voulume iii - technical annex
TRANSCRIPT
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Nyadi Hydropower Project
Feasibility StudyFinal Report
Volume III Technical Annex
October, 2010
Appendix D Design calculation
Appendix E Optimization study
Appendix F Cost estimate and financial
AnalysisAppendix G Access road design report
Appendix H Photographs
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Nyadi Hydropower Limited (NHL)
Nyadi Hydropower ProjectFeasibility Study
Final Report
Volume III Technical Annex
October, 2010
Nyadi Hydropower Limited (NHL)
Quality control Signature Date
Prepared by: Basanta Bagale
Lochan Devkota
Sumin Shrestha
Basanta M. Shrestha
Uttam Dhakal
Checked by: Saroj Lal Shrestha
Approved by: Bharat Raj Pandey
Appendix D Design calculation
Appendix E Optimization study
Appendix F Cost estimate and financial
Analysis
Appendix G Access road design report
Appendix H Photographs
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Report Contents
EXECUTIVE SUMMARY
VOLUME 1 MAIN REPORT
VOLUME 2 INVESTIGATION ANNEX
APPENDIX A HYDROLOGY AND SEDIMENTOLGY
APPENDIX B TOPOGRAPHICAL SURVEY
APPENDIX C SITE INVESTIGATION (GEOLOGY AND
GEOTECHNICAL
VOLUME 3 TECHNICAL ANNEX
APPENDIX D DESIGN CALCULATION
APPENDIX E OPTIMIZATION STUDY
APPENDIX F COST ESTIMATE AND FINANCIALANALYSIS
APPENDIX G ACCESS ROAD DESIGN REPORT
APPENDIX H PHOTOGRAPHS
VOLUME 4 MAP AND DRAWINGS
APPENDIX J TOPOGRAPHICAL MAPSAPPENDIX K GEOLOGICAL MAPS
APPENDIX L CIVIL DRAWIGS
APPENDIX M ELECTRICAL DRAWINGS
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Hydro Consult Nyadi Hydropower Project
Feasibility Study Volume III
Nyadi Hydropower Limited
APPENDIX D
DESIGN CALCULATION
NYADI HYDROPOWER PROJECT
FEASIBILITY STUDY
October, 2010
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HYDRAULIC DESIGN
Weir Hydraulics
Orifice Design
Settling Basin Design
Penstock Design
Anchor Block Design
Surge Tank Design
Headloss Calculation Sheet
Power and Output Energy Calculation
HEC RAS Result
Turbine Design Calculation
Tailrace Tunnel Design
Level Determination of Powerhouse and tailrace
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Weir Hydraulics
Calculation of U/S and D/S cutoffs, and Uplift Pressures
Discharge (100 yrs flood) m3/sec 509.00
Length of weir m 14.00
Weir crest elevation masl 1381.50
Coefficient of discharge Cd 2.10
Length of U/S floor m 26.50
Length of sloping glacies m 10.21Length of D/S floor (S tilling basin) m 21.00
Total floor length b m 57.71
Head over the crest m 6.69
U/S TEL masl 1388.19
Water level elevation U/S of the weir can be determined using the Bernoulli's equation and iteration
NOTE : The design of the Headworks Weir Arrangment has been done on the basis of Hydraulic Model Studies carried out at Hydro Lab Pvt Ltd. The detailed information
about the study result has been compiled on Hydraulic Model Study of the Headworks of Nyadi Hydropower Project.
Weir
8.000
12.000
21.00
10.21
26.50
2/3CLHQ =
U/S bed level m 1372.90
U/S total energy Ec m 15.29
Water depth m 14.93
U/S water level elevation (HGLu) 1372.9+14.93 m 1387.83
Free Board m 0.87
Guide wall Crest Elevation masl 1388.70
Depths of cutoffs
Scour depth U/S and D/S of the floor is determined by Newzealand Formula.
[Equation provided by Bharat Raj Pandey and used in Marsyangdi-III Hydroelectric Project (MHEP-III)]
Discharge intensity q m3/s/m 36.36
U/S Water Depth Y m 14.93
Velocity of Flow V m/s 2.66
Cross Sectional Area of Flow A m 209.04
Width of Flow B m 14.00
Constant k 0.62
Scour Depth measured from HFL dS =k.Y.V.B/A m 6.38
Depth of U/S cutoff below the U/S HFL =1.25 ds m 7.97
Level of bottom of U/S cutoff 1387.83-7.97 m 1379.86
Therefore, U/S cutoff depth below U/S floor 1371.5-1379.86 m -8.36 Cutoff Not Necessary
Provided U/S cutoff depth m 8.00 ADOPT
D/S water Elevationmasl
1378.07
Result from HECRAS Analysis -
WSE at RS 18 (Chainage 0+160)
Depth of D/S cutoff below the D/S HFL =1.50 ds m 9.57
Level of bottom of D/S cutoff 1378.07-9.57 m 1365.46
Therefore, D/S cutoff depth m 3.54 Cutoff Required
Provided D/S cutoff depth m 6.00 ADOPT
Uplift Pressures
U/S floor elevation masl 1371.50
D/S floor (basin) elevation masl 1369.00
Length of U/S cutoff m 8.00
Length of D/S cutoff m 6.00
)(2 11
yEg
qy
o
=
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U/S Cutoff Elevation masl 1363.50
D/S Cutoff Elevation masl 1363.00
D/S Curtain Grouting Depth m 6.00
[Reference: DWPF page no. 74 & 75 (Case 4 and Case 5) and table VII-5 of page no. 100]
Check for Thickness
For 100 yrs flood
U/S portion upto the just below the orifice
Total downstream forces acting (F1) = Weight of water over the concrete + Weight of the concrete
HFL Low Flow
Assume thickness 2.2 m 2 m
Upward force (uplift pressure) 160.20938 KN/m2 122.625 KN/m2
Downward force (weight of concrete +Weight of water) 213.00938 KN/m2 170.625 KN/m2
Factor of saftey 1.330 ok 1.400 ok
U/S portion upto sloping portion starting from just below the orifice
Total downstream forces acting (F1) = Weight of water over the concrete + Weight of the concrete
HFL Low Flow
Assume thickness 2.2 m 2.6 m
Upward force (uplift pressure) 160.20938 KN/m2 122.625 KN/m2
Downward force (weight of concrete +Weight of water) 213.00938 KN/m2 160.5 KN/m2
Factor of saftey 1.330 ok 1.310 ok
sloping portion
Total downstream forces acting (F1) = Weight of water over the concrete + Weight of the concrete
HFL Low Flow
Assume thickness 3 m 2.8 m
. .
Downward force (weight of concrete +Weight of water) 211.2272 KN/m2 206.4272 KN/m2
Factor of saftey 1.320 ok 1.490 ok
Stilling Basin
Total downstream forces acting (F1) = Weight of water over the concrete + Weight of the concrete
HFL Low Flow
Assume thickness 3.2 m 3.2 mUpward force (uplift pressure) 160.20938 KN/m2 160.20938 KN/m2
Downward force (weight of concrete +Weight of water) 216.0272 KN/m2 216.0272 KN/m2
Factor of saftey 1.350 ok 1.350 ok
note: this thickness can reduced gardually upto 1.5m
Check for exit gradient
Normal flow condition Flood flow condition
Seepage head 12.500 9.761
Depth of central cutoff (assume)
Intermediate cutoff
length of weir section 57.710 57.710
Total floor length (creep length) b 97.710 97.710
a =b/d 8.143 8.143
4.602 4.602
Permissible exit gradient GE per =1/6 0.167 0.167
Exit Gradient GE 0.155 0.121
OK OK
For Added Safety
Provide the drainage hole of dia 0.15m at 2.8m C/C throught the section
2
11 2
++
=
=
1
d
hEG
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Date
Job :
Job No:
Calculated by:
Design Considerations/Assumptions Checked by:
1. The intake opening will be submerged orifice, and may be open during full flushing
2. The orifice will be above river bed level to exclude bigger sediment
3. The top level of the orifice will be just below normal water level so that floatinig debris can be excluded,4. The design discharge is 11.08 m3/sec
5.
