沉淀池重要结构参数研究
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摘要
近年来随着生活水平的提高，城市生活污水和工业废水的排放量也逐年递增。解决城市水污染的根本出路在于建设城市污水处理厂。我国在城市污水处理厂建设方面成绩卓著，但许多己建成的污水厂由于污水处理效率不能尽如人意，迫切需要改进处理流程，如何优化主要污水处理反应容器的设计和运行已是当务之急。
本文在总结前人对平流式沉淀池的物理模拟和数学模拟成果的基础上，建立了沉淀池水流数学模型和悬浮物沉降模型，通过压力校正法求解非正交同位网格上的各项变量，最终模拟出平流式沉淀池内流速场和悬浮颗粒的浓度场分布，并经过各种工况下悬浮颗粒出水浓度的比较，得出沉淀池优化结构设计尺寸范围。
从结果分析中可以看出，沉淀池挡板的高度和沉淀池本身的高度对悬浮污染物的去除影响较大，因为挡板的高度决定了沉淀池中回流区的大小，回流区越大，污水经过的时间越短，形成短流，从而达不到预期效果；在沉淀池容积一定时，计算得出的结论同理想沉淀池一样，即沉淀池高度越小，表面积就越大，悬浮颗粒的去除率越高；当沉淀池表面积一定时，沉淀池高度的变化也会较大的影响它的运行效果，池深过小或过大均会使得沉淀池中悬浮物的去除率降低；在相同表面负荷以及其它尺寸不变的情况下，不考虑污泥斗中装有污泥的情况，进水口流速的大小对沉淀池运行效果影响不明显。
With the improvement of living standard, the discharge of domestic sewage and industrial wastewater is becoming larger. The key way to solve this problem is to construct effluent plant. In our country, the construction of effluent plant has received a great success. But the efficiency of the constructed effluent plants in removing pollutant form wastewater is not very satisfied. So, it is in urge require to optimize the design and run of the main structure of the effluent plant.
In this paper, based on the analysis and summarization of study results on settling tanks by predecessors, a mathematical model for predicting the velocity field and suspended solids transport in rectangular settling tanks is developed.
Using SIMPLE algorithm for a colocated variable arrangement, the variables can be solved. Then, the current field and the consistency distribution are finally simulated. Compare the consistency of outlet in different size tanks, an optimization design can be concluded.
The model is applied to study the effect of structural size of settling tanks on the operating efficiency of settling tanks. From the analysis of the solution, it can be seemed that the high of the reaction baffles and the high of tank itself affect the removing pollutant efficiency very much. For the high of the reaction baffles and the high of tank itself determine the circumfluence in the settling tanks, and then affect the removing pollutant efficiency. On the contrary, taking no account of the instance that the sludge full filled in mud hopper, the velocity of inlet has little influence to the removing pollutant efficiency.
本文在总结前人对平流式沉淀池的物理模拟和数学模拟成果的基础上，建立了沉淀池水流数学模型和悬浮物沉降模型，通过压力校正法求解非正交同位网格上的各项变量，最终模拟出平流式沉淀池内流速场和悬浮颗粒的浓度场分布，并经过各种工况下悬浮颗粒出水浓度的比较，得出沉淀池优化结构设计尺寸范围。
从结果分析中可以看出，沉淀池挡板的高度和沉淀池本身的高度对悬浮污染物的去除影响较大，因为挡板的高度决定了沉淀池中回流区的大小，回流区越大，污水经过的时间越短，形成短流，从而达不到预期效果；在沉淀池容积一定时，计算得出的结论同理想沉淀池一样，即沉淀池高度越小，表面积就越大，悬浮颗粒的去除率越高；当沉淀池表面积一定时，沉淀池高度的变化也会较大的影响它的运行效果，池深过小或过大均会使得沉淀池中悬浮物的去除率降低；在相同表面负荷以及其它尺寸不变的情况下，不考虑污泥斗中装有污泥的情况，进水口流速的大小对沉淀池运行效果影响不明显。
With the improvement of living standard, the discharge of domestic sewage and industrial wastewater is becoming larger. The key way to solve this problem is to construct effluent plant. In our country, the construction of effluent plant has received a great success. But the efficiency of the constructed effluent plants in removing pollutant form wastewater is not very satisfied. So, it is in urge require to optimize the design and run of the main structure of the effluent plant.
