城市给水工程给水管网设计二方案.docx

城市给水工程给水管网设计二方案1.1管网定线12居民区给水管网系统设计计算1 .3工业区给水管网系统设计计算1.1 管网定线B市分为三个区，其中，I区的房屋层数平均为6层，11区的房屋层数平均为7层，III区的房屋层数平均为8层。并且口、IU区地区的地势较高，所以“、UI区对水压的要求较高，属于高压区；其它地区属于低压区。所以本方案的居民区供水采用并联分区给水系统。各区由同一泵站供给，高压泵将水输送给高压区，低压泵将水输送给低压区，共设置四条输水管，高压泵连两条，低压泵连两条，这样供水比较可靠，而且管理方便。工业区依然另设水源取水，采用树状管网集中供应（同方案一）。1.2 居民区给水管网系统设计计算图LI居民区给水管网示意水厂1的设计规模、居民区用水规律、是否设置水塔的讨论和清水池有效容积的计算这四个步骤同方案一。(1)管网的设计流量管网分为高压区和低压区两个区域，总的设计流量仍以最高日最高时的流量作为设计流量，Qh=2981.3LSo高压区为II、IlI区供水，低压区为I区供水，n、III区共有人口55万人，I区有人口10万人，则高压区供水量约是低压区的1.5倍，所以：高压区供水量：=2522.64L/s低压区供水量：=458.66L/s（2）沿线流量和节点流量的确定表1.1高压区管段长度表管段编号图上距离cm实际长度m配水长度m17.878039029.898049037.979079048.3830415518.41840184069.999099079.494047086.464032097.5750750107.1710710119.99904951211.911901190139.9990990144.7470470156.5650650167.8780390177.2720720186.56506501914.6146014602011.71570785219.4940940227.97907902310.510505252411.511501150252.7270270266.6660660279.29209202810.7107053520755表1.2低压区管段长度表管段编号图上距离cm实际长度m配水长度m2910.11010505309.19104553110.91090545续表1.2管段编号图上距离cm实际长度m配水长度m329.2920920338.28204103412.3123012303513.213201320361.1510255377.2720720384.2420210398.78704354011.611605807585引入长度比流量q,则高压区：q=Ql÷>2522.64÷20755=0.121541.(s.m)(5-1)低压区：q=Q2÷L=458.66÷7585=0.0605L(s.m)(5-2)由此可以算出各个管段的沿线流量:表1.3高压区管段沿线流量管段编号实际长度m配水长度m管段沿线流量1./s178039047.40298049059.56379079096.02483041550.44518401840223.646990990120.33794047057.13864032038.89975075091.161071071086.301199049560.161211901190144.6413990990120.331447047057.131565065079.001678039047.401772072087.511865065079.001914601460177.45续表1.3管段编号实际长度m配水长度m管段沿线流量1./s20157078591.4121940940114.252279079096.0223105052563.812411501150139.782527027032.822666066080.2227920920111.8228107053561.03207552522.64表14低压区管段沿线流量表管段编号实际长度m配水长度m管段沿线流量1./s29101050530.543091045527.5131109054532.963292092051.633382041024.79341230123074.38351320132079.823651025511.423772072043.543842021012.703987043526.3040116058031.077585458.66由于流量变化的管段难以确定管径和水头损失，所以将管段的沿线流量转化为节点流量（以流出节点为正，流入节点为负），则:表1.5高压区节点流节点编号节点设计流量L/s123.702101.49351.004131.275261.57量表节点编 号节点设计流量L/s12117.2913112.7314148.8915127.6216101.79节点编 号节点设计流量L/s6157.10758.648111.479221.82续表1.5节点编 号节点设计流量L/s1786.3018112.4319177.152080.2210171.3811156.79累计2522.64节点编 号节点设计流量L/s2131.752256.842326.152461.3825126.68节点编号节点设计流量L/s2658.662720.862852.462923.89累计458.66表1.6 低压区节点流量表(3)管段水力计算首先，进行管网初分配,即利用最大时用水量对管网进行流量分配，初步确定管段的计算流量，确定管段的管径。将初步确定好的管径、节点流量输入平差软件进行平差，这时管段的流量将会按照管网的水力特性进行分配，其数值并不等于初分配时的流量。