不同流型下气溶胶水洗效果影响因素实验研究  

Experimental Study on Influencing Factor of Aerosol Pool Scrubbing under Different Flow Regimes

作　　者：李玉祥 吴艳 曹学武[1] LI Yuxiang;WU Yan;CAO Xuewu(School of Mechanical Engineering,Shanghai Jiao Tong University,Shanghai 200240,China)

机构地区：[1]上海交通大学机械与动力工程学院,上海200240

出　　处：《原子能科学技术》2023年第2期276-283,共8页Atomic Energy Science and Technology

摘　　要：在核电厂严重事故下,安全壳内混合气体通过喷射器注入到乏燃料水池中以降低安全壳超压失效的风险,同时减少放射性向环境的释放。本文建立了气溶胶水洗去除实验装置,研究水池对气溶胶的去除机制。开展了不同流型下通过喷射器的混合气体质量流率对气溶胶水洗净化系数(DF)的影响以及蒸汽冷凝对气溶胶去除效果的影响。结果表明:在注入流型为射流的情况下,由于射流注入区液滴拦截和惯性碰撞去除机制的增强,导致DF随着质量流率的增大而增大;在注入流型为气泡流的情况下,上升区气溶胶去除占主要作用,随着质量流率增大,气泡上升速度增快,导致气泡在水池内运动时间减少,DF降低。同时,在蒸汽存在的情况下,气溶胶去除效果明显增强,蒸汽冷凝是气溶胶去除的主要机制。During a severe accident in nuclear power plant, if passive containment cooling system fails and other pressure relief measures are also useless, the mixed gas in containment can be injected into the spent fuel pool via a injector to reduce the risk of containment overpressure failure and the release of radioactivity to the environment. A aerosol pool scrubbing facility was built to study the factors influencing the effect of aerosol pool scrubbing under the injector. This facility can perform a great variation of experiments using various measurement tools. The aerosol concentration and particle size were monitored by using the spectrometer with a 20% measurement error. TiO2powder was used as a stimulant for the aerosols in containment, and the mass median diameter ranged from 0.5 to 1.5 μm, the geometric standard deviation ranged from 1.63 to 2.15. According to the different characteristics of gas-liquid hydrodynamic behavior, the pool scrubbing process can be divided into two regions, including injection and rise zones. In the injection zone, with the flow flux increase, the gas regime changed from bubble(We<10~5) to jet regime(We≥10~5). The effect of mass flux on the aerosol removal efficiency under these two different flow regimes was studied. The decontamination factor(DF) increases with mass flux in the case of jet regime. The high-speed gas interacts with the water and causes water entrainment in the form of droplets, and then the aerosol is removed by droplet interception and inertial collision. With the increase of the mass flux, the jet length and entrained droplet fraction increase, the droplet interception and inertial impact aerosol removal mechanism are enhanced, resulting in an increase in DF. DF decreases with the increase of mass flux in the case of bubble regime. With the increase of mass flux, the aerosol removal mechanism of rising zone dominates. Although the inertial collision effect in the injection zone is enhanced, the bubble swarm rises faster, the movement time of the bubbles in the

关 键 词：射流 气泡流 蒸汽冷凝 喷射器 水洗净化系数 

分 类 号：TL364[核科学技术—核技术及应用]