脱硫废水烟气喷射蒸发流动特性实验研究
摘要：确保喷雾液滴在接触烟道壁面前完全蒸发，是保障电站脱硫废水在锅炉尾部烟道内蒸发处理安全运行的关键。喷雾液滴的破碎、聚并等动力学行为，以及液滴群的粒径分布和速度等因素的影响机制，是喷雾蒸发的主要特性。设计搭建了热态风洞实验台，利用激光粒度分析仪和粒子图像测速仪（particle image velocimeter，PIV），在不同的引射空气压力、喷嘴水流量，以及风速、加热空气温度等条件下，对喷雾液滴群的粒径变化和速度变化进行了测量和分析。实验结果表明：以大液滴形态离开喷嘴的射流在引射气流的携带作用下，因破碎而形成小液滴，而后液滴间聚并效果会显现出来。液滴初始粒径仅与引射气体压力和水流量有关；风速的提高一定程度上会促进液滴间的聚并。提高高压气体压力、温度、风速以及减小水流量均有助于提高液滴群速度，其中提高风速对液滴群的增速效果最为明显。研究结果为喷雾的数值模拟及工程应用改进方向提供了参考。
Abstract:The complete evaporation of flue gas desulfurization (FGD) wastewater droplets before they reach the flue duct wall is the key of safe operation of FGD wastewater treatment system in tail flue duct in thermal power plants. The main characteristics of spray evaporation include pneumatic behaviors such as breakup and polymerization, influence mechanism of droplet group size distribution and velocity. A wind tunnel was designed and constructed, and the particle size distribution and velocity of the sprayed droplet group were measured and analyzed by laser particle size analyzer and particle image velocimetry (PIV) system in different inlet conditions of injected gas pressure, nozzle water flow rate, wind speed and air heating temperature. The experimental results show that the droplets injected from the nozzle are relative bigger initially and will become smaller because of breakup. Then the droplets are polymeric. The initial particle size of the droplet is only related to the injected gas pressure and water flow. The increase of wind speed will slightly contribute to the aggregation between the droplets. Increasing the pressure of the gas, temperature, wind speed, and reducing the water flow will all contribute to the speed of the droplet group. Especially, the effect of wind speed is more obvious. The results provide the reference for the spray numerical simulation and improvement direction of spray evaporation in engineering application.
标题：脱硫废水烟气喷射蒸发流动特性实验研究
title:Experimental Study on Characteristics of Spraying Evaporation Flow of FGD Wastewater in Flue Gas
作者：吴文庆,杜小泽,杨立军
authors:Wenqing WU,Xiaoze DU,Lijun YANG
关键词：喷雾蒸发,液滴破碎,液滴粒径,平均速度,
keywords:spray and evaporate,droplet breakup,droplet diameter,average velocity,
发表日期：2020-10-30
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