DESIGN OF CONVEYANCE CHANNELDesign criteriaPower channel shall be designed as cut and cover type ,square/rectangular inshape and shall be covered by precast concrete sleepers.ReferencesIrrigation and hydraulic structures by S.K.GargTheory and design of hydraulic structures(vol-ii) by R.S.Varshney,S.C.Gupta andR.L.Gupta Code of practice for open power channel IS-7916Code of practice for design of c/s of lined channels IS-4745Design parametersDesign discharge for power generation i/c flushing=2.75cumecsAdd 20% for overrun and seepage losses=0.55cumecsDesign discharge for conveyance channel=3.30cumecsSlope of conveyance channel=0.0025Let d be the minimum depth of water to pass the design dischargethrough the rectangular channel.Taking width of channel as Width = b1.5metersArea =b *d0.72dWetted perimeter =b + 2 d0.72+2dHydraulic radius =(b *d/(b+2*d))^2/3Velocity of flow =V =1/n*r^2/3* s ^1/2Value of n=0.015S = 400v =1.95depthLHSRHSBy trial and error method ,depth of water 1.38/(0.9*d) =1/0.016*(0.5*d/(0.5+2*d)^2/3*(1/450)^1/2)1.131.951.950Width of channel=1.50m1.65Depth of water in the channel=1.20m1.5Velocity of water as per formula =1.95m/secVelocity matches Section is OKgD=3.84Froude No =V/gD0.510.8OK

1.5m1.5mSECTION ADOPTED (1.50MX1.50M)

