How to convert air compressor power according to equipment air consumption
When converting the air compressor power according to the air consumption of the equipment, the following steps and basis can be followed for calculation:
1. Core conversion formula
According to industry standards, the conversion between air compressor power and displacement follows the empirical formula:
Each cubic meter of exhaust requires 5.5 to 6 kilowatts of power。Namely:
power (kW）=Exhaust volume (m3）×5.5∼6
example: If the total air consumption of the equipment is 8 cubic meters/minute, the required air compressor power range is:
8m3×5.5kW/m3=44kW
8m3×6kW/m3=48kW
Therefore,8 cubic meters of displacement corresponds to a power range of 44-48 kilowattsIn practical applications, mainstream brands usually use 45 kilowatt motors.
2. Conversion basis and precautions
- specific power indicator：
Specific power (total power/displacement) is the core indicator for evaluating the energy efficiency of air compressors. According to the above calculation, the specific power of a 45-kilowatt motor driving an 8 cubic meter air compressor is:45kW÷8m3=5.625kW/m3
This value is in line with industry recommendationsThe specific power should be controlled at around 5.625kW/m³The standard indicates that the equipment energy efficiency meets the standards.
- scope of application：
The above conversion criteria apply toPower frequency air compressor。If a frequency conversion model is used, energy conservation can be achieved by adjusting the speed, and the actual energy consumption can be reduced by 10%-30%. - Equipment selection principles：
- Avoid overpower: If the specific power exceeds 7kW/m³, it means that the equipment is less efficient and needs to be considered replacing a more energy-efficient model.
- Reserve redundancy: In order to cope with peak demand, it is recommended to select a power slightly higher than the calculated value (if the calculated value is 44kW, a 45kW or 50kW model can be selected).
3. Actual selection steps
- Statistical equipment gas consumption：
Summarize the rated air consumption of all pneumatic tools (unit: m³/min), and consider the simultaneous use factor (usually 0.7-0.9). For example:- Pneumatic tool A: 2m³/min
- Pneumatic tool B: 1.5m³/min
- Simultaneous use factor: 0.8
- Total air consumption:(2+1.5)×0.8=2.8m3/min
- Calculate the required power：
Calculated at 5.5-6 kW per cubic metre:- Minimum power:2.8m3×5.5kW/m3=15.4kW
- Maximum power:2.8m3×6kW/m3=16.8kW
You can choose during actual selection18.5 kW motor(Reserve redundancy).
- Verify specific power：
If an air compressor with a 18.5 kilowatt motor and a displacement of 3m³/min is selected, the specific power is:
18.5kW÷3m3≈6.17kW/m3
This value is close to the upper limit. It is necessary to confirm whether the equipment is a frequency conversion model or a high-efficiency model. Otherwise, it is recommended to choose a model with a larger displacement to reduce the specific power.
