Here is the translation of the explanation about the three important efficiency indicators of a screw air compressor:

Volumetric Efficiency: Volumetric Efficiency refers to the ratio between the actual air delivery and the theoretical air delivery during the compression process. The theoretical air delivery is the air flow before compression, while the actual air delivery is the amount of compressed air produced during the actual operation of the air compressor. A higher volumetric efficiency indicates that the air compressor’s actual air production capacity is closer to its theoretical air production capacity, reflecting a higher efficiency in the compression process.

Compression Efficiency: Compression Efficiency is the ratio between the actual compression work and the theoretical compression work during the compression process. The theoretical compression work is the minimum power required to compress the air to the desired pressure, while the actual compression work is the power consumed during operation. A higher compression efficiency indicates that the air compressor can achieve the desired pressure with improved energy-saving and efficiency.

Mechanical Efficiency: Mechanical Efficiency refers to the ratio between the actual power consumed by the rotating mechanical components of the screw-type air compressor and the input power. The input power is the total power supplied by the air compressor’s motor, while the actual power is the power consumed by the rotating mechanical components. A higher mechanical efficiency indicates that the air compressor’s transmission system and mechanical structure are more precise and efficient, effectively reducing energy losses.

Summary: Volumetric Efficiency, Compression Efficiency, and Mechanical Efficiency are important indicators for evaluating the performance and efficiency of a screw-type air compressor. They respectively focus on the air production capacity, compression energy consumption, and mechanical transmission efficiency.