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振荡流通过内插螺旋翅片管传热特性的数值模拟

2014年第33卷第7期CHEMICAL INDUSTRY AND ENGINEERING PROGRESS ·1691·

化工进展

振荡流通过内插螺旋翅片管传热特性的数值模拟

屈晓航,田茂诚,冷学礼

(山东大学能源与动力工程学院,山东济南 250061)

摘要:振荡折流换热器广泛应用在包含传热传质过程的化工过程中,本文对管内插入螺旋翅片的振荡折流换热器进行了三维非稳态数值模拟,模拟在斯特劳哈尔数St=2,4,8和振荡雷诺数Re o=20,40,80范围内进行。通过作出瞬时三维流线,以观察流动状态随时间变化规律,发现其中有纵向涡和横向涡的周期性形成和脱落;得到了圆管周向局部传热系数随时间变化规律,以及不同振荡参数(St和Re o)下周向平均传热系数随时间的变化规律。结果表明:局部传热系数沿周向不均匀分布,并在翅片斜对面达最大;周向平均传热系数随时间周期性变化,时间平均传热系数随振幅增大而增大,但受频率影响却不明显;在本文讨论的参数范围内,平均传热系数最大可达圆管层流的4倍。

关键词:振荡折流换热器;螺旋翅片;强化传热;计算流体力学

中图分类号:TK 124 文献标志码:A 文章编号:1000–6613(2014)07–1691–06

DOI:10.3969/j.issn.1000-6613.2014.07.006

Numerical simulation of heat transfer of oscillatory flow in a tube fixed

with spiral fins

QU Xiaohang,TIAN Maocheng,LENG Xueli

(School of Energy and Power Engineering,Shandong University,Jinan 250061,Shandong,China)Abstract:Oscillatory baffled heat exchangers (OBHEs) are widely used in chemical processes involving heat or mass transfer. OBHE with spiral fins inserted was simulated using the three dimensional unsteady method in the range of Strouhal number St=2,4,8 and oscillatory Reynolds number Re o=20,40,80. Instantaneous three dimensional stream lines were drawn to show the change of flow status with time,and periodic formation and shedding of spanwise and streamwise vortexes was observed. The changes with time of peripheral local heat transfer coefficients (HTCs)and peripherally averaged HTCs with different oscillatory parameters (St and Re o) were obtained. The local HTCs were not distributed uniformly peripherally and a maximum value was reached at the diagonally across position of fins. Peripherally averaged HTC varied with time periodically and time averaged HTC increased with increasing amplitude,but hardly changed with frequency. In the range covered by this work,averaged HTC could be four times higher than that of tube laminar flow.

Key words:oscillatory baffled heat exchanger;spiral fins;enhancement of heat transfer;CFD

振荡折流换热器主要利用振荡流与挡板共同作

用下的强化传热传质效果,因具有把间断传热或传质过程转变为连续传热传质过程的能力,其在化工过程中得到广泛应用[1-2]。虽然平直通道中流体的振荡对强化传热作用不明显[3],但在加入各种阻碍流体运动的障碍物的情况下,振荡流能显著强化换收稿日期:2014-01-06;修改稿日期:2014-01-17。

基金项目:山东省科技攻关(2008GG10007009)及山东科技发展计划(2012GGX10421)项目。

第一作者:屈晓航(1989—),男,博士研究生,研究方向为强化传热与节能技术。E-mail quxiaohang@https://www.wendangku.net/doc/3013708626.html,。联系人:田茂诚,教授,博士,研究方向为强化传热与节能技术。E-mail tianmc65@sdu. https://www.wendangku.net/doc/3013708626.html,。

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