Crossflowinducedvibrations in heat exchanger tube bundles. Cross flow induced vibrations in heat exchanger tube bundles. Vortex induced vibration viv is an important source of fatigue damage of offshore oil exploration and production risers. College of engineering pune introduction of heat exchangers 3. These slender structures experience both current flow and topend vessel motions, which give rise to the flowstructure relative motion and cause viv. Flowinduced vibration article about flowinduced vibration. Noise and vibration analysis of a heat exchanger the. 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. The vibration is caused by nonstationary fluid dynamic processes occurring in the flow.
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. Design and development of shell and tube heat exchanger for. Ppt on failure analysis of shell and tube heat exchangers 1. 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. Vortex shedding when shell side fluid flows across heat exchanger tubes. Shellandtube heat exchangers are commonly used in oil refineries and other large chemical processes. Vibrations introduced by hawki after the modification ccc cooling bars new heat exchanger s.
Flow induced vibration, or vortex shedding, is due to high flow velocities such as in a piping dead leg of a centrifugal compressor system. Heat exchangers are used in both cooling and heating processes. Jan 21, 2017 vibration in heat exchangers is one of the main problems that the industry has faced over last few decades. Sarafraz and hormozi 2 found heat transfer enhancement of 67% at 1. Tube vibration, if left unresolved, may result in catastrophic tube failures and the subsequent unplanned shutdown of the unit. This study evaluates vortex shedding and potential vibration across dead leg branches. Flowinduced vibration of heatexchanger tube bundles often causes serious damage, resulting in reduced effi ciency and high maintenance costs. In flowinduced vibration, there are vortexinduced vibration, fluid elastic instability and buffeting. Bridges golden gate bridge, san francisco 1951 wind speed. A procedure for checking a shellandtube heat exchanger for possible acoustic vibration problems is outlined in this report. Tube failures due to excessive flowinduced vibration must be. This paper presents a mathematical model for cross flow induced vibration of tube.
Different ways of reducing vibrations induced by cryogenic. Experimental study on crossflow induced vibrations in. The heat produced due to fission in the core is transported by primary sodium to the secondary sodium in a sodium to sodium intermediate heat exchanger ihx, which in turn is transferred to water in the steam generator. In a singlephase heat exchanger, both of the fluids cooled and heated remain in their initial gaseous or liquid states. It was not until the 60s, when widespread failure of tubes began to occur 16. 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.
Also, since maintenance is necessary, the cost of the entire operation is quite high. In the present study, vibration response is analyzed on single tube located. Fiorentin, et al noise and vibration analysis of a heat exchanger. 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.
In contrast buffeting due to flow turbulence causes very little vibration. In order to estimate the crack location and depth in the pipe, we need to utilize the variation of the difference between the natural frequencies of the pipe conveying fluid with and. In the present work we attempt to create a new type of tube heat exchanger which can vibrate under the influence of the fluid flow. Vortexinduced vibration viv is an important source of fatigue damage of offshore oil exploration and production risers. Wambsganss argonne national laboratory, argonne, illinois, 60439. Halle argonne national laboratory, argonne, illinois, 60439, j. Pfbr ihx is a shell and tube type heat exchanger with primary sodium on shell side and secondary sodium in the tube side. The original tube heat exchanger was designed in normal characteristic 2 pieces of utube which is immersed. The most probable and widely observed mechanism of piping steadystate vibrations is 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 study can also include fiv excitation of smallbore piping and components in the flow, such as thermowells. 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. Flowinduced vibration in heat exchangers request pdf.
John richard thome ltcm sgm epfl heat transfer heat exchanger design 1er mars 2008 6 41 the cross. If the overall heat transfer coefficient is expected to be 1. Request pdf flowinduced vibration in heat exchangers heat exchanger tube bundles may fail due to excessive vibration or noise. Flow induced noise in heat exchangers is a very complex phenomenon. Pdf crossflowinducedvibrations in heat exchanger tube. Among the topics of flowinduced vibration, cylindrical structures play very important and vital roles. The satisfactory performance of heat exchangers is crucial to the reliability of the plant. Cfd study for cross flow heat exchanger with integral finned.