In this paper, based on the analysis and summarization of study results on settling tanks by predecessors, a mathematical model for predicting the velocity field and suspended solids transport in rectangular settling tanks is developed.
Using SIMPLE algorithm for a colocated variable arrangement, the variables can be solved. Then, the current field and the consistency distribution are finally simulated. Compare the consistency of outlet in different size tanks, an optimization design can be concluded.
The model is applied to study the effect of structural size of settling tanks on the operating efficiency of settling tanks. From the analysis of the solution, it can be seemed that the high of the reaction baffles and the high of tank itself affect the removing pollutant efficiency very much. For the high of the reaction baffles and the high of tank itself determine the circumfluence in the settling tanks, and then affect the removing pollutant efficiency. On the contrary, taking no account of the instance that the sludge full filled in mud hopper, the velocity of inlet has little influence to the removing pollutant efficiency.
引文
[1] 国家环境保护局，2001年中国环境状况公报，2001年
[2] A.I. Stamou, E.W. Adams, W. Rodi, "Numerical modeling of flow and settling in primary rectangular clarifiers.", Journal of Hydraulic Research, 27(5) 665-682
[3] 许保玖，黄河某给水沉淀池模型的试验结果及其模拟概念的研究，清华大学学报，1965，Vol(12)，67-82
[4] Takacs I., and Patry G., and Nolasco D. (1991), "Dynamic model of clarifier thickening process." Journal of Water Research, 25 (10), 1263-1271
[5] Krebs P., Stamou A.I., Garcia-Heras J.L., and Rodi W. (1996), "Influence of inlet and outlet configuration on the flow in secondary clarifiers." Water Science and Technology, 34 (5-6), 1-9
[6] Zhou S., McCorauodale J.A., and Vitasovic Z. (1992), "Influence of density on circular clarifiers with baffles." Journal of Environmental Engineering, ASCE, 118(6), 829-847
[7] Djamel Lakehal, Peter Krebs, Johan Krijgsman, and Wolfgang Rodi (1999), "Computing shear flow and sludge blanket in secondary clarifiers." Journal of Hydraulic Engineering, 253-262
[8] Camp T.R. (1946), "Sedimentation and the Design of Settling Tanks.'" Transaction, ASCE, Vol. Ⅲ, 895-936
[9] Schamber D.R., Larock B.E. (1981), "Numerical analysis of flow in sedimentation basins." Journal of Hydraulic Division, ASCE, 107(5), 575-591
[10] A.I. Stamou, E.W. Adams, W. Rodi (1989), "Numerical modeling of flow and settling in primary rectangular clarifiers." Journal of Hydraulic Research, 27(5) 665-682
[11] Zhou S., and McCorquodale, J.A. (1992), "Modeling of Rectangular Settling Tanks." Journal o f Hydraulic Engineering, ASCE, 118(10), 1391-1405
[12] DeVantier, B.A., and Larock, B.E. (1987), "Modeling Sediment-induced density currents in sedimentation basins." Journal of Hydraulic Engineering, ASCE, 113 (1), 80-94
[13] Imam E., McCorquodale J.A., and Bowtra J.K. (1983). "Numerical modeling of sedimentation tanks." Journal of Hydraulic Engineering, ASCE, 109 (12), 1740-1754
[14] 汪德爟，计算水力学，河海大学出版社，1989
[15] D.A. Lyn, A.I. Stamou, and W. Rodi, ("Flocculation in Sedimentation Tanks." Journal of Hydraulic Engineering, ASCE 118(6), 849-867
[16] 张庄，沉沙池沉淀效果的数值分析，清华大学学报(自然科学版)，1998，38(1)， 96-99
[17] 严煦世、范谨初，给水工程(第三版)，中国建筑工业出版社，1995
[18] 许保玖等，给水处理理论与设计，中国建筑工业出版社，1992：
[19] 钟淳昌，净水厂设计，中国建筑工业出版社，1986；
[20] 王洪臣，城市污水处理厂运行控制与维护管理，科学出版社，1997；
[21] 张自杰，排水工程下册(第三版)，中国建筑工业出版社，1996；
[22] 北京市市政设计研究院，简明排水设计手册，中国建筑工业出版社，1990
[23] 陈玉璞，流体动力学，河海大学出版社，1990
[24] 金忠青，N-S方程的数值解和紊流模型，河海大学出版社，1989。
[25] 陶文铨，数值传热学(第2版)，西安交通大学出版社，2001。
[26] Stamou, A.I., E.W., and Rodi,W. (1989), "Numerical modeling of flow and settling in primary rectangular clarifiers." Journal of Hydraulic Research, IAHR, 27.(5), 665-682
[27] Takamatsu T., Natio M., Shiba S., and Veda Y., "Effect of Deposit resuspension on settling basins." Journal of Environmental Engineering Division, ASCE, Vol. 100, No.EE4, Aug., 1974, pp.883-903.
