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ID:9127592
大小:59.00 KB
页数:7页
时间:2018-04-18
《不同转速下液体透平的性能研究》由会员上传分享,免费在线阅读,更多相关内容在应用文档-天天文库。
1、不同转速下液体透平的性能研究苗森春杨军虎王晓晖史广泰兰州理工大学甘肃省流体机械及系统重点实验室流体及动力机械教育部重点实验值(西华大学)为丫明确转速对离心泵作液力透平的性能影响,本文棊于Navicr-Stokcs方程和标准的湍流模型,采用SIMPLE算法,应用商业软件ANSYS-FLUENT对转速分别为750,1000,1500,2000和2900r/min下的液力透平进行了数值模拟,得到了不同转速下液力透平的外特性曲线。结果表明:对于所研究模型而言,随着转速的不断增大,液力透平最优效率点的效率呈增
2、大趋势,但增加梯度相对较小;最优效率点的流量与转速呈线性增加的趋势;扬程与功率均随着转速的增加而增大,其中扬程在小流量工况时增加梯度较大,而在大流量工况时增加的梯度相对较小;功率的变化规律恰好与扬程变化规律相反,即功率随着转速的增大在小流量工况时增大梯度较小,而在大流量工况时急剧上升。另外,根据不同转速下液力透平的性能特点得出:在小流量工况时,降速对提高液力透平的效率有显著作用,与之对应,在大流量工况运行时,增加转速也可以提高液力透平的能量回收能力,但前提是需要保证结构强度满足要求。总之,该研宂结果
3、可对液力透平的经济运行提供部分参考。关键词:转速;泵作液力透平;数值模拟;离心泵;梯度;基金:国家&然科学基金资助项目(51569013)EffectofBladeNumberonPerformanceofPumpasTurbineMIAOSen-chunYANGJun_huWangXiao-huiSHIGuang-taiLanzhouUniversityofTechnology;KeyLaboratoryofFluidandPowerMachinery,MinistryofEducation(Xi
4、huaUniversity);Abstract:Inordertocleartheinfluenceofthespeedonperformanceofpumpasturbine,basedonNavier-Stokesequation,k-eturbulencemodelandSIMPLEalgorithm,thenumericalsimulationusingcommercialsoftwareANSYS-FLUENTforthepumpasturbineatdifferentspeeds(750
5、,1000,1500,2000and2900r/minwascarriedout.Accordingtotheresultofnumericalsimulationunderdifferentspeeds,theexternalcharacteristiccurveandInternalflowcharacteristicsofpumpasturbinewereobtainedofpumpasturbinerespective!y.Theresultsshowthat:Fortheresearchm
6、odel,withtheincreasingofthespeed,theefficiencyoftheoptimalefficiencyofthepumpasturbineisgraduallyincreasing,butthegradientisrelativelysmall.Theflowrateandrotatingspeedoftheoptimalefficiencypointisbasicallylinearincreasingtrend.Boththeheadandthepowerinc
7、reasewiththeincreaseoftherotatingspeed.Theheadinsmallflowconditionstoincreasethegradientislarger,andalargeflowconditiontoincreasethegradientisrelativelysmall.Thechangetrendofpowerisoppositetothechangelawofthehead,i.e.withtheincreaseofthepower,thegradie
8、ntisrelativelysmallwhenthesmallflowrateincreases,andthepowerofthelargeflowrateincreasessharplywiththeincreaseofthespeed.Thefartherawayfromtheoptimalworkingcondition,themoreseriousthedegreeofdeclineinefficiency.Accordingtotheperformancec
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