Vibration Analysis of a Cooling Fan Gear Reducer of the Secondary Cooling Tower in HANARO

하나로 2차 냉각탑의 냉각팬 감속기의 진동분석

  • Park, Young-Chul (Dev. of Research Reactor Engineering, Korea Atomic Energy Research Institute)
  • 박용철 (원자력(연) 연구로 공학부)
  • Received : 2010.01.06
  • Accepted : 2010.05.20
  • Published : 2010.07.01


HANARO is an open-tank-in-pool-type Korean research reactor that generates 30MW of thermal power. It differs from power plant reactor in that the heat generated by HANARO is exhausted into the atmosphere through a secondary cooling tower, thus maintaining the core temperature constant. During every monthly inspection of the cooling tower, large vibrations that exceeded the permissible limit were observed at cooling fan gear reducer No. 4 of the cooling tower. The purpose of this study is to identify the origin of the large vibration and to repair it. FFT spectrum analysis is performed to identify the part that caused the large vibration. The results of the frequency analysis showed that the vibration frequency was 354 Hz, which is twice the natural frequency of the pinion gear. A check of the pinion gear revealed that there was a crack on the surface of the pinion gear. After the gear was replaced, the reducer operated normally.


HANARO;Cooling Tower;Gear Reducer;High Vibration Analysis


Supported by : 과학기술부


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