What is stepless airflow control in piston compressors?
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What is stepless airflow control in piston compressors?
The indicated work consumed by the compressor is essentially proportional to the operating load. It is understood that the capacity of the bypass valve is approximately equal to the designed gas flow rate of one machine; when the opening degree of both bypass valves is 30%, if the designed gas flow rate is around 10,000 Nm3/h, the amount of gas returning is about 25% of the compressor’s designed gas flow rate. If a stepless air volume control system is added to this machine, with the compressor operating at 75% load, it can save approximately 1 million yuan in electricity costs per year ； It is evident that, even from the perspective of energy conservation alone, the economic benefits resulting from implementing a project for stepless air volume control are quite substantial.
The compressor load is automatically adjusted between 0–100% through a hydraulic actuator and a DCS control system; adjusting the compressor’s airflow is simplified to merely entering the desired pressure setpoint, with the system automatically tracking and maintaining that value. It enables smooth loading of the compressor, without shocky switching or shutdowns, ensuring stable parameters. .
It means that load adjustment is more flexible – it can be automatically adjusted between 0 and 100, as opposed to the previous options of 0, 50, and 100 – which results in better energy savings
The hydraulic actuator and specialized air valve that form the core of the stepless air volume control system. By delaying the closure of the intake valve, the excess gas returns to the intake manifold without being compressed, so only the amount of gas that needs to be compressed is compressed during the compression cycle. This is precisely the application of the so-called \"backflow energy saving\" principle. Under the control of a variable air volume control system, the compressor’s intake valve is no longer an automatic valve that operates based on pressure differences, but rather a forced valve driven by an external power source.