Subcooled boiling flow is a typical phenomenon of a high efficiency of heat transfer in the nuclear reactor. Bubble characteristic sizes are important parameters for the mechanism investigation of subcooled boiling flow. Compared to the empirical correlation and force analysis model, the heat balance model is an effective method to describe the growth of bubble and calculate the bubble maximum diameter. After a wide investigation of the law of bubble growth, some researchers concluded that the bubble diameter would increase all the time during the process. However after a detailed mathematical analysis by use of Squeeze Theorem, new model is developed for the bubble growth model according to heat balance theory in this paper. Compared to the traditional Unal's model, new model indicates the existence of local bubble maximum diameter during the bubble growth's process. In addition, a key group value is provided for the area ratios of different heat fluxes. Several databases are used for validation of the new model. The errors are around 20% which show the accuracy of the new method.

过冷沸腾流是核反应堆传热效率高的典型现象。气泡特征尺寸是研究过冷沸腾流动机理的重要参数。与经验相关性和受力分析模型相比，热平衡模型是描述气泡生长和计算气泡最大直径的有效方法。在对气泡生长规律进行广泛调查后，一些研究人员得出结论，在此过程中，气泡直径会一直增加。然而，在利用挤压定理进行详细的数学分析后，本文根据热平衡理论建立了气泡生长模型的新模型。与传统的 Unal 模型相比，新模型表明在气泡生长过程中存在局部气泡最大直径。此外，还为不同热通量的面积比提供了一个关键组值。几个数据库用于验证新模型。误差约为 20%，这表明新方法的准确性。