To understand the current condition of a compressed air station, whether for equipment manufacturers or users themselves, we can draw parallels with the core four steps of traditional Chinese medicine, which provide an effective framework for assessment:

look forward to

Observe the utilization of existing air pressure station equipment

Air Compressors
Understand the types of air compressors—centrifugal compressors, screw compressors (oil-free/oil-injected; fixed-speed/inverter-driven; air-cooled/water-cooled), scroll compressors, etc.

Understand the core parameters of air compressors—discharge pressure, temperature. For screw compressors, focus on load/unload times; for centrifugal compressors, pay attention to current, VSD (Variable Speed Drive) settings, and venting conditions.

Dryers
Understand the types of dryers, container pressure and age, power consumption and air consumption (air consumption is often the most variable factor and should be assessed based on professional test data, not the nominal airflow rate on the nameplate), etc.

Nitrogen Generator
Nitrogen purity, flow rate, etc.

Filter

Filtration accuracy, container pressure, and age.

Air Receivers
Container volume, temperature and pressure resistance, and age, etc.

Piping
Piping layout and pipe diameter.

Gas Usage
Understand the gas consumption process and requirements.

Which processes require gas usage on-site? As shown in the diagram above, this includes processes like painting, powder coating, instrumentation, welding, and others.

The second step is to assess the requirements for compressed air in each process route:

Such as pressure, water, dust, and oil content, temperature, material, nitrogen purity, and so on.

Inquiry
Identify current gas usage issues and understand the usage patterns.

What challenges exist regarding flow, pressure, and the presence of water, oil, and dust in the current air compressor station setup? A common issue is capacity expansion, where flow and pressure become constrained. 

However, what are the station’s current annual electricity consumption and gas usage? What is the average electricity price at the plant? How is the electricity bill calculated? What are the peak and off-peak electricity rates?

Diagnosing the Gas Quality and Energy Efficiency of the Current Station

Electricity Consumption per Unit (kW/(m³/min)): The amount of electricity consumed by the compressor station for each unit volume of compressed air output (at the compressor intake condition). Depending on the type of gas usage, costs can be separately calculated for different processes, such as compressed air for refrigeration drying, adsorption drying, nitrogen, and other gas usage processes.

For example, if there are two 250kW constant-speed compressors on-site, and the site is equipped with a refrigerated dryer and a micro-heat adsorption dryer, the average flow rate at the outlet of the adsorption dryer is 55m³/min. If the average energy consumption of the main equipment in the compressor station is 530kW, the electricity consumption per unit at the station is calculated as:

Station electricity consumption per unit = 530 / 55 = 9.64 kW/(m³/min).

Building on this, by combining the average electricity price on-site, the unit electricity cost (in RMB/m³) can be further calculated.

For example, if the average electricity price is 0.8 RMB/kWh, the electricity cost for the previously mentioned compressor station would be calculated as:

9.64 kW/(m³/min) × 0.8 RMB/kWh ÷ 60 min/h = 0.13 RMB/m³.

The above refers to the peak and off-peak electricity prices for industrial use in Zhejiang Province.

(There is a significant difference between peak and off-peak rates, making load shifting highly necessary.)

In fact, more refined management requires implementing calculations based on peak, high peak, and low valley electricity usage, as well as different electricity pricing tiers. Our maintenance-oriented equipment can also utilize load-shifting control methods, maximizing electricity savings while ensuring charges are based on off-peak rates.

Conclusion
The industry is actively promoting first-level energy-efficient compressor stations.

From the perspective of equipment manufacturers, we highly welcome first-level energy-efficient compressor stations. This is an excellent way to drive out inefficient equipment, and the dryer is the core energy-saving component in this process.

From an operations and maintenance perspective, a first-level energy-efficient compressor station reflects the hardware capability of the station to save energy. However, the operating conditions and demands at the user's site are complex and variable. The evaluation of energy-efficient stations is a qualitative assessment based on short-term monitoring of energy consumption and performance. Therefore, to truly maximize energy savings and emissions reduction, it is essential to optimize the system and align it with the user's operating habits.

By integrating online system monitoring equipment, the goal is for users to consume compressed air as simply and seamlessly as using water, electricity, or natural gas. This is the direction we should strive for and the key to achieving refined management of compressor stations on-site.

RISHENG, in the field of operations and maintenance,

will leverage its strengths in collaboration with partners,

actively contribute to the low-carbon initiative,

and support energy conservation and emission reduction.

Unity | Collaboration | Advancing Together

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