具体数据如下表：表1.7高压区管段水力计算结果编号长度直径流量流速单位水总损失头损失mmmLPSm/sm/kmm178030023.700.340.610.48298035069.330.722.102.06379030051.860.792.982.354830450124.330.781.821.515184035049.050.511.102.02699040073.650.591.221.2179403009.950.140.120.118640500180.320.922.171.399750500198.731.012.591.9410710700341.140.901.400.991199060068.590.240.150.15121190600211.340.761.241.481399040032.090.260.260.26续表1.7编号长度直径流量流速单位水头损失总损失mmmLPSm/sm/kmm14470700207.130.540.540.2515650600162.250.570.730.4716780900511.130.800.850.6617720500173.10.882.011.451186501000751.740.961.050.68191460500111.910.570.901.3120157030023.630.330.610.9621940900472.270.740.740.7022790600150.270.530.640.5123105013001096.140.830.580.6124115013001324.721.000.830.952527013001238.420.930.730.20266601000733.090.930.990.65279201000392.910.500.310.29281070500103.850.530.780.8343240013001261.320.950.761.8244240013001261.320.950.761.82表1.8低压区管段水力计算结果长度直径流量流速单位水头损失总损失编号mmmLPSm/sm/kmm29101030044.360.631.941.96309101002.990.382.782.5331109035076.110.792.492.713292020011.480.491.991.833382025023.160.471.421.1634123035073.120.762.312.8435132020017.200.552.423.1936510600210.600.741.190.613772035086.250.903.142.263842030064.610.913.901.6439870600227.210.801.371.1940116035088.500.923.303.8341500600229.30.811.390.70442500600229.340.811.390.70(4)高压区选泵高压泵最大扬程的确定首先，要假设一个控制点。高压区中节点【6】所处的位置是B市最高的，并且【6】所在的区域平均楼层为8层,对水压要求较高。所以选择【6】为高压区的控制点。并以61作为高压管网的定压节点进行平差。节点【6】的总水头为317.50+36=353.50m。以此平差，结果如下表：表1.9平差结果编号标高需水量总水头自由水头mLPSmm1300.0023.70349.4649.462301.00101.49349.9344.933308.0051.00351.9943.994300.00131.27354.3254.325306.50261.57352.2941.796317.50157.10353.5036.007301.0058.64353.6148.618300.50111.47351.7151.219301.30221.82354.2348.9310311.00171.38354.4939.4911314.70156.79354.2439.5412307.80117.29353.7641.9613300.00112.73356.3756.3714304.00148.89351.6851.6815308.00127.62351.1847.1816300.00101.79356.9856.9817303.6086.30356.0352.4318301.00112.43351.8350.8319306.80177.15351.5448.7420302.5080.22354.7152.21分析上表，发现所有的水压都满足要求，所以当初假设的控制点是正确的，【6】为高压管网中的控制点。水泵最大扬程Hp：Hp=(H2-H1)+10.67q18521Cw1852D487+hpm(5-3)=356.98-295+1.82+8.0x2.02/2/9.81=61.43m高压泵选型参考给水排水设计手册第H册常用设备，则选则5台600S75A型水泵(南京古尔兹制泵有限公司)作为高压泵，四用一备，并联使用。水泵参数如下：表LlO600S75A型水泵主要参数型号流量扬程转速轴功率电动机功率效气蚀余量r3hmr/minkWkW%m600S7528862970608710808.1A0以上是泵在最高效运行条件下的参数，而实际运行中，在用水高峰期4台泵均开启，每台泵的流量为63066Ls,扬程为69.82mo在用水低峰期可以通过调节开启泵的台数来进行调节。