某污水處理廠的污水管渠系統(tǒng)設計計算案例目錄TOC\o"1-3"\h\u31871某污水處理廠的污水管渠系統(tǒng)設計計算案例 1167021污水管道的布置 1232612服務面積法計算管段設計流量 1126973設計管段設計流量的計算 2289394設計管段的水力計算 71污水管道的布置布置污水管道需要考慮地形、所處地點以及地下的土壤的因素等。本設計干管的布置使用的方式是截流式，就是沿坡度方向布置干管，然后在位置低的地方沿污水廠方向布置主干管，支管主要采用穿坊式布置。2服務面積法計算管段設計流量依據(jù)設計管段的分類以及概念，把每根干管里有本段流量流入的位置作為街坊的兩端，旁側有支管接入或者有集中流量流入的井作為設計管段的起始位置，并且給該井一個序號。匯水面積的劃分一般依據(jù)就近原則，讓污水在重力的作用下以流入最近的污水管。各街坊匯水面積詳見表4-1。表4-1街坊匯水面積表編號面積/ha編號面積/ha編號面積/ha16.9225.9435.928.3236.1449.436.6245.7457.845.8255.8464.255.4263.5479.665.8277.6489.875.6288.4499.485.3296.7506.095.1306.5515.9106.8315.5526.8116.4324.9536.4124.8333.9546.8136.6345.9557.0147.6354.8567.6155.1367.0573.0165.2377.2589.6174.6386.8598.3184.9397.0606.8196.7409.3616.0206.3416.9629.2215.0425.9街坊的總面積為401.6公頃。3設計管段設計流量的計算居民區(qū)的人口密度P為P=式中：N——遠期規(guī)劃設計人口； F——街坊的總面積。由前文可知本設計平均日用水定額q=120L/（人·d）。所以污水比流量為q污水管道的總設計流量確定：本段平均流量=街坊面積F×污水比流量q轉輸平均流量是指連接該段的上游污水管道的平均生活污水流量；合計平均流量Q總變化系數(shù)KzK居民生活污水設計流量Q本段集中流量Q2為管段上游的井進入污水管道的集中流量；總設計流量=居民生活污水設計流量+集中流量所以污水管道設計流量見表4-2表4表4-2污水管道設計流量計算表管段編號管道長度L(m)設計流量Q(L/s)管徑D(mm)坡度I流速v(m/s)充滿度降落量I*L(m)標高(m)埋深(m)h/Dh(m)地面水面管內底上端下端上端下端上端下端上端下端1-2263.599.813000.00160.600.280.080.444.474.342.572.142.492.051.982.292-3263.7911.893000.00140.600.320.100.384.344.172.141.762.041.662.302.5112-3355.488.593000.00180.600.260.080.664.434.172.531.872.451.791.982.383-4345.9023.143000.00090.600.540.160.314.173.931.761.451.601.292.572.6413-14262.098.303000.00190.600.250.080.504.224.072.321.822.241.741.982.3314-4262.098.303000.00190.600.250.080.504.073.931.821.321.741.242.332.694-5443.7532.883500.00070.600.550.190.313.933.511.321.011.120.812.812.7015-16247.108.663000.00180.600.260.080.463.823.571.921.461.841.381.982.1916-5247.1012.833000.00130.600.340.100.333.573.511.461.131.361.032.212.485-6393.2746.404000.00060.600.590.240.223.513.331.010.790.770.552.742.7817-6444.899.323000.00170.600.270.080.773.463.331.560.791.480.711.982.6218-6341.6510.093000.00160.600.290.090.553.153.331.260.701.170.621.982.716-7228.0276.345000.00040.600.620.310.093.333.250.700.610.390.302.942.957-8312.3191.385000.00040.600.610.310.113.253.080.610.500.300.192.952.8919-20271.866.803000.00220.600.220.070.614.174.132.261.652.191.581.982.5520-21271.869.123000.00170.600.270.080.484.134.121.651.171.571.082.563.0425-21380.563.723000.00300.560.150.051.154.414.122.481.322.431.281.982.8421-22344.7316.913000.00110.600.420.130.384.123.741.170.791.040.663.083.0826-27270.2512.663000.00130.600.340.100.373.913.832.031.661.931.561.982.2727-22270.2523.313000.00090.600.540.160.243.833.741.661.431.501.262.332.4822-23147.3245.944000.00060.600.590.230.083.743.550.790.700.550.473.193.0830-23239.7616.983000.00110.600.420.130.263.523.551.671.401.541.281.982.2723-24305.9239.673500.00060.600.650.230.193.553.360.700.510.480.283.073.08管段編號管段編號管道長度L(m)設計流量Q(L/s)管徑D(mm)坡度I流速v(m/s)充滿度降落量I*L(m)標高(m)埋深(m)h/Dh(m)地面水面管內底上端下端上端下端上端下端上端下端28-29222.0210.443000.00160.600.290.090.353