Comparison of screw compressor and scroll compressor

There are significant differences between screw compressors and scroll compressors in many aspects, which are mainly reflected in the structure, working principle, performance characteristics and application scenarios.

structure contrast

• screw compressor: It is mainly composed of a pair of intermeshing male and female rotors (screws), which rotate in the casing to compress gas. The design of the rotor is complex, the tooth surface is a space surface, need to use special tools in expensive equipment processing, the cylinder machining accuracy also has a higher requirement.
• Scroll Compressor: The gas is compressed by a pair of intermeshing scrolls (one fixed and one rotating). The design of the scroll is relatively simple, there is no reciprocating mechanism, so the structure is compact, the number of parts is small, especially the vulnerable parts are few.

Comparison of working principle

• screw compressor: The gas is sucked, compressed and discharged in the cavity between the rotors. As the rotor rotates, the recess is closed by the casing wall to form a compression chamber, into which lubricating oil is then injected for sealing, cooling and lubricating purposes. During the compression process, the gas is continuously compressed, but the exhaust temperature is relatively low.
• Scroll Compressor: The gas is sucked in from the periphery of the scroll, and is gradually compressed and pushed to the center for discharge as the scroll rotates. The whole process of suction, compression and exhaust is carried out continuously at the same time, the pressure rise speed is slow, the torque change range is small, and the vibration and noise level are relatively low.

Comparison of performance characteristics

• screw compressor:
  • high reliability: Few parts, no wearing parts, reliable operation and long life.
  • Easy operation and maintenance: High degree of automation, operators do not need long professional training.
  • Good power balance: No unbalanced inertial force, can work smoothly and at high speed, suitable as a mobile compressor.
  • strong adaptability: Volume flow is almost not affected by exhaust pressure, suitable for a variety of working conditions.
  • high cost: The processing accuracy is high and the equipment is expensive.
  • Pressure Limits: Generally used in the middle and low pressure range, the exhaust pressure generally does not exceed 3MPa.
• Scroll Compressor:
  • simple structure: Small size, light weight, few parts, easy to realize automation.
  • Low noise no suction, exhaust valve and complex motion mechanism, extremely low noise.
  • Low energy consumption: High volumetric efficiency, high mechanical efficiency and low energy consumption.
  • Low maintenance costs: The host has fewer parts, fewer wearing parts, and low maintenance costs.
  • Compression ratio limit: Due to the limitation of the sealing gap, the compression ratio is relatively low, suitable for small and medium gas volume, medium and low pressure occasions.

Comparison of application scenarios

• screw compressor: It is widely used in large-scale industrial refrigeration equipment, air compressor stations, gas compression in the process and other fields, especially when high pressure and atmospheric volume are required.
• Scroll Compressor: It is more suitable for household appliances, commercial refrigeration equipment, small air compressors and other fields, because of its low noise, low energy consumption, easy maintenance and favored.

In summary, screw compressors and scroll compressors each have their own unique advantages and applications. When choosing, it should be considered according to specific needs, such as gas volume, pressure requirements, energy efficiency requirements, application scenarios, and maintenance costs.