080811 planning and design of l.i.s.s

08.08.2011 NAC, HYDERABAD 1

PLANNING & DESIGN OF LIFT IRRIGATION SCHEMES

B.LAKSHMANA RAO, B.Tech., M.B.A., F.I.E.,Joint Secretary (Tech)& Chief Engineer, Srisailam Project,

I&CAD Dept., Hyderabad09177908811 --- [email protected]


PROJECT WISE AYACUT IRRIGATED IN KHARIF 2010-11 and proposed in Rabi 2010-11

Area in acres Area in acres

Sl.No Name of the Project Total Aycut

Ayacut Irrigated in Kharif

Ayacut Proposed for Rabi

Sl.No

Name of the Project

Total Aycut

Ayacut Irrigated in

Kharif

Ayacut Proposed for

Rabi

1 2 3 5 6 1 2 3 5 6

1 Nagarjuna Sagar 2153094 2117000 621000

20Godavari Delta System 1038362 986000 896000

21Krishna Delta System 1335100 1300000 524000

2A.M.R.P (SLBC) 195521 184539 22Yeleru 67614 53000 530003Musi 30000 30000 23Vamshadhara 226199 147000 4Priyadarshini Jurala 107143 116000 68500 24Tarakarama LIS 4563 4563

5R.D.S 87183 30000 10500 25Gundlakamma Project 40000 5000

6Nizamsagar 231339 190000 190000 26Tadipudi LIS 100000 125000 7S.R.S.P-1 956548 632640 887022 27Kovvadakalva 15000 15000 8S.R.S.P-2 160000 75000 28Chagalnadu 35614 20000 9J.C.Rao DLIS 20000 45000 29Pushkara LIS 86094 34127 10Kaddam 68849 68000 34500 30Venkatanagaram 34000 2250 11TBP HLC 313400 80000 31Surampalem 14150 14150

12TBP LLC 151134 168000 39000 32Pennar Delta System 247000 247000 247000

13K.C.Canal 287400 265628 111754 33Somasila Project 176000 176000

14S.R.B.C 183936 123076 30000 Major Irrigation Total 8899334 7342882 4067276

15Telugu Ganga 400110 115000 115000 Medium Irrigation 837518 570215 104655

16Guru Raghavendra 3793 3793 Minor Irrigation 4669650 2350000 65000017Thandava Reservoir 51466 45068 30000 APSIDC 899503 595769 18Narayanapuram Anicut 39178 35898 30000 Grand TOTAL 1.5E+07 10858866 482193119Nagavali 39544 39150 30000

08.08.2011 NAC, HYDERABAD 3WALAMTARI, HYDERABADWALAMTARI, HYDERABAD 33

AYACUT DETAILS UNDER L.I.SCHEMES

PUSHKARA L.I.S. - 1,85,906 Ac TADIPUDI L.I.S. - 68,600 Ac RAJIV SAGAR L.I.S. - 4,00,000 Ac ALISAGAR L.I.S. - 53,793 Ac GUTPAH L.I.S. - 38,793 Ac RAJIV BHIMA L.I.S. - 2,03,000 Ac NETTAMPADU L.I.S - 2,00,000 Ac KALWAKURTHY L.I.S. - 3,40,000 Ac H.N.S.S. L.I.S. - 6,21,000 Ac


Introduction Rain is decentralized and so is the demand but the

supply has not been decentralized

Prevailing situation is widening socio-economic

conditions between regions resulting imbalance.

There are regions situated at higher altitudes to

which gravity is not possible or site conditions at

source do not permit dam / barrage

Lift irrigation schemes gained greater significance

in the changed scenario as provision of conventional

irrigation structures is exhausted.


Dams & Barrages have problems of :Dams & Barrages have problems of :

SubmersionSubmersion Rehabilitation Rehabilitation Land AcquisitionLand Acquisition Environment ClearanceEnvironment Clearance Inter-state disputesInter-state disputes Most important they consume more time for completion. Most important they consume more time for completion.

Major irrigation structures need huge financial support Major irrigation structures need huge financial support and and often the estimated cost gets multiplied due to often the estimated cost gets multiplied due to delay in the completiondelay in the completion. .


Reasons for Opting Lift Schemes Over Gravity SchemesReasons for Opting Lift Schemes Over Gravity Schemes:: In the present circumstances, In the present circumstances, lift irrigation schemes assumed lift irrigation schemes assumed

greater significance and seems to be the only viable solutiongreater significance and seems to be the only viable solution to to meet the aspirations of the upland people for the following reasons :meet the aspirations of the upland people for the following reasons :

Speedy Completion of the SchemeSpeedy Completion of the Scheme Lesser initial CostLesser initial Cost No need of extensive and time investigationNo need of extensive and time investigation Flexibility of Location of Head worksFlexibility of Location of Head works Does not have foundation problemsDoes not have foundation problems Environmental friendlyEnvironmental friendly

Though lift irrigation schemes have some drawbacks and are costly, Though lift irrigation schemes have some drawbacks and are costly, in the prevailing situation, they are inevitable since the situation in the prevailing situation, they are inevitable since the situation demands them in the contemporary irrigation planning, but ought to demands them in the contemporary irrigation planning, but ought to be taken up judiciously.be taken up judiciously.