6. 20% of the design discharge is taken as Flushing discharge at gravel trap and settling basin during the period of continuous flushing
7. Normal water level 1381.5 m
8. River bed level at intake is taken as 1371.6
9. During high flood condition the radial gate will open accordingly
1 Input Data
Percentage Exceedence ~40 %
Design turbine discharge (Qpower) = 11.08 m3/sec
Gravel Flushing Discharge (QSF) = 10%
Sediment Flushing discharge (Qb) = 10%
Set Velocity (V) = 0.60 m/s
Orifice height/depth (H) = assumed 3.50 m
No of bay 3 nos
Central pier thickness (t) 0.50 m
Each bar thickness 0.01 mSpacing of each bar 0.25 m
Width of orifice provided (B)= 2.25 m
Normal Water level (NWL)= 1381.5 m
Invert level of orifice 1376.5 m Plan sketch
Discharge coffiecient (c) = 0.60 for roughly finished masonary
orifice
Accleration due to ravit = 9 81 2
ORIFICE DESIGN-1
Velocity will be limited to 0.5 to 1.1 m/s during normal flow conditions for the exclusion of bed load and floating load to remain at the trash rack (Ref: Emile Mosony 2/A)
I:\ED\Jobs\OPEN\751220 Nyadi Implementation\03Reports\Final Review 30 MW as per Damodar Hydrology_23 Nov\VOLUME III - Technical Annex\Appendix D - Design Calculations\2.Orifice self sheet Q=11.08_November 22, 2010.xlsx
. m sec
2 Calculation
2.1 During Normal Flow Condition
Gravel Flushing Discharge (QSF) = 1.108 m3/sec
Sediment Flushing discharge (Qb) = 1.108 m3/sec
Total discharge (Qdesign) = 13.30 m3/sec
Net area of orifice required 22.16 m2
Gross horizontal opening 7.25 m
No of bar in each bay 8 NosNet horizontal opening provided 6.51 m
Net vertical height of orifice required (H)= 3.40 m
Net area provided 22.79 m2
Top level of orifice opening 1380.00 m
Check the discharge in headrace canal by the formula below;
h = (Q/AC)2/2g
h 0.05 m
hh(normal) 1381.45 m
Q = A.C. (2g (hr-hh))= 13.67 m3/s
V = Q/A 0.60 m/s
2.2 During Flood Flow Condition
The radial gate will be open accordingly to pass the high flood
h
3 Output
No of orifice = 3 Nos
Orifice Height (H) = 3.50 m
Each Orifice Width (W) = 2.25 m
Clear vertical spacing of bar to bar = 0.25 m
Thickness of central pier = 0.50 m
TRUEOrifice size is ok
Velocity Ok
OK
I:\ED\Jobs\OPEN\751220 Nyadi Implementation\03Reports\Final Review 30 MW as per Damodar Hydrology_23 Nov\VOLUME III - Technical Annex\Appendix D - Design Calculations\2.Orifice self sheet Q=11.08_November 22, 2010.xlsx
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Nyadi Hydropower Project
Hydraulic Design Review of Settling Basin
Note: Size review (Ref. Feasibility Study Report March 20 00)
Design flow (QT) 11.08 m3/sec
Flushing discharge (Qflush) 1.108 m3/sec (10% of design flow)
Total discharge in basin (Qbasin) = 12.188 m3/sec
No of basin 1 nos first trial
Discharge in one basin (Q1basin) = 12.188 m3/sec
Criteria: > 90% settling of 0.2 mm
Fall velocity (w) 0.02 m/sec 1.5 cm/s ec For 0.2 mm partic le and 150C temperature
Water temperature 150C
Assume inlet transition 1:5 expansions, which gives t he performance parameter m = 1/5 (very good performance)Use Vetter's equation and Hazen's method to calculate Set tling basin surface area:
h = 1 - e- (w*A/Q)
1-h = (1+m w Ap/Q)(-1/m)
0.125
A, m2 h A, m2 h
Vetters equation
2200 0.973 2500 0.964
2190 0.973 2480 0.963
2180 0.972 2460 0.962 Hazen's equation
2170 0.972 2440 0.961
2160 0.971 2420 0.960
2150 0.971 2400 0.959
2140 0.970 2380 0.958
2130 0.970 2360 0.958
2120 0.969 2340 0.957
2110 0.969 2320 0.956
2100 0.968 2300 0.955
2090 0.968 2280 0.954
2080 0.967 2260 0.953
2070 0.967 2240 0.951
2060 0.966 2220 0.950
2050 0.965 2200 0.949
2040 0.965 2180 0.948
2030 0.964 2160 0.947
2020 0.964 2140 0.946
2010 0.963 2120 0.944
=
=
1 e
wA
Q
s
( )( )mQmwA /1/11 +=
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2000 0.962 2100 0.943
1990 0.962 2080 0.942
1980 0.961 2060 0.940
1970 0.961 2040 0.939
1960 0.960 2020 0.938
1950 0.959 2000 0.936
1940 0.959 1980 0.935
1930 0.958 1960 0.933
1920 0.957 1940 0.931
1910 0.956 1920 0.930
1900 0.956 1900 0.928
1890 0.955 1880 0.926
1880 0.954 1860 0.925
1870 0.954 1840 0.923
1860 0.953 1820 0.921
1850 0.952 1800 0.919
1840 0.951 1780 0.917
1830 0.950 1760 0.915
1820 0.950 1740 0.913
1810 0.949 1720 0.911
1800 0.948 1700 0.909
1790 0.947 1680 0.906
1780 0.946 1660 0.904
1770 0.945 1640 0.902
1760 0.944 1620 0.899
1750 0.943 1600 0.897
1740 0.942 1580 0.894
1730 0.942 1560 0.891
1720 0.941 1540 0.889
1710 0.940 1520 0.886
1700 0.939 93.856% 1500 0.883
1690 0.938 1480 0.880
1680 0.937 1460 0.877
1670 0.935 1440 0.874
1660 0.934 1420 0.871
1650 0.933 1400 0.867
1640 0.932 1380 0.864
1630 0.931 1360 0.860
1620 0.930 1340 0.857
1610 0.929 1320 0.853
1600 0.928 1300 0.849
1590 0.926 1280 0.845
1580 0.925 1260 0.841 A used 1700
1570 0.924 1240 0.837
1560 0.923 1220 0.832
1550 0.921 1200 0.828
1540 0.920 1180 0.823
( )( )mQmwA /1/11 +=
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1530 0.919 1160 0.819
1520 0.917 1140 0.814
1510 0.916 1120 0.809
1500 0.915 1100 0.804
1490 0.913 1080 0.798
1480 0.912 1060 0.793
1470 0.910 1040 0.787
1460 0.909 1020 0.781
1450 0.907 1000 0.775
1440 0.906 980 0.769
1430 0.904 960 0.763
1420 0.903 940 0.756
1410 0.901 920 0.749
1400 0.899 900 0.742
1390 0.898 880 0.735
1380 0.896 860 0.727
1370 0.894 840 0.720
1360 0.893 820 0.712
Calculate basin width based on Vetter's method:
No of chambers 1 2 3 8.8542
Flow per chamber, m3/sec 12.188 6.094 4.063 13.281
Assumed width, m 8.000 8.000 8.000 13.28 Width and Length ratio OK
Required length for 1700 m2 =assumed (area/ width) 212.50 106.25 70.83
Minimum depth = Q/BV 7.74 3.87 2.58
Maximum flow velocity V = 0.44*SQRT(dlimit) (ref. Civil works guidelines for micro- hydropower in Nepal, page # 73)
Where, dlimit = 0.15 mm
V = 0.20 m/s
Adopt two basins width of Adopt
25 25.00
39.5
Sediment storage in two chambers:S = Q*T*C
S - sediment load in kg stored in the basin
Q - Discharge in m3/sec
T - sediment emptying frequency in seconds 28800 (8 hrs)
C - sediment concentration of the incoming flow in kg/m3, assume 10,000 ppm 10 kg
Sediment density 2600 Kg/m3
Packing factor of density 0.5
Sediment load (S) = 3510144 Kg
Required inlet transition length@1:9 (For
Horizontal transition)
m (transition from 3 m wide canal to 16
m wide settling basin)
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o ume o se iment . m
Required depth 3.08 m
Total required depth 6.952 m. 7.00 Adopted
Water level at settling basin 1377.50 m
Bottom level of Beginning of parallel section 1370.50 m
Available head for flushing 6.625 m
Checking for flushing of deposition in settling basin
h, b, m, a, p, R, n, s, v, Q,
particle
size, based
on Shield's
simplied
formula
particle
size, based
on ACI
committee
report
m m h:m m2
m m m/s m3/s mm mm
0.40 0.50 1.00 0.20 1.30 0.15 0.015 0.02 2.71 0.54 33.85 305.00
0.43 0.50 1.00 0.22 1.36 0.16 0.015 0.02 2.76 0.59 34.78 316.26
0.45 0.50 1.00 0.23 1.40 0.16 0.015 0.02 2.79 0.63 35.36 323.29
0.50 0.50 1.00 0.25 1.50 0.17 0.015 0.02 2.86 0.71 36.67 339.35
The present table shows that at any height the deposited sediments will be flushed out.
Flushing time calculation for intermittent flushing of single chamber
Sediment volume in settling basin 1350.1 m3 Total volume of sediment/No. of chambers
Design inflow to settling basin 6.09 m3/sec Total basin discharge/No. of chambers
Inflow to settling basin during flushing 4.88 m3/sec 80% of design flow of each chamber of settling basinus n g sc a rge w en
the gate is opened fully) 1.67 m3/sec b*h*0.65*sqrt(2*g*H)
Assuming that the settling basin will not be empitied, only deposition will be flushed out
Vt= V in + Qin*t-Qflush* t Accumulated volume in t ime t = previously stored volume+discharge vol in
t time-outgoing volume due to flushing in t time
t = -7.0 Min
Drain time 13.5 Min
Recharge time 3.7 Min
Total time required 10.2 Min
Adopted size of settling basin Adopted
Inlet transition length = 25.00 m. 25.00 m.
Width of chamber = 8.00 m 8.00 m
Settling basin efficency = 93% 93.00%
Nos. of chamber = 2 nos. 2.00 nos.
Length of parallel section = 106.00 m 128.00 m
Water depth in parallel section = 3.90 m 4.50 m
Required storage depth = 3.08 m 3.75 m
Total depth of settling basin including f reeboard = 7.98 m 10.30 m
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CALCULATION FORM
Date: Calc. by Basanta Bagale
Job: Nyadi HP Job no. 751220 Chkd.
Input Datas Drg. No.
Project Life Period= 30 years
Design Discharge(Q)= 12.19 m3/s =1.1 times Design discharge
Tunnel Intake Level= 1381.50 m
Tail Race Water Level= 1032.00 m
Gross Head= 347 m
Length of headrace Tunnel (L)= 3955.00 m
Section Type of Head Race tunnel =>
Diameter of Tunnel= 3.20
X-section area of Head Race Tunnel (f) = 9.141 m2
Wetterd Perimeter of Tunnel (Pt)= 11.427 m
Hydraulic Radius of Tunnel (Rt)= 0.8 m
Area of Surge Tank(F)= 19.635 m2
Tunnel lining Material= Concrete
Manning's Coefficient for Concrete lines Tunnel(n)= 0.015
Coefficient of Roughness for tunnel(K)= 66.667
Ressistance Factor ()= 1.318059579
Damping Factor(m)= 0.014044698
Diameter of penstock (dp)= 1.75 m
Area of X-section of Penstock(Ap)= 2.405 m2
Diameter of pipe after tri-forcation(dtp)= 1 m
Orifice Head loss Coefficient(d)= 1.843
Is calculated from
Manning's
Strickler Formula
= 1.1*L/(K^2)/(R^(4/3))
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Hydro Consult
CALCULATION FORM Date: Calc. by Basanta Bagale
Job no. 751220 Chkd.
Job: Nyadi HP Drg. No.
Objective: Calculation for the submergence in the surge tank
hs > 1.5*Vp^2/2/g
where,
hs= Submergence Head
Vp= Velocity in Penstock
g= acceleration due to gravity
Vp =Q/Ap
Where,
At= X-section area of Tunnel
Q= Discharge through Tunnel 12.19 m3/sec
dt= diameter of Tunnel 3.2 m
At= 9.141 m2
Vt= 1.333 m/s
Gordon (1970)
S= submegence (ft.)
k= coefficient 0.3 for symmetrical approach 0.30
0.4 for unsymmetrical approach 0.40
1.73 m
Prosser (1977)
4.80 m
ITDG Manual
0.14 m
4.800 mConsidered submergence (S)
Submergence (S)
Submergence (S)
Submergence (S)
dkvS=
dS 5.1=
g
vS
25.1
2
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Hydro Consult
CALCULATION FORM
Date: Calc. by Basant Bagale
Job: Nyadi HP Job no. 751220 Chkd.
