Study on Operating Characteristics and Water Hammer Phenomenon of Lead-Bismuth Eutectic Commutator with Enclosed Structure
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摘要: 为研究闭式换向器在液态铅铋合金(LBE)介质换向过程中的流量稳定性及其适用性,采用FLUENT软件结合重叠网格方法对三通切换阀形式的闭式换向器换向时上游的压力与速度波动进行计算分析。结果显示,换向过程中,阀芯启动及停止运动时产生水锤,水锤波以介质声速在管道中传播,从而影响管道内压力和速度的分布,水锤波的峰值大小与介质密度、阀芯运动速度成正比,水锤波频率不受阀芯运动速度影响。由于水锤波的波峰值较大,使此类型闭式换向器在LBE下换向动作时上游管道难以维持稳定流量并威胁装置安全,故在LBE流量标定装置中不适用。
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关键词:
- 闭式换向器 /
- 液态铅铋合金介质(LBE) /
- 水锤 /
- 流量标定装置
Abstract: In order to study the flow stability and applicability of the commutator with enclosed structure in the process of liquid lead-bismuth eutectic (LBE) medium commutation, FLUENT software combined with overlapping grid method is used to calculate and analyze the pressure and velocity fluctuations upstream of the commutator with enclosed structure in the form of three-way switching valve during commutation. The results show that in the process of commutation, the water hammer is produced when the valve element starts and stops, and the water hammer wave propagates in the pipe at the medium sound velocity, thus affecting the distribution of pressure and velocity in the pipe. The peak value of the water hammer wave is proportional to the medium density and the movement speed of the valve element, and the frequency of the water hammer wave is not affected by the movement speed of the valve element. Because the peak value of the water hammer wave is large, it is difficult for the upstream pipe of this type of commutator with enclosed structure to maintain a steady flow and threaten the safety of the device during commutation operation under LBE, so it is not suitable for LBE flow calibration device. -
表 1 不同阀芯运动速度2个压力峰值
Table 1. Two Pressure Peaks with Different Spool Movement Speeds
阀芯运动
速度/( m·s−1)阀门启动时刻
压力峰值/MPa阀门停止时刻
压力峰值/MPa0.9 8.85 9.44 1.8 17.43 18.84 3.6 34.44 30.38 18 168.63 245.45 表 2 水与LBE流动物性参数
Table 2. Flow Parameters of Water and LBE
介质 密度/
(kg·m−3)动力粘度/
(Pa·s)体积模
量/Pa声速/
( m·s−1)水 998.2 0.0010 $ 2.2\times {10}^{9} $ 1484 LBE 10264.0 0.0016 $ 3.1\times {10}^{10} $ 1729 -
[1] SHIMADA T, MAHADEVA D V, BAKER R C. Further investigation into a water flow rig related to calibration[J]. Flow Measurement and Instrumentation, 2010, 21(4): 462-475. doi: 10.1016/j.flowmeasinst.2010.06.003 [2] JOUKOWSKI N E. Memoirs of the imperial academy society of St. Petersburg[J]. Proceedings of the American Water Works Association, 1898(24): 341-424. [3] NIKPOUR M R, NAZEMI A H, DALIR A H, et al. Experimental and numerical simulation of water hammer[J]. Arabian Journal for Science and Engineering, 2014, 39(4): 2669-2675. doi: 10.1007/s13369-013-0942-1 [4] FENG T T, ZHANG D L, SONG P, et al. Numerical research on water hammer phenomenon of parallel pump-valve system by coupling FLUENT with RELAP5[J]. Annals of Nuclear Energy, 2017, 109: 318-326. doi: 10.1016/j.anucene.2017.05.049 [5] 胡坤, 顾中浩, 马海峰. ANSYS CFD疑难问题实例详解[M]. 北京: 人民邮电出版社, 2017: 263-264. [6] 戎利建, 张玉妥, 陆善平. 铅与铅铋共晶合金手册——性能、材料相容性、热工水力学和技术(2007版)[M]. 北京: 科学出版社, 2014: 9-61. [7] 吕鸣宇,张斌,裴晓迟. 流量标准装置中闭式换向器对流量测量的影响[J]. 信息系统工程,2012(8): 109,103. [8] 全国流量容量计量技术委员会. 液体流量计器具检定系统表检定规程: JJG 2063—2007[S]. 北京: 中国标准出版社, 2008: 3-4.