Class 0 Compressed Air Stations: Concept and Practice

In today’s industrial era, where efficiency and energy conservation are paramount, high energy efficiency compressed air stations have become a focal point. A high energy efficiency compressed air station refers to a system that achieves the highest level of energy efficiency among various energy efficiency classifications. The evaluation of energy efficiency is primarily based on overall transmission efficiency, which is the ratio of the effective energy in the compressed air output by the compressed air station to the total energy consumed in producing the compressed air. To standardise and regulate the testing, calculation, and evaluation of energy efficiency for compressed air stations, relevant departments have issued a series of guidelines, such as the “Compressed Air Station Energy Efficiency Grading Guide,” “Compressed Air Energy Efficiency Assessment,” “Compressed Air Station Energy-saving Design Guide,” and “Energy-saving Monitoring of Air Compressors and Supply Systems.”

In the field of air compressors, Class 0 represents the highest standard for oil-free compressed air, as defined by ISO 8573-1. This standard categorises contaminants in compressed air into three types: solid particles, water, and oil, and assigns corresponding grades. Class 0 is the highest grade, indicating stringent control over contaminants in the compressed air.

A high energy efficiency compressed air station achieves high efficiency and energy savings through the rational configuration of air compressors and other equipment. For example, a super-efficient smart compressed air station at a steel company has been certified as a high energy efficiency compressed air station, with an overall transmission efficiency of 59.2%, far exceeding the national standard for high energy efficiency compressed air stations. In Guangzhou, a precision and efficient compressed air station has replaced old equipment with variable-frequency screw compressors and other high-efficiency devices, optimised the system design, centralised air supply, and utilised IoT and AI for smart management, ensuring the compressed air station operates efficiently and reducing energy consumption.

To achieve Class 0 oil-free compressed air, there are currently several common methods: physical oil-free methods, technical oil-free methods, and altering the lubrication materials at the source. The application scenarios for Class 0 compressed air stations are becoming increasingly widespread, including semiconductor chip manufacturing, the pharmaceutical industry, electronic precision instrument manufacturing, laser cutting, robotics, and high-end machine tools.

The implementation of high energy efficiency Class 0 compressed air stations has yielded significant results. For example, a custom-designed digital and intelligent compressed air station by a certain energy technology company, which uses oil-free air compressors and corresponding post-processing equipment, has improved transmission efficiency by 16% through the use of technology. This station also meets the ISO 8573-1 Class 0 oil-free and clean compressed air requirements, not only reducing energy consumption for the company but also contributing to green production and reducing carbon emissions.

As more high energy efficiency Class 0 compressed air stations are successfully delivered and certified, they are gradually creating a positive “green wave” across the entire industry ecosystem, providing strong impetus for the green and low-carbon transformation of the industrial sector and the sustainable development of the industry. For example, a company in Henan Province has established the first high energy efficiency compressed air station, which not only achieves high efficiency and energy savings through the rational configuration of air compressors and other equipment but also fully utilises the residual heat from the air compressors. Each year, the recovered residual heat from the air compressors can be converted into approximately 1.3 million kWh of electricity, which is used for employee showers and office heating in winter. The remaining heat is used for freeze prevention in the mine shaft, saving a significant amount of electricity costs while reducing dependence on traditional energy sources.