输配水管网-管网水力计算

管网水力计算目录1

管径确定2

水力计算案例管径确定01一、管径确定计算公式：

D－管段直径，m；q－管段流量，m3/s；υ—管中流速，m/s。

vmax<2.5~3m/s；vmin>0.6m/s（1）设计流速小，管径大，管网造价增加；水头损失减小，水泵扬程降低，电费降低。（2）设计流速大，管径就小，管网的造价就会降低，但管段水头损失增大，所需的水泵扬程将提高。管网费用与流速的关系经济流速：一定年限T年内管网造价和管理费用（主要是电费）之和最小的流速。一、管径确定管

径（mm）平均经济流速（m/s）管径(mm)平均经济流速（m/s）100～3500.6～0.9≥4000.9～1.4经济流速法经济流速法管径(mm)界限流量（L/s）管径(mm)界限流量（L/s）管径(mm)界限流量（L/s）100＜935068～96700355～4901509～1540096～130800490～68520015～28.5450130～168900685～82225028.5～45500168～2371000822～112030045～68600237～355水力计算案例02某镇给水管网布置及管段长度如图所示。管网最高用水时用水量Qh=97.15L/s，各节点流量标注于图上。各点最小服务水头相同Hc=20m。各点地面高程及吸水井最低水位列于表1。试进行树状网水力计算。树状网水力计算节点01234567地面高程（m）32.032.532.131.432.734.233．1531．8节点89101112吸水井水塔地面高程（m）32.132.032.332.032.329．032．0表1节点地面高程二、水力计算案例树状网水力计算节点01234567地面高程（m）32.032.532.131.432.734.233．1531．8节点89101112吸水井水塔地面高程（m）32.132.032.332.032.329．032．0表1节点地面高程二、水力计算案例

首先选择控制点，确定干管管线。二、水力计算案例根据控制点，编写干管管段编号。表2干线水力计算管段管长L(m)流量q(L/s)管径D（m）流速υ(m/s)水力坡度1000i水头损失(m)节点水压高程（m）地面高程（m）自由水压（m）①②③④⑤⑥⑦⑧⑨⑩⑪

5~43006.951000.918.15.43554.234.220.0459.6332.726.934~320034.152500.73.450.69360.3231.428.923~236058.853000.833.71.33261.6532.129.552~145088.653500.923.711.67163.3232.530.821~041097.153501.014.371.79065.1132.033.11实际长度。表2干线水力计算管段管长L(m)流量q(L/s)管径D（m）流速υ(m/s)水力坡度1000i水头损失(m)节点水压高程（m）地面高程（m）自由水压（m）①②③④⑤⑥⑦⑧⑨⑩

⑪

5~43006.951000.918.15.43554.234.220.0459.6332.726.934~320034.152500.73.450.69360.3231.428.923~236058.853000.833.71.33261.6532.129.552~145088.653500.923.711.67163.3232.530.821~041097.153501.014.371.79065.1132.033.11二、水力计算案例管段流量指本管段后所有节点流量之和。表2干线水力计算管段管长L(m)流量q(L/s)管径D（m）流速υ(m/s)水力坡度1000i水头损失(m)节点水压高程（m）地面高程（m）自由水压（m）①②③④⑤⑥⑦⑧⑨⑩

⑪

5~43006.951000.918.15.43554.234.220.0459.6332.726.934~320034.152500.73.450.69360.3231.428.923~236058.853000.833.71.33261.6532.129.552~145088.653500.923.711.67163.3232.530.821~041097.153501.014.371.79065.1132.033.11二、水力计算案例干管：对起点水压未知的管网计算，参考经济流速确定D、流速和水力坡度Dmin=100mm表2干线水力计算管段管长L(m)流量q(L/s)管径D（m）流速υ(m/s)水力坡度1000i水头损失(m)节点水压高程（m）地面高程（m）自由水压（m）①②③④⑤⑥⑦⑧⑨⑩

⑪

5~43006.951000.918.15.43554.234.220.0459.6332.726.934~320034.152500.73.450.69360.3231.428.923~236058.853000.833.71.33261.6532.129.552~145088.653500.923.711.67163.3232.530.821~041097.153501.014.371.79065.1132.033.11水头损失一般100m不超过1m二、水力计算案例干管：对起点水压未知的管网计算，参考经济流速确定D、流速和水力坡度Dmin=100mm表2干线水力计算管段管长L(m)流量q(L/s)管径D（m）流速υ(m/s)水力坡度1000i水头损失(m)节点水压高程（m）地面高程（m）自由水压（m）①②③④⑤⑥⑦⑧⑨⑩

