孔板厚度对核电站给水流量测量精度影响的数值模拟

核电站给水流量测量精确度至关重要,为了研究核电站给水孔板厚度相关加工标准的合理性,针对孔板厚度参数变化对某核电站给水测量孔板流量计流出系数的影响问题,应用计算流体力学软件,对不同结构参数的孔板流量计进行数值模拟.得到孔板流量计的差压、流出系数以及不同模型的流场分布.结果表明:在孔板厚度(E)不发生变化,节流孔厚度(e)从6 mm变化到5 mm,孔板流量计数值模拟流出系数不断减小,变化值分别为1.840％、2.125％,实际测量流量值将偏大相同百分比的数值;当保持孔板节流孔厚度(e)不变时,改变孔板厚度(E)从11 mm变化为11.15 mm,孔板流量计流出系数变小,变化值为1.56％,同样实际测量流量将偏大1.56％.

Effect of Orifice Plate Thickness on Measurement Accuracy of Feedwater Flow Rate in Nuclear Power Plants

Accuracy of nuclear power plant feedwater flow measurement is critical .Aiming at the impact of changes in orifice thickness parameters on the outflow coefficient of orifice valves in a nuclear power plant''s feedwater measurement, computational fluid dynamics software was used to numerically simulate orifice valves with different structural parameters to obtain the differential pressure, outflow coefficient, and different Flow field distribution of the model. The results show that when the orifice plate thickness E does not change, the orifice thickness e changes from 6mm to 5mm, the orifice valve outflow coefficient decreases continuously, the values are 1.840 % and 2.125 %, respectively, and the actual measured flow value will be larger by the same percentage value; When the orifice plate e is kept unchanged, changing E from 11mm to 11.15mm, the orifice valve outflow coefficient becomes smaller, and the variation value is 1.56 %, and the actual measured flow rate will be 1.56 % larger.