[28] 董曾南等，水力学，清华大学出版社，1995
[29] 毛劲乔，曝气池气液两相流数学模型的建立与应用，河海大学硕士论文，2002
[30] 蔡金傍，沉淀池水流流态的数值模拟及结构优化研究，河海大学硕士学位论文，2002
[31] 周仕铮，周边进水式污水沉淀池模拟方法探讨和试验研究，重庆建筑工程学院学报，1988，Vol(、34)，58-67
[32] 章梓雄、董曾南，粘性流体力学，清华大学出版社，1998
[33] Ferziger,Peric M.,Computational methods for fluids dynamics,Springer,1999
[34] I.Demirdzic,M.Peric,Space conservation law in finite volume calculations of fluid flow, Int.J.for Numer.meth. in fluids,1998(8),1037-1050
[35] 吴子牛，计算流体力学基本原理，科学出版社，2001
[36] 陶文铨，计算传热学的近代发展，北京科学出版社，2000
[37] Celic I., and Rodi W., (1985), " Simulation of hydrodynamic and transport characteristics of rectangular settling tanks." Euromech 192, Transport of suspended Solids in Open Channels, 129-132, Neubiberg, Germany.
[38] Krebs P., Stamou A.I., Garcia-Heras J.L., and Rodi W., (1996), "influence of inlet and outlet configuration on the flow in secondary clarifiers." Water Science and Technology, 34.(5-6),1-9.
[39] Krebs P., Armbruster M., and Rodi W., (1998b), "Laboratory experiments of buoyancy -influenced flow in clarifiers." Journal of Hydraulic Research, 36 (5)
[40] 詹咏、吴文权、王惠民， 沉淀池中的异重流运动特性，中国给水排水，2003．1
[41] 王志东、汪德煙、赖锡军， 非正交同位网格中的SIMPLE算法，河海大学学报，2003．5
[42] Sarikaya ,H.Z. (1977) o "Turbulence Model for Discrete Settling." Journal of the Hydraulics Division, ASCE, 103, HY8,865-877
[43] Abdel-Gawsad S.M. and McCorquodale J.A., (1985), "Numerical Simulation of Rectangular Settling Tanks." J. of IAHR, o1.23, No.2, 85-100
[44] Van Marle C. and Kranenburg C, (1994), "Effects of gravity currents in circular secondary clarifiers." Journal of Environmental Engineering, ASCE, 120 (4), 943-960
[45] 叶坚，紊流模型的研究及其应用，南京水利科学研究院博士学位论文，1989．6
[46] 南国英，自由沉淀平流式沉淀池设计参数的求解，中国给水排水，1997，13(3)，30-31
[47] 罗万申，德国对二沉池的计算方法，中国给水排水，1997，13(3)，30-31
[48] 唐建国，德国二次沉淀池计算方法介绍，给水排水，1993，12，15-18
[49] 张玉先，沉淀池沉淀去除率计算和表面负荷率确定的新方法，中国给水排水，1995，11(4)，19-22
[50] Lumley D.J. and Balmer P., (1991), "Solids transport in rectangular secondary settlers." Water Supply, 9,123-132
[51] Lumley D.J., Balmer P. and Adamsson J., (1988), "Investigations of secondary settling at a large treatment plant." Water Science and Technology, 20 (5), 133-142
[52] Bretscher U., Krebs R, and Hager W.H., (1992), "Improvement of flow in final settling tanks." Journal of Environmental Engineering, ASCE, 118 (3), 307-321
[53] Bender J.H., Semon A.S., and Crosby R.M., (1987), "Don't bother with secondary clarifier distributed inlets." Water Engineering and Management, 134(12), 28-30
[2] A.I. Stamou, E.W. Adams, W. Rodi, "Numerical modeling of flow and settling in primary rectangular clarifiers.", Journal of Hydraulic Research, 27(5) 665-682