⑪

5~43006.951000.918.15.43554.234.220.0459.6332.726.934~320034.152500.73.450.69360.3231.428.923~236058.853000.833.71.33261.6532.129.552~145088.653500.923.711.67163.3232.530.821~041097.153501.014.371.79065.1132.033.11二、水力计算案例干管：对起点水压未知的管网计算，参考经济流速确定D、流速和水力坡度Dmin=100mm表2干线水力计算管段管长L(m)流量q(L/s)管径D（m）流速υ(m/s)水力坡度1000i水头损失(m)节点水压高程（m）地面高程（m）自由水压（m）①②③④⑤⑥⑦⑧⑨⑩

⑪

5~43006.951000.918.15.43554.234.220.0459.6332.726.934~320034.152500.73.450.69360.3231.428.923~236058.853000.833.71.33261.6532.129.552~145088.653500.923.711.67163.3232.530.821~041097.153501.014.371.79065.1132.033.11水头损失一般100m不超过1m二、水力计算案例干管：对起点水压未知的管网计算，参考经济流速确定D、流速和水力坡度Dmin=100mm管段管长L(m)流量q(L/s)管径D（m）流速υ(m/s)水力坡度1000i水头损失(m)节点水压高程（m）地面高程（m）自由水压（m）①②③④⑤⑥⑦⑧⑨⑩

⑪

5~43006.951000.918.15.43554.234.220.0459.6332.726.934~320034.152500.73.450.69360.3231.428.923~236058.853000.833.71.33261.6532.129.552~145088.653500.923.711.67163.3232.530.821~041097.153501.014.371.79065.1132.033.11二、水力计算案例水头损失(7)=

1000i(6)/1000×管长L(2)=表2干线水力计算管段管长L(m)流量q(L/s)管径D（m）流速υ(m/s)水力坡度1000i水头损失(m)节点水压高程（m）地面高程（m）自由水压（m）①②③④⑤⑥⑦⑧⑨⑩

⑪

5~43006.951000.918.15.43554.234.220.0459.6332.726.934~320034.152500.73.450.69360.3231.428.923~236058.853000.833.71.33261.6532.129.552~145088.653500.923.711.67163.3232.530.821~041097.153501.014.371.79065.1132.033.11二、水力计算案例节点表2干线水力计算管段管长L(m)流量q(L/s)管径D（m）流速υ(m/s)水力坡度1000i水头损失(m)节点水压高程（m）地面高程（m）自由水压（m）①②③④⑤⑥⑦⑧⑨⑩

⑪

5~43006.951000.918.15.43554.234.220.0459.6332.726.934~320034.152500.73.450.69360.3231.428.923~236058.853000.833.71.33261.6532.129.552~145088.653500.923.711.67163.3232.530.821~041097.153501.014.371.79065.1132.033.11二、水力计算案例地面高程题目中读取表2干线水力计算管段管长L(m)流量q(L/s)管径D（m）流速υ(m/s)水力坡度1000i水头损失(m)节点水压高程（m）地面高程（m）自由水压（m）①②③④⑤⑥⑦⑧⑨⑩

⑪

5~43006.951000.918.15.43554.234.220.0459.6332.726.934~320034.152500.73.450.69360.3231.428.923~236058.853000.833.71.33261.6532.129.552~145088.653500.923.711.67163.3232.530.821~041097.153501.014.371.79065.1132.033.11二、水力计算案例节点01234567地面高程（m）32.032.532.131.432.734.233．1531．8节点89101112吸水井水塔地面高程（m）32.132.032.332.032.329．032．0第一步：控制点自由水压直接填写要求最低压力20m；第二步：水压高程（9）=地面高程（10）+自由水压20第三步：本管段水压高程（9）43=上管段（9）54+水头损失（7）54第四步：（11）4=（9）4-（10）4表2干线水力计算管段管长L(m)流量q(L/s)管径D（m）流速υ(m/s)水力坡度1000i水头损失(m)节点水压高程（m）地面高程（m）自由水压（m）①②③④⑤⑥⑦⑧⑨⑩

⑪

5~43006.951000.918.15.43554.234.220.0459.6332.726.934~320034.152500.73.450.69360.3231.428.923~236058.853000.833.71.33261.6532.129.552~145088.653500.923.711.67163.3232.530.821~041097.153501.014.371.79065.1132.033.11二、水力计算案例

