Compressors : More Compressors

 Scroll Compressors:

• Scroll compressors are more efficient than reciprocating compressors with fewer moving parts and no clearance volume, resulting in no re-expansion of discharge gases.

• They feature two scrolls: a fixed scroll and an orbiting scroll. As the orbiting scroll rotates, it creates pockets that continuously compress refrigerant vapor.

• The compressed refrigerant is discharged from the center of the scrolls.

Rotary Compressors:

• Rotary compressors use a roller (or piston) and a spring-loaded vane to compress refrigerant vapor. These compressors are commonly used in domestic refrigeration, air conditioning, and heat pump applications.

• Rotary compressors are often referred to as "high side compressors" because their shells contain discharge vapor, making them hot to the touch.

• An accumulator is used to prevent liquid refrigerant from entering the compressor, which could cause severe damage.

Centrifugal Compressors:

• Centrifugal compressors are typically used in industrial applications, such as water chillers. They use an impeller that spins at high RPMs to compress refrigerant via centrifugal force.

• These compressors often feature a variable frequency drive motor, which adjusts the compressor's speed to match the heat load requirement. Some centrifugal compressors are oil-free and use magnetically levitated bearings.

Screw Compressors:

• Screw compressors are used in larger commercial and industrial applications. They use asymmetric rotors that rotate against each other, compressing refrigerant as it moves through the system.

• These compressors include timing gears, shaft seals, cooling jackets, and anti-friction bearings to enhance their performance and durability.