Analytical and Experimental Flow-Induced Vibration Analysis of a Shell and Tube Cooling Water Heat Exchanger

2002 ◽  
Author(s):  
Alberto F. Marti´n Ghiselli ◽  
Rau´l M. Kulichevsky ◽  
Mauricio A. Sacchi ◽  
Alberto J. Pastorini ◽  
Ce´sar G. Belinco
Keyword(s):  
Heat Exchanger ◽  
Cooling Water ◽  
Fretting Wear ◽  
Design Stage ◽  
Dynamical Response ◽  
Original Design ◽  
Flow Induced Vibration ◽  
Design Modification ◽  
Operational Conditions ◽  
Shell And Tube

A flow-induced vibration problem evaluation of a shell and tube cooling water heat exchanger equipment installed in a power plant is presented in this paper. The problem produced loss of thickness in many tubes of the bundle, by impact or fretting wear, and the need to plug these tubes to avoid leakage. These vibrations could had been produced by changes in the equipment operational conditions or by a wrong evaluation during the design stage. An analytical and experimental evaluation was made to predict tubes dynamical response and to identify the excitation mechanisms. The original design modification adopted to solve the problem is presented and evaluated.

A Probabilistic Assessment Technique Applied to a Cracked Heat Exchanger Tube Subjected to Flow-Induced Vibration

2009 ◽  
Vol 131 (3) ◽  
Author(s):  
Brady T. Vincent ◽  
Marwan A. Hassan ◽  
Robert J. Rogers
Keyword(s):  
Heat Exchanger ◽  
Service Life ◽  
Threshold Value ◽  
Fretting Wear ◽  
Heat Exchanger Tube ◽  
Flow Induced Vibration ◽  
Remaining Service Life ◽  
Elastic Forces ◽  
Shell And Tube ◽  
Exchanger Tube

Flow-induced vibration is a common phenomenon in shell-and-tube heat exchangers. The resulting vibration can lead to component failure by fretting wear due to tube-to-tube support impact or by fatigue. Due to manufacturing considerations, many parameters such as support clearance, alignment, and friction at the supports are not exactly known and are represented by statistical distributions. This makes the use of deterministic equations inaccurate. This paper presents a methodology that can be used during component operation to monitor known flaws and ensure safe operation. The methodology incorporates Monte Carlo simulations to predict remaining service life of a vibrating heat exchanger tube with a small circumferential through-wall crack next to the tube sheet. Vibration excitation includes turbulence and low-level fluid-elastic forces. Leakage calculations are made on the through-wall crack as it grows to fracture. A Weibull distribution is given for the time-to-fracture and for the time for the leak rate to reach a threshold value. This statistical information can then be used to assess the remaining service life and whether LBB criteria will be met.

Numerical Study of Flow Induced Vibration of the Tube Bundle in a Lash Baffle Shell-and-Tube Heat Exchanger

2013 ◽  
Author(s):  
Haiyang Sun ◽  
Caifu Qian
Keyword(s):  
Heat Exchanger ◽  
Numerical Study ◽  
Tube Bundle ◽  
Lateral Displacement ◽  
Small Hole ◽  
Flow Induced Vibration ◽  
Tube Heat Exchanger ◽  
New Type ◽  
Shell And Tube ◽  
Jet Characteristics

In this paper, flow induced vibration of the tube bundle in a shell-and-tube heat exchanger with a new type of baffle, namely large-and-small-hole or LASH baffle, is studied numerically and compared with that in a segmental baffle shell-and-tube heat exchanger. It is found that as a parallel flow with jet characteristics between the large holes and tubes conducted by the LASH baffles, the fluid-induced vibration of tube bundle in the LASH baffle heat exchanger can be prevented and the lateral displacement variation is greatly decreased.

scholarly journals CFD evaluation of the influence of the parts of a shell and tube heat exchanger on heat transfer

2021 ◽  
Vol 345 ◽  
pp. 00007
Author(s):  
Jiří Frank ◽  
Michal Volf ◽  
Stefan Bajić
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Cooling Water ◽  
Temperature Fields ◽  
Tube Heat Exchanger ◽  
Flow And Heat Transfer ◽  
Design Changes ◽  
Exhaust Fumes ◽  
Shell And Tube ◽  
Effective Use

