《给水管网设计案例探析》3100字

给水管网设计案例分析综述1.1.供水要求（1）水质要求广西自治区LB市HX区生活饮用水水质标准要求达到《生活饮用水卫生标准》（GB5749—2006），并且管网末梢仍保留一定的余氯。（2）水量要求给水管网按LB市HX区设计供水规模的最高日最高时进行计算，LB市HX区设计供水规模为4万立方米每日，时变化系数为1.4；管网发生事故时，供水量应满足最高日最高时的70%；满足管网最不利点消防时的用水量。（3）水压要求管网最不利水压要求达到28米，用户端龙头压力不大于40米，超过情况下应采取减压措施。消防时，发生火灾点管网水压要求达到10米。1.2管网设计计算1.2.1最高日最高时用水量计算由任务书给出广西自治区LB市HX区设计供水规模Q=40000(mQ1.2.2消防用水量计算LB市HX区人口约37万，则同一时间内的火灾起数为n=2起，一起火灾灭火设计流量为QxQ1.2.3事故用水量计算Q1.3管网定线1.3.1给水管网的布置给水管网的布置应满足以下要求:（1）给水管网应按照城市平面规划布置，要考虑到给水管网分期建设的可能，并为城市的后续发展预留空间。（2）管线需遍布整个供水区域，保证用户有足够的水量和合适的水压。（3）管网的布置必须保证供水的安全可靠，当管线发生事故时需保障断水范围应尽可能小；火灾时，要保证有足够的水量的水压。（4）力求以最短的距离敷设管线，以降低管网的造价和供水能量费用。（5）给水管网应采用树状网和环状网混合布置。1.3.2给水管网定线城市给水管网定线仅限于干管和连接管，干管之间的间距一般为500~800米，除特殊情况下，最长计算管道不可超过1000米，连接管之间的间距一般采用800~1000米。根据城市路网图，给出两种给水管网定线方案，见图水初-08（管网定线图一）和水初-09（管网定线图二）。由于管网定线图二有部分管线长度远低于给水管网定线要求，故给水管网定线选择水初-08（管网定线图一）的定线方案。1.4管网水力计算1.4.1节点流量计算本设计为方便计算比流量qs（1）比流量qq式中qs——比流量，L/（s·m）Q——管网最高时用水量，L/s；∑q——大用户集中用水量总和，L/s；∑l——管线计算总长度，m。（2）沿线流量qq式中ql——沿线流量，L/sl——该管段沿线长度，m。（3）节点流量qq式中qi——节点流量，L/s即任一节点i的节点流量qi等于与该节点相连各管段的沿线流量q1.4.2事故时节点流量为保证管网供水安全，应断开流量最大的管段进行事故管网计算，事故时节点流量均以最高时节点流量的70%计算，即q1.4.3消防时节点流量为保证消防时各点水量和水压满足要求，最不利的和次不利点节点流量为q1.4.4管网水力要求（1）管段界限流量本设计LB市HX区经济因素取f=0.8，为减小管网的年费用，该管网界限流量表如下。界限流量表表4-1管径（mm）界限流量（L/s）当地经济因素为f=0.8时的管段流量（L/s）100＜9.00＜9.691509.00~15.009.69~16.1620015.00~28.5016.16~30.7025028.50~45.0030.70~48.4730045.00~68.0048.47~73.2535068.00~96.0073.25~103.4140096.00~130.00103．41~140.04450130.00~168.00140.04~180.97500168.00~237.00180.97~255.30600237.00~355.00255.30~382.41700355.00~490.00382.41~527.84800490.00~685.00527.84~737.89900685.00~822.00737.89~885.471000822.00~1120.00885.47~1206.48（2）流速要求为了防止管网因为水锤作用发生事故，所以管段的最大流速不应超过2.5m/s；同时为了避免水中悬浮物在管网中沉降，故管段的最低流速一般不得小于0.6m/s。（3）阻力系数为防止管网水头损失过大，增大水泵扬程，使管网运行费用增加，故一般规定管径大于等于400mm的管段1000i宜小于3，管径小于400mm的管段1000i宜小于5。1.4.5管网水力计算结果（1）各工况下的节点压力与自由水头各工况下的节点压力与自由水头表4-2节点编号地面标高

