Electrical Revolution

Energy conservation in compressor

Here the some of the useful tips / techniques for energy conservation in compressor is given. The compressor is used where the air pressure required is higher than the atmosphere pressure. The applications of compressor include automative, aerospace, chemical manufacturing, hospitals, pharmaceuticals, plastics, power generation, wood products etc.

Tips / Techniques for energy conservation in compressor

Compressor oil

Use a synthetic lubricant if the compressor manufacturer permits it.

Be sure lubricating oil temperature is not too high (oil degradation and lowered viscosity) and not too low (condensation contamination).

Change the oil filter regularly.

Compressor intercoolers

Periodically inspect compressor intercoolers for proper functioning.

Variable speed drive

Consider variable speed drive for variable load on positive displacement compressors. Consider engine-driven or steam-driven air compression to reduce electrical demand charges. Use a small air compressor when major production load is off.

Waste heat recovery

Use waste heat from a very large compressor to power an absorption chiller or preheat process or utility feeds.

Compressor efficiency

Establish a compressor efficiency-maintenance program. Start with an energy audit and follow-up, then make a compressor efficiency-maintenance program a part of your continuous energy management program.

Compressed air

Establish a compressed air efficiency maintenance program. Make energy audit and follow up, take compressed air efficiency as a part of energy management program.

Part load management

Install a control system to coordinate multiple air compressors. Study part load characteristics and cycling costs to determine the most-efficient mode for operating multiple air compressors.

Avoid over sizing -- match the connected load.

Load up modulation-controlled air compressors. (They use almost as much power at partial load as at full load.)

Compressor air pressure

Turn off the back-up air compressor until it is needed.

Reduce air compressor discharge pressure to the lowest acceptable setting.

Reduction of 1 kg/cm² air pressure (8 kg/cm²to 7 kg/cm²) would result in 9% input power savings. This will also reduce compressed air leakage rates by 10%.

Compressed air leakage

Minimize purges, leaks, excessive pressure drops, and condensation accumulation. (Compressed air leak from 1 mm hole size at 7 kg/cm² pressure would mean power

loss equivalent to 0.5 kW)

Check for leaking drain valves on compressed air filter/regulator sets. Certain rubber type valves may leak continuously after they age and crack.

Use of V belts

Replace standard v-belts with high-efficiency flat belts as the old v-belts wear out.

Alternatives for compressed air

Consider alternatives to compressed air such as blowers for cooling, hydraulic rather than air cylinders, electric rather than air actuators, and electronic rather than pneumatic controls.

Use the highest reasonable dryer dew point settings.

Turn off refrigerated and heated air dryers when the air compressors are off.

Use a control system to minimize heatless desiccant dryer purging.

Use drain controls instead of continuous air bleeds through the drains.

Air intake in compressor

Take air compressor intake air from the coolest (but not air conditioned) location. (Every 5⁰ C reduction in intake air temperature would result in 1% reduction in compressor power consumption)

Use an air-cooled after cooler to heat building makeup air in winter.

Monitor pressure drop

Monitor pressure drops across suction and discharge filters and clean or replace filters promptly upon alarm.

Heat exchange & air separators

Be sure that heat exchangers are not fouled (e.g. -- with oil).

Be sure that air/oil separators are not fouled.

Oil water separator

Use a properly sized compressed air storage receiver. Minimize disposal costs by using lubricant that is fully demulsible (ability of oil separate from water) and an effective oil-water separator.