西苕溪水资源开发课程设计任务书

'西苕溪水资源开发课程设计任务书一、设计任务4二、基本资料42.1流域及水库情况简介42.2水文气象资料52.3设计资料5三、设计年径流及其分配63.1设计年径流量计算63.2设计年径流量及其年内分配8四、水库死水位及正常蓄水位选择84.1兴利库容计算84.2死水位选择84.3正常蓄水位的选择9五、装机容量及多年平均发电量95.1代表年的水能计算95.2死水位优化115.3装机容量与装机台数选择125.4水能指标确认15六、设计洪水过程线推求15 6.1资料三性检查及攒展延洪水系列156.2设计洪峰流量计算176.3设计洪水过程线推求20七、水库防洪特征水位及坝顶高程计算247.1调洪规则及起调水位247.2防洪高水位计算247.3设计洪水位计算287.4校核洪水位计算317.5坝顶高程选择34八、结论358.1水库有关特征参数选择358.2调洪有关特征参数选择358.3水电站有关特征参数358.4感言36九、附录36一、设计任务在太湖流域的西苕溪支流西溪上,拟修建一水库,因而要进行水库规划的水文水利计算,其具体任务是:1.设计年径流及其年内分配2.选择水库死水位。3.选择正常蓄水位。4.计算保证出力和多年平均发电量。 5.选择水电站装机容量。6.推求各种洪水特征水位和确定大坝高程。二、基本资料2.1流域及水库情况简介西苕溪为太湖流域一大水系,流域面积为2260km2,发源于浙江省安吉县天目山,干流全长150km,上游坡陡流急,安城以下堰塘遍布,河道曲折,排泄不畅,易遭洪涝灾害,又因流域拦蓄工程较少,灌溉水源不足,易受旱灾。该水库为根治西苕溪流域水旱灾害骨干工程之一,控制西苕溪主要支流西溪,坝址以上流域面积328km2。流域内气候温和、湿润、多年平均雨量孝丰站为1450mm,国民经济以农、林业为主,流域内大部为山区,小部为丘陵,平地较少。流域水系及测站分布见下图1。水库以防洪为主,结合发电、灌溉、航运及水产,是一座综合利用水库。2.2水文气象资料流域内有三个雨量站,分别从1956年、1961年和1962年开始观测到今。在坝址下游1公里处设有水文站,自1954年开始有观测的流量资料。通过频率计算,得各设计频率的设计年径流量,选择典型年,计算缩放倍比。根据调查1922年9月1日在坝址附近发生一场大洪水,推算得水文站洪峰流量为1350m3/s。这场洪水是发生后至今最大的一次洪水。缺测年份内,没有大于1160m3/s的洪水发生。2.3设计资料 1、在本地区的兴利要求中,灌溉及航运任务不大,均可利用发电尾水得到满足,因此,本地区的兴利要求调节流量不低于5m3/s,设计保证率为85%。2、工程设计标准理论上应根据工程规模和重要程度查工程手册确定,在此次课程设计中简化处理为直接给出,确定该水库为大(2)型水库,工程等别为Ⅱ等,永久性水工建筑级别为2级。下游防洪标准为5%,水库设计标准为1%,校核标准为0.2%。3、水库水位库容曲线如图2所示:4.水电站下游水位流量关系曲线如图3所示:5.根据泄洪建筑物型式尺寸,可计算得泄流曲线如表1所示:水位(m)zZ+1Z+2Z+3Z+4Z+5流量(m3/s)332336341347351354水位(m)Z+6Z+7Z+8Z+9Z+10Z+11流量(m3/s)3583623704818741460三、设计年径流及其分配3.1设计年径流量计算对水库历年来水量进行分析,选择水文年为四月份到次年的三月份。计算各水文年的年平均来水量,将各水文年的年平均来水量按从大到小的顺序排列并进行频率计算,计算结果见表2:使用软件绘制频率曲线如下图4:由上图的频率曲线得出:枯水年P85%,14.2m3/s 中水年P50%,18.9m3/s丰水年P15%,25.8m3/s3.2设计年径流量及其年内分配结合各保证率下的平均来水量及水文年选取1996-1997年为符合设计保证率的丰水年、1979-1980年为符合设计保证率的枯水年、1984-1985年为符合设计保证率的中水年。根据实际年的年内各月流量,以代表年的年水量为控制,按年水量的比值进行缩放,求得代表年的各月平均流量计算结果见表3:四、水库死水位及正常蓄水位选择4.1兴利库容计算兴利调节计算的基本依据是水库的水量平衡原理,将调节周期划分为若干个时段(以月计),按照时历列表法进行兴利调节计算,调节流量Q调5m3/s,调节计算过程见附表3:由表可知兴利库容V兴25.63(106m3)。库容系数得β25.63/634.6034.03%,则该水库属于不完全年调节水库。4.2死水位选择根据水库泥沙淤积计算死水位由下面两个公式其中:W0??年平均径流总量m??泥沙沉积率P??孔隙率ρ0??多年平均含沙量 γ??泥沙干容重α??推移质与悬移质淤积量之比Tn??水库使用年限将ρ00.237kg/m3,γ1650kg/m3,m90%,p0.3,α15%,T100,W0634.603106m3等值代入上述两个公式,可得:Vn134774.9m3/year,Vs13.5(106m3,查库容曲线可得Z62.75m,在此基础上再加2米为64.75米,则h淤积死64.75(m。根据水轮机运行允许的最低水头计算死水位本省生产的水轮机机型有HL263-LJ-100(即混流式263型,主轴金属锅壳,转轮直径1米),单机容量为1250千瓦,适应最小水头为16m。水轮机要求上游最小水位=16+下游水位+水头损失0.5,由调节流量Q5m3/s查下游水位流量关系曲线的Z下46.476m,得水轮机要求上游最小水位Z死62.976m。综合各方面的情况,最终选定h死(h淤积,死,h水轮机,死)64.75m。