《給水管網(wǎng)設(shè)計案例探析》3100字

給水管網(wǎng)設(shè)計案例分析綜述1.1.供水要求（1）水質(zhì)要求廣西自治區(qū)LB市HX區(qū)生活飲用水水質(zhì)標準要求達到《生活飲用水衛(wèi)生標準》（GB5749—2006），并且管網(wǎng)末梢仍保留一定的余氯。（2）水量要求給水管網(wǎng)按LB市HX區(qū)設(shè)計供水規(guī)模的最高日最高時進行計算，LB市HX區(qū)設(shè)計供水規(guī)模為4萬立方米每日，時變化系數(shù)為1.4；管網(wǎng)發(fā)生事故時，供水量應(yīng)滿足最高日最高時的70%；滿足管網(wǎng)最不利點消防時的用水量。（3）水壓要求管網(wǎng)最不利水壓要求達到28米，用戶端龍頭壓力不大于40米，超過情況下應(yīng)采取減壓措施。消防時，發(fā)生火災(zāi)點管網(wǎng)水壓要求達到10米。1.2管網(wǎng)設(shè)計計算1.2.1最高日最高時用水量計算由任務(wù)書給出廣西自治區(qū)LB市HX區(qū)設(shè)計供水規(guī)模Q=40000(mQ1.2.2消防用水量計算LB市HX區(qū)人口約37萬，則同一時間內(nèi)的火災(zāi)起數(shù)為n=2起，一起火災(zāi)滅火設(shè)計流量為QxQ1.2.3事故用水量計算Q1.3管網(wǎng)定線1.3.1給水管網(wǎng)的布置給水管網(wǎng)的布置應(yīng)滿足以下要求:（1）給水管網(wǎng)應(yīng)按照城市平面規(guī)劃布置，要考慮到給水管網(wǎng)分期建設(shè)的可能，并為城市的后續(xù)發(fā)展預(yù)留空間。（2）管線需遍布整個供水區(qū)域，保證用戶有足夠的水量和合適的水壓。（3）管網(wǎng)的布置必須保證供水的安全可靠，當管線發(fā)生事故時需保障斷水范圍應(yīng)盡可能??；火災(zāi)時，要保證有足夠的水量的水壓。（4）力求以最短的距離敷設(shè)管線，以降低管網(wǎng)的造價和供水能量費用。（5）給水管網(wǎng)應(yīng)采用樹狀網(wǎng)和環(huán)狀網(wǎng)混合布置。1.3.2給水管網(wǎng)定線城市給水管網(wǎng)定線僅限于干管和連接管，干管之間的間距一般為500~800米，除特殊情況下，最長計算管道不可超過1000米，連接管之間的間距一般采用800~1000米。根據(jù)城市路網(wǎng)圖，給出兩種給水管網(wǎng)定線方案，見圖水初-08（管網(wǎng)定線圖一）和水初-09（管網(wǎng)定線圖二）。由于管網(wǎng)定線圖二有部分管線長度遠低于給水管網(wǎng)定線要求，故給水管網(wǎng)定線選擇水初-08（管網(wǎng)定線圖一）的定線方案。1.4管網(wǎng)水力計算1.4.1節(jié)點流量計算本設(shè)計為方便計算比流量qs（1）比流量qq式中qs——比流量，L/（s·m）Q——管網(wǎng)最高時用水量，L/s；∑q——大用戶集中用水量總和，L/s；∑l——管線計算總長度，m。（2）沿線流量qq式中ql——沿線流量，L/sl——該管段沿線長度，m。（3）節(jié)點流量qq式中qi——節(jié)點流量，L/s即任一節(jié)點i的節(jié)點流量qi等于與該節(jié)點相連各管段的沿線流量q1.4.2事故時節(jié)點流量為保證管網(wǎng)供水安全，應(yīng)斷開流量最大的管段進行事故管網(wǎng)計算，事故時節(jié)點流量均以最高時節(jié)點流量的70%計算，即q1.4.3消防時節(jié)點流量為保證消防時各點水量和水壓滿足要求，最不利的和次不利點節(jié)點流量為q1.4.4管網(wǎng)水力要求（1）管段界限流量本設(shè)計LB市HX區(qū)經(jīng)濟因素取f=0.8，為減小管網(wǎng)的年費用，該管網(wǎng)界限流量表如下。界限流量表表4-1管徑（mm）界限流量（L/s）當?shù)亟?jīng)濟因素為f=0.8時的管段流量（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）流速要求為了防止管網(wǎng)因為水錘作用發(fā)生事故，所以管段的最大流速不應(yīng)超過2.5m/s；同時為了避免水中懸浮物在管網(wǎng)中沉降，故管段的最低流速一般不得小于0.6m/s。（3）阻力系數(shù)為防止管網(wǎng)水頭損失過大，增大水泵揚程，使管網(wǎng)運行費用增加，故一般規(guī)定管徑大于等于400mm的管段1000i宜小于3，管徑小于400mm的管段1000i宜小于5。1.4.5管網(wǎng)水力計算結(jié)果（1）各工況下的節(jié)點壓力與自由水頭各工況下的節(jié)點壓力與自由水頭表4-2節(jié)點編號地面標高

（m）最高時事故時消防時節(jié)點流量

（L/s）總水頭

（m）自由水頭

（m）節(jié)點流量

（L/s）總水頭

（m）自由水頭

（m）節(jié)點流量

（L/s）總水頭

（m）自由水頭

（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合計648.15453.69798.17（2）各工況下水泵參數(shù)各工況下水泵參數(shù)表4-3工況凈水廠總水頭需要流量（L/s）需要流量（m3/h）最高時126.99648.152333.33事故時132.10453.701633.33消防時118.72798.152873.33注：凈水廠總水頭是以凈水廠地面高程87.00m計。（3）最高時管段水力最高時管段水力表表4-4管段編號管長

（m）管徑

（mm）Ch流量

（L/s）流速

（m/s）1000i水頭損失

（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）事故時管段平差結(jié)果事故時管段平差結(jié)果表4-5管段編號管長

（m）管徑

（mm）Ch流量

（L/s）流速

（m/s）1000i水頭損失

（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）消防時管段平差結(jié)果消防時管段平差結(jié)果表4-6管段編號管長

（m）管徑

（mm）Ch流量

（L/s）流速

（m/s）1000i水頭損失

（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