Wear Studies of Materials for Tubes and Antivibration Bars in Nuclear Steam Generators

1996 ◽  
Vol 118 (3) ◽  
pp. 287-300 ◽  
Author(s):  
P. L. Ko ◽  
M.-C. Taponat ◽  
M. Zbinden
Keyword(s):  
Relative Motion ◽  
Nuclear Power ◽  
Room Temperature ◽  
High Flow ◽  
Steam Generators ◽  
Wear Model ◽  
Flow Rates ◽  
Wear Rates ◽  
Inconel 600 ◽  
Wear Damage

Wear occurs as a result of relative motion at the interface of two contacting bodies. In nuclear power steam generators, high flow rates can induce vibration of the tubes resulting in wear damage due to impact and sliding contacts between the tubes and their supports. A research project aiming to gain better understanding of the mechanisms and mechanics involved in vibratory wear and to develop a more versatile predictive wear model was carried out. Combinations of Inconel tubes against flat antivibration bars of 403 SS and electrolytic-chrome plated Inconel 600 were tested under conditions of reciprocating sliding and impacting in water at room temperature and at 250°C. The results show that, depending on the material combinations and he loading conditions, distinctively different wear mechanisms and often drastically different wear rates can occur.

scholarly journals Influence of flow rate, fluid temperature, and extension line on Hotline and S-line heating capability: an in vitro study

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Hosu Kim ◽  
Tae Kyong Kim ◽  
Sukha Yoo ◽  
Jin-Tae Kim
Keyword(s):  
Flow Rate ◽  
Room Temperature ◽  
In Vitro Study ◽  
High Flow ◽  
High Flow Rate ◽  
Low Flow ◽  
Fluid Temperature ◽  
Flow Rates ◽  
Fluid Warmer

Abstract Background A fluid warmer can prevent hypothermia during the perioperative period. This study evaluated the heating capabilities of Hotline and Barkey S-line under different flow rates and initial fluid temperatures, as well as after the extension line installation. Methods We measured the temperature of a 0.9% sodium chloride solution at the fluid warmer outlet (TProx) and the extension line end (TDistal) with three different initial fluid temperatures (room, warm, and cold) and two flow rates (250 ml/hr and 100 mL/hr). Results At a 250 ml/hr flow rate, the TProx and TDistal values were observed to be higher in Hotline than in S-line when using room-temperature or cold fluid. Administering of the warm fluid at the same flow rate significantly increased the TProx and TDistal values in S-line more than the cold and room-temperature fluids. At flow rates of 100 ml/hr, TDistal values were significantly lower than TProx values in both devices regardless of the initial fluid temperature. Conclusions Hotline outperformed S-line for warming fluids at a high flow rate with cold or room-temperature fluids. Administering warm fluid in S-line prevented a decrease in the fluid temperature at a high flow rate. However, at a low flow rate, the fluid temperature significantly decreased in both devices after passing through an extension line.

Experimental Studies of Tube Frettings in Steam Generators and Heat Exchangers

1979 ◽  
Vol 101 (2) ◽  
pp. 125-133 ◽  
Author(s):  
P. L. Ko
Keyword(s):  
Heat Exchangers ◽  
Power Plants ◽  
Room Temperature ◽  
Operating Temperature ◽  
Experimental Studies ◽  
Steam Generators ◽  
Standard Equipment ◽  
Flow Rates ◽  
Support Interaction ◽  
Design Life

High flow rates in steam generators and heat exchangers may create flow-induced tube vibrations which cause local wear through impacting and rubbing on tube supports and/or with adjacent tubes. The steam generators in CANDU power plants have a design life of 30 yr; it is, therefore, essential that design criteria be developed to minimize tube fretting and to establish acceptable limits of vibration. Standard equipment has been developed to study the effect on tube fretting due to various parameters, such as tube/tube-support interaction, materials combinations, and support geometry. Tests have been conducted in water and steam at boiler operating temperature (265°C) and at room temperature.

