1. Screw compressor
Screw compressors are also called screw compressors. In the 1950s, oil-injected screw compressors were used in refrigeration devices.
Because of its simple structure and few wearing parts, it can have a low exhaust temperature under a large pressure difference or pressure ratio, and it is not sensitive to a large amount of lubricating oil in the refrigerant (often called a wet stroke), and it is good. The adjustability of air delivery quickly occupied the scope of use of large-capacity reciprocating compressors, and it continued to extend to the medium-capacity range and was widely used in refrigeration equipment such as refrigeration, refrigeration, air conditioning, and chemical processes.
The screw heat pump with it as the main engine has been used in heating and air conditioning since the early 1970s. There are air heat source type, water heat pump type, heat recovery type, ice storage type, and so on. In industry, in order to save energy, screw heat pumps are also used for heat recovery.
2. Centrifugal compressor
A Centrifugal compressor is a kind of vane rotary compressor (that is, a turbo compressor). In centrifugal compressors, high-speed rotating
The centrifugal force given to the gas by the impeller and the diffuser effect given to the gas in the diffuser channel increase the gas pressure.
In the early days, because this kind of compressor was only suitable for low, medium force, and large flow occasions, it was not noticed by people. Due to the chemical industry
With the development of various large-scale chemical plants and the establishment of oil refineries, centrifugal compressors have become the key machines for compressing and transporting various gases in chemical production, and occupy an extremely important position. With the achievements of aerodynamics research, the efficiency of centrifugal compressors has been continuously improved, and key technologies such as high-pressure sealing, small flow, and narrow impeller processing, and multi-oil wedge bearings have been successfully developed. A series of problems in the development of flow range has greatly expanded the application range of centrifugal compressors so that reciprocating compressors can be replaced on many occasions, and the application range has been greatly expanded.
3. Reciprocating piston compressor
It is one of the earliest developed types of compressors. The wooden bellows invented by China in 1500 BC are the embryos of reciprocating piston compressors.
type. At the end of the 18th century, Britain made the first industrial reciprocating piston air compressor. Labyrinth compressors began to appear in the 1930s, followed by various oil-free compressors and diaphragm compressors. The counter-acting structure that appeared in the 1950s greatly reduced the size of the large-scale reciprocating piston compressor and realized multiple uses of a single machine.
Piston compressors have a long history of use and are currently the most used compressors in China. Has a wide range of forces and can adapt
Wide energy range, high speed, multi-cylinder, adjustable energy, high thermal efficiency, suitable for a variety of working conditions, etc.; its disadvantages are complex structure, many vulnerable parts, short maintenance cycle, sensitivity to wet stroke, pulse Vibration, poor running stability.
The screw compressor is a new type of compression device, which is compared with reciprocating type:
advantage:
①The machine is compact in structure, small in size, small in area, and light in weight.
②High thermal efficiency, fewer machining parts, and the total number of compressor parts are only 1/10 of the piston type. The machine has few wearing parts and can run safely
Rely on, simple operation and maintenance.
③The gas has no pulsation, the operation is stable, and the base of the unit is not high, and no special foundation is needed.
The gas 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 a slide valve, and 10~100% stepless cooling capacity can be adjusted.
Disadvantages:
Requires complex oil treatment equipment, oil separators, and oil coolers with good separation effects are required, and the noise is relatively large.
Above 85 decibels, 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, and continuous working time.
Long, small vibration, stable operation, low requirements on the foundation, when the air volume, the unit power unit is light in weight, small in size, and covers an area
Less, the gas volume can be steplessly adjusted in the range of 30% to 100%, easy to multi-stage compression and throttling, can meet the requirements of certain chemical processes, easy to realize automation, and for mainframes, more economical industries can be used The direct drive of the steam turbine has economic advantages for enterprises with waste heat steam. The disadvantages are: high noise frequency, large cooling water consumption, improper operation will produce surge.
