Trishuli Jal vidhyut Company Limited

Salient Features of Upper Trisuli 3B Hydroelectric Project :
Project Location
Province	3
Zone / District	Bagmati / Nuwakot and Rasuwa
Intake Site	Kispang Rural Municipality (Nuwakot) and Uttargaya Rural Municipality (Rasuwa)
Powerhouse Site	Kispang Rural Municipality (Nuwakot)

General
Name of River	Trishuli River
Nearest Town	Trishuli Bazar
Type of Scheme	Run-of-River
Maximum Gross Head	90.0 m
Net Head	85.37 m
Installed Capacity	37 MW
Average Annual Energy	304.78 GWh
Average Annual Energy after Outage	292.59 GWh

Hydrology
Catchment Area	4577 km2
Mean Annual Discharge	192 m3/sec
Design Discharge (at Q70% PoE)	51 m3/sec (Tailrace water of Upper Trishuli 3A)
Riparian Release	3.84 m3/sec
1000 Yrs Flood Discharge	2718 m3/sec

Headpond (Connected to UT3A Tailrace Pond)
Size	29 m x 5.2 m to 11.2 m x 7.35 m to 16.8 m
Lowest Bed Level	EL. 712.20 m

Intake
Type	Bellmouth
Intake Invert Level	EL. 714.90 m
Submergence Depth	6 m

Approach Pressure Conduit
Type	Box Culvert and Steel Pipe embedded in concrete
Box Culvert Length	276 m
Box Culvert Size	5.1 m x 5.1 m
Steel Pipe Length	40 m
Diameter of Pipe	5.10 m

Headrace Tunnel
Shape	Circular for concrete lined and horseshoe for shotcrete lined section
Length	3666 m
Diameter	5.20 m for concrete lined and 6.0 m for shotcrete lined
Portal Invert Level	EL. 714.90 m

Adit Tunnel
Shape	Inverted D
No. of Adit Tunnels	2
Length of Adit-1 Tunnel	463.6 m
Diameter of Adit-1 Tunnel	4.0 m
Length of Adit-2 Tunnel	100 m (Indicative)
Diameter of Adit-2 Tunnel	5.0 m (Indicative)

Surge Tank
Type	Restricted Orifice
Diameter of Tank	15.0 m
Height	24.6 m
Throttling Diameter	2.0 m
Level of Surge Tank Crown	EL. 736.3 m
Bottom Elevation of Surge Tank	EL. 711.7m

Pressure Tunnel After Penstock Stoplog
Section	Circular
Diameter	4.20 m
Length	33 m (including transition from square to circular pressure tunnel)
Concrete Lining Thickness	300 mm
Pipe Shell Thickness	14 mm

Inclined Shaft
Type	Circular
Diameter	4.20 m
Length	100 m
Lining Thickness	300 mm (Concrete) & 100 mm (Shotcrete)
Pipe Shell Thickness	14 mm

Pressure Tunnel After Inclined Shaft
Type	Circular
Diameter	4.20 m
Length	24.0 m
Lining Thickness	300 mm
Pipe Shell Thickness	14 mm

Penstock After Bifurcation (Penstock Manifold)
Type	Circular
Diameter	3.0 m
Length	15.0 m (including transition)
Steel Lining	14.0 mm

Powerhouse
Type	Surface
Size (L x B x H)	37.60 m x 14 m x 28.2 m
Center line of Turbine	EL. 634.5 m

Tailrace Conduit
Type	RCC, Conduit
Length	129.6 m
Size (B x H)	6.7 m x 5.0 m
Tail Water Level	EL. 637.5 m

Turbine
Type	Vertical Axis, Francis
No. of Units	Two (2)
Rated Output Capacity per unit	19.1 MW
Efficiency	92.5 %

Governor
Type	Electronic with PID Control
Adjustment for Speed Drop	Between 0 to 5 %

Generator
Type	Synchronous, 3 Phase
No. of Units	Two (2)
Rated Output Capacity per Unit	22 MVA
Power Factor	0.85
Rated Voltage	11 kV
Frequency	50 Hz.
Rated Speed	375 rpm
Excitation System	Static
Efficiency	97%

Transformer
Type	Outdoor, Oil Immersed, 3 Phase, ONAN
No. of Units	Two (2)
Rated Capacity per Unit	23 MVA
Frequency	50 Hz.
Vector Group	YNd 5
Voltage Ratio	11 kV/ 132 kV
Efficiency	99%

Transmission Line
Voltage Level	132 kV, Single Circuit
Length	3 km
Conductor	ACSR "BEAR"
From	Powerhouse
To	Proposed Trishuli 3B Hub

Construction Period	36 months

Salient Features