THE CROSSING FREQUENCY AS A MEASURE OF HEAT EXCHANGER SUPPORT-PLATE EFFECTIVENESS

2002 ◽  
Vol 16 (1) ◽  
pp. 83-92 ◽  
Author(s):  
M.K. AU-YANG
Keyword(s):  
Heat Exchanger ◽  
Support Plate

Fretting Wear of Heat Exchanger Tubes—Part II: Models

1979 ◽  
Vol 101 (4) ◽  
pp. 630-633 ◽  
Author(s):  
R. D. Blevins
Keyword(s):  
Experimental Data ◽  
Heat Exchanger ◽  
Relative Motion ◽  
Empirical Models ◽  
Fretting Wear ◽  
Support Plate

Conceptual and empirical models are developed for the fretting wear of heat exchanger tubes. The models based on the experimental data of Part I of this series and on the concept that fretting wear is the result of relative motion between the tube and the support plate.

Fretting Wear of Heat Exchanger Tubes—Part I: Experiments

1979 ◽  
Vol 101 (4) ◽  
pp. 625-629 ◽  
Author(s):  
R. D. Blevins
Keyword(s):  
Heat Exchanger ◽  
Empirical Model ◽  
Room Temperature ◽  
Fretting Wear ◽  
Support Plate ◽  
Air Atmosphere ◽  
The Mean

The results of a series of measurements made on the fretting wear of heat exchanger tubes and support plates at room temperature in a nitrogen/air atmosphere are presented. The fretting wear is shown to be a function of the amplitude and frequency of tube vibration as well as the gap between the tube and the support plate and the mean load supported by the tube. An empirical model is developed in Part II for predicting the fretting wear.

scholarly journals Experimental Study on Impact/Fretting Wear in Heat Exchanger Tubes

1987 ◽  
Vol 109 (3) ◽  
pp. 265-274 ◽  
Author(s):  
J. H. Cha ◽  
M. W. Wambsganss ◽  
J. A. Jendrzejczyk
Keyword(s):  
Heat Exchanger ◽  
Plate Thickness ◽  
Fretting Wear ◽  
304 Stainless Steel ◽  
Plate Interface ◽  
Wear Rates ◽  
Inconel 600 ◽  
Support Plate ◽  
Fluid Environment ◽  
Support Tube

The objective of this study is to provide qualitative impact/fretting wear information for heat exchanger tubes through the performance of a series of tests involving the pertinent parameters: force between the tube and its support; tube to support plate hole clearance; tube support plate thickness; preload; and tube vibration frequency. The characteristics of impact/fretting wear relative to material combinations and fluid environment were also investigated. The test apparatus consists of a cantilevered tube with a simulated tube support plate at the “free end.” Tube vibration is induced by an electromagnetic exciter to simulate the flow-induced tube motion occurring in a real heat exchanger at the tube/tube support plate interface. Tests are conducted in air, water, and oil, all at room temperature. Removable wear rings are attached to the tube free end and simulated support fixture. Wear ring materials include carbon steel, 304 stainless steel, Inconel 600 and brass. Wear is measured by a weight loss technique and wear rates are calculated and reported as functions of the various pertinent parameters. Based on the test results, general conclusions are drawn.

The influence of support plate on MFL testing for a heat exchanger tube

2019 ◽  
Vol 59 (4) ◽  
pp. 1349-1356
Author(s):  
Jianbo Wu ◽  
Hui Xia ◽  
Xiaoming Huang ◽  
Tingjun Wu ◽  
Erlong Li ◽  
...  
Keyword(s):  
Heat Exchanger ◽  
Heat Exchanger Tube ◽  
Support Plate ◽  
Exchanger Tube

scholarly journals Dynamic Characteristics of Heat Exchanger Tubes Vibrating in a Tube Support Plate Inactive Mode

1986 ◽  
Vol 108 (3) ◽  
pp. 256-266 ◽  
Author(s):  
J. A. Jendrzejczyk
Keyword(s):  
Experimental Study ◽  
Heat Exchanger ◽  
Heat Exchangers ◽  
Damping Ratio ◽  
Steam Generators ◽  
Support Plate ◽  
Interaction Dynamics ◽  
Fabrication Tolerances ◽  
Shell And Tube ◽  
Inactive Mode

Tubes in shell-and-tube heat exchangers, including nuclear plant steam generators, derive their support from longitudinally positioned tube support plates (TSPs). Typically, there is a clearance between the tube and TSP hole. Depending on design and fabrication tolerances, the tube may or may not contact all of the TSPs. Non-contact results in an inactive TSP which can lead to detrimental flow-induced tube vibrations under certain conditions dependent on the resulting tube-TSP interaction dynamics and the fluid excitation forces. The purpose of this study is to investigate the tube-TSP interaction dynamics. Results of an experimental study of damping and natural frequency as functions of tube-TSP diametral clearance and TSP thickness are reported. Calculated values of damping ratio and frequency of a tube vibrating within an inactive TSP are also presented together with a comparison of calculated and experimental quantities.

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.

Direct Observation of Heat Exchanger Deposits by Cross Sectioning

1967 ◽  
Vol 25 ◽  
pp. 364-365
Author(s):  
R. W. Anderson ◽  
D. L. Senecal
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Heat Exchanger ◽  
Direct Observation ◽  
Cross Sections ◽  
Preparation Method ◽  
Specimen Preparation ◽  
Flowing Water ◽  
Transmission Electron ◽  
Deposit Layer

A problem was presented to observe the packing densities of deposits of sub-micron corrosion product particles. The deposits were 5-100 mils thick and had formed on the inside surfaces of 3/8 inch diameter Zircaloy-2 heat exchanger tubes. The particles were iron oxides deposited from flowing water and consequently were only weakly bonded. Particular care was required during handling to preserve the original formations of the deposits. The specimen preparation method described below allowed direct observation of cross sections of the deposit layers by transmission electron microscopy.The specimens were short sections of the tubes (about 3 inches long) that were carefully cut from the systems. The insides of the tube sections were first coated with a thin layer of a fluid epoxy resin by dipping. This coating served to impregnate the deposit layer as well as to protect the layer if subsequent handling were required.

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