热水解污泥在扭曲管中流动换热的数值模拟

发布时间：2018-01-12 23:28

本文关键词：热水解污泥在扭曲管中流动换热的数值模拟　出处：《同济大学学报(自然科学版)》2017年01期 　论文类型：期刊论文

【摘要】：采用数值模拟方法研究了热水解污泥在扭曲换热管中的流动换热特性,分析了扭曲管的强化传热机理.获得了扭曲管不同纵横比和扭曲比条件下的温度场与速度场分布,阐述了不同雷诺数对流动传热的影响.该结果与传统光滑圆管的流动换热特性进行了比较,研究结果表明,扭曲管产生的旋流和二次流可以有效地提高换热效率,但是也增加了流动阻力.另外,综合换热因子随着扭曲比的增大而减小,随着纵横比先增大后减小,在纵横比为1.96时达到最大.与传统光滑圆管相比,发现在低雷诺数(小于5 000)情况下扭曲换热管具有更高的换热效率.
[Abstract]:The flow heat transfer characteristics of hot water hydrolyzed sludge in twisted heat transfer tube were studied by numerical simulation. The enhanced heat transfer mechanism of the twisted tube is analyzed and the temperature and velocity distribution of the twisted tube under different aspect ratio and aspect ratio is obtained. The effects of different Reynolds numbers on the flow heat transfer are described. The results are compared with the flow heat transfer characteristics of traditional smooth circular tubes. The swirl and secondary flow produced by the twisted tube can effectively improve the heat transfer efficiency, but also increase the flow resistance. In addition, the comprehensive heat transfer factor decreases with the increase of the twist ratio, and then decreases with the increase of the aspect ratio. When the aspect ratio is 1.96, the heat transfer efficiency of the twisted tube is higher than that of the traditional smooth tube with a low Reynolds number (less than 5,000).
【作者单位】：同济大学污染控制与资源化研究国家重点实验室;
【基金】：污染控制与资源化研究国家重点实验室自主课题(PCRRY11010) 中央高校基本科研业务费专项资金国家自然科学基金青年科学基金(21307092,51106112)
【分类号】：X703
【正文快照】： 据估计,到2020年我国的污泥年产量将达到6 000万t(按照80%的含水率计算),污泥处理处置问题已经成为国内当前最为紧迫的环境问题[1].污泥处理工艺中,厌氧消化是目前国际上应用较为广泛且效果很好的污泥稳定化与资源化的处理工艺,同时也是国内近些年鼓励提倡的污泥处理工艺.针对

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