汽-水换热器内流体诱导振动强化传热试验

提出利用换热器内流体诱导振动实现强化传热的方法 .在利用传热表面振动提高对流换热系数的同时 ,利用振动变形减少积垢 ,降低污垢热阻 ,实现了复合强化传热 .对管内外流体流动诱导弹性管束的振动特性、强化传热特性和污垢特性进行了试验研究     

石脑油加氢装置反应换热器内漏原因分析与解决措施

对石脑油加氢装置原料与反应产物换热器管束泄漏的发现经过和设备状况进行了描述。对管束泄漏的原因进行分析,认为主要是换热器壳程流体诱发的振动导致管束的破坏。对泄漏的管束提出了修复方案,并提出了生产实践中可以采取的防止换热器流体诱发振动的措施。     

列管式换热器管束防振问题探讨

列管式换热器管束的流体振动问题普遍存在于生产中,振动可能会造成换热器被破坏,进而影响装置的安全运行。对列管式换热器管束振动产生的原因、机理、研究现状进行了归纳和总结,讨论了旋涡脱落、湍流抖振、流体弹性不稳定性以及声共振等诱发列管式换热器振动的原因,并提出了预防振动的措施。以某煤化工项目的硫回收装置列管式换热器为实例,利用HTRI 7.0软件对管束振动进行了计算与分析,采用调整折流板间距、窗口不布管和折流板中间加支撑板等防振措施,消除了换热器的振动问题。装置投入运行后,列管式换热器无异常振动,达到了防振设计的目的。     

纵流式管束支撑物的结构及性能对比

纵流式管束支撑物使管壳式换热器壳程流体呈纵向流动，因而该类换热器具有传热效率高、压降小，有效消除了流体诱导振动等特点。本文阐述了纵流管束支撑物的结构变化对换热器综合性能的影响，为改进和优化管壳式换热器提供参考。     

管壳式换热器振动疲劳与强化传热技术评析

说明了利用流体诱导振动来强化传热和开发新型复合技术对换热器优化运行的重要性,并结合工程实际给出了振动疲劳的定义.分别对管壳式换热器壳程流体工作流速的一般分析方法和双程强化传热技术进行了评析.以换热器内能量平衡的观点为依据,给出管束长期在振动疲劳效应下工作时,计算壳程流体工作流速的一般流程.最后,确信必须通过应用新型传热元件、利用计算机技术、完善专家系统和丰富故障诊断经验,才能更加有效地利用流体激振的能量强化传热,进一步延长管束的使用寿命,使整个换热系统更好地服务于工业生产.     

折流杆换热器技术

折流杆换热器思想是1970年菲利浦石油公司在考虑消除现有的常规折流板式换热器中存在的破坏、流体诱导振动的措施时提出来的。早期的折流杆换热器设计采用了文(1～3)与管束轴线成45°角的椭圆形折流圈,既有水平支承杆又有竖直支承杆的相互交叉的一组折流圈置于每一管排之间。早期的折流杆换热器除解决了振动问题外,还显示出壳程压力降的减小和热力性能的提高,此后进一步的研究简化了折流杆换热器的设计思想,并建立了热力—水力设计预测方法文(4～6)。本文的目的是向读者介绍当前折流杆换热器设计技术的各个方面进展情况。     

广州溶剂厂甲醛废热锅炉振动与换热器振动机理[摘要]

本文扼要介绍了锅炉和换热器管子流体诱导振动(“流体在管外横向流过换热器管束的换热管时所激发的振动)的V.Kamen(卡曼)涡流分离(发散)、Owen湍流抖振、Connors流体弹性旋涡(弹性不稳定)三种主要的激振机理,以及气泡流弹状流、     

流体诱发换热器管束振动机理与防振

对管壳式换热器管束常见的振动破坏形式进行了归纳,对管束振动的机理进行了分析,并提出了相应的防振措施.     

纵流式换热器的结构研究进展

纵流式换热器具有传热效率高，压降小，有效消除流体诱导振动等特点，因而在石化等行业中的应用越来越多，其结构的发展主要表现为高效换热管的应用和管束支撑物的变化，阐述了纵流式换热器的特点，介绍了高效换热管和管束支撑物的结构及性能发展，指出了纵流式换热器的发展前景。     

折流杆换热器抗振性能的分析

对折流杆换热器抗振性能进行剖析,指出折流杆换热器的抗流体诱导振动性能取决于壳程流体流场的基本性质,而不在于其对管子的支承方式。进而指出折流杆换热器的抗振缺陷,并提出了相应的防振措施。     

汽液两相流中流体诱导振动的研究

流体横掠单管或管束时产生所谓诱导振动。这种诱导振动常常是引起热交换器损坏的主 要原困之一。P。idous幻s’“综述了由于流动所引起的诱导振动而导致热交换器损坏的50多种 情况。由仕可看出对诱导振动研究的必婴什。     