Limitations of L.I. Scheme Limitations of L.I. Scheme They are costly with respect to benefit cost ratio They are costly with respect to benefit cost ratio

compared to Gravity schemes compared to Gravity schemes Require assured un-interrupted power supply. Always Require assured un-interrupted power supply. Always

dependent on power supplydependent on power supply Require assured flows from the sourceRequire assured flows from the source Recurring cost on power billsRecurring cost on power bills Regular maintenance is required for civil as well as Regular maintenance is required for civil as well as

mechanical works. Any problems in pipes or pumps lead mechanical works. Any problems in pipes or pumps lead to grinding halt to the system to grinding halt to the system

Life of L.I. scheme is shorter than dams & barragesLife of L.I. scheme is shorter than dams & barrages Need periodical replacement of mechanical & electrical Need periodical replacement of mechanical & electrical

components components


Objectives of LI Schemes

Diversion of flood water to upland areas

Supplying water to needy regions located far away

from source

Feeding tanks for future needs

Effective usage of water stored in reservoirs

Optimum utilization of water by supplying designed

quantity

Interlinking of rivers

Transfer of surplus water from reservoirs to the

required regions.


VARIOUS COMPONENTS OF LI SCHEMESVARIOUS COMPONENTS OF LI SCHEMES

I) Civil Structure & Associated components / I) Civil Structure & Associated components / provisionsprovisions

II ) Electro-Mechanical andII ) Electro-Mechanical and

III) Hydro-MechanicalIII) Hydro-Mechanical


I) Civil Structure & Associated components / I) Civil Structure & Associated components / provisionsprovisions

Approach CanalApproach Canal Intake / Sump / Fore bay / Surge poolIntake / Sump / Fore bay / Surge pool Sub structure / sumpSub structure / sump Super structure to accommodate Pumps & MotorsSuper structure to accommodate Pumps & Motors Service / maintenance bayService / maintenance bay Control panel roomControl panel room Dewatering Pumps chamber arrangementDewatering Pumps chamber arrangement


Balancing Reservoirs / tanksBalancing Reservoirs / tanks

Delivery CisternDelivery Cistern

Gravity Canal with CM & CD worksGravity Canal with CM & CD works


II) Electro – MechanicalII) Electro – Mechanical

Pumps & MotorsPumps & Motors Control PanelsControl Panels SCADASCADA TransformersTransformers Dewatering PumpsDewatering Pumps EOT crane for Pumps HOPDV / NRV / EOPDV etc within pump house


III) Hydro – MechanicalIII) Hydro – Mechanical

Pressure mains with design diameter and thickness Pressure mains with design diameter and thickness Surge Protection Devices based on the surge analysisSurge Protection Devices based on the surge analysis Valves such as air valves at regular intervalsValves such as air valves at regular intervals Stop logs & Trash racks Stop logs & Trash racks Manifold to connect for smooth distribution of Manifold to connect for smooth distribution of

discharge from delivery pipes of pumps into pressure discharge from delivery pipes of pumps into pressure mains mains

Semi Portal crane for Stop logs & Trash racks


Pump House for Wet Pit / VT Pump in River Pump House for Wet Pit / VT Pump in River


Planning & Design Of LI Schemes

I. I. Hydrology

II. Alignment

III. Hydraulic Particulars

IV. Pumps – type, number & capacity

V. Intake Sump / Surge pool / Fore bay

VI. Design of Pump House

VII. Pressure mains / Water conductor system


Planning & Design Of LI Schemes

VIII. Surge protection system

IX. Delivery Cistern / Out fall structure

X. SCADA – Supervisory ( Sequential )

Control And Data Acquisition

XI. Canal networking system


HYDROLOGY

Design Discharge shall be computed for :Crop Water requirementSeepage & Evaporation LossesDrinking Water requirementOperation period of Pumps ( Preferably 24 hrs )

Low Water Level shall be :Above bed level of sourceAbove MDDL of reservoirs at river intakeFor pump houses far away from source, conveyance losses shall be deducted from LWL / MDDL of source


SRIPADA YELLAMPALLI RERSERVOIR


AMRP – SURGE POOL

Size : 20mX50mX62m


A.M.R.P. - DELIVERY MAINS

655m Long 2500 Dia Pipes of 14 & 16thick


ALI SAGAR L.I.S PUMP HOUSE 3


HANDRI NEVA SUJALA SRAVANTI L.I.S.


ALI SAGAR L.I.S. DELIVERY CISTERN STAGE - I


TADIPUDI LIS


RAJIV BHIMA L.I.S


J.C.R. G.L.I.S.


GUTPAH L.I.S


Fixing of LWLFixing of LWL

Whenever pumping is proposed from a reservoir, Whenever pumping is proposed from a reservoir,

LWL shall be above the MDDL, otherwise the LWL shall be above the MDDL, otherwise the

following draw backs will be there :following draw backs will be there :

Encroachment into dead storageEncroachment into dead storage

Has impact on already committed ayacut of projectHas impact on already committed ayacut of project

Reservoir takes extra time to get filled up and Reservoir takes extra time to get filled up and

cannot give water to committed ayacut in time, cannot give water to committed ayacut in time,

during next seasonduring next season

Increases pumping head, pump capacity and also Increases pumping head, pump capacity and also

project costproject cost


ALIGNMENT

The alignment finalisation consists of :

- Fixing of Pump house location in the foreshore

of river / reservoir

- Approach and gravity canal lengths

- Length of Pressure mains

- Utilization of tanks en route the alignment

- Number of Lifts / Pump houses


Fixing of Pump House LocationPump house location shall be located such a way that it needs :

Smaller length of approach canal

Smaller length of approach bridge from TBL Approach Canal and Gravity CanalApproach canal capacity should be 50% more than required for river intake :

Off take point of approach shall not be silt accumulation region as it is the gate way of the LIS

Greater length of gravity canals has to be explored to achieve economy by reducing pipe length.


