1、轴流泵设计步骤轴流泵设计数据 1、设计参数: 流量 Q 1000( m/h ) 扬程 H 4.5 (m) 转速 n 1450 ( r/min ) 效率 85 汽蚀比转速C1000 2、结构形式: 采用60出水弯管 3、 底板至叶轮中心距离:1m轴流泵水力设计一、叶轮的水力设计(一)结构参数的选择1确定轮毂比 根据轮毂比与比转速的关系表,取14001000700500d0.350.400.400.350.480.550.550.602叶轮直径D 叶轮直径一般根据轴面速度来确定,为了得到最优的影片安放角,叶轮进口前的轴面速度,采用C.C.鲁德涅夫推荐公式来确定:根据液流的连续性条件,不考虑排挤,则
2、叶轮区域内的轴面速度为 取,则根据轮毂比及给定的参数,叶轮直径即可求出。则 取 D=272mm 即 3确定叶片数Z 叶片数通常按选取50070010001400Z5645343为了更易于调节动平衡,取Z=44确定叶栅稠密度Z=4,叶轮外缘的叶栅稠密度推荐为,同时,适当减小外缘的,增加轮毂侧的,以减小内外侧翼型的长度差,均衡叶片出口的扬程。所以,轮毂和轮缘之间各截面的按直线规律变化,其值为 取,则4确定叶片翼型的厚度:通常轮毂截面的相对厚度为 (1015)%轮缘截面的厚度按工艺条件确定,通常轮缘截面的相对厚度 (25)%从轮毂到轮缘其厚度按直线规律变化。(二) 选定截面及计算1确定计算截面通常选
3、取五个彼此等距离的计算流面,由于本设计要求为为半调节式轴流料浆泵,考虑到叶片的调节,轮毂和轮缘需作成球面。 各计算流面的半径可按下式确定: 截面D取值:122,160,198,236,2722确定轴面速度和速度环量(1)确定轴面速度 取 即 (2)确定速度环量 3升力法设计计算选定截面计算表格设计公式截面截面截面截面截面112216029823627229.262512.147515.032517.917620.650736.0286.0286.0286.0286.02845.31084.04953.27232.74542.381250.91240.59550.45000.36430.3098
4、642.377330.773824.227720.016717.213071111180.99980.99980.99980.99980.999890.68680.52660.42620.35860.31261095.8186125.6637155.5088185.3540213.628311由图10100.960.910.850.790.7312 l91.9859114.3540132.1825146.4297155.948713 l取整921141321461561479.9906138.8069215.7990310.0705415.0148151.16520.66780.42890.2
5、9760.2213161.21380.73380.50460.37670.3032170.91.121.371.51.55181.348670.655180.368320.251130.195611911.9611.410.5610.229.3620 选择翼型(NACA)4413441044084407440621164-1-2-32258.3834.7723.2318.0214.21231.11.10.9-1.20.94计算泵的汽蚀比转速C 知道设计流量Q和轴流泵的转速n,根据GB/T 13006-91,查取临界汽蚀余量,计算泵的汽蚀比转速C:,查得符合设计要求。计算各截面翼型厚度坐标(1)
6、截面:NACA4413l=9211.96比例0.919x01.152.304.596.899.1913.7818.3722.96h02.433.354.665.646.447.678.529.10b0-1.42-1.96-2.53-2.81-2.97-3.04-2.95-2.67x27.5636.7445.9355.1264.3073.4982.6787.2792h9.429.448.887.846.434.692.601.410b-2.54-2.09-1.69-1.27-0.87-0.55-0.31-0.210翼型如图: (2)截面:NACA4410l=11411.4比例1.138x01.4
7、22.845.698.5311.3817.0722.7528.44h02.303.274.635.716.567.938.909.57b0-1.44-1.79-2.20-2.37-2.39-2.28-2.03-1.73x34.1345.5156.8968.2679.6491.02102.40108.08114h9.9710.029.458.406.915.042.791.510b-1.43-0.96-0.59-0.27-0.060.060.020.050翼型如图:(3)截面:NACA4408l=13210.56比例1.318x01.653.36.599.8913.1819.7826.3732.
8、96h02.153.114.525.636.548.009.049.76b0-1.21-1.54-1.82-1.85-1.79-1.46-1.08-0.69x39.5552.7365.9279.1092.28105.47118.65125.24132h10.229.709.808.717.195.272.901.570b-0.340.180.500.700.740.620.360.130翼型如图:(4)截面:NACA4407l=14610.22比例1.458x01.823.647.2910.9314.5821.8729.1636.45h02.13.094.535.696.638.189.301
9、0.07b0-1.14-1.43-1.60-1.55-1.36-0.99-0.51-0.04x43.7458.3272.9087.48102.05116.63131.21138.50146h10.5710.7610.199.087.515.513.031.630b0.350.901.181.311.251.010.550.250翼型如图:(5)截面:NACA4406l=1569.36比例1.555x01.943.897.7711.6615.5523.3231.0938.87h01.942.924.345.496.458.019.179.98b0-1.00-1.23-1.27-1.14-0.93
10、-0.390.190.72x46.6462.1977.7493.29108.84124.39139.93147.71156h10.5110.7310.189.107.545.543.051.630b1.151.711.931.971.801.410.760.370翼型如图:5叶轮绘型(1)画翼型展开图(2)确定叶片旋转轴线位置: 旋转轴线通常取离翼弦进口为(0.30.4)l处,而且一般和翼型最大厚度位置一致。另外,旋转中心一般通过翼型的骨线,也可以偏离骨线,但是,其纵向位置应当有规律变化,以保证叶片表面的光滑。(3)作叶片轴面投影图,(4)坐平面投影图和木模截线图二、导叶的水力设计(一) 导叶
11、结构参数的选择 1 确定导叶体的扩散角 一般导叶体的扩散角为,取。2 导叶进口边一般和叶轮出口平行,其间距为e=(0.050.1)D,即 e=13.627.2mm 取 3 叶片数一般取Z=510片,低比转速取大值,本设计为比转速的轴流清水泵,故取叶片数Z=7。4 弯管(管径为)通常是等截面的,因此,与之相联的扩散管出口直径()也应该与弯管相同,为标准直径。 故 1 导叶的设计与计算(见下表):r0.0610.080.0990.1180.136D122160198236272Vm6.0286.0286.0286.0286.028Vu5.31084.04953.27232.74542.38210.88420.91820.93690.94860.95621.28
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