厚壁三通管件非等温横向射流的数值模拟研究

为了研究压水堆核电站冷却剂系统中厚壁三通管件的热应力问题,模拟了速度比分别为0.05和0．5条件下的非等温横向射流,并通过固体区域与流体区域的耦合传热计算,获得了厚壁管件的温度分布。计算基于有限容积法,采用κ－ε紊流模型,计算结果与实验吻合良好。通过研究流速比横向射流的流动和传热特性,从流动机理上考察了流动结构对构件温度分布及热应力的影响,指出在实际运行中可能对厚壁三通管件产生热冲击,从而引起构件热疲劳破坏的主要因素。定性地讨论了不同流速比下构件承受的热冲击状况,为运行参数及构件的优化设计提供了理论依据。

Numerical Simulation of Non-isothermal Jetinto Crossflow for T-junction Pipe with Thick Wall

The present work is to investigate the three-dimensional non-isothermal turbulent jet into crossflow in a thick-wall T-junction pipe, which is commonly subject to the greatest thermal stress in the pressurized water reactor (PWR) cooling system. Two cases with low jet-to-crossflow velocity ratios of 0.05 and 0. 5 are computed, with a finite-volume numerical procedure utilizing k-ε turbulent model. Temperature of the pipe is acquired by thermally coupling with the fluid. Compariso of the computations with measured data shows good qualitative agreement. Via analysis of the flow and thermal characteristics, influence of the flow structure on the temperature distribution and thermal stress of the component is studied. Major factors causing instantaneous thermal shock of the component are explored. Optimal flow rates are discussed to reduce the thermal stress.