异速复合叶轮的混合性能

发布时间：2018-02-27 01:14

本文关键词： 异速复合叶轮混合性能涡轮-斜叶桨内外螺带　出处：《华东理工大学》2017年硕士论文　论文类型：学位论文

【摘要】：本文设计了异速涡轮-斜叶桨和异速内外螺带两种复合叶轮,并用实验的方法对其混合性能进行了考察,重点考察了功率、混合时间和流型,得到了二者的混合的基本规律。研究结果表明:异速涡轮-斜叶复合桨叶的功率是涡轮桨和斜叶桨单独转动时功率的加和。转速比对各桨叶的功耗影响显著,下排流工况时,斜叶桨功率占整个复合桨叶的功率比例由转速比RN=1时的26%增加至RN=4时的95.4%,上排流工况时其比例由23.8%增加至94.5%,当RN=10时,两种工况下斜叶桨的功耗高达99%以上。异速涡轮-斜叶复合桨输入功率相同时,转速比增大混合时间降低,混合效果提升。下排流操作中,当 RN=1,NPBT=200 rpm,NRT=200 rpm 时与 RN=3,NPBT=300 rpm,NRT=100 rpm时相比,两种情况下异速复合桨叶输入相同的功率,RN=3工况下的混合时间比RN=1时的混合时间减少14.3%。同样地,RN=10,NPBT=500 rpm,NRT=50 rpm时的混合时间比RN=1,NPBT=300 rpm,NRT=300 rpm的混合时间减少17.8%。上排流操作中,两种转速比下输入相同的功率,混合时间分别降低了 13.9和21.5%。观察流型发现,增大某一个桨叶的转速可以减小两层桨叶中间和釜底边缘的低速区域。对于异速内外螺带,同向转动时,内螺带和外螺带的功率都比其单独转动时的功率要低;反向转动时,外螺带功率比外螺带单独转动时高,而内螺带功率增加不明显。内外螺带的转速比对功率影响显著,随着转速比的增大,内螺带功率不断提升,同向转动时内螺带的功率占整个复合叶轮的功率由RN=0.5时6.4%逐渐增加至RN=5时的91%,反向转动时其比例从9.5%增加至83%。异速内外螺带同向转动时的混合时间要小于反向转动时的混合时间。观察分析流型发现,同向转时釜内的循环比反向旋转时的好。
[Abstract]:In this paper, two kinds of composite impellers with different speed turbine, oblique blade impeller and different speed inner and outer screw belt are designed. The mixing performance of the impellers is investigated by the method of experiment, especially the power, mixing time and flow pattern. The results show that the power of the compound blade is the sum of the power when the propeller and the propeller are rotated separately. The ratio of rotating speed has a significant effect on the power consumption of each blade. The power ratio of the oblique blade to the whole composite blade increased from 26% to 95.410 when RN = 1:00, and increased from 23.8% to 94.5g in the upper discharge condition, when RN = 10:00, The power consumption of inclined blade propeller is up to more than 99% under two working conditions. When the input power of different speed turbine-oblique blade composite propeller is the same, the speed ratio increases and the mixing time decreases, and the mixing effect is improved. In down-flow operation, when RNNN 1N NPBTT 200rpmN NRTT 200 rpm is compared with RNM3NPBT300rpmNRT100 rpm, In both cases, the mixing time at the same power input at the same power / RN3 is 14.3mm lower than the mixing time at 1:00. Similarly, the mixing time at RNN10NPBTT 500rpmNRTT / 50 rpm is less than that at RNN1NP300rpNRT300 rpm. In the upflow operation, the mixing time is 17.80.In the upper drainage operation, the mixing time of the RNN10NNNRT300 rpm is reduced by 17.8% compared with the RNN1NP300rpNRT300 rpm. The mixing time is reduced by 13.9 and 21.5.The observation of flow pattern shows that increasing the rotational speed of a certain blade can reduce the low speed region between the two blades and the edge of the bottom of the kettle. When rotating in the same direction, the power of the inner and outer snails is lower than that of the inner and outer snails, and the power of the outer snails is higher than that of the outer snails in the reverse rotation. But the power increase of inner snail band is not obvious. The speed ratio of internal and external snails is more significant than that of power, and with the increase of rotational speed ratio, the power of inner snail band increases continuously. The power of the inner spiral belt gradually increased from 6.4% at RN = 0.5 to 91g at 5:00, and the ratio increased from 9.5% to 83 when rotating in the reverse direction. The mixing time of the inner spiral belt in the same direction was shorter than that in the reverse rotation. Dynamic mixing time. Observation and analysis of flow patterns, The circulation in the kettle is better than that in the reverse rotation.
【学位授予单位】：华东理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TQ051.71

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