ABSTRACT

A numerical investigation of the condensing flow of isobutane inside microchannel has been performed. Impact of mass flux, hydraulic diameter, and vapor quality on the heat transfer rate and pressure drop is determined. To this purpose, steady-state numerical simulations of condensation flow of isobutane have been performed at mass fluxes ranging from 200 to 600 kg/m²s inside a single circular microchannel with varying diameter. Similar to the usual operation conditions, the simulations have been conducted for constant saturation temperature and constant wall heat flux as the thermal boundary condition. The proposed model has been based on the volume of fluid approach, which is an interface tracking method. The Lee model has been used to model the phase change mass transfer at the interface. A verification study has been performed by comparing the proposed model results with the experimental and visual data available in the literature. The currently available correlations are assessed by comparisons with the simulation results. Based on the presently validated simulations, a new correlation has been proposed for the heat transfer coefficient and pressure drop of isobutane condensing flow inside small-scale channels. This is a novel aspect of the present paper, since such a correlation does not yet exist.

摘要

对异丁烷在微通道内的冷凝流动进行了数值研究。确定了质量通量，水力直径和蒸汽质量对传热速率和压降的影响。为此，已经在质量通量为200至600 kg / m ^2的范围内进行了异丁烷冷凝流的稳态数值模拟。在直径可变的单个圆形微通道内。与通常的操作条件相似，已经针对恒定的饱和温度和恒定的壁热通量作为热边界条件进行了仿真。所提出的模型基于流体体积方法，这是一种界面跟踪方法。Lee模型已用于对界面处的相变传质建模。通过将建议的模型结果与文献中提供的实验和视觉数据进行比较，进行了验证研究。通过与仿真结果进行比较来评估当前可用的相关性。根据目前已验证的模拟，对于小规模通道内异丁烷冷凝流的传热系数和压降提出了一种新的相关性。这是本文的一个新颖方面，因为尚不存在这种相关性。