Lecture 6
8
Urban Water Supply/Chapter 9 Low Low Lift Lift Intake Conduit Intake Conduit Treatment Treatment High Lift High Lift Conveyance Conveyance Conduit Conduit DISTRIBUTION DISTRIBUTION RESERVOIR RESERVOIR Distributio Distributio Supply Pipe Supply Pipe SEASONAL SEASONAL RESERVOIR RESERVOIR WELL FIELD WELL FIELD
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Transcript of Lecture 6
Storage Reservoirs for Urban Water Supply/Chapter 9
LowLowLiftLift
Intake ConduitIntake Conduit
TreatmentTreatment
High LiftHigh Lift
ConveyanceConveyanceConduitConduit
DISTRIBUTIONDISTRIBUTIONRESERVOIRRESERVOIR
DistributionDistributionSupply PipeSupply Pipe
SEASONALSEASONALRESERVOIRRESERVOIR
WELL FIELDWELL FIELD
Storage Function (stabilize flow)
seasonal reservoir stabilizing varying seasonal supply
distribution reservoir stabilizing a varying demand
OutflowPeak Inflow
0 1 year
Demand curve(Outflow)
Pumping flow(Inflow)
Maximum demand
0 24 hours
Inflow Curve
store store
store
release
release release
I>O STOREO>I RELEASE
How much storage capacity needed? Cumulative Net Storage
S = cum. net storage (L3)Ot = Ot, volume of reservoir outflow (draft) over t
(L3)It = It, volume of reservoir inflow over t (L3)
tttt
OIOIMAXS
Illustration of Sequent-Peak method for Seasonal Storage, Linsley et al. 1989
mttptt
tttt
OIOIS
OIOIS
max
“zero reference”
Reservoir Storage Capacity (cont’d)
Carryover reservoir (Example 9.1) I = varying river flow over critical period (2-3 yrs) O = demands and losses Cannot assume pattern repeats for analysis
Distribution reservoir (Example 9.2) Operating storage only I = steady pump flow O = varying demand from distribution grid over
24 hr critical period Pumping rate = daily demand/pumping period Can assume pattern repeats for analysis
Reservoir Storage Capacity (Graphical and Analytical Method)
Reservoir Storage Capacity (cont’d)
Reservoir Storage Capacity (cont’d)