（m）最高时事故时消防时节点流量

（L/s）总水头

（m）自由水头

（m）节点流量

（L/s）总水头

（m）自由水头

（m）节点流量

（L/s）总水头

（m）自由水头

（m）187.4015.08121.4634.0510.56126.5439.1415.08109.4822.08290.3320.49123.9133.5714.34128.8338.5020.49113.2822.95390.6919.35125.2334.5413.54130.0339.3419.35115.3124.62489.7720.85125.9736.2014.59130.9441.1720.85116.7827.01588.7720.98126.8738.1014.68132.0443.2720.98118.5529.78688.3520.97125.9337.5814.68130.7042.3520.97117.4929.14787.8214.62123.6235.8010.24128.8441.0314.62115.0927.27889.0513.95119.8130.779.76122.6533.6013.95104.0915.04991.2618.99120.9729.7113.29122.6531.3918.99104.1712.911094.3025.48122.3028.0017.84122.6528.35100.48104.3010.001194.1921.95123.4329.2415.36122.1928.0096.95105.6711.481293.4636.50125.1931.7325.55121.8228.3736.50115.7722.311390.5435.64123.6233.0824.94124.8434.3035.64114.6524.111487.9621.36120.0932.1314.95124.4936.5321.36111.2823.321585.1625.01121.6436.4817.51127.1642.0025.01113.0127.861687.5829.26119.9832.4020.48120.5532.9729.26104.5616.981791.9840.37123.6931.7128.26121.5529.5740.37113.9021.921884.4038.05121.5137.1226.64122.9338.5438.05112.2727.871985.2820.29117.6832.4014.21122.1836.9020.29108.6523.372086.5819.45118.1631.5813.61123.2636.6919.45109.2522.672186.6127.79119.4932.8819.45125.4238.8127.79110.7724.152285.2416.33116.1130.8811.43122.6737.4416.33107.2121.972385.963.98117.9531.992.78119.4833.523.98104.2518.292486.9725.80118.2431.2718.06119.6332.6625.80104.5417.572586.0628.30120.8334.7719.81120.9434.8828.30110.5824.522681.3926.23120.0938.7118.36121.8140.4226.23110.5329.142783.5419.61116.3632.8213.73121.0937.5519.61107.1823.652883.9116.63115.3231.4111.64120.8536.9416.63106.2222.312982.214.86114.8032.603.40120.5838.384.86105.7023.49合计648.15453.69798.17（2）各工况下水泵参数各工况下水泵参数表4-3工况净水厂总水头需要流量（L/s）需要流量（m3/h）最高时126.99648.152333.33事故时132.10453.701633.33消防时118.72798.152873.33注：净水厂总水头是以净水厂地面高程87.00m计。（3）最高时管段水力最高时管段水力表表4-4管段编号管长

