Du B.,Shandong Electric Power Research Institute |
Wang J.,Huaneng Dezhou Power Plant |
Sun G.,Datang Huangdao Power Generation Co. |
Xu Y.,Datang Huangdao Power Generation Co. |
And 2 more authors.
Jinshu Rechuli/Heat Treatment of Metals | Year: 2012
T91/Inconel601 dissimilar metal weld joint which cracked during long-time and high-temperature service was characterized in terms of microstructure and the reason of failure was also analyzed. The results show that weld joint fails in the mode of brittle cracking caused by creep damage. Relatively high stress level of weld joint is the mechanical factor of cracking, and the presence of carbide-rich zone formed along the fusing line near T91 steel is the metallurgical factor. Due to synergetic effect of carbon diffusion driven by difference of carbon activity and relatively lower carbon atom diffusion speed in the nickel-based weld metal, carbide enriched and precipitated in the zone of T91 steel near the fusing line.
Liu F.,Shandong Electric Power Research Institute |
Xu W.,Datang Huangdao Power Generation Co. |
Hu D.,Datang Huangdao Power Generation Co. |
Xian L.,Datang Huangdao Power Generation Co.
Jixie Gongcheng Xuebao/Journal of Mechanical Engineering | Year: 2013
The developments of coal tangentially fired technology are concisely reviewed and technical details of reducing NOx emissions combined with alleviating the gas temperature deviation are discussed for a newly designed combustion system in pulverized coal boiler. Field tests are carried out to alleviate the steam temperature deviation in the crossover pass of a 660 MW boilers, major attention was paid to the coordination of the rotational momentum required for the residual swirl elimination with the air staged flow necessary for reducing NOx emissions by the changes in yaw angles of separated over-fire air. The effects of nozzle tilt angle for reheater steam temperature regulation, pressure difference of furnace with wind box, flow-rates and yaw angles of over-fire air, are quantitatively investigated on steam temperature deviation in division platen superheaters in the upper furnace, it shows that the gas temperature deviation are eliminated in tangentially fired pulverized coal boiler by field combustion optimization, and keeping low NOx emissions of 449.0 mg/m3 and higher combustion efficiency in the meantime. Suggestions of putting steam temperature deviation into automatic control are proposed in large scale, advanced low NOx, tangentially fired pulverized coal boiler. © 2013 Journal of Mechanical Engineering.