Analysis of Thermal Stress and Fatigue Induced by Dryout Oscillation in Once Through Steam Generator
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摘要: 为研究蒸干点波动对蒸汽发生器传热管造成的损伤，以Babcock&Wilcox公司设计的直流蒸汽发生器为原型，首先利用一、二次侧耦合传热的方法得到相关热工水力参数，通过对比不同波动频率下蒸干点径向温度分布确定波动频率的影响，利用有限元分析得到传热管应力分布，最后根据S-N曲线对传热管进行疲劳评估，并探讨相关因素的影响。研究结果表明，蒸干点波动频率较低时径向温度分布与稳态相似，接触二次侧的传热管外壁面更容易发生疲劳损坏，虽然交变应力小于限值，但在堆内环境下存在一定运行隐患，温度波动幅值增大会导致传热管寿命明显下降，采用弹性约束有利于缓解蒸干点波动引起的疲劳。本研究为直流蒸汽发生器传热管在蒸干点波动条件下的寿命预测及安全运行提供了参考。Abstract: In order to study the damage of the heat transfer tube caused by dryout oscillation, the once through steam generator designed by Babcock&Wilcox company is taken as a prototype. Firstly, the relevant thermal and hydraulic parameters are obtained by using the method of primary and secondary side coupled heat transfer. By comparing the radial temperature distribution of dryout point at different fluctuation frequencies, the influence of fluctuation frequency was determined, and the stress distribution of heat transfer tubes was obtained by finite element analysis. Finally, the fatigue of heat transfer tubes was evaluated according to S-N curve, and the influence of related factors was discussed. The results show that when the fluctuation frequency of the drying point is low, the radial temperature distribution is similar to the steady state. The outer wall in contact with the secondary side is more prone to fatigue damage, although the alternating stress is less than the limit value, there is a certain operating risk in the reactor environment. The increase of temperature fluctuation frequency will lead to the obvious decrease of the life of heat transfer tubes, and the use of elastic constraint is helpful to alleviate the fatigue caused by the oscillation of steam drying point. This study provides a reference for the life prediction and safe operation of the heat transfer tubes of once-through steam generator under the condition of fluctuating evaporating point.
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Key words:
- Heat transfer tube /
- Dryout oscillation /
- Wall temperature /
- Fatigue analysis
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图 11 不同温度波动幅值下的交变应力分布
Figure 11. Distribution of Alternating Stress under Different Temperature Fluctuation
图 12 不同基础刚度下交变应力分布
Figure 12. Distribution of Alternating Stress under Different Foundation Stiffness
表 1 单元管几何参数
Table 1. Geometric Parameters of Unit Tube
参数名 参数值 管外径/mm 15.875 壁厚/mm 0.864 管节距/mm 22.225 高度/m 9.3 
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表 2 模型类型
Table 2. Model Types
交换形式 力模型 系数模型 动量交换 曳力 Universal 升力 Moraga 壁面润滑力 Hosokawa 湍流耗散力 Lopez-de-Bertodano 能量交换 Ranz-Marshall
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表 3 边界条件
Table 3. Boundary Conditions
计算域 边界 参数名 参数值 一次侧 进口 质量流速/[kg·(m2·s)−1] 2692.52 温度/K 590.85 出口 压力/MPa 15.17 二次侧 进口 质量流速/[kg·(m2·s)−1] 190.19 温度/K 510.95 出口 压力/MPa 6.38 其他边界为对称面
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[1] LIU H T, KAKAC S, MAYINGER F. Characteristics of transition boiling and thermal oscillation in an upflow convective boiling system[J]. Experimental Thermal and Fluid Science, 1994, 8(3): 195-205. doi: 10.1016/0894-1777(94)90048-5 [2] DONG X M, ZHANG Z J, LIU D, et al. Numerical investigation of the effect of grids and turbulence models on critical heat flux in a vertical pipe[J]. Frontiers in Energy Research, 2018, 6: 58. doi: 10.3389/fenrg.2018.00058 [3] DONG X M, DUARTE J P, LIU D, et al. Numerical investigation of azimuthal heat conduction effects on CHF phenomenon in rod bundle channel[J]. Annals of Nuclear Energy, 2018, 121: 203-209. doi: 10.1016/j.anucene.2018.07.033 [4] WANG M J, WANG Y J, TIAN W X, et al. Recent progress of CFD applications in PWR thermal hydraulics study and future directions[J]. Annals of Nuclear Energy, 2021, 150: 107836. doi: 10.1016/j.anucene.2020.107836 [5] ZENG C J, WANG M J, WU G, et al. Numerical study on the enhanced heat transfer characteristics of steam generator with axial economizer[J]. International Journal of Thermal Sciences, 2022, 182: 107794. doi: 10.1016/j.ijthermalsci.2022.107794 [6] HE S P, WANG M J, TIAN W X, et al. Development of an OpenFOAM solver for numerical simulations of shell-and-tube heat exchangers based on porous media model[J]. Applied Thermal Engineering, 2022, 210: 118389. doi: 10.1016/j.applthermaleng.2022.118389 [7] 史建新. 直管式直流蒸汽发生器蒸干及蒸干后传热数值模拟[D]. 哈尔滨: 哈尔滨工程大学, 2019. [8] 肖军,武学素,庄贺庆,等. 快堆蒸汽发生器沸腾传热恶化引起的热应力计算和分析[J]. 核动力工程,1992, 13(3): 63-68. [9] 刘萌萌,张震,杨星团,等. 蒸汽发生器传热管密度波振荡现象研究[J]. 核动力工程,2021, 42(1): 8-14. [10] KWON J S, KIM D H, SHIN S G, et al. Assessment of thermal fatigue induced by dryout front oscillation in printed circuit steam generator[J]. Nuclear Engineering and Technology, 2022, 54(3): 1085-1097. doi: 10.1016/j.net.2021.09.004 [11] 张蕊,田文喜,秋穗正,等. 基于CFD方法的棒束通道内临界热流密度预测[J]. 原子能科学技术,2018, 52(5): 782-787. doi: 10.7538/yzk.2018.52.05.0782 [12] 董晓朦. 棒束通道沸腾传热与两相流动CFD分析及应用[D]. 哈尔滨: 哈尔滨工程大学, 2019. [13] BECKER K M, LING C H, HEDBERG S, et al. Experimental investigation of post dryout heat transfer: KTH-NEL-33.[R]. Stockholm: Royal Institute of Technology, 1983. [14] SINGH S, DHIR V K. Scaling of the thermal oscillations in the tubes of once through steam generators[C]//ASME. HTD (American Society of Mechanical Engineers. Heat Transfer Div. ). New York: American Society of Mechanical Engineers, 1983, 27: 63-73. [15] CHIANG T, FRANCE D M, BUMP T R. Calculation of tube degradation induced by dryout instability in sodium-heated steam generators[J]. Nuclear Engineering and Design, 1977, 41(2): 181-191. doi: 10.1016/0029-5493(77)90108-X [16] ZHANG Y, LU T. Study of the quantitative assessment method for high-cycle thermal fatigue of a T-pipe under turbulent fluid mixing based on the coupled CFD-FEM method and the rainflow counting method[J]. Nuclear Engineering and Design, 2016, 309: 175-196. doi: 10.1016/j.nucengdes.2016.09.021 [17] CHOPRA O K, STEVENS G L, TREGONING R, et al. Effect of light water reactor water environments on the fatigue life of reactor materials[J]. Journal of Pressure Vessel Technology, 2017, 139(6): 060801. doi: 10.1115/1.4035885 -
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