Views: 3457 Author: Site Editor Publish Time: 2025-05-06 Origin: Site
Screw air compressors are widely used in industrial production due to their compact size, low noise, and high efficiency. Understanding their key performance parameters is essential for equipment selection, operation monitoring, and energy efficiency assessment.
This article systematically explains the core performance parameters of screw air compressors.
1.1 Unit Volumetric Flow Rate
Aspect | Description |
|---|---|
Definition | Actual air flow rate at the standard discharge position, converted to standard intake conditions |
Standard Requirement | Shall not be less than 95% of nominal flow under specified conditions |
Significance | Reflects actual air delivery capacity |
1.2 Unit Power
Aspect | Description |
|---|---|
Definition | Total input power required for compressed air output |
Note | Excludes power used by integrated after-treatment equipment |
Significance | Measures energy consumption level |
1.3 Specific Power
Aspect | Description |
|---|---|
Definition | Ratio of unit power to unit volumetric flow rate |
Formula | Specific Power = Unit Power ÷ Volumetric Flow Rate |
Significance | Core efficiency indicator — lower values mean better efficiency |
1.4 No-Load Power
Aspect | Description |
|---|---|
Definition | Power when compressor head runs but flow rate is zero |
Requirement (0.7MPa) | No-load power / Unit power ≤ 35% |
Requirement (0.8MPa) | No-load power / Unit power ≤ 29% |
Special | Oil pump required when discharge pressure < 0.5MPa |
1.5 Shaft Power
Aspect | Description |
|---|---|
Definition | Power required at the compressor drive shaft |
Composition | Internal power + mechanical losses |
Note | Excludes external transmission losses (gear or belt) |
1.6 Discharge Pressure
Aspect | Description |
|---|---|
Definition | Absolute total pressure at the standard discharge position |
Note | Absolute static pressure may substitute if dynamic pressure < 0.5% of static pressure |
Under specified conditions (ambient 40°C, cooling water inlet 30°C, cooling water flow to unit power ratio ≤ 1.69 L/min·kW):
Condition | Temperature Limit |
|---|---|
Normal operation | ≤ 110°C at each stage |
Discharge pressure > 1.25MPa with synthetic oil | ≤ 130°C |
Critical Note: Before oil-air separation, the minimum compressed air temperature must not fall below its pressure dew point.
Parameter | Significance |
|---|---|
Noise dB(A) | Work environment comfort |
Discharge temperature | Cooling system effectiveness |
Speed | Affects flow and efficiency |
Oil carryover | Compressed air quality |
Oil capacity | Maintenance cost |
Outlet size | Piping compatibility |
Each screw air compressor must display a nameplate with at least:
No. | Content | Unit |
|---|---|---|
1 | Product model | — |
2 | Product name | — |
3 | Nominal volumetric flow rate | m³/min |
4 | Rated discharge pressure | MPa |
5 | Shaft power or motor power | kW |
6 | Dimensions (L×W×H) | mm |
7 | Net weight | kg |
8 | Serial number | — |
9 | Manufacturing date | — |
10 | Manufacturer name and location | — |
Parameter | Definition | Standard/Limit | Efficiency Significance |
|---|---|---|---|
Volumetric flow rate | Actual air delivery | ≥95% of nominal | Supply capacity |
Unit power | Total input power | As measured | Energy consumption |
Specific power | Power ÷ Flow | Lower = better | ⭐Core indicator |
No-load power | Power at zero flow | ≤35% / ≤29% | Standby energy |
Shaft power | Drive shaft power | As measured | Mechanical efficiency |
Discharge pressure | Outlet absolute pressure | Per design | Output capability |
Discharge temperature | Stage outlet temp | ≤110°C / ≤130°C | Cooling effectiveness |
Priority | Focus | Suggestion |
|---|---|---|
Energy savings | Specific power | Lower values indicate better efficiency |
Air demand | Volumetric flow rate | Verify meets peak production needs |
Operating cost | No-load power ratio | Affects standby energy consumption |
High-temperature environment | Discharge temperature margin | Ensure adequate cooling capacity |
Air quality | Oil carryout | Critical for sensitive applications |
Select based on actual air demand requirements, comparing parameters across manufacturers rather than pursuing any single indicator in isolation.