Chapter -5PRESSURE SHAFTS AND PENSTOCKSEconomic DiameterDesign ParametersLengths of penstocks=Gross Head=146mDesign Net Head=125mEfficiency of Turbine=0.89Design Discharge Q=92.75CumecsRated H P of Turbine P=1000x92.75x125x0.8975137579HPPond Level=1956Centre Line of runner=1799.1Maximum Surge Elevation=1978Temperature variation=15%Mudulus of deformation of rock ( Er )=7.5x104Kg/cm2Poisson's ratio of Rock =0.23Maximum pressure due to water hammer=19.36 mConcreteModulus of elasticity of concrete=0.16 x 106Kg/cm2Possons ratio for concrete=0.2Thickness of concrete around liner=50CmSteelGrade of steel to be used=ASTM A-517 Grade-IModulus of elasticity of steel=2.11 x 10 6Kg/cm2Poisson's Ratio for steel=0.3Coefficient of liner expansion=1.1 x 10 -5per oCMaximum yield stress of steel=690MpaAllowable stress=2100Kg/cm2Joint efficiency=0.95Corrossion allowance=1.5mmSize of stiffeners=16 mm thick x 150 mm wideNormal Spacing=one on every FerruleEconomic Diameter of PenstocksI)G S Sarkaria Farmulaa) D = 0.62 P0.43H0.65D = Diameter of Pressure shaft in m.P = Raterd Horse power of turbineH = Rated head of turbine in m.D = 0.62 (137568)0.43(125)0.65D = 4.95 M b) D = 3.55[ Q2/(2gH)]1/4D = 4.95Average diameter D = 3.85 + 4.952= mii)Fahlbusch FarmulaD = 0.52 H -1/7(P/H)3/7= 0. 52x 125-1/7x [137579/125]3/7= 5.94 miii)USBR FarmulaD = (1.273Q/V)1/2V = 0.125 ( 2 gh)1/2= 0.125*(2*9.81*125)^0.5=6.19miv)Donald's FarmulaD = 0.176 ( P/H)0.466D = 0.176 (137568)0.466(125)0.466D = 5.29 mv)_Empirical FarmulaD = [ 1/910.77 x fOstx K2/k1xQ3/H x t]1/7WhereK 1 = Annualcost of maintenance of penstock per kg= 18 % of Rs 75 = 13.50 per kgOst= Stress in steel = 2100 Kg/ cm2K 2 = Cost per kwh at generator terminal= 2.50f = friction factor = 0.0085t = Annual duration of operation= 365 x 0.502 x 24= 4398 hoursD = [ 1/910.77 x (0.0085)(2100)b2.50/13.50x104.253/273.7x4398]1/7D = 4.882 mVI)Rational Methoda) Cost of excavationArea of excavation /m length=pie/4 (D + D/10x2)2=1.13 D 2Rate of excavation Cost of excavation per m length=1650per cum=1865 D2b) Cost of liningArea of lining = pie [ D + D/10] D/10=0.346 D 2Cost of concrete /cum=3100per cumCost of lining per m length=1073 D2c) Cost of steel liningAverage steel lining thickness PD/2 OstWhereP = Average pressure including water hammer=25.54mO st = Allowable stress in steel=2650 Kg/cm2Average steel lining thick ness=0.0048188 DWeight of liner per m length = pie ( D + 0.0048188) x0.0048188x 7.85=0.1194 D2Cost of liner / m length=0.1194 D 2x 660007880 D 2d) Annual expensesTotal cost = 1865 D 2+ 1073 D 2+ 7880 D 2= 10818 D 2Total cost taking 10 5 overhead charges= 11900 D 2Annual expenses @ 18 % = 2142 D 2e) Power LossHead loss due to friction h f = V 2n2/R4/3 R = Hydraulic Radius=D/4R 4/3 = D 1/3/6.35h f = V2n2 x 6.35 / D 1.33V = Q x 4/ pie D 2V 2 = 1.621 x Q 2D4hf = 10.293x Q2xn2D5.33Substituting for hfPower loss = 9.8 x Q x 0.89 x 10.293 xQ2 x n2D5.33Whereg = efficiency=89%Q = equivalent Discharge=0.55 x 104.2557.34Cumecsn = Coefficient of fricition=0.01Power loss ( unit per year)=9.8 x 0.89 x 10.293 x57.343 x 0.0122D5.33=550176.96D-5..33Power loss ( Rs per year)=550176.963x D-5..33 1650530.89D-5.33f)Total cost (T) = 2142 D 2+ 1650530.89D-5.33g ) Economic diameterFor economic diameter dT/dD=0dT/dD= 2x2142d-5.33x 1650530 D-6.33 = 0 D7.33=5.33x 16505302x2142=4.61mChapter A7SHONG TONG -KARCHAM PROJECTHEAD LOSS IN WATER CONDUCTOR SYSTEM1INTAKE a) Head loss fromTrash rack of intake structure to inlet of HRTh f = kfx(t/b) 1.33 Sin B Vo2/2g ( Kirchemer Farmula)Wherek f = 2.42t = thickness of rack bar= 10 mm = 0.01 mb = clear spacing between bars= 7.62 mmV o =Velocity through racks = 1 m /sec ( FRL condition=1 m /sec ( FRL conditionh f = 2.42x(0.4/3) 1.33 Sin 90x (3.11)2/2x9.81=0.07mb) Loss at entrancehe = kl V2/2gWherekl = 0.1 for rounded entrance=0.1 x 7.95 ^2/(2 x9.8100.32m2Head loss through approach tunnela) Head loss in tunnelhf =n2V2 LR4/3=0.015^2x221^2x4.01^2x2212.5 ^(4/3)0.24mb) Head loss due to bendhe = kl V2/2gWherekl = depends upon ratio d/Dfor 63 o bend , kb = 0.019=0.19 x 4.50 ^2/(2 x9.8100.2m2SEDIMENTATION CHAMBERa) Head loss in chamberLength of sedimentation chamber=300mArea of sedimentation chamber=204m2Perimeter of sedimentation chamber=55mHydraulic radius=3.4mHead Loss=n2V2 LR4/3=0mb) Head loss due to expansionHead loss due to gradual enlargement in inlet transition' henl'=f( V12-V12)2gWheref = empirical coefficient depending upon O0 = double the angle between axis of pipe and its sidetan o/2= 5.5 o , O = 11 of = 0.09 ( corresponding to ) = 11ohenl =0.09(5^2-0.3^2)2x9.810mc) Head loss due to contractionhc =(1/c-1)2x V2/2gWhereV = Velocity in smaller pipec = ratio of smaller to larger diameterhc =(1/c-1)2x 0.32/29.810.3m3Head Loss in HRTa) Head Loss due to friciton=n2V2 LR4/3Length of Head Race Tunnel=8020mArea of HRT=78.55m^2Hydraulic radius R = A/P=2.5mb) Head loss due to bendhe = kl V2/2gWherekl = depends upon ratio d/Dfor 63 o bend , kb = 0.019=0.19 x 4.50 ^2/(2 x9.8100.2m4Pressure shaftDiameter of Pressure shaftVelocity through pressure shaftsContraction losses=f( V12-V12)2gBend losseshe = kl V2/2gWherekl = 0.1 for rounded entrance=0.1 x 7.95 ^2/(2 x9.8100.32mFriction Head loss=n2V2 LR4/3TAIL RACE TUNNELLength of TRTArea of TRTR = A/PVelocityFrictional Head Loss=n2V2 LR4/3Ben lossesTotal Head loss1Intake2Approach tunnels3Sedimentation chamber4Head race Tunnel5Pressure shaft6Tail Race Tunnel

???Page ??? (???)01/12/2015, 16:25:24Page / TANGER CHANJU SHEP (4.80 MW)GAJ GAJEHU SHEP(5MW)M/s Capital ConsortiumHydraulic Design of Trench Weir IntakeHydraulic Design of Trench Weir IntakeHydraulic Design of Trench Weir IntakeHydraulic Design of Trench Weir Intake