[3] 许保玖，黄河某给水沉淀池模型的试验结果及其模拟概念的研究，清华大学学报，1965，Vol(12)，67-82
[4] Takacs I., and Patry G., and Nolasco D. (1991), "Dynamic model of clarifier thickening process." Journal of Water Research, 25 (10), 1263-1271
[5] Krebs P., Stamou A.I., Garcia-Heras J.L., and Rodi W. (1996), "Influence of inlet and outlet configuration on the flow in secondary clarifiers." Water Science and Technology, 34 (5-6), 1-9
[6] Zhou S., McCorauodale J.A., and Vitasovic Z. (1992), "Influence of density on circular clarifiers with baffles." Journal of Environmental Engineering, ASCE, 118(6), 829-847
[7] Djamel Lakehal, Peter Krebs, Johan Krijgsman, and Wolfgang Rodi (1999), "Computing shear flow and sludge blanket in secondary clarifiers." Journal of Hydraulic Engineering, 253-262
[8] Camp T.R. (1946), "Sedimentation and the Design of Settling Tanks.'" Transaction, ASCE, Vol. Ⅲ, 895-936
[9] Schamber D.R., Larock B.E. (1981), "Numerical analysis of flow in sedimentation basins." Journal of Hydraulic Division, ASCE, 107(5), 575-591
[10] A.I. Stamou, E.W. Adams, W. Rodi (1989), "Numerical modeling of flow and settling in primary rectangular clarifiers." Journal of Hydraulic Research, 27(5) 665-682
[11] Zhou S., and McCorquodale, J.A. (1992), "Modeling of Rectangular Settling Tanks." Journal o f Hydraulic Engineering, ASCE, 118(10), 1391-1405
[12] DeVantier, B.A., and Larock, B.E. (1987), "Modeling Sediment-induced density currents in sedimentation basins." Journal of Hydraulic Engineering, ASCE, 113 (1), 80-94
[13] Imam E., McCorquodale J.A., and Bowtra J.K. (1983). "Numerical modeling of sedimentation tanks." Journal of Hydraulic Engineering, ASCE, 109 (12), 1740-1754
[14] 汪德爟，计算水力学，河海大学出版社，1989
[15] D.A. Lyn, A.I. Stamou, and W. Rodi, ("Flocculation in Sedimentation Tanks." Journal of Hydraulic Engineering, ASCE 118(6), 849-867
[16] 张庄，沉沙池沉淀效果的数值分析，清华大学学报(自然科学版)，1998，38(1)， 96-99
[17] 严煦世、范谨初，给水工程(第三版)，中国建筑工业出版社，1995
[18] 许保玖等，给水处理理论与设计，中国建筑工业出版社，1992：
[19] 钟淳昌，净水厂设计，中国建筑工业出版社，1986；
[20] 王洪臣，城市污水处理厂运行控制与维护管理，科学出版社，1997；
[21] 张自杰，排水工程下册(第三版)，中国建筑工业出版社，1996；
[22] 北京市市政设计研究院，简明排水设计手册，中国建筑工业出版社，1990
[23] 陈玉璞，流体动力学，河海大学出版社，1990
[24] 金忠青，N-S方程的数值解和紊流模型，河海大学出版社，1989。
[25] 陶文铨，数值传热学(第2版)，西安交通大学出版社，2001。
[26] Stamou, A.I., E.W., and Rodi,W. (1989), "Numerical modeling of flow and settling in primary rectangular clarifiers." Journal of Hydraulic Research, IAHR, 27.(5), 665-682
[27] Takamatsu T., Natio M., Shiba S., and Veda Y., "Effect of Deposit resuspension on settling basins." Journal of Environmental Engineering Division, ASCE, Vol. 100, No.EE4, Aug., 1974, pp.883-903.
