Tanjung Priok GFPPEP

Presentation and discussion, 22 October 2009PT. PLN (Persero) Jasa Enjiniring OfficeJl. KS Tubun I/2 Petamburan, Jakarta

prepared byDepartment of Civil and Environmental Engineering UGMforMHI Heavy Industries, Ltd.Tohosago, Japan

Physical model test to evaluate hydraulic performance of the CW discharge line and seal pit at Tanjung Priok GFPPEP Discharge capacity of the seal pit

▪ no flooding

Water surface profile along the seal pit and outfall▪ no overflow

▪ overflow, turbulence, washout

Energy dissipation at the outfall▪ effective dissipation at the outfall

▪ smooth transition of flow from outfall into the sea

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General layout

inner dia. 3.2 mlength ±60 m

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Model scale is defined at 1:15 considering

Availability of space

Pump capacity

Measuring instruments

A non-distorted model, i.e. similar horizontal and vertical length scale, is selected

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ParametersModel Scale

Notation Calculation Magnitude

Length, Width nL nL 15

Depth nL nL 15

Area nA nL2 225

Volume nV nL3 3,375

Time nT nL1/2 3.87

Velocity nU nL1/2 3.87

Discharge nQ nL5/2 871.42

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Model scale 1:15made of acrylic material

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ParametersPrototype Model

Magnitude Unit Magnitude Unit

Discharge structure

length 24 m 160 cm

width 16 m 106.7 cm

depth 7.9 m 52.7 cm

Discharge

2-pump operation 65,200 m3/h 20.8 ℓ/s

1-pump operation 39,120 m3/h 12.5 ℓ/s

Downstream flow depth

(at the Outfall)

HWL 5.4 m 36 cm

LWL 4.4 m 29.3 cm

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Model scale 1:15

Water Surface ProfileEnergy Dissipation

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Water surface profile computation

Standard step method

One dimensional calculation

Use of HEC-RAS model

Energy dissipation computation

Analytical calculation

Calculation procedure follows the method explained in the USBS Design of Small Dams

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Channel

CW D i scha r ge

None of the XS's are Geo-Referenced ( Geo-Ref user entered XS Geo-Ref interpolated XS Non Geo-Ref user entered XS Non Geo-Ref interpolated XS)

None of the XS's are Geo-Referenced ( Geo-Ref user entered XS Geo-Ref interpolated XS Non Geo-Ref user entered XS Non Geo-Ref interpolated XS)

Head tank (pump pit)

Seal PitDischarge line

Computational Domain

0 2 4 6 8 10 12 14-4

-3

-2

-1

0

1

2

3

HEC RAS Tanjung Priok Plan: CW discharge 1 and 2 pump operation

Station (m)

Ele

vati

on (

m)

Legend

Ground

Bank Sta

0 2 4 6 8 10 12 14-4

-3

-2

-1

0

1

2

3

HEC RAS Tanjung Priok Plan: CW discharge 1 and 2 pump operation

Station (m)

Ele

vati

on (

m)

Legend

Ground

Bank Sta

Examples of cross sectionsJava Sea

Seal Pit

Stilling Basin

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Parameter Magnitude

Discharge 39,120 m3/h (one-pump operation)

65,200 m3/h (two-pump operation)

Sea water level −0.56 m (LWL)

+0.42 m (HWL)

Manning roughness coefficient 0.015

Discharge coefficient of the sill 1.4

Values of parameters applied in the water surface profile computation

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0 10 20 30 40

-6

-4

-2

0

2

4

HEC RAS Tanjung Priok Plan: CW discharge 1 and 2 pump operation

Main Channel Distance (m)

Ele

vation

(m

)

Legend

WS Q 39120 HWL

WS Q 39120 LWL

Ground

ROB

CW Discharge Channel

Stilling Basin Seal Pit

Java Sea

Pipe

Training wall +2.90m

WS +0.62mHWL +0.42m

LWL −0.56m

WS +2.31m

One-pump operation, Q = 39,120 m3/s

0 10 20 30 40

-6

-4

-2

0

2

4

HEC RAS Tanjung Priok Plan: CW discharge 1 and 2 pump operation

Main Channel Distance (m)

Ele

vation

(m

)

Legend

WS Q 65200 HWL

WS Q 65200 LWL

Ground

ROB

CW Discharge Channel

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Stilling Basin Seal Pit

Java Sea

Pipe

Training wall +2.90m

WS +0.86mHWL +0.42m

LWL −0.56m

WS +2.56m

Two-pump operation, Q = 65,200 m3/s

Conclusion

Distance of the maximum water surface at the Seal Pit from the training wall crest is only 30 cm

… but at the Stilling Basin is 2 m

Free-board at the Seal Pit is thus not sufficient

… but at the Stilling Basin is too high

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Recommendation

Increase of training wall along the Seal Pit from +2.90 m to +3.20 m

Lower down the training wall crest at the Stilling Basin from +2.90 m to 1.90 m

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hd

dTW ≥ 2.15dcP

He

He

PY

Lp 0.8dc

LB ≥ LP + 2.55dc

0.8dc

hd

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Parameter SymbolCooling water discharge

39,120 m3/h 65,200 m3/h

Width of sill crest b 16 m 16 m

Unit discharge q 0.6791 m3/s/m 1.1319 m3/s/m

Critical depth dc 0.36 m 0.51 m

Upstream head He 0.62 m 0.87 m

Drop height hd 1.70 m 1.70 m

Seal Pit water surface elevation +2.32 m +2.57 m

Stilling Basin water surface elevation +0.62 m +0.87 m

Stilling Basin water depth dTW 5.62 m 5.87 m

Distance of impinging jet from the sill Lp 3.35 m 4.69 m

Minimum distance of impact block from the

sill

Lp + 0.8dc 3.64 m 5.09 m

Minimum length of Stilling Basin LB ≥ Lp + 2.55dc 4.27 m 5.78 m

Minimum water depth in the Stilling Basin dTW ≥ 2.15 dc 0.78 m 1.09 m

Conclusion The energy dissipation (by free overfall and

Stilling Basin) satisfies the requirement

Recommendation Displacement of the impact block farther away

from the overflow

present position at 3.25 m to 5.10 m

This is not critical since the basin depth is much deeper than the requirement

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Water Surface ProfileEnergy DissipationFlow VelocityFlow Pattern

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Two measurements are done Water surface profile

▪ Electronic device

Flow velocity▪ Imaging technique (PIV)▪ Acoustic Doppler (ADV)

Additional instuments Distance, level

▪ Staff gauge▪ Meter tape

Discharge▪ V-notch

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Imaging technique to measure flow pattern

Acoustic Doppler Velocimeterto measure flow velocity

Capacitance level meterto measure water level (dynamic)

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Staff gauge, meter tapeto measure distance, depth, elevation

Water surface profile Energy dissipation Flow pattern Flow velocity

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Software EXEL

H=421mmH=375mm

H=334.5mm

Data of Water Level At Q h=14.6cm

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Camera

Light SheetSource

Model

Flow Pattern(PIV)

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Instantaneous velocity

(time average) velocity

turbulence intensity and stress

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