Length of Pressure mains

Shorter length of Pressure main shall be provided

since length has bearing on cost of the scheme.

If length increases:

•- Pumping head increases there by pump

capacity

•- Pipe thickness increases

•- Surge protection devices required more

•- Capital cost increases


Utilization of Tanks / Balancing Reservoirs ( BR )

Balancing Reservoirs make the scheme economical as well as efficient as : Design discharge of pumps

can be reduced which reduces pump capacity, pipe dia and canal sizes

Flood waters can be stored in the balancing reservoirs for future needs

Better Synchronization of lifts is possible in multiple stages of lifts


Number of Lifts / Pump housesNumber of lifts / pump houses depend on : Length of the canal Total Pumping head required Presence of command en route the canal Capacity and type of proposed pumps

No. Disch LWL Platform Delivery Intake/Gravity Length Pipe Length

Lift ILift IILift III

Fig 1 SCHEMATIC DIAGRAM SHOWING 3 - LIFTS OF CHAGALNADU L.I. SCHEME

CBL +15.00M

+37.00

- 3.0LIFT I

+2.30+2.75

RIV

ER

+18.00AVG.G.L

LWL + 13.50+8.00

+6.50

+18.45

+14.00

+18.80

+22.80

M.F.L +20.80

BED LEVEL OF JACKWELL

-1.00

C.C M20GRADE

Pressure mains

+22.80

Avg. G.L

+8.00

+16.00M

Delivery IBank

FSL +18.00M

LWL + 16.715+16.00M CBL +15.00M

Delivery I

FSL +18.00M

LIFT II

+ 22.60

6.56 cumecs6.56 cumecs6.06 cumecs

+ 23.60m+ 41.30m+ 60.60m

20.00m4540.0m4080.0m

+ 22.80m+ 22.60m+ 46.25m

+ 13.00m+ 16.715m+ 38.795m

200.0m1350.0m525.0m

LWL + 38.795FSL +40.00+41.30CBL +38.53

Delivery II

LIFT III

+ 46.25Delivery III

+60.60


HYDRAULIC PARTICULARSAfter finalising the pump house location, the length of canal,

pressure mains are to be calculated.

HPs of the scheme w.r.t. LWL and FRL of proposed sumps

HPs of approach & gravity canals and pipe alignment.

Total quantity of water required to be lifted in specified

period

Discharge at pump house considering water requirement at

various locations en route the alignment.

If period of water availability in source is less than operation

period of scheme, balancing reservoir ought to be provided.


PUMPS Pumps act as heart of LI Scheme and play important role in

the performance as well as efficiency of the LIS.

Designer should have a comprehensive knowledge on

availability of various types of pumps and their applications

along with their limitations.

Any wrong judgment in selection of pumps may lead to

procurement of unsuitable pumps and the scheme may face

threat of repairs & maintenance along with non-functionality

to the design requirement of the scheme.

Higher capacity increases unnecessarily the capital cost and

power consumption. On the other hand lower capacity will

not deliver design discharge.


Number of Pumps

Number of pumps and pump houses to be proposed

depend on :

Capacity of Pumps

Suction Lift and

Type of pumps


Design Discharge

Total quantity of water to be pumped in the Total quantity of water to be pumped in the specified period shall be computed based on specified period shall be computed based on

1.1. Crop water requirement Crop water requirement 2.2. Seepage & Evaporation Losses Seepage & Evaporation Losses 3.3. Drinking water requirementDrinking water requirement 4.4. Pumping hoursPumping hours


Determination Of Pumping Head

Total pumping head should be arrived with care since Total pumping head should be arrived with care since any any wrong calculation has a bearing on the wrong calculation has a bearing on the performance of the pump.performance of the pump.

Excess head may lead to un-necessary increase in Excess head may lead to un-necessary increase in pump capacity and power consumption pump capacity and power consumption

Lesser head may lead to non-functionality of the pumps Lesser head may lead to non-functionality of the pumps to design efficiency as well as design discharge.to design efficiency as well as design discharge.


Total Pumping Head is obtained on summation Total Pumping Head is obtained on summation ofof

Static head between LWL & delivery level Frictional losses Losses due to exit, entry and bends System resistance losses due to the combined /

operation of pumps and pressure mains


Capacity of Pumps

Capacity of pump can be calculated using formula : Pump capacity in KW = 9.81 Q H / η Pump capacity in HP = 9.81 Q H / 0.746 η( Motor capacity may be 10% to 20% more than pump capacity ) Where Q = Discharge in cumecs

H = Hst + Hf + Hb = Total pumping head in mη = Efficiency of pump


The frictional losses in the pressure main is to be calculated using Hazen-William’s formula :

Hf = L ( 1.778 V / C R0.63 )1.852 Where V = Velocity in pipe ( m/s )

R = Hydraulic Radius (m) = D/4 C = Hazen William’s Coefficient = 130 for PSC pipes

= 130 + 0.17 d ( dia in inches ) for MS pipes with lining

It is desirable to limit the C value to 130 only.


