共查询到19条相似文献,搜索用时 97 毫秒
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正方形沉淀池内部水流运动模拟及设计应用 总被引:1,自引:1,他引:0
针对江苏新纪元环保有限公司自主研发的上下全截面正方形沉淀澄清池进行水流运动模拟及分析。正方形沉淀澄清池的水力特性对其沉淀效果有很大影响,在沉淀池水力设计中应通过对池型以及各种几何参数的优化,使其池内回流区范围尽可能减小,并且尽量使池内垂直断面上流速均匀平稳,研究中主要利用模型模拟正方形沉淀澄清池在不同进水流速和不同挡板布置形式下的水流流场,经过分析比较出较为合理的沉淀池运行工况以及较为合适的挡板布置形式,进而提高沉淀池的运行效率。 相似文献
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利用一种半解析半离散的数值方法来求解偏微分方程,从而确定二次沉淀池的流态。该方法具有精度高、速度快、占用计算机内存小的特点。所编制软件可在486微机上运行。计算结果与文献相比较,一致性很好,从而验证了本文方法的正确性。还给出了池型尺寸变化对池中心上部水流死区的影响,为具体设计者提供了参考依据。为进一步的优化设计创造了条件。 相似文献
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Taking the distributing calculation of velocity and concentration as an example,the paper established a series of governing equations by the vorticity-stream function method, and dispersed the equations by the finite differencing method.After figuring out the distribution field of velocity, the paper also calculated the concentration distribution in sedimentation tank by using using the two-dimensional concentration transport equation.The validity and feasibility of the numerical method was verified through comparing with experimental data.Furthermore,the paper carried out a tentative exploration into the application of numerical simulation of sedimentation tanks. 相似文献
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IntroductionInwatertreatmenttechnology ,themostcommonlyusedmethodofsolidliquidseparationisgravitationalsedimentation .Fromstatistics,onequarterofthetotalinvestmentofthewastewatertreatmentplantisusedforsedimentationtanks (Swamee ,1 996) .Withthedevelopmentofc… 相似文献
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Application of numerical simulation on optimum design of two-dimensional sedimentation tanks in the wastewater treatment plant 总被引:1,自引:0,他引:1
ZENG Guang-ming ZHANG Shuo-fu QIN Xiao-sheng HUANG Guo-he LI Jian-bing 《环境科学学报(英文版)》2003,15(3):346-350
The paper establishes the relationship between the sttling efficiency and the sizes of the sedimentation through the process of numerical simulation,which is taken as of the constraints to set up a simple optimum dsigning model of sedimentation tank.The feasibility and advantages of this model based on numerical calculation are verified through the application of practical case. 相似文献
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Numerical simulation of the sedimentation of cylindrical pollutant particles in fluid 总被引:5,自引:1,他引:5
The sedimentation of cylindrical pollutant particles which fall through a fluid is investigated. Differing from previous research work,particle oscillation and effect of particle on the fluid are considered, and the torque exerted on a particle when viscous fluid flow around a particle is got through experiment and included in the numerical simulation. The computational results showed that the sedimentation velocities of particle increase slowly with the increase of particle aspect ratio 9. For disk-like particle, when the motion direction of particle is parallel to axis of particle, particle falls more slowly than the case of perpendicular to axis of particle; while for rod-like particle, it is inverse. For sedimentation of a crowd of high-frequency oscillating cylindrical particles with arbitrary initial orientation, both vertical velocity and horizontal velocity oscillate dramatically, the degree of oscillation of the former is stronger than the later. A crowd of particles fall more quickly than an isolated particle. Particles tend to strongly align in the direction of gravity. The computational results agreed well with the experimental ones and helpful for controlling of pollutant particles. 相似文献
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以长沙市某污水处理厂二沉池为例,采用多相流混合物模型与k-ε湍流模型结合对辐流式二沉池内速度场和污泥浓度场进行了数值模拟.以出水口悬浮物浓度(SS)为响应目标,对影响二沉池沉淀效果的3个影响因素(进水口流速、颗粒污泥粒径、挡板的淹没深度)进行中心复合设计(central composite design,CCD),并经响应表面法分析得到影响出水SS的二次回归模型,确定了二沉池沉降的最佳条件:进水口流速为0.03m·s-1,颗粒污泥粒径为220.41μm,挡板的淹没深度为3.45m,采用数值仿真模拟实验得到出水口悬浮物浓度值为2.4mg·L-1,较优化之前的仿真结果一周平均值6.7mg·L-1相比,其处理效率提高了64.2%.采用数值仿真和响应表面法结合对二沉池工艺条件进行优化研究,可以加速寻优过程,是工艺优化的辅助工具. 相似文献
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为探索在曝气池气液两相流数值模拟中气泡尺寸对两相流流动特性的影响,采用大涡模拟和欧拉-拉格朗日方法建立了曝气池两相流数学模型.基于模型实验得到的工程上常用的微孔曝气盘的气泡尺寸分布,在数值模拟中设定了3种气泡尺寸分布方案,比较了不同的气泡尺寸设定方案对计算曝气池内水流流速和气含率等参数的影响.结果表明,气泡尺寸对水流流场具有较大的影响,而对气含率分布的影响在大部分区域不明显,只在气含率峰值附近影响较显著;使用多组气泡尺寸的设定方案可以提高计算结果的准确性,采用单组气泡尺寸时应尽量使其接近平均气泡直径. 相似文献
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数值模型模拟在污水处理厂二沉池设计、运行操作和优化方面具有无可替代的优势,对现有数值模型进行归纳与总结对实际应用中选择及建立模型至关重要。介绍了用于二沉池数值模拟的欧拉-拉格朗日模型、欧拉-欧拉模型和混合模型等多相模型的原理,对各模型的适用性进行阐述,总结其优点和不足;阐述了单相模型在污泥沉降中的应用原理,提出单相模型通过耦合单独的固相输运方程来描述污泥沉降运动规律,其在二沉池污泥浓度分布预测上优于多相模型;论述了污泥沉降速度模型研究现状,其中包含利用批量沉降试验的污泥间歇沉降模型和描述污水处理厂二沉池连续流污泥沉降模型;较为系统地综述了二沉池污泥负荷、几何结构、温度等因素对二沉池内水质模拟结果的影响;最后对污水处理厂二沉池数学模型的选择和沉降模型后续研究进行了展望。
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考虑悬浮物吸附沉降作用的海湾放射性核素迁移数值模拟 总被引:2,自引:0,他引:2
首次建立了考虑悬浮物对放射性核素的吸附沉陷影响的海湾放射性核素迁移数值模型,并对模型进行了检验,对所建模型和先前不考虑悬浮物吸附沉陷影响的放射性核素迁移模型进行了模拟对比分析,充分体现了考虑悬浮物对核索迁移影响进去的必要性。应用本模型对大亚湾核电站诽出的放射性污染物137Cs在大鹏澳内的迁移分布状况进行了模拟分析,其模拟结果与实测结果吻合良好,表明了本模型的可靠性,可为放射性污染源对海湾环境影响评价提供科学依据。 相似文献