某型应用于核电的节流文丘里管空化规律研究

Numerical simulation on cavitation of throttling Venturi tube applied in nuclear electricity

为研究应用于核电站的节流管道空化对流量限制的影响,采用数值仿真方法,结合试验结果对某型文丘里管节流装置空化后限流性能进行了研究。在不同压差工况下探讨了空化时节流管道内速度、压力的分布规律,以及压差值对流量的量化关系。在正常运行工况下,仿真结果与试验结果的流量误差为6.3%,说明数值模型比较准确。研究结果表明,空化由节流管道喉部开始产生,向下游扩展;管道压差越大,空化效果越显著;本型号设计截面在满足压差的同时,可以实现限流效果;在满足使用要求的压差下,空化可达到90%以上汽含率。喉部1/2处径向方向上,空化率呈指数型增加。

To study the influence of cavitation reaction on choked flow inside pipeline, considering computational fluid dynamics method and based on experimental results, a Venturi tube throttling device used in nuclear power plant was analyzed by numerical simulation, the evolution mechanism of physical parameters with cavitation inside the pipeline was studied under different pressure difference. Under normal operating pressure, the flow error between the simulation and experimental results is 6.3%, indicating that the numerical model is relatively accurate. The results show that the greater the pressure difference is, the more significant the cavitation effect is in the fluid domain of the pipeline. While meeting choked flow inside pipeline, it can also try to improve the flow and meet the use requirements. Under ideal pressure difference, cavitation can reach more than 90 % vapor holdup. In the radial direction of 1/2 of the throat, the calculated cavitation rate shows an exponential quantitative law.