微孔曝气流量与曝气管长度对水体增氧性能的影响  

Impact of microporous aeration flow and aeration tube length on oxygen transfer performance in water

作　　者：程香菊[1] 曾映雪[1] 谢骏[2] 龚望宝[2] 

机构地区：[1]华南理工大学土木与交通学院,广州510640 [2]中国水产科学研究院珠江水产研究所,广州510380

出　　处：《农业工程学报》2014年第22期209-217,共9页Transactions of the Chinese Society of Agricultural Engineering

基　　金：现代农业产业技术体系建设专项(nycytx-49-13);清华大学水沙科学与水利水电工程国家重点试验室开发研究基金(sklhse-2013-B-02);国家自然科学基金(50979118);中央高校基本科研业务费专项资金资助

摘　　要：为了探究曝气流量与曝气管长度对增氧性能的影响，在不同曝气流量、不同曝气管长度条件下进行了室内水体底部微孔曝气增氧试验。分析了曝气流量与曝气管长度对氧体积传质系数、增氧量和氧利用率的影响。研究结果表明，当曝气流量为0.27～0.55 m3/s、曝气管长为0.9～1.5 m时，所对应的氧体积传质系数在0.63～1.1 h-1变化，增氧量在6.8～12.9 g/h变化，氧利用率在6.87%～9.28%变化，且在一定的曝气管长度下，氧体积传质系数、增氧量均与曝气流量成正比，而氧利用率则与其成反比关系；在一定的曝气流量下，曝气管长度对氧体积传质系数产生的影响表现为先高后低再高的趋势；氧体积传质系数与修正的饱和溶解氧浓度是否作为增氧量的主要影响因子取决于曝气管长度；曝气流量对氧利用率较曝气管长度更为敏感。研究还发现，微孔曝气系统中存在着最优曝气管长度，使得增氧性能最佳，并建立了最优曝气管长度与曝气流量、水深、输入压力、最优初始气泡直径的相关关系式，为低碳经济下微孔曝气系统的设计和运行提供了理论依据。Microporous aeration systems have become one of the most popular aeration devices used in lakes, reservoirs and aquacultures where there is a need to increase dissolved oxygen concentration. The biggest feature of the microporous aeration aerator is that the initial bubble diameters vary with changes in the aeration tube length, the air flow rate, the submerged water depth, and the input pressure. There are many factors to affect the oxygenation performance, such as the oxygen mass transfer coefficient, oxygen utilization efficiency, and power efficiency. Many researchers consider only the impacts of a single factor or two factors on oxygen transfer performance, without considering the most important keys to affect the oxygenation performance. For this study, the diffused air flow rate and the diffuser tube length were considered the key factors of oxygenation performance to determine the aeration tube length that maximized the oxygenation performance under a given air flow rate. The oxygen mass transfer coefficient, oxygenation rate, and oxygen utilization efficiency were considered the major parameters of the oxygenation performance in this study. To explore the effects of the diffused air flow rate and the diffuser tube length on oxygen transfer performance, after placing a disc made of a coiled, microporous diffuser tube in the middle bottom of an experimental pond, a series of re-oxygenation experiments were conducted under different aeration flow rates and aeration tube lengths. The impact of the aeration flow rate and the diffuser tube length on the oxygen volume mass transfer coefficient, the oxygenation amount and the oxygenation efficiency was analyzed and discussed. The results show that when the aeration air discharge was changed from 0.27 to 0.55 m3/s and the diffuser tube length was changed from 0.9 to 1.5 m, the oxygen mass transfer coefficient increased from 0.63 to 1.1 h-1, the oxygenation rate increased from 6.8 to 12.9 g/h, and the oxygen utilization efficiency increased from 6.87% to 9.28%. Un

关 键 词：水处理 水产养殖 氧 微孔曝气 曝气流量 曝气管长度 增氧性能 

分 类 号：S9[农业科学—水产科学]