.503.471.611.261.521.171.982.3029-24312.1414.843000.00120.600.380.110.383.473.361.260.881.140.762.332.6031-24260.3023.513000.00090.600.540.160.233.313.361.491.261.331.101.982.2624-8393.0680.515000.00040.600.650.320.153.363.080.510.360.190.033.173.0532-8354.873.013000.00300.530.140.041.082.843.080.90-0.180.86-0.221.983.308-9347.30177.397500.00020.600.630.480.083.083.03-0.18-0.26-0.65-0.733.733.7642-9385.465.013000.00280.600.180.051.112.703.030.77-0.340.72-0.391.983.429-10235.75206.438000.00020.600.650.520.053.033.01-0.34-0.39-0.86-0.903.893.9133-34287.4810.283000.00160.600.290.090.464.124.102.231.772.141.681.982.4234-35287.4813.753000.00130.600.360.110.374.104.051.771.401.661.292.442.7639-35310.616.303000.00240.600.210.060.744.234.052.311.572.251.511.982.5435-36252.0426.383500.00080.600.470.160.204.053.771.401.191.241.032.812.7436-37252.0426.383500.00080.600.470.160.203.773.471.190.991.030.832.742.6440-37330.8222.173000.00090.600.520.160.303.523.471.701.401.541.241.982.2337-38306.1351.094000.00050.600.640.260.163.473.280.990.830.730.572.742.7141-38311.5210.473000.00160.600.300.090.493.313.281.420.931.330.841.982.4438-10392.1360.584500.00050.600.610.270.183.283.010.830.640.550.372.732.6410-11348.21263.179000.00020.600.650.590.063.012.95-0.39-0.45-0.97-1.043.983.9943-44426.4015.923000.00110.600.400.120.494.053.872.191.702.071.581.982.2944-45468.2323.433000.00090.600.540.160.413.873.441.701.301.541.132.332.3148-45398.1212.183000.00140.600.330.100.563.473.441.591.031.490.931.982.5145-46357.6452.824500.00050.600.540.240.183.443.241.030.850.790.612.652.6349-46368.2837.913500.00060.600.620.220.243.283.241.521.281.301.061.982.18管段編號管段編號管道長度L(m)設計流量Q(L/s)管徑D(mm)坡度I流速v(m/s)充滿度降落量I*L(m)標高(m)埋深(m)h/Dh(m)地面水面管內底上端下端上端下端上端下端上端下端46-47283.0885.685000.00040.600.680.340.113.243.040.850.740.510.402.732.6447-11107.2193.025500.00030.600.620.340.043.042.950.740.700.400.362.642.5911-污水廠32.78348.1110000.00010.600.690.690.012.952.93-0.45-0.45-1.14-1.154.094.084設計管段的水力計算在設計管道中的流量的數(shù)值明確之后，就可以自上游往下游依次進行水力計算。水力計算的詳細步驟如下：測量所繪制的污水管道平面布置圖上各個設計管段長度；計算每個管段的設計流量和設計管段起點和終點處檢查井的地面；通過查《給排水設計手冊》中的水力計算表，從而以確定各個管段的坡度、管徑、流速以及充滿度?？梢砸罁?jù)管道的流量來確定管徑，然后憑借所知的流量以及流速在相應的表中尋到相對應的充滿度和坡度值。如果兩個值都符合設計規(guī)范的要求，則表明這段管道的水力計算沒有產(chǎn)生誤差。算出各個管段的上、下端的管內底、水面標高及其埋深。各個管段上、下端的管內底、水面標高及其埋深的計算方法見下文。剛開始先確定管道各個起始點的埋沒深度：1點是主干管的起點，假設它所在點埋深為1.98m，則其他干管的起點埋深也為1.98m。通過管內底的標高來算出埋深和水面標高，計算方法為埋設深度=地面標高?管內底標高水面標高=管內底標高+水深降落量和下端管內底標高的計算方法為降落量=管段長度×坡度下端管內底標高=上端管內底標高?降落量依據(jù)相鄰管段直接的連接方式，可以利用上游的水面標高計算出下游的水面標高，管內底的標高也是一樣。相鄰的管段的管徑不同的話，可以使用管頂平接的方式，管徑相同的話，可以使用水面平接的方式。在水力計算的時候，需要留意幾個小地方：在選擇控制點時需要細心。在計算設計管段的坡度時需要細心。污水從上游往下游流去時，設計流量一般會慢慢變大，設計流速也會對應的變大。但假若設計流量保持不變的話，管段內的設計流速也不能變小。設計流量慢慢變大的話，設計管徑也應該相對應的慢慢增加。假若設計流量保持不變的話，管段的管徑也不能減小，當坡度小的管道與坡度大的在上下游相連時，管徑也可以稍稍減少，減少的范圍應在50~100mm之間。為能夠減少當水流通過檢查井時的局部水損，井底在呈直線的管線上需要嚴格的設置成直線，轉彎的位置則需要設置成均勻的曲線。