Relationship between rated suction volume and exhaust volume of air compressor
Analysis of the relationship between rated suction volume and exhaust volume of air compressor
As a gas compression equipment, an air compressor’s rated suction volume and exhaust volume are core performance parameters, and the relationship between the two is affected by its working principle and operating conditions. The following is carried out from four aspects: technical principles, theoretical relationships, actual differences and influencing factors:
1. Working principle of air compressor
The air compressor compresses the volume of gas through mechanical movements (such as piston reciprocation, screw rotation, impeller centrifugation, etc.) and increases the gas pressure. Take the screw type as an example:
- inhalation: The male and female rotors mesh to form a closed chamber, and gas enters through the air inlet.
- compression process: The rotation of the rotor reduces the volume of the chamber and compresses the gas.
- exhaust process: The compressed gas is discharged through the exhaust port to complete a working cycle.
2. Definition of rated suction volume and exhaust volume
- rated suction capacity: Under standard working conditions (such as temperature 20℃ and pressure 1atm), the volume of gas sucked in by the air compressor per unit time is usually m³/min.
- rated displacement: Under the same working conditions, the volume of compressed gas output by the air compressor per unit time (converted into suction state) reflects the gas production capacity of the equipment.
3. Theoretical relationship and practical differences
-
theoretical relationship
Under ideal loss-free conditions, the suction volume () and exhaust volume () Satisfy:
That is, the exhaust volume is equal to the intake volume minus the volume increase caused by compression and temperature rise.
- actual relationship
Due to the following factors, the actual exhaust volume is always less than the intake volume:
- leakage loss: Gas leaks through gaps such as piston rings and air valves.
- volumetric efficiency: Residual gas expands in the clearance volume and occupies the suction space.
- temperature coefficient: During the inhalation process, the gas is heated and expands, reducing the effective inhalation volume.
- pressure coefficient: Inspiratory resistance causes the actual inspiratory pressure to be lower than the rated value.
data examples: The rated suction capacity of a certain screw air compressor is 10m³/min, the actual discharge capacity is about 8.5 m ³/min, and the efficiency is about 85%.
4. Key influencing factors
| factors | Influence on the relationship between intake volume and exhaust volume |
|---|---|
| compression ratio | The higher the compression ratio, the greater the temperature rise,Increase, the proportion of exhaust volume decreases. |
| leakage control | The better the sealing, the less leakage losses,The higher the ratio. |
| cooling system | Improved cooling efficiency reduces suction temperature and reduces the effect of temperature coefficients. |
| maintenance state | Carbon deposition on the valve and wear on the piston rings will increase leakage and reduce volumetric efficiency. |
5. Engineering significance and optimization direction
- equipment selection: It is necessary to select the appropriate displacement model according to the gas demand to avoid “big horse-drawn cars” or overloading operation.
- efficiency improvement: Match load fluctuations through frequency conversion speed regulation to reduce ineffective compression; optimize the cooling system to reduce suction temperature.
- maintenance management: Regularly replace vulnerable parts such as air valves and piston rings; monitor leakage points and repair them in time.
summary: The rated suction volume of the air compressor is positively correlated but not equally correlated with the exhaust volume. The actual exhaust volume is affected by multiple efficiency losses. Reasonable type selection, optimized operation and maintenance management are the key to improving gas production efficiency.