Restoration Project of Derbendikhan and
Dokan Hydropower Station
- The Derbendikhan Hydropower Project is scheduled to be completed in 40 months, while the Dokan Hydropower Project is scheduled to be completed in 50 months.
- Construction site planning and construction sequence:
In the installation room, there are stator stations, rotor stations, runner stations, and frame stations for cleaning, inspection, repair, and assembly of corresponding equipment. Following the Owner’s delivery of the unit to us, restoration and repair will be carried out in accordance with the construction sequence of a single unit.
- Disassembly and maintenance of generator:
Lower guide bearing, flange bolt and protective cover, rotor, lower frame, lower pedal, oil and gas pipeline, etc. are disassembled and hoisted. Likewise, upper bearing, thrust bearing, upper cover plate, upper frame, upper and lower wind shield are lifted.
- Disassembly and maintenance of turbine:
After the turbine equipment is removed, it is cleaned, inspected, and repaired in the installation room or corresponding unit section, and any equipment or parts that do not meet service performance are replaced.
- Inspection and treatment of diversion pipe, spiral case and draft tube:
Diversion pipe, spiral case, and draft tube inspection and treatment mostly entail spiral case, draft tube, draft tube garbage rack, drainage valve, guiding vane, stay ring, foundation ring, and inlet channel examination and repair of damaged components.
- Installation of turbine equipment:
Pit measurement, pre-assembly of the water guide mechanism, hoisting of the runner and main shaft, installation of the water guide mechanism, installation of the water guide bearing, installation of the main shaft and maintenance seal, and so on are the main procedures of turbine installation.
- Installation of generator equipment:
During the assembly of the rotor in the installation room, the rotor assembly
procedures are as follows: construction preparation → rotor removal → rotor bracket leveling → installation of the roundness measuring frame → yoke stacking → yoke hot pressing → pole mounting → pole lead installation → painting → rotor hoisting → overall rotor test.
- Maintenance of main inlet valve and auxiliary equipment:
In order to address the valve group leakage, the primary inlet valve will be completely refurbished and the hydraulic oil and sealing ring will be replaced. Hydrostatic operation testing, waterless operation testing, automatic operation testing, among other tests, must be done after maintenance.
- Inspection and maintenance of lifting equipment:
Examine the lifting equipment’s mechanical parts and equipment, electrical equipment, and lifting accessories, and make a list of the maintenance items. Replace aging cable, remove rust from rusted metal equipment parts, and paint in accordance with design specifications.
- Maintenance of hydraulic machinery auxiliary equipment:
The auxiliary equipment of hydraulic machinery includes water supply system,
drainage system, compressed air system, oil system, hydraulic measurement system, generator fire protection system, etc.
- Maintenance of gate and metal structure:
Gate and metal structure maintenance primarily consists of equipment inspection and repair, gate slot inspection, gate sealing replacement, hoist cable replacement and testing, penstock leakage maintenance, anti-corrosion, and so on.
- Transformer installation
- Installation of monitoring, protection, communication and auxiliary control system equipment
- Cable trays and cables
- Maintenance and installation of automation components
- Installation of DC system equipment
- inspection and preventive test of electrical equipment
- Unit commissioning and trial operation