Overview of Air Compressor Systems

Air compressors are fundamental to industrial automation, converting mechanical energy (typically from an electric motor) into compressed air energy. This document focuses on screw-type air compressors, commonly used in power generation systems for ash handling and instrument air supply.

Common Alarms and Faults

• Temperature Alarms: High temperature at the compressor outlet (110°C alarm, 120°C shutdown).
• Pressure Alarms: High pressure at the compressor outlet (10 bar alarm, 15 bar shutdown).
• Oil Separator Issues: Clogging of the oil separator filter, leading to increased pressure differential.
• Air Filter Issues: Clogging of the air filter, causing negative pressure at the compressor inlet.
• Oil Filter Issues: Clogging of the oil filter due to impurities.
• High Oil Temperature: Caused by oil aging, poor oil return, or oil loss.
• Low Oil Level: Indicated by low oil level in the oil separator.
• Line Pressure Issues: Overloading or unloading pressure control problems.

Common Faults and Handling

• Power Loss: Check the power supply to the compressor.
• Motor Overheating: Reduce motor load and ensure proper cooling.
• Compressor Overheating: Ensure proper ventilation, check oil levels, and inspect cooling fans.
• High Pressure: Adjust the load pressure settings and inspect pressure sensors.
• Motor Rotation Error: Check motor wiring and rotation sensors.
• Maintenance Alerts: Perform regular maintenance and reset maintenance timers.
• Cooling System Failure: Inspect cooling fans, relays, and wiring.
• Oil Pressure Issues: Check oil levels, oil lines, and oil pumps.

Operational Modes

Air compressors can operate in two modes:

• Continuous Operation: Used for systems with high air demand, such as ash handling.
• Automatic Operation: Used for systems with low air demand, such as instrument air supply.

Maintenance and Inspection

• Check oil levels regularly and top up if necessary.
• Monitor air pressure and temperature during operation.
• Inspect for unusual noises or vibrations.
• Ensure proper functioning of unloading and loading pressure settings.
• Check for oil or air leaks in pipelines and connections.

Dryer System Faults and Maintenance

The dryer system is crucial for removing moisture from compressed air. Common issues include:

• High Refrigerant Pressure: Caused by excessive refrigerant, high cooling water temperature, or clogged condensers.
• Low Refrigerant Pressure: Due to insufficient refrigerant or cooling water issues.
• Poor Drying Performance: Caused by faulty heaters, high air moisture, or excessive air flow.