高原环境重型车用柴油机热负荷性能分析

以高原修正的广安博之喷雾模型为基础,建立具有环境适应性的某特种车辆柴油机缸内燃烧与冷却系统传热耦合模型。海拔3 700m的实车试验表明:模型最大误差在4.3%以内。在不改变发动机部件的前提下,通过调整柴油机供油提前角和最大循环供油量,可改善高原运行时特种车辆柴油机的热负荷。试验结果表明:在海拔4 000m时,供油提前角提前4°CA可使涡前温度最高下降30℃,活塞表面温度最高下降15℃,且表面温度场分布稍有改善,但缸内温度峰值上升20℃;在满足任务工况功率需求的基础上,供油量调整螺钉拧入角度为255°时,热负荷参数满足发动机控制参数要求。

Thermal Load Analysis of Heavy Duty Vehicular Diesel Engine in Plateau Area

On the basis of modified Hiroyasu spray model,a coupling model of cylinder combustion with cooling system heat transfer in turbocharged diesel engine for special vehicle was established.Validated by road test data in 3700m altitude,the simulation result errors were within 4.3%.In stead of modifying engine components,adjusting injection advance angle and max.cyclic fuel delivery,was used to find the optimized condition to alleviate heat load of the engine operating in plateau area.Results show that in 4000m altitude area,at injection advance angle of 4°CA,the max.exhaust temperature before turbine drops 30℃,the max.temperature field of piston surface drops 15℃,piston surface temperature distribution gets a little improvement and peak value of cylinder combustion temperature increases 20℃.On the basis of satisfying the given condition power requirements,fuel adjusting bolt is driven in by 255 degree,the engine thermal load can meet the reliability requirement.