姓名：闫永帅      学号：sort of等于什么03        班级1班
International Journal of Heat and Mass Transfer
国际传热传质杂志
International Journal of Heat and Mass Transfer 70 (2014) 990–1002
A numerical model for combined heat and mass transfer in a laminar liquid falling film with simplified hydrodynamics
复合换热和传质层液体降膜与简化的流体力学数值模型
摘要
我们提出一个模型来描述：层流的流体降膜流过垂直等温金属板，同时吸收或释放热和质量的交换。我们开始的构想是建立课比较的模型应用简单假设，例如匀速和薄膜厚度不变。相反，我们接受一些影响像参数的变化和不同的热处理包括大体积的薄膜。另外，焓的变化由于什么。这些考虑的因素影响被讨论和比较。
这个数字化方案的获得通过利用N-B计划解决有限的不同的控制等式的构想来获得。因为与墙体和相态边界相邻的浓度梯度期望它很大，因此我们在不规则的格子上分割等式。模型的结果与建立的数据分析模型非常相适合。
我们发现减少不同的热处理方法包括主体的影响关系很小。然而，温度贡献作为其中的一个变化参数的影响在同一个数量级。而且，当在相同的条件下比较吸收和释放，吸收的质量传递速率比释放更高。
We present a model describing simultaneous heat and mass transfer of an absorbing or desorbing laminar liquid film flowing over a vertical isothermal plate. We start with a formulation which is comparable to established models by using simplifying assumptions such as homogeneous velocity and constant film thickness. In contrast to those, we allow for effects like change in properties and differential heat of solution within the bulk of the film. Additionally, enthalpy transport due to interdiffusion is accounted for. The impact of the considered effects are discussed and compared.
The numerical solution is obtained by utilising a Newton–Raphson scheme to solve the finit
e difference formulation of the governing equations. Since the temperature gradients adjacent to wall and phase boundary are expected to be large, we discretise the equations on an irregular grid. The results of the model agree very well with established analytical models.
It is found that the influence of release d differential heat of solution within the bulk is relatively small. However, the impact on the temperature distribution is in the same order of magnitude as the one of a change in properties. Moreover, when comparing desorption with absorption under equivalent conditions, the mass transfer rate during absorption is higher than during desorption.
1.引言
热质交换自然发生也包括各种工艺仪器。即使自然高效率系统已将进化啦，我们始终缺少这些过程的充分理解。在能量工程中，高效率的热质交换关键是在低消耗下获得高表现得热力循环。热动力循环，尤其是吸收冷量，大多依靠有效的交换因此要求用功的分析和设计。