KEPCO Journal on Electric Power and Energy

Korea Electric Power Corporation (한국전력공사)
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Simulation of Remote Field Scanner for Defect Evaluation of Water Wall Tube Within the Fluidized Bed Boiler

유동층보일러 수냉벽튜브 결함평가를 위한 원격자장 스캐너 시뮬레이션에 관한 연구

  • Gil, Doo-Song (Power Generation Lab., KEPCO Research Institute, Korea Electric Power Corporation) ;
  • Jung, Gye-Jo (Power Generation Lab., KEPCO Research Institute, Korea Electric Power Corporation) ;
  • Seo, Jung-Seok (Power Generation Lab., KEPCO Research Institute, Korea Electric Power Corporation) ;
  • Kim, Hak-Joon (Department of Mechanical Engineering, Sungkyunkwan University) ;
  • Kwon, Chan-Wool (Department of Mechanical Engineering, Sungkyunkwan University)
  • Received : 2020.01.20
  • Accepted : 2020.03.04
  • Published : 2020.06.30
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Abstract

Water wall tube is one of the major factors consisting of a fluidized bed boiler and it plays very important role for the generation of electricity within the boiler. But these water wall tubes within the fluidized bed boiler are subject to the ware and corrosion caused by the high temperature gas and the flowing medium. If water leak is occurred, the secondary damage by the water leak will occur. As a result of that, the power generation efficiency decreases noticeably. Therefore, the maintenance of the water wall tube is very important. In this study, we designed a exciter sensor based on simulation and composed a remote field eddy current system for the defect evaluation of the outer water wall tube. Starting from the shape design of exciter, we conducted simulations for various design factors such as the water wall tube size, material, frequency, lift-off and so on. Based on the results, we designed the optimum exciter sensor for the water wall tube test within the fluidized bed boiler.

유동층보일러를 구성하는 요소 중 하나인 수냉벽튜브는 외부의 고온 연소 가스를 이용해 물을 증기로 가열하는 튜브군의 하나로써, 보일러를 이용한 전력생산에 중요한 역할을 담당하지만, 고온 가스 및 유동매체로 인해 마모 및 부식이 심하게 일어나면 누수가 발생하게 되고, 누수로 인한 2차 피해도 발생될 뿐만 아니라, 발전 효율이 현저히 떨어지게 되어 수냉벽튜브의 유지보수는 매우 중요하다. 본 연구에서는 원격장 기반의 발신자(Exciter) 센서 설계, 원격장 와전류 시스템 구성, 수냉벽튜브 외벽 결함평가를 목적으로 하였으며, 이를 위한 발신자 형상의 센서 설계를 시작으로, 수냉벽튜브의 크기, 재질, 주파수, Lift-Off (센서와 수냉벽튜브 사이의 거리) 등 여러 가지 요인에 따른 시험을 진행하여 그에 따른 최적의 발신자 센서를 설계하였다.

Keywords

References

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