摘要
界限质量流速G0是直流锅炉垂直管圈水冷壁设计的一个关键参数。当垂直管圈水冷壁支管内的质量流速小于G0时,水冷壁将呈现正流量响应特性。为了系统研究G0的影响因素及它们对G0的影响规律,文中建立亚临界/超临界压力条件下垂直管内工质流动压降的计算模型,推导出均匀受热垂直上升管内G0的解析表达式,揭示了界限质量流速与加热条件和管子结构参数的函数关系。在此基础上,结合两相流流动特性参数的经验关联式,系统分析G0在不同条件下的变化规律。结果表明,进出口工质温度、工质压力、管子内径和沿程摩阻系数、管长对G0均有一定影响。在几何结构不变时,降低工质进、出口温度或者提高工质工作压力都会使得G0增大。在进、出口工质温度和工作压力不变时,减小管子内径、增大沿程摩阻系数或是减小管长会使得G0减小。
Critical mass flux(G0) is one of the important parameters in the design of once-through boilers with vertical water wall. The vertical water wall will show positive flow characteristic when the mass flux is less than G0. However, the study of the influence factors of G0 is limited in the open literature. Theoretical derivation based on classical pressure drop model was performed to investigate the pressure loss variation characteristics of water flowing upward in a uniformly heated tube under supercritical/subcritical pressure.An analytical expression of G0 was derived as the function of tube structure parameters and operating conditions. G0 values under different conditions were obtained by substituting some empirical correlations for two-phase flow parameters into the analytical expression. Based on the calculation results, the influences of tube inlet and outlet temperature, operating pressure, tube inner diameter, friction factor and tube length on G0 were analyzed in detail.
作者
唐国力
顾君苹
吴玉新
李舟航
吕俊复
刘青
TANG Guoli;GU Junping;WU Yuxin;LI Zhouhang;LYU Junfu;LIU Qing(Key Laboratory for Thermal Science and Power Engineering,Ministry of Education (Tsinghua University),Haidian District,Beijing 100084,China;State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization (Kunming University ofScience and Technology),Kunming 650093,Yunnan Province,China)
出处
《中国电机工程学报》
EI
CSCD
北大核心
2019年第8期2357-2364,共8页
Proceedings of the CSEE
基金
国家重点研发计划(2016YFB0600201)~~
