Rotary Compressors
Rotary compressors use an electric motor to turn the rotating parts in the stationary element to compress the refrigerant vapor. Rotary compressors are available in four basic designs: piston sliding, rotating blades, helical rotary screw and scroll. All these compressors three-dimensional structures that compress refrigerant vapor without conversion shaft rotation in reciprocation. Although rotary compressors, reciprocating engines, their rotational motion produces a smoother, almost constant stream of suction and discharge vapors. In the performance reduces the level of stress in the compressor, and the reduction of the pair of pulsations reduces vibration and noise made by these compressors. Rotary compressors have fewer moving parts than reciprocating compressors, simplify their production and cost.
Similar to the piston colleagues, rotary compressors also experience volumetric compression and losses. These inefficiencies in the result of processing the volumes of cylinders, heating, valve leakage, impact and valve flow characteristics present in rotor machines.
However, these inefficiencies, as a rule, less than diose in reciprocating devices. Gap volumes and associated with the enlargement of the clearance pairs, comparatively small in rotary compressors. Therefore, their volumetric efficiency, relatively high (65 to 80%), depending on the compressor design and operating conditions.
The capacity of the compressor rotor directly depends on speed of rotation of the shaft of the rotor. Because these compressors are usually driven constant speed induction motor, the performance management is most often achieved by varying the volume of the refrigerant vapor input compression pocket rotor. This is often achieved by removing the low vapour pressure of the refrigerant in the low degree of compression on a bypass passage, situated between compression pocket and suction line. This strategy leads to partial compression of the General flow of steam...
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Industrial