核电站主给水文丘里流量计磨损和破损影响的数值研究

Numerical Study on the Wear and Tear of Venturi Flowmeter in the Main Feedwater of Nuclear Power Plant

针对某核电站主给水文丘里流量计受高温高速的蒸发器给水冲刷产生的磨损和破损问题,通过建立三维模型,应用计算流体力学方法,对其磨损和破损进行定量计算和分析。结果表明:文丘里流量计上下游的缩放区磨损厚度为1 mm时,测得的流量将比实际值偏大不超过0.1%;磨损量为3 mm时,偏大最大达到了0.32%。当文丘里流量计喉部发生磨损,磨损厚度为1 mm时,各流量平台下,测得的流量将比实际值偏小接近2%;随着磨损量的增大,偏差进一步增大,磨损量为3 mm时,流量测量偏小最大达到了6.16%。当文丘里流量计喉部发生破损,汇入缝隙为1 mm时,测得的流量比真实值偏大10%左右;当汇入缝隙扩大到2 mm时,偏大增大到20%。主给水文丘里流量计喉部的磨损和破损对计量的影响较大,将影响蒸发器的水位控制,应该在制造和运行阶段予以重视。

Aiming at the wear and tear of the main feed water Venturi flowmeter of a nuclear power plant,which is eroded by the high temperature and high speed evaporator feed water,the wear and tear are quantitatively calculated and analyzed by establishing a three-dimensional model and applying the computational fluid dynamics method.The results show that:when the wear thickness of the upstream and downstream scaling areas of the Venturi flowmeter is 1 mm,the measured flow rate will be larger than the actual value by no more than 0.1%;when the wear amount is 3 mm,the maximum increase is 0.32%.When the throat of the Venturi flowmeter is worn and the wear thickness is 1 mm,the measured flow rate will be smaller than the actual value by nearly 2%under each flow platform;as the wear amount increases,the deviation further increases,and the wear amount when it is 3 mm,the flow measurement is too small and the maximum is 6.16%.When the throat of the Venturi flowmeter is damaged and the inlet gap is 1 mm,the measured flow rate is about 10%larger than the actual value;when the inlet gap is enlarged to 2 mm,the excess increases to 20%.The wear and tear of the throat of the main feed water Venturi flowmeter has a great impact on the measurement,which will affect the water level control of the evaporator,which should be paid attention to in the manufacturing and operation stages.