蒸汽发生器U形传热管动态特性影响因素分析

Analysis of Factors Influencing Dynamic Characteristics of Steam Generator U-Tubes

采用理论和数值模拟方法对多种工况和影响因素下蒸汽发生器U形传热管的固有频率、模态振型进行了数值模拟。给出了U形管在管内外压力作用和质量随空间位置非均匀分布下的固有频率计算公式。数值模拟结果表明:支撑边界约束处理模式、传热管工作压力、支撑板厚度、防振条支撑点数以及U形弯头曲率半径对U形传热管动态特性影响较大,压力和质量分布的非均匀性、自重及热膨胀等因素影响较弱。

Based on the synthesis of all sorts of factors influencing the dynamic characteristics of steam generator （SG） U-tubes, the natural frequencies, corresponding mode shapes of the U-tubes are analyzed un- der practical load cases and environment by theoretical analysis and numerical simulation. The formulae of calculating the natural frequencies of U-tube considering the effects of internal and external pressures, as well as non-uniform distributed mass density in U-tubes are deduced. Study results reveal that the boundary constraints, pressures in primary and secondary sides, supporting width, support plate number and elbow tube factor bring a strong effect on the dynamic characteristics of U-tubes, and the non-uniformities of pressures and mass along the whole tube, tube deadweight and the heat expansion have little.