管网水力计算（支管）某镇给水管网布置及管段长度如图所示。管网最高用水时用水量Qh=97.15L/s，各节点流量标注于图上。各点最小服务水头相同Hc=20m。各点地面高程及吸水井最低水位列于表1。试进行树状网水力计算。树状网水力计算节点01234567地面高程（m）32.032.532.131.432.734.233．1531．8节点89101112吸水井水塔地面高程（m）32.132.032.332.032.329．032．0表1节点地面高程水力计算案例支管水力计算案例管段管长L(m)流量q(L/s)管径D（m）流速υ(m/s)水力坡度i参考水力坡度i水头损失(m)节点水压高程（m）地面高程（m）自由水压（m）①②③④⑤⑥⑦⑧⑨⑩⑪

⑫

1-112002.01000.260.001940.05660.39163.3232.530.821162.9332.030.932-102605.11000.660.01040.0362.70261.6532.129.551058.9532.326.652-124009.91250.830.01170.02344.68261.6532.129.551256.9732.324.673-92502.51000.320.002880.03330.72360.3231.428.92959.632.027.64-616019.41501.120.01610.04052.58459.6332.726.93657.0533.1523.93-737010.31250.850.01220.01394.51360.3231.428.92755.8131.824.017-82202.51000.320.002880.01390.63855.1832.123.08表

支管水力计算管段树状网水力计算支管水力计算案例管段管长L(m)流量q(L/s)管径D（m）流速υ(m/s)水力坡度i参考水力坡度i水头损失(m)节点水压高程（m）地面高程（m）自由水压（m）①②③④⑤⑥⑦⑧⑨⑩⑪

⑫

1-112002.01000.260.001940.05660.39163.3232.530.821162.9332.030.932-102605.11000.660.01040.0362.70261.6532.129.551058.9532.326.652-124009.91250.830.01170.02344.68261.6532.129.551256.9732.324.673-92502.51000.320.002880.03330.72360.3231.428.92959.632.027.64-616019.41501.120.01610.04052.58459.6332.726.93657.0533.1523.93-737010.31250.850.01220.01394.51360.3231.428.92755.8131.824.017-82202.51000.320.002880.01390.63855.1832.123.08表

支管水力计算实际长度树状网水力计算支管水力计算案例管段管长L(m)流量q(L/s)管径D（m）流速υ(m/s)水力坡度i参考水力坡度i水头损失(m)节点水压高程（m）地面高程（m）自由水压（m）①②③④⑤⑥⑦⑧⑨⑩⑪

⑫

1-112002.01000.260.001940.05660.39163.3232.530.821162.9332.030.932-102605.11000.660.01040.0362.70261.6532.129.551058.9532.326.652-124009.91250.830.01170.02344.68261.6532.129.551256.9732.324.673-92502.51000.320.002880.03330.72360.3231.428.92959.632.027.64-616019.41501.120.01610.04052.58459.6332.726.93657.0533.1523.93-737010.31250.850.01220.01394.51360.3231.428.92755.8131.824.017-82202.51000.320.002880.01390.63855.1832.123.08表

支管水力计算根据节点流量计算树状网水力计算支管水力计算案例管段管长L(m)流量q(L/s)管径D（m）流速υ(m/s)水力坡度i参考水力坡度i水头损失(m)节点水压高程（m）地面高程（m）自由水压（m）①②③④⑤⑥⑦⑧⑨⑩⑪

⑫

1-112002.01000.260.001940.05660.39163.3232.530.821162.9332.030.932-102605.11000.660.01040.0362.70261.6532.129.551058.9532.326.652-124009.91250.830.01170.02344.68261.6532.129.551256.9732.324.673-92502.51000.320.002880.03330.72360.3231.428.92959.632.027.64-616019.41501.120.01610.04052.58459.6332.726.93657.0533.1523.93-737010.31250.850.01220.01394.51360.3231.428.92755.8131.824.017-82202.51000.320.002880.01390.63855.1832.123.08表

支管水力计算节点树状网水力计算支管水力计算案例管段管长L(m)流量q(L/s)管径D（m）流速υ(m/s)水力坡度i参考水力坡度i水头损失(m)节点水压高程（m）地面高程（m）自由水压（m）①②③④⑤⑥⑦⑧⑨⑩⑪

