A proper design is one that is absolutely safe against failure of tubes due to flow induced vibration. And one more question, warning appears tema rhov2 criteria not accepted. Crossflow induced vibration due to shell side fluid flow around the tubes bundle of shell and tube heat exchanger results in tube vibration. Crossflowinducedvibrations in heat exchanger tube bundles. Experimental study on crossflow induced vibrations in. Vortex induced vibration is the major consideration since heat exchanger are designed keeping in mind the threshold for fluidelastic instability. A heat exchanger tube bundle showing some window and interior tubes. Flow induced vibration and noise with particular reference to heat exchanger tube systems r. These are turbulent pressure pulsations see turbulent flow, vortex initiation and separation from tubes in crossflow see crossflow, hydroelastic. The drag and lift forces play a significant role in flow induced vibration. Heat exchanger, flow induced vibration, tema, htri. Dye proceedings of the institution of mechanical engineers, conference proceedings 2006 180.
Differentiating between acoustic and flowinduced vibration. Trans icheme, vol 80, part a, april 2002 flow induced vibration in heat exchangers 227 referring to figure 1 it may be seen that for small bullet6 owvelocities there is relatively little vibration compared to thesignibullet5 cant vibration that starts at a bullet6 ow velocity. The fluids may be separated by a solid wall to prevent mixing or they may be in direct contact. This is a major concern of designers, process engineers. Crossflowinducedvibrations in h eat exchanger tube bundles. Excessive flow induced vibrations may cause tube failures by fretting. Generally, there are several main mechanisms for flowinduced vibration in heat exchangers as follows. The main reason for tube failure due to flow induced vibration is increased size of. Flowinduced vibration analysis of a shell and tube heat exchanger is an integral element of its thermal design. Flow induced vibration tests using water as the shell side medium were conducted on a shell and tube exchanger with single segmental baffles and various tube layouts.
An improvement to the quasisteady model with application to. A survey on vortex induced vibration of cross flow heat. Over the past few decades, the utility industry has suffered enormous financial losses because of vibration related problems in steam generators and heat exchangers. Various methods for predicting and solving tube and acoustic vibration problems in heat exchangers in cross flow are presented. Noise and vibration analysis of a heat exchanger the. Flowinduced vibration in heat exchangers request pdf. Request pdf flow induced vibration in heat exchangers heat exchanger tube bundles may fail due to excessive vibration or noise.
Vibrational analysis of a shell and tube type of heat exchanger in. Mechanics of flowinduced vibration failures of heat exchangers caused by flowinduced vibration are mainly in terms of the detriments of heat exchanger tubes. As part of this ongoing program, tube vibrations are systematically being investigated in a series of shellside water flow tests performed with a test exchanger. As many previous studies were considered laminar flow re flow for which re 4000. The other mechanisms of vibrations, namely, vortex.
Flowinduced vibration in shellandtube heat exchangers with. Vortex shedding when shell side fluid flows across heat exchanger tubes. Request pdf flowinduced vibration in heat exchangers heat exchanger tube bundles may fail due to excessive vibration or noise. Flowinduced vibrations lead to fretting wear damage in heat exchangers, steam generators, and in fuel assemblies in nuclear power generation plants and tube support sites are the most favourable for fretting damage in these system 1 2 3. Wambsganss argonne national laboratory, argonne, illinois, 60439. For instance, the slender bodies of aircraft fuselages, missiles, and rockets, and the main bodies of industrial smokestacks, power transmission cables, telephone wires, oil pipelines, reactor fuel rods, heat exchanger tubes, and offshore structures, as well as. Potentially damaging flow conditions may result in flow induced vibration fiv tube failures due to.
Flowinduced vibration in shellandtube heat exchangers with doublesegmental baffles. Jul 08, 2016 ppt on failure analysis of shell and tube heat exchangers 1. Moretti, why can the prediction of heat exchanger vibrations fail. According to the literature, many incidents of failure due to apparent. However, after many years of service such remorseless low level vibration will produce tube wall thinning, due to fretting, which may be unacceptable in a highintegrity heat exchanger. Temperature control by heat exchanger incorporating with. Flowinduced vibration of heatexchanger tube bundles often causes serious damage, resulting in reduced effi ciency and high maintenance costs. Mechanical design of shellandtube heat exchangers with flow. Design of shellandtube heat exchangers to avoid flow.
