叶片形状对倒伞曝气机性能的影响
|
摘要
为了探究直叶片和倾斜叶片对倒伞曝气机性能的影响,获得不同叶片形状倒伞曝气机驱动下氧化沟的流场特性,以1个符合几何相似、运动相似和动力相似理论的缩比双倒伞曝气机驱动下的氧化沟模型为研究对象,采用VOF自由液面模型与标准k-ε湍流模型相结合的方法,对不同叶片形状的倒伞曝气机驱动下的氧化沟内部流动进行了三维数值模拟.结果表明,2类倒伞曝气机消耗的功率相近,叶片形状的不同影响着倒伞曝气机的充氧能力和推流能力:直叶片倒伞曝气机驱动下,氧化沟过轴截面的气相体积分数较倾斜叶片大0.66%;直叶片倒伞曝气机对表层水域的推动能力较强,而倾斜叶片倒伞曝气机则对底层流体有较强的推动能力,沟底死水区相较于直叶片倒伞曝气机减小0.70%,且倒伞曝气机附近的流体能以较快的速度流向壁面;在双倒伞曝气机驱动下,氧化沟内的流动呈对称分布,下游倒伞曝气机能够明显提升和加速来流速度.
In order to study the effect of radial straight blade and leaned blade on the performance of inverse umbrella aerator and obtain the flow characteristic of an oxidation ditch driven by two inverse umbrella aerators with different kinds of blade shape,a lab scale oxidation ditch according with geometric similarity,kinematic similarity and dynamic similarity was taken as the research object. The volume of fluid( VOF) model was adopted and the standard k-ε turbulence model was applied to close the governing equations. Through changing the blade shape of inverse umbrella aerator,three-dimensional numerical simulations were conducted. The results show that the power assumption of these two kinds of inverse umbrella aerators is much the same,the blade shape has a significant impact onoxygenation capacity and plug-flow capacity on the inverse umbrella aerator. Under the drive of inverse umbrella aerator with radial straight blade,the gas volume fraction of the section crossing the driving shaft in the oxidation ditch is 0. 66% higher than that in the oxidation ditch driven by the inverse umbrella aerator with leaned blade. While the inverse umbrella aerator with radial straight blade has a stronger ability to promote the fluid near the surface,the inverse umbrella aerator with leaned blade does better on driving fluid at the bottom of the ditch,with the dead water zone 0. 70% less than that in the ditch driven by the inverse umbrella aerator with radial straight blade. The fluid stirred by the inverse umbrella aerator with leaned blade flows to the wall at a higher speed. The flow distribution of the oxidation ditch driven by two inverse umbrella aerators is symmetrical. The downstream inverse umbrella aerator has an ability to lift and accelerate the incoming flow.
In order to study the effect of radial straight blade and leaned blade on the performance of inverse umbrella aerator and obtain the flow characteristic of an oxidation ditch driven by two inverse umbrella aerators with different kinds of blade shape,a lab scale oxidation ditch according with geometric similarity,kinematic similarity and dynamic similarity was taken as the research object. The volume of fluid( VOF) model was adopted and the standard k-ε turbulence model was applied to close the governing equations. Through changing the blade shape of inverse umbrella aerator,three-dimensional numerical simulations were conducted. The results show that the power assumption of these two kinds of inverse umbrella aerators is much the same,the blade shape has a significant impact onoxygenation capacity and plug-flow capacity on the inverse umbrella aerator. Under the drive of inverse umbrella aerator with radial straight blade,the gas volume fraction of the section crossing the driving shaft in the oxidation ditch is 0. 66% higher than that in the oxidation ditch driven by the inverse umbrella aerator with leaned blade. While the inverse umbrella aerator with radial straight blade has a stronger ability to promote the fluid near the surface,the inverse umbrella aerator with leaned blade does better on driving fluid at the bottom of the ditch,with the dead water zone 0. 70% less than that in the ditch driven by the inverse umbrella aerator with radial straight blade. The fluid stirred by the inverse umbrella aerator with leaned blade flows to the wall at a higher speed. The flow distribution of the oxidation ditch driven by two inverse umbrella aerators is symmetrical. The downstream inverse umbrella aerator has an ability to lift and accelerate the incoming flow.
引文
[1]邓荣森.氧化沟污水处理理论与技术[M].北京:化学工业出版社,2010.
[2]邓荣森,张新颖,王涛,等.氧化沟工艺的技术经济评估[J].中国给水排水,2007,23(16):37-40.DENG Rongsen,ZHANG Xinying,WANG Tao,et al.Technical and economic evaluation of oxidation ditch process[J].China water and wastewater,2007,23(16):37-40.(in Chinese)
[3]THAKRE S B,BHUYAR L B,DESHMUKH S J.Oxidation ditch process using curved blade rotor as aerator[J].International journal of environmental science&technology,2009,6(1):113-122.
