Will the air volume increase when the working pressure of the variable frequency screw air compressor becomes lower?

Official explanation on the relationship between working pressure and gas production of variable frequency screw air compressor

In the operating characteristics of variable frequency screw air compressors, there is a dynamic correlation between working pressure and gas production. When the set pressure value of the equipment decreases, the system air supply volume will change accordingly under specific working conditions. The technical principle can be professionally interpreted from the following perspectives:

1. Analysis of frequency conversion adjustment mechanism
The variable frequency screw air compressor adjusts the motor speed in real time through a frequency converter to achieve accurate matching of the exhaust volume and the air demand. When the demand for terminal gas equipment decreases, the system pressure gradually increases, and the frequency converter automatically reduces the motor speed, reducing the work done by the main engine compression unit, thereby reducing energy consumption while maintaining pressure stability.

2. Pressure-flow characteristic curve
According to the working characteristics of the air compressor, under the same speed conditions, the exhaust pressure and the exhaust volume are inversely proportional. When the set pressure value decreases, the theoretical exhaust volume increases accordingly under the ideal state where the motor speed remains constant. However, the core advantage of the frequency conversion system lies in the dynamic balance of pressure and flow through speed adjustment. In actual operation, a comprehensive analysis needs to be carried out based on the demand of the gas end.

3. Factors influencing actual working conditions

1. Change in volumetric efficiency: When the working pressure decreases, the air density decreases and the intake volume of the main engine increases. However, it should be noted that too low pressure may lead to increased leakage and affect the actual gas production efficiency.
2. Frequency conversion response characteristics: When the pressure setting point is lowered, the frequency converter will increase the motor speed to maintain pressure stability. There is an adjustment delay of 0.5-2 seconds in this process. The buffering effect of system inertia on flow changes needs to be considered.
3. Influence of pipe network resistance: Pressure reduction may change the flow characteristics of gas transmission pipelines. It is necessary to check whether the pipe diameter meets the flow requirements after expansion to avoid gas supply bottlenecks.

4. Suggestions for energy-saving operation

1. Pressure band optimization: It is recommended to set the working pressure within a reasonable range (usually 5-7bar) according to the needs of gas equipment to avoid fluctuations in energy consumption caused by frequent adjustments.
2. Intelligent joint control configuration: It is recommended to install a flow sensor and pressure linkage device to achieve coordinated control between the frequency conversion system and the air tank and improve the system response accuracy.
3. Regular energy efficiency testing: Conduct pressure-flow characteristic testing every quarter, draw actual operating curves, and provide data support for optimizing pressure settings.

When adjusting the pressure parameters of variable frequency screw air compressors, enterprises should combine the actual production needs and use professional instruments to detect key operating parameters to avoid blindly lowering the pressure leading to insufficient gas supply or waste of energy. It is recommended to establish an equipment operation database to track the change rules of pressure, flow, power and other parameters for a long time to provide a scientific basis for formulating optimal operation strategies.