摘要
为了探究浮升力效应对超临界水传热性能的影响,本文建立了一个预测垂直上升光管内超临界水传热的3-D数值模型。利用该数值模型预测了系统压力为25 MPa,质量流速为600~800 kg·m^(-2)·s^(-1),内壁热负荷为400~500 k W·m^(-2)条件下超临界水的传热。分析了热负荷和质量流速对浮升力效应的影响,同时分析了浮升力效应对传热性能的影响规律。结果表明,当质量流速为800 kg·m^(-2)·s^(-1)时,浮升力效应导致了局部传热恶化,传热恶化发生后,传热系数迅速回升;而质量流速为600kg·m^(-2)·s^(-1)时,浮升力效应对传热性能的影响与热负荷有关。当质量流速为600 kg·m^(-2)·s^(-1),热负荷为400 k W·m^(-2)时,超临界水传热表现为传热强化;当质量流速为600 kg·m^(-2)·s^(-1),热负荷为500 k W·m^(-2)时,浮升力效应导致了局部传热恶化,传热恶化发生后,传热系数没有回升。
In order to investigate the influence of buoyancy effect on heat transfer characteristics of supercritical water,a 3-D numerical model was developed to predict the heat transfer of supercritical water in a vertical smooth tube.This numerical model was used to predict the heat transfer characterisitics of supercritical water under the conditions of system pressure of 25 MPa,mass flux of 600~800kg·m^(-2)·s^(-1),and inner wall heat flux of 400~500 k W·m^(-2).The influence of heat flux and mass flow flux on buoyancy effect and the influence of buoyancy effect on heat transfer characteristics were also analyzed.The results show that when the mass flow flux is 800 kg·m^(-2)·s^(-1),the buoyancy effect causes local heat transfer deterioration.After the heat transfer deterioration occurs,the heat transfer coefficient rebounds rapidly.When the mass flow flux is 600 kg·m^(-2)·s^(-1),the influence of buoyancy effect on heat transfer is related to heat flux.When the mass flow flux is 600 kg·m^(-2)·s^(-1)and the heat flux is 400 k W·m^(-2),supercritical water heat transfer shows enhanced heat transfer;when the mass flow flux is 600 kg·m^(-2)·s^(-1)and the heat flux is 500 k W·m^(-2),the buoyancy effect causes local heat transfer deterioration,and the heat transfer coefficient did not recover after the heat transfer deterioration occurred.
作者
杜晓成
周妍君
宋园园
杨冬
DU Xiaocheng;ZHOU Yanjun;SONG Yuanyuan;YANG Dong(State Key Laboratory of Multiphase Flow in Power Engineering,Xi'an Jiaotong University,Xi'an 710049,China)
出处
《工程热物理学报》
EI
CAS
CSCD
北大核心
2024年第7期2019-2025,共7页
Journal of Engineering Thermophysics
基金
国家重点研发计划项目(No.2022YFB4100303)。
关键词
超临界水传热
浮升力效应
传热恶化
数值模拟
supercritical water heat transfer
buoyancy effect
heat deteriation
numerical simulation