[4]ADACHI T.Oxygen transfer and power consumption in an aeration system using mist and circulation flow generated by a rotating cone[J].Chemical engineering science,2015,126:625-632.
[5]王淦,彭永臻,侯红勋,等.C型倒伞表面曝气机充氧性能试验研究[J].华中科技大学学报(自然科学版),2013,41(9):91-96.WANG Gan,PENG Yongzheng,HOU Hongxun,et al.Study on oxygen mass-transfer characteristics of a turbine surface aerator with vertical shaft[J].Journal of Huazhong University of Science and Technology(natural science edition),2013,41(9):91-96.(in Chinese)
[6]潘哲,汪家权,范奎,等.几种倒伞型表面曝气机的充氧性能[J].环境工程学报,2012,6(6):1936-1940.PAN Zhe,WANG Jiaquan,FAN Kui,et al.Oxygenating properties of different inverted umbrella surface aerators[J].Chinese journal of environmental engineering,2012,6(6):1936-1940.(in Chinese)
[7]蒋成义,黄卫东,王淦,等.氧化沟流场的计算流体力学数值模型研究[J].环境科学与技术,2010,33(8):135-140.JIANG Chengyi,HUANG Weidong,WANG Gan,et al.Numerical computation of flow fields in an oxidation ditch by computational fluid dynamics model[J].Environmental science and technology,2010,33(8):135-140.(in Chinese)
[8]许丹宇,张代钧,陈园,等.卡鲁塞尔氧化沟液-固两相流动混合物模型与两相水力特性模拟[J].环境科学学报,2008,28(12):2622-2627.XU Danyu,ZHANG Daijun,CHEN Yuan,et al.A fluid and soild two-phase flow model and modeling of a Carrousel oxidation ditch[J].Acta scientiae circumstantiae,2008,28(12):2622-2627.(in Chinese)
[9]FAN L,XU N,WANG Z,et al.PDA experiments and CFD simulation of a lab-scale oxidation ditch with surface aerators[J].Chemical engineering research and design,2010,88(1):23-33.
[10]施慧明,刘艳臣,施汉昌,等.深水型表面曝气机的模拟计算与构型比较[J].环境工程学报,2008,2(2):154-159.SHI Huiming,LIU Yanchen,SHI Hanchang,et al.CFD simulation and performance comparison of surface aerator for deep aeration[J].Chinese journal of environmental engineering,2008,2(2):154-159.(in Chinese)
[11]施清华.倒伞型曝气机驱动的氧化沟流场模拟及优化[D].长沙:湖南大学,2014.
[12]魏文礼,白朝伟,郑艳,等.90°弯道明渠横向环流的大涡模拟研究[J].应用力学学报,2015,32(3):466-472.WEI Wenli,BAI Chaowei,ZHENG Yan,et al.Simulation of transverse circulation of 90°open channel using two phase gas-liquid large eddy model[J].Chinese journal of applied mechanics,2015,32(3):466-472.(in Chinese)
[13]杨锋苓,周慎杰,张翠勋.无挡板搅拌槽内的自由表面湍流流场研究[J].四川大学学报(工程科学版),2015,47(2):179-183.YANG Fengling,ZHOU Shenjie,ZHANG Cuixun.Freesurface turbulent flow in unbaffled stirred tanks[J].Journal of Sichuan University(engineering science edition),2015,47(2):179-183.(in Chinese)
[14]范茏,王志强,刘艳臣,等.双表曝机Carrousel氧化沟流态的PDA实验研究[J].合肥工业大学学报(自然科学版),2007,30(11):1454-1457.FAN Long,WANG Zhiqiang,LIU Yanchen,et al.Experimental study of the flow in a Carrousel oxidation ditch equipped with two aerators by PDA[J].Journal of Hefei University of Technology(natural science edition),2007,30(11):1454-1457.(in Chinese)
[15]丁荣,谈明高,刘厚林,等.双流道泵偏工况不同叶轮外径时压力脉动[J].排灌机械工程学报,2016,34(4):301-306.DING Rong,TAN Minggao,LIU Houlin,et al.Effects of impeller diameter on pressure pulsation in a doublechannel sewage pump under partial conditions[J].Journal of drainage and irrigation machinery engineering,2016,34(4):301-306.(in Chinese)
[16]陈斌,王炳祺,张华,等.推流器布置对氧化沟流场特性的影响[J].排灌机械工程学报,2016,34(3):227-231.CHEN Bin,WANG Binqi,ZHANG Hua,et al.Effects of propeller layout position on flow characteristics in oxidation ditch[J].Journal of drainage and irrigation machinery engineering,2016,34(3):227-231.(in Chinese)
[2]邓荣森,张新颖,王涛,等.氧化沟工艺的技术经济评估[J].中国给水排水,2007,23(16):37-40.DENG Rongsen,ZHANG Xinying,WANG Tao,et al.Technical and economic evaluation of oxidation ditch process[J].China water and wastewater,2007,23(16):37-40.(in Chinese)
[3]THAKRE S B,BHUYAR L B,DESHMUKH S J.Oxidation ditch process using curved blade rotor as aerator[J].International journal of environmental science&technology,2009,6(1):113-122.
