1. Screw compressor
Screw type air compressor. Oil-injected screw air compressors are used in refrigeration devices. Because of their simple structure and few wearing parts, they can have low exhaust temperature under working conditions with large pressure differences or pressure ratios, and provide a large amount of lubrication to the refrigerant. Oil (often referred to as wet stroke) is not sensitive and has good air flow regulation. It quickly occupied the application range of large-capacity reciprocating compressors, and it continued to extend to the medium-capacity range, and was widely used in freezing and cold storage. , Air conditioning and chemical technology and other refrigeration equipment.
2. Centrifugal compressor
A centrifugal compressor is a vane rotary compressor (that is, a turbo compressor). In a centrifugal compressor, the centrifugal force given to the gas by the high-speed rotating impeller and the diffuser effect given to the gas in the diffuser channel increase the gas pressure. In the early days, because this compressor was only suitable for low, medium pressure and large flow occasions, it was not noticed by people. Due to the development of the chemical industry and the establishment of various large-scale chemical plants and refineries, centrifugal compressors have become a key machine for compressing and transporting various gases in chemical production, and occupy an extremely important position. With the achievements of gas dynamics research, the efficiency of centrifugal compressors has been continuously improved, and
Due to the successful development of key technologies such as high pressure sealing, small flow and narrow impeller processing, and multi-oil wedge bearings, it has solved a series of problems in the development of centrifugal compressors to high pressure and wide flow range, making the application range of centrifugal compressors wider Expansion, so that it can replace reciprocating compressor in many occasions, and greatly expand the scope of application.
3. Reciprocating piston compressor
It is one of the earliest developed types of compressors. Piston compressors have a long history of use and are currently the most used compressors. Because of its wide pressure range, it can adapt to a wide energy range, and has the advantages of high speed, multiple cylinders, adjustable energy, high thermal efficiency, and suitable for various working conditions; its disadvantages are complex structure, many vulnerable parts, and short maintenance cycle , Sensitive to wet stroke, impulse vibration, poor running stability.
Screw compressor is a new compression device, which is compared with reciprocating type:
①The machine has compact structure, small volume, less floor space and light weight.
②High thermal efficiency, fewer machining parts, and the total number of compressor parts is only 1/10 of the piston type. The machine has few wearing parts, safe and reliable operation, and simple operation and maintenance.
③The gas has no pulsation, and the operation is stable. The unit has a low foundation and no special foundation is needed.
④Inject oil into the rotor cavity during operation, so the exhaust temperature is low.
⑤Insensitive to wet stroke, wet steam or a small amount of liquid enters the machine, there is no danger of liquid shock.
⑥ It can be operated at a higher pressure ratio.
⑦The effective stroke of compression can be changed with the help of slide valve, and the stepless cooling capacity can be adjusted from 10 to 100%.
Complicated oil treatment equipment is required, and equipment such as oil separators and oil coolers with good separation effects are required. The noise is relatively large, generally above 85 decibels, and sound insulation measures are required.
Compared with the piston type, the centrifugal type has high speed, large air volume, less mechanical wear, less wearing parts, simple maintenance, long continuous working time, small vibration, stable operation, low basic requirements, and unit power when the air volume is large. The unit is light in weight, small in size, and occupies a small area. The gas volume can be steplessly adjusted in the range of 30% to 100%. It is easy to multi-stage compression and throttling. It can meet the requirements of certain chemical processes and is easy to realize automation. Large-scale machines can be directly driven by economical industrial steam turbines, which has economic advantages for enterprises with waste heat steam. The disadvantages are: high noise frequency, large cooling water consumption, improper operation will cause surge.
Post time: Nov-22-2021