排风流与喷淋液滴的流动及传热特性研究  

Study on flow and heat transfer characteristics of exhaust airflow and spray droplets

作　　者：陈世强 李瑾 张艺才 吴志荣 樊思雨 吴涛 戚子特 CHEN Shiqiang;LI Jin;ZHANG Yicai;WU Zhirong;FAN Siyu;WU Tao;QI Zite(School of Resource&Environment and Safety Engineering,Hunan University of Science and Technology,Xiangtan 411201,Hunan,China;School of Civil Engineering,Hunan University of Science and Technology,Xiangtan 411201,Hunan,China;Dongpang Coal Mine Jizhong Energy Group,Xingtai 054000,Hebei,China)

机构地区：[1]湖南科技大学资源环境与安全工程学院,湖南湘潭411201 [2]湖南科技大学土木工程学院,湖南湘潭411201 [3]冀中能源股份有限公司东庞矿,河北邢台054000

出　　处：《安全与环境学报》2023年第6期2042-2050,共9页Journal of Safety and Environment

基　　金：国家自然科学基金项目(51774134);交通运输部交通运输行业重点科技项目(2021 MS5126);广西交通运输行业重点科技项目(桂交便函[2021]148号18)。

摘　　要：为研究矿井排风与喷淋液滴的对流传热过程,构建了喷淋扩散塔模型,通过CFD对喷淋液滴流动及传热过程进行仿真。首先,分析了扩散塔中连续相、离散相速度场;随后,以单液滴运移过程为基础,结合理论公式,得到了液滴所受单位质量曳力、Nu模拟值及理论值;最后,针对液滴群传热过程,分析了液滴运移轨迹、温度变化规律及传热热流量。结果表明:排风在出口内轮廓线边角处达到最大速度时,风吹损失的液滴从出口内轮廓线边角处逃逸;上喷液滴的Nu模拟值及理论值变化规律相似,两者相互验证,表现为在上升阶段随高度增加而减小,下降阶段出现振荡趋势;当液滴粒径小于0.8 mm时,传热主要受粒径影响,当液滴粒径超过0.8 mm时,传热受粒径和喷淋速度两者共同影响;考虑风吹水损率、捕集液滴温度标准偏差及传热热流量,液气速度比0.5,液滴粒径1.2 mm,热回收效果最好。To study the convective heat transfer process of mine exhaust and spray droplets,the mathematical and physical model of the spray diffusion tower was built.The mesh was divided into a physical model and the mesh independence was verified.After the verification,the mesh was imported into CFD,and the Discrete Phase Model(DPM)was used to simulate the flow and heat transfer process of spray droplets.Firstly,the velocity field of the continuous phase and discrete phase in the diffusion tower is analyzed,and the variation regulation of water loss rate under different working conditions is obtained.Subsequently,based on the single droplet transport process,combined with the droplet control equation and heat transfer model,the drag force per unit mass,Nu simulation value,and theoretical value of the droplet were obtained.Finally,the droplet migration trajectory,temperature variation,and heat transfer flow rate were analyzed for the droplet group heat transfer process,and the optimal droplet size and liquid-gas velocity ratio were obtained.The results show that the maximum velocity of exhaust air and spray droplets is about 16.57 m/s and 10 m/s at the edge corner of the contour line inside the outlet,the droplets lost by the wind escape from the edge corner of the exit contour line.The Nu simulation value and theoretical value of the up jet droplet have similar variation rules,which are verified by each other.In the ascending stage,they decrease with the increase of height,while in the descending stage,they have an oscillation trend.When the droplet size is less than 0.8 mm,the heat transfer is mainly affected by the droplet size,and when the droplet size is more than 0.8mm,the heat transfer is affected by both the particle size and the spray speed.Considering the loss rate of wind-blown water,a standard deviation of temperature,and heat flow rate of heat transfer,the liquid-gas velocity ratio of 0.5 and droplet diameter of 1.2 mm were selected to achieve the best heat recovery effect.

关 键 词：环境工程学 喷淋液滴 网格无关性检验 风吹水损率 液气速度比 传热热流量 

分 类 号：X752[环境科学与工程—环境工程]