Two- and three-dimensional CFD-simulation of flow-induced vibration excitation in tube bundles

Two- and three-dimensional simulation models for the computation of flow-induced vibration of tube bundles subjected to single-phase cross-flow are applied for a full flexible tube row and a tube bundle. The flow-induced vibration is simulated with the CFD (Computational Fluid Dynamics) program STAR-CD in combination with a coupled solver for the differential equations of parallel vibrating tubes for two- and three-dimensional calculations. Additionally a coupled FEM (Finite Element Method) program is used for the three-dimensional simulation of different tube support conditions. The CFD program solves the Navier–Stokes equations with different k-models or an implemented kω-model for the unsteady turbulent viscous and incompressible flow field. The object of this project is to find a model, which describes the fluidelastic vibration excitation and enables an accurate computation of critical velocities in tube bundles comparable to those determined with the new design recommendation by K. Schröder and H. Gelbe, New design recommendations for fluidelastic instability in heat exchanger tube bundles, ASME AD-Vol. 53–2, Fluid-Structure Interaction, Aeroelasticity, Flow-Induced Vibration and Noise, 1997, Volume II, pp. 211-219 (s. a. Journal of Fluids and Structures, 13 (1999), to be published). Then it will be possible to investigate independently the influence of the structure data and the fluid properties on the onset of instability. The presented model is validated with experimental data and compared with existing models in the literature. Different grid discretizations of the flow field and turbulence models were tested for rigid and flexible tubes and the simulation results for the fluid forces, the pressure distributions and the onset of instability are compared with experimental data for a tube, a tube row and a tube bundle subjected to cross flow.     

换热器的防振设计

对换热器振动的机理和防振措施进行了归纳和介绍,运用换热器设计软件HTRI和TASC对某煤化工项目的换热器进行了防振设计,以此提出的相应的消除振动的原则和方法,有助于在工程设计中消除换热器振动。     

Numerical Simulation of Baffle-Supported Tube Bundle Vibration by the Method of Finite Differences

Tube bundles in heat exchangers are often damaged due to flow-induced vibrations. To simulate the fluid-structure interaction between the tubes and the flow field, which seems to be the only reliable way to predict flow-induced vibration of tube bundles, a coupled numerical solver for the governing Navier-Stokes equations of the flow field as well as for the structural response has to be used. Since commercial codes still require a large computational effort to calculate the fluid-structure interaction, one has to develop special program codes for certain technical problems. This paper deals with a numerical method to calculate the structural response of baffle-supported heat exchanger tubes due to outer forces such as flow and contact forces. The equations of motion for a cylindrical tube including torsional movement are developed. They are discretized in space by the means of Finite Differences and in time by Newmark′s method of constant acceleration. Non-linear frictional impact forces due to the baffle supports are introduced as additional line loads and line moments. Flow forces at this stage of development are modeled by simplified assumptions concerning vortex shedding. Numerical examples show the consistency of the calculated solutions. The algorithm is stable and converges for parameters of practical importance. Only little mathematical effort is needed compared to the Finite Element technique or modal analysis. A Navier-Stokes flow solver already developed can now be integrated into the vibration simulation code.     

列管式换热器的泄漏分析及防漏措施

不同类型的换热器在投入使用数月后,部分换热管与管板连接处发生泄漏.阐述列管式换热器泄漏的事例,从设计、制造、操作三方面分析泄漏的原因和应采取的预防措施,为今后换热器的设计、制造和使用提供参考.     

管壳式换热器流体诱导振动与防振

介绍了管壳式换热器流体诱导振动的现象、机理和防振措施 ,特别是介绍了目前最新的防振措施。     

固定折流板换热器的制造技术

固定管板换热器中折流板与筒体内壁焊接的结构能有效防止设备运行中管束的振动损伤,介绍了在对采用这种结构的某进口固定管板换热器进行国产化制造的过程中,由于结构空间限制所必须的制造技术。     

浅谈U型管换热器

文章通过对U型管换热器的结构特点和发展状况的一些介绍,并参考国内最新的研究成果,介绍了U型管换热器泄漏失效,U形管伸出管板的变形失效、换热管管束固有频率和换热器工作时产生的振动等等问题的分析及处理对策。从而为U型管换热器的设计、制造和使用,提供了依据和注意的事项。     

高效节能换热器在氮肥工业中的应用

描述了新型折流杆换热器的强化传热和降低壳层压力降的原理 ,它与传统折流板换热器相比 ,传热效率高 ,材料及能耗小。介绍了这种新型换热器在合成氨变换工段和尿素装置中的应用情况及所起的节能降耗作用 ,指出该高效节能换热器在设计和生产中的关键技术。