高压泵选型后平差结果表1.11管段水力计算结果编号长度直径流速单位水头损失总损失mmmLPSm/sm/kmm178030023.700.340.610.48298035069.330.722.102.06379030051.860.792.982.354830450124.330.781.821.515184035049.050.511.102.02699040073.650.591.221.2179403009.950.140.120.118640500180.320.922.171.399750500198.731.012.591.9410710700341.140.901.400.991199060068.590.240.150.15121190600211.340.761.241.481399040032.090.260.260.2614470700207.130.540.540.2515650600162.250.570.730.4716780900511.130.800.850.6617720500173.110.882.011.45186501000751.740.961.050.68191460500111.910.570.901.3120157030023.630.330.610.9621940900472.270.740.740.7022790600150.270.530.640.5123105013001096.140.830.580.6124115013001324.721.000.830.952527013001238.420.930.730.20266601000733.090.930.990.65279201000392.910.500.310.29续表1.11编号氏度直径流速单位水头损失总损失mmmLPSm/sm/kmm281070500103.850.530.780.8343240013001261.320.950.761.8244240013001261.320.950.761.82表1.12节点计算结果编号标高需水量总水头自由水头mLPSmm1300.0023.70351.4851.482301.00101.49351.9650.963308.0051.00358.0150.014300.00131.27360.3460.345306.50261.57358.3151.816317.50157.10359.5242.027301.0058.64359.6454.648300.50111.47361.7361.239301.30221.82360.2654.9610311.00171.38360.5241.5211314.70156.79360.2641.5612307.80117.29359.7851.9813300.00112.73362.3962.3914304.00148.89361.7057.7015308.00127.62361.2053.2016300.00101.79363.0163.0117303.6086.30362.0558.4518301.00112.43361.8656.8619306.80177.15361.5754.7720302.5080.22360.7358.23从节点平差结果可以看出控制点【6】的自由水压为42.02m,满足要求，其它点也满足要求。(5)低压区选泵低压泵最大扬程的确定首先，要假设一个控制点。选低压区中距离二级泵站最远的节点23为低压区的控制点。并以23作为低压管网的定压节点进行平差。节点【23】的总水头为303.60+28=331.60mo以此平差，结果如下表：表1.13平差结编号标IwJ需水量总水头自由水头mLPSmm21300.0031.75336.0936.0922300.8056.84334.1333.3323303.6026.15331.6028.0024300.0061.38338.8138.8125300.00126.68331.9631.9626300.5058.66332.7632.2627300.0020.86339.4139.4128300.0052.46338.2238.2229300.0023.89334.4034.40分析上表，发现所有的水压都满足要求，所以当初假设的控制点是正确的，【23】为低压管网中的控制点。水泵最大扬程Hp：HP=(H2-Hi)+10.67q,8521Cwk852D487+hpm(5-4)=339.41-295+0.7+8.0×2.0229.81=46.74m低压泵的选择参考给水排水设计手册第11册常用设备，则选则3台12SA10型水泵作为低压泵，二用一备，并联使用。水泵参数如下：表1.1412SA10型水泵主要参数型号流量扬程转速轴功率电动机功率效率气蚀余量L/smr/minkWkW%m12SA10220541450139160841.8以上是泵在最高效运行条件下的参数，而实际运行中，在用水高峰期2台泵均开启，每台泵的流量为229.34Ls,扬程为52.44mo低压泵选择后的平差结果表1.15管段水力计算结果编j=j长度直径流量流速单位水头损失总损失mmmLPSm/sm/kmm29101030044.360.631.941.96309101002.990.382.782.5331109035076.110.792.492.713292020011.480.491.991.83续表L15编长度直径流量流速单位水头总损失号损失mmmLPSm/sm/kmm3382025023.160.471.421.1634123035073.120.762.312.8435132020017.200.552.423.1936510600210.600.741.190.613772035086.250.903.142.263842030064.610.913.901.6439870600227.210.801.371.1940116035088.500.923.303.8341500600229.340.811.390.7042500600229.340.811.390.70表1.16节点计算结果编节标高需水量总水头自由水头mLPSmm21300.0031.75343.4243.4222300.8056.84341.4640.6623303.6026.15338.9331.3324300.0061.38346.1446.1425300.00126.68343.2943.2926300.5058.66340.0939.5927300.0020.86346.7446.7428300.0052.46341.5541.5529300.0023.89341.7341.73从节点平差结果可以看出控制点【23】的自由水压为31.33m,满足要求，其它各点也满足要求。(6)管网设计校核分两种情况校核：消防工况和事故工况。由于没有设置水塔，无需进行水塔转输工况校核。