大功率泥泵空化性能研究
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摘要
泥泵广泛应用于江河湖泊的清淤以及河道的疏浚和维护工作之中。泥泵工作时,由于某些因素的影响,引起空化作用。空化发生后,泥泵产生噪声和振动,导致其工作效率显著下降,严重时甚至无法正常工作。因此,如何提高泥泵的空化性能是流体机械领域的一个重要研究方向。
随着计算机性能的不断提高以及计算流体力学技术的发展,数值模拟成为了设计泥泵和分析泥泵内部流场的一种重要方法。数值模拟可以大大的减少试验的工作量,并且能对试验中无法测量的数据进行预估,缩短工作时间,提高工作的可靠性和经济性。
本文以计算流体力学为基础,应用商业CFD软件FLUENT对泥泵流道内的空化流场进行了数值模拟。选取三种典型工况:设计流量Q_1 = 5000 m~3/h、小流量Q_2 = 3000 m~3/h以及大流量Q_3 = 7000 m~3/h。选择两种泥浆浓度:10%和20%,当泥浆浓度一定时,假定泥浆中固体颗粒直径为10mm和20mm两种情况分别计算。通过分析计算结果发现:⑴泥泵的进口段和蜗壳内压力较高,没有空化发生,叶轮流道内靠近前盖板叶片背面进口稍后处,存在低压区,空化作用明显。⑵大流量工况下,泥泵叶轮流道内低压区的面积远大于设计流量和小流量工况,这说明泥泵在大流量工况下工作时更容易发生空化。⑶改变泥浆浓度,发现10%泥浆浓度时叶轮流道内低压区的面积小于20%泥浆浓度时的面积。⑷同一泥浆浓度时,固体颗粒直径为10mm时叶轮流道内低压区的面积小于直径为20mm时的面积。
论文最后总结了流量、泥浆浓度、泥浆中固体颗粒直径对泥泵空化性能的影响并提出改进设想和展望。
Dredging pump is widely used in the desilting of rivers and lakes as well as the dredging and maintaining of river course. However, cavitation may occurred by certain factors when the dredging pump is working. When this happens, noises and vibration produced by the pump will largely reduce the working efficiency. What’s worse, the pump could refuse working sometimes. Thus, searching for a way to improve the cavitation ability of the dredging pump is an important research area in fluid machinery.
With the rapid development of computer performance and computer fluid dynamics, numerical simulation has become an indispensable way in designing dredging pump and analyzing its inner flow field. Numerical simulation can largely cut down the work load of testing, moreover, it can help pre-estimate the immeasurable data in testing so as to contract work hours and improve the reliability as well as the economical efficiency.
This thesis is based on computer fluid dynamics and numerical simulation of the pump’s inner flow field, which is carried out by means of business application software of CFD: FLUENT. The author adopts three typical working conditions: designing discharge Q_1 = 5000 m~3/h, low discharge Q_2 = 3000 m~3/h and high discharge Q_3 = 7000 m~3/h. Meanwhile, two cases of mud concentration are adopted: 10% and 20%. Thus two cases are calculated respectively assuming that the diameter of the solid particle is 10mm or 20mm under a certain mud concentration. The following results can be found through analyzing the calculation: [1] The internal pressure of both the pump’s inlet section and the volute casing is relatively high without cavitations. However, an obvious cavitation is occurred by the low pressure range, which is reduced in the latter part of the back of the front flange’vane in the impeller chamber. [2] Under high-discharge working condition, the square area of low pressure range and cavity volume range in the pump’impeller vane is far more larger than that of designing discharge and low discharge, which illustrates that the dredging pump is easy to be cavitated under high-discharge working condition. [3] By changing the mud contraction, the author finds that, in case the mud contraction is 10%, the square area of low pressure range and the cavity volume range in the pump’impeller vane is less than that in the case of 20%. [4] Under the condition of the same mud contraction, the author also finds that, in case the diameter of selected particle is 10mm, the square area of low pressure range and the cavity volume range in the pump’impeller vane is less than that in the case of 20mm.Finally, the author makes a conclusion of the affect aroused by different factors towards the dredging pump’s performance and proposes revising plans and expectations.