污水干管水力計算如表4-3表4表4-3污水干管水力計算表管段編號管道長度L(m)設計流量Q(L/s)管徑D(mm)坡度I流速v(m/s)充滿度降落量I*L(m)標高(m)埋深(m)h/Dh(m)地面水面管內底上端下端上端下端上端下端上端下端1-2263.599.813000.00160.600.280.080.444.474.342.572.142.492.051.982.292-3263.7911.893000.00140.600.320.100.384.344.172.141.762.041.662.302.5112-3355.488.593000.00180.600.260.080.664.434.172.531.872.451.791.982.383-4345.9023.143000.00090.600.540.160.314.173.931.761.451.601.292.572.6413-14262.098.303000.00190.600.250.080.504.224.072.321.822.241.741.982.3314-4262.098.303000.00190.600.250.080.504.073.931.821.321.741.242.332.694-5443.7532.883500.00070.600.550.190.313.933.511.321.011.120.812.812.7015-16247.108.663000.00180.600.260.080.463.823.571.921.461.841.381.982.1916-5247.1012.833000.00130.600.340.100.333.573.511.461.131.361.032.212.485-6393.2746.404000.00060.600.590.240.223.513.331.010.790.770.552.742.7817-6444.899.323000.00170.600.270.080.773.463.331.560.791.480.711.982.6218-6341.6510.093000.00160.600.290.090.553.153.331.260.701.170.621.982.716-7228.0276.345000.00040.600.620.310.093.333.250.700.610.390.302.942.957-8312.3191.385000.00040.600.610.310.113.253.080.610.500.300.192.952.8919-20271.866.803000.00220.600.220.070.614.174.132.261.652.191.581.982.5520-21271.869.123000.00170.600.270.080.484.134.121.651.171.571.082.563.0425-21380.563.723000.00300.560.150.051.154.414.122.481.322.431.281.982.8421-22344.7316.913000.00110.600.420.130.384.123.741.170.791.040.663.083.0826-27270.2512.663000.00130.600.340.100.373.913.832.031.661.931.561.982.2727-22270.2523.313000.00090.600.540.160.243.833.741.661.431.501.262.332.4822-23147.3245.944000.00060.600.590.230.083.743.550.790.700.550.473.193.08管段編號管段編號管道長度L(m)設計流量Q(L/s)管徑D(mm)坡度I流速v(m/s)充滿度降落量I*L(m)標高(m)埋深(m)h/Dh(m)地面水面管內底上端下端上端下端上端下端上端下端30-23239.7616.983000.00110.600.420.130.263.523.551.671.401.541.281.982.2723-24305.9239.673500.00060.600.650.230.193.553.360.700.510.480.283.073.0828-29222.0210.443000.00160.600.290.090.353.503.471.611.261.521.171.982.3029-24312.1414.843000.00120.600.380.110.383.473.361.260.881.140.762.332.6031-24260.3023.513000.00090.600.540.160.233.313.361.491.261.331.101.982.2624-8393.0680.515000.00040.600.650.320.153.363.080.510.360.190.033.173.0532-8354.873.013000.00300.530.140.041.082.843.080.90-0.180.86-0.221.983.308-9347.30177.397500.00020.600.630.480.083.083.03-0.18-0.26-0.65-0.733.733.7642-9385.465.013000.00280.600.180.051.112.703.030.77-0.340.72-0.391.983.429-10235.75206.438000.00020.600.650.520.053.033.01-0.34-0.39-0.86-0.903.893.9133-34287.4810.283000.00160.600.290.090.464.124.102.231.772.141.681.982.4234-35287.4813.753000.00130.600.360.110.374.104.051.771.401.661.292.442.7639-35310.616.303000.00240.600.210.060.744.234.052.311.572.251.511.982.5435-36252.0426.383500.00080.600.470.160.204.053.771.401.191.241.032.812.7436-37252.0426.383500.00080.600.470.160.203.773.471.190.991.030.832.742.6440-37330.8222.173000.00090.600.520.160.303.523.471.701.401.541.241.982.2337-38306.1351.094000.00050.600.640.260.163.473.280.990.830.730.572.742.7141-383