A Review of Wear Scar Patterns of Nuclear Power Plant Components

2003 ◽  
Author(s):  
Pak L. Ko ◽  
Agne`s Lina ◽  
Antoine Ambard
Keyword(s):  
Heat Exchangers ◽  
Nuclear Power ◽  
Steam Generators ◽  
Flow Induced Vibration ◽  
Dynamic Interactions ◽  
Mechanical Wear ◽  
Special Cases ◽  
Erosion Corrosion ◽  
Wear Damage ◽  
Almost All

To date, almost all the studies related to component damage have been concerned primarily with dynamic interactions at the interface of contacting components and the subsequent damage due to mechanical wear. Based on the results of examination of a large assortment of photo-micrographs taken from worn reactor components and worn specimens from a broad range of test facilities, it appears that, in many cases, mechanical wear is only a secondary contributing mechanism. With the exception of special cases where severe flow-induced vibration might have occurred, such as in some condensers and primary heat exchangers as well as in the U-bend and inlet regions of some earlier steam generators, resulting in severe component interactions causing substantial wear damage, erosion, corrosion, impacting and perhaps cavitation would seem to be the primary contributing mechanisms.

Fluidelastic Instability Modeling of Loosely Supported Multispan U-Tubes in Nuclear Steam Generators

2012 ◽  
Vol 135 (1) ◽  
Author(s):  
Marwan Hassan ◽  
Atef Mohany
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Complex Dynamics ◽  
Tube Bundle ◽  
Design Guidelines ◽  
Fretting Wear ◽  
Contact Ratio ◽  
Steam Generators ◽  
Fluidelastic Instability ◽  
Wear Damage

Steam generators in nuclear power plants have experienced tube failures caused by flow-induced vibrations. Two excitation mechanisms are responsible for such failures; random turbulence excitation and fluidelastic instability. The random turbulence excitation mechanism results in long-term failures due to fretting-wear damage at the tube supports, while fluidelastic instability results in short-term failures due to excessive vibration of the tubes. Such failures may require shutdowns, which result in production losses, and pose potential threats to human safety and the environment. Therefore, it is imperative to predict the nonlinear tube response and the associated fretting-wear damage to tubes due to fluid excitation. In this paper, a numerical model is developed to predict the nonlinear dynamic response of a steam generator with multispan U-tubes and anti-vibration bar supports, and the associated fretting wear due to fluid excitation. Both the crossflow turbulence and fluidelastic instability forces are considered in this model. The finite element method is utilized to model the vibrations and impact dynamics. The tube bundle geometry is similar to the geometry used in CANDU steam generators. Eight sets of flat-bar supports are considered. Moreover, the effect of clearances between the tubes and their supports, and axial offset between the supports are investigated. The results are presented and comparisons are made for the parameters influencing the fretting-wear damage, such as contact ratio, impact forces, and normal work rate. It is clear that tubes in loose flat-bar supports have complex dynamics due to a combination of geometry, tube-to-support clearance, offset, and misalignment. However, the results of the numerical simulation along with the developed model provide new insight into the flow-induced vibration mechanism and fretting wear of multispan U-tubes that can be incorporated into future design guidelines for steam generators and large heat exchangers.

PWR Steam Generator Tube and AVB Wear Under Perpendicular Impacting

2013 ◽  
Author(s):  
Christian Phalippou ◽  
Franck Ruffet ◽  
Emmanuel Herms ◽  
François Balestreri
Keyword(s):  
Steam Generator ◽  
Nuclear Power ◽  
Power Plants ◽  
Published Data ◽  
Steam Generators ◽  
Dynamic Interactions ◽  
Pressurized Water ◽  
Steam Generator Tube ◽  
Wear Rates ◽  
Alloy 690

Flow-induced vibrations of steam generator tubes in nuclear power plants may result in wear damage at support locations. The steam generators in EPR power plants have a design life of 60 years; as wear is an identified ageing damage in steam generators, it is therefore important to collect experimental results on wear of tube and support due to dynamic interactions at EPR secondary side temperature. In this study, wear tests were performed between a steam generator tube (Alloy 690) and two flat opposite anti-vibration bars (AVB in 410s stainless steel) at different impact force levels. Tests were performed in pressurized water at 290°C in wear machines for long term repeated predominant impact motions. The worn surfaces were observed by SEM, the wear coefficients of tube and AVB were evaluated using the work rate approach. Significant scoring, due to the importance of sliding when impacts occur, was shown on wear scar patterns. There were greater wear volumes and depths on tubes than on AVBs, but dynamic forced conditions and rigid mounting of AVB in the rigs have prevailed for finally getting an upper bound of the wear rates. Alloy 690 for tubes and 410s for AVB remain a satisfactory material combination considering comparative wear results with other published data.