⑫

1-112002.01000.260.001940.05660.39163.3232.530.821162.9332.030.932-102605.11000.660.01040.0362.70261.6532.129.551058.9532.326.652-124009.91250.830.01170.02344.68261.6532.129.551256.9732.324.673-92502.51000.320.002880.03330.72360.3231.428.92959.632.027.64-616019.41501.120.01610.04052.58459.6332.726.93657.0533.1523.93-737010.31250.850.01220.01394.51360.3231.428.92755.8131.824.017-82202.51000.320.002880.01390.63855.1832.123.08表

支管水力计算题目中读取节点01234567地面高程（m）32.032.532.131.432.734.233．1531．8节点89101112吸水井水塔地面高程（m）32.132.032.332.032.329．032．0管段管长L(m)流量q(L/s)管径D（m）流速υ(m/s)水力坡度i参考水力坡度i水头损失(m)节点水压高程（m）地面高程（m）自由水压（m）①②③④⑤⑥⑦⑧⑨⑩⑪

⑫

1-112002.01000.260.001940.05660.39163.3232.530.821162.9332.030.932-102605.11000.660.01040.0362.70261.6532.129.551058.9532.326.652-124009.91250.830.01170.02344.68261.6532.129.551256.9732.324.673-92502.51000.320.002880.03330.72360.3231.428.92959.632.027.64-616019.41501.120.01610.04052.58459.6332.726.93657.0533.1523.93-737010.31250.850.01220.01394.51360.3231.428.92755.8131.824.017-82202.51000.320.002880.01390.63855.1832.123.08表

支管水力计算支管属于起点水压已知的管网支管水力计算案例管段管长L(m)流量q(L/s)管径D（m）流速υ(m/s)水力坡度i参考水力坡度i水头损失(m)节点水压高程（m）地面高程（m）自由水压（m）①②③④⑤⑥⑦⑧⑨⑩⑪

⑫

1-112002.01000.260.001940.05660.39163.3232.530.821162.9332.030.932-102605.11000.660.01040.0362.70261.6532.129.551058.9532.326.652-124009.91250.830.01170.02344.68261.6532.129.551256.9732.324.673-92502.51000.320.002880.03330.72360.3231.428.92959.632.027.64-616019.41501.120.01610.04052.58459.6332.726.93657.0533.1523.93-737010.31250.850.01220.01394.51360.3231.428.92755.8131.824.017-82202.51000.320.002880.01390.63855.1832.123.08表

支管水力计算对于起点水压已知的管网，计算时，参考允许的水力坡度确定D和实际水力坡度。例如：管段4～6，末点6最小服务水头20m，则要求的水压高程最小为20+33.15=53.15m，起点4的水压高程为59.63m，则管段4～6允许的最大水头损失为59.63-53.15=6.48m，允许的最大水力坡度为6.48/160=0.0405，将该值填入第7栏参考水力坡度。其它管段以此类推。支管水力计算案例支管水力计算案例管段管长L(m)流量q(L/s)管径D（m）流速υ(m/s)水力坡度i参考水力坡度i水头损失(m)节点水压高程（m）地面高程（m）自由水压（m）①②③④⑤⑥⑦⑧⑨⑩⑪

⑫

1-112002.01000.260.001940.05660.39163.3232.530.821162.9332.030.932-102605.11000.660.01040.0362.70261.6532.129.551058.9532.326.652-124009.91250.830.01170.02344.68261.6532.129.551256.9732.324.673-92502.51000.320.002880.03330.72360.3231.428.92959.632.027.64-616019.41501.120.01610.04052.58459.6332.726.93657.0533.1523.93-737010.31250.850.01220.01394.51360.3231.428.92755.8131.824.017-82202.51000.320.002880.01390.63855.1832.123.08

支管水力计算支管水力计算案例查水力计算表确定管径，并使其对应的水力坡度最接近参考水力坡度而又不大于参考水力坡度。如管段4～6选用150mm管径，流速1.12m/s，已超出经济流速范围，但对应的水力坡度0.0161并未超出参考水力坡度，因此可行。

支管水力计算案例

根据实际水力坡度0.0161求水头损失：h4-6=0.016(i)×160(L)=2.58m，填入第⑧栏；计算末点水压高程：末端水压高程=起端水压高程-管段水头损失6点的水压高程=4点的水压高程（59.63）-h4-6（2.58）=57.05m,填入第⑩6点的自由水压=6点水压高程（57.05）-地面高程（33.15）=23.9m,填入⑫栏。

按照上述方法，管段1～11、3～9、7～8可以选用比100mm更小的管径，但要求干管的最小管径为100mm，故仍选用l00mm管径。支管水力计算案例管段管长L(