Summary Drg. No.
Surge Calculated from Finite Difference Method
Surge Level Max. Surge Surge Level(m) Max. Surge(m)
1367.665 12.485
1390.288 9.012 1376.604 4.672
1390.288 9.012 1367.665 12.485
5 m
Free Board for Surge Tank= 1.712 m
4.8 m
So,
21.497
Now,
1381.5 masl
1390.288 masl 22.623
1367.665 masl
1392.000 masl 1392 1.712
1360.265 masl
Thickness of Surge Shafts
Elevation form Elevation to Height(m) Thickness(m)
Estimated
Reinforcement
(t)
Volume ofconcrete
Wt. of Concrete
1362.224 1363.224 1.000 5 0.398879524 orifice
1363.224 1370.046 6.822 0.9 2.285 877.8524706 219.4631176
1370.046 1376.868 6.822 0.7 1.656 823.843969 205.9609922
1376.868 1383.690 6.822 0.5 1.065 771.550023 192.8875057
1383.690 1390.512 6.822 0.3 0.513 720.9706326 180.2426581
3194.217095 798.5542738
Level of Center of Head Race Tunnel=
Static Water level=
Water level of Highest Upsurge=
Level of Lowest Downsurge=
Absolute Maximum Surge=
Diameter of surge tank=
Submergence head=
Total surge in Surge Shaft=
Upsurge
Level of the top of ST=
Downsurge
Open all Valves from closed stage=
Closing All Valves at once=
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Nyadi Penstock Alignment Bend details surface plus vertical shaft
Easting Northing
X Y
10.00 PS 0.00 0.5 0 541632.30 3134827.46 0.00 0.00 0.00 1393.95 1355.50 0 .00 -3
2 17.45 TP 0.00 0.83 -0.01 541632.97 3134810.02 17.45 17.45 17.45 1380.24 1355.25 0.25 -2
339.71 VB1 0.00 0.83 5.31 541633.82 3134787.78 22.26 22.26 39.71 1362.72 1354.93 0 .32 -7
4 93.62 VB2 0.00 6.14 10.83 541635.89 3134733.91 53.91 54.22 93.93 1349.74 1349.125 5 .80 -05156.02 CB3 11.24 16.97 18.31 541638.28 3134671.55 62.40 65.24 159.18 1331.08 1330.080 19.04 -
6 213.07 VB4 0.00 35.28 -12.99 541629.31 3134615.21 57.05 69.89 229.07 1290.71 1289.710 40.37 -
7273.07 VB5 0.00 22.29 -0.93 541619.88 3134555.95 60.00 64.85 293.92 1265.11 1265.111 24.60 0
8 333.075 CB6 1.62 21.36 -6.61 541610.45 3134496.70 60.00 64.43 358.34 1241.64 1241.643 23.47 0
9393.066 VB7 0.00 12.83 -12.83 541602.02 3134437.30 59.99 61.53 419.87 1227.98 1227.980 13.66 0
10 440.616 VB8 0.00 14.75 -14.75 541595.33 3134390.23 47.55 55.35 475.22 1213.76 1213.320 14.66 -0
475.22 m
Bend angle Bend angle Pipe Summary:
C lockwise (downturn bend) +ve Anticlockwise(upturn) -ve
underground 1750
ID Pipe L 200.16m
1450 ID
Pipe L
1750 ID Pipe L
675.38m
1000 ID
Pipe L 4
tock Start, TP = Tunnel Portal, VB= Vertical Bend, CB= Combined bend
Transition
(1.75-
1.45)
Anc to anch.
hor distance,
m (from
coordinates)
Anc to anch incl
Length at pipe
bottom (Leff), m
Cumulative
Length
of pipe, m
Ground
Level , masl
Gro
inv
he
Invert
Level, m
Invert
level diff,
m
S.
No.
Chainage,
m
Anchor
Identific-
ation/SOP
Hor.
defln
Angle
'Degree'
Verical
Angle with
horizontal
a 'Degree'
Ver. delection
angle degree
5.Penstock Calculation_350MPA_Q=11.08_November 22 2010.xls
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Nyadi Penstock Calculation
Weir Elevation 1381.5 m
Turbine Level 1034.5 m Effective Thickness =
Design flow Qd 11.08 m3/s
Static head Hg 347.00 m
Length of penstock pipe Lp 675.38 m
Youngs' modulus of steel E 200,000 N/mm2
Yield Stress of steel S 350 N/mm2 40mm THK
Steel Specification SAILMA 350
Required Safety Factor SF 2.5
Steel Density 7850 kg/m3
Water Density 1000 kg/m3
Welding efficiency 0.9
1 USD 71.25 Rs
Rate of Steel 170.5 Rs/kg
Surge Head = 0.15 x Static Head
Rate of Steel 2.39 USD/kg Water Hammer =10 ~15 % of static head (Refer:E. mosonyi, Pg 715 (old))
Nos of turbine units 3
Number of nozzle in each turbine units 2
Surge Head 15% Static Head
NOTE: Penstock permissible veloci ty for properly settled water with respect to abrassion, v = 3 to 5 m/se
(Refer: Mosonyi High Head Power Plants Volume Two/A page 330
Segment #1
Static head 51.42 m Elevation 1330.08 m
Length of penstock 159.22 m
Diameter, d, mm 1250 1350 1450 1550 1650 1750 1850 1950
Penstock flow velocity,V m/s 9.03 7.74 6.71 5.87 5.18 4.61 4.12 3.71
Handling Thickness, mm 4.40 4.65 4.90 5.15 5.40 5.65 5.90 6.15
Gross thickness, mm 8 8 8 8 8 8 8 8
Effective thickness, teff mm 4.88 5.11 5.34 5.57 5.80 6.03 6.26 6.49
Internal Pressure, N/Mm^2 0.58 0.58 0.58 0.58 0.58 0.58 0.58 0.58
Sur e Head, Hs m 7.71 7.71 7.71 7.71 7.71 7.71 7.71 7.71
( ) 2)**2/(** += wyw FOSdPit
2*
*4
d
QdV
=
Tw HgPi **=
Page 2of 3
, . . . . . . . .
Total Head, Htot m 59.13 59.13 59.13 59.13 59.13 59.13 59.13 59.13
Factor of safety 4.10 3.92 3.75 3.59 3.45 3.32 3.20 3.08
Check OK OK OK OK OK OK OK OK
Weight of steel, ton 41 45 48 51 55 58 61 65
Segment #2
Static head 105.00 m Elevation 1274.20 m
Length of penstock 124.02 m
Diameter, d, mm 1250 1350 1450 1550 1650 1750 1850 1950
Penstock flow velocity,V m/s 9.03 7.74 6.71 5.87 5.18 4.61 4.12 3.71Gross thickness, mm 8 10 10 10 10 12 12 12
Effective thickness, teff mm 7.88 8.35 8.82 9.29 9.76 10.23 10.70 11.17
Internal Pressure, N/Mm^2 1.18 1.18 1.18 1.18 1.18 1.18 1.18 1.18
Surge Head, Hs m 15.75 15.75 15.75 15.75 15.75 15.75 15.75 15.75
Total Head, Htot m 120.75 120.75 120.75 120.75 120.75 120.75 120.75 120.75
Factor of safety 2.54 3.00 2.84 2.69 2.56 2.93 2.80 2.69
Check OK OK OK OK OK OK OK OK
Weight of steel, ton 32 44 47 50 53 68 72 76
Segment #3
Static head 157.00 m Elevation 1222.20 m
Length of penstock 176.63 m
Diameter, d, mm 1250 1350 1450 1550 1650 1750 1850 1950
Penstock flow velocity,V m/s 9.03 7.74 6.71 5.87 5.18 4.61 4.12 3.71
Gross thickness, mm 12 12 14 14 14 16 16 16
Effective thickness, teff mm 10.79 11.49 12.19 12.89 13.60 14.30 15.00 15.71
Internal Pressure, N/Mm^2 1.77 1.77 1.77 1.77 1.77 1.77 1.77 1.77
Surge Head, Hs m 23.55 23.55 23.55 23.55 23.55 23.55 23.55 23.55
Total Head, Htot m 180.55 180.55 180.55 180.55 180.55 180.55 180.55 180.55
Factor of safety 2.78 2.61 2.87 2.71 2.57 2.80 2.67 2.55
Check OK OK OK OK OK OK OK OK
Weight of steel, ton 69 75 94 100 107 129 137 144
Segment #4
Static head 232.75 m Elevation 1156.20
Length of penstock 75.75 m
Diameter, d, mm 1250 1350 1450 1550 1650 1750 1850 1950
Penstock flow velocity,V m/s 9.03 7.74 6.71 5.87 5.18 4.61 4.12 3.71
Gross thickness, mm 16 18 18 20 20 22 22 25
( ) 2)**2/(** += wyw FOSdPit
2*
*4
d
QdV
=
Tw HgPi **=
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Effective thickness, teff mm 15.02 16.07 17.11 18.15 19.19 20.23 21.28 22.32
Internal Pressure, N/Mm^2 2.63 2.63 2.63 2.63 2.63 2.63 2.63 2.63
Surge Head, Hs m 34.91 34.91 34.91 34.91 34.91 34.91 34.91 34.91
Total Head, Htot m 267.66 267.66 267.66 267.66 267.66 267.66 267.66 267.66
Factor of safety 2.66 2.80 2.63 2.75 2.61 2.72 2.59 2.80
Check OK OK OK OK OK OK OK OK
Weight of steel, ton 40 48 52 62 66 76 81 97
Segment #5
Static head 267.75 m Elevation 1121.20Length of penstock 35.00 m
Diameter, d, mm 1250 1350 1450 1550 1650 1750 1850 1950
Penstock flow velocity,V m/s 9.03 7.74 6.71 5.87 5.18 4.61 4.12 3.71
Gross thickness, mm 18 20 20 22 22 25 25 28
Effective thickness, teff mm 16.98 18.18 19.38 20.58 21.78 22.98 24.18 25.37
