Tanjung Priok GFPPEP Presentation and discussion, 22 October 2009 PT. PLN (Persero) Jasa Enjiniring Office Jl. KS Tubun I/2 Petamburan, Jakarta prepared by Department of Civil and Environmental Engineering UGM for MHI 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 2
General layout inner dia. 3.2 m length ±60 m 3
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 4
Parameters Model Scale Notation Calculation Magnitude Length, Width n L n L 15 Depth n L n L 15 Area n A n 2 L 225 Volume n V n 3 L 3,375 Time n T n 1/2 L 3.87 Velocity n U n 1/2 L 3.87 Discharge n Q n 5/2 L 871.42 5
Model scale 1:15 made of acrylic material 6
7
8
Model scale 1:15 Parameters Prototype 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 m 3 /h 20.8 l/s 1-pump operation 39,120 m 3 /h 12.5 l/s Downstream flow depth (at the Outfall) HWL 5.4 m 36 cm LWL 4.4 m 29.3 cm 9
Water Surface Profile Energy Dissipation 10
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 11
Computational Domain Head tank (pump pit) Discharge line Seal Pit CW D i s c ha r ge Channel Examples of cross sections Seal Pit Java Sea HEC RAS Tanjung Priok Plan: CW discharge 1 and 2 pump operation HEC RAS Tanjung Priok Plan: CW discharge 1 and 2 pump operation 3 Legend 3 Legend 2 Ground Bank Sta 2 Ground Bank Sta 1 1 Elevation (m) 0-1 Elevation (m) 0-1 -2 of Geo-Ref the Non XS's user Non interpolated are entered Geo-Referenced usxs interpolated XS entered XS ( XS) -3-4 0 2 4 6 8 10 12 14 Station (m) -2-3 -4 0 2 4 6 8 10 12 14 Station (m) None of Geo-Ref the Non XS's user Non interpolated are entered Geo-Referenced usxs interpolated XS entered XS ( XS) Stilling Basin 12
Values of parameters applied in the water surface profile computation Parameter Discharge Sea water level Magnitude 39,120 m 3 /h (one-pump operation) 65,200 m 3 /h (two-pump operation) 0.56 m (LWL) +0.42 m (HWL) Manning roughness coefficient 0.015 Discharge coefficient of the sill 1.4 13
One-pump operation, Q = 39,120 m 3 /s HEC RAS Tanjung Priok Plan: CW discharge 1 and 2 pump operation CW Discharge Channel Legend WS Q 39120 HWL Elevation (m) 4 2 0-2 HWL +0.42m LWL 0.56m Java Sea Training wall +2.90m WS +0.62m Stilling Basin WS +2.31m Seal Pit Pipe WS Q 39120 LWL Ground ROB -4-6 0 10 20 30 40 Main Channel Distance (m) 14
Two-pump operation, Q = 65,200 m 3 /s HEC RAS Tanjung Priok Plan: CW discharge 1 and 2 pump operation CW Discharge Channel Legend WS Q 65200 HWL Elevation (m) 4 2 0-2 HWL +0.42m LWL 0.56m Java Sea Training wall +2.90m WS +0.86m Stilling Basin WS +2.56m Seal Pit Pipe WS Q 65200 LWL Ground ROB -4-6 0 10 20 30 40 Main Channel Distance (m) 15
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 16
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 17
H e h d h d H e Y P d TW 2.15d c P 0.8d c L p 0.8d c L B L P + 2.55d c 18
Parameter Symbol Cooling water discharge 39,120 m 3 /h 65,200 m 3 /h Width of sill crest b 16 m 16 m Unit discharge q 0.6791 m 3 /s/m 1.1319 m 3 /s/m Critical depth d c 0.36 m 0.51 m Upstream head H e 0.62 m 0.87 m Drop height h d 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 d TW 5.62 m 5.87 m Distance of impinging jet from the sill L p 3.35 m 4.69 m Minimum distance of impact block from the L p + 0.8d c 3.64 m 5.09 m sill Minimum length of Stilling Basin L B L p + 2.55d c 4.27 m 5.78 m Minimum water depth in the Stilling Basin d TW 2.15 d c 0.78 m 1.09 m 19
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 20
Water Surface Profile Energy Dissipation Flow Velocity Flow Pattern 21
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 22
Acoustic Doppler Velocimeter to measure flow velocity Imaging technique to measure flow pattern Capacitance level meter to measure water level (dynamic) 23
Staff gauge, meter tape to measure distance, depth, elevation 24
Water surface profile Energy dissipation Flow pattern Flow velocity 25
Software EXEL Data of Water Level At Q h=14.6cm H=421mm H=375mm H=334.5mm 26
Flow Pattern (PIV) Light Sheet Source Model Camera 27
28
Instantaneous velocity (time average) velocity turbulence intensity and stress 29
30
31
32
33