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MHP MHP Components

MICRO HYDRO COMPONENTS ANDSURVEYING ASPECTS

Presented by:Krishna Prasad Devkota

UCS/NMHDA

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Contents of the Presentation

MH Components

Site Survey

Load Survey Flow Measurement

Location & Alignment Fixing

Alignment Survey & Head Measurement

Power Equation

Reporting

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Civil Components

Mechanical Components

Electrical Components(Electro-mechanical Components)

Transmission/Distribution Network

Components of Micro Hydro Project

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N

Forbay

Tailr

ace

Penstock Pipe

Power House

WEIR

Spilw

ay

Canal

River/Khola

Spilw

ay

Anchor Block

Anchor Block

Support PierKholsa

Crossing

HeadraceCanalDe

silting

Basin

Major Civil Components Of MicroHydro Scheme

n3'hnljB't cfof]hgfsf l;len;+/rgfx?

Intake

WeirCanal

CrossingForebay

Anchor Block

Support Piers

Power House

Tailrace

Source

Spill way

Trashrack

Spillway

Civil Components of Micro Hydro

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Weir and Intake

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Desilting Basin

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Canal

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Forebay

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SUPPORT STRUCTURES

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Powerhouse and Tailrace

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400/11000V,15kVA

L.T.L ightningArrestor

R

Y

B

N

Forbay

AnchorBlock

ExpansionJoint

Air VentPipe

SupportPire

AnchorBlock

PenstockPipe

ELC Board

Generator

Turbine

Trasrack

Power House

Electro Mechanical Components Of Micro Hydro Scheme

H.T.LineL.T.Line

T.Plateform

MCCB

H.T.Li ghtningArrestor

Drop-outFuse

Transformer( T1)

GroundL evel

DangerPlate

Penstock pipe

TransmissionLine

Transformer

ELC

Earthing

Generator

Turbine

Electro-Mechanical Components of Micro Hydro

Expansion J oint

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Electro-Mechanical Arrangement

Turbine

Generator

Base Frame

Valve

Expansion J oint

Pressure Gauge

Direct Coupling

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Pulley & Belt

Turbine Genrator

ELC=

Balast Tank

Electro-Mechanical Arrangement

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IGC/ELC/Governor

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Transmission/Distribution Network

Powerhouse

Transmission

Line

DistributionLine

Service Line

House wiring

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Transmission/Distribution

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Site Survey

To gather the detailed information

and measurement of the site forthe suitability of the installation ofa micro hydro plant.

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Major Tasks of site survey

Power demand (Load Survey); Flow measurement;

Head measurement; Optimum power output (Tentative);

Water users; High flood level Social aspects

(Interest/motivation/capability/conflict of the community)

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Major Tasks of site survey (Contd...)

Location of the civil structures(Alignment, Geological Aspect & Space Availability)

Transmission/distribution Length(with household distribution);

Protection works;

Environmental aspects;

Economical aspects;

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Demand survey

This survey is mainly the preparation ofpotential consumers list with their powerdemand.

Count the number of households, shops,

lodges, offices, temples, schools,industries etc.

Calculate the power needed for each

consumer (in terms of the numbers of bulbs or tube lights,radio, TV, fans and other appliances).

Calculate total power demand

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Flow Measurement

To find the available discharge in

the source (river/stream) forpower generation

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Bucket method

Conductivity method (Salt dilution method)

Weir method

Current meter method

Float Method

Ultrasonic method

Flow Measurement Method

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Applicability

Bucket method : < 30 lps Conductivity meter: 30 lps to 2000 lps Weir Method:

Triangular Smaller flowRectangular- Larger flow

Current meter: > 2000 lps

Float method: Rough method (only for estimate) Ultrasonic method: for discharge in

penstock pipe/Canal

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Flow Estimation

Common Methods used in Nepal:

MIP method

WECS/DHM method

To estimate the available discharge for thepower generation throughout the year.

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Flow estimation

MIP method for catchment area less than 100km2

For catchment area larger than 100 km2 alongwith the MIP method, WECS/DHM method could

be used Lower values derived from the above two

methods should be adopted

11 month exceedance flow should be comparedwith measured flow of detailed feasibility study

M IP m e thod is m os tly adop ted in N epa l

d ( )

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Developed by M. Mac Donald (consulting firm) in 1990. Country divided into 7 hydrological regions. Based on wading measurements by Department of

Hydrology and Meteorology, non-dimensional regionalhydrographs were developed for each region. The

month of April was used for non-dimensionalizing. Coefficients for each month for each region have been

developed

Mean monthly flows

Low flow measurement

MIP region number

Measurement date

OUTPUTINPUT

MHP

Medium Irrigation Project (MIP)Method

http://www.gtz.de/nepal/projects/shpp.htmlmailto:shp@gtz.org.npmailto:shp@gtz.org.nphttp://www.gtz.de/nepal/projects/shpp.html

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MIP MethodMonth Non dimensional

flow or Region 3

Measured flow

(l/s)

Factor Estimated

mean monthlyflows (m3/s)

January 2.71

Factor = 600/1e.g.

Jan flow =600x2.71 =1626 l/s

1.626

February 1.88 1,128

March 1.38 0.828

April 1.00 600 (15 April) 0.600

May 1.88 1.128

June 3.13 1.878

July 13.54 8.124

August 25.00 15.000

September 20.83 12.498

October 10.42 6.252

November 5.00 3.000

December 3.75 2.250

Annual Avg. 4.526

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Discharge measurement between November &May (dry season)

No rain during the past 3 days from the day offlow measurement

flow (Qd) at river for 11 months excedence.

Consider seepage (5-10%) + environmentalflows (10-15%).

Thus, need to use at most 85% of the 11months exceedance flow.

+- 10% tolerance on Qd at commissioning.

Nepalese Guidelines & Standardsfor MHP Hydrology

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Location & Alignment Fixing

While selecting the location for the MH componentsfollowing considerations have to be made.

Weir and Intake

Possible to divert the flow either naturally or by constructinga simple and low height weir

Headrace Canal

Safe from high flood, landslip, tension cracks, falling rocksetc.

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Settling/desilting Basins

Close to the intake & possible to flush thesediments safely

Forebay

Stable, safe and suitable for penstock route.

Spillways

At forebay, settling basin and at canal (as per necessity)

Location & Alignment Fixing (Contd)

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Location & Alignment Fixing (Contd)

Penstock alignment

Stable, safe, straight as possible with

minimum number of bends and steeperterrain (30 -45)

Powerhouse

adequate space, safe from floods & safeto discharge the tail water back into thestream.

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Alignment Survey & Head Measurement

Common Methods:

Abney Level

Auto Level Theodolite

Total Station

To find the topographical feature and leveldifference between the Intake, forebay andpowerhouse.

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Necessary precautions need to be

made during the survey & projectimplementation period in order toreduce the environmental impacts.

Environmental Consideration

PowerOutputCalculation

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CIVIL COMPONENTS

Head (m)

Power Output Calculation

Village

Discharge (l/s)

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Power Equation

P = * g*Q*H*

Where,

P = Power (Watt)

= Density of water (kg/m3)

g = Acceleration due to gravity (m/sec2)

Q = Discharge (l/sec)H = Head (meter)

= Overall efficiency

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Reporting

Flow Calculation Estimation of Discharge

Design Discharge

Demand Supply Analysis End Use Application

Design & Drawings (sizes of structures/equipment) ;

Cost/financial analysis and

Conclusion and Recommendations.

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Thanks!!!