消防工况校核低压区负责一区的供水，一区共10万人，按照同一时间内2次火灾计算，一次灭火用水量为35Ls,加在22和控制点【23】两点上。高压区负责二、三区的供水，这两区共55万人，按照同一时间内3次火灾计算，一次灭火用水量为85Ls,分别加在控制点【6】、距离二级泵站较远的【1】和地势较高的11这三点上。表1.17高压区节点计算结果编节标高需水量总水头自由水头mLPSmm1300.00108.70339.3439.342301.00101.49347.3142.313308.0051.00352.3644.364300.00131.27356.8956.895306.50261.57353.9247.426317.50242.10354.9837.487301.0058.64351.5150.518300.50111.47358.4457.949301.30221.82356.5751.2710311.00171.38356.6541.6511314.70241.79356.2241.5212307.80117.29351.7247.9213300.00112.73359.2159.2114304.00148.89358.3654.3615308.00127.62357.6249.6216300.00101.79359.9259.9217303.6086.30358.7551.1518301.00112.43358.5053.5019306.80177.15358.1751.3720302.5080.22357.2354.73表1.18高压区管段水力计算结果编.长度直径流量流速单位水头损失总损失mmmLPSm/sm/kmm1780300108.701.5410.227.972980350112.611.171.151.05379030097.581.388.376.614830450167.611.053.162.625184035060.160.631.612.96699040068.530.551.071.06794030022.710.320.560.538640500191.430.972.421.559750500234.461.193.522.6410710700451.531.182.341.661199060081.350.290.200.20121190600241.130.871.571.871399040016.920.130.080.08续表1.18编号长度直径流量流速单位水头损失总损失mmmLPSm/sm/kmm14470700271.530.710.900.4215650600168.260.600.780.5116780900552.040.870.980.7617720500194.230.992.491.79186501000911.361.171.500.98191460500138.520.711.331.9420157030030.380.430.961.5121940900527.710.830.900.8522790600184.590.650.930.7323105013001192.480.900.680.7124115013001483.381.121.021.172527013001397.081.050.910.25266601000858.391.091.330.88279201000426.270.540.360.33281070500110.600.560.880.9443240013001388.831.050.902.1644240013001388.831.050.902.16表1.19低压区节点计算结果编号标高需水量总水头自由水头mLPSmm21300.0031.75334.7434.7422300.8091.84330.2829.4823303.6061.15323.4719.8724300.0061.38339.3139.3125300.00126.68331.7431.7426300.5058.66329.4428.9427300.0020.86340.1140.1128300.0052.46338.5538.5529300.0023.89332.4632.46表1.20低压区管段水力计算结果编节长度直径流量流速单位水头损失总损失mmmLPSm/sm/kmm29101030069.050.984.414.45309101001.110.657.496.82续表1.20编号长度直径流量流速单位水头损失总损失mmmLPSm/sm/kmm311090350100.801.054.194.573292020027.900.891.941.463382025056.041.147.281.9734123035082.560.862.903.5735132020024.810.794.786.3136510600244.730.871.570.803772035096.841.013.892.803842030089.891.277.193.0239870600263.080.931.791.56401160350113.781.181.256.0941500600264.340.931.810.9142500600264.340.931.810.91从上述结果可以看出，高压区、低压区各节点自由水头均大于IOm,满足消防服务水头。并且个别管段放大后的整体流速没有过大，所以管径也能通过消防校核。事故工况校核国家有关规范规定，城市给水管网在事故工况下，必须保证70%以上的供水量。按照最不利工况进行校核。高压区靠近二级泵站的管段【24】以及低压区靠近二级泵站的管段39在最高时损坏的情况。各节点流量变为原来最高时流量的70%,将各个节点的流量变为原来的70%,除去管段【24】和【39，进行平差，发现【22】的流速偏大,所以放大其管径，由原来的DN600变为DN700。再次平差，最终结果如下：表1.21高压区管段水力计算结果编节长度直径i流速G位水头损失总损失mmmLP