scholarly journals Influence of flow rate, fluid temperature, and extension line on Hotline and S-line heating capability: an in vitro study

2020 ◽  
Author(s):  
Hosu Kim ◽  
Tae Kyong Kim ◽  
Sukha Yoo ◽  
Jin-Tae Kim
Keyword(s):  
Flow Rate ◽  
Room Temperature ◽  
In Vitro Study ◽  
High Flow ◽  
High Flow Rate ◽  
Low Flow ◽  
Fluid Temperature ◽  
Flow Rates ◽  
Fluid Warmer

Abstract Background A fluid warmer can prevent hypothermia during the perioperative period. This study evaluated the heating capabilities of Hotline and Barkey S-line under different flow rates and initial fluid temperatures, as well as after the extension line installation. Methods We measured the temperature of a 0.9% sodium chloride solution at the fluid warmer outlet (TProx) and the extension line end (TDistal) with three different initial fluid temperatures (room, warm, and cold) and two flow rates (250 ml/hr and 100 mL/hr). Results At a 250 ml/hr flow rate, the TProx and TDistal values were observed to be higher in Hotline than in S-line when using room-temperature or cold fluid. Administering of the warm fluid at the same flow rate significantly increased the TProx and TDistal values in S-line more than the cold and room-temperature fluids. At flow rates of 100 ml/hr, TDistal values were significantly lower than TProx values in both devices regardless of the initial fluid temperature. Conclusions Hotline outperformed S-line for warming fluids at a high flow rate with cold or room-temperature fluids. Administering warm fluid in S-line prevented a decrease in the fluid temperature at a high flow rate. However, at a low flow rate, the fluid temperature significantly decreased in both devices after passing through an extension line.

scholarly journals Influence of flow rate, fluid temperature, and extension line on Hotline and S-line heating capability: an in vitro study

2020 ◽  
Author(s):  
Hosu Kim ◽  
Tae Kyong Kim ◽  
Sukha Yoo ◽  
Jin-Tae Kim
Keyword(s):  
Flow Rate ◽  
Room Temperature ◽  
In Vitro Study ◽  
High Flow ◽  
High Flow Rate ◽  
Low Flow ◽  
Fluid Temperature ◽  
Flow Rates ◽  
Fluid Warmer

Abstract Background A fluid warmer can prevent hypothermia during the perioperative period. This study evaluated the heating capabilities of Hotline and Barkey S-line under different flow rates and initial fluid temperatures, as well as after the extension line installation. Methods We measured the temperature of a 0.9% sodium chloride solution at the fluid warmer outlet (TProx) and the extension line end (TDistal) with three different initial fluid temperatures (room, warm, and cold) and two flow rates (250 ml/hr and 100 mL/hr). Results At a 250 ml/hr flow rate, the TProx and TDistal values were observed to be higher in Hotline than in S-line when using room-temperature or cold fluid. Administering of the warm fluid at the same flow rate significantly increased the TProx and TDistal values in S-line more than the cold and room-temperature fluids. At flow rates of 100 ml/hr, TDistal values were significantly lower than TProx values in both devices regardless of the initial fluid temperature. Conclusions Hotline outperformed S-line for warming fluids at a high flow rate with cold or room-temperature fluids. Administering warm fluid in S-line prevented a decrease in the fluid temperature at a high flow rate. However, at a low flow rate, the fluid temperature significantly decreased in both devices after passing through an extension line.

scholarly journals Influence of Flow Rate, Fluid Temperature, and Extension Line on Hotline and S-Line Heating Capability: an in Vitro Study

2020 ◽  
Author(s):  
Hosu Kim ◽  
Tae Kyong Kim ◽  
Sukha Yoo ◽  
Jin-Tae Kim
Keyword(s):  
Flow Rate ◽  
Room Temperature ◽  
In Vitro Study ◽  
High Flow ◽  
High Flow Rate ◽  
Low Flow ◽  
Fluid Temperature ◽  
Flow Rates ◽  
Fluid Warmer