A computer software was developed for the mechanical design of shellandtube heat exchangers with flow induced vibration checks based on tubular exchanger manufacturing association inc. They are widely used in space heating, refrigeration, air conditioning, power stations, chemical plants, petrochemical plants, petroleum. Flowinduced vibration of heatexchanger tube bundles often causes serious damage, resulting in reduced ef. It involves checking for the most probable modes of acoustic vibration and suggesting possible design modifications to mitigate or eliminate acoustic vibration should it be predicted. Clearly, such extreme causes of vibration must always be avoided. Introduction the principal culprit in flow induced vibration of tubes of sthe is the unsupported tube lengths subjected to large flow rates on shell side. Vibration in heat exchangers is one of the main problems that the industry has faced over last few decades. This study evaluates vortex shedding and potential vibration across dead leg branches. The sound is so strong that it can be heard in the area of 10 to 15 m circle. Bachelor of engineering mechanical engineering a computer software was developed for the mechanical design of shellandtube heat exchangers with flowinduced vibration checks based on tubular exchanger manufacturing association inc. Mechanical design of shellandtube heat exchangers with. The program uses a rigorous structural analysis approach to calculate the tubes natural frequencies for fundamental and higher modes and can properly handle any tube support arrangement. Failure analysis of shell and tube heat exchangers raj kulsange mis no121524006 under guidance of. A heat exchanger is a system used to transfer heat between two or more fluids.
This type of heat exchanger has often been used in the lpg gas carrier ship and has sometimes caused a fretting and finally comes to a fatigue failure. Flow induced vibration in shell and tube heat excahnger. Cross flow inducedvibrations in h eat exchanger tube bundles. Jan 21, 2017 vibration in heat exchangers is one of the main problems that the industry has faced over last few decades. The effects of the shellside fluid flow velocity and the. Flow induced vibration problem in a cross flow tube bundle. In contrast buffeting due to flow turbulence causes very little vibration. Vibration phenomenon in heat exchangers is of major concern for designers and process engineers since it can lead to the tube damage, tube leakage, baffle damage, tube collision damage, fatigue, creep etc. I am confront with a flow induced vibration problem in a cross flow tube bundle heat exchanger. Another concern in shell and tube designs is flow induced vibration of the tube bundle. Flow induced tube vibration in shellandtube heat exchangers has resulted in tube failure that has caused industrial plants and power stations to be shut down for costly repairs. It is rare in the hvac industry that we provide a heat exchanger with velocities near the maximum, because the pressure drop gets so high that the engineer doesnt want the added.
Flow induced vibration in a heat exchanger with seal. Pdf on mar 21, 2012, shahab khushnood and others published crossflowinducedvibrations in heat exchanger tube bundles. Flowinduced vibration problems stress engineering services. Flowinduced tube vibration data banks for shellandtube. Aeroacoustic response of the two side byside cylinders with td 1. The main failure mechanisms are generated by the shellside fluid. Airair including is a brief explanation of the problem and history with some illustrations. Heat exchangers are used in both cooling and heating processes. Pdf vibration analysis of shell and tube heat exchanger.
In this paper, the clip is adopted as the countermeasure and it is clarified that the clip. Design optimization of shell and tube heat exchanger by. A recent text that treats heat exchanger vibration analysis extensively,is auyang,m. Flow induced vibration in shell and tube heat excahnger posted in process heat transfer. College of engineering pune introduction of heat exchangers 3.
Pugh, ihs esdu january 1, 2012 mechanical integrity is an essential consideration in heat exchanger design. Phenomenon of vortex induced vibration in heat exchanger, cross flow of the fluid in the shell and the tube are observed. However, the significance of flow induced vibration on heat exchanger reliability did not attract sufficient attention until tube failures became commonplace, particularly in the power industry. Although various design alternatives can be used to avoid vibration problems, they all exact a penalty in. Moretti, flow induced vibrations and flow instabilities, chapter 42 in modern vibrations primer, crc press, boca raton, fl 33431, 2000, isbn 0849320380. Flowinduced vibration in heat exchangers sciencedirect. However, the significance of flow induced vibration on heat exchanger reliability did not attract sufficient attention until tube failures became commonplace, particularly in the. Vibration of tubes in heat exchangers is an important limiting factor in heat exchanger operation. Flowinduced vibration of circular cylindrical structures. It is indeed true that sporadic failure of tubes in operating heat exchangers occurred even before the 60s. I think you would have to get acceleration measurements directly on the tubes or at least the tubesheets supporting the tube ends. Research paper vibration analysis of aes type shell. Stv4 flowinduced acoustic vibration in tube bundles htri.
