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波纹管换热器是一种新型的强化传热节能型高效换热设备,它是在传统的列管式换热器的基础上,应用强化传热理论,对传统的各类换热器的突破,具有换热效率高、耐腐蚀、不易结垢、运行安全平稳等优点。在相同换热面积的情况下,波纹管换热器的换热量是管壳式换热器的2~3倍。 相似文献
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分析波纹管式换热器的强化传热理论机理和换热特性;试验研究了波纹管的强度与刚度;对比分析了波纹管换热器所具有的经济性。 相似文献
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分析波纹管式换热器的强化传热理论机理和换热特性;试验研究了波纹管的强度与刚度;对比分析了波纹管换热器所具有的经济性。 相似文献
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郑金专 《硫磷设计与粉体工程》2006,(4):40-42
针对传统的管壳式换热器在高沸点、高凝固点物系中使用存在的问题,介绍了以波纹管代替光滑直管的管壳式波纹管换热器强化传热的原理和结构特点,实践证明该新型换热器的传热系数提高了35%。 相似文献
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换热器传热强化在换热网络中的应用可以解决现有换热网络改造中的瓶颈问题,在热回收系统配置没有过多结构改造的条件下,可以达到明显的节能及降低成本的目的;同时,在换热网络设计中,换热器传热强化技术的应用可以降低设备投资,实现更好的经济效果。本文首先通过文献检索数据说明了在换热网络改造和设计中考虑传热强化技术的研究在近5年得到了研究者的关注。然后概述了管壳式换热器传热强化的基本原理及主要方式,分析了传热强化技术的应用对换热器传热性能的影响,系统总结了管壳式换热器传热强化技术的分类和强化效果。进一步从设计和改造两个方面,对换热网络优化中考虑管壳式换热器传热强化的应用研究进行了综述,展示了传热强化对换热网络设计和改造的效果和优势。最后对下一步的研究进行了展望,指出可进一步探究换热器传热强化设备几何尺寸和换热网络同步优化、传热强化和换热器详细设计同步优化等。 相似文献
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不连续双斜向内肋强化换热管性能 总被引:1,自引:2,他引:1
引言管壳式换热器在石油化工、能源动力、造纸、制药等领域应用十分广泛,换热强化对于其节能降耗具有十分重要的意义.近30年研制开发出几十种强化换热管,例如螺旋槽管、波纹管和翅片管等,并得到了比较成功的应用.但相关的研究多数仍然停留在经验的基础上,即研究者根据其经验设计出某种具体的强化技术,然后通过实验和数值计算归纳出适用于一定范围的经验关联式.因此,传热强化研究目前仍属于技术领域[1],研究人员通常所采用的经验性的研究方法不可避免存在着一定的局限性.过增元等[2]提出了一种新的强化换热理论———对流换热场协同理论,为对… 相似文献
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xperimental Study of Heat Transfer Enhancement and Friction Loss Induced by Inserted Rotor-assembled Strand (I) Water
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The single-phase pressure drop and heat transfer in a rotor-assembled strand inserted tube were measured using water as the working fluid. Experiment using a smooth tube was carried out to calibrate the experimental system and the data reduction method. In the experiment, fixed mounts were used to eliminate the entrance effect. The experimental results of smooth tube show that employment of fixed mounts leads to a visible bias of friction factor at relative low Reynolds numbers, although it does not significantly affect the Nusselt numbers. The measured data of inserted tube reveal that rotor-assembled strand can significantly improve heat transfer with the Nusselt number increased by 101.6%-106.6% and the overall heat transfer coefficient increased by 58.1%-67.4% within the Reynolds number range of 20000 to 36000. Meanwhile, friction factor increases by 52.2%-84.2% within the same Reynolds number range. The correlations of Nusselt number and friction factor as function of the Reynolds number and Prandtl number were determined through multivariant linear normal regression. 相似文献
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Based on finite volume method, the pressure drop and heat transfer characteristics of one smooth tube and ten different axisymmetric corrugated tubes, including two with uniform corrugation and eight with non-uniform corrugation, have been studied. A physical model of the corrugated tube was built, then the numerical simulation of the model was carried out and the numerical simulation results were compared with the empirical formula.The results show that: the friction factor decreases with the increase of Reynolds number ranging from 6000 to 57000, the value of which in the corrugated tubes with non-uniform corrugation(tube 03–10) are smaller than those with uniform corrugation(tube 01–02). The geometry parameters of tube(01) have advantages on the heat transfer enhancement in low Reynolds number flow region(from 6000 to 13000) and tube(07–08)have advantages on the heat transfer enhancement in high Reynolds number flow region(from 13000 to 57000). The vortex, existed in each area between two adjacent corrugations called second flow region, is the root of the enhancement on heat transfer in the corrugated tubes. The effectiveness factor decreases with the increasing of Reynolds number and the performances of the corrugated tubes with pitch of 12.5 mm have advantages than these of 10 mm under the same corrugation geometric parameter. 相似文献
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Dieter Traub 《Chemical Engineering and Processing: Process Intensification》1990,28(3):173-181
The influence of turbulence intensity on heat transfer and pressure drop in tube bundles was measured in an open wind tunnel. The bundles consisted of one to three rows of plain tubes with in-line and staggered tube arrangements. The vertically arranged tubes were heated by saturated steam, condensing inside, and cooled outside with air in cross-flow. The turbulence intensity behind different grids varied in the air stream between 0.8% and 25%, and the air-side Reynolds numbers ranged from 1.5 × 104 to 1.5 × 105. The enhancement of the heat transfer coefficients for the bundles is due to an increase in the level of turbulence and also to a decreasing number of rows. The increase in the Nusselt number is about 42% for a single row and about 14% for a tube bundle with three rows.
From the pressure drop experiments it follows that over a wide range of Reynolds numbers the drag coefficient is almost independent of the inlet turbulence intensity.
In this paper the experimental results for single rows and for bundles with three rows are presented. The influence of the transverse and longitudinal pitch to diameter ratio on heat transfer and pressure drop is discussed. 相似文献
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通过实验研究了波纹形内翅片换热管的对流换热和阻力特性,拟合了所测Re范围内对流换热和阻力实验关联式,并运用相同质量流量、相同泵功率、相同阻力降这三种准则比较了该翅片管与普通光管之间的传热效果。结果表明,这种波纹形内翅片管有较强的换热效果,特别是在低Re条件下,强化效果更加明显。 相似文献
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试验研究了新型环保工质HFC245fa在光管与强化换热管管束上的冷凝换热特性。试验管束由4列排深为5排的列管构成,换热管公称外径为19.05mm、有效换热长度为1000mm。试验中,通过改进的Wilson图解法获得强化换热管水侧对流传热系数,利用2接点温差电偶测试蒸气与冷却水温差(±0.025℃),利用热电偶通过小周期标定法获取试验管进出水温差(±0.01℃);考察了冷凝温度、热通量对冷凝换热的影响。研究结果表明:HFC245fa在光管单管外冷凝传热系数与Nusselt模型预测值一致性较好;同热通量下,强化换热管单管上的冷凝传热系数为光管的13.5倍;光管管束上的试验结果比Nusselt管束模型预测值高20%~50%;强化管冷凝换热性能受作用热通量的影响较大。试验结果对工质与新管材推广、应用具有指导意义。 相似文献
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