Types of Pumps

Horizontal Centrifugal Pumps - Applicable for medium heads and discharges and has the limitation of suction lift and hence may be better suited for LIS on canals or tanks with total suction lift less than 6.0m.

Vertical Turbine Pumps - Applicable for schemes with high heads and discharges. Best suited for the schemes where the suction lift is more than 6.0m and more applicable to schemes on rivers.

Concrete / Metallic Volute Pumps -Applicable for schemes with high heads and huge discharges.

Francis turbine Pumps - Applicable for very high heads and very huge discharges.


Factors for deciding type Of PumpsFactors for deciding type Of Pumps

Type of pumps to be adopted is governed by :Type of pumps to be adopted is governed by : Hydraulic requirement such as discharge and Hydraulic requirement such as discharge and

total pumping headtotal pumping head Pump house locationPump house location Suction liftSuction lift Total pumping headTotal pumping head Pump capacityPump capacity Manufacturing limitations of respective pumps Manufacturing limitations of respective pumps


Horizontal Centrifugal PumpsHorizontal Centrifugal Pumps

Used for medium head & discharges. Used for medium head & discharges. Useful to lifting from canals or for smaller Useful to lifting from canals or for smaller

discharges.discharges. Have limitation of suction lift. Have limitation of suction lift. Usually the suction lift is not allowed Usually the suction lift is not allowed

more than 6.0 – 6.5m more than 6.0 – 6.5m


Horizontal Centrifugal Pumps

-When Suction lift is less than 6.0m-Applicable for lifting from Canals- For low heads and low discharges


Arrangement of Horizontal Centrifugal Pump House


Vertical Turbine PumpsVertical Turbine Pumps

When the site conditions are not When the site conditions are not favourable for horizontal centrifugal favourable for horizontal centrifugal pumps, i.e., whenever the suction lift is pumps, i.e., whenever the suction lift is more than 6.0m, VT pumps are more more than 6.0m, VT pumps are more suitable. suitable.

Vertical Turbine pumps are most widely Vertical Turbine pumps are most widely used in the LI schemes due to their used in the LI schemes due to their capacity to lift wide ranges of discharges capacity to lift wide ranges of discharges & heads.& heads.


Limitations Of VT Pumps :

They are not preferred for discharges more than 10 cumecs and total head more than 75.0m.

If the head fluctuation is more than 20m, they may not function efficiently with shaft length more than 20.0m, they develop operational & vibration problems.


Arrangement of Vertical Turbine Pump House

CRANE GIRDER

1450 Ø DELIVERY PIPE

LWL + 319.50TOP OF GUIDE BUND + 320.00

+ 317.75

+ 314.50

REFLUX VALVE

SLUICE VALVE

8

1

STOPLOG GROOVE

TRASHRACK GROOVE

BREAST WALL

35 t E.O.T. CRANE

+ 341.25

+ 343.75

FILLING

BEAM B3

BEAM B2 BEAM B1

BEAM B4

BEAM B5

BEAM B6 BEAM B7

W

V

V

250 Th IN M 10 GRADE WITH MSA 40

MANUALLY OPERATED CRANE ( 5 t CAPACITY )

+ 339.25

+ 315.00+ 313.75

+ 339.00

+ 349.00

+ 319.75

+ 324.50

+ 329.25

+ 334.00

+ 346.00

+ 340.50

4000 Ø MANIFOLD

CBL + 317.50

2500

5000 3500 2500 1500

CROSS SECTIONAL ELEVATION OF JACKWELL CUM PUMP HOUSE ( SECTION 1 - 1 )

V

V

10000

225 Th BRICK WALL

1

1

ASSUMED ROCK FOUNDATION AT + 319.50

SLAB S1

SLAB S2

COLUMN C1

500 THICK R.C.C.

1250THICK RCC RAFT

1250 THICK R.C.C. STEINING WALL

-When Suction lift is more than 6.0m-Applicable for lifting from reservoirs & rivers-For medium heads and medium discharges


VERTICAL TURBINE PUMPS


Concrete Volute Pumps These pumps are almost similar to dry pit pumps These pumps are almost similar to dry pit pumps

arrangementarrangement Cannot be used for unlimited capacities / huge Cannot be used for unlimited capacities / huge

magnitudes though can be used for capacities more than magnitudes though can be used for capacities more than Vertical turbine pumps.Vertical turbine pumps.

Technically, they are end suction pumps erected vertically Technically, they are end suction pumps erected vertically with extended / lengthy shaft in between pump and motor.with extended / lengthy shaft in between pump and motor.

Useful for discharge of each pump upto 10 cumecs and Useful for discharge of each pump upto 10 cumecs and head is less than 150mhead is less than 150m

Volute Pumps with head more than 50.0m need metallic Volute Pumps with head more than 50.0m need metallic lining of volute and may be imported.lining of volute and may be imported.

