• 제목/요약/키워드: Gas Turbine Bucket

검색결과 12건 처리시간 0.028초

가스터빈 고온부품의 재생 접합을 위한 손상부 파악 (The Consideration of the Damage in Gas Turbine Hot Parts for Repair Bonding Process)

  • 김성욱;최철;김재철;이창희
    • 동력기계공학회지
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    • 제7권2호
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    • pp.73-79
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    • 2003
  • The present study was aimed at analysing the damage of a used gas turbine bucket after 39,500h of total service. Microstructures and cracks of service-induced bucket were observed. The crack might have initiated from the coating in the bucket surface by thermal fatigue and propagated into the GTD111 base metal. Maximum depth of penetration was 2.7 mm(full penetration) at the leading edge. Crack contains a lot of Cr-,Ti-,Al-oxide which will prohibit filling and wetting of insert metal. Depth and propagation direction of crack were accorded with centrifugal force and temperature distribution in turbine bucket. Present result will provide basic data for repair bonding process.

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1,100℃급 가스터빈 1단 버켓 사용품 및 주조품 품질평가 (Quality Evaluation of the 1st Stage Scraped and Casted Buckets of 1,100℃ Gas Turbine Blade)

  • 장성용;김두수
    • KEPCO Journal on Electric Power and Energy
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    • 제5권2호
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    • pp.93-101
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    • 2019
  • $1,100^{\circ}C$급 가스터빈 1단 버켓 사용품 및 주조품 분석을 위하여 기계적 특성과 미세 구조를 분석하여 최종적으로 상기고온부품의 품질을 평가 하였다. 가스터빈 1단 버켓은 고온부품들 중 1단 노즐을 제외하고 가장 고온 및 고압의 환경에서 노출되어 운전되고 있으며, 또한 1단 버켓은 회전체이므로 손상 시 후단의 버켓 및 노즐에 대해 추가적인 설비 파손을 야기하여 막대한 경제적 손실을 초래할 수 있다. 따라서, 버켓의 국산화를 위한 주조품의 경우 발전소현장에 적용하여 사용하기 이전에 신뢰성이 선 검증되어야만 한다. 본 연구에서는 국내 주조품의 미세조직분석 및 기계적 특성평가를 수행하여 주조품질을 평가하고 전력연구원에서 설계한 품질조건을 만족함을 확인하였으며, 품질 비교를 위해 수명의 46% (11,067EOH)를 운전한 사용품에 대해서도 미세조직분석 및 기계적 특성 평가를 수행하였다.

모델 변천에 따른 가스터빈 1단 버켓의 손상경향 분석 (Analysis of Damage Trend for Gas Turbine 1st Bucket Related to the Change of Models)

  • 김문영;박상열;양성호;최희숙;고원;송국현
    • 대한기계학회논문집A
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    • 제31권6호
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    • pp.718-724
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    • 2007
  • Some of gas turbine model of 7F-Class has constructed and is operating with units domestically. Non-destructive testing (NDT) is one of the methods being used to inspect damage $1^{st}$ stage bucket and review damage trends. We also analyze damage configuration and microstructure according to material and compare with pape of electric power research institute (EPRI). The damaged mode could be determined by leveraging failure analysis. Especially, configuration uprate of bucket is not only to prevent damage during operation but also avoid domestic manufacturing by the competitors. Modifications were mainly concentrated on surfaces such as cooling hole and bucket tips. Analyzing of bucket damage, the earlier model of 7F-Class used with one cycle with equivalent operation hour (EOH), has various cracking of the bucket surface. Bucket damage of new model is centered on tip area (54%) as analyzed by EPRI research. We conclude that improving bucket configuration would increase repair rate on the bucket tip.

7FA/FA+급 1 단 버켓 위한 신정비기법 개발 (New Repair Technologies for 7FA/FA+ Class Stage 1 Buckets)

  • 강신호;정길진;김대은
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2003년도 춘계학술대회
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    • pp.2205-2210
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    • 2003
  • The 1st stage bucket of the 170MW simple cycle gas turbine is one of the components that is normally run in exposed state at the highest thermally stressful environment while the turbine is operating. After certain period operation, various type of damages are easily found and the damages are identified as due to the turbine operating mode of which the demand of the electricity power is very peaking and cyclic. Since this trend is more evident at some part of power plants in Korea and it has caused higher scrap rate of the bucket at the first repair interval than other country. Therefore, demand for the higher capability and alternative technologies which allow salvaging more buckets and preventing from severe damages is always high. In this study, a review and estimation of the repair technologies for the past 5 years to present have been conducted and show results.

