Failure analysis of a boiler tube in USC coal power plant

Lee, Nam-Hyuck; Kim, Sin; Choe, Byung-Hak; Yoon, Kee Bong; Kwon, Dongil

doi:10.1016/j.engfailanal.2008.12.006

Cited by 64 publications

(12 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The exfoliation of the oxide scale from the HT9 steel was probably due to the growth stress taking place when the oxide formed and grew on the specimens and the thermal stress due to the temperature variation caused by the difference in the thermal expansion coefficient between the oxides and the substrate. 25 If the oxide layer spalls at the interface between the inner and outer layers (Figures 8a to 8c), the oxidation rate of the HT9 steel and the thickening rate of the oxide layer after exfoliation do not change substantially. The formation and growth of the oxide layer is still controlled by the diffusion of Fe and O through the inner layer.…”

Section: Discussionmentioning

confidence: 97%

Oxidation behavior of HT9 steel in 700 °C – 900 °C steam

Zhang¹,

Chen²,

Zhao³

et al. 2019

Mater. Tehnol.

View full text Add to dashboard Cite

Oxidation behavior of the HT9 steel exposed to 700°C-900°C steam was investigated with gravimetry, X-ray diffraction and scanning electron microscopy. It was found that the oxidation kinetics of the HT9 steel followed the parabolic law. The mass gain increased with a decreasing temperature. The steam oxidation of the HT9 steel at 800°C and 900°C was selective. The oxides formed on the HT9-steel surface displayed a double-layer structure, consisting of an outer columnar Fe2O3 layer and an inner (Fe, Cr)3O4 layer.

show abstract

Section: Discussionmentioning

confidence: 97%

Oxidation behavior of HT9 steel in 700 °C – 900 °C steam

Zhang¹,

Chen²,

Zhao³

et al. 2019

Mater. Tehnol.

View full text Add to dashboard Cite

show abstract

“…New boiler management systems are equipped with many interlocks to keep the furnace in purged conditions under any unsteady state. Tube side failures are mostly attributed to corrosion or brittleness caused by operational mishandling or manufacturing . Disturbed water chemistry has also been reported to trigger such incidents because of scaling which causes localized overheating .…”

Section: Introductionmentioning

confidence: 99%

Comprehensive dynamic modeling, simulation, and validation for an industrial boiler incident investigation

Taimoor

Alghamdi

Farooqi

et al. 2019

Process Safety Progress

View full text Add to dashboard Cite

Industrial boilers simulation can serve number of purposes like training, optimization, HAZOP studies, and incident investigation. Simulation including trip logics, interlockings, safety devices, start‐up and shutdown procedure is presented in this work. Simulation is directly accomplished in dynamic mode to benefit from the holdup approach to avoid anomalies because of recycling. The industrial DCS/PLC diagrams are replicated to imitate the boiler‐integrated behavior. Trip logics, start‐up and shutdown procedures are programmed using event scheduler. The inbuilt pressure relief module validates the simulated PSVs and rupture disc capacities. The model is then verified at three stages including ‘steady state’ achievement in dynamic mode, controller validation by start‐up and shut down procedures and finally by direct industrial data under deviant conditions. Where an unfortunate event is a concern, it also provides an opportunity to ponder and to evolve at various levels. Operational simulation of any such incident may help in getting a deep insight and thus to take accurate countermeasures. One such attempt is done in this work. A boiler accident has been reported. The complete response of the controllers and interlockings/trip system is imitated. The obtained results were compared with the chain of events that took place. © 2019 American Institute of Chemical Engineers Process Saf Prog: e12040 2019

show abstract

“…They investigated the effect of coating the superheater tubes. In addition, Lee et al [16] conducted a failure analysis on boiler tubes in USC coal power plants. They found that creep ruptures can be caused by softened structures.…”

Section: Introductionmentioning

confidence: 99%

Thermal Characteristics of Tube Bundles in Ultra-Supercritical Boilers

et al. 2016

View full text Add to dashboard Cite

Abstract:In this study, flow and thermal characteristics of tube bundles in ultra-supercritical boilers were analyzed. The local heat transfer around the tube bundles was measured to predict the local temperature distribution and vulnerable positions of the superheated tube bundles. The maximally superheated tube bundles were simulated in the laboratory and local heat transfer was measured by using the naphthalene sublimation method. The experiment was conducted on three lines of tube bundles, all with in-line arrangements. Each line consist of six tubes. The distance in the streamwise direction (S x /∅) was 1.99 and that in the spanwise direction (S z /∅) was 5.45. The Reynolds number varied from 5000 to 30,000, which covers a range of different operating conditions. Thermal and stress analyses were conducted numerically, based on the experimental data. The results showed that the flow characteristic changes the local heat transfer of the tube bundles. The flow impinged on the stagnation point of Tube 1 and reattached at 60 • of Tube 2. The high heat transfer occurred at those positions of the tube bundles. The temperature and stress distributions on the surface of each tube bundle also varied. The reattachment point on Tube 2 had the highest heat transfer and temperature distribution. That position on Tube 2 was subjected to the highest stress due to the large temperature gradient. This result indicates that Tube 2 of the ultra-supercritical (USC) boiler is the weakest of the tube bundles, changing the pitch of the streamwise direction of Tube 2 is one method to reduce the highest stress in superheater tube bundles in the USC boiler.

show abstract

Failure analysis of a boiler tube in USC coal power plant

Cited by 64 publications

References 7 publications

Oxidation behavior of HT9 steel in 700 °C – 900 °C steam

Oxidation behavior of HT9 steel in 700 °C – 900 °C steam

Comprehensive dynamic modeling, simulation, and validation for an industrial boiler incident investigation

Thermal Characteristics of Tube Bundles in Ultra-Supercritical Boilers

Contact Info

Product

Resources

About