Internal Pressure, N/Mm^2 3.02 3.02 3.02 3.02 3.02 3.02 3.02 3.02
Surge Head, Hs m 40.16 40.16 40.16 40.16 40.16 40.16 40.16 40.16
Total Head, Htot m 307.91 307.91 307.91 307.91 307.91 307.91 307.91 307.91
Factor of safety 2.65 2.75 2.58 2.67 2.53 2.72 2.59 2.76
Check OK OK OK OK OK OK OK OK
Weight of steel, ton 21 25 27 31 33 40 42 50
Segment #6
Static head 302.75 m Elevation 1086.20
Length of penstock 35.00 m
Diameter, d, mm 1250 1350 1450 1550 1650 1750 1850 1950
Penstock flow velocity,V m/s 9.03 7.74 6.71 5.87 5.18 4.61 4.12 3.71
Gross thickness, mm 20 22 22 25 25 28 28 30Effective thickness, teff mm 18.94 20.30 21.65 23.01 24.36 25.72 27.07 28.43
Internal Pressure, N/Mm^2 3.42 3.42 3.42 3.42 3.42 3.42 3.42 3.42
Surge Head, Hs m 45.41 45.41 45.41 45.41 45.41 45.41 45.41 45.41
Total Head, Htot m 348.16 348.16 348.16 348.16 348.16 348.16 348.16 348.16
Factor of safety 2.64 2.71 2.54 2.72 2.57 2.72 2.59 2.64
Check OK OK OK OK OK OK OK OK
Weight of steel, ton 23 27 29 36 38 45 48 54
Page 3of 3
Segment #7
Static head 351.45 m Elevation 1030.05
Length of penstock 69.76 m
Diameter, d, mm 1250 1350 1450 1550 1650 1750 1850 1950
Penstock flow velocity,V m/s 9.03 7.74 6.71 5.87 5.18 4.61 4.12 3.71
Internal Pressure, N/Mm^2 3.96 3.96 3.96 3.96 3.96 3.96 3.96 3.96
Gross thickness, mm 22 25 25 28 28 30 32 36
Effective thickness, teff mm 21.67 23.24 24.81 26.39 27.96 29.53 31.11 32.68
Surge Head, Hs m 52.72 52.72 52.72 52.72 52.72 52.72 52.72 52.72
Total Head, Htot m 404.17 404.17 404.17 404.17 404.17 404.17 404.17 404.17
Factor of safety 2.54 2.69 2.52 2.65 2.50 2.54 2.57 2.75
Check OK OK OK OK OK OK OK OK
Weight of steel, ton 51 62 67 80 85 96 109 129
weight of steel 277 326 363 410 436 513 549 614
weight of steel with Wastage (5%) 305 369 402 455 503 539 640 722
Cost of steel, USD 730218 882081 961225 1089938 1203093 1289963 1530931 1727929
Selected Diameter = 1750 mm
Section Segment#1 Segment#2 Segment#3 Segment#4 Segment#5 Segment#6 Segment#7
Length of penstock of section, m 159.22 124.02 176.63 75.75 35.00 35.00 69.76
Static Head, m 51.4 105.0 157.0 232.8 267.8 302.75 351.45
Surge Head, m 7.7 15.8 23.6 34.9 40.2 45.4 52.72
Total Head, m 59.13 120.75 180.55 267.66 307.91 348.16 404.17
Pipe Thickness. mm 8 12 16 22 25 28 30
Pipe weight. Ton 58 68 129 76 40 45 96
Penstock pipe 539 Ton
Expansion Joints 16 Ton
Stifners, saddle, wear plate 15 Ton
Weight of 1.45 m dia pipe 5.10 Ton
Weight of 1 m dia pipe 8.74 Ton
Total weight of Steel 584 Ton
Total Cost of steel, USD 1,397,277.11
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ob Nyadi Hydropower Project (NHP)
Subject Anchor Block Design Calculated By:
Date Checked By:
ANCHOR BLOCK- CB3
Chainage: 0+156.02
Length of Penstock 675.38 m
Weir Level 1381.50 masl
Anchor Block Level 1330.08 masl
Ground Level 1331.08 masl
Young's Modulus ,E E 200000 N/mm2
Design Discharge, Q Q 11.08 m3/sec
Nominal wall thicknesss, t t 16.00 mm
Pipe internal diameter,d d 1750 mm
Pressure wave velocity, a a 976.236 m/s
Velocity in Penstock, v v 4.61 m/s
Critical time, Tc Tc 1.38 sec
Closure time, T T 6 sec
Nos of turbine units 3
Number of nozzle in each turbine units 2
Angle of internal friction f 30o
Unitweight of concrete gconcrete 24.00 kN/m3
Hydro Consult
CALCULATION SHEET
Page 1of 2
Unitweight of steel gsteel 78.50 kN/m3
Unitweight of soilg
soil 18.00kN/m
3
for boulder mixed soilFriction coeff f 0.25 for steel to rusty plates movement, ITDG, Pg 7-9
Coefficien of friction of soli m 0.50 RESULTS:
Allowable bearing capacity 160.00 kN/m2
Expansion Contraction
Safe When Check against overturning Safe When Check against overturning
Deflection angle in horz bend D 11.241 Safe When Check on bearing capacity Safe When Check on bearing capacity
Deflection angle in vert bend u/s a 16.97 Sa fe When Check against s lid ing Sa fe When Check against s lid ing
Deflection angle in vert bend d/s b 35.28
1/2 the distance betn u/s pier to anchor block L1u 4.00 m
1/2 the distancebetn d/s pier to anchor block L1d 4.00 m
Distance between two consecutive support
piers L2u 8.00 m
Distance to upstream expansion joint L4u 65.89 m
Distance to d/s expansion joint L4d 5.65 m As exp joints is just 2.0m d/s from anchor block face
Distance between consecutive anchor blocks 65.24 m
Penstock clear cover by anchor at uphill face 1.00 m 0.010Asume width of block B 6.00 m Base width 7.50
Length of block L 7.30 m Base thickness 1.00
Assume height of block at upstream end hu 6.00 m
Number of support pier 9.00 14.6 4.866667 29.2 48.6666667
Assume height of block at downstream end hd 4.00 m 0.4 4.055556 4.866667
Assume depth o f burried at upstream h1 2.00 m
Increase the downstream depth by factor 0.00 Projection Depth = 0
Buried depth of block at d/s face h2 1.000
0
1
2
3
4
5
6
7
-1.00 1.00 3.00 5.00 7.00
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Tunnel intake Level 1381.50 m Turbine axis level 1034.00 m
Generator Effeciency 97.00% Turbine Efficiency 89.00%
Transfermer efficiency 99.00%
Gross head, m 347.50 m Overall efficiency 85.47%
Dry season outage 4% Wet season outage 4%
Synchronous Speed N 473 rpm Frequency f 50 Hz
Turbine units n 3 No Number of nozzle nj 2 No
Length of tunnel 3950.00 m Length of penstock 650 m
Manning's coefficient 0.014 For concrete Friction coeficient 0.0200 For shotcrete
Tunnel Diameter 3.20 m Penstock Diameter 1.750 m
Height to the stringer 1.60 m
NYADI HYDROELECTRIC PROJECT
TURBINE DESIGN CALCULATION
Sectional Area of tunnel 9.14 m Tunnel Perimeter 11.427 m
Probability excedence, % 40.00%
Design flow, m3/s 11.08 m
3/s D/s release m
3/s 0.308 m
3/s
Rated power Calculation
Gross head Hg 347.500 m Gross head = Turbine axis level - Tunnel intake level
Net head H 339.370 m Net Head = Gross head - Total head loss
Net power in kW P 30000.00 kW Net power = Unit wt. of water x Overall efficiency x Design discharge x Net head
Net power in MW PMW 30.00 MW In MW Net power = 30000/1000
Net power in horse power Php 40215 Hp In Horse power Net power = 30000/0.746
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NYADI HYDROELECTRIC PROJECT
TURBINE DESIGN CALCULATION
Synchronous SpeedSpecific Speed for single Jet (assume) 20.00 Ref: High head power plants E. Mosonyi Vol 2/B; Pg 859, eqn 28/101
jet diameter dj 0.172 m Ref: High head power plants E. Mosonyi Vol 2/B; Pg 854, eqn 6/101
pitch circle diameter D 1.862 m Ref: High head power plants E. Mosonyi Vol 2/B; Pg 856, eqn 16/101
Synchronous Speed Ns 397 rpm Ref: High head power plants E. Mosonyi Vol 2/B; Pg 856, eqn 16/101
Synchronous Speed for multiple jets Ns 561 rpm
no of pole pair 5.35 Ref: Water Power Engineering M.M Dandekar; Pg 310, eqn 13.3
Take no of pole pair P 6 Pairs
Calculated Synchronous Speed N 473 rpm Ref: Water Power Engineering M.M Dandekar; Pg 310, eqn 13.3
Calculated Specific Speed (of runner with 2 jet)Ns
37.6Ref: Water Power Engineering M.M Dandekar; Pg 310, eqn 13.4
Dischar e in each unit, Q /n Q 3 693 m3/s Dischar e er unit = 11.08/3 . .
