The purpose of this study is to analytically assess the local heat transfer coefficients by using the local bubble properties, which include the local gas holdup, bubble pass frequency, bubble chord length, and axial bubble velocity in a bubble column reactor. Therefore, for the first time, a combined probe that consists of a fast-response heat transfer coefficients probe and an advanced four-point optical probe was used for simultaneously measuring the heat transfer coefficients and the bubble properties, respectively. A new model, which has been developed, applied to estimate the contact time ($\tau$) between the thin liquid film on the heating surface and the bulk liquid, which is one of the two parameters required in the mechanistic equation for determining the heat transfer coefficients. The experiments were conducted using a Plexiglas bubble column of 0.44 m diameter and 3.66 m height. Analytically, the consecutive film and the renewal mechanistic model of the unsteady-state surface have been used to calculate the rate and coefficients of the heat transfer. Results illustrate that the heat transfer coefficients is significantly affected by the local bubble properties and their distributions over the surface of the heat sensor. However, the contact time (τ) is a function for the local gas holdup and the bubble pass frequency. Thus, the variation in the local heat transfer coefficients with the contact time is due to the bubble pass frequency and the local gas holdup. A very good agreement, within 13%, was found between the predicted and the experimental values of the heat transfer coefficients, even though the model overpredicts the heat transfer coefficients at all the evaluated conditions.

这项研究的目的是通过使用局部气泡特性来分析评估局部传热系数，这些特性包括局部气体持留量，气泡通过频率，气泡弦长和气泡塔反应器中的轴向气泡速度。因此，首次使用由快速响应传热系数探针和高级四点光学探针组成的组合探针分别同时测量传热系数和气泡特性。已开发出一种新模型，用于估算接触时间（$\tau$）在加热表面上的液体薄膜和散装液体之间），这是确定传热系数的机械方程式所需的两个参数之一。实验使用直径为0.44 m，高度为3.66 m的Plexiglas气泡柱进行。在分析上，非连续表面的连续膜和更新机制模型已用于计算传热的速率和系数。结果表明，传热系数受局部气泡特性及其在热传感器表面的分布的影响很大。然而，接触时间（τ）是局部气体滞留率和气泡通过频率的函数。因此，局部传热系数随接触时间的变化归因于气泡通过频率和局部气体滞留率。即使模型在所有评估条件下都过度预测了传热系数，在传热系数的预测值与实验值之间也发现了很好的一致性，在13％以内。