4.3正常蓄水位的选择正常高水位下的库容兴利库容+死库容查库容曲线可得死库容为17.5(106m3),则正常高水位下的库容为43.13(106m3)再一次查库容曲线可得正常高水位为71.51m五、装机容量及多年平均发电量5.1代表年的水能计算由水力发电原理得水能计算公式如下 按等流量调节方式计算各时期的引用流量,计算公式如下:由已知条件ΔH0.5m,K7.5,V兴25.63(106m3)可得:枯水年:供水期为10月到次年2月及4月共六个月,其调节流量为Q引4.86m3/s;蓄水期为6月,其调节流量为Q引``42.525m3/s,其余月份为不蓄不供期。丰水年:供水期为4月、12月、1月,其调节流量为Q引10.068m3/s;蓄水期为7月,其调节流量为Q引``81.37m3/s,其余月份为不蓄不供期。中水年:供水期为11月、1月、2月、3月,其调节流量为Q引10.089m3/s;蓄水期为6月、7月,其调节流量为Q引``37.657m3/s,其余月份为不蓄不供期。根据等流量调节方式进行水能计算过程见表4:5.2死水位优化由水能计算表可看出在丰水年的6月平均水头未达到16m,因此需要进行死水位的优化,将本月的平均水头设为16m,可通过反推计算求得V死18.5(106m3),H死65.13m则正常高水位下的库容为44.13(106m3),正常高水位为71.71m,用所得死库容进行等流量调节水能计算可得死水位优化后的等流量调节方式水能计算表,见表5:5.3装机容量与装机台数选择通过水能计算表的结果,以各级流量相应的出力为统计对象,由大到小排序,用经验频率公式,计算相应的频率,由此可以绘制出日平均出力经验频率曲线N-P,如图5所示;根据水电站选定的设计保证率P0,可以在该曲线上查取水电站保证出力Np,将保证率P100%改成一年的持续时间T8760h,则任一保证率Pi相应的持续时间为h,于是得到持续时间坐标Th, 由此便可以将水流出力保证率曲线变换为水流出力持续曲线N-T,如图6所示;将出力划分成若干分段,然后计算相应分段的面积即电量,且自下而上得到电量累计值,最后以出力值为纵坐标,电量累计值为横坐标即可绘制成N-E曲线,如图7所示:电量计算过程:见表6:图5::月平均出力经验频率曲线图6:出力持续曲线图7:月平均出力发电量曲线由丰、中、枯三个代表年的水流出力(无装机容量限制)可求得多年平均发电量为2681.98万kw?h,由已知条件可知年装机利用小时数为3440h。根据公式,可初步确定装机容量为7796(KW),本省生产的水轮机机型有HL263-LJ-100(即混流式263型,主轴金属锅壳,转轮直径1米),单机容量为1250千瓦,所以可以确定机组台数为7台,所以最终确定该水电站的总装机容量为8750KW。如表7所示:5.4水能指标确认A保证出力计算对设计枯水年进行水能计算,该年供水期的平均出力,即为水电站保证出力。根据表4,水电站在设计枯水年供水期10月至次年2月和4月共六个月的总出力为4630.86KW,则水电站保证出力为771.81KW。B多年平均发电量校核在选定水电站装机容量为8750KW后,在如图7所示的N-T曲线上按“装机切头”去掉超过装机容量的那部分水流出力,求得装机容量线以下出力持续曲线所包围的面积,即水电站多年平均发电量为2624.295(kw?h)。 六、设计洪水过程线推求6.1资料三性检查及攒展延洪水系列该水库原设计采用雨量资料推求设计洪水,现采用流量资料来推求设计洪水,且资料具有一定的可靠性;且资料记载的这些洪水是在一致的流域下垫面和气候条件下形成的,即各洪水形成的基本条件未发生显著改变,说明此洪水资料符合一致性;该洪水系列较长,并且包括大、中、小等各种洪水,则推断该系列代表性较好。将所给的典型洪水过程的一天洪量和七天洪量相关,三天洪量和七天洪量相关,比较其相关性,分别如图8、9所示图8:天洪量和七天洪量相关图图9:三天洪量和七天洪量相关图由上图可知七天洪量和三天洪量的相关性较好,因此选用七天和三天洪量的相关关系对七天洪量进行插补延长可得典型年的七天洪量结果如表8所示:年份24小时洪量W(106m3)三天洪量W(106m3)七开洪量W(106m3)插补七天洪量195427.9458.469.3619558.1713.320.75195629.83645.22195722.837.1952.4619588.7215.8522.15195911.1319.832.9196015.720.833.2 196152.579.188.2196243.749.253.1196355.686.695.9196414.3231.740.7196515.6224.42719669.51425.4196711.82192819689.918.435.5196920.932.848.4197017.231.935.6197123.431.835.319725.3410.212.23197319.8742.8552.60197416.1639.0548.50197511.5822.0530.1819768.2919.9527.9219777.6120.4528.466.2设计洪峰流量计算将实测资料由大到小排列,计算各项的经验频率,使用绘图软件绘制频率曲线,年最大洪峰流量、最大一天洪量、最大三天洪量以及最大七天洪量的频率曲线如图10、11、12、13所示:图10:年最大洪峰流量频率曲线 图11:最大一天洪量频率曲线图12:最大三天洪量频率曲线图13:最大七天洪量频率曲线6.3设计洪水过程线推求设计洪水过程线是指具有某一设计标准的洪水过程线。为了适应工程设计要求,目前采用放大典型年洪水过程线的方法,使设计过程线的洪峰流量和时段洪水总量的数值等于设计值,其出线的频率等于设计标准,即认为所得的过程线是待求的设计洪水过程线。