How to use two air compressors in parallel

The parallel use of two air compressors can improve system stability and efficiency through collaborative air supply. The following are specific implementation plans and precautions:

1. Core logic for parallel operation

1. Pressure linkage control
   • Pressure interval setting: For example, set the pressure of the air storage tank between 0.6-0.8MPa.
   • control strategy：
     • When the pressure is ≤0.6MPa, the main machine is started; if the pressure continues to drop to 0.55MPa, the standby machine is started.
     • When the pressure is ≥0.8MPa, the air compressor with a long running time is unloaded and stopped, and the other one maintains air supply.
2. Rotation operation mechanism
   • scheduled rotation: Automatic switch between main/standby machines every 4 hours to avoid fatigue on single equipment.
   • failover: When equipment fails during operation, the standby machine is started immediately, and the main machine is shut down after the pressure returns to the lower limit.

2. Equipment configuration and wiring

1. hardware configuration
   • pipe connection: Use pipes above DN65 in parallel to ensure that the total exhaust volume matches the gas demand (such as 8.6m³/min).
   • air storage tank: A 3m³ air tank is configured to balance pressure fluctuations, and the dryer is rear to purify the compressed air.
2. electrical control
   • communication setting: Connect to the controller through the 485 communication line and set up the master (001) and slave (002).
   • parameter configuration: The master sets the upper and lower limits of linkage pressure (such as 0.78/0.62MPa), and the slave follows the master status.

3. Implementation steps

1. single machine commissioning
   • Set the pressure limit (such as 0.8MPa) and the pressure limit (such as 0.6MPa) for each air compressor respectively.
2. network configuration
   • Connect the communication line and set the master to “Linkage Mode” and the slave to “Slave Mode”.
3. start-up operation
   • Start the host and the system loads automatically. When the pressure is insufficient, the host sends a start command to the slave; after the pressure is restored, the host chooses to stop or maintain it according to the running time.

4. Matters needing attention

1. load balancing
   • To avoid uneven load caused by pressure sensor errors, the sensor needs to be calibrated regularly (the error should be <5kPa).
2. Heat dissipation and spacing
   • The distance between the two air compressors is ≥1 meter to ensure good heat dissipation and prevent high temperature alarms.
3. maintenance plan
   • Lubricating oil is changed every 2000 hours, and pressure switches and sensors are checked monthly.
4. emergency treatment
   • In case of surge or high temperatures, immediately check the intake valve and cooling system, and manually shut down if necessary.

5. Optimization suggestions

• frequency conversion control: Select a variable frequency air compressor and automatically adjust the speed according to the air consumption, saving energy by more than 30%.
• waste heat recovery: Install a heat exchanger and use the waste heat of the air compressor to preheat boiler water or heat.
• intelligent monitoring: Deploy IoT sensors to monitor pressure, temperature, and vibration parameters in real time and warn of faults.

Through the above scheme, intelligent collaboration between the two air compressors can be realized, gas supply reliability can be improved and energy consumption can be reduced. It is recommended to conduct a pressure leak test before the first parallel connection (hold the pressure for 24 hours, and the leak rate should be <5%).