The actual velocity of jet at nozzle is given by
Ref: High head power plants E. Mosonyi Vol 2/B; Pg 854, eqn 2/101
Vj 79.151 m/s Nozzle Velocity = KvXSQRT(2X9.81Xnet head)
Where Kv Varies from 0.96 to 0.99 Kv 0.97
The speed ratio Kuvaries frpom 0.43 to 0.47 Ku 0.44 Ref: Hydraulics and Fluid Mechanics P.N. Modi & S. M. Seth; Pg 1017
Bucket velocity = KuVj u 34.827 m/s Bucket velocity = 0.44X79.151 m/s
Mean Diameter of the Pelton Wheel (pitch diameter) is
Ref: Hydraulics and Fluid Mechanics P.N. Modi & S. M. Seth; Pg 1017
D 1.406 m Pitch Diameter = (60X34.827)/(3.142X)
Adopt D 1.500 m
Calculation of Nozzle Diameter Method 1
Nozzle Discharge Qt/nj Qj 1.847 m3/s Discharge per unit = 3.694/2 m3/s
Diameter of Nozzle, D/m 0.172 m Nozzle Diameter = SQRT(1.84666666666667X4)/(3.142X79.151)
Adopt Nozzle, diameter d 0.180 m This should be equal to or greater than calculated nozzle diameter
Here, actual specific speed for single jet 26.040 rpm Ref: High head power plants E. Mosonyi Vol 2/B; Pg 856, eqn 16/101
Nozzle Area a 0.0254 m2
Nozzle area =3.142X(0.18X0.18)/4 m2
Calculated jet ratio m 8.33 Calculated jet ratio = 1.5/0.18
Number of buckets Z 20 No Number of buckets = 0.5X8.33333333333333+15
gHKVvj
2=
N
uD
60=
4
1
90
H
Ns
=
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NYADI HYDROELECTRIC PROJECT
TURBINE DESIGN CALCULATION
Calculation of Nozzle Diameter Method 2
Total Area of nozzle required for the discharge in unit a 0.047 m2
Total nozzle area = 3.693/79.151 m2
Adopt jet ratio m 11 Varies from 11 to 14
Diameter of Nozzle, D/m d 0.136 m Nozzle Diameter = 1.5/11 m
Adopt Nozzle, diameter d 0.140 m
Nozzle Area a 0.0146 m2
Nozzle area =3.142X(0.14X0.14)/4 m2
Number of nozzle nj 3.195 No Required number of nozzle = 0.047/0.015
Number of nozzle (adopt) nj 3 No
Calculated jet ratio m 11 Calculated jet ratio = 1.5/0.14
Number of buckets Z 20 No Number of buckets = 0.5X10.714+15
Nozzle Discharge Qt/nj Qj 1.231 m3/s Discharge per unit = 3.694/3 m3/s
Bucket Dimensions in meter
Parameters Method 1 Method 2
Low High Low High
B = (4 to 5)dj Width 0.720 0.900 0.720 0.900
L = (2.4 to 3.2)dj Length 0.432 0.576 0.432 0.576
C = (0.81 to 1.05)dj Depth 0.146 0.189 0.146 0.189
l = (1.2 to 1.9)dj 0.216 0.342 0.216 0.342
M= (1.1 to 1.25)dj 0.198 0.225 0.198 0.225
Setting Parameters
Outer Diameter of the bucket, Do D+L 1.932 2.076 1.932 2.076 2.004
Housing diameter (0.78+2.06Do) 4.760 5.057 4.760 5.057
Setting height (0.5 to 1 +Do-B/2) hs 2.072 2.626 2.072 2.626
Free height (hs-B/2) hf 1.712 2.176 1.712 2.176
Maximum water depth 1+Do 2.932 3.076 2.932 3.076
Ref: High head power plants E. Mosonyi Vol 2/B; Pg 971
Turbine Axis level from Maximum TWL h sp hf+Do/2 2.678 3.21 2.678 3.214
Ref: High head power plants E. Mosonyi Vol 2/B; Pg 878
width of the tailwater flume, Bt 1.5+.75Do 2.949 3.057 2.949 3.057
Ref: High head power plants E. Mosonyi Vol 2/B; Pg 969
Maximum Tailwater Level, MTWL 1030.200 m
Minimum Turbine Axis Level required hsp+MTWL 1033.414 m Turbine Axis = 1030.2+3.214
Turbine axis level provided 1034.000 m
Turbine Axis level from max TWL, h sp provided 3.800
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Hydro Consult Nyadi Hydropower Project
Subject: Tailrace tunnel
Data
Q design 11.08 m3/sec
Q in each tunnel 11.08 m3/sec
Let assume size B 3.60 m
Height of tunnel H 3.60 H-B/2
water depth D 1.90 m 1.80
slope sn 0.0013 750
n 0.020
Height of water at tunnel top dome (D-(H-B/2)) 0.10 m
Angle subtended 0.0556 radian
Calculation for D(H-B/2)Wetted Area 6.84
Wetted Perimeter 7.40
Hydraulic Radius 0.92
Velocity limit 1.75
Nyadi Hydropower Project (NHP)
velocity normal
Discharge 11.85 m3/sec OK
Velocity 1.73 m/sec OkShield dn = 11RS 0.01 mm
Summary
Breadth, B 3.60 m
Design Discharge Depth, H 1.90 m
D shape tunnel top curve depth 1.8 m
Total Height of Tunnel 3.60 m
Slope 1:750
2
1
3
2
1SR
nv =
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Hydro Consult Nyadi Hydropower Project
Subject: Tailrace canal below turbine
Data
Q design 11.08 m3/sec
Q in each canal 3.693 m3/sec
Assume size B 2.00 m
Height of tunnel H 2.00
water depth D 1.30 m
slope sn 0.001 1000
n 0.014
Height of water at tunnel top dome 0.30 m
Angle subtended 0.304692654 radian
Calculation for D(H-B/2)
Area 2.59
Perimeter 4.61Hydraulic Radius 0.56
Velocity limit 3
Nyadi Hydropower Project (NHP)
12
1
Discharge 3.99 m3/sec OK
Velocity 1.54 m/sec Ok
Shield dn = 11RS 0.01 mm
Summary
Breadth, B 2.00 m
Design Discharge Depth, H 1.30 m
D shape tunnel top curve depth 1 m
Total Height of Tunnel 2.00 m
Slope 1:1000
nv =
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Hydro Consult Nyadi Hydropower Project
x ng t e eve o power ouse an ta race
Q design 11.08 m3/sec
1000 year flood level at Tailrace exit 1027.00 m
Invert level of Tailrace tunnel outlet 1028.00 m
Length of Main Tailrace 356.50 m
Slope of Tailrace (1 in) 750.00 m
Invert Level at 3.6m width Tailrace Start 1028.48 m
Design discharge Tailrace water depth 1.90 m
Tailwater level 1030.38 m
Calculated Height from turbine axis to tailrace WL 3.67 m
Turbine axis level calculated 1034.05 m
Adopt Turbine Axis level 1034.00 m
Adopted Height from turbine axis to tailrace WL 3.62 m
Provided floor level of PH 1032.50 m
Design discharge Tailrace water depth below turbine 1.30
Invert Level below Turbine 1029.08 m
Nyadi Hydropower Project (NHP)
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Hydro Consult
Headloss Calculation
Nyadi Hydropower Project
January 6, 2011
Sn Description Reference Symbol Unit Value
Turbine Discharge Qt m3/sec 11.080
Orifice Discharge Qo m3/sec 15.512
Normal water level at weir crest m 1381.500
Turbine Axis level m 1034.000
Normal Tail water level m 1030.830
1 Orifice
Width of the Orifice Wo m 7.500
Height of the Orifice Ho m 3.000
2 Coarse Trashrack
Trashrack coefficient Ktr 2.420
thickness of the bar t m 0.010
clear spacing between the bars b m 0.150
angle with horizontal, a ao
30.000
5 Gravel trap Length Lg m 3.000
Width Wg m 3.000
Height hg m 1.000
Bend
angle of bend q degree 0.000
radius of bend rc m 100.000
4 Fine Trashrack
thickness of the bar t m 0.010
clear spacing between the bars b m 0.050
angle with horizontal, a ao
72.000
trashrack coefficient Ktr 2.420
6 Approach tunnel Length Lac m 55.500
Width/ dia Wac m 3.000
tunnel height hac m 3.000
Slope S 1 in 500 0.0020
6 SB Bifurcation
Length Lac m 60.000
Width/ dia Wac m 3.000
tunnel height hac m 3.000
Slope S 1 in 100 0.0100
7 Settling basin
No of bay 2
Length Lsb m 128.000 Inlet transition length Ltr m 25.000
Cross section area m2 31.000
Perimeter m 22.500
Average width Wtr m 8.000
Average depth htr m 10.000
8 Tunnel Intake
Intake (Bellmouth)
Diameter d m 3.200
9 Tunnel
Length Lt m 3937.000
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Hydro Consult
Headloss Calculation
Nyadi Hydropower Project
January 6, 2011
Sn Description Reference Symbol Unit Value
Diameter Dt m 3.200
Total height Ht m 3.200
Concrete lined length Lcon m 1200.000
Slope St 1 in 500 0.0020
Bend 1
radius r 10.000
equivalent circular diameter d 3.100
Bend angle in degrees angle 22.000
Bend 2
radius r 10.000
equivalent circular diameter d 3.000
Bend angle in degrees angle 38.000
10 Penstock
Length Lp m 675.380
Diameter Dp m 1.750
11 Branching and Valve Losses
Length of the branching (Total) Lbr 42.500
Diameter 1 Dp1 1.750
Diameter 2 Dp2 1.550
Diameter 3 Dp3 1.100
Branch bend angle degree 60.000
surface roughness k mm 0.015
friction factor From Moody's Chart
Length of the branch of dia 2 Lbr 12.500
friction factor From Moody's Chart Length of the branch of dia 3 Lbr 30.000
Valve loss coefficient Kv 0.300
12 Monthly Flow
Jan 3.57 Poush (m3/s) 3.75
Feb 3.23 Magh (m3/s) 3.38
Mar 3.21 Falgun (m3/s) 3.08
Apr 3.86 Chaitra (m3/s) 3.34
May 6.85 Baishakh (m3/s) 4.38
Jun 17.13 estha (m3/s) 9.31
Jul 32.54 Ashar (m3/s) 24.95
Aug 37.73 Shravan (m3/s) 40.12Sep 28.39 Bhadra (m3/s) 35.34
Oct 15.69 Ashoj (m3/s) 21.44
Nov 7.70 Kartik (m3/s) 9.94
Dec 4.60 Mangsir (m3/s) 5.45
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NYADI HYDROPOWER PROJECT, FEASIBILITY STUDY
POWER AND OUTPUT ENERGY CALCULATION
Gross head, m 347.50 m
Overall efficiency 85.47%
Dry season outage 4%
Wet season outage 4%
D/s release m3/s 0.31 m
3/s
Length of tunnel 3937.0 m
Shotcreted tunnel 2737.0 m 90.50% 97.00% 99.50% 87.35
Concrte lined tunnel 1200.0 m 89.00% 97.00% 99.00% 85.47
Length of penstock 675.4 m
Manning's coefficient 0.015 For concrete
Friction coeficient 0.022 For shotcrete
Tunnel Diameter 3.20 m Area 9.14 m2
Height to the stringer 1.60 m Perimeter 11.43 m
Month
(Nepali)
Nyadi
Intake Flow
Available
flow in Siuri
Flow
available in
Siuri
Tailrace
Available
Flow
Operating
daysDesign flow
Headloss
HW
Headloss
HRT
Headloss
Penstok
Total
HeadlossNet head
Generation
capacity
Dry sea
energ
(m /s) (m3/sec) (m /s) (m /s) (m /s) m m m m m (kW) (kW
Baishakh 4.38 0.68 0.64 4.71 31 4.71 0.155 0.571 1.144 1.871 345.63 13642.61
estha 9.31 1.62 1.40 10.40 31 10.40 0.756 2.791 5.589 9.136 338.36 29516.00
Ashar 24.94 3.87 1.40 26.04 32 11.08 0.857 3.165 6.339 10.361 337.14 30000.00
Shravan 40.12 7.46 1.40 41.21 31 11.08 0.857 3.165 6.339 10.361 337.14 30000.00
Bhadra 35.34 7.83 1.40 36.43 31 11.08 0.857 3.165 6.339 10.361 337.14 30000.00
Ashoj 21.44 4.62 1.40 22.54 31 11.08 0.857 3.165 6.339 10.361 337.14 30000.00
Kartik 9.94 2.28 1.40 11.04 30 11.04 0.850 3.141 6.289 10.280 337.22 30000.00
Mangsir 5.45 1.36 1.32 6.46 29 6.46 0.291 1.077 2.156 3.525 343.98 18637.11
Poush 3.75 1.04 1.00 4.44 30 4.44 0.138 0.509 1.019 1.665 345.83 12879.31 8,9
Magh 3.38 0.79 0.75 3.82 29 3.82 0.102 0.376 0.753 1.230 346.27 11084.67 7,4Falgun 3.08 0.58 0.54 3.31 30 3.31 0.077 0.283 0.567 0.926 346.57 9626.65 6,6
Chaitra 3.34 0.43 0.39 3.42 30 3.42 0.081 0.301 0.602 0.985 346.52 9922.77 6,8
Maximum Power Generation, kW
Total seasonal Energy, kWh 29,8
Annual generation, GWh
Total energy, GWh
Ratio of wet season energy with dry season energy
Penstock Diameter, m
40.00%
11.08
1.75