The flow induced vibration of pipes due to internal flowing fluid is studied and investigated. Cross flow induced vibration due to shell side fluid flow ar ound the tubes bundle of shell and tube heat exchanger results in tube vibration. Equations were developed to express the influence of internal fluid flow on the natural frequency and displacement amplitude of vibrating pipes. When the flow in a heat exchanger s secondary side interacts with the array of tubes containing the primary fluid, tube vibration inevitably occurs. Pdf on mar 21, 2012, shahab khushnood and others published crossflow inducedvibrations in heat exchanger tube bundles. The study includes, but not limited to, turbulence induced vibration, vorticity shedding induced vibration, and the fluid elasticstability. The increased size of sthe due to large flow rates is.
In flow induced vibration, there are vortex induced vibration, fluid elastic instability and buffeting. The weak coupling method and the fluid solid interface are used to solve the fluidstructure interaction problem with consideration of the geometry and physical natures. Cross flow induced vibration due to shell side fluid flow around the tubes bundle of shell and tube heat exchanger results in tube vibration. Specific design limitations are described in light of the current understanding of flow induced vibration phenomena. Tests were performed as a part of a systematic study of water flow induced vibration in industrialsize heat exchangers. Flow induced vibration in a heat exchanger with seal strips. Flowinduced vibration in shellandtube heat exchangers. For the constant heat flux boundary condition, experiments are carried out on the heat transfer characteristics of elastic tube bundles augmented by flow.
This paper describes the development work carried out to estimate the flow induced vibrating forces and response of a bank of low finned a. Heat exchanger tube vibration mechanical acoustics. One of the techniques used by designers of shellandtube heat exchangers when they encounter a potential flowinduced vibration problem is to shift from a tube bundle with segmental baffles to one with doublesegmental baffles. The main parameters which affect the flow induced vibration are shown below. If the heat exchanger is used in a pneumatic conveying system, a check valve should be placed between the air lock and the heat exchanger.
However, the significance of flow induced vibration on heat exchanger reliability did not attract sufficient attention until tube failures became commonplace. As a result, possible flow induced tube vibration problems have joined thermal, hydraulic, and mechanical design considerations. Pulsation andor vibration can cause metal fatigue and lead to failure of the heat exchanger. Flowinduced noise in heat exchangers journal article. In these heat exchangers, tubes in a bundle are usually the most. The advantage of twisted type shell and tube heat exchanger over conventional heat exchanger are studied in this paper on the basis of economics, performance.
Research paper vibration analysis of aes type shell and. Prevent flow induced vibration in heat exchangers new technology can be used in existing tube bundles to enable higher flowrates without risk of tube damage wanni, a. Stockmeier, fluid viscosity effects on flowinduced vibrations of tubes in crossflow, proceedings of the institution of mechanical engineers, flow induced vibration, pp. Section 5 explores results of flow induced vibra tion analysis, final investigations and results are presented in section 6 and concluding remark is given in section 7. The heat exchanger was of the externally packed floating head type with seal strips that directed the water flow into the bundle to prevent bypassing of the fluid between the. And what i am looking for are people that may had experience or are familiar with this phenomenon. This works present a new approach to enhance the heat transfer rate by the flow induced vibration, insert coiled into the tube of the heat exchanger and constructed in a real plant. This paper addresses the implications of potential flow induced acoustic and tube vibration problems to the design of a shellandtube heat exchanger. The flow induced vibration analysis of a shell and tube heat exchanger is an integral element of its thermal design. The main failure mechanisms are generated by the shellside fluid that passes around. Halle argonne national laboratory, argonne, illinois, 60439, j. Flow induced noise in heat exchangers is a very complex phenomenon.
Design optimization of sthe by vibration analysis through htri. Pdf crossflowinducedvibrations in heat exchanger tube. Also, since maintenance is necessary, the cost of the entire operation is quite high. Flowinduced vibration fiv analysis vortex shedding. Flowinduced vibration article about flowinduced vibration. Experimental study on crossflow induced vibrations in heat. Flow induced vibration, or vortex shedding, is due to high flow velocities such as in a piping dead leg of a centrifugal compressor system. May 16, 2007 this results in a split of the flow into either half of the shell with lower velocities and makes it possible to reduce the unsupported tube span length while keeping below a given allowable pressure drop. The satisfactory performance of heat exchangers is crucial to the reliability of the plant. The approach involved complex mechanics and geometric analysis to arrive at new and simple equations which compares. This is a major concern of designers, process engineers and. The vibration analysis of sthe helps in achieving optimization in design by prevention of tube failure caused due to flow induced vibration. Theory of flow induced vibration failures of heat exchangers caused by flow induced vibration are mainly in terms of the detriments of heat exchanger tubes.
