水管流速表.doc

_管径(DN)流量 m3/h0.4m/s0.6m/s0.8m/s1.0m/s1.2m/s1.4m/s1.6m/s1.8m/s2.0m/s2.2m/s2.4m/s2.6m/s2.8m/s3.0m/s200.50.70.91.11.41.61.82.02.32.52.72.93.23.4250.71.11.41.82.12.52.83.23.53.94.24.64.95.3321.21.72.32.93.54.14.65.25.86.46.97.58.18.7401.82.73.64.55.46.37.28.19.010.010.911.812.713.6502.84.25.77.18.59.911.312.714.115.617.018.419.821.2654.87.29.611.914.316.719.121.523.926.328.731.133.435.8807.210.914.518.121.725.329.032.636.239.843.447.050.754.310011.317.022.628.333.939.645.250.956.562.267.973.579.284.812517.726.535.344.253.061.970.779.588.497.2106.0114.9123.7132.515025.438.250.963.676.389.1101.8114.5127.2140.0152.7165.4178.1190.920045.267.990.5113.1135.7158.3181.0203.6226.2248.8271.4294.1316.7339.325070.7106.0141.4176.7212.1247.4282.7318.1353.4388.8424.1459.5494.8530.1300101.8152.7203.6254.5305.4356.3407.1458.0508.9559.8610.7661.6712.5763.4350138.5207.8277.1346.4415.6484.9554.2623.4692.7762.0831.3900.5969.81039.1400181.0271.4361.9452.4542.9633.3723.8814.3904.8995.31085.71176.21266.71357.2450229.0343.5458.0572.6687.1801.6916.11030.61145.11259.61374.11488.61603.21717.7500282.7424.1565.5706.9848.2989.61131.01272.31413.71555.11696.51837.81979.22120.6, 600407.1610.7814.31017.91221.41425.01628.61832.22035.72239.32442.92646.52850.03053.6什么叫给水管道的经济流速？它是如何确定的？根据流量、流速与管径之间关系公式得知，当管道流量不变时，如选择管径较大时，流速则减小，此时水在管道内的流动阻力也会减少。流速低水头损失小，选择水泵扬程较低可节省初投资及运行费用。相反，如选择管径较小，流量不变时会加大水在管道内的阻力，此时需提高水泵的扬程而加大运行成本。为了使投资和运行费用更合理化，规范规定给水速度在允许范围内选择一最佳给水流速，这一最佳给水流速称为经济流速管内水的阻力实际上受着管道材质、流速、水量、管径、输送长度、管道上各种管件、阀门、安装的高程等多种因素影响。确定一个合理的经济流速是很困难的，所以人们通过多次试验及长期的实践，总结测定较为合理的经济流速作为选择使用，经济流速可参考图片:2010052106.JPG 大流量长距离管道内某些流体的常用流速范围见表1-1。 表1-1 某些流体在管道中的常用流速范围 流体及其流动类别 流速范围/（m/s）流体及其流动类别 流速范围/（m/s）自来水（3105Pa）11.5 高压空气1525 水及低粘度液体（1105Pa1106Pa）1.53.0 一般气体（常压）1020 高粘度液体 0.51.0 鼓风机吸入管 1020 工业供水（8105Pa以下）1.53.0 鼓风机排出管1520 锅炉供水（8105Pa以下）3.0 离心泵吸入管（水类液体）1.52.0 饱和蒸汽2040离心泵排出管（水类液体）2.53.0过热蒸汽 3050往复泵吸入管（水类液体）0.751.0蛇管、螺旋管内的冷却水 1.0 往复泵排出管（水类液体）1.02.0低压空气 1215液体自流速度（冷凝水等）0.5