Balancing Reservoirs 5rq1o

BALANCING RESERVOIR

PRESENTED BYYOGESH KUMAR ENROLL. NO-12512030 M.TECH(AHES)

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Introduction Reservoir and its types. -Service reservoir -Balancing Reservoir Purpose of Balancing Reservoir. Dependency of Balancing Reservoir. How to fix capacity of Balancing Reservoir. Mass Curve Method. Steps required for Mass Curve MethoD Examples for Mass Curve Method. Precautions needed during construction of Balancing Reservoir. Conclusion.

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Reservoir are the most important and expensive elements in any hydro power plant.

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So, one needs to optimize its design (or capacity) carefully , to avoid the future problems.

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Service ReservoirWhen supply from the source is not continuous for all the 24 hours ,then supply from the source is stored in a storage reservoir (whenever it is available) and then supplied to the consumers according to the schedule.

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Balancing ReservoirWhen the supply from the source is continuous for all the 24 hours, then during the lean demand period excess supply from the source is stored in the storage reservoir and during peak demand period , water from this source as well as from the storage reservoir is used to meet the required demand.

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The quantity of water required to be stored in the reservoir for equalising or balancing fluctuating demand against constant supply is known as the balancing reservoir.

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The main purpose is to store the water during off peak hours to supply the same during peak hours and so meeting variable power demand.

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Water Supply Fluctuation - Seasonal fluctuation

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Demand Fluctuation -Seasonal -Daily -Hourly

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Effect of flow fluctuations on system design -Size of balancing reservoirs

 Variable

supply  Variable demand  Analyze historic record to search for worst case conditions  Use same Mass Balance analysis  Include variable demand analysis  It

must be designed for daily or hourly fluctuations.

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Prepare mass inflow curve: - for all 24 hours for typical days.

(maximum , average and minimum) 

Prepare mass curve for demand accordingly.

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Superimpose both curve on the same scale.

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Take the max difference between demand and supply discharge as the capacity of the balancing reservoir

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Available discharge (during lean season) = 5 m^3/s Available Head = 110m Overall Efficiency = 0.8 Demand Required:Hours

(Demand) Load (MW)

0-8

1

8-10

2

10-15

5

15-21

10

21-24

1.2

Hour

(Demand) Load (MW)

Discharge (m3/s)

Discharge (m3)

Cumulative demand discharge (m3)

0-8

1

1.158

33350

33350

8-10

2

2.32

16680

50030

10-15

5

5.80

104400

154430

15-21

10

11.58

250210

404640

21-24

1.2

1.4

15120

419760

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Available discharge (during lean season) i.e.

= 5 m^3/s = 18000m^3/hr

Hour(hr)

Available discharge(m3)

Cumulative available discharge(m3)

Cumulative demand(m3)

0-8

144000

144000

33350

8-10

36000

180000

50030

10-15

90000

270000

154430

15-21

108000

378000

404640

21-24

54000

432000

419760

Determination of reservoir capacity

450000

DISCHARGE VOLUME (m3)

400000

350000

300000

CUMULATIVE DEMAND (m3)

250000

200000

150000

AVAILABLE CUMULATIVE DISCHARGE (m3)

100000

50000

0 0

5

10

15

20

TIME (HOURS)

25

30

Calculation for Reservoir Capacity From the table , during 8-10 hours , Required Demand

= 50030 cubic meter

But, actual available

= 180000 cubic meter

Therefore , required reservoir volume = 180000 - 50030

= 129970 cubic meter

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Inner surface of Balancing Reservoir being in with water should be lined to prevent seepage loss.

Spilling arrangements should be there.

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Some preventive measures in form of excluder and desilting

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chamber are used to avoid the problem of silt .

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Location of balancing reservoir.

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Used in isolated type hydro power plant.

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Capacity(or size) of balancing reservoir depends on : -variable supply and variable demand.

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But economic comparison is also necessary to determine optimum storage capacity by adding cost of reservoirs and pipelines.

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http://www.thewatertreatments.com/water/servicereservoirs-function-type-volume

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http://nptel.iitm.ac.in/courses/Webcourse-contents/IITKANPUR/wasteWater/Lecture%2014.htm

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http://nptel.iitm.ac.in/courses/Webcourse-contents/IITKANPUR/wasteWater/mass%20curve%20method.htm

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o5-reservoirs:http://www.slidefinder.net/r/reservoirs_balancing_supply_d emand/23826463

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Irrigation and water power engineering(B.C.Punmia & P.B.Basi Lal).

THANK YOU