复杂换热条件下离心压气机内部传热特性研究  

Heat Transfer Characteristics of a Centrifugal Compressor Under Complex Heat Transfer Conditions

作　　者：赵琛杰 王鹏霄 祁明旭[1] 胡良军 杨长茂[1] ZHAO Chen-Jie;WANG Peng-Xiao;QI Ming-Xu;HU Liang-Jun;YANG Chang-Mao(School of Mechanical Engineeringf Beijing Institute of Technology,Beijing 100081,China;Ford Motor Company,Dearborn,MI 48124,USA)

机构地区：[1]北京理工大学机械与车辆学院,北京100081 [2]Ford Motor Company,Dearborn,MI 48124,USA

出　　处：《工程热物理学报》2021年第7期1719-1725,共7页Journal of Engineering Thermophysics

摘　　要：油雾在离心压气机扩压器壁面上的碳化结焦导致压气机效率急剧下降,离心压气机冷却是减少结焦的有效方法,研究压气机内温度分布及传热特性是压气机冷却结构设计的重要依据。本文基于流-热耦合数值分析方法和实验手段,对强换热条件下离心压气机内温度分布进行了分析和验证,研究了不同工况条件下压气机冷、热端传热特征以及扩压器表面温度分布特性。结果表明,压气机内压缩空气为主要热源,与之接触的壳体具有较高温度,扩压器表面最高温度出现在入口处轮毂侧。流体内近壁面温度梯度较大。扩压盘表面传热系数沿径向显著降低,说明边界层的发展阻碍流固间传热,采取冷却措施将有效降低壳体温度,抑制结焦现象。Deposit formation within turbocharger centrifugal compressor housing is a main issue that leads to significant compressor efficiency degradation.Housing temperature decrease by compressor cooling is an effective method to reduce this coking effect.The study of temperature distribution and heat transfer characteristics in compressor is of guiding significance for compressor cooling design.In current study,the temperature distribution in the centrifugal compressor under complex heat transfer conditions was investigated with both flow-thermal coupling numerical and experimental methods.The heat transfer characteristics of the cold and hot ends of the compressor and the surface temperature distribution of the diffuser under diverse working conditions were also carried out.Results show that the compressed air is the main heat source in the compressor,which leads to the high temperature level at the contacting surface of the housing.The highest temperature of the diffuser surface appears at the hub side of the inlet area and significant temperature gradient can be observed near the diffuser wall.The heat transfer coefficient on the diffuser wall decreases significantly along the radial direction,which indicates that the development of the boundary layer hinders the heat transfer between the fluid and the solid.Therefore,technical approach by using compressor housing cooling measures can effectively decrease the diffuser wall temperature and mitigate coking effect.

关 键 词：离心压气机 扩压器 流热耦合 气溶胶 压气机冷却 

分 类 号：TK123[动力工程及工程热物理—工程热物理]