燃煤电厂连排水蒸发特性和粒径分布的数值模拟  

Numerical Simulation of Evaporation Characteristics and Particle Size Distribution of Boiler Drainage in Coal-fired Power Plant

作　　者：李春建 曾澄光 李宗锟 练树生 黄梓淦 马晓茜[2] LI Chunjian;ZENG Chengguang;LI Zongkun;LIAN Shusheng;HUANG Zigan;MA Xiaoqian(Guangzhou Zhongdianlixin Thermal Power Co.,Ltd.,Guangzhou,Guangdong 511340,China;School of Electric Power,South China University of Technology,Guangzhou,Guangdong 510641,China)

机构地区：[1]广州中电荔新热电有限公司,广东广州511340 [2]华南理工大学电力学院,广东广州510641

出　　处：《广东电力》2022年第7期141-150,共10页Guangdong Electric Power

基　　金：广州发展集团重点产学研科研项目(T-2030201130)。

摘　　要：某330 MW燃煤电厂产生的大量连排水没有得到有效利用,未达到节能要求,为了对连排水的热量进行回收并利用,设计了连排水蒸发管。通过数值模拟,考察喷嘴压力、喷嘴数量、工作蒸汽流量和工作蒸汽进口温度对雾化液滴蒸发率、蒸发产物粒径分布和颗粒贴壁概率的影响。研究表明,在基础工况中,气液间存在较大的速度差和温度差,液滴迅速蒸发,出口盐分的平均粒径和粒径标准差都小于1μm。增大喷嘴压力、增加喷嘴数量、提高工作蒸汽流量和进口温度均能提高液滴蒸发率。当液滴完全蒸发时,产物粒径分布较为集中。优化试验结果表明,连排水雾化蒸发建议采用的喷嘴压力为5 MPa,喷嘴数量不少于3个,工作蒸汽流量和进口温度分别为5 kg/s以上和791 K以上。A large amount of continuous boiler drainage produced by a 330 MW coal-fired power plant has not been effectively used and can’t meet the energy-saving requirements.In order to recover and utilize the heat of the continuous drainage,a continuous drainage evaporating pipe was designed.By means of numerical simulation,the effects of nozzle pressure,numbers of nozzles,working steam flow and working steam inlet temperature on the evaporation rate of atomized droplets,particle size distribution of evaporation products and particle adhesion probability were investigated.The studies show that in the basic working conditions,there is a large velocity difference and temperature difference between gas and liquid,the droplets evaporate rapidly,and the average particle size and the standard deviation of the particle size of the outlet salt are both less than 1μm.It is able to increase the droplet evaporation rate by increasing the nozzle pressure,the numbers of nozzles,the working steam flow and inlet temperature.When the droplets evaporate completely,the particle size distribution of the product is more concentrated.The optimization test results indicate that the recommended nozzle pressure for continuous drainage atomization evaporation is 5 MPa,the numbers of nozzles are not less than three,and the working steam flow rate and inlet temperature are above 5 kg/s and 791 K respectively.

关 键 词：连排水 热量回收 喷雾蒸发 蒸发特性 数值模拟 

分 类 号：TM621.7[电气工程—电力系统及自动化] TK227.6[动力工程及工程热物理—动力机械及工程] TB115.2[理学—数学]