Abstract Background A fluid warmer can prevent hypothermia during the perioperative period. This study evaluated the heating capabilities of Hotline and Barkey S-line under different flow rates and initial fluid temperatures, as well as after the extension line installation. Methods We measured the temperature of a 0.9% sodium chloride solution at the fluid warmer outlet (TProx) and the extension line end (TDistal) with three different initial fluid temperatures (room, warm, and cold) and two flow rates (250 ml/hr and 100 mL/hr). Results At a 250 ml/hr flow rate, the TProx and TDistal values were observed to be higher in Hotline than in S-line when using a room-temperature fluid; similar results were observed for the cold fluid. Administration of the warm fluid was observed to significantly increase the TProx and TDistal values in S-line at rates of 250 ml/hr more than the administration of the cold and room-temperature fluids. At flow rates of 100 ml/hr, TDistal values were significantly lower than TProx values in both devices regardless of the initial fluid temperature. Conclusions Hotline outperformed S-line for warming fluids at a high flow rate with cold or room-temperature fluids. The administration of the initially warm fluid prevented a decrease in the fluid temperature at a high flow rate in S-line. However, at a low flow rate, the fluid temperature significantly decreased in both devices after passing through an extension line.

The Effects of Ion Implantation on the Surface Features of Inconel 600

1985 ◽  
Vol 43 ◽  
pp. 288-289
Author(s):  
John D. Rubio
Keyword(s):  
Grain Boundary ◽  
Ion Implantation ◽  
Nuclear Power ◽  
Power Plants ◽  
Surface Region ◽  
Selective Dissolution ◽  
Boundary Region ◽  
Near Surface ◽  
Inconel 600 ◽  
Steam Generator Tubing

The degradation of steam generator tubing at nuclear power plants has become an important problem for the electric utilities generating nuclear power. The material used for the tubing, Inconel 600, has been found to be succeptible to intergranular attack (IGA). IGA is the selective dissolution of material along its grain boundaries. The author believes that the sensitivity of Inconel 600 to IGA can be minimized by homogenizing the near-surface region using ion implantation. The collisions between the implanted ions and the atoms in the grain boundary region would displace the atoms and thus effectively smear the grain boundary.To determine the validity of this hypothesis, an Inconel 600 sample was implanted with 100kV N2+ ions to a dose of 1x1016 ions/cm2 and electrolytically etched in a 5% Nital solution at 5V for 20 seconds. The etched sample was then examined using a JEOL JSM25S scanning electron microscope.

Monitoring Effects of Catchment Management Practices on Phosphorus Loads into the Eutrophic Peel-Harvey Estuary, Western Australia

1986 ◽  
Vol 18 (4-5) ◽  
pp. 53-61 ◽  
Author(s):  
P. B. Birch ◽  
G. G. Forbes ◽  
N. J. Schofield
Keyword(s):  
Management Practices ◽  
Major Change ◽  
High Flow ◽  
Catchment Management ◽  
Flow Rates ◽  
Early Results ◽  
Phosphorus Loads ◽  
Time Of Year ◽  
High Runoff

Early results from monitoring runoff suggest that the programme to reduce application of superphosphate to farmlands in surrounding catchments has been successful in reducing input of phosphorus to the eutrophic Peel-Harvey estuary. In the estuary this phosphorus fertilizes algae which grow in abundance and accumulate and pollute once clean beaches. The success of the programme has been judged from application of an empirical statistical model, which was derived from 6 years of data from the Harvey Estuary catchment prior to a major change in fertilizer practices in 1984. The model relates concentration of phosphorus with rate of flow and time of year. High phosphorus concentrations were associated with high flow rates and with flows early in the high runoff season (May-July). The model predicted that the distribution of flows in 1984 should have resulted in a flow-weighted concentration of phosphorus near the long-term average; the observed concentration was 25% below the long-term average. This means that the amount of phosphorus discharged into the Harvey Estuary could have been about 2 5% less than expected from the volume of runoff which occurred. However several more years of data are required to confirm this trend.

Sign in / Sign up

Export Citation Format

Share Document