A practical guide for planning, selecting and designing of shell and tube exchangers takes users on a stepbystep guide to the design of heat exchangers in daily practice, showing how to determine the effective driving temperature difference for heat transfer. Flowinduced vibration in shellandtube heat exchangers. Design optimization of sthe by vibration analysis through htri. Effect of flow arrangement on the heat transfer behaviors. Flow induced vibration in a heat exchanger with seal. These are turbulent pressure pulsations see turbulent flow, vortex initiation and separation from tubes in crossflow see crossflow, hydroelastic.
Cross flow inducedvibrations in h eat exchanger tube bundles. Heat exchanger tube arrays, flow induced vibrations, fluidelastic instability, unsteady reynolds averaged navierstokes turbulence models. Flowinduced vibration fiv analysis vortex shedding. Accelerometer and microphone positions in the heat exchanger. Flowinduced vibration of shell and tube heat exchangers sthes has been known for a long time. Jul 08, 2016 report on failure analysis of shell and tube heat exchangers 1. The fluids may be separated by a solid wall to prevent mixing or they may be in direct contact. Aeroacoustic response of the two side byside cylinders with td 1. Cfd study for cross flow heat exchanger with integral finned tube. In flow induced vibration, there are vortex induced vibration, fluid elastic instability and buffeting. Vibration is usually divided into two character types. Then you can start reading kindle books on your smartphone, tablet, or computer no kindle device required. Generally, there are several main mechanisms for flowinduced vibration in heat exchangers as follows.
In the present study, vibration response is analyzed on single tube located in the. Using the geometric dimensions and the flow conditions associated with this micro heat exchanger, a total heat flux of. Figure 4 shows a vibration measurement recorded right after the modification. Introduction ashley and haviland, 1950 1 studied the flow induced vibration of the trans. Fluidelastic instability in heat exchanger tube arrays and a galerkin.
Flow induced vibration in shellandtube heat exchangers with doublesegmental baffles h. Heat transfer 1 heat exchangers heat transfer heat exchanger types of heat exchangers heat exchangers are classified according to flow arrangement and type of construction. Guidelines for acoustic induced vibration aiv, flow induced. Among the topics of flow induced vibration, cylindrical structures play very important and vital roles. Lesson30 numerical problems related to heat exchanger. Vibration analysis is conducted to prevent pipe damage during the design. But the other problems are caused after analysis of vibration. High velocity steam cross flow over condenser tube bundles excite the tubes significantly, causing all types of flow induced vibration mechanisms. Improving tube design of a problematic heat exchanger for. 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. Flowinduced vibration of circular cylindrical structures. 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, heatexchanger tubes, and offshore structures, as well as. The topend vessel motion causes the riser to oscillate and the.
The water temperatures at the inlet of test tube were 50, 60, 70, 80 c. Then you can start reading kindle books on your smartphone, tablet, or computer. Ppt on failure analysis of shell and tube heat exchangers. Cross flow induced vibration of heat exchanger tube banks by s.
Experimental study on crossflow induced vibrations in heat. Design and development of shell and tube heat exchanger. 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. Mechanics of flowinduced vibration failures of heat exchangers caused by flowinduced vibration are mainly in terms of the detriments of heat exchanger tubes. Cfd, cross flow, heat exchanger, integral fin, heat transfer coefficient. Doublepipe heat exchanger one fluid flows through the smaller pipe while the other fluid flows through the annular space between the two pipes. Clearly, such extreme causes of vibration must always be avoided. Trans icheme, vol 80, part a, april 2002 flowinduced 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. Vibration of tubes in heat exchangers is an important limiting factor in heat exchanger operation. Flowinduced vibration, or vortex shedding, is due to high flow velocities such as in a piping dead leg of a centrifugal compressor system.
Heat transfer enhancement by flowinduced vibration in heat. Only two important relationships constitute the entire thermal design. Request pdf heat transfer enhancement by flowinduced vibration in heat exchangers a b s t r a c t the flowinduced vibration in heat exchanger is usually considered as a detrimental factor. Temperature control by heat exchanger incorporating with. Effectiveness and overall heat transfer coefficient o water. The main parameters which affect the flow induced vibration are shown below. Besides, for this microchannel heat exchanger, the heat transfer and fluid effect of flow arrangement on the heat transfer behaviors. 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. Flowinduced vibrations of heat exchanger tube bundles often cause serious. Experience with vibration at a ductmounted heat exchanger, inst.
