蒸汽加热垂直矩形窄通道内流型与局部换热特性研究  

Study on Flow Patterns and Local Heat Transfer Characteristicsin Steam Heated Vertical Narrow Rectangular Channel

作　　者：顾晟杰 陶乐仁[1,2] 金程 居一伟 赵谢飞 GU Shengjie;TAO Leren;JIN Cheng;JU Yiwei;ZHAO Xiefei(School of Energy and Power Engineering,University of Shanghai for Science and Technology,Shanghai 200093,China;Shanghai Key Laboratory of Multiphase Flow and Heat Transfer in Power and Engineering,Shanghai 200093,China)

机构地区：[1]上海理工大学能源与动力工程学院,上海200093 [2]上海市动力工程多相流动与传热重点实验室,上海200093

出　　处：《动力工程学报》2024年第10期1515-1524,共10页Journal of Chinese Society of Power Engineering

基　　金：上海市动力工程多相流动与传热重点实验室研究资助项目(2019KJFZ201)。

摘　　要：为了明确竖直矩形窄通道内各阶段流动沸腾的换热特性,优化换热器性能,以去离子水为工质,对尺寸为1400 mm×250 mm×2.75 mm(高×宽×深)的蒸汽加热垂直矩形窄通道内流动沸腾流型与局部换热特性进行实验研究。将由实验数据得到的流型图与不同加热条件下的现有流型图进行了对比分析。结合流型变化分析了进口温度、质流密度、加热功率对局部换热特性的影响,并基于对实验数据的参数分析,得到适用于该实验工况下的新流动沸腾传热关联式。结果表明:入口温度的升高对提升核态沸腾段的换热有积极作用,而在进入搅拌流阶段后,其对局部传热系数的影响很小;质流密度增加会降低核态沸腾阶段的局部传热系数,提升液膜流动蒸发区的局部传热系数;随着加热功率的增加,局部传热系数的峰值呈现左移的趋势;新的传热关联式能很好地预测该实验工况下蒸汽加热垂直矩形窄通道内流动沸腾的局部传热系数。In order to clarify the heat transfer characteristics of flow boiling at each stage in vertical narrow rectangular channel and optimize the performance of the heat exchanger,the experimental study of the flow pattern and local heat transfer characteristics in steam heated vertical narrow rectangular channel with dimensions of 1400 mm×250 mm×2.75 mm(height×width×depth)was carried out,using deionized water as the working medium.The experimental flow patterns were compared with the existing flow patterns under different heating conditions.The effects of inlet temperature,mass flux and heating power on the local heat transfer characteristics were analyzed combined with the flow pattern variations.Based on the parametric analysis of the experimental data,a new flow boiling heat transfer correlation formula was obtained,which was applicable to the experimental conditions.Results show that the increase of inlet temperature has positive effect on heat transfer at nucleate boiling section,while the effect on the local heat transfer coefficient is small under churn flow phase.The increase of mass flux decreases the local heat transfer coefficient in nucleate boiling stage and enhances the local heat transfer coefficient in the evaporation zone of liquid film flow.The peak of the local heat transfer coefficient shows a tendency to shift to the left as the heating power increases.The new heat transfer correlation formula can well predict the local heat transfer coefficient of flow boiling in the steam heated vertical narrow rectangular channel under experimental conditions.

关 键 词：窄通道 流动沸腾 可视化 换热特性 蒸汽加热 

分 类 号：TK124[动力工程及工程热物理—工程热物理]