应用同频率放大法,采用长包短方式,根据设计洪水洪量、洪峰流量和典型洪水洪量、洪峰流量求得相应的放大比例,其放大倍比的公式如下:由典型洪水过程线得其洪峰、最大24小时洪量、最大三天洪量、最大七天洪量QMD1160m3/s,最大24小时:W1D55.6(106m3)最大三天洪量为86.6(106m3),最大七天洪量为95.9(106m3),设计标准P0.2%,1%,5%,按同频率放大法计算的结果见表9:由以上所求的放大倍比,结合所给的典型年的洪水过程进行放大,可求得不同频率下的洪水过程线如图14所示:计算过程见表10:时段典型洪水流量m3/s缩放比0.2%标准缩放修匀后缩放比1%标准缩放修匀后缩放比5%标准缩放修匀后061.8811.3011.301.458.698.691.016.056.05171.8813.1913.191.4510.1410.141.017.067.06 271.8813.1913.191.4510.1410.141.017.067.06381.8815.0715.071.4511.5911.591.018.078.074151.8828.2628.261.4521.7421.741.0115.1215.125231.8843.3443.341.4533.3333.331.0123.1923.196341.8864.0664.331.4549.2747.941.0134.2831.747431.8981.3681.021.4160.6362.310.9340.1443.358571.89107.85107.851.4180.3780.370.9353.2253.229731.89138.12138.121.41102.93102.930.9368.1568.15101001.89189.20189.201.41141.00141.000.9393.3693.36111301.89245.96245.961.41183.31183.310.93121.37121.37121711.89323.54323.541.41241.12241.120.93159.65159.65 132301.89435.17435.171.41324.31324.310.93214.73214.73142601.89491.93491.931.41366.61366.610.93242.74242.74153171.89599.77599.771.41446.98446.980.93295.95295.95163351.89633.83633.831.41472.37472.370.93312.76312.76173621.89684.92706.941.41510.44519.630.93337.96335.89183731.95728.42705.731.44535.42525.950.93346.10348.23193501.95683.51683.511.44502.40502.400.93324.76324.76203301.95644.45644.451.44473.69473.690.93306.20306.20213151.95615.16615.161.44452.16452.160.93292.28292.28223051.95595.63595.631.44437.81437.810.93283.00283.00232931.95572.19572.191.44420.58420.580.93271.87271.87 242931.95572.19572.191.44420.58420.580.93271.87271.87254451.95869.03869.031.44638.77638.770.93412.91412.91265751.951122.901122.91.44825.37825.370.93533.53533.53276751.951318.191318.21.44968.92968.920.93626.32626.32288051.951572.071572.11.441155.51155.50.93746.94746.94299151.951786.881786.91.441313.41313.40.93849.01849.013010001.951952.881952.91.441435.41435.40.93927.88927.883110601.952070.052070.11.441521.61521.60.93983.55983.553211301.952206.752206.81.441622.01622.00.931048.51048.53311601.732001.272101.31.311523.41573.40.901038.51038.53410601.952070.051970.11.441521.61471.60.93983.55983.55 359501.951855.231855.21.441363.71363.70.93881.48881.48368641.951687.291687.31.441240.21240.20.93801.69801.69377601.951484.191484.21.441090.91090.90.93705.19705.19386601.951288.901288.91.44947.38947.380.93612.40612.40396171.951204.931204.91.44885.66885.660.93572.50572.50404701.95917.85917.851.44674.65674.650.93436.10436.10413701.95722.56700.051.44531.11521.720.93343.31345.43423061.89578.96597.581.41431.47439.240.93285.68285.68432601.89491.93491.931.41366.61366.610.93242.74242.74442351.89444.63444.631.41331.36331.360.93219.40219.40452271.89429.49429.491.41320.08320.080.93211.93211.93 