连续式咸淡水混合搅拌反应器混合性能研究  

Mixing Performance in Continuous Salt and Freshwater Mixing and Stirring Reactor

作　　者：李杰 陈滇豫 胡笑涛[1] 何名淞 LI Jie;CHEN Dianyu;HU Xiaotao;HE Mingsong(Key Laboratory of Agricultural Soil and Water Engineering in Arid and Semiarid Areas,Ministry of Education,Northwest A&F University,Yangling,Shaanxi 712100,China)

机构地区：[1]西北农林科技大学旱区农业水土工程教育部重点实验室,陕西杨凌712100

出　　处：《农业机械学报》2024年第11期417-428,共12页Transactions of the Chinese Society for Agricultural Machinery

基　　金：国家重点研发计划项目(2022YFD1900502)。

摘　　要：为合理开发利用咸水资源,优化农田灌溉设施前端连续式咸淡水混合搅拌反应器结构和运行参数,探究了搅拌转速和桨叶宽度对不同类型搅拌器咸淡水混合性能的影响。以直径为290 mm的双层桨叶搅拌器为研究对象,采用Realizable k-ε模型和欧拉多相流模型进行数值模拟并利用试验结果对其进行验证。系统分析不同搅拌器结构在不同搅拌转速和桨叶宽度下的湍动能、速度流场、咸水体积分数分布、混合均匀所需时间及搅拌器功耗,发现随着搅拌转速和桨叶宽度增加,三叶开启式搅拌器与组合锚式搅拌器湍动能和液体流速均增加,反应釜内咸水体积分数也随之发生显著变化,到达混合均匀状态所需时间缩短,出口处咸水均匀度和搅拌器功率均呈上升趋势。整体来说,转速对上述指标的影响较桨叶宽度更为显著,另外,2种搅拌器类型中相关指标受转速和桨叶宽度变化的影响差异明显。与三叶开启式搅拌器相比,组合锚式搅拌器达到完全混合均匀状态所需时间最小值虽然低6.8%,但其搅拌功耗却高10%左右。综合考虑灌溉作物水量需求、混合效率和设备能耗等因素,推荐采用较低转速(90 r/min)、宽桨叶(50 mm)的三叶开启式搅拌器,该配置在咸淡水混合过程中能够有效保障混合效率,并在连续混合设备中有效控制能耗的同时满足实际应用需求。研究结果可为连续式咸淡水混合搅拌反应器设计优化提供参考。In order to rationally develop and utilize brackish water resources,the structure and operating parameters of a continuous first-but-mix stirring reactor at the front end of an agricultural irrigation system were optimized.The effects of mixing speed and paddle width on the mixing performance were investigated by using a double-layer paddle mixer with a diameter of 290mm.Realizable k-εmodel and Eulerian multiphase flow model were used for numerical simulations and validated by experimental data.The analysis of turbulent kinetic energy,velocity flow field,brackish water volume fraction distribution,mixing time and power consumption of the agitator showed that the increase in mixing speed and paddle enhanced the turbulence and flow velocity for both the threebladed open type and the combined anchor type.It was found that the rotational speed had a greater effect on the studied parameters than the paddle width.Overall,the effect of rotational speed on the studied parameter was significantly more than paddle width,in addition to the significant difference in the effect of these two factors on the two types of agitators.Compared with the three-bladed open agitator,the combined anchor agitator reduced the agitation time by 6.8%,but increased the agitation power consumption by about 10%.Taking into account of crop irrigation requirements,mixing efficiency and equipment energy consumption,it was recommended to use a three-blade open agitator with a lower speed(90r/min)and a wide paddle(50mm).This configuration can effectively balance the mixing efficiency and energy consumption of a continuous salt and freshwater mixing and stirring system.The results can provide a reference for the design optimization of continuous brackish freshwater mixing and stirring reactors.

关 键 词：咸水灌溉 连续式搅拌反应器 数值模拟 搅拌器 混合性能 

分 类 号：S224.9[农业科学—农业机械化工程]