development history

The first developed screw compressor wasOil free screw compressorIn 1957, fuel injectionScrew air compressorIt was put into market application and in 1961, the oil injected screw refrigeration compressor and screw process compressor were successfully developed. After continuous basic theoretical research and product development experiments, and through continuous improvement of the rotor profile and successful development of specialized rotor processing equipment,screw compressorThe superior performance has been continuously utilized.

In the 1950s, there was fuel injectionscrew compressorApplied in refrigeration devices, due to its simple structure, few vulnerable parts, and ability to operate under large pressure differentials or ratios, the exhaust temperature is low, and it is insensitive to the large amount of lubricating oil contained in the refrigerant. It has good gas transmission regulation and quickly occupies a large capacityreciprocatingThe scope of use is constantly expanding towards the medium capacity range, and it is widely used in freezing and refrigeration.

Working principle

The screw compressor is composed of a pair of parallel and interlocked female and male screws, and is the most widely used type of rotary compressor. There are two types of compressors: single screw and twin-screw. The commonly referred screw compressor is the twin-screw compressor. It was first developed by H Krigar proposed it in 1878 and it was not until 1934 that the Royal Institute of Technology in Sweden A Lysholm laid the foundation for this technology and began to apply it in industry, achieving rapid development.

Compression principle of screw compressor:

Inhalation process:

When the rotor rotates, the interdental volume formed by the main and auxiliary rotors gradually expands, and this volume is only connected to the suction port, and external air is sucked into the interdental volume. When the interdental volume increases, it disconnects from the suction port and the suction ends. This is the 'intake process'.

Sealing and transportation process:

At the end of inhalation, the peaks of the main and auxiliary rotor teeth are sealed off from the casing, and the air in the interdental volume is enclosed in the enclosed cavity composed of the main and auxiliary rotors and the casing, which is called the "sealing process". The two rotors continue to rotate, and the teeth of the main and auxiliary rotors mesh with each other. The meshing surface gradually moves towards the exhaust end, and the air in the volume between the teeth is also transported to the exhaust end, which is the "conveying process". Compression and fuel injection process:

During the conveying process, as the rotor rotates, the inter tooth volume continuously decreases due to the meshing of the rotor teeth, and the volume of gas inside the inter tooth volume also decreases. The gas is compressed and the pressure increases, which is called the "compression process". At the same time of compression, lubricating oil is sprayed into the tooth groove due to pressure difference and mixed with air.

Exhaust process:

When the rotor rotates and the inter tooth volume is connected to the exhaust port of the casing, the compressed gas begins to be discharged. This process continues until the profile at the end of the teeth is fully engaged, at which point the inter tooth volume is zero and the gas is completely discharged, completing the "exhaust process".

Modern applications

Screw type air-cooled chiller unitWater cooled screw unit