Spherical dimples in cylindrical tubes enhance heat transfer and lead to a more uniform radial temperature profile. To combine these positive properties with a low pressure drop, a single dimple was optimized through a genetic algorithm. Multiple design parameters such as width, height, and curvature of the dimple were investigated. Heart‐shaped dimples outperformed spherical dimples. Three‐dimensional reactive simulations of a Millisecond propane steam cracking reactor showed that both the spherically dimpled and the heart‐shaped dimpled coil positively affect the light olefin selectivity, mainly through an increase in propylene selectivity. The optimized dimples could reduce the high pressure drop penalty by 21%. Run length simulations proved that the optimized dimple shape results in an additional run length extension of 18%. Next to this, the fuel rate consumption can be decreased by 6% compared to a bare coil, which could theoretically result in 4% less CO₂ emissions.

中文翻译：

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基于计算流体力学的凹坑式蒸汽裂化反应器优化，可减少二氧化碳排放量

圆柱管中的球形凹痕增强了热传递并导致更均匀的径向温度分布。为了将这些积极特性与低压降相结合，通过遗传算法对单个酒窝进行了优化。研究了多个设计参数，例如酒窝的宽度，高度和曲率。心形酒窝的性能优于球形酒窝。毫秒级丙烷蒸汽裂化反应器的三维反应性仿真表明，球形凹坑和心形凹坑都主要通过提高丙烯的选择性对轻质烯烃的选择性产生积极影响。优化的酒窝可以将高压降损失降低21％。游程长度仿真证明，优化的凹坑形状会导致游程长度额外增加18％。在此旁边₂排放。