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GTD-111DS 가스터빈 블레이드 재질의 열처리에 따른 재질 특성변화 (Properties Variation According to Heat Treatment for Gas Turbine Blade(Bucket) Material of GTD-111DS)

  • 박상열;양성호;김문영
    • 대한기계학회논문집A
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    • 제30권3호
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    • pp.349-355
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    • 2006
  • The gas turbine components is used on high temperature conditions which under severely circumstance with start-up and stop several times. Therefore, it is used nickel-base superalloys like and GTD-111DS. Damaged buckets on the t긴ade tip during operating are repaired per 24,000 hr to three times according to repair specification of manufacture. It is applied pre-heat, HIP(hot isostatic pressing) and post-heat treatment to support welding repair on blade tip effectively. On this study, It is utilize of $WRAP^{TM}$ (welding repair advanced process) method to make tension test specimens for this study, And then, material strength and characteristic for GTD-111DS was analyzed.

열처리조건에 따른 Ni기지 초합금 용접부의 기계적 특성 (Mechanical Properties for Welding Part on Ni Base Superalloy Material According to Heat Treatment Parameters)

  • 양성호;박상열;최희숙;고원;채나현;김문영
    • 대한기계학회논문집A
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    • 제31권4호
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    • pp.525-531
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    • 2007
  • The operating temperature has been increased to improve the efficiency of gas turbine. The most advanced Gas turbine is operated at above $1,500^{\circ}C$. Improvement in material and cooling method permit hot gas path component to run at increased temperature. But, the repair of blades which are developed with advanced manufacture technique is difficult to use normal welding. Most of gas turbine blades are made of precipitation harden nickel base superalloy, which is very hard to weld. Therefore, the employment of welding filler on blade is solid solution nickel base superalloy(Hastelloy X, Inconel 617). In this study, Tensile test in high temperature was conducted on welded GTD111DS with GTD111 to evaluate effect of variation of pre, post treatment. The result of this study showed that the specimen was treated with optimum pre and post treatment(preweld HT($1200^{\circ}C$), Post treatment($1100^{\circ}C$ HIP, $1200^{\circ}C$ + $1100^{\circ}C$ + $800^{\circ}C$ HT) is mush superior.

가스터빈의 코팅층 건정성 평가를 위한 적외선 열화상 카메라 기법 활용 (IR Camera Technique Application for Evaluation of Gas Turbine Blades Covering Integrity)

  • 김재열;양동조;최철준;박상기;안연식;정계조
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2005년도 추계학술대회 논문집
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    • pp.192-196
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    • 2005
  • Key part of main equipment in a gas turbine may be likely to be damaged due to operation under high temperature, high pressure, high-speed rotation, etc. Accordingly, the cost for maintenance increases and the damaged parts may cause generation to stop. The number of parts for maintenance also increases, but diagnostics technology fur the maintenance actually does not catch up with the demand. Blades are made of precipitation hardening Ni superalloy IN738 and the like for keeping hot strength. The surface of a blade is thermal-sprayed, using powder with main compositions such as Ni, Cr, Al, etc. in order to inhibit hot oxidation. Conventional regular maintenance of the coating layer of a blade is made by FPI (Fluorescent Penetrant Inspection) and MTP (Magnetic Particle Testing). Such methods, however, are complicated and take long time and also require much cost. In this study, defect diagnostics were tested for the coating layer of an industrial gas turbine blade, using an infraredthermography camera. Since the infrared thermography method can check a temperature distribution on a wide range of area by means of non-contact, it can advantageously save expenses and time as compared to conventional test methods. For the infrared thermography method, however, thermo-load must be applied onto a tested specimen and it is difficult to quantify the measured data. To solve the problems, this essay includes description about producing a specimen of a gas turbine blade (bucket), applying thermo-load onto the produced specimen, photographing thermography images by an infrared thermography camera, analyzing the thermography images, and pre-testing for analyzing defects on the coating layer of the gas turbine blade.

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