Ppt on failure analysis of shell and tube heat exchangers. Flow induced vibration, or vortex shedding, is due to high flow velocities such as in a piping dead leg of a centrifugal compressor system. High velocity steam cross flow over condenser tube bundles excite the tubes significantly, causing all types of flow induced vibration mechanisms. Our high performance standards continue beyond the fac. Design and development of shell and tube heat exchanger for. Different ways of reducing vibrations induced by cryogenic instruments j. Heat exchanger tubes can be damaged or fail if subjected to excessive flow induced vibration, either from fatigue or frettingwear. Heat transfer enhancement by flowinduced vibration in. Accelerometer and microphone positions in the heat exchanger. Flowinduced vibration problems stress engineering services. The satisfactory performance of heat exchangers is crucial to the reliability of the plant.
Introduction ashley and haviland, 1950 1 studied the flowinduced vibration of the trans. In the present study, vibration response is analyzed on single tube located. In flowinduced vibration, there are vortexinduced vibration, fluid elastic instability and buffeting. A heat exchanger is constructed with the new designed heat transfer devices. Vibration of tubes in heat exchangers is an important limiting factor in heat exchanger operation. Different ways of reducing vibrations induced by cryogenic. 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. Moretti, why can the prediction of heatexchanger vibrations fail. A heat exchanger is a system used to transfer heat between two or more fluids. 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. College of engineering pune introduction of heat exchangers 3. Reason for heat exchangers a heat exchanger is a piece of equipment built for efficient heat transfer from one medium to.
This study evaluates vortex shedding and potential vibration across dead leg branches. Among the topics of flow induced vibration, cylindrical structures play very important and vital roles. The fluids may be separated by a solid wall to prevent mixing or they may be in direct contact. Flowinduced vibration in heat exchangers sciencedirect. The effect of flow induced vibration in heat exchanger can be realized by drastic requirement in power and roaring sound in heat exchanger.
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. Flow induced noise in heat exchangers is a very complex phenomenon. Heat exchanger tube bundles may fail due to excessive vibration or noise. The main parameters which affect the flow induced vibration are shown below. The complexities are caused by several factors that affect the noise. Pdf on mar 21, 2012, shahab khushnood and others published crossflow inducedvibrations in heat exchanger tube bundles. Temperature control by heat exchanger incorporating with. Among the topics of flowinduced vibration, cylindrical structures play very important and vital roles. Thus the flowinduced vibration is effectively utilized instead of strictly avoiding it in the heat exchanger design. In this paper, the clip is adopted as the countermeasure and it is clarified that the clip. Xvib performs flowinduced vibration analysis of a single tube in a heat exchanger bundle. A plate heat exchanger, phe, is a compact heat exchanger where thin corrugated plates some 0.
Flowinduced vibration of heatexchanger tube bundles often causes serious damage, resulting in reduced effi ciency and high maintenance costs. A heat exchanger is a device in which energy is transferred from one fluid to another across a solid surface. Vortex induced vibration viv is an important source of fatigue damage of offshore oil exploration and production risers. 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. This paper presents a mathematical model for cross flow induced vibration of tube. Experimental study on crossflow induced vibrations in heat. Vibration mitigation heat exchanger solutions condenser. Introduction ashley and haviland, 1950 1 studied the flow induced vibration of the trans. Lesson30 numerical problems related to heat exchanger. In an exchanger with singlesegmental baffles, the total flow, except for leakages and bypasses through necessary clearance spaces, is forced through every.
In many cases, lighthills theory can, nevertheless, be applied successfully, and it is the most commonlyused model for the study of flowinduced sound and vibration. 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. 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. Moretti, flow induced vibrations and flow instabilities, chapter 42 in modern vibrations primer, crc press, boca raton, fl 33431, 2000, isbn 0849320380. Excessive flow induced vibrations may cause tube failures by fretting. Jul 08, 2016 ppt on failure analysis of shell and tube heat exchangers 1. 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. 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. A few heat exchangers have vibration problems caused by velocity of flow, piping vibration and karman vortex.
Much effort has been devoted to the study of the influence of the shellside flow on the vibration of the heat transfer devices. Fluidinduced vibration in heat exchanger tube bundles. This paper describes an approach for practical evaluation and elimination of steadystate vibration. The es extended surface heat exchanger is designed as a compressor intercooler with the ability to cool large volumes of air with. Shellandtube heat exchangers are commonly used in oil refineries and other large chemical processes.
Flowinduced vibration in shellandtube heat exchangers with. Pdf crossflowinducedvibrations in heat exchanger tube. Crossflowinducedvibrations in heat exchanger tube bundles. If the overall heat transfer coefficient is expected to be 1. The result is excellent and the hawki vibration contribution computed using the equation 1 has been reduced to some. Vibration is usually divided into two character types. Vibration signal analysis of the heat exchanger for. Heat exchanger tubes can be damaged or fail if subjected to excessive flowinduced vibration, either from fatigue or frettingwear. The most probable and widely observed mechanism of piping steadystate vibrations is flowinduced vibration. 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.
Shahab khushnood, zaffar muhammad khan, muhammad afzaal malik, zafarullah koreshi, muhammad akram javaid, mahmood anwer khan, arshad hussain qureshi, luqman ahmad nizam, khawaja sajid. Standard design the plate heat exchanger consists of a pack of corrugated metal plates with portholes for the passage of. Vortexinduced vibration viv is an important source of fatigue damage of offshore oil exploration and production risers. Cfd study for cross flow heat exchanger with integral finned tube. Experimental study on crossflow induced vibrations in. Guidelines for acoustic induced vibration aiv, flow induced. In heat exchangers, especially shellandtube heat exchangers, the flow induced vibration can damage the heat transfer devices and tubes, and generate noise. These slender structures experience both current flow and topend vessel motions, which give rise to the flow structure relative motion and cause viv. The water temperatures at the inlet of test tube were 50, 60, 70, 80 c.