随着计算机性能的不断提高以及计算流体力学技术的发展,数值模拟成为了设计泥泵和分析泥泵内部流场的一种重要方法。数值模拟可以大大的减少试验的工作量,并且能对试验中无法测量的数据进行预估,缩短工作时间,提高工作的可靠性和经济性。
本文以计算流体力学为基础,应用商业CFD软件FLUENT对泥泵流道内的空化流场进行了数值模拟。选取三种典型工况:设计流量Q_1 = 5000 m~3/h、小流量Q_2 = 3000 m~3/h以及大流量Q_3 = 7000 m~3/h。选择两种泥浆浓度:10%和20%,当泥浆浓度一定时,假定泥浆中固体颗粒直径为10mm和20mm两种情况分别计算。通过分析计算结果发现:⑴泥泵的进口段和蜗壳内压力较高,没有空化发生,叶轮流道内靠近前盖板叶片背面进口稍后处,存在低压区,空化作用明显。⑵大流量工况下,泥泵叶轮流道内低压区的面积远大于设计流量和小流量工况,这说明泥泵在大流量工况下工作时更容易发生空化。⑶改变泥浆浓度,发现10%泥浆浓度时叶轮流道内低压区的面积小于20%泥浆浓度时的面积。⑷同一泥浆浓度时,固体颗粒直径为10mm时叶轮流道内低压区的面积小于直径为20mm时的面积。
论文最后总结了流量、泥浆浓度、泥浆中固体颗粒直径对泥泵空化性能的影响并提出改进设想和展望。
Dredging pump is widely used in the desilting of rivers and lakes as well as the dredging and maintaining of river course. However, cavitation may occurred by certain factors when the dredging pump is working. When this happens, noises and vibration produced by the pump will largely reduce the working efficiency. What’s worse, the pump could refuse working sometimes. Thus, searching for a way to improve the cavitation ability of the dredging pump is an important research area in fluid machinery.
With the rapid development of computer performance and computer fluid dynamics, numerical simulation has become an indispensable way in designing dredging pump and analyzing its inner flow field. Numerical simulation can largely cut down the work load of testing, moreover, it can help pre-estimate the immeasurable data in testing so as to contract work hours and improve the reliability as well as the economical efficiency.
This thesis is based on computer fluid dynamics and numerical simulation of the pump’s inner flow field, which is carried out by means of business application software of CFD: FLUENT. The author adopts three typical working conditions: designing discharge Q_1 = 5000 m~3/h, low discharge Q_2 = 3000 m~3/h and high discharge Q_3 = 7000 m~3/h. Meanwhile, two cases of mud concentration are adopted: 10% and 20%. Thus two cases are calculated respectively assuming that the diameter of the solid particle is 10mm or 20mm under a certain mud concentration. The following results can be found through analyzing the calculation: [1] The internal pressure of both the pump’s inlet section and the volute casing is relatively high without cavitations. However, an obvious cavitation is occurred by the low pressure range, which is reduced in the latter part of the back of the front flange’vane in the impeller chamber. [2] Under high-discharge working condition, the square area of low pressure range and cavity volume range in the pump’impeller vane is far more larger than that of designing discharge and low discharge, which illustrates that the dredging pump is easy to be cavitated under high-discharge working condition. [3] By changing the mud contraction, the author finds that, in case the mud contraction is 10%, the square area of low pressure range and the cavity volume range in the pump’impeller vane is less than that in the case of 20%. [4] Under the condition of the same mud contraction, the author also finds that, in case the diameter of selected particle is 10mm, the square area of low pressure range and the cavity volume range in the pump’impeller vane is less than that in the case of 20mm.Finally, the author makes a conclusion of the affect aroused by different factors towards the dredging pump’s performance and proposes revising plans and expectations.