OverTurbine Gen. Transformer
Probability excedence, %
Design flow, m3/s
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GEOTECHNICAL DESIGN
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UNDERGROUND STRUCTURES
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APPENDIX E
OPTIMIZATION STUDY
NYADI HYDROPOWER PROJECT
FEASIBILITY STUDY
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Tables of Contents
1. plant capacity optimization ..................................................................................................... 2
1.1 Introduction ..................................................................................................................... 2
1.2
Objectives ........................................................................................................................ 2
1.3 Approach and Methodology ............................................................................................... 2
1.4 Hydrology ........................................................................................................................ 3
1.5 Plant Capacity Ranges ........................................................................................................ 3
1.6 Conceptual Layout ............................................................................................................ 4
1.7 Energy Production ............................................................................................................. 6
1.8 Cost Estimate ................................................................................................................... 6
1.9 Benefit Cost Analysis for Various Installed Capacities........................................................... 7
1.10 Result of Benefit Cost Analysis ........................................................................................... 8
1.11 Conclusion and Recommendation ...................................................................................... 8
List of table and Figures
Table 1.1 Intake site average monthly flows in m3/s ........................................................................... 3Table 1.2 Plant Capacity Ranges ............................................................................................... 3
Table 1.3 Project Structures Details ................................................................................................. 5Table 1.4 Energy Production........................................................................................................... 6Table 1.5 Comparison of the base project costs for various installed Capacities.................................. 7Table 1.6 Financial Indicators for various installed capacities ............................................................. 8
Figure 3-1-1 Optimization Curves EIRR Vs percentage exceedance ..................................................... 8
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1.
PLANT CAPACITY OPTIMIZATION
1.1
Introduction
The plant capacity is dependent primarily on the discharge in the river if other factors are pre-assumedto be constant. Discharge of varying exceedance is required for determining the size of structures whichultimately impact on the associated costs and benefits. Thus this optimization chapter deals with thestudy of comparative costs and benefits of various discharges of varying exceedance flows in order todetermine the most economical installed capacity of the plant.
1.2
Objectives
The main objective of optimization is to determine the optimum plant capacity at which the dischargewill produce maximum benefit. The benefit is revenue from sales of the generated energy of the powerplant. It is a comprehensive analysis of cost benefits analysis and fixing the optimum capacity of project.
1.3
Approach and Methodology
The selection of the optimum plant capacity is determined from the economic and financial indicatorssuch internal rate of return, benefit cost ratio and optimum utilisation of natural resources.
The Nyadi Khola is a steep River with perennial discharge and gross head available within the study areais sufficient to produce power ranging from 18.50 MW to 50.10 MW. From the flow duration curve asdiscussed in section 2.3, it has been determined that the discharges available to divert at the intake varyfrom 6.74 m3/sec to 18.50 m3/sec (including the tailrace water of Siuri Hydroelectric Project) for theoptimization purpose which would produce plant capacities from 18.50 MW to 50.10 MW respectively.In general practice, more discharge is diverted than design discharge for flushing, which will not considerfor optimization purposes. It was assumed that plant capacity below and above these discharges would
yield relatively lower returns, therefore the optimization study was limited to the above range.The procedure followed for each option during the optimization is described below:
1. Determination of conceptual layout of the scheme.
2. Determination of discharge options (as explained above) based on hydrology of the river atheadworks and additional flow available from Siuri tailrace.
3. Determination of gross head of the scheme.
4. Preliminary design of the structures like weir with orifice type frontal intake and bottom sluicewith two radial gates, gravel trap, intake tunnel, settling basin with flushing arrangement, surgeshaft, underground powerhouse with access tunnel and tailrace tunnel and Provision of tapping
Siuri tailrace flow.
5. Determination of optimum size of headrace tunnel and penstock pipe.
6. Determination of head loss and computation of energy based on the diversion discharge.
7. Determination of the cost of individual structure and the total cost of the project.
8. Computation of benefit-cost analysis and determination of financial indicators for each option.
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1.4
Hydrology
Hydrology is the prime factor on which energy and revenue are based. The main purpose of theoptimization is to determine the optimum discharge from techno-economic point of view. Theoptimization has been carried out based on mean daily flow available in the river. Long-term averagemonthly flow of Nyadi intake is calculated by correlating with flow data (DHM) of Seti River, gauge
reading data of Nyadi HP and available flow data in Siuri tailrace (as per feasibility report of Siuri SHP),which are presented in Table 1.1.
Table 1.1 Intake site average monthly flows in m3/s
Month Nyadi at intake
(m3/sec)
Siuri Tailrace
(m3/sec)
Combined discharge(m3/sec)
Baishakh 4.38 0.64 5.02
J estha 9.31 1.40 10.71
Ashar 24.95 1.40 26.35
Shravan 40.12 1.40 41.52
Bhadra 35.34 1.40 36.74
Asoj 21.44 1.40 22.84
Kartik 9.94 1.40 11.34
Mangsir 5.45 1.32 6.77
Poush 3.75 1.00 4.75
Magh 3.38 0.75 4.13
Falgun 3.08 0.54 3.62
Chaitra 3.34 0.39 3.73
There will be downstream riparian release of 10% of the minimum mean monthly flow for fish andaquatic life which is equivalent to 0.31 m3/sec.
1.5
Plant Capacity Ranges
For optimization, different options are determined for probability of exceedance flow ranging from 30%to 50%. It is obvious that lower the probability of exceedance, the higher will be the plant capacity andhence higher energy generation. It is however not mandatory that the highest plant capacity will be mostoptimum scheme. Thus, the ranges of plant capacities were determined by the design discharge atvarious probabilities of exceedance, the corresponding net head and overall efficiency (85.47%). Theplant capacity for different probability of exceedance have been presented and listed in Table 1.2.
Table 1.2 Plant Capacity RangesPlant
capacity(MW)
Rated Discharge
(m3/s)
Probability of
exceedance (%)
Gross Head
(m)
Head loss
(m)
Net Head
(m)
18.50 6.74 50 333.90 5.76 328.13
22.40 8.16 45 333.90 5.63 328.27
30 11.08 40 333.90 10.36 323.54
36.30 13.26 35 333.90 7.351 326.59
50.10 18.50 30 333.90 10.66 323.24
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1.6
Conceptual Layout
The concept of the project layout is proposed to maximize the discharge and head within the projectboundary. The headworks area lies at upstream of the confluence of Nyadi and Siuri Khola. Tailracewater of Siuri Khola Hydropower Project is also used in this project along the left bank of the NyadiRiver via pumping mechanism.
The headworks structures will comprise of concrete diversion weir with bottom sluice and two radialgates, frontal intake with orifices, gravel trap and intake tunnel. All of these structures lie on the rightbank of the Nyadi Khola. There will be two bifurcating tunnels to feed the diverted water tounderground settling basins with flushing arrangement. Then, discharge will be passed through 3,937mlong headrace tunnel following the ridge of the hill Sangla and Nana village. A surge shaft with surge shaftadit will be provisioned at the end of Headrace tunnel near Nana village. Steel penstock pipe withsurface penstock and drop shaft will connect the headrace tunnel with underground powerhouselocated inside the hill on the right bank near Thulobeshi village. The powerhouse comprises of threeunits of horizontal axis pelton turbines, generators, transformers and other necessary accessories. Aswitchyard located at foot of the hill on the right bank close to powerhouse will connect to 132 kVTransmission lines of length of about 7km which will evacuate the generated electricity to the proposed
NEA Hub at Tunikharka.A 10.50 km long access road is required to connect the headworks with powerhouse and existingBesishahar- Chame road at Thakanbeshi at the right bank of the Marsyangdi River. Additionally, 3 kmlink road will be required to connect surge adit outlet from the road to Headworks. Besides, a 52 mlong bridge has been proposed to connect the two sides of the Marsyangdi River along the roadalignment at Thakanbeshi. The details of structures for each of the options are presented in Table 3.3.
