Sunkoshi Small Hydropower Project

GENERAL INFORMATION
Project Type	Run-of-River
Installed Capacity	2.60 MW
Number of units	2
Gross head	124.50 m
Net energy	14.38 GWh
HYDROLOGY
Catchment area	81.00 km²
Average annual flow	5.77 m³/s
Design discharge	2.7 m³/s
Minimum monthly flow	1.10 m³/s
Compensation flow	90.00 l/s
Project design floods
20-years	130.00 m³/s
100-years	325.00 m³/s
500-years	460.00 m³/s
HEADWORKS
Weir
Weir length	36m
Weir crest level	952.50 m amsl
Weir height (Above river bed)	2.00 m
Weir discharge capacity	368.00 m³/s
Intake
Bottom orifice sill level	951.50 m amsl
Intake orifice size	1.50 m x 0.30 m (2 x 4 nos)
Design discharge including gravel flushing and sediment flushing	368.00 m³/s
Maximum intake capacity	8.00 m³/s
Intake culvert
Total length	60.00 m
Canal slope	1 in 50
Size	1.29 x 2.20 m with 0.25 m freeboard at 100 years flood
Gravel trap
Length (including transition)	18.40 m
Width	4.00 m
Settling length	20.00 m
Flushing discharge	0.80 m³/s
Flushing gate	1 no. size 0.60m x 0.75m
Particle size to be settled	5mm
Gravel flushing channel
Type	Rectangular with hard stone lining
Length	12.50 m
Width	1.00 m x 1.50 m
Slope	1:35
Pipe Crossing
Truss bridge length	30.00 m
Pipe crossing	40 m long 1300 dia 6 mm thick MS pipe
Approach canal
Length	220.00 m
Size	1.60 m x 1.50 m
Slope	1:530
Settling basin
Length (including transition)	77.00 m
Settling chambers	2 nos., 4.50 m wide each
Settling length	45.00 m
Flushing discharge	1.08 m³/s
Particle size to be settled	0.2 mm
Particle trapping efficiency	90%
Sediment flushing gate size	2 nos. 0.6m x 0.6m
Sediment flushing channel
Type	Rectangular
Length	23.00 m
Size	1.20 m x 1.00 m
Slope	1:30
Forebay
Size	10.00 m x 10.50 m x 5.60 m
Pressure Pipe
Type	Buried and exposed
Material	GRP and mild steel
Total length	25.50 m
Internal diameter	1200mm and 1300mm
POWERHOUSE
Type	Surface
Size	18.00 m wide and 24.00 long
Turbine axis level	825.50 m amsl
TAILRACE
Type	Open canal structure
Length	43.00 m
Tail water level	819.00 m amsl
ELECTRO-MECHANICAL EQUIPMENTS
Turbine
Turbine type	Turgo
Model	XJA – 60A/2 x14.5
Number of units	2 nos.
Rated capacity	1317 kW each
Efficiency	85%
Turbine inlet valve	Gate valve
Powerhouse crane	Overhead travelling crane
Capacity	10 tons
Generator
Model	SFW 1250-10/ 1430
Rated Output	1250 kW each
Rated frequency	50 hz
Rated Current	143.2 A
Rated Voltage	6300 V
Power factor	0.8
Rated speed	750 rpm
Insulation Degree	F/F
Main Transformer
Model	S93150-11/6.3
Rated Capacity	3150 kVA
Voltage	6.3 kV to 11 kV
Service Power Transformer
Model	S9-M-63/6kV
Rated Capacity	63 kVA
Excitation Transformer
Model	ZSJ-50/ 6 kVA
Rated capacity	50 kVA
Transmission line
Line length	6.3km long, 11kV, single circuit
Switchyard	17 m x 15 m (approx.)
POWER AND ENERGY
Design discharge	2.70 m³/s
Gross head	125.5 m
Net head at full flow	117.5 m
Installed capcity	2.6 MW
Total energy per year	14.38 GWh
Power evacuation	At 11 kV Sunkoshi Substation, Phurketar, Lamosanghu, NEA HT switchboard 11 kV, 25 kA with copper Bus bar rated 2000 A consisting of incomer panel