Air compressor single unit selection principles

I. Air Volume Selection: In the air compressor selection process, we must meticulously consider several key factors, especially the air volume selection. This includes not only considering fluctuations in air consumption, daytime and nighttime distribution, and maximum and minimum air volumes, but also pipeline losses and potential future capacity expansion. Once the overall air volume is determined, a multi-unit control scheme combining fixed frequency and variable frequency drives is recommended to improve system flexibility and stability. For variable frequency drives, the frequency fluctuation range after constant pressure should be carefully considered, ideally between 60-100%, to ensure both efficiency and regulation capabilities.

II. Pressure Selection: When selecting air compressor pressure, it is recommended to follow the principle of separating high and low pressure lines. Specifically, for lower pressure requirements, such as 5 bar, a low-pressure pipeline should be used; while for higher pressure requirements, such as 8 bar, a normal pressure pipeline should be selected. This pressure-differentiated air supply approach effectively avoids energy waste caused by secondary "pressurization" and "depressurization" at the air consumption terminal. While most users currently prefer a general-purpose air compressor with a pressure range of 6-8 bar, both over-compression and under-compression machines lead to additional energy consumption, making it difficult for the unit to achieve ideal energy-saving performance.

III. Start-up Method Selection: Market hype has made variable frequency screw compressors a popular choice; however, this herd mentality is not advisable. Just like a car, optimal energy efficiency is achieved only within a suitable idling range. Frequent starts and stops and prolonged idling consume more fuel. For air compressors, fixed frequency screw compressors have advantages due to their high load rates, while variable frequency screw compressors ensure the compressor operates at its optimal state under constant pressure and appropriate frequency.Therefore, when selecting a compressor, we recommend using multiple units with both fixed frequency and variable frequency options, and implementing multi-unit control to ensure efficient and stable operation of the air compressor system and avoid unnecessary energy waste.

IV. Control Method Selection: Common compressor control methods include on/off, loading/unloading, throttling control, variable speed control, and multi-compressor control. Users can choose the appropriate control method according to their actual needs, and can even customize specific models. A reasonable selection of control method can effectively control no-load losses and differential pressure losses, which are particularly significant under high unloading rates and pressures exceeding operating limits.