462401.89454.09454.091.41338.41338.410.93224.06224.06472531.89478.68478.681.41356.74356.740.93236.20236.20482691.89508.96508.961.41379.30379.300.93251.14251.14492771.89524.09524.091.41390.58390.580.93258.61258.61502861.89541.12541.121.41403.27403.270.93267.01267.01512951.89558.15558.151.41415.96415.960.93275.41275.41522901.89548.69538.691.41408.91403.910.93270.74270.74532631.89497.60517.601.41370.84380.840.93245.54245.54542771.89524.09514.091.41390.58385.580.93258.61258.61552651.89501.39501.391.41373.66373.660.93247.40247.40562521.89476.79476.791.41355.33355.330.93235.27235.27 572451.89463.55463.551.41345.46345.460.93228.73228.73582351.89444.63444.631.41331.36331.360.93219.40219.40592241.89423.82423.821.41315.85315.850.93209.13209.13602121.89401.11401.111.41298.93298.930.93197.92197.92612051.89387.87387.871.41289.06289.060.93191.39191.39621921.89363.27363.271.41270.73270.730.93179.25179.25631801.89340.57340.571.41253.81253.810.93168.05168.05641611.89304.62304.621.41227.02227.020.93150.31150.31651551.89293.27293.271.41218.56218.560.93144.71144.71661451.89274.34274.341.41204.46204.460.93135.37135.37671301.89245.96245.961.41183.31183.310.93121.37121.37 681181.89223.26223.261.41166.39166.390.93110.17110.17691181.89223.26223.261.41166.39166.390.93110.17110.17701031.89194.88194.881.41145.23145.230.9396.1696.1671971.89183.53183.531.41136.77136.770.9390.5690.5672921.89174.07174.071.41129.72129.720.9385.8985.8973851.89160.82160.821.41119.85119.850.9379.3679.3674821.89155.15155.151.41115.62115.620.9376.5676.5675791.89149.47149.471.41111.39111.390.9373.7573.7576651.89122.98122.981.4191.6591.650.9360.6860.6877551.89104.06104.061.4177.5577.550.9351.3551.3578431.8981.3681.021.4160.6362.310.9340.1443.35 79411.8877.2577.571.4559.4157.811.0141.3338.2880331.8862.1862.181.4547.8247.821.0133.2733.2781361.8867.8367.831.4552.1752.171.0136.2936.2982431.8881.0281.021.4562.3162.311.0143.3543.3583491.8892.3292.321.4571.0171.011.0149.4049.4084531.8899.8699.861.4576.8076.801.0153.4353.4385501.8894.2194.211.4572.4672.461.0150.4150.4186481.8890.4490.441.4569.5669.561.0148.3948.3987471.8888.5688.561.4568.1168.111.0147.3847.3888461.8886.6786.671.4566.6666.661.0146.3746.3789441.8882.9082.901.4563.7663.761.0144.3644.36 