Screw compressor is a new compression device, compared with reciprocating:
advantage:
①The machine is compact in structure, small in size, small in floor space and light in weight.
②The thermal efficiency is high, the number of processed parts is small, and the total number of parts of the compressor is only 1/10 of that of the piston type. The machine has few wearing parts, safe and reliable operation, and simple operation and maintenance.
③There is no gas pulsation, the operation is stable, and the foundation of the unit is not high and does not require a special foundation ④Oil is injected into the rotor cavity during operation, so the exhaust temperature is low.
⑤ Not sensitive to wet stroke, there is no risk of liquid shock when wet steam or a small amount of liquid enters the machine.
⑥ It can operate at a higher pressure ratio.
⑦The effective stroke of compression can be changed by means of the slide valve, and 10~100% of the cooling capacity can be adjusted steplessly.
shortcoming:
Complex oil treatment equipment is required, and equipment such as oil separators and oil coolers with good separation effects are required. The noise is relatively loud, generally above 85 decibels, and sound insulation measures are required.
Compared with the piston type, the centrifugal type has high speed, large air volume, small mechanical wear, few wearing parts, simple maintenance, long continuous working time, small vibration, stable operation, low requirements on the foundation, and the unit power The unit is light in weight, small in size, occupies a small area, and the gas volume can be adjusted steplessly within the range of 30% to 100%. It is easy to multi-stage compression and throttling, and can meet the requirements of certain chemical processes. It is easy to realize automation. Large machines can be directly driven by industrial steam turbines with high economical efficiency, which has economic advantages for enterprises with waste heat steam. The disadvantages are: the noise frequency is high, the cooling water consumption is large, and surge will occur when the operation is improper.
Among the three common types of refrigeration compressors (reciprocating, screw, and centrifugal), the inertia caused by reciprocating motion is the main disadvantage of reciprocating refrigeration compressors. The valves and crank linkages in reciprocating refrigeration compressors are the most vulnerable to failure because they are often subjected to the inertia of reciprocating motion.
Among the three common refrigeration compressors (reciprocating, screw, and centrifugal), the loud noise generated during operation is the main disadvantage of the screw refrigeration compressor. Because it is often affected by the periodic high-speed passage of refrigerant gas through the suction and exhaust ports, and the leakage through the gap, a reasonable screw operating speed must be selected in the screw refrigeration compressor.
Among the three common types of refrigeration compressors (reciprocating, screw, centrifugal), surge is the main disadvantage of centrifugal refrigeration compressors.