Discharge control is not possible and need more power Discharge control is not possible and need more power even for reduced discharge ( unlike Francis turbine )even for reduced discharge ( unlike Francis turbine )


CONCRETE VOLUTE PUMPSApplicable for l i f t ing from reservoirs & rivers

For high heads and high dischargesPump rating may be upto 15.0 MW

When fluctuation of water levels is > 25.0m


Dry Pit / Francis Turbine Pumps These pumps are also termed as reversible turbines These pumps are also termed as reversible turbines

since they operate in reverse direction for pumping.since they operate in reverse direction for pumping. Useful and economical for very high heads Useful and economical for very high heads

( >100m ) and high discharges (>10 cumecs). ( >100m ) and high discharges (>10 cumecs). Considerable economy can be achieved by reduction in Considerable economy can be achieved by reduction in

number of pumps, lifts.number of pumps, lifts.

O & M problems are minimum in O & M problems are minimum in Dry pit pumps as the components areDry pit pumps as the components are

in dry condition. in dry condition.


These pumps are going to play vital role in the interlinking of rivers where it is required to lift huge quantity of water to very high heads.

Lift requirement of head less than 100m and discharge less than 10 cumecs, adoption ofthese pumps are un-economical for following reasons Require very big pump house Need surge pool (not required for other pumps ) Huge concreting Heavy gantry

These pumps were installed in AMRP to lift 68 cumecs to a head of 102m to irrigate 2.2 lakh acres using 4 pumps of 19 MW(each)


INTAKE SUMP / FOREBAY The objective of sump and approaches is to provide

storage and good / smooth flow conditions in sump. If the design is with poor geometric features, undesirable

flow conditions develop in the sump which reduces the pump efficiency.

To develop uniform, steady and non-turbulent flow conditions in the sump, it is recommended to allow max velocity of 1.2 m/s at the entry of forebay and 0.30 m/s near the pumps.

Forebay may be tapered with limiting enlargement angle in plan to 20 degrees and bed slope in elevation 10 degrees.

However, it is desirable to provide 15 degrees in plan and bed slope of 8 degrees.

08.08.2011 NAC, HYDERABAD 58 1212

0.5D

2D

0. 5D

L = 4 TO 10D

D

0.25DV < 0.3 m/sec

D

0.5D

B ell mouth

L .W.L

S = 1.5D(mini)

dSINGLE P UMP SUMP

0. 75D TO 1D

T

W = 6D + 2T

2/ 3WLe vel floor

D

v < 0. 3m/ secv > 1. 2m/sec

> 20

Down slope> 10°

d

S = 1.5D(mini) 0.5D

D

L .W.L

Bell mouth

0.75 to 1D

>10°

2/3 W

MULTIPLE PUMPS SUMP

C.B.L

Good features of sump design: Whered = Diameter of column assemblyD = Diameter of bowl assemblywhich is usually in the range 1.5dto 1.8dT = Thickness of baffle wall / pierGood features:

• Bell mouth near to sump floor; c = 0.5D.• Flat sump floor.• Width about 2D.• Submergence below LWL not less than 1.5D(mini).• Length of approach shall not be less than 4D and preferably up to 10D in case of single pump sump and 2/3W in case of multiple pumps sump.• Distance of rear wall from pump X = 0.25D in case of single pump sump and 0.75D to 1.0D in case of multiple pumps sump.• In any case, mean velocity of flow approaching bell mouth should be 0.3m/sec or less.


Forebay sides on water side shall be vertical

( atleast upto LWL ) as slopes will cause off

sets at pump house generating vortices.

Jump formation shall be strictly avoided near

pumps as it creates turbulence.

Proposals of intake sump for major LIS shall

be ascertained by physical sump model studies

for fine tuning of the flow conditions and

satisfied, before commencement of execution.

Intake sumps in the river foreshore shall be

provided with controlling arrangement at

entry of forebay also to facilitate maintenance

of the sump, in addition to gates provision in

front of the pumps.


ALI SAGAR- Intake Sump & Pump House


DESIGN OF PUMP HOUSE

Wet Pit Pump House- The pump will be submerged in water. Substructure will be always in water

Ex : Pump house with Vertical turbine pumps.

Dry Pit Pump House- It is also called as reversible turbine. Access can be there to all the components including pumps. Substructure will be without water and in dry condition. Hence maintenance is very easy.

Ex : Francis turbines and Volute Pumps


I) Pump House / Pumping StationI) Pump House / Pumping Station Approach CanalApproach Canal Intake / Sump / Forebay / Surge poolIntake / Sump / Forebay / Surge pool Sub structure / sumpSub structure / sump Super structure to accommodate Pumps & Super structure to accommodate Pumps &

MotorsMotors Service / maintenance bayService / maintenance bay Control panel roomControl panel room Gantry for Pumps, Stop logs & Trash racksGantry for Pumps, Stop logs & Trash racks


Hydraulic Provisions Hydraulic Provisions of VT Pump House Distance between the pump rear wall and the trash rack Distance between the pump rear wall and the trash rack

shall be between 4D to 8D depending upon the percentage shall be between 4D to 8D depending upon the percentage of obstruction through trash rack (Generally it may be 6D) of obstruction through trash rack (Generally it may be 6D)

Breast wall (upto LWL from top) in front of pumps Breast wall (upto LWL from top) in front of pumps improves hydraulic condition and also reduces height of improves hydraulic condition and also reduces height of stoplog & trash racks.stoplog & trash racks.