However, on the negative side, higher velocity on the shell side of the exchanger increases the potential for tube vibration. Heat exchanger tube bundles may fail due to excessive vibration or noise. Ppt on failure analysis of shell and tube heat exchangers. This fluid may be a liquid, gas or multiphase mixture. For instance, the slender bodies of aircraft fuselages, missiles, and rockets, and the main bodies of industrial smokestacks, power transmission cables, telephone wires, oil pipelines, reactor fuel rods, heat exchanger tubes, and offshore structures.
The responses of the flow induced vibration of an elastic tube bundle subjected to the shellside cross flow are investigated in this paper. Flow induced vibration can be a serious problem in shellandtube heat exchangers. Xvib performs flowinduced vibration analysis of a single tube in a heat exchanger bundle. Fluidelastic instability in heat exchanger tube arrays and a galerkin.
The vibration is caused by nonstationary fluid dynamic processes occurring in the flow. The study can also include fiv excitation of smallbore piping and components in the flow, such as thermowells. This will help to prevent clogging the heat exchanger with the product being conveyed. Prevention and cure of flowinduced vibration problems in. Operation problem in heat exchanger failures caused by flow induced vibration leakage from bolted joints structural problems the excessive tube fouling thermal stresses in the internal of the heat exchanger performance problems stress corrosion, galvanic corrosion.
Velocity limits in gasketed plate heat exchangers part 4. Generally, there are several main mechanisms for flow induced vibration in heat exchangers as follows. Most of the heat exchangers used in nuclear, petrochemical and power generation industries. Flow induced vibration analysis of a shell and tube heat exchanger is an integral element of its thermal design. Mechanics of flow induced vibration failures of heat exchangers caused by flow induced vibration are mainly in terms of the detriments of heat exchanger tubes. Viscous flow in pipes, laminar pipe flow characteristics 16 of 34 duration. May 30, 2007 flow induced tube vibration in shellandtube heat exchangers has resulted in tube failure that has caused industrial plants and power stations to be shut down for costly repairs. Although this generalized model, referred to as the quasiunsteady model, can be applied in a vast range of flow induced vibration problems, including classical aeroelasticity, it was primarily developed to improve the theoretical prediction of the fluidelastic behaviour of a single flexible cylinder positioned in the midst of an array of rigid. The main failure mechanisms are generated by the shellside uid that passes around. Hi to all, during designing the shell and tube heat exchanger in aspen edr, flow induced vibration appears as warning. This program was motivated by the high cost of heat exchanger failure, particularly, the oftenaccompanying cost of interrupted production. A procedure for checking a shellandtube heat exchanger for possible acoustic vibration problems is outlined in this report.
The main failure mechanisms are generated by the shellside fluid that passes around and between the tubes. Good heat exchanger design requires that the designer understands and accounts for the vibration mechanisms that might occur, such as vortex shedding, turbulent excitation or fluidelastic instability. The effect of flow induced vibration in heat exchanger can be realized by drastic requirement in power and roaring sound in heat exchanger. Among the topics of flow induced vibration, cylindrical structures play very important and vital roles. Additionally, some energy is expended when pipe vibrations create sound waves in atmosphere external to the pipe. They are widely used in space heating, refrigeration, air conditioning, power stations, chemical plants. Heat exchanger tubes can be damaged or fail if subjected to excessive flow induced vibration, either from fatigue or frettingwear. Most sophisticated thermal design software packages carry out vibration analysis as a routine ingredient of thermal design. The complexities are caused by several factors that affect the noise. Research paper vibration analysis of aes type shell and tube. In the present study, vibration response is analyzed on single tube located in the. Flow induced vibration in shellandtube heat exchangers with doublesegmental baffles h. This is a major concern of designers, process engineers and operators, leading to large.
Flowinduced tonal noise and acoustic resonance problems are found in a variety of applications that range from nuclear power plant heat exchangers to automobile air conditioning evaporators. In this paper a simplified approach to optimize the design of shell tube heat exchanger sthe by flow induced vibration analysis fva is presented. A very serious problem in the mechanical design of heat exchangers is flow induced vibration of the tubes. Numerical analysis of shellside flowinduced vibration of. Vibration analysis of shell and tube heat exchanger for low temperature thermal desalination plant.
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