RESEARCH ON PREDICTION METHODS OF HEAT TRANSFER COEFFICIENT AND CRITICAL HEAT FLUX IN BOILING OF MULTICOMPONENT MIXTURES

多组分混合物沸腾传热系数和临界热通量预测方法研究

• 批准号: 14550187
• 负责人: FUJITA Yasunobu
• 金额: $ 2.43万
• 依托单位: KYUSHU UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2002
• 资助国家: 日本
• 起止时间: 2002 至 2003
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-14550187/
• 关键词: Multicomponent mixture; Nucleate boiling; Heat transfer coefficient; Critical beat flux; Correlations; Marangoni number; マランゴニ数; 多成分流体; 混合液; 核沸騰熱伝達; 熱伝達係数の予測法; 限界熱流束の予測法; 熱伝達の予測法; Multicomponent mixture; Nucleate boiling; Heat transfer coefficient; Critical beat flux; Correlations; Marangoni number; マランゴニ数; 多成分流体; 混合液; 核沸騰熱伝達; 熱伝達係数の予測法; 限界熱流束の予測法; 熱伝達の予測法

(1)Heat transfer coefficients in nucleate boiling of mixtures were measured for various two-component mixtures and three-component mixtures. It was found from the measured data analysis that the reduction of heat transfer coefficient compared to the ideal coefficient estimated from heat transfer coefficient of mixture components is deeply related to the boiling range. Thus by taking into account the boiling range as a key parameter the heat transfer correlation was developed. The developed correlation succeeded to reproduce the measured heat transfer coefficients of two-and three-component mixtures within ±25% errors.(2)Measurement of critical heat flux was performed for seven two-component mixtures. It was found that critical heat flux is either increased or decreased in 'a comparison of the ideal critical heat flux interpolated between the critical heat fluxes of mixture components. Positive mixtures provided the increased critical heat flux, while negative mixtures gave the decreased critical heat flux. Such a behavior of critical heat flux depending on the mixture property was concluded as the result of Marangoni force acting on thin film surface formed between the coalesced bubble and the heating wall. In order to realize such critical heat flux mechanism of mixtures the dimensionless Marangoni number was introduced, resulting in successful development of an empirical correlation for critical heat flux in mixture boiling.

（1）测量混合物核沸腾中的传热系数，用于各种两组分组和三组分混合物。从测量的数据分析中发现，与混合组件的传热系数相比，传热系数的降低与沸腾范围密切相关。通过考虑到沸腾范围作为关键参数，就开发了传热相关性。开发的相关性成功地重现了在±25％误差范围内的两个和三组分混合物的测得的传热系数。（2）对七个两组分组进行了临界热通量的测量。发现在混合成分的临界热通量之间插值的理想临界热通量的比较中，临界热通量会增加或减少。阳性混合物提供了增加的临界热通量，而负混合物的临界热通量下降。根据混合物特性的不同，临界热通量的这种行为是由作用于合并气泡和加热壁之间的薄膜表面上的Marangoni力的结果。为了实现这种关键的热通量机制，引入了无量纲的Marangoni数量，从而成功发展了混合沸腾中临界热通量的经验相关性。