This article deals with numerical fluid flow and heat transfer simulations of a shell and tube heat exchanger in which cooling water is heated by hot exhaust fumes. This heat exchanger plays a major role in a cogeneration unit, since it is responsible for the effective use of residual heat. The objective of the simulations is to evaluate the effects of various design changes made to the heat exchanger and their influence on the temperature fields and thus on the overall performance and efficiency of the system. In our analysis we looked at the baffles which cause the cross-current flow of water outside the tubes and at the placement of the gas inlet, i.e., on the distribution of the mass flow rate of the exhaust fumes inside these tubes.

Flow Induced Vibration in a Heat Exchanger With Seal Strips

1982 ◽  
Vol 104 (2) ◽  
pp. 372-378
Author(s):  
J. H. Kissel
Keyword(s):  
Heat Exchanger ◽  
Velocity Profile ◽  
Natural Frequency ◽  
Water Flow ◽  
Critical Section ◽  
Shell Side ◽  
Flow Induced Vibration ◽  
Shell And Tube ◽  
Vibration Tests ◽  
Head Type

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. The heat exchanger was of the externally packed floating head type with seal strips that directed the water flow into the bundle to prevent by-passing of the fluid between the bundle and the shell. High localized velocities exist in the vicinity of the seal strips and contributed directly to the vibration problem. The tube natural frequency for various baffle spacings was measured at the vibration point and a gap velocity at the critical section of the bundle was estimated. A correlation was then made with these parameters and the fluidelastic excitation theory. A discussion of the velocity profile through the heat exchanger is included.

scholarly journals Heat Exchanger Sizing for Organic Rankine Cycle

Energies ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3615 ◽  
Author(s):  
James Bull ◽  
James M. Buick ◽  
Jovana Radulovic
Keyword(s):  
Heat Exchanger ◽  
Power Systems ◽  
Waste Heat ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Operating Conditions ◽  
Working Fluid ◽  
Two Phase ◽  
Operational Conditions ◽  
Shell And Tube

Approximately 45% of power generated by conventional power systems is wasted due to power conversion process limitations. Waste heat recovery can be achieved in an Organic Rankine Cycle (ORC) by converting low temperature waste heat into useful energy, at relatively low-pressure operating conditions. The ORC system considered in this study utilises R-1234yf as the working fluid; the work output and thermal efficiency were evaluated for several operational pressures. Plate and shell and tube heat exchangers were analysed for the three sections: preheater, evaporator and superheater for the hot side; and precooler and condenser for the cold side. Each heat exchanger section was sized using the appropriate correlation equations for single-phase and two-phase fluid models. The overall heat exchanger size was evaluated for optimal operational conditions. It was found that the plate heat exchanger out-performed the shell and tube in regard to the overall heat transfer coefficient and area.

Evaluation of Spar In-Field Performances for Topsides Payload Increase and Operational Changes

2015 ◽  
Author(s):  
Aldric Baquet ◽  
Joe Zhou ◽  
Lixin Xu ◽  
Yong Chen
Keyword(s):  
Hurricane Katrina ◽  
Weight Change ◽  
Operating Conditions ◽  
Design Stage ◽  
Design Criteria ◽  
Accurate Information ◽  
Original Design ◽  
Operational Conditions ◽  
Overall Design ◽  
Operating Limits