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. Design and analysis of a dynamic structure for the study of multiphase flow induced vibration hydrodynamic mass phenomena for countergravity twophase cross. A procedure for checking a shellandtube heat exchanger for possible acoustic vibration problems is outlined in this report. Design and development of shell and tube heat exchanger. In flow induced vibration, there are vortex induced vibration, fluid elastic instability and buffeting. The cracks occur on pipe wall and heat exchanger is damaged. Cross flow induced vibrations in heat exchanger tube bundles. Flowinduced vibration fiv analysis vortex shedding.
High velocity steam crossflow over condenser tube bundles excite the tubes significantly, causing all types of flowinduced vibration mechanisms. 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. Flow induced vibration problems in process and power plants page 4 legend square triangle rotated triangle mean suggested unstable m2. Failure analysis of shell and tube heat exchangers raj kulsange mis no121524006 under guidance of. It was not until the 60s, when widespread failure of tubes began to occur 16. The study can also include fiv excitation of smallbore piping and components in the flow, such as thermowells. Vibrations introduced by hawki after the modification ccc cooling bars new heat exchanger s. Vibration analysis is conducted to prevent pipe damage during the design. 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. 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. Fluidelastic stability diagram for tube bundles asme boiler code, 1998 recent projects involving flowinduced vibration in process.
Thus, the flow induced vibration represents a major operational and design constraint. 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 without crack. The main failure mechanisms are generated by the shellside fluid that passes around. Flowinduced vibration, or vortex shedding, is due to high flow velocities such as in a piping dead leg of a centrifugal compressor system. Noise and vibration analysis of a heat exchanger the. Design optimization of sthe by vibration analysis through htri. Alfa laval aq4 alfaqtm ahricertified plate heat exchanger. They are widely used in space heating, refrigeration, air conditioning, power stations, chemical plants, petrochemical plants, petroleum refineries, natural. Fiorentin, et al noise and vibration analysis of a heat exchanger. Cfd study for cross flow heat exchanger with integral. Cross flow induced vibration of heat exchanger tube banks by s.
Cfd, cross flow, heat exchanger, integral fin, heat transfer coefficient. The original tube heat exchanger was designed in normal characteristic 2 pieces of utube which is immersed. These are turbulent pressure pulsations see turbulent flow, vortex initiation and separation from tubes in crossflow see crossflow, hydroelastic. Heat exchangers are used in both cooling and heating processes.
Flowinduced vibration article about flowinduced vibration. These slender structures experience both current flow and topend vessel motions, which give rise to the flowstructure relative motion and cause viv. 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. In this exercise the students will 1 operate a tubeinshell heat exchanger and 2 analyze heat exchanger performance by the lmtd and ntu methods. Experience with vibration at a ductmounted heat exchanger, inst. 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.
However, the significance of flow induced vibration on heat exchanger reliability did. In the present study, vibration response is analyzed on single tube located in the. Mechanics of flowinduced vibration failures of heat exchangers caused by flowinduced vibration are mainly in terms of the detriments of heat exchanger tubes. Request pdf flowinduced vibration in heat exchangers heat exchanger tube bundles may fail due to excessive vibration or noise. Design optimization of shell and tube heat exchanger by. 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 heat exchanger tube bundle showing some window and interior tubes. The main failure mechanisms are generated by the shellside fluid. Stv4 flowinduced acoustic vibration in tube bundles htri. Flowinduced vibration of circular cylindrical structures.
The sound is so strong that it can be heard in the area of 10 to 15 m circle. Jan 21, 2017 vibration in heat exchangers is one of the main problems that the industry has faced over last few decades. 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. In this article a novel approach is proposed to enhance the heat transfer by using the flowinduced vibration of a new designed heat transfer device.
Only two important relationships constitute the entire thermal design. Presume that the exit temperature of water is not to. Flowinduced vibrations in heat exchanger tube bundles. Figure 4 shows a vibration measurement recorded right after the modification. Our high pressure capability goes beyond 11,000 psig and we offer a variety of materials for high and low temperature applications, as well as low noise design options. Standard design the plate heat exchanger consists of a pack of corrugated metal plates with portholes for the passage of the two fluids between which heat transfer will take place. The vibration is caused by nonstationary fluid dynamic processes occurring in the flow. 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.
Flowinduced vibration analysis of supported pipes with a crack. Flowinduced vibration analysis of supported pipes with a. Vibration in heat exchangers is one of the main problems that the industry has faced over last few decades. The results showe that the temperature difference and heat transfer coefficient for heat exchanger with finned tube is higher than with smooth tube. Generally, there are several main mechanisms for flowinduced vibration in heat exchangers as follows.
Heat transfer enhancement by flowinduced vibration in heat. Tube vibration, if left unresolved, may result in catastrophic tube failures and the subsequent unplanned shutdown of the unit. But the other problems are caused after analysis of vibration. Flowinduced vibration in heat exchangers request pdf. Crossflow induced vibration due to shell side fluid flow around the tubes bundle of shell and tube heat exchanger results in tube vibration. The physical mechanisms corresponding to the 3 source types, and examples of when.
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