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Table 1.3 Project Structures Details
Description 18.50 MW 22.40 MW 30.00 MW 36.30 MW 50.10 MW
Weir Crest Level 1381.50 masl 1381.50 masl 1381.50 masl 1381.50 masl 1381.50 masl
Weir Crest Length 14 m 14 m 14 m 14 m 14 m
Weir Type Concrete Weir Concrete Weir Concrete Weir Concrete Weir Concrete WeirBottom Sluice Unit Two Two Two Two Two
Intake Frontal withorifice
Frontal withorifice
Frontal withorifice
Frontal withorifice
Frontal withorifice
No. of Orifice 2 3 3 4 4
Orifice Size 2.25m*3.50m 2.25m*3.50m 2.25m*3.50m 2.25m*3.50m 2.25m*4.50m
Intake Tunnel 57m*2.4m*2.4m 57m*2.6m*2.6m 57m*3m*3m 57m*3.4m*3.4m 57m*4m*4m
Settling BasinCavern
84m*8m*8.50m 101m*8m*9m 128m*8m*10.3m 165m*8m*11.3m 230m*8m*12.8m
Headrace TunnelLength
3981 m 3964 m 3937m 3900 m 3835m
Headrace TunnelDiameter
3.2m 3.2m 3.2 m 3.5 m 3.8m
Surge Shaft Height 26.26m 27.63 m 29.66m 32.08 m 32.64mSurge ShaftDiameter
5m 5m 5m 5m 5m
Surface Penstock 476 m 476 m 476 m 476 m 476m
Drop Shaft andHorizontal parts
200m 200m 200m 200m 200m
Diameter 1550mm 1750mm 1750mm 2150mm 2250mm
Average Thickness19.00 mm 19.00mm 19.00mm 22.00mm 22.00mm
Powerhouse U/G U/G U/G U/G U/G
Turbine Type Horizontal AxisPelton Turbine
Horizontal AxisPelton Turbine
Horizontal AxisPelton Turbine
Horizontal AxisPelton Turbine
Horizontal AxisPelton Turbine
No of Units 3 nos. 3nos. 3nos. 4nos. 4nos.
PowerhouseCavern Size (B*L) 12m*53 m 14m*53 m 14m*53 m 15m*64 m
15m*64 m
Tailrace Tunnel(L*B*H)
225.85m*3.2m*3.2 m
225.85m*3.4m*3.4m
225.85m*3.6m*3.6m
225.85m*3.8m*3.8m
225.85m*4.2m*4.2m
Access road 13.5 KM 13.5 KM 13.5 KM 13.5 KM 13.5 KMBridge Over
Marsyangdi River52m 52m 52m 52m 52m
Transmission Line 132kV, 7 KM,NEA Hub
132kV, 7 KM,NEA Hub
132kV, 7 KM,NEA Hub
132kV, 7 KM,NEA Hub
132kV, 7 KM,NEA Hub
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1.7
Energy Production
Based on the net head, turbine discharge and overall efficiency of the plant, the energy production in ayear has been calculated. An outage of 4% has been estimated for transmission loss, self consumptionand plant shut down during maintenance periods. Estimated power consumption for rural electrificationin project affected area is 0.09 GWh in dry season and 0.18 GWh in wet season. Estimated power
consumption for pumping of Siuri tailrace water is 0.99 GWh in dry season and 0.79 GWh in wetseason. After deduction of total energy for rural electrification and pumping of Siuri tailrace water, netenergy available for sale has been calculated and tabulated below.
Table 1.4 Energy Production
Plant Capacity 18.50 MW 22.40 MW 30MW 36.30 MW 50.10 MW
Total Energy generation(GWh) after deduction of 4%outage
128.97 145.97 177.30 192.40 223.01
Energy for rural
electrification (GWh)
0.27 0.27 0.27 0.27 0.27
Energy for pumping (GWh) 1.78 1.78 1.78 1.78 1.78
Net Energy available for sale(GWh)
126.92 143.92 175.25 194.45 234.06
1.8
Cost Estimate
The cost components for various capacities on varying exceedance flow are estimated as per thefeasibility level design. The size and crest elevation of weir structures remains same in the various
discharge, but nos. and size of intake orifice opening is changed as per the design discharges of variousexceedance flows. The size of gravel trap, intake tunnel and underground settling basin change withdischarges of different option, which have significant impact on the total project cost of various options.From the recent technological development and practices, the tunnel with diameter of around 3.2 m canbe mechanically constructed with proper working space and ventilation. Therefore, same size of tunnelis adopted for discharge with the exceedance 40% to 50%. But headrace tunnel size is found optimumfor higher discharge based on cost and revenue loss. The size of surge shaft increases with discharge ofvarious capacities and cost of each capacity estimated separately.
Penstock diameter increases with increase of discharge and has significant impact on the total projectcost. Although an increase in penstock pipe diameter raises initial cost, the energy output will beincreased due to reduction of headloss. So, the penstock is optimized for most cost effective
combination of the penstock diameter and thickness. Penstock pipe was adopted for correspondingdischarges and associated costs. The thickness of each penstock pipe has been estimated. The cost ofanchor blocks and support piers are slightly affected by change in discharge and diameter of thepenstock which is estimated accordingly.
Other hydro-mechanical costs like radial gates, bulk head gates, stoplogs, and trashrack etc have beenestimated as per the prevailing market rate.
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Based on design discharge and rated head, the type and size of turbine are calculated. Sizes ofpowerhouse caverns are determined accordingly. Then the cost estimate of powerhouse of each optionis estimated accordingly. The cost of electro-mechanical parts including turbine, governor, generator,transformers, etc. are estimated based on prevailing practice and market prices.
The estimated base costs of project include transportation, installation and custom duties as well as
other applicable taxes. Similarly the cost of transmission line has been estimated based on per kilometrecost of construction of 132kV transmission line and it also includes interconnection arrangement atdelivery location. Other cost like tapping of tailrace water of Siuri SHP, access road, environmentalmitigation, land acquisition, infrastructures, owner development cost and contingencies have beenproportionately increased for the respective plant capacities
Table 1.5 Comparison of the base project costs for various installed Capacities
1.9
Benefit Cost Analysis for Various Installed Capacities
The different options with various plant capacities and their corresponding construction costs andbenefits are compared by financial analysis based on discounted cash flow. Financial analysis has beenperformed to find the capacity at which the benefits are maximized. The analysis is carried out inNepalese Rupees (NRs.) as the price for the energy that will be sold from this project to the bulk power
50.10 MW 36.30 MW 30.00 MW 22.40 MW 18.50 MW
Civil works 34.94 26.70 23.87 21.53 21.05
Electromechanical works 19.16 14.15 10.33 8.95 7.75
Penstock and Hydromechanical works 3.86 3.66 3.26 3.15 2.88
Transmission line works 1.35 1.35 1.35 1.35 1.35
Marsyangdi Bridge and Access Road 2.47 2.47 2.47 2.47 2.47
Siuri Tailrace Flow Diversion 1.41 1.41 1.41 1.41 1.41
Socio-environmental mitigation costs 0.91 0.68 0.45 0.45 0.45
Infrastructure development costs 1.79 1.23 1.02 1.02 1.02
Land acquisition and direct costs 0.54 0.54 0.54 0.54 0.54
Rural Electrification Costs 0.37 0.37 0.37 0.37 0.37
Total contact cost 66.80 52.56 45.06 41.24 39.30
Engineering fees 5.34 4.20 3.61 3.30 3.14
1.5 % insurance,tax and 10% VAT 7.48 5.92 5.22 4.81 4.66
Owner's development cost 3.08 2.82 2.15 2.15 2.15
Total Project cost for year 2010 82.70 65.50 56.04 51.50 49.25
Total Project cost for year 2011 based on price escalation @ 5 p.a. 86.84 68.77 58.84 54.08 51.71
Summary of project contract costs for various installed capacities
Amout in US$ Milion
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purchaser after finalizing the power purchase agreement (PPA). The relevant specific parameters appliedfor the financial analysis in this study are adapted as given in section 15.2.
1.10
Result of Benefit Cost Analysis
Financial indicators such as IRR on equity and IRR on Project for various installed capacities are shownin Table 1.6 . IRR on equity versus percentage exceedance are shown in figure 3-1.
Table 1.6 Financial Indicators for various installed capacities
Descriptions 18.50 MW 22.40 MW 30MW 36.30 MW 50.10 MW
IRR on Equity 11.28% 13.63% 17.13% 15.47% 14.12%
IRR on Project 13.67% 15.04% 16.995 16.08% 15.32%
Figure 3-1-1 Optimization Curves EIRR Vs percentage exceedance
1.11
Conclusion and Recommendation
Based on the financial analysis of all the options corresponding to different exceedance flow, the projecthas been found to be optimized at 30 MW corresponding to 40% exceedance.
Thus project engineering works (design and drawings), quantity estimation, costing and financial analysishave been carried out for 30 MW.
11.28%
13.63%
17.13%
15.47%
14.12%
10.00%
11.00%
12.00%
13.00%
14.00%
15.00%
16.00%
17.00%
18.00%
25 30 35 40 45 50 55
EIRR
PERCENTAGEEXCEEDANCE(%)
EIRR
Vs
Percentage
Exceedance
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APPENDIX F
COST ESTIMATE AND
FINANCIAL ANALYSIS
NYADI HYDROPOWER PROJECT
FEASIBILITY STUDY
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TABLES OF CONTENTS
F. COST ESTIMATE AND FINANCIAL ANALYSIS................................................................ 2
F.1 Cost estimate....................................................................................................................................................... 2F.1.1 Preliminary site works ................................................................................................................................ 2
F.1.2 Main civil works............................................................................................................................................ 2F.1.3 Mechanical and electrical ........................................................................................................................... 2F.1.4 132 kV transmission line ............................................................................................................................ 3
F.2 Engineering fees .................................................................................................................................................... 3F.3 VAT and taxes ...................................................................................................................................................... 3F.4 Contingency sums ................................................................................................................................................ 3F.5 Benefit Calculation ............................................................................................................................................... 3
List of Tables
Table F 1. Project cost summary ...................................................................................................................................... 4Table F 2. Owners direct cost .......................................................................................................................................... 5Table F 3. Land acquisition cost ........................................................................................................................................ 6
Table F 4. Access road and Marsyangdi Bridge cost .................................................................................................... 7Table F 5. Infrastructure development costs ................................................................................................................. 8Table F 6. Civil Works Cost .............................................................................................................................................. 9Table F 7. Hydro mechanical cost .................................................................................................................................. 15Table F 8. Electromechanical cost .................................................................................................................................. 16Table F 9. Transmission line and intergrid connection cost ..................................................................................... 17Table F 10. Environmental monitoring and mitigation cost ...................................................................................... 18Table F 11. New rate summary ....................................................................................................................................... 19Table F 12. Rate summary of Miscellaneous Item ....................................................................................................... 23Table F 13. Tunnel Excavation Rate ............................................................................................................................... 24Table F 14. Energy Calculation Sheet of NHP ............................................................................................................. 25Table F15. Benefit Calculation sheet of NHP.....................................................................................................................26
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F. COST ESTIMATE AND FINANCIAL ANALYSIS
F.1 Cost estimate
The total project cost for year 2011 is presented in Table F1.The detailed cost estimate for different packagesare presented in Tables F 2 to F 10. New rate summary is given in Table F 11. Other assumptions on whichthe estimate is based are indicated below.
