硫酸转化系统中新型换热器的强化传热研究

Heat Transfer Augmentation of New Heat Exchanger in Conversion System of Sulphuric Acid Plant

针对硫酸转化系统中气体换热器的特点,提出并分析了一种新型的传热强化元件——旋流片作为管束间支撑物的流动与传热特性。在实验研究基础上,应用周期性单元流道模型,数值模拟了空心环和旋流片支撑时的湍流流动和传热性能。结果表明,空心环和旋流片均增强了换热,旋流片能迫使流体做强烈的三维螺旋运动,增强湍流度,同时使流体冲刷壁面,减薄边界层,所以换热效果优于空心环。旋流片产生的自旋流具有低阻高效的优势,其传热强化因子大于空心环。

In light of feathers of gas heat exchanger in conversion system of sulphuric acid plant, twisted- leaf tube bundle support was conducted and investigated as a new type of heat transfer augmentation element, including flow and heat transfer characteristics. Based on experimental analysis, a shell--side periodic unit channel model was developed to conduct numerical simulation. The results demonstrate that both types of supports can enhance heat transfer. Twisted--leaf support has better heat transfer enhancement than ring support, because it can produce helical motion promoting turbulent intensity and enhance heat transfer more effectively. Twisted leaf has a better integrated thermal performance resulting from its high heat transfer efficiency and low pressure loss in its free swirl zone.