引文
[1]唐亚雄.国外挖泥船发展水平及动向[J].武汉理工大学学报,2006,(1):126-127页
[2]张文波,何希杰.挖泥船与泥泵技术发展概述[J] .通用机械,2008,8:20-24页
[3]何清华,徐海良,周友行.两相泵的汽蚀性能和吸泥高度[J].中南大学学报,2002,33(4):409-411页
[4]钟志锋.浅谈水泵空化的危害及防治[J].广东水利水电职业技术学院学报,2004,4(2):30-31页
[5]陈伟,韩季璋.泵的选型与应用——泵的空化[J].泵工程师,2008,(12):34-36页
[6]孙寿.水泵汽蚀及其防治[M].水利电力出版社,1989
[7]严敬,杨小林.国外水泵研究现状[J].排灌机械,2003,(21):2-3页
[8] Roussel O.An expert in industrial pump maintenance:the manufacturer [J].Word Pumps,1996(5);58-59 P
[9] Cudina M.Detection of cavitation phenomenon in a centrifugal pumpUsing audible sound[J].Mechanicalsystems and signal Processing,2003,17(6),1335-1347 P
[10] Alfayez L,Mba D,Dyson G.The application of acoustic emission for Detecting incipient cavitation and the best efficiency of a 60kw Centrifugal pump case study[J].NDT﹠E International,2005(38):354-358 P
[11]潘中永.泵诱导轮实验研究与CFD分析[D].镇江:江苏理工大学,2001
[12]袁建平,何志霞,袁寿其等.进口条件对组合叶轮性能的影响[J].江苏大学学报:自然科学版,2002,23(3):63-66页
[13]张人会,张学静,杨军虎.非设计工况下叶轮进口附近的流动及其控制[J].甘肃工业大学学报.2003,29(4):64-66页
[14]黄忠富,姜哲,赵斌娟等.利用小波分析诊断水泵初始阶段的汽蚀故障[J].排灌机械.2005,23(2):4-7页
[15]倪永燕,潘中永,李红等.出口压力波动特性在离心泵汽蚀检测中的应用[J].排灌机械.2006,24(5):40-43页
[16] R.T.柯乃普.空化与空蚀[M].水利电力出版社,1981
[17]高秋生.对液体空化机理的进一步探讨[J].河海大学学报.1999,27(5)
[18]夏维洪,沈惫如,孙景琴等.水中气核量测[J].水利学报.1993,4
[19] Oba R,Yasu S.Spatial cavitation-nuclei measurement by means of laser velocimeter[J]. Rep.Inst High Speed Mech,1978,310(38)
[20] Roland Leucher,Gerhard Rouve.Cavitation Research at the Institue of Hydraulic Engineering and Water Resources Managemeet[C]. Proceedings of the International Conference on Hydrodynamics,Wuxi,China 1994:263-271 P
[21]陆力,黄继汤.空泡在固液两相液体中靠近边壁附近溃灭的实验研究[J].水利学报.1991,(4):339-346页
[22]黄继汤,李靖.含沙静止液体中人工放电双空泡溃灭运动状态[J].水利学报.1992,(7):40-44页
[23]赵立强.固体颗粒对离心泵汽蚀性能的影响[J].排灌机械.1995,(4):7-8页
[24]李仁年,薛建欣.含沙水流时水泵汽蚀性能的分析研究[J].甘肃工业大学学报.1995,(3):40-44页
[25]王春龙,薛建欣.离心泵抽送含沙水时工作特性的试验研究[J].甘肃工业大学学报.1994,20(4):29-33页
[26]程则久.空化和磨蚀中临界含沙量的实验研究[J].水利水电技术.1990,(2):57-63页
[27]王勇,刘厚林.泵空化研究现状及展望[J].水泵技术.2008,(1):1-4页
[28]张维聚.含沙水流对泵的损坏及原因简析[J] .水泵技术.1990,(4),41-43页
[29]顾四行.抽黄水泵泥沙磨损及其对策[J].水泵技术.1994,(2):28-34页
[30]王勇,刘厚林.泵空化研究现状及展望[J].水泵技术.2008,(1):5-8.页
[31]王龙.结合全寿命维修理论讨论离心泵汽蚀的防护[J].通用机械.2008,(9):46-47页
[32] Yakhot V.,Orzag S.A,Renormalization Group Analysis of Turbulence:Base Theory J.Scient Comput.1986,(1):3-11 P
[33] J.D.ANDERSON,Compertuational Fluid Dynamics:The Basic with Application
[34]王福军.计算流体动力学分析——CFD软件原理与应用[M] .清华大学出版社,2007
[35] Singhal A.K,Athacale M.M,Li H Y,et al.Mathematical Basis and Validation of The Full Cavitation Model.ASME J.Fluids Eng,2002,124(9):617-624P
[36]高长银,马龙梅,涂志涛.Pro/ENGINEER野火4.0中文版模具设计技法与典型实例[M].电子工业出版社,2009
[37]吴玉林,刘树红,钱忠东.水力机械计算流体动力学[M].中国水利水电出版社,2007
[38]邓群贵,邓大华.基于Delaunay部分有限元网格节点和单元一体化生成方法[J].计算机辅助设计与图形学学报.1997,(9)60-64页
