An improved DNB-type critical heat flux prediction model for flow boiling at subcritical pressures in vertical rifled tube

作     者：Xie, Haiyan Yang, Dong Wang, Wenyu Wan, Li Li, Chunmei 

作者机构：Xi An Jiao Tong Univ State Key Lab Multiphase Flow Power Engn 28 Xianning West Rd Xian 710049 Shaanxi Peoples R China Nucl Power Inst China Sci & Technol Reactor Syst Design Technol Lab 328 Changshun AveSect 1 Chengdu 610231 Sichuan Peoples R China 

出 版 物：《INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER》 (国际传热与传质杂志)

年 卷 期：2019年第132卷

页      面：209-220页

核心收录：

学科分类：080702[工学-热能工程] 08[工学] 0807[工学-动力工程及工程热物理] 0802[工学-机械工程] 0801[工学-力学（可授工学、理学学位）] 

基　　金：National Key Research & Development Program of China [2016YFB0600201] 

主　　题：Bubble coalescence Rifled tube Departure from nucleate boiling Critical heat flux Numerical computation 

摘      要：Based on the near-wall bubble coalescence model and the structural characteristics of the rifled tube, improvements and optimization of the model for rifled tube were conducted. DNB-type CHF phenomenon in the rifled tube under subcritical and near-critical pressures was investigated by numerical calculation. A new CHF prediction model of flow boiling in rifled tube with low qualities was established and compiled by FORTRAN language. The model used the Staub model which considering the influence of the bubble contact angle to calculate the bubble detachment diameter. The surface friction coefficient of the rifled tube was calculated by the classical Kohler and Kastner formula. And a new critical void fraction of the wall bubbly layer co, correlation was proposed based on a large number of CHF experimental data. The present model was verified by the CHF look-up values and CHF experimental values. Based on the CHF experimental data of the rifled tube, three classic CHF prediction models and the present CHF model were evaluated, and it was found that the present modified CHF model has the highest prediction accuracy for the rifled tube, which is the best agreement with the experimental values, indicating that the present model is appropriate for DNB-type CHF prediction of the rifled tube. In this paper, the effects of pressure, mass flux and inlet fluid subcooled enthalpy on CHF were studied. It was found that, the effect of pressure and mass flux on CHF is obvious in the low quality region, with the increase of vapor quality, the influence of pressure and mass flux on CHF weakens. (C) 2018 Elsevier Ltd. All rights reserved.