Pumps shall be located 4.5m (app) away from stiening Pumps shall be located 4.5m (app) away from stiening wall to accommodate non-return valve & butterfly valvewall to accommodate non-return valve & butterfly valve

1m thick RCC piers are generally provided in between 1m thick RCC piers are generally provided in between pumps to support pumps and to accommodate stop logs & pumps to support pumps and to accommodate stop logs & trash rack grooves and also to act as baffle walls in trash rack grooves and also to act as baffle walls in between pumps to improve hydraulic conditions.between pumps to improve hydraulic conditions.

Dewatering / Silt removal pit is to be provided adjacent to Dewatering / Silt removal pit is to be provided adjacent to the stop log groove within the sump for maintenance the stop log groove within the sump for maintenance purposepurpose


Design of Stop logs :

Stop logs for VT pump house may be designed for LWL operation

and may be procured for single vent only.

Stop logs for dry pit pump houses shall be designed for FRL

condition to facilitate maintenance of pumps above LWL also.

Motor Floor Level : In absence of Balancing Reservoir, multiple

lifts with lengthy approach canal need proper drainage system /

escape regulator to avoid inundation of drawing pumping station

during power failure. The motor floor level shall be kept above the

possible inundation level.

Design of Pump House Raft : Raft of dry pit Pump house shall be

designed for uplift pressure of water on fore bay side.


PRESSURE MAINS

Pressure mains function as nerves of LI scheme and they consume lion’s share of the project cost, if pipe lengths are longer.

Length of pipe has direct bearing on pumping head thereby on pump capacity & Surge protection system.

MS pipes and PSC pipes are under more usage in LIS. It is desirable to limit the velocity 2m/sec in MS pipes

and 1.5 m/sec in PSC pipes. Velocity more than 2.0 m/s in MS pipes may be

considered for the schemes with shorter length of pipeline duly examining the impact on pump capacity.


MS pipe thickness is to be calculated based on :

Stress Criteria:- Compressive Stress & Tensile Stress

Buckling

Deflection Criteria

Minimum thickness of MS pipe shall be as per

recommendations given in IS : 1916.

As a thumb rule, D/t ratio may be provided 185 for pipes

with shorter length & medium heads and D/t ratio between

185 to 150 for high heads with lengthy pipes, subject to

satisfying the surge conditions.


Pipe Testing for Thickness

Radiography test

UV Test

Hydraulic Test

Hydraulic test may be 1.5 times design pressure as per codal

provisions and 1.25 times as per AWWA. For shorter length and

smaller heads, the hydraulic test may not be governing for pipe

thickness, however for lengthy pipes with high heads, it has

bearing on the scheme cost and hence shall be careful in adopting.

In GLIS, for 130 KM length with 135m head 14mm and 16mm

are provided for 2500 mm dia & 3000 mm dia respectively. If it is

TWICE, the pipe cost could be 25% more than actual cost.


SURGE PROTECTION SYSTEM Whenever power failure occurs, rapid changes in

velocity and any change in pressure results in the pipe line causing surge pressure.

Power failure leads to movement of upsurge and down surge waves along the rising main and the waves travel with high speed developing low & high pressures

all along the pipe line. Down Surge - Related to pressure drop or minimum

pressure. Pressure drop immediately after power failure at peak locations causes negative pressure, which may even go down to vapour pressure.

Up Surge - Related to pressure rise or maximum pressure. When separated water column rejoins, sudden pressure rise occurs


Surge analysis is a very complicated phenomenon and needs thorough analysis of the pipe line profile w.r.t surge heads to assess type and number of surge protection devices to be provided at appropriate locations.

Due attention shall be given to the surge analysis of pipe lines for schemes with high heads and lengthy pipes.

The surge generated can be controlled by providing combination of surge protection devices at various locations.


Surge Protection Devices & Their Function Air Vessel - Controls upsurge and down

surge One way Surge tank - Controls down surge

directly and upsurge indirectly

Two way Surge tank- Controls both down surge and upsurge

ZVV & Surge relief valve - Controls upsurge Air valves / Air cushion Valves - Controls down

surge directly and upsurge indirectly Stand pipe - Controls down surge


Zero Velocity Valve


Elevated OST


ONE WAY / TWO WAY SURGE TANKS


Water Hammer ConditionsSurge effect depends on topography / terrain, velocity and pipe

length and is predominant when frictional losses are more.

High Points in the pumping main alignment

Possibility of Water column separation in the main due to sudden power failure

Pipe line gradient is steeper than 1 : 20

Ratio of frictional loss to working head is less than 0.7

Presence of Check valve with slow closing arrangement

Velocity of normal flow exceed 1.0 m/s


DELIVERY CISTERN

Delivery cistern is to be provided to dissipate the

energy of water falling freely from the pressure mains

and delivers into the canals.

Cistern shall be designed as vertical drop.

To have better energy dissipating arrangement, the bed

level of the cistern should always be kept below

the bed level of the leading canal.


Delivery Cistern


SCADA ( Supervisory Control And Data Acquisition )LIS with Multiple pumping

stations needs proper monitoring and vigilance for better synchronization, for which SCADA installation is mandatory.

SCADA collects and detects data such as :Non-functioning of pumps in any of the pumping stationsNon performance of any of the surge protection devices such as air vessels / One way surge tanks ( OWST ) etc,.


