Experience of high chromium ferritic steel tubes in power plant

Yukitoshi, Teruo; Yoshikawa, Kunihiko; Daikoku, Takashi; Masuyama, Fujimitsu

doi:10.1007/bf02898277

Cited by 8 publications

(6 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The chemical composition of the steel tubes is provided in Table . The addition of Cr, Mo, and Mn in steel reduces oxide scale growth, , improving overall corrosion resistance, while Ni acts as a deterrent for Cl induced corrosion . Preoxidation of steel tubes is beneficial for hindering corrosion , and provides superior replication of operational boiler tubes. , Thermogravimetric analysis of the steel tubes at 600 °C revealed that the majority of the oxidation occurs in the first few hours, after which the rate of oxidation significantly slows down (see Figure ).…”

Section: Methodsmentioning

confidence: 99%

Deposit Shedding in Biomass-Fired Boilers: Shear Adhesion Strength Measurements

Laxminarayan

Jensen

et al. 2017

Energy Fuels

View full text Add to dashboard Cite

Ash deposition on boiler surfaces is a major problem encountered during biomass combustion. Ash deposition adversely influences the boiler efficiency, may corrode heat transfer surfaces, and may even completely block flue gas channels in severe cases, causing expensive unscheduled boiler shutdowns. Therefore, timely removal of ash deposits is essential for optimal boiler operation. In order to improve the understanding of deposit shedding in boilers, this study investigates the shear adhesion strength of biomass ash deposits on superheater tubes. Artificial biomass ash deposits were prepared on superheater tubes and sintered in an oven at temperatures up to 1000 °C. Subsequently, the deposits were sheared off by an electrically controlled arm, and the corresponding adhesion strength was measured. The results reveal the effect of temperature, deposit composition, sintering duration, and steel type on the adhesion strength.

show abstract

Section: Methodsmentioning

confidence: 99%

Deposit Shedding in Biomass-Fired Boilers: Shear Adhesion Strength Measurements

Laxminarayan

Jensen

et al. 2017

Energy Fuels

View full text Add to dashboard Cite

show abstract

“…TP347HFG is characterized by its high Cr, Mn, and Ni contents. The presence of Cr and Mn in steel reduces oxide scale growth by forming Cr–Mn spinels, , improving the overall corrosion resistance, while Ni deters Cl-induced corrosion …”

Section: Methodsmentioning

confidence: 99%

“…18 TP347HFG is characterized by its high Cr, Mn, and Ni contents. The presence of Cr and Mn in steel reduces oxide scale growth by forming Cr−Mn spinels, 28,29 improving the overall corrosion resistance, 30 while Ni deters Cl-induced corrosion. 31 Apart from hindering corrosion, preoxidation of steel tubes provides a more accurate replication of operational boiler tubes.…”

Section: ■ Experimental Sectionmentioning

confidence: 99%

Tensile Adhesion Strength of Biomass Ash Deposits: Effect of the Temperature Gradient and Ash Chemistry

et al. 2018

View full text Add to dashboard Cite

Replacing coal with biomass in power plants is a viable option for reducing net CO2 emissions and combating climate change. However, biomass combustion in boilers may exacerbate problems related to ash deposition and corrosion, demanding effective deposit removal.The tensile adhesion strength of model biomass ash deposits, containing mixtures of KCl, K2SO4, CaO, CaSO4, and K2Si4O9, has been investigated in this study. The deposits were prepared on 2 superheater steel tubes, and sintered in an oven. The superheater steel tube was cooled by air, incorporating a temperature gradient across the deposits. After sintering, the deposits were removed using an electrically controlled arm, and the corresponding tensile adhesion strength was measured. The effects of flue gas temperature (500 -700 °C), steel surface temperature (500 -650 °C) and deposit composition were investigated. The results revealed that increasing the flue gas temperature, as well as the steel surface temperature, led to a sharp increase in the tensile adhesion strength of the model deposits. The sharp increase was typically observed near the melting temperature (or deformation temperature) of the investigated model deposits. Furthermore, migration of molten/vapor species from the outer layer of the deposit to the deposit-tube interface, causing liquid state sintering, was observed at high flue gas temperatures, leading to an increase in the tensile adhesion strength. Varying the ash chemistry of the model deposits revealed that the melt fraction of the deposit was highly influential in determining the deposit adhesion strength.Addition of compounds which increased the melt fraction of the deposit increased the tensile adhesion strength, whereas addition of inert compounds with a high melting point, such as CaO, decreased the tensile adhesion strength. Moreover, the results suggested that the adhesion strength of the deposits was influenced by the corrosion occurring at the deposit-tube interface.

show abstract

“…This caused a rise in generating costs which resulted in the steam pressure and temperature being lowered again in most plants to 24 MPa and 538°C.…”

Section: Progressive Increases In Steam Pressure Andmentioning

confidence: 99%

“…The 9-12% Cr steels developed most recently have strengths between those of 2.25%Cr-1%Mo steels and 18%Cr-8%Ni steels, or strength equal to or higher than strength of the 18%Cr-8%Ni steels. 9Cr2Mo 24) is a low carbon 9%Cr-2%Mo steel has 28 years of service experience in utility plants and about 2 000 tons of service experience as superheater and reheater tubes and piping since development. The creep rupture strength is between those of 2.25Cr1Mo steels and TP304H, and the material is used especially for reheater tubes as a substitute for 18%Cr-8%Ni steels.…”

Section: Historical Development Of Heat Resistant Steelsmentioning

confidence: 99%