27T车用柴油机热力计算及高压共轨供油系统设计1.docVIP

CENTRAL SOUTH UNIVERSITY 本科生毕业论文（设计） 题 目 2.7T车用柴油机热力计算及高 压共轨系统设计 学生姓名 指导教师 学 院 专业班级 完成时间 年 月 日 2.7T车用柴油机热力计算及高压共轨系统设计 摘 要：设计简要介绍了车用柴油机的组成，并详细进行了2.7T车用柴油机的参数及热力计算。采用四冲程，直列缸，涡轮增压中冷，直喷燃烧室，压缩比为。标准工况下，热计算和热平衡结果为有效功相当的热量占燃料总热量的4%。外特性参数结果为有效功率8,有效扭矩23N·m，。燃料有效油耗17g/kW·h。并且随着转速的提高油耗率先降低后升高，在2000rpm时有最小值15g/kW·h，每小时耗油量和机械损失压力随着转速的提高而增加。而后进行了高压共轨供油系统设计，其中喷油泵采用的是用负荷弹簧和旋转轴凸轮使柱塞运动的滑阀式喷油泵。喷油器选择4孔长型喷油嘴,出油阀选择等容式出油阀，输油泵选择活塞式输油泵，与国内外主流车型相比，在燃油经济性方面具有较大优势，排放能达到欧III标准，零部件的设计加工比较容易，整车性能较稳定。理论结果表明，所设计的供油系统能够满足设计要求 关键词：车用柴油机；高压共轨；供油系统；喷油量2.7 T automotive diesel engine thermodynamic calculation and the high pressure common rail system design Abstract:This paper introduces the composition of vehicle diesel engine briefly,and march the parameter and thermodynamic calculation of the 2.7 turbo automotive vehicle diesel engine in detail,the system use four cycle ,straight-four and turbo Charging with Inter-cooling,Straight spray combustion chamber engines,the ratio of compression is .When Standard conditions the parameter and thermodynamic calculation result is effective work considerable heat accounted for 47.2%of the total fuel heat.External characteristic parameter results are the effective power is 80.4kW,effective torque is 233N·m,effective fuel consumption rate is 179.6g/kW·h.And as the rotational speed increases fuel consumption first decreased and then increased,When Rotational speed is2000rpm,has minimum value 158.35g/kW·h,Per hour fuel consumption and mechanical losses pressure increases as the rotational speed increases,then this paper designs of high pressure common rail fuel injection system.The injection pump is Slide-valve fuel injection pump which causes the plunger movement by used Load spring and the rotation axis of the cam,when Standard conditions,Injector select 4-hole long style,Outlet valve choice constant volume type ,Oil pump choice piston type,when compa