高压微雾蒸发排放低放废液数值模型与验证  

Numerical modeling and validation of evaporation and discharge of low-level radioactive wastewater based on high-pressure spray technology

作　　者：杨德睿 吴思远 聂保杰 顾卫国[1] 王博 王德忠[1] 张爱玲 YANG Derui;WU Siyuan;NIE Baojie;GU Weiguo;WANG Bo;WANG Dezhong;ZHANG Ailing(School of Nuclear Science and Engineering,Shanghai Jiao Tong University,Shanghai 200240,China;Ministry of Ecology and Environment,Nuclear and Radiation Safety Center,Beijing 100082,China)

机构地区：[1]上海交通大学核科学与工程学院,上海200240 [2]生态环境部核与辐射安全中心,北京100082

出　　处：《核技术》2023年第9期57-65,共9页Nuclear Techniques

基　　金：国家自然科学基金(No.11905305)资助。

摘　　要：核设施运行中会产生一定低水平放射性废液,通常经净化后以液态流出物形式在控制范围内进行海洋排放。内陆核设施往往缺乏弥散条件优良的受纳水体,并考虑公众接受度,低水平放射性废液的处置成为内陆核设施发展的难点之一。高压微雾蒸发技术利用高压喷嘴将液态流出物进行雾化,并控制载带气体条件使微雾充分蒸发,进行气载排放,具有一定应用前景。综合考虑微雾流动和传热传质模型,发展了用于分析微雾载带蒸发的数值方法,并研制了高压微雾蒸发示范系统,分别从流动蒸发过程中微雾粒径变化、微雾密度和沉积率三个角度对数值方法进行了实验验证。结果表明:建立的数值方法与实验结果偏差在15%以内,可用于不同厂址场景下低水平放射性废液气载排放工艺设计。[Background]Low-level radioactive wastewater(LLW)is generated during the operation of nuclear facilities.Usually,LLW is discharged directly into the ocean in the form of liquid effluent after purification under the discharge management limits.However,discharging LLW into inland water bodies is difficult for inland nuclear facilities because of the poor dispersion and the lack of public acceptance.Thus,LLW disposal has become one of the challenges limiting the development of inland nuclear facilities.Liquid-to-gas discharge,which is based on high-pressure spray evaporation technology,is an alternative solution for LLW disposal for inland nuclear facilities.[Purpose]This study aims to develop and validate a model for simulating spray flow and evaporation to assess the design feasibility.[Methods]A numerical method coupling a two-phase flow model,mass transfer model,and heat transfer model were established to describe droplet evaporation during the flow process.To validate this numerical method,a sample high-pressure spray evaporation system was developed which included three key subsystems:carrier gas generation,source term generation,and measurement systems.Finally,considering evaporation and deposition factors,three experimental cases were designed for experimental comparison of the droplet diameter,number,and deposition rate among these cases.[Results]The comparison results show that the numerical method is highly consistent with the experimental results,with a maximum uncertainty of 15%.[Conclusions]The numerical model developed in this study can be used for the technological design of liquid-to-gas LLW discharge based on high pressure spray evaporation technology.

关 键 词：低放废液 高压微雾 气载排放 数值模型 

分 类 号：TL99[核科学技术—核技术及应用]