90431.8881.0281.021.4562.3162.311.0143.3543.3591411.8877.2577.251.4559.4159.411.0141.3341.3392391.8873.4873.481.4556.5256.521.0139.3239.3293371.8869.7169.711.4553.6253.621.0137.3037.3094351.8865.9565.951.4550.7250.721.0135.2835.2895341.8864.0664.061.4549.2749.271.0134.2834.2896331.8862.1862.181.4547.8247.821.0133.2733.2797321.8860.2960.291.4546.3746.371.0132.2632.2698311.8858.4158.411.4544.9244.921.0131.2531.2599301.8856.5256.521.4543.4743.471.0130.2430.24七、水库防洪特征水位及坝顶高程计算7.1调洪规则及起调水位 调洪规则对不超过下游设计标准的洪水,从防洪限制水位开始,根据水库下游防洪要求,来多少泄多少,但不超过下游安全流量调节流量+100。对不超过水库设计标准的洪水,从防洪限制水位开始,先参考第二条。待蓄至防洪高水位后,即打开溢洪道闸门和泄洪洞闸门,自由泄流。对不超过水库效核标准的洪水,从防洪限制水位开始,先参考第三条。待蓄至设计洪水位后,再加开非常泄洪道100m3/s。起调水位起调水位(防洪限制水位)=正常蓄水位-1m=71.71-1=70.71m。7.2防洪高水位计算根据调洪规则,当水库遭遇下游设计标准的洪水时,从防洪限制水位70.71m开始,根据水库下游防洪要求,来多少泄多少,当来流量大于下游安全流量105m3/s时,则按下游安全泄量下泄,直到来水量与下泄量相等时水库达到最高水位,此时的水位即为防洪高水位,对应的下泄流量为最大下泄流量,防洪高水位与防洪限制水位之间的库容即为防洪库容。按照此规则对P5%的洪水进行调洪演算,可得防洪高水位为80.2796m,此时达到的最大泄量为105m3/s,用防洪高水位所对应的库容减去防洪限制水位所对应的库容得到水库的防洪库容为57.5(106m3。计算过程见表11:时段QqVZ06.056.0539.193270.7117.067.0639.193270.7127.067.0639.193270.71 38.078.0739.193270.71415.1215.1239.193270.71523.1923.1939.193270.71631.7431.7439.193270.71743.3543.3539.193270.71853.2253.2239.193270.71968.1568.1539.193270.711093.3693.3639.193270.7111121.3710539.222770.71612159.6510539.350570.74213214.7310539.646470.802114242.7410540.091870.892615295.9510540.683571.012916312.7610541.401271.158817335.8910542.190771.319318348.2310543.044171.492719324.7610543.877571.662120306.210544.635271.816121292.2810545.334571.95822228310545.99272.091923271.8710546.612872.21824271.8710547.213572.3401 25412.9110548.068172.513826533.5310549.393772.783327626.3210551.103473.130828746.9410553.197373.556429849.0110555.69274.063430927.8810558.512474.636731983.5510561.57575.1869321048.510564.854775.6678331038.5410568.233476.163234983.5510571.495176.641535881.4810574.474277.078336801.6910577.125977.467137705.1910579.460377.809438612.410581.453978.101739572.510583.208778.359140436.110584.646278.569841345.4310585.67578.720742285.6810586.43378.831843242.7410587.006178.915944219.410587.4678.982445211.9310587.858479.040846224.0610588.265279.1005 47236.210588.715679.166548251.1410589.214879.239749258.6110589.754479.318850267.0110590.322579.402151275.4110590.920979.489952270.7410591.525979.578653245.5410592.077279.659454258.6110592.606779.737155247.410593.139579.815256235.2710593.630379.887157228.7310594.087579.954258219.410594.516280.013859209.1310594.909580.060760197.9210595.264280.102961191.3910595.58780.141362179.2510595.876180.175763168.0510596.123380.205164150.3110596.318380.228465144.7110596.471380.246666135.3710596.597580.261667121.3710596.681680.271668110.1710596.720480.2762 