通道振动频率对超临界正癸烷裂解流动换热影响的数值研究  

Numerical study of influence of channel vibration frequency on flow and heat transfer of supercritical n-decane with pyrolysis reaction

作　　者：黄娜[1] 蒋云龙 王东涵 吴明婷 蒋雪莉 钟豫 HUANG Na;JIANG Yunlong;WANG Donghan;WU Mingting;JIANG Xueli;ZHONG Yu(School of Energy and Power Engineering,Northeast Electric Power University,Jilin 132012,Jilin,China;Liaoning Branch of Inc.,Huadian New Energy Group,Shenyang 110179,Liaoning,China)

机构地区：[1]东北电力大学能源与动力工程学院,吉林吉林132012 [2]华电新能源集团股份有限公司辽宁分公司,辽宁沈阳110179

出　　处：《化工学报》2025年第1期173-183,共11页CIESC Journal

基　　金：吉林省教育厅科研项目(JJKH20230113KJ);吉林省科技发展计划项目(YDZJ202301ZYTS268);东北电力大学青年博士科研助推计划项目(BSZT15202405)。

摘　　要：振动冷却通道内超临界正癸烷的裂解吸热流动过程因同时存在流场、温度场和物性场等多物理场间耦合作用,流动换热过程十分复杂。基于正癸烷裂解总包反应模型,对矩形振动通道内超临界正癸烷裂解流动换热过程进行数值研究,系统讨论通道振动频率对再生冷却通道流动换热性能的影响规律和作用机制。计算结果显示,通道振动会加强内部流体掺混,通道内二次流动随振动频率提高而增强,高频率振动引发的横向剪切对流体边界层产生扰动,使热侧近壁面边界层减薄,热壁的物理换热过程增强。然而,增强的物理换热降低了热壁表面正癸烷温度,使正癸烷裂解反应被推迟,化学热沉释放被延迟。不同振动频率下,裂解反应均在L/D>100处开始发生,在L/D=130处接近裂解反应速率峰值。与静止通道相比,振动通道热壁表面温度、传热系数及热壁表面正癸烷质量分数均呈不同特征的周期分布。研究结果可为运动通道内包含化学吸热反应的流动换热问题提供参考。The pyrolysis endothermic flow process of supercritical n-decane in the vibration cooling channel is very complicated due to the coupling of multiple physical fields including flow field,temperature field and physical property field.Based on the total package reaction model of n-decane cracking,a numerical study was conducted on the flow heat transfer process of supercritical n-decane cracking in a rectangular vibration channel,and the influence of channel vibration frequency on the flow heat transfer performance of the regeneration cooling channel and its mechanism were systematically discussed.The calculation results show that the channel vibration will strengthen the internal fluid mixing,the secondary flow in the channel will increase with the increase of vibration frequency,and the lateral shear caused by high frequency vibration will disturb the fluid boundary layer,thinning the boundary layer near the wall of the hot side,and strengthening the physical heat transfer process of the hot wall.However,the enhanced physical heat transfer reduces the n-decane temperature on the hot wall surface,delaying the n-decane cracking reaction and the release of chemical heat sink.Under different vibration frequencies,the cracking reaction starts at L/D>100,and reaches the highest cracking reaction rate at L/D=130.Compared with the static channel,the surface temperature,heat transfer coefficient and mass fraction of n-decane on the hot wall surface of the vibrating channel have different characteristics of periodic distribution.The research results can provide reference for the flow heat transfer problem involving chemical endothermic reaction in the movement channel.

关 键 词：超临界正癸烷 通道振动 对流 化学反应 计算流体力学 

分 类 号：TQ021.3[化学工程]