SCADA Records data during operation of the scheme

Monitors inflow and outflow discharges of pumps

SCADA will be controlled at one station monitoring total alignment. Origin of failure of any component of the system enroute the alignment can be detected using SCADA, with the help of which operation of other pumping stations can be controlled.


IMPORTANT ASPECTS IN DESIGN OF L.I.S.Influence of Velocity in Pressure main With increase in velocity of pipe, frictional loss increases

thereby increasing pump capacity along with pipe thickness due to pumping head as well as surge head

For every 0.50 m/s rise in Velocity of pipe, frictional loss rises by 75% to 100% with reduction of dia by 11% to 13% only.

Smaller dia is economical during initial stage of construction but power consumption will be high . Higher dia needs less power but with high initial cost.

Hence, it is desirable to allow higher velocities in shorter length of pipes and lower velocities in lengthy pipes ( particularly when the length of pipe is in KM ) owing to the recurring power consumption annually.


Advantages of Minimum number of Rows More number of pipes with smaller dia leads to

more frictional losses as well as enhanced pumping heads /

pumping capacities and more quantity of steel.

More pipes with smaller dia causes more frictional losses

and initial cost as well as recurring power cost over lesser

no. of pipes with bigger dia with same velocity.

Further, more number of rows need more land acquisition

and CM & CD works.

Hence, it is desirable to provide bigger dia with less

number of rows of pipes, particularly for the schemes with

lengthy pressure mains.


Precautions to be taken in Laying & Design Of Pressure mains

Pipe lines in Soft Soils Care shall be taken in designing and laying of pipes in soft

soils / BC soils etc., Either pipe shall be designed for the soil condition or the refilling has to be done with selected soils as the soil modulus is also one of the parameter in design of pipe thickness for buried condition.

Since soil modulus is also one of the major property influencing pipe thickness, it is desirable to have refilled soil gets compacted to achieve minimum 90% Proctor’s density.

Water logged areas causes settlement of pipes or uplifting of pipes, which shall be designed accordingly.

Hence the above field conditions shall be conveyed to the designer wherever the pipes pass through such areas.


Clearance between Pipes

Clear distance between bigger dia pipes with more than two rows may be min of 5.0m for inspection :When multiple number of rows of pipes are laid and some of the pipes are only in operation, then empty pipes may create instability among the combined trench or when pipes are closely placed.Scour sluices / washouts with projections to flush out the water in pipes get overlapped when pipes are closely placed.It is desirable to have independent thrust blocks to avoid problems during O & M in the vicinity.


If adequate clearance is not provided in water logged areas,

whenever any one of the pipe is empty, imbalance condition

develops which results in settlement or uplifting of pipe.

Handling of heavy / bigger dia pipes need crane for erection

& maintenance which needs 5.0 m ( min ) clearance in

between pipes

Whenever pipe is to be laid adjacent to the existing pipe in

operation, new pipe needs excavation and disturbs existing

pipe trench. Thus weakening the degree of compaction made

to already existing one and resulting imbalance of earth

pressure on existing pipe. If sufficient gap is provided, the

effect can be minimized.


Connection of Pump delivery pipe and Pressure mains

When multiple number of rows of delivery pipes are required to

be connected to a pressure main, a manifold is required. In which

case, the design discharge may be increased by 2.5% for each pump to

account for system resistance losses in manifold.

Types of Manifolds

WYE type – May be useful when one or two delivery pipes need to be

connected to a single pressure main

Cylindrical – When rows of pressure mains is less than no. of pumps

Whenever stand by pump is provided, cylindrical manifold may be

mandatory ( twice the dia but not less than equivalent dia of pressure

mains) as rotation of stand by pump in wye junction is not possible to

satisfy equal discharge in pressure mains.


CONCLUSIONS L.I. schemes are going to play major role in coming days and

due attention shall be given to the planning and design of LIS for better performance and efficiency of schemes.

Alignment shall be so chosen comprising shorter length of approach channel and shorter length of pressure mains. As far as possible, greater length of gravity canal shall be provided for economy in LIS.

Pumps function as heart of LIS and hence attention shall be given in fixing the duty point of the pump. For optimization of the scheme, duty point shall be with respect to level above LWL.

Pumping discharge shall be designed for mean average of crop water requirement wherever intermediate balancing reservoirs are present with pumping stations.


Importance shall be given in design of sump dimensions and arrangement to avoid undesirable flow condition. Physical model studies shall be conducted for LIS and shall be mandatory for river intake lifts.

As the pressure mains act as nerves of LIS, care shall be taken for pipes to be laid in BC soils, water logged area and at crossing of vagus/drains.

Low velocity in pipes may be economical for the schemes with lengthy pressure mains, however higher velocity in pipes may be permitted for schemes with shorter length.

Larger dia with less number of rows may be economical with respect to installation cost as well as running cost.

Adequate clearance shall be maintained between pipes for stability as well as maintenance purpose.

Due attention shall be given to surge parameters which are vital aspects for proper functioning of the pipe line.

LI Scheme comprising multiple pump houses shall be provided with SCADA for observing & monitoring entire system.


