Study and Prevention of Steam Flow Induced Vibration of Nuclear Power Plant Condenser

In view of a number of titanium tube cracking events caused by steam flow induced vibration of a certain type of nuclear power condenser under half-side condenser operation conditions, this paper uses the computational fluid dynamics (CFD) method based on porous medium model to conduct a full three-dimensional numerical simulation of the steam-side flow field in the throat and tube bundle area of the condenser and calculates and obtains the steam-side velocity field of the condenser under half-side condenser operation conditions and the steam flow induced vibration risk coefficient distribution of titanium tubes. The simulation calculation results show that the steam flow induced vibration risk of the surface titanium tube in the finger gap area above the air-cooling area of the heat exchange module close to the vertical centerline of the condenser is relatively high under half-condenser operation conditions, and it is necessary to consider installing anti-vibration bars or taking preventive tube plugging measures to reduce the steam flow induced vibration risk. According to the numerical simulation calculation results under the leakage conditons of the condenser during half-side condenser operation and the actual operation records of the nuclear power unit, it is suggested that the electric power limits for the safe operation of the nuclear power plant condenser under the half-condenser operation conditions in summer and winter should be 900 MW and 600 MW respectively. Since the span of the condenser is a bit too large, the span of titanium tube should be shortened to less than 610.5 mm so as to avoid steam flow induced vibration.