蒸汽发生器一次侧进出口管嘴流阻的数值模拟研究

Numerical simulation study on flow resistance of steam generator primary nozzles

蒸汽发生器一次侧进出口管嘴的流阻是核电厂一回路流阻的重要组成部分。本文采用计算流体力学(CFD)方法,对蒸汽发生器一次侧进出口管嘴的流阻进行了数值模拟研究。首先探讨了Standard k-ε模型、RNG k-ε模型及Realizable k-ε模型的适用性。之后,选择合适的湍流模型研究了倒角对流阻的影响,从而明确了蒸汽发生器一次侧进出口管嘴流阻的计算方法及主要影响因素。研究结果对蒸汽发生器的设计具有一定的参考价值,对核电厂其它设备流阻的计算也有一定的借鉴意义。

Background： For the nuclear power plant, the flow resistance of steam generator primary nozzles is an important part of the primary flow resistance. Consequently, the study on the calculation method of the flow resistance and that on its main influence factor are of great significance to the design of the nuclear power plant. In engineering, the k-e models, including Standard k-e model, RNG k-e model and Realizable k-e model, are widely applied to the simulation of flow field. Purpose： We aim to make sure which of these k-e models is the most appropriate to calculate the flow resistance of steam generator primary nozzles. And the influence of the chamfer on the flow resistance was studied. Methods： First of all, the k-e models mentioned above were respectively used to simulate the flow field and calculate the flow resistance. The applicabilities of Standard k-c model, RNG k-e model and Realizable k-e model were discussed via comparing the numerical results with those of the experiment. Then, the most appropriate model was adopted to study the influence of the chamfer on the flow resistance. Results： Compared with other k-e models, Realizable k-c model was the most appropriate one for the calculation of the flow resistance of steam generator primary nozzles. The chamfer was helpful for reducing the flow resistance, especially for the outlet nozzle. Conclusion： Numerical modeling can be used to determine an appropriate computing method for flow resistance of steam generator primary nozzles, and study the main influence factor on the flow resistance. This work may have certain reference value to the design of steam generators and the computation for flow resistance of other equipment in the nuclear power plant.