[4]ADACHI T.Oxygen transfer and power consumption in an aeration system using mist and circulation flow generated by a rotating cone[J].Chemical engineering science,2015,126:625-632.
[5]王淦,彭永臻,侯红勋,等.C型倒伞表面曝气机充氧性能试验研究[J].华中科技大学学报(自然科学版),2013,41(9):91-96.WANG Gan,PENG Yongzheng,HOU Hongxun,et al.Study on oxygen mass-transfer characteristics of a turbine surface aerator with vertical shaft[J].Journal of Huazhong University of Science and Technology(natural science edition),2013,41(9):91-96.(in Chinese)
[6]潘哲,汪家权,范奎,等.几种倒伞型表面曝气机的充氧性能[J].环境工程学报,2012,6(6):1936-1940.PAN Zhe,WANG Jiaquan,FAN Kui,et al.Oxygenating properties of different inverted umbrella surface aerators[J].Chinese journal of environmental engineering,2012,6(6):1936-1940.(in Chinese)
[7]蒋成义,黄卫东,王淦,等.氧化沟流场的计算流体力学数值模型研究[J].环境科学与技术,2010,33(8):135-140.JIANG Chengyi,HUANG Weidong,WANG Gan,et al.Numerical computation of flow fields in an oxidation ditch by computational fluid dynamics model[J].Environmental science and technology,2010,33(8):135-140.(in Chinese)
[8]许丹宇,张代钧,陈园,等.卡鲁塞尔氧化沟液-固两相流动混合物模型与两相水力特性模拟[J].环境科学学报,2008,28(12):2622-2627.XU Danyu,ZHANG Daijun,CHEN Yuan,et al.A fluid and soild two-phase flow model and modeling of a Carrousel oxidation ditch[J].Acta scientiae circumstantiae,2008,28(12):2622-2627.(in Chinese)
[9]FAN L,XU N,WANG Z,et al.PDA experiments and CFD simulation of a lab-scale oxidation ditch with surface aerators[J].Chemical engineering research and design,2010,88(1):23-33.
[10]施慧明,刘艳臣,施汉昌,等.深水型表面曝气机的模拟计算与构型比较[J].环境工程学报,2008,2(2):154-159.SHI Huiming,LIU Yanchen,SHI Hanchang,et al.CFD simulation and performance comparison of surface aerator for deep aeration[J].Chinese journal of environmental engineering,2008,2(2):154-159.(in Chinese)
[11]施清华.倒伞型曝气机驱动的氧化沟流场模拟及优化[D].长沙:湖南大学,2014.
[12]魏文礼,白朝伟,郑艳,等.90°弯道明渠横向环流的大涡模拟研究[J].应用力学学报,2015,32(3):466-472.WEI Wenli,BAI Chaowei,ZHENG Yan,et al.Simulation of transverse circulation of 90°open channel using two phase gas-liquid large eddy model[J].Chinese journal of applied mechanics,2015,32(3):466-472.(in Chinese)
[13]杨锋苓,周慎杰,张翠勋.无挡板搅拌槽内的自由表面湍流流场研究[J].四川大学学报(工程科学版),2015,47(2):179-183.YANG Fengling,ZHOU Shenjie,ZHANG Cuixun.Freesurface turbulent flow in unbaffled stirred tanks[J].Journal of Sichuan University(engineering science edition),2015,47(2):179-183.(in Chinese)
[14]范茏,王志强,刘艳臣,等.双表曝机Carrousel氧化沟流态的PDA实验研究[J].合肥工业大学学报(自然科学版),2007,30(11):1454-1457.FAN Long,WANG Zhiqiang,LIU Yanchen,et al.Experimental study of the flow in a Carrousel oxidation ditch equipped with two aerators by PDA[J].Journal of Hefei University of Technology(natural science edition),2007,30(11):1454-1457.(in Chinese)
[15]丁荣,谈明高,刘厚林,等.双流道泵偏工况不同叶轮外径时压力脉动[J].排灌机械工程学报,2016,34(4):301-306.DING Rong,TAN Minggao,LIU Houlin,et al.Effects of impeller diameter on pressure pulsation in a doublechannel sewage pump under partial conditions[J].Journal of drainage and irrigation machinery engineering,2016,34(4):301-306.(in Chinese)
[16]陈斌,王炳祺,张华,等.推流器布置对氧化沟流场特性的影响[J].排灌机械工程学报,2016,34(3):227-231.CHEN Bin,WANG Binqi,ZHANG Hua,et al.Effects of propeller layout position on flow characteristics in oxidation ditch[J].Journal of drainage and irrigation machinery engineering,2016,34(3):227-231.(in Chinese)