蒸汽发生器传热管密度波振荡现象研究

Research on Density Wave Oscillations in Steam Generator Heat Transfer Tube

蒸汽发生器传热管内伴有两相流的产生,研究两相情况下传热管内密度波不稳定现象,对控制核反应堆安全运行有着至关重要的作用。通过数值计算,研究了双侧对流换热条件下的传热管密度波震荡(DWO)现象。引用Babcock&Wilcox公司的直流式蒸汽发生器(OTSG)实验进行计算模型的可靠性验证;将传热管双侧对流换热与壁面均匀加热条件下的流动不稳定现象进行比较;分析管内流体加热段高度、流动方向变化时,不稳定边界的移动情况。结果表明,增加加热段高度、适当减少传热管水平方向倾斜角度(50°~90°内变化)可以增加系统的稳定性。该研究可以为螺旋管式蒸汽发生器设计提供参考。

There exists two-phase flow in the heat transfer tube of the steam generator, in which the density wave oscillation(DWO) phenomenon plays a vital role in the safe operation of the nuclear reactor. This paper studies the DWO phenomenon in the tubes under bilateral convection by numerical calculation. Firstly, comparing the results of the numerical model with Babcock & Wilcox Once-Through Steam Generation(OTSG) experiment, the numerical model is verified. Secondly, the DWO boundary in different boundary heating conditions(bilateral convection and traditionally electric heating on the wall) is compared. Lastly, the movement of DWO boundary is analyzed by changing the height of the heating section and flow directions. It is found that increasing the length of the heating section and appropriately reducing the level inclination(within the range of 50 to 90 degree) of the tubes can expand the stable interval in the system. The main purpose of this paper is to provide reference and guidance for the safe operation of the steam generator.