乏燃料后处理用空气提升器仿真模型研究及验证

Simulation Study and Verification of the Air-Lift Pump for Spent Fuel Reprocessing

空气提升器广泛应用于乏燃料后处理过程中放射性料液的输送,提高其仿真精度对乏燃料后处理系统仿真具有重要意义。以动量平衡为理论基础对空气提升器进行建模研究,考虑了压力与管径对两相流的影响,采用不同的两相流压损和截面含气率计算方法建立了适用于不同管径的模型。搭建了空气提升器实验台架,通过所得到的实验数据对模型进行验证。研究发现,所建立的小管径模型对10~30 mm管径空气提升器性能的预测效果较好,最大相对误差为10.73%;当管径增大到40 mm时,升液管内的弹状流产生了与小管径不同的流动特点,使用建立的大管径空气提升器仿真模型对40 mm管径空气提升器性能进行预测,最大相对误差为8.04%。通过考虑两相流中气相在提升过程中的膨胀可以有效减小模型的误差。结果表明,所提出的空气提升器仿真模型能够较好地预测10~40 mm管径空气提升器性能。

The air-lift pump is widely used to transport radioactive liquid in the process of spent fuel reprocessing.Improving its simulation accuracy is of great significance to the simulation of spent fuel reprocessing system.The air-lift pump is modeled on the basis of momentum balance,the influence of pressure and pipe diameter on the two-phase flow is considered.Two models are established using different pressure loss and void fraction calculation methods for different pipe diameters.The experimental bench of the air-lift pump was built,and the model was verified by experimental data.The study found that the small diameter model has better prediction effect on the performance of the air-lift pump 10-30 mm pipe diameter.The maximum relative error is 10.73%.When the pipe diameter increases to 40 mm,the slug flow in the riser produces different characteristics from the small pipe diameter.The large diameter model is suitable for 40 mm pipe diameter,and the maximum relative error is 8.04%.The error of the model can be effectively reduced by considering the expansion of the gas phase in the two-phase flow during the lifting process.The results show that the proposed model can better predict the performance of the air-lift pump with a diameter of 10 mm to 40 mm.