Turbine maintenance is a complex and crucial task, typically categorized into three levels based on the scope of repair: minor, medium, and major. Below is a detailed description of turbine maintenance:

Minor repairs

Minor repairs primarily involve local inspections and repairs of the steam turbine to eliminate certain defects and malfunctions identified during operation. Specifically includes:

1. Inspect and repair bearings with high running vibration or shaft displacement.

2. Inspect and repair bearings with higher operating temperatures and the corresponding upstream and downstream oil lines.

3. Eliminate dripping, leaking, and seeping issues from various pipelines, valves, and flanges.

4. Eliminate other malfunctions and defects that occur during operation.

Part Two: Mid-term Maintenance

Mid-level maintenance involves inspecting and repairing turbines based on the scope of minor maintenance. Specifically includes:

1. Includes all aspects of minor repairs.

2. Disassemble and inspect radial and thrust bearings, measure the washer thickness, washer back tension, oil seal gap, shaft end play, and partial shaft end play; adjust or replace parts as necessary.

3. Inspect the condition of the shaft collar and thrust plate; make adjustments as necessary.

4. Clean and inspect couplings, coupling bolts, cylinder slide pins, and other components; measure relevant gaps and float amounts; check the fit and wear of internal and external spline sleeves.

5. Inspect and adjust all major pipeline supports and spring hangers.

6. Clean and inspect critical circuit breakers, measure relevant gaps.

7. Inspect and clean the actuator mechanism of the regulating valve, and test the operation of the main gas valve.

8. The regulating system undergoes static debugging, and the steam turbine is subjected to overspeed tests (performed during annual major maintenance).

9. Main condensate pump and main lubricating oil pump disassembly and maintenance.

10. Re-inspection of the equipment overhaul is to be accurate, and alignment updates to be made after overhaul.

3. Major Overhaul

Major overhaul involves inspection and modification of the steam turbine to restore its performance and enhance its reliability. The overhaul projects typically include the following aspects:

The main body

1. CylinderInspect cylinders and nozzles for cracks, erosion, and damage. Treat as necessary. Measure the horizontal level of the cylinder and clearances at the mating surfaces, then trim and grind the mating surfaces for tightness. Check the cylinder sliding pin system, clean and adjust the sliding pin clearances to ensure smooth expansion.

2. RotorPerform macroscopic examination of the rotor to check for cracks, damages, or corrosion in areas such as the shaft neck, impeller, and blades. Measure the deflection, vibration, and跳动 values of the rotor; if they exceed the standard, correction is required. Inspect the integrity of the blade bracing and girth band connections, and repair or replace any loose or damaged parts. Conduct dynamic balancing tests on the rotor to ensure smooth operation.

3. Steam sealInspect the steam seal teeth for wear and deformation, and replace them if necessary. Adjust the steam seal gap to ensure the sealing integrity of the steam seal and minimize steam leakage.

4. BearingsInspect for wear, delamination, cracks, and other defects on the bearing's black metal surface, and repair or replace as necessary. Measure bearing clearance and tension, adjusting to the standard range. Check if the foot bolts and connecting bolts of the bearing base are loose, and tighten them if needed.

5. Wheel ChangerInspect the gear, worm gear and worm, motor, and other components of the turbine setter for integrity and proper operation. Adjust the turbine setter to ensure reliable engagement during the startup and shutdown of the steam turbine.

Speed Control System

1. Speed controllerInspect the integrity of the speed controller's components and ensure smooth and accurate operation. Clean the oil passages of the speed controller and replace the filter element to ensure proper functioning. Adjust and calibrate the speed controller, modifying speed parameters to meet the turbine's operational requirements.

2. Oil engineInspect the condition of the oil motor's piston, cylinder, seals, and other components for integrity and leaks. Measure the stroke and speed of the oil motor, adjusting it to the standard range. Check the connection between the oil motor and the governor, as well as the control valve, for firmness and coordination.

3. Regulating Valves and Drive MechanismsInspect the valve core and seat of the regulating valve for wear and corrosion, and repair or replace as necessary. Check the integrity and flexibility of the transmission mechanism, such as rods, levers, springs, etc., and ensure smooth operation. Adjust the regulating valve to ensure its smooth and tight opening and closing, with control accuracy meeting requirements.

Auxiliary System

1. CondenserInspect the heat exchange tubes of the condenser for blockages or leaks, and clean or seal them as necessary. Check for corrosion or cracks in the condenser's water chamber, nozzle, tube sheet, and other parts, and take appropriate measures. Measure the vacuum degree of the condenser, verify the functionality of the exhaust system, and address any issues found.

2. Lubrication SystemInspect the fuel tank, oil pump, oil cooler, oil filter, and other equipment for integrity and leaks. Clean the fuel tank and oil system pipes, and replace the lubricating oil. Check parameters such as oil pressure, oil temperature, and oil level for normalcy and adjust to the standard range. Examine the tightness of valves, flanges, and other connection points, and address any leaking areas. Conduct a hydrostatic test on the steam-water system to check for system tightness.