过冷沸腾起始点预测关系式研究

本文认为过冷沸腾起始点为一个流程段,起于气泡开始汽化点,终于气泡脱离气穴点。基于这一假设建立了更为符合实际的过冷沸腾起始点气泡模型,在此基础上,用唯象方法获得了气泡半径公式及壁面过热度与热流密度关系式,并与实验数据进行了比对,其误差分布更加合理。

Investigation of the onset of sub-cooled boiling prediction correlation

Background:The predicted superheat degree of the onset of boiling point is always lower than that of experiment. Hence, a new model is necessary for the accuracy prediction in engineering calculation.Purpose: This study aims to investigate the reason of deviation and bring out a new prediction model, which can be used in engineering analysis directly and simply.Methods: Based on the vapor growth model and the viewpoint of force balance, the onset of fluid vaporization (OFV) and onset of nucleate boiling (ONB) points are separated. Thereby a new analysis model is built and combined with phenomenological analysis method.Results: The formulas to predict the bubble radius and the relationship of the wall superheat degree and heat flux at OFV and ONB are obtained. Compared with the existing experimental data, the error distribution is more rational.Conclusion: The presented model can improve predicted results for distinguishing OFV and ONB under the limitation of experimental measuring equipment. However, more experimental data validation is necessary.