69110.1710596.73980.27857096.1696.1696.748380.27967190.5690.5696.748380.27967285.8985.8996.748380.27967379.3679.3696.748380.27967476.5676.5696.748380.27967573.7573.7596.748380.27967660.6860.6896.748380.27967751.3551.3596.748380.27967843.3543.3596.748380.27967938.2838.2896.748380.27968033.2733.2796.748380.27968136.2936.2996.748380.27968243.3543.3596.748380.27968349.449.496.748380.27968453.4353.4396.748380.27968550.4150.4196.748380.27968648.3948.3996.748380.27968747.3847.3896.748380.27968846.3746.3796.748380.27968944.3644.3696.748380.27969043.3543.3596.748380.2796 9141.3341.3396.748380.27969239.3239.3296.748380.27969337.337.396.748380.27969435.2835.2896.748380.27969534.2834.2896.748380.27969633.2733.2796.748380.27969732.2632.2696.748380.27969831.2531.2596.748380.27969930.2430.2496.748380.2796流量:下泄过程及水位变化过程如图15所示:7.3设计洪水位计算根据调洪规则,当水库遭遇设计标准的洪水时,从防洪限制水位70.71m开始,根据水库下游防洪要求,来多少泄多少,当来流量大于下游安全流量105m3/s时,则按下游安全泄量下泄,待蓄至防洪高水位后,即打开溢洪道闸门和泄洪洞闸门自由泄流,此情况下所对应的坝前最高水位即为设计洪水位,对应的下泄流量为最大下泄流量,设计洪水位与防洪限制水位之间的库容即为拦洪库容。按照此规则对P0.5%的洪水进行调洪演算,可得到设计洪水位为80.9157m,此时达到的最大泄量为994.544m3/s,用设计洪水位所对应的库容减去防洪限制水位所对应的库容得到水库的拦洪库容为62.9(106m3。计算过程见表12:时段QqVZ08.698.6939.193270.71110.1410.1439.193270.71 210.1410.1439.193270.71311.5911.5939.193270.71421.7421.7439.193270.71533.3333.3339.193270.71647.9447.9439.193270.71762.3162.3139.193270.71880.3780.3739.193270.719102.93102.9339.193270.711014110539.25870.723211183.3110539.463870.76512241.1210539.849770.843413324.3110540.489570.973514366.6110541.355271.149415446.9810542.441671.370216472.3710543.718571.629817519.6310545.126171.915918525.9510546.630172.221619502.410548.103172.52120473.6910549.482172.801221452.1610550.770673.063122437.8110551.994673.311923420.5810553.161773.5491 24420.5810554.297873.7825638.7710555.826674.090826825.3710558.08474.549627968.9210560.935875.0932281155.5210564.381875.5985291313.4210568.447876.1947301435.4310573.017876.8648311521.5610577.962477.5898321622.0410583.242878.3641331573.410588.616679.152341471.5610593.719679.9002351363.6610598.44580.4815361240.21936.326101.25880.8164371090.93987.475101.99180.903738947.38994.544102.09280.915739885.66977.135101.84380.88640674.65933.184101.21280.81141521.72863.165100.13380.682442439.24803.71698.861980.531243366.61741.45597.531180.372844331.36680.48796.22880.217645320.08625.37695.0580.0774 46338.41576.09894.072679.95247356.74533.14793.327279.842748379.3502.11192.788779.763749390.58480.7292.405379.7075'