The difference between screw machine power frequency and frequency conversion

The main differences between power frequency and frequency conversion of screw machine are reflected in the following aspects:

1. Operation principle and performance

1. Power frequency screw machine
   • Performance principle: The motor speed is constant, and the exhaust volume is controlled by adjusting the opening of the intake valve.
   • Performance characteristics:
     • When the gas demand changes, the motor speed remains unchanged, and the opening of the intake valve changes accordingly, which may cause certain fluctuations in the exhaust pressure.
     • When starting and stopping, the motor has a high instantaneous current, which has a significant impact on the power grid. Frequent start and stop may also affect the service life of the equipment.
     • When operating at low load, electricity is still consumed similar to that at full load, causing energy waste.
2. Frequency converter screw machine
   • Operation principle: Using the stepless speed regulation characteristics of the inverter, the controller or the PID regulator inside the inverter can achieve smooth start-up and rapid adjustment response. The motor speed is adjusted in real time according to the actual gas consumption, thereby controlling the exhaust volume.
   • Performance Features:
     • Can accurately control the system pressure, quickly adjust the response in occasions where the gas volume fluctuates greatly, and keep the air pressure stable.
     • The inverter itself covers the functions of a soft starter. The starting current is within a maximum of 1.2 times the rated current, and it has a small impact on the power grid and equipment.
     • The motor speed changes with the amount of gas used, and the speed will automatically decrease at low loads, reduce energy consumption, and have significant energy saving effects, with an average energy saving of 15% or even more.

2. Energy efficiency and energy saving

• Energy frequency screw machine: The energy efficiency is relatively low, the energy consumption is high when operating at low load, and the energy waste is obvious.
• Inverter screw machine: High energy efficiency, can automatically adjust the speed according to the load conditions, minimizing energy consumption. Especially when gas consumption is low, the speed can be automatically reduced to reduce power consumption and achieve efficient and energy saving.

3. Noise and vibration

• Power frequency screw machine: Due to the fixed motor speed and large starting impact, large noise and vibration may be generated.
• Inverter screw machine: In most operating conditions, the motor speed is lower than the rated speed, the main machine mechanical noise and wear are reduced, and the noise and vibration are relatively high.Small, providing a better working environment.

4. Adaptability to AC power supply

• Power frequency screw machine: The adaptability to AC power supply voltage is relatively poor, and voltage fluctuations may affect the stable operation of the equipment.
• Inverter screw machine: Due to the overmodulation technology adopted by the inverter, it is more adaptable to AC power supply voltage. When the voltage is slightly lower, sufficient torque can be output to drive the motor to operate; when the voltage is slightly higher, the voltage output to the motor will not be too high. Especially suitable for situations where the grid voltage is unstable.

5. Applicable scenarios and costs

• Power frequency screw machine:
  • Applicable to occasions that are sensitive to costs and have low requirements for air quality, such as some ordinary factory production lines or construction sites.
  • The manufacturing cost is relatively low, the structure is simple, and it is easy to maintain and repair.
• Frequency converter screw machine:
  • is suitable for occasions where there are high requirements for air quality and stability and large fluctuations in gas usage, such as electronic manufacturing, food processing, pharmaceutical production and other industries.
  • Manufacturing costs are relatively high, but due to its energy savings and stability, it can save a lot of energy expenditure and maintenance costs in the long run.

6. Maintenance and maintenance

• Power frequency screw machine: simple structure, easy to maintain and repair. Regular maintenance of lubricant and filter elements can ensure normal operation.
• Inverter screw machine: The structure is relatively complex, but it is usually equipped with advanced intelligent control system and fault diagnosis functions, which can detect and solve problems in a timely manner. Maintenance costs are relatively low due to its smoother operation and reduce mechanical wear and failure rates.

Summary:

There are significant differences in the operating principle, energy efficiency, noise and vibration, adaptability to AC power supply, applicable scenarios and costs, as well as maintenance and maintenance. When making a choice, you should conduct a comprehensive evaluation based on actual needs, energy saving effects, cost and benefits, and choose the most suitable type of air compressor.