The cost estimate has been split into five cost packages. The packages are as follows:
Contract C1 Preliminary site works
Land Acquisition
Access road
Bridge over Marsyangdi
Temporary and permanent Housing
Contract C2 Main civil works
Contract C3 Elect mechanical
Contract C4 Penstock and Hydro-mechanicalContract C5 132 kV transmission line
F.1.1 Preliminary site works
This contract contains the items necessary to expedite the work in the initial stage which is preliminary civilworks including the permanent access road, preparation of construction areas, housing for this phase, offices,water supplies, sewage disposal. The program critical path items are Bridge over Marshyangdi and the accessroad.
F.1.2 Main civil works
Contract C2 comprises the main civil works including the Headworks, waterway including surge shaft and
vertical shaft, underground powerhouse, tailrace tunnel, access tunnel and switchyard.
The following assumptions have been made:
The average tunnelling rate for the headrace tunnel is minimum 15 m to maximum 25 m per week
The unit rates are developed based on the experience of other similar projects in Nepal.
Water supply
Total daily volumes of water demands are based on experience at Khimti Hydropower Project. Water supplycosts allow for chlorinating at each major site and have a nominal allowance for simple water treatment (e.g.roughing filter). Water supply costs are order of cost only and would need to be verified after further design.
Sewerage
The cost allows for sewer collection system, septic tank and soaks away trenches. At the Headworkshowever, given the steep and rocky ground, septic effluent disposal by conventional trenches is consideredproblematic. Therefore an allowance for a package treatment plant to treat septic tank effluent is included.
F.1.3 Mechanical and electrical
The cost includes supply and installation of all the mechanical and electrical equipment from the powerhouseto the outdoor switchyard.
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Steel penstock
Costs are based on budget cost advice from Nepal Hydro Electric (NHE) in Butwal.
F.1.4 132 kV transmission line
This cost package includes the erection of the switchyard electrical items and the 132 kV line andcommissioning of the line.
The following assumptions have been made:
There will be no NEA charge for connecting the 132 kV line into the grid at proposed NEAs Hubat Tunikharka.
Steel Type towers are used in the cost estimate
F.2 Engineering fees
The 8% engineering fees are assumed to cover the additional studies described in Section 13.4, Volume 1,main report, the hydraulic model study , all detailed design and including construction supervision by a local
Consultant.
F.3 VAT and taxes
The amount of VAT payable has been based on assumed Nepal currency expenditure percentages of totalcontract values. This is indicated in Table F.1. VAT is assumed to 13%. Tax deducted at source is assumedpayable on engineering fees at 5%.
F.4 Contingency sums
A general sum of 10% has been included on contract C1, C2 and C4 and 8% has been included in C3 and C5.A higher sum of 10% has been included on the C2 main civil works contract to cover the higher risk of theunderground works. However, 5% contingencies sums are taken in preliminary site works.
F.5 Benefit Calculation
The basis for the benefit calculation is the adopted hydrological parameters and possible tariff rates of theenergy which could be agreed while reaching PPA.
Annual dry and wet energy production in a normal year are calculated based on the adopted hydrological data.Allowance is made for downstream release (10 % of the driest mean monthly flow) while estimating theenergy production. Planned and forced outages are considered as 4 % for both wet and dry seasons. Themonthly energy estimate is carried out based on average monthly flow. The estimated monthly energyproduction in a normal year after deducting energy for rural electrification and pumping for the base case issummarized in Table F 14.
While calculating the energy benefit in terms of money, the flat tariff rates (base case) of 6.30 NRs/kWh have
been assumed for both dry and wet energy with 6 % escalations per annum up to 10 years period aftercommissioning date of the project. Details of the benefit calculations based on project base cost for year 2011are presented in Table F15.
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Table F 1. Project cos tsummary
Exchange Rate (US$) 75
Installed capacity 30.0 MW
SUMMARY OF DIFFERENT
CONTRACT COSTS % NRs US$ NRs Total US$ Total
VAT
complying
VAT complying
NRs equivalent
Item
Allocations
Civil works 337,075,604 17,203,070Contingency sum 10 33,707,560 1,720,307
Sub - Total 370,783,164 18,923,377 81% 1,449,929,510 42.59%
Electromechanical works 9,560,289
Contingency sum 8 764,823
Sub - Total 10,325,112 8% 61,950,673 18.42%
Penstock and Hydromechanical works 109,701,337 1,497,023
Contingency sum 10 10,970,134 149,702
Sub - Total 120,671,471 1,646,725 44% 106,216,494 5.81%
Transmission line works 35,272,100 780,401
Contingency sum 8 2,821,768 62,432
Sub - Total 38,093,868 842,833 100% 101,306,375 2.41%
Marsyangdi Bridge and Access Road 134,441,099 449,509
Contingency sum 10 13,444,110 44,951
Sub - Total 147,885,209 494,460 100% 184,969,677 4.40%
Siuri Tailrace Flow Diversion 16,225,634 1,065,773
Contingency sum 10 1,622,563 106,577
Sub - Total 17,848,197 1,172,351 56% 59,233,723 2.52%
Socio-environmental mitigation costs 32,324,000
Contingency sum 5 1,616,200
Sub - Total 33,940,200 100% 33,940,200 0.81%
Infrastructure development costs 41,730,729 419,602
Contingency sum 5 2,086,536 20,980
Sub - Total 43,817,266 440,582 100% 76,860,923 1.83%
Land acquisition and direct costs 38,416,858
Contingency sum 5 1,920,843
Sub - Total 40,337,701 0% 0 0.96%
Rural Electrification Costs 28,000,000 28,000,000 0% 0 0.67%
TOTAL CONTRACT COSTS SEPARATE 841,377,075 33,845,440
TOTAL CONTRACT COSTS US$ 45,063,801
ENGINEERING FEES 8 3,605,104 100% 270,382,806 6.43%
TOTAL CONTRACTS & ENGINEERING COST US$ 48,668,905 2,344,790,381
1.5 % INSURANCE COST 0.015 730,034
Sub- Total (A) 49,398,939
TOTAL VAT COMPLYING US$ EQUIVALENT
VAT 13 4,064,303
TDS on Engineering fees 1.5 54,077
Total Taxes (1% custom duty & 0.1%
godown charge ) 1.1 372,300
TOTAL TAX AND VAT (B) 4,490,680
TOTAL CONTRACTS & ENGINEERING COST INC. VAT & TDS 53,889,618
Owner's development costs 2,149,590
TOTAL PROJECT COST (Nearest $1000) for 2010 56,040,000
Cost escalation@5% p.a. 5% 2,802,000
TOTAL PROJECT COST (Nearest $1000) for 2011 58,842,000
Notes:
Unit rates are based at the site local to construction. 1,961 per KW
Unit rates include cost of labour plant and materials
Contingency sum cover forseen and unforseen risks. It does not cover cost overrun.
Risks - ground conditions, strikes, material shortage, political instability, delay in license, manpower shortage
Unit Cost US$
Nyadi Hydropower Project (NHP)
PROJECT COST ESTIMATE
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Table F 2. Owners direct cost
Nyadi Hydropower Project
Owner's Direct cost
Rate for US$/NRs 75
S.N. Description of Items Units Nos. QuantityRate
(US$)
Amount
(US$)1 Feasibility Study 1 L.S. 106,670.00 106,670.00
2Detail design including tender docpreparation
1 L.S. 400,000.00 400,000.00
2 Office Setup
2.1 Office building rent months 1 48 270.00 12,960.00
2.2 Salary for personnel
2.2.1 Project Director months 1 48 3,500.00 168,000.00
2.2.2 Resident Project Manager months 1 48 1,800.00 86,400.00
2.2.3 Planning,Account/Admin, Contract Manager Months 3 48 1,500.00 216,000.00
2.2.4 Engineers/geologist/mitigation officer months 8 48 1,000.00 384,000.00
2.2.5 Peons months 5 48 250.00 60,000.00
2.2.6 Guard months 4 48 250.00 48,000.00
2.2.7 Secretary months 2 48 250.00 24,000.00
2.2.8 Drivers months 6 48 245.00 70,560.00
3 Vehicle Nos. 6 1 50,000.00 300,000.00
4 Office furniture L.S. 30,000.00
5 Owner's Overhead L.S. 50,000.00 50,000.00
6 Site Security
Officers months 6 40 200 48,000.00
Assistants months 20 40 125.00 100,000.00
7 Housing and facilities L.S. 45,000.00 45,000.00
Total Cost 2,149,590.00
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Table F 3. Land acquisition cost
Nyadi Hydropower Project (NHP)
LAND ACQUISITION AND COMPENSATION COST
Description Unit QuantityAmount
(NRs) Remarks
Land purchased Upto 27 July,2010
Access road Ropani 130 7,373,356.00
Hydropower components Ropani 308 19,651,728.00
Total 27,025,084.00
Remaining Land to be purchased
Require private land for access road Ropani 16 814,052.80
Required land for Powerhouse, TailraceSwitchyardRopani
5 671,601.00
Staff housing area at powerhouse site Ropani 4 116,913.00
Vertical tunnel, penstock alignment, surgeshaft, Road for surge shaft, spoil tip area ofsurge adit area
Ropani
9 1,689,207.00
Staff housing area at intake site Ropani 20 2,900,000.00
Required land for Adit tunnel in Naiche Ropani 10 1,450,000.00
Transmission line Ropani 25 3,750,000.00
Total 11,391,773.80
Total Amount 38,416,857.80
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Table F 4. Access road and Marshyangdi Bridge cost
]
Nyadi Hydropower ProjectBailey Bridge and Access Road Cost
1 US$ 75 NRs.
Description Unit Quantity Rate(US$) Rate (Nrs)Amount
(US$)Amount (Nrs) Remarks
MarsyangdiBridge
Reference from contractto be signed
Civil works 1 2,517,784.00
Bailey Bridge withComplete fitting 1 992,000.00 137,027.20
Sub Total20% contribution by SiuriSHP
Access road
Total Length Km 13.500 28,933.473 12,215,121.73 312,481.51 131,923,315Reference from Boq ofAccess road
Sub Total 20% contribution by SiuriSHP
Total 449,508.71 134,441,098.67
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