[39]韩占忠,王敬,兰小平.FLUENT流体工程仿真计算实例与应用[M] .北京理工大学出版社,2004
[2]张文波,何希杰.挖泥船与泥泵技术发展概述[J] .通用机械,2008,8:20-24页
[3]何清华,徐海良,周友行.两相泵的汽蚀性能和吸泥高度[J].中南大学学报,2002,33(4):409-411页
[4]钟志锋.浅谈水泵空化的危害及防治[J].广东水利水电职业技术学院学报,2004,4(2):30-31页
[5]陈伟,韩季璋.泵的选型与应用——泵的空化[J].泵工程师,2008,(12):34-36页
[6]孙寿.水泵汽蚀及其防治[M].水利电力出版社,1989
[7]严敬,杨小林.国外水泵研究现状[J].排灌机械,2003,(21):2-3页
[8] Roussel O.An expert in industrial pump maintenance:the manufacturer [J].Word Pumps,1996(5);58-59 P
[9] Cudina M.Detection of cavitation phenomenon in a centrifugal pumpUsing audible sound[J].Mechanicalsystems and signal Processing,2003,17(6),1335-1347 P
[10] Alfayez L,Mba D,Dyson G.The application of acoustic emission for Detecting incipient cavitation and the best efficiency of a 60kw Centrifugal pump case study[J].NDT﹠E International,2005(38):354-358 P
[11]潘中永.泵诱导轮实验研究与CFD分析[D].镇江:江苏理工大学,2001
[12]袁建平,何志霞,袁寿其等.进口条件对组合叶轮性能的影响[J].江苏大学学报:自然科学版,2002,23(3):63-66页
[13]张人会,张学静,杨军虎.非设计工况下叶轮进口附近的流动及其控制[J].甘肃工业大学学报.2003,29(4):64-66页
[14]黄忠富,姜哲,赵斌娟等.利用小波分析诊断水泵初始阶段的汽蚀故障[J].排灌机械.2005,23(2):4-7页
[15]倪永燕,潘中永,李红等.出口压力波动特性在离心泵汽蚀检测中的应用[J].排灌机械.2006,24(5):40-43页
[16] R.T.柯乃普.空化与空蚀[M].水利电力出版社,1981
[17]高秋生.对液体空化机理的进一步探讨[J].河海大学学报.1999,27(5)
[18]夏维洪,沈惫如,孙景琴等.水中气核量测[J].水利学报.1993,4
[19] Oba R,Yasu S.Spatial cavitation-nuclei measurement by means of laser velocimeter[J]. Rep.Inst High Speed Mech,1978,310(38)
[20] Roland Leucher,Gerhard Rouve.Cavitation Research at the Institue of Hydraulic Engineering and Water Resources Managemeet[C]. Proceedings of the International Conference on Hydrodynamics,Wuxi,China 1994:263-271 P
[21]陆力,黄继汤.空泡在固液两相液体中靠近边壁附近溃灭的实验研究[J].水利学报.1991,(4):339-346页
[22]黄继汤,李靖.含沙静止液体中人工放电双空泡溃灭运动状态[J].水利学报.1992,(7):40-44页
[23]赵立强.固体颗粒对离心泵汽蚀性能的影响[J].排灌机械.1995,(4):7-8页
[24]李仁年,薛建欣.含沙水流时水泵汽蚀性能的分析研究[J].甘肃工业大学学报.1995,(3):40-44页
[25]王春龙,薛建欣.离心泵抽送含沙水时工作特性的试验研究[J].甘肃工业大学学报.1994,20(4):29-33页
[26]程则久.空化和磨蚀中临界含沙量的实验研究[J].水利水电技术.1990,(2):57-63页
[27]王勇,刘厚林.泵空化研究现状及展望[J].水泵技术.2008,(1):1-4页
[28]张维聚.含沙水流对泵的损坏及原因简析[J] .水泵技术.1990,(4),41-43页
[29]顾四行.抽黄水泵泥沙磨损及其对策[J].水泵技术.1994,(2):28-34页
[30]王勇,刘厚林.泵空化研究现状及展望[J].水泵技术.2008,(1):5-8.页
[31]王龙.结合全寿命维修理论讨论离心泵汽蚀的防护[J].通用机械.2008,(9):46-47页
[32] Yakhot V.,Orzag S.A,Renormalization Group Analysis of Turbulence:Base Theory J.Scient Comput.1986,(1):3-11 P
[33] J.D.ANDERSON,Compertuational Fluid Dynamics:The Basic with Application
[34]王福军.计算流体动力学分析——CFD软件原理与应用[M] .清华大学出版社,2007
[35] Singhal A.K,Athacale M.M,Li H Y,et al.Mathematical Basis and Validation of The Full Cavitation Model.ASME J.Fluids Eng,2002,124(9):617-624P
[36]高长银,马龙梅,涂志涛.Pro/ENGINEER野火4.0中文版模具设计技法与典型实例[M].电子工业出版社,2009
[37]吴玉林,刘树红,钱忠东.水力机械计算流体动力学[M].中国水利水电出版社,2007
[38]邓群贵,邓大华.基于Delaunay部分有限元网格节点和单元一体化生成方法[J].计算机辅助设计与图形学学报.1997,(9)60-64页
[39]韩占忠,王敬,兰小平.FLUENT流体工程仿真计算实例与应用[M] .北京理工大学出版社,2004