（m）管径

（mm）Ch流量

（L/s）流速

（m/s）1000i水头损失

（m）0-543.58600110324.071.152.640.120-543.58600110324.071.152.640.1210-11509.0725011029.590.602.231.1410-16800.7020011018.940.602.892.3111-12940.0730011043.440.611.871.761-2669.1620011021.490.683.662.4512-13920.5630011041.310.581.701.5612-171259.56500110130.650.671.191.5013-14914.3020011022.120.703.863.5313-181227.5440011088.450.701.722.1114-15701.7620011016.340.522.201.5414-20806.2520011017.100.542.401.9415-211266.5235011061.810.641.702.1516-17990.2520011021.760.693.743.7016-241527.0820011011.430.361.141.7417-181327.0820011013.920.441.642.1817-251001.2030011054.600.772.862.861-81041.381501106.400.361.581.6518-19933.5520011022.860.734.103.8318-26827.1330011041.460.591.711.4119-20475.9320011010.660.341.000.4819-27891.8320011013.220.421.491.3320-21923.2620011013.000.411.441.3321-22961.3120011021.020.673.513.3722-28890.041501104.690.270.890.792-3539.5230011050.420.712.461.3323-24451.181501103.980.230.650.2924-25947.5120011018.340.582.732.5925-261260.222001107.960.250.580.7326-27887.0720011023.190.744.213.7327-28445.1620011016.800.532.321.0328-29550.781501104.860.270.950.522-91114.581501108.440.482.632.933-101081.2525011032.920.672.722.943-4573.26450110102.680.651.280.734-111039.811501108.100.462.442.544-5751.33500110131.630.671.210.915-121018.62600110251.890.891.661.695-6609.05600110243.650.861.560.956-13978.74400110104.900.832.362.316-7790.44400110117.780.942.922.317-15867.71400110103.150.822.281.988-9540.111501107.540.432.141.169-10498.7520011018.090.582.661.33（4）事故时管段平差结果事故时管段平差结果表4-5管段编号管长

（m）管径

（mm）Ch流量

（L/s）流速

（m/s）1000i水头损失

（m）0-543.58600110226.850.801.360.060-543.58600110226.850.801.360.0610-11509.0725011018.150.370.900.4610-16800.7020011017.920.572.612.0911-12940.0730011018.600.260.390.371-2669.1620011020.750.663.432.3012-13920.5630011058.780.833.273.0112-171259.5650011051.830.260.220.2813-14914.302001106.350.200.380.3513-181227.5440011083.630.671.551.9014-15701.7620011021.960.703.812.6714-20806.2520011013.350.431.521.2315-211266.5235011055.120.571.371.7416-17990.2520011010.700.341.011.0016-241527.082001108.140.260.610.9317-181327.0820011010.910.351.041.3817-251001.2030011023.780.340.610.611-81041.3815011010.190.583.733.8818-19933.552001109.490.300.810.7618-26827.1330011036.600.521.361.1219-20475.9320011016.610.532.271.0819-27891.8320011011.890.381.221.0920-21923.2620011016.870.542.342.1621-22961.3120011018.800.602.862.7522-28890.041501107.370.422.051.822-3539.5230011047.720.682.221.2023-24451.181501102.780.160.340.1524-25947.5120011012.700.401.381.3125-261260.222001108.730.280.690.8726-27887.072001109.510.300.810.7227-28445.162001107.670.240.540.2428-29550.781501103.400.190.490.272-91114.5815011012.630.715.556.193-101081.2525011054.141.106.837.383-4573.26450110115.400.731.580.914-111039.8115011015.810.898.428.764-5751.33500110145.810.741.461.105-6609.05600110293.211.042.191.336-13978.74400110173.711.386.005.876-7790.44400110104.820.832.351.867-15867.7140011094.580.751.951.698-9540.111501100.430.020.010.019-10498.752001100.230.010.000.00（5）消防时管段平差结果消防时管段平差结果表4-6管段编号管长

（m）管径

（mm）Ch流量

（L/s）流速

（m/s）1000i水头损失

（m）0-543.58600110399.071.413.880.170-543.58600110399.071.413.880.1710-11509.0725011032.740.672.691.3710-16800.702001105.790.180.320.2611-12940.07300110111.701.5810.7510.111-2669.1620011027.250.875.683.8012-13920.5630011034.410.491.211.1112-171259.56500110147.250.751.491.8813-14914.3020011021.570.693.693.3713-181227.5440011094.540.751.942.3814-15701.7620011017.370.552.471.7314-20806.2520011017.580.562.522.0315-211266.5235011063.360.661.772.2416-17990.2520011035.831.149.439.3416-241527.082001100.780.020.010.0217-181327.0820011011.910.381.231.6317-251001.2030011059.140.843.313.311-81041.3815011012.170.695.185.3918-19933.5520011022.1