虹吸雨水计算书计算原理参考《建筑与小区雨水利用工程技术规范》(GB50400-2006)一、基本参数:管材:HDPE温度:10℃二、基本计算公式:1、暴雨强度公式:nbtPCAq)()lg1(167++=式中:q--降雨强度,(L/s·ha、L/s·hm2、L/s·104m2)t--降雨历时(min)P--设计重现期(年)A、b、C、n--当地降雨参数2、雨水设计流量公式:qFkQlψ=式中:Q--雨水设计流量(L/s)q--降雨强度,(L/s·ha、L/s·hm2、L/s·104m2)ψ--径流系数。F--汇水面积(hm2)1hm2=10000平方米gvdlhf2λ2=式中:hf--管道沿程阻力损失(m);1米=10kPaλ--管道沿程阻力损失系数,按下式计算l--管道长度(m)d--管道计算内径(m)v--管内流速(m/s)g--重力加速度(m/s2)取9.81λΔλRe51.27.3lg21d式中:△--管壁绝对粗糙度(mm),由管材生产厂提供Re--雷诺数5、局部阻力损失:∑25xjvTh=式中:hj--局部阻力损失(mbar)1mbar=100pa=0.1kPaT--局部阻力系数Vx--管道某一x断面处流速(m/s)6、总阻力损失jfhhh+=总7、管道某一x断面处的压力:2251.98xxxxZvhP式中:Px--管道某一x断面处的压力(mbar)1mbar=100pa=0.1kPahx--雨水斗顶面至计算断面的高度差(m)vx--管道某一x断面处流速(m/s)∑Zx-2--断面处对应最远雨水斗至计算断面的总阻力损失之和(mbar)8、压力余量计算公式:ZvHPr2151.98式中:△Pr--压力余量(mbar)1mbar=100pa=0.1kPaH--雨水斗顶面与排水管出口的几何高差(m)V1--排水管出口的管道流速(m/s)∑Z--最远雨水斗至排水口处的总阻力损失之和(mbar)三、虹吸雨水水力计算表:管段名称流量(L/s)管长(m)管径(mm)流速(m/s)沿程阻力损失(kPa)局部阻力系数局部阻力损失(kPa)总阻力损失(kPa)Σ总阻力损失(kPa)高差(m)压力(kPa)124.261.61103.011.6483.616.30917.95717.9571.655-6.252224.2611252.330.5310.61.6282.15920.1171.655-6.594324.26181601.4222.6920.90.913.60123.7181.655-8.493448.52182001.8223.30.91.4944.79428.5121.655-13.271572.78182002.7337.280.93.36110.64139.1531.655-24.493697.04182003.6438.8040.94.97413.77852.9311.655-43.5197121.3182004.55419.8770.916.80136.67889.6091.655-76.4648145.568.62503.4964.2810.84.8889.16998.7781.655-81.3729145.5662503.4962.987002.987101.7657.655-25.49910145.5618.41608.5392.7291.243.658136.387238.15226.055-11.65411145.5631608.5315.1190015.119253.27126.05515.87512145.5623151.7020.3781.82.6072.985256.25626.05520.2951324.261.61103.011.6483.616.30917.95717.9571.655-6.2521424.2611252.330.5311.64.6135.14423.1011.655-9.5791524.261.6904.4844.6383.636.18840.82640.8261.655-34.6421624.2611103.011.031.67.2498.27949.1051.655-37.8531724.261.6904.4844.6383.636.18840.82640.8261.655-34.6421824.2611103.011.031.67.2498.27949.1051.655-37.8531924.261.6756.47812.1153.675.54787.66287.6621.655-92.4122024.2611103.011.031.67.2498.27995.9411.655-84.6892124.261.6756.47812.115483.94296.05696.0561.655-100.8062224.261756.4787.5761.633.57641.152137.2081.655-144.0573、流速2π4dQv=式中:V--流速(m/s)Q--管段流量(L/s)d--管道的计算内径(m)4、沿程阻力损失:四、计算结果:管道最大负压值:-81.37kPa压力余量:20.3kPa