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. Cross flow inducedvibrations in heat exchanger tube bundles. Vibration mitigation heat exchanger solutions condenser. Thus, the flow induced vibration represents a major operational and design constraint. For example, a particular type of flow induced vibration called fluidelastic instability places an upper limit on the flow velocity, and hence heat exchange rates and hence electricity generating capacity of the entire plant. The vibrationinduced tube rupture could lead to vapor leak in the flash state, and. Flowinduced vibration in heat exchangers sciencedirect. An ordinary heat exchanger is singlephase or twophase. In this model, two separated fluids at different temperatures flow through the heat exchanger, one through the tubes tube side and the other through the shell around the tubes shell side. Request pdf flow induced vibration in heat exchangers heat exchanger tube bundles may fail due to excessive vibration or noise. Introduction ashley and haviland, 1950 1 studied the flowinduced vibration of the trans.
According to the literature, many incidents of failure due to apparent. Heat transfer heat exchanger types of heat exchangers. Vibration signal analysis of the heat exchanger for defects. The main failure mechanisms are generated by the shellside fluid.
Heat exchanger is the equipment which is used to reduce temperature of one process fluid, which is desired to cool, by transferring heat to another fluid which is desired to heat with or without intermixing the fluid or changing the physical state of the fluid. Heat exchanger tubes tend to vibrate under the inuence of. Fluidinduced vibration in heat exchanger tube bundles. Design optimization of shell and tube heat exchanger by. Jul 08, 2016 ppt on failure analysis of shell and tube heat exchangers 1. Fluidinduced vibration within the heat exchangerchinese.
The results showe that the temperature difference and heat transfer coefficient for heat exchanger with finned tube is higher than with smooth tube. Heat exchanger tubes can be damaged or fail if subjected to excessive flow induced vibration, either from fatigue or frettingwear. Assessment of flow induced vibration in a sodiumsodium heat. Stv4 flowinduced acoustic vibration in tube bundles htri. The cracks occur on pipe wall and heat exchanger is damaged. Heat exchanger tubes can be damaged or fail if subjected to excessive flowinduced vibration, either from fatigue or frettingwear. In twophase exchangers, either of the fluids may change its phase during the heat exchange process.
Heat exchanger thermalhydraulic design procedures top in involve exchanger rating quantitative heat transfer and pressure drop evaluationandor exchanger sizing. This paper describes an approach for practical evaluation and elimination of steadystate vibration. Enter your mobile number or email address below and well send you a link to download the free kindle app. Vibration in heat exchangers is one of the main problems that the industry has faced over last few decades. High velocity steam crossflow over condenser tube bundles excite the tubes significantly, causing all types of flowinduced vibration mechanisms. Shahab khushnood, zaffar muhammad khan, muhammad afzaal malik, zafarullah koreshi, muhammad akram javaid, mahmood anwer khan, arshad hussain qureshi, luqman ahmad nizam, khawaja sajid. Introduction over the past few decades, the utility industry has suffered enormous financial losses because of vibration related problems in stea m generators and heat exchangers. 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. Xvib performs flowinduced vibration analysis of a single tube in a heat exchanger bundle. Flowinduced vibration of shell and tube heat exchangers heat. Flowinduced vibration analysis of supported pipes with a crack. Flowinduced vibration problems stress engineering services. These slender structures experience both current flow and topend vessel motions, which give rise to the flow structure relative motion and cause viv.
Two of the simplest and most important problems are referred to as the rating and sizing problems. A heat exchanger tube bundle showing some window and interior tubes. Excessive flow induced vibrations may cause tube failures by fretting. The result is excellent and the hawki vibration contribution computed using the equation 1 has been reduced to some. 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. A few heat exchangers have vibration problems caused by velocity of flow, piping vibration and karman vortex. The complexities are caused by several factors that affect the noise. In this paper, the clip is adopted as the countermeasure and it is clarified that the clip.