Reconstruction of the SHPP Les Království HIDROENERGIA 2008, Bled, Slovenia Reconstruction of the Small Hydro Power Plant Les Království, Czech Republic

Reconstruction of the SHPP Les Království

HIDROENERGIA 2008, Bled, Slovenia

Reconstruction of the Small Hydro Power PlantLes Království, Czech Republic

Miloslav ŠlesingerKarel Kyzlink

Hidroenergia 200813th June 2008 – Bled, Slovenia



Introduction

In December 2003 ČKD Blansko Engineering, a.s., obtained a turkney contract for reconstructions of SHPP Les Království in Czech Republic. The goal of the reconstructions of this power plant was the replacement of an existing hydromechanical equipment produced in 1923.Supplies for the reconstruction included the technological part, the electrical part, and civil works.



Dam crest



Dam architecture



History of the dam and the small power station

Dam construction 1910–1919Power plant 1923Major overhaul 1952–1959Technical monument 1964Reconstruction 2005



Original technological equipment of the SHPP

Two horizontal-shaft twin Francis turbines (each was designed for a 4.5m3s-1 discharge, 600kW power and 428 rpm speed), produced by Českomoravská-Kolben in PragueTwo horizontal synchronous generators, produced by Fr. Křižík, PragueTwo hydraulic turbine governors, produced by PRAGA, Prague



Horizontal-shaft twin Francis turbine (cross section)



Horizontal-shaft twin Francis turbine (cross section)



Overall scope of the reconstruction

Technological equipment:Major overhaul of the intake structure emergency closing gateSealing of the penstockTurbines and generatorsPower house ventilation

Electrical part:Control systemLow voltage switch room, accumulator battery1600kVA and 250kVA transformers6.3kV and 35kV switch room

Civil part:Demolition worksConcrete structures



Solution of technological part reconstruction

The supply of new technological equipment consisted of:2 butterfly valves2 horizontal Francis turbines2 horizontal synchronous generators2 hydraulic control setmajor overhaul of the intake structure emergency closing gate



Solution of hydraulics

The flow in the discharge canal was simulated numerically in Fluent CFD software by two-phase flow simulation with free water level.Outlet canal capacity was evaluated because of the total discharge gain from 9 to 12 m3s-1

Height position of the draft tube discharge profile compared to outlet canal ground was analyzedDraft tube shape was optimized using CFD computations



Contour of velocity magnitude



Water flow in the outlet canal



Main technical parameters of the technological equipment

Turbine:

Horizontal Francis turbine with turbine runner overhung on the generator shaftRunner diameter 1040 mmDischarge 6 m3s-1 Speed 375 rpmHead 22.5 mMaximum power 1180 kWThe distributor servomotor is controlled by pressure oil from a hydraulic control set with 12MPa operational pressure



Horizontal Francis turbine (cross section)



Turbine and hydraulic control set



Generator:

Horizontal 3-phase synchronous generatorApperent power 1300 kVAWatt power 1108 kWNominal voltage 6300 VSpeed 375 rpmSliding generator bearing (one radial axial and one radial bearing)The generator is air-cooled



Horizontal 3-phase synchronous generator



Butterfly valve (in front of each turbine):

Diameter 1400 mmOpened by pressure oil from the hydraulic control set and closed by weight



Irrigation discharge pipe:

Diameter 500 mmCapacity 1,9 m3s-1

To ensure an automatic outlet of minimal discharge to the river when both turbines are shut down at the same time (butterfly valve opened by weight)



Process of operations on site:

Machines shut-down 1. 5. 2005Reconstruction started 2. 5. 2005

Work progress:Sealing of the penstock and dammimg and emptying the outlet canal under the power houseDisassembly of existing equipmentCivil worksInstallation of new technologyMajor overhaul of the emergency closing gateRepair of outlet canal concrete construction under the power houseDisassembly of the steel plugPerfoming tests

Works finished 30. 11. 2005



Intake sealing

Steel plug diameter 2400 mmDesign pressure 27m water columnInstallation on the penstock inner sheath by divers in the depth of about 16m



Disassembly of existing turbines, generators and governors

According to office of conservation project



Transport – incline lift



Transport of the spiral case



Civil works on draft tube unit 1



Spiral case unit 1



Turbine house after the reconstruction

Unit 2 Unit 1



Environmental precautions

Use of two-circuit cooling system of generator bearing lubrication aggregate with stainless steel cooling coil placed in the SHPP outlet canalInstallation of retaining tanks under hydraulic aggregatesSelf-lubricating fit of guide vane stemsSelf-lubricating wheel track stems and connecting rod stems of the emergency closing gate



Technical conditions (restrictions) of the reconstruction

Disassembly of existing turbines, generators and hydraulic governors according to office of conservation project (now being an exhibit of the National Technical Museum in Prague)Major overhaul of the emergency closing gate – the intake structure could not be temporarily dammed, so the dimensions had to be located by diversIn order to disassembly the existing butterfly valves and turbines and to install new ones, intake sealing by the steel plug was necessaryTransport conditions – all building material and equipment were transported using a incline lift with 8t load capacityAn expertise of the existing engineering constructions built between 1919 and 1923 was made in order to resolve transmission of load forces from the technology to existing concrete supporting structures. Its correct evaluation was needed to determine the rescue works procedure and facture and to install new technological equipment



Conclusion

Current operation of the machines has proved that projected power specifications have been achievedAll guaranteed parameters like power output and efficiency of newturbine-generator units and transformers were metThe benefit of the reconstruction was a complete renewal of the obsolete mechanical and electrical equipmentA higher utilization of present water resources potential during the year by as much as 40% was achieved thanks to the gain of flow rate through new turbines from 2 x 4.5m3s-1 to 2 x 6m3s-1 and the gain of maximum installed turbine power from 2 x 600kW to 2 x 1180kW



ČKD Blansko Engineering, a. s.Čapkova 2357/7

678 01 BlanskoCzech Republic

www.cbeas.com

„We do all for the future without polluted environment“

Documents

Reconstruction of the SHPP Les Království HIDROENERGIA 2008, Bled, Slovenia Reconstruction of the Small Hydro Power Plant Les Království, Czech Republic