开度可以使进气压力和涡前压力平衡;并提高中高速扭矩,改善经济性。高速时,涡前压力是影响柴油机性能的主要因素。

Optimization of Wastegate Opening in Exhaust Turbocharger

A simulation model of turbocharged diesel engine with a small area-radius radio(A/R) is established by GT-Power software. And accuracy and rationality of the simulation model had been proved by test results. The calibration and optimization of external characteristics is based on the model. We can analyze the rules of performance in diesel engine with different opening of wastegate and the effect of pressure before turbine and intake pressure. The results showed that when matching small turbine,through the optimization opening of wastegate, it can make balance between intake pressure and pressure before turbine at high speed, and improve the torque and fuel consume rate at middle and high speed. At high speed, the pressure before turbine is the main factor affecting the performance of diesel engine.