Ratio between air volume at air inlet and air volume
The air volume ratio between the inlet and outlet of an air compressor is an important parameter reflecting the performance of the compressor. It is affected by various factors such as compression ratio, efficiency, and leakage. The following is a detailed analysis of this ratio:
1. Theoretical ratio calculation
Under ideal conditions (assuming no leaks and no energy losses), the air volume ratio between the air inlet and outlet of the air compressor can be calculated from the compression ratio.
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Compression ratio definition: Compression ratio (ε) is the ratio of outlet pressure (absolute pressure) to inlet pressure (absolute pressure), that is:
Among them, To vent pressure, is the intake pressure.
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theoretical ratio: Under ideal circumstances, the air volume () and intake air volume () is the inverse of the compression ratio, that is:
example: If the compression ratio is 8 (i.e., the outlet pressure is 8 bar and the inlet pressure is 1 bar), the theoretical ratio is:
2. Analysis of actual ratio
In actual operation, due to factors such as leakage and energy loss, the gas volume will be less than the theoretical value, so the actual ratio will be less than the theoretical ratio.
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influencing factors：
- leakage: Leaks inside the compressor and pipes will cause the loss of some compressed gas and reduce the gas volume.
- efficiency: The efficiency of an air compressor (including volumetric efficiency and mechanical efficiency) reflects the effectiveness of its energy conversion and gas compression. The lower the efficiency, the smaller the actual ratio.
- temperature coefficient: The increase in gas temperature during compression will cause volume expansion and affect the gas volume.
- pressure coefficient: The greater the compression ratio, the more significant the decrease in outlet air volume relative to intake air volume.
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Actual ratio calculation: Considering factors such as leakage and efficiency, the actual ratio can be estimated by the following formula:
Among them, is the volume factor, is the temperature coefficient, is the pressure coefficient, is the leakage coefficient. These coefficients are all less than 1, reflecting the losses in actual operation.
III. Conclusion
The air volume ratio between the air inlet and the air outlet of an air compressor is a parameter that comprehensively reflects the performance of the compressor. Ideally, this ratio is the inverse of the compression ratio; in actual operation, due to factors such as leakage and efficiency, the actual ratio will be less than the theoretical ratio. Therefore, when selecting and using air compressors, performance parameters such as compression ratio and efficiency need to be comprehensively considered to ensure that actual needs are met.