两级可调增压系统涡轮级间性能耦合机制  

Coupling Mechanism Between Turbine Stages in a Two-Stage Turbocharging System

作　　者：刘莹 卢炤凯 杨名洋 潘镭 邓康耀[2] 丁占铭 Liu Ying;Lu Zhaokai;Yang Mingyang;Pan Lei;Deng Kangyao;Ding Zhanming(Kangyue Technology Company Limited(Shandong),Shouguang 262711,China;Key Laboratory for Power Machinery and Engineering of Ministry of Education,Shanghai Jiao Tong University,Shanghai 200240,China;National Key Laboratory of Diesel Engine Turbocharging Technology,China North Engine Research Institute,Tianjin 300400,China)

机构地区：[1]康跃科技(山东)有限公司,山东寿光262711 [2]上海交通大学动力机械与工程教育部重点实验室,上海200240 [3]中国北方发动机研究所柴油机高增压技术国防重点实验室,天津300400

出　　处：《内燃机学报》2024年第6期534-540,共7页Transactions of CSICE

基　　金：国家自然科学基金资助项目(52076130).

摘　　要：采用试验和三维计算流体动力学(CFD)数值仿真方法,研究了某重型柴油机两级可调增压系统中两级涡轮性能耦合作用规律与流动机理.两级可调增压系统中的低压级涡轮性能在涡轮级间耦合作用具有高敏感性.旁通阀关闭时,低压级涡轮性能在高负荷工况(膨胀比为2.40)时较该级涡轮独立运行工况提升约2.8%;旁通阀开启后,低压级涡轮气动效率急剧恶化,在小膨胀比工况时最高降幅达7.5%.进一步开展阀门状态导致低压级涡轮性能异化的机制分析,结果表明:旁通阀关闭时,高压级涡轮出口旋流效应在低压级涡轮进口产生的流场分布抑制了叶轮叶尖泄漏流损失;但旁通阀开启后,旁通分支气流对该旋流的推挤和掺混作用导致低压级涡轮进口产生反向的强二次涡结构,蜗壳内部流动损失显著增加.The performance coupling mechanism between turbine stages in a two-stage turbocharging system for a heavy duty diesel engine were studied by means of bench experiments and 3D-computational fluid dynamics(CFD)calculation.The performance of low-pressure turbine in two-stage turbocharging system is sensitive to the coupling effect.When the bypass valve is closed,the efficiency of low-pressure turbine is increased by 2.8%at high load conditions(PR=2.40).When the bypass valve is opened,the performance of low-pressure turbine deteriorates drastically and the efficiency is reduced up to 7.5%.Further flow field analysis was carried out on the mechanism of the performance deterioration of the low-pressure turbine caused by the valve state.The results show that,when the bypass valve is closed,the tip leakage flow loss is suppressed due to the influence of swirling flow at the highpressure turbine exit on the inlet of low-pressure turbine.On the other hand,when the bypass valve is opened,the flow from the bypass branch interacts strongly with the swirling flow,leading to a higher flow loss in the volute.

关 键 词：重型柴油机 两级可调增压 涡轮 性能耦合 

分 类 号：TK413.5[动力工程及工程热物理—动力机械及工程]