AYACUT DETAILS OF L.I.SCHEMES

PUSHKARA L.I.S. - 1,85,906 Ac TADIPUDI L.I.S. - 68,600 Ac RAJIV SAGAR L.I.S. - 4,00,000 Ac ALISAGAR L.I.S. - 53,793 Ac GUTPAH L.I.S. - 38,793 Ac RAJIV BHIMA L.I.S. - 2,03,000 Ac NETTAMPADU L.I.S - 2,00,000 Ac KALWAKURTHY L.I.S. - 3,40,000 Ac H.N.S.S. L.I.S. - 6,21,000 Ac


POWER GENERATION IN A.P.

1 THERMAL 2973 MW

2 HYDRO 3586 MW

3 GAS 999 MW

3 BIO MASS 312 MW

4 WIND 98 MW

5 MINI HYDEL 91 MW

6 SHARE FROM CENTRAL SECTOR 2465 MW

7 OTHERS 182 MW

10706 MW


POWER PLANTS NEARING COMPLETION

1 THERMAL 810 MW

2 HYDRO 474 MW

1284 MW

POWER PLANTS PROPOSED

1 THERMAL 7000 MW

2 OTHERS 2882 MW

9882 MW


Thank You


AMRP LIFT SCHEME(SLBC)


SLBC LIFT SCHEME

Aim : 1) To provide irrigation (ID) to 2.20 lakh acres

2) To provide drinking water to 516 villages


SLBC LIFT SCHEME

COMPONENTS APPROACH CHANNEL APPROACH TUNNEL SURGE POOL PUMP HOUSE DELIVERYMAINS CISTERN LINK CANAL AKKAMPALLY BALANCING RESEVOIR MAIN CANAL


APPROACH CHANNELAPPROACH CHANNEL

Length : 3.325kmBed width : 15mFSD : 4mDischarge: 3000 cusec

APPROACH TUNNEL

Length : 1.475kmShape : CircularDiameter : 6mLining : 300mm ThickBed Fall : 1 IN 288

INTAKE STRUCTURE


SURGEPOOL

Size : 20mX50mX62mBottom Level : +138.00mDraft Tube Gates : 2.60mX5.00mWeight of each gate : 8.07MT


PUMP HOUSE

Size : 16mX60mX65mBottom Level : +135.00mPumps : 4No.s of 18MW eachCapacity of each pump: 600 CusecHP of each Pump : 25000


SLBC LIFT SCHEME

COMPONENTS APPROACH CHANNEL APPROACH TUNNEL SURGE POOL PUMP HOUSE DELIVERYMAINS CISTERN LINK CANAL AKKAMPALLY BALANCING RESEVOIR MAIN CANAL


DELIVERY MAINS

Size : 2.50m dia CircularLength : 655mNo. of rows : 4No.sSteel : IS 2002 Grade-IIIThickness of Plates : 14mm

& 16mm


Cistern Reservoir Bund

Length of Dam : 2.290kmCapacity : 0.28TMCFRL : +247.00mTBL : +249.00m


LINK CANAL

Length of Canal : 9.260 kmDischarge : 2400 CusecBed Width : 2.00 mFSD : 3.00 mBed fall : 1 in 7000


A.M.R.P. Main Canal From Akkampally Balancing Reservoir

Surplus EscapeMain Canal Regulator


H.Ps of Main CanalAt Km 25.000 (Common point)

Discharge: 65.258 Cumec

Bed Width: 19.10 m FSD : 3.10 m CBL @ starting: +230.100 m


SALIENT FEATURES

MDDL : +155.45m Max. Elevation to be pumped :249.00m Maximum Static Head : 96m Minimum Static Head :69m Cost of the Scheme :Rs.1026 Crore Cost of Head works up to Cistern intake :Rs.300 Crore


PUMPS

Type of Pump : Vertical shaft single stage Francis Type Runner

Normal speed : 428.60 RPM Rated Discharge : 16.85 Cumec (600 cusec) Guide vane centre l ine : +142.00m Submergence of GV

central l ine below min. water level : 11.00m Allowable frequency : 50.5Hz to 47.50Hz.


DESIGN OF PUMPS

Capacity of Pump = 9.81XQxHX1.25 KW Efficiency

where Q= Discharge in cumec H= Dynamic Head in m

Capacity of Pump = 9.81X16.85x81X1.25 / 0.92 =18191KW or Say 18MW

These pumps function from 69m static head to 96m static headThe discharge varies with reference to variation in head and frequencyGuide vane opening is to be adjusted as per head and frequencyThough pumps are designed for 18MW , the input is about 15 MW only


MOTORS

Type : Vertical shaft AC motor Speed : 428.60 RPM Power : 18 MW – 11 KV Frequency : 50 Hz Pf (leading) :0.95


ENERGY CALCULATION

Energy Required (E)= QxWXH 60X60XEfficiency

where Q= Quantum of water in million cum

W =9.81KN/m3

H= Dynamic Head in m E= Energy in million KWH


ENERGY REQUIREMENT

Energy requirement for the scheme is worked out based on the average levels of Nagarjuna Sagar Reservoir.

The quantum of water to be lifted is 22TMC Energy required for the scheme is 135Million KWH Cost of Energy Charges per annum is Rs.34 Crore

(Rate per unit:Rs.2.36) Maintenance charges including staff : Rs.3.00 Crore per annum Cost of Maintenance & Energy Charges per Acre is Rs.1680


Thank You

080811 planning and design of l.i.s.s

Documents

major irrigation total

minor irrigation

medium irrigation

kharif ayacut

ac tadipudi

ac gutpah

ac alisagar

ac nettampadu