In the initial design stage of an offshore platform, some conservative assumptions might be used for the platform hull and Topsides weights, wind area and Metocean criteria of environments. After the platform is installed, actual results from weight surveys and real-time snapshots of the as-built operating platform typically provide more accurate information for the purpose of assessing real operational conditions and future changes of these conditions. For example, in field operations, it is particularly useful to quantify how much weight can be added to the as-built operating facility, while assuring that the platform still meets the overall design criteria and regulatory requirements. This paper presents an effective method for evaluation of an in-field operating Spar platform, to determine the maximum allowable envelops for topsides weight change verse the topsides VCG, based on the Spar global performances and riser operating limits. The case study is performed for a Spar in the Gulf of Mexico (GOM), based on the Spar as-built data and actual in-field configurations of hull/mooring and risers, and using the updated Metocean criteria (after the Hurricane Katrina in the GOM). The analysis results of the allowable topsides weight change and topsides VCG limits, accounting for the Spar in operating, extreme and survival conditions, are based on three governing factors: (1) the Spar motions meet the original design criteria for global performances, and are within the safety range of riser operations; (2) the maximum loads at critical connections between the Spar hard tank and the topsides structures are within the design loads; and (3) the reserve variable ballast is sufficient to balance the Spar at an even keel position at the design draft for all required operating conditions.

Vibration Damping in Multispan Heat Exchanger Tubes

1998 ◽  
Vol 120 (3) ◽  
pp. 283-289 ◽  
Author(s):  
C. E. Taylor ◽  
M. J. Pettigrew ◽  
T. J. Dickinson ◽  
I. G. Currie ◽  
P. Vidalou
Keyword(s):  
Heat Exchanger ◽  
Fretting Wear ◽  
Resonant Peak ◽  
Effect Of Temperature ◽  
Squeeze Film ◽  
Fluid Viscosity ◽  
Viscous Damping ◽  
Friction Damping ◽  
Flow Induced Vibration ◽  
Squeeze Film Damping

Heat exchanger tubes can be damaged or fail if subjected to excessive flow-induced vibration, either from fatigue or fretting-wear. 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. To incorporate these phenomena into a flow-induced vibration analysis of a heat exchanger requires information about damping. Damping in multispan heat exchanger tubes largely consists of three components: viscous damping along the tube, and friction and squeeze-film damping at the supports. Unlike viscous damping, squeeze-film damping and friction damping are poorly understood and difficult to measure. In addition, the effect of temperature-dependent fluid viscosity on tube damping has not been verified. To investigate these problems, a single vertical heat exchanger tube with multiple spans was excited by random vibration. Tests were conducted in air and in water at three different temperatures (25, 60, and 90°C). At room temperature, tests were carried out at five different preloads. Frequency response spectra and resonant peak-fitted damping ratios were calculated for all tests. Energy dissipation rates at the supports and the rate of excitation energy input were also measured. Results indicate that damping does not change over the range of temperatures tested and friction damping is very dependent on preload.

Non-Linear Time Domain Method to Predict Tube-to-Tube Support Plate Fretting Wear in Steam Generators

2006 ◽  
Author(s):  
J. A. Burgess ◽  
M. K. Au-Yang ◽  
C. K. Chandler
Keyword(s):  
Heat Exchanger ◽  
Time Domain ◽  
Time History ◽  
Fretting Wear ◽  
Design Stage ◽  
Superposition Method ◽  
Linear Interaction ◽  
Support Plate ◽  
Forcing Function ◽  
Non Linear

Fretting-wear of nuclear heat exchanger equipment is addressed at the design stage to demonstrate that the tube and tube support plate components will meet their design life. AREVA has developed a method to predict the progression of fretting-wear using a combination of the predicted work-rates determined from the non-linear interaction of the tube and tube support plates caused by turbulence-induced vibration and the forces associated with fluid-elastic instability. The wear rate is then computed based upon the work-rate and the experimentally determined wear coefficient of the material pair. This solution is performed with a time domain analysis using a time history modal superposition method. Time history forcing functions are first obtained by the inverse Fourier transform of the power spectral density function used in classical turbulence-induced vibration analysis. The fluid-structure coupling force, which is dependent on the cross-flow velocity, is linearly superimposed onto the turbulence forcing function. The tube responses are then computed by direct integration in the time domain. The results of the analysis show that the highest work-rates occur at the design tube-to-tube support plate clearance configuration and become progressively lower over the life of the heat exchanger. The work-rates and the turbulence-induced vibration response of the tube are computed at several mid-life time steps based upon the increased tube-to-tube support plate clearances resulting from the tube wear.

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