Maintenance repair

Check the operating parameters of the generator set (measuring vibration and runout of the generator set) before repairing

1

Machine unit

Implementation content Measuring bearing vibration and machine body; Measure shaft runout; Check operating temperature; Record noise and unusual phenomena. Purpose: Assess operating condition before repair; As a basis for comparison after completing repairs. Equipment used (Vibration meter; Dialometer; Temperature measuring device; Vibration analysis device).

Chieng Ngam hydroelectric plant is located in Ban Chao Mua, Chieng La commune, Son La province

Check the impeller and measure its size before repairing

1

All

Inspection content Check the size when disassembling. Purpose: Ensure after restoration to original size.

Chieng Ngam hydroelectric plant is located in Ban Chao Mua, Chieng La commune, Son La province

Remove the impeller and turbine baffle

1

All

Implementation content Isolation of power and energy sources; Remove the linkage assemblies; Use lifting equipment to remove the working wheel; Preliminary cleaning after disassembly. Technical requirements Do not cause deformation of details; Ensure equipment and personnel safety; Fully record the status after disassembly.

Chieng Ngam hydroelectric plant is located in Ban Chao Mua, Chieng La commune, Son La province

Check the working wheel and turbine partition of the unit after disassembly

1

All

- Inspection method a) Visual inspection Assess the level of wear; Cavitation test; Check surface deformation. b) Liquid penetrant testing (PT) To detect: Surface cracks; Air pitting; Open defects. - Results Prepare a record to determine the location, size and extent of defects; Determine the scope of repair and restoration.H11

Chieng Ngam hydroelectric plant is located in Ban Chao Mua, Chieng La commune, Son La province

Surface treatment of working wheels and turbine partitions

1

All

Implementation content: Grinding to remove corroded metal layer; Grinding to remove corroded metal 17 BXCT wings; Completely eliminates cracks and defects; Cleans grease, oxidation and impurities. Requirements Thoroughly clean surface; No more defects affecting welding quality; Create suitable roughness for metal bonds.

Chieng Ngam hydroelectric plant is located in Ban Chao Mua, Chieng La commune, Son La province

Welding (compensatory welding of 4mm thick impeller) and repair of impeller and turbine baffle

1

All

Welding method Manual arc welding or TIG/MIG welding depending on the material; Compensation welding of 17 wings BXCT; Multi-layer, multi-path welding; The average restoration weld thickness is about 4 mm. Welding materials Use welding rods/welding materials suitable for the impeller material; Welding materials have quality certificates. Technical measures Pre-weld heating if necessary; Temperature control between solder layers; Limit heat distortion; Clean slag after each layer of welding. Require uniform weld quality; No cracking, no porosity; Ensures mechanical durability and cavitation resistance.

Chieng Ngam hydroelectric plant is located in Ban Chao Mua, Chieng La commune, Son La province

Machining and creating hydraulic profiles (Grinding and creating working wheel profiles)

1

All

Contents of Fine Grinding; Surface polishing; Recreate the wheel blade profile according to the design. Technical requirements Correct geometrical dimensions; Surface smoothness meets requirements; Ensure symmetry and hydrodynamics.

Chieng Ngam hydroelectric plant is located in Ban Chao Mua, Chieng La commune, Son La province

Check the impeller and turbine baffles after repair (measure dimensions, check for defects by liquid permeation method)

1

All

Inspection content Check size; PT check; Purpose: To ensure no remaining defects; Ensure the quality of welds and repair areas.

Chieng Ngam hydroelectric plant is located in Ban Chao Mua, Chieng La commune, Son La province

Dynamically balance the working wheel

1

All

Implementation content Checking imbalance; Add or remove correction volumes; Check again after balancing. Purpose: Reduce vibration; Ensure stability when operating; Increase bearing and machine unit life.

Chieng Ngam hydroelectric plant is located in Ban Chao Mua, Chieng La commune, Son La province

Reinstall the working wheel and turbine partition into the unit

1

All

Implementation content: Reinstall the working wheel; Concentric alignment; Check technical gaps; Tighten the bolt to the correct torque. Requires good Concentricity; No collision occurs; Ensure safe operating conditions.

Chieng Ngam hydroelectric plant is located in Ban Chao Mua, Chieng La commune, Son La province

Run a test to check the operating parameters of the generator set (measuring vibration, runout and dynamic balance of the generator set) after repair

1

Machine unit

Test run content Idling; Running under load; Vibration measurement; Measure runout; Check temperature and noise. Acceptance criteria Operating parameters reach allowable limits; No unusual vibrations or noises appear; The unit operates stably and continuously.

Chieng Ngam hydroelectric plant is located in Ban Chao Mua, Chieng La commune, Son La province

Static zigzag rim

1

Female

Technical specifications - Material: SUS304 steel - Weight: 25kg

Chieng Ngam hydroelectric plant is located in Ban Chao Mua, Chieng La commune, Son La province

Pillow bearing silver 1

1

Set

Technical specifications - Unit: mm - Silver case: C45 steel - Casting material: Babit B83 - Weight: 120 kg

Chieng Ngam hydroelectric plant is located in Ban Chao Mua, Chieng La commune, Son La province

Pillow bearing silver 2

1

Set

Technical specifications - Unit: mm - Silver case: C45 steel - Casting material: Babit B83 - Weight: 33 kg

Chieng Ngam hydroelectric plant is located in Ban Chao Mua, Chieng La commune, Son La province

Turbine blade bearings

1

Female

Technical specifications - Unit: mm - Casting material: Copper - Weight: 400 g

Chieng Ngam hydroelectric plant is located in Ban Chao Mua, Chieng La commune, Son La province