超临界环形炉膛锅炉低质量流速内螺纹管传热特性  

Experimental investigation on heat transfer characteristics of low mass-flux rifled tube for supercritical pressure boiler with annular furnace

作　　者：沈植[1] 姜勇[1] 王少飞[1] 谢贝贝[1] 沈艳荣[1] 杨冬[1] 

机构地区：[1]西安交通大学动力工程多相流国家重点实验室,陕西西安710049

出　　处：《热力发电》2015年第2期52-57,共6页Thermal Power Generation

基　　金：中国科学院战略性先导科技专项项目(XDA07030100)

摘　　要：在压力p=24-32 MPa、质量流速G=420-800kg/（m^2·s）、外壁热流密度q=150-360kW/m^2的参数范围内,对低质量流速下水在超临界循环流化床（CFB）环形炉膛锅炉水冷壁中内螺纹管内的传热特性进行了实验研究,得到了不同运行工况下内螺纹管的壁温分布规律,分析了外壁热负荷、质量流速和压力对内螺纹管传热特性的影响,并给出了可用于工程实践的实验关联式。结果表明：超临界压力下,内螺纹管壁温随流体焓值的增加单调增加,在拟临界点附近发生了传热强化现象,壁温曲线变平缓,传热系数达到最大值;外壁热负荷的增大、质量流速的减小以及压力的增大都会使内螺纹管壁温升高,传热系数减小。In the range of pressure from 24 MPa to 32 MPa,mass flow rate from 420kg/（m^2·s）to 800kg/（m^2·s）,and heat flux at outer wall from 150kW/m^2 to 360kW/m^2,experiments were conducted to investigate the heat transfer characteristics of water in a vertical upward rifled tube.The temperature distribution in the tube wall was obtained.The effects of heat flux at outer wall,mass flux and pressure on heat transfer coefficient and temperature at inner wall were analyzed,and the corresponding empirical correlations were presented.The experimental results show that at subcritical pressures,the wall temperature increases monotonically with the bulk fluid enthalpy.The wall temperature rises slowly in the pseudo-critical enthalpy region,which implies that the heat transfer is enhanced.With the increase of outer wall heat flux and pressure and with the decrease of mass flux,the wall temperature rises.Meanwhile,the heat transfer coefficient goes down.

关 键 词：超临界 CFB锅炉 环形炉膛 内螺纹管 壁温 低质量流速 传热特性 

分 类 号：TK124[动力工程及工程热物理—工程热物理]