• Title/Summary/Keyword: (보일러 과열기 튜브)

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Development of Evaluation Technique of High Temperature Creep Characteristics by Small Punch-Creep Test Method (I) - Boiler Superheater Tube - (SP-Creep 시험에 의한 고온 크리프 특성 평가 기술 개발(I) - 보일러 과열기 튜브 -)

  • Baek, Seung-Se;Na, Seong-Hun;Na, Ui-Gyun;Yu, Hyo-Seon
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.25 no.12
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    • pp.1995-2001
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    • 2001
  • In this study, a small punch creep(SP-Creep) test using miniaturized specimen(10${\times}$10${\times}$0.5mm) is described to develop the new creep test method for high temperature structural materials. The SP-Creep test is applied to 2.25Cr-lMo(STBA24) steel which is widely used as boiler tube material. The test temperatures applied for the creep deformation of miniaturized specimens are between 550∼600$^{\circ}C$. The SP-Creep curves depend definitely on applied load and creep temperature, and show the three stages of creep behavior like in conventional uniaxial tensile creep curves. The load exponent of miniaturized specimen decreases with increasing test temperature, and its behavior is similar to stress exponent behavior of uniaxial creep test. The creep activation energy obtained from the relationship between SP-Creep rate and test temperature decreases as the applied load increases. A predicting equation or SP-Creep rate for 2.25Cr-lMo steel is suggested. and a good agreement between experimental and calculated data has been found.

Effects of Alkali Metals and Chlorine on Corrosion of Super Heater Tube in Biomass Circulating Fluidized Bed Boiler (순환유동층보일러의 과열기 튜브 부식에 알칼리 금속과 염소가 미치는 영향)

  • Back, Seung-Ki;Yoo, Heung-Min;Jang, Ha-Na;Joung, Hyun-Tae;Seo, Yong-Chil
    • Applied Chemistry for Engineering
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    • v.28 no.1
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    • pp.29-34
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    • 2017
  • This study provides the identification of corrosion cause substances in super heater tube from a commercial scale circulating fluidized bed boiler. Electricity is produced by the combustion of biomass mainly wood waste. The biomass, super heater tube, super heater tube ash, and boiler ash were collected and components associated with corrosion were analyzed. A large amount of oxygen-containing material was found due to oxidation. The chlorine content was analyzed as 6.1% and 4.3% in super heater tube ash and boiler ash respectively which were approximately 20 and 14 times higher than those of designed values. Also, alkaline metal contents (K, Na, Ca) were very high in ash samples collected from super heater tube and boiler. The tendency of slagging and fouling was predicted based on X-Ray Fluorescence (XRF) results. Basicity that can lead to slagging was estimated as 3.62 and 2.72 in super heater tube and boiler ash, respectively. Slagging would occur with ash content when considering the designed value as 0.35.

Effect on Thermal Performance of Superheater Module under Part Load Operation in HRSG (배열회수보일러의 부분부하 운전에 따른 유동불균일이 과열기의 성능에 미치는 영향)

  • Chong, Chae-Hon;Song, Jung-Il
    • Journal of Energy Engineering
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    • v.17 no.3
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    • pp.161-166
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    • 2008
  • The purpose of this study is to apprehend the behavior of exhaust gas flow from gas turbine during part load operation in Heat Recovery Steam Generator. As a first step of this work, internal flow characteristics according to HRSG types were examined by CFD analysis. Next step, tube temperature according to gas turbine 53% and 100% load conditions were calculated by results of CFD and those were compared with temperature data gathered from real plant. Finally, thermal performance due to part load operation was calculated to estimate the influence of heat transfer in superheater. In addition, new type of device is suggested to eliminate the uneven temperature distribution of tubes during part load operation.