Hydel Power Generation Applications

Hydel plants face a constant battle with high moisture ingress, condensation and water emulsion. Water contamination causes rapid oil hydrolysis, strips out protective additives, and causes corrosive pitting on critical components. To prevent devastating shutdowns and environmental oil leaks into rivers, maintaining a strict NAS 4 to NAS 6 cleanliness level is standard industry practice.

The primary lube and hydraulic oil filtration applications in hydel plants include:

1. Main Turbine Bearing Lubrication

• Continuous De-watering: Water constantly tries to seep past shaft seals into the main turbine oil sump (typically containing ISO VG 46 or 68 turbine oil). Online vacuum dehydration filtration machines are permanently hooked up to boil off free, emulsified, and dissolved water down to under 100 ppm.
• Preventing Metal Scuffing: Abrasive particulate filtration down to 3 microns ensures that the thin hydrodynamic oil film separating the rotating shaft from the bearing face remains entirely free of wear metals, preventing catastrophic bearing wipeouts.

2. Governor Hydraulic Systems & OPU (Oil Pressure Unit)

The governor system regulates the opening and closing of guide vanes (wicket gates) to control water flow into the turbine, maintaining grid frequency.

• Proportional and Servo Valve Protection: Governor systems operate at high pressures and rely on highly sensitive servo valves with micro-clearances. RTES depth filtration machines eliminate fine silt and varnish that cause valve sticking, which could otherwise lead to a dangerous loss of turbine speed control.
• Accumulator Maintenance: Offline conditioning loops keep the fluid inside the main high-pressure hydraulic accumulator banks completely clean and dry.

3. Generator Transformer Oil Conditioning

While not a lubricant, insulating transformer oil inside the plant's step-up transformers requires identical filtration technology.

• Dielectric Strength Restoration: High-vacuum oil purifiers are deployed to degas, dehydrate, and filter transformer oil. Removing dissolved gases and moisture restores the oil's breakdown voltage (BDV) to ensure grid safety.
• Hydraulic Oil Purification Machine — Application: Multi-purpose mobile cart used for flushing out governor lines, oil pressure units (OPUs), and auxiliary plant hydraulics during annual maintenance shutdowns.