[28] 董曾南等，水力学，清华大学出版社，1995
[29] 毛劲乔，曝气池气液两相流数学模型的建立与应用，河海大学硕士论文，2002
[30] 蔡金傍，沉淀池水流流态的数值模拟及结构优化研究，河海大学硕士学位论文，2002
[31] 周仕铮，周边进水式污水沉淀池模拟方法探讨和试验研究，重庆建筑工程学院学报，1988，Vol(、34)，58-67
[32] 章梓雄、董曾南，粘性流体力学，清华大学出版社，1998
[33] Ferziger,Peric M.,Computational methods for fluids dynamics,Springer,1999
[34] I.Demirdzic,M.Peric,Space conservation law in finite volume calculations of fluid flow, Int.J.for Numer.meth. in fluids,1998(8),1037-1050
[35] 吴子牛，计算流体力学基本原理，科学出版社，2001
[36] 陶文铨，计算传热学的近代发展，北京科学出版社，2000
[37] Celic I., and Rodi W., (1985), " Simulation of hydrodynamic and transport characteristics of rectangular settling tanks." Euromech 192, Transport of suspended Solids in Open Channels, 129-132, Neubiberg, Germany.
[38] Krebs P., Stamou A.I., Garcia-Heras J.L., and Rodi W., (1996), "influence of inlet and outlet configuration on the flow in secondary clarifiers." Water Science and Technology, 34.(5-6),1-9.
[39] Krebs P., Armbruster M., and Rodi W., (1998b), "Laboratory experiments of buoyancy -influenced flow in clarifiers." Journal of Hydraulic Research, 36 (5)
[40] 詹咏、吴文权、王惠民， 沉淀池中的异重流运动特性，中国给水排水，2003．1
[41] 王志东、汪德煙、赖锡军， 非正交同位网格中的SIMPLE算法，河海大学学报，2003．5
[42] Sarikaya ,H.Z. (1977) o "Turbulence Model for Discrete Settling." Journal of the Hydraulics Division, ASCE, 103, HY8,865-877
[43] Abdel-Gawsad S.M. and McCorquodale J.A., (1985), "Numerical Simulation of Rectangular Settling Tanks." J. of IAHR, o1.23, No.2, 85-100
[44] Van Marle C. and Kranenburg C, (1994), "Effects of gravity currents in circular secondary clarifiers." Journal of Environmental Engineering, ASCE, 120 (4), 943-960
[45] 叶坚，紊流模型的研究及其应用，南京水利科学研究院博士学位论文，1989．6
[46] 南国英，自由沉淀平流式沉淀池设计参数的求解，中国给水排水，1997，13(3)，30-31
[47] 罗万申，德国对二沉池的计算方法，中国给水排水，1997，13(3)，30-31
[48] 唐建国，德国二次沉淀池计算方法介绍，给水排水，1993，12，15-18
[49] 张玉先，沉淀池沉淀去除率计算和表面负荷率确定的新方法，中国给水排水，1995，11(4)，19-22
[50] Lumley D.J. and Balmer P., (1991), "Solids transport in rectangular secondary settlers." Water Supply, 9,123-132
[51] Lumley D.J., Balmer P. and Adamsson J., (1988), "Investigations of secondary settling at a large treatment plant." Water Science and Technology, 20 (5), 133-142
[52] Bretscher U., Krebs R, and Hager W.H., (1992), "Improvement of flow in final settling tanks." Journal of Environmental Engineering, ASCE, 118 (3), 307-321
[53] Bender J.H., Semon A.S., and Crosby R.M., (1987), "Don't bother with secondary clarifier distributed inlets." Water Engineering and Management, 134(12), 28-30