Fully automatic constant pressure variable frequency gear pump control system

The entire system is based on variable frequency speed regulation and closed-loop pressure control, combined with a gear pump to form a fluid conveying unit. It relies on real-time pressure feedback to adjust the pump speed, adapt to changes in the load of the back-end pipeline, and maintain the conveying pressure within the set range. The system supports local parameter setting, operation status monitoring, and can achieve automated start stop and abnormal protection.

###Main components of the system

1. Gear pump unit: including pump body, transmission components, and variable frequency adaptive motor, as the main body of medium conveying;

2. Pressure sensing component: installed in the pump outlet pipeline, continuously collects pipeline pressure, and converts it into standard electrical signals to be sent to the control unit;

3. Variable frequency control unit: Built in PID operation module, receives pressure feedback signal, compares the set pressure output frequency command, and adjusts the motor speed;

4. Electrical supporting components: circuit breakers, contactors, wiring terminals, operation panels, status indicator lights;

5. Auxiliary signal module (optional): liquid level acquisition, temperature monitoring, remote communication interface.

###Working principle

The operator sets the target working pressure on the control panel. The pressure sensor continuously collects the actual pressure of the pipeline and sends it back to the frequency conversion unit. The controller compares the difference between the actual pressure and the set pressure, adjusts the output frequency through PID operation, and changes the speed of the motor and gear pump.

When the pipeline load increases and the pressure is low, the system increases the speed and increases the medium output; When the pipeline load decreases and the pressure is high, the system reduces the speed and decreases the medium output. Continuous cyclic regulation to maintain relatively stable pipeline pressure.

The system adopts a soft start mode to reduce startup shock and pressure fluctuations.

###Built in basic functions

The system has electrical protections such as overcurrent, overload, undervoltage, and overheating. When the pump body runs at full speed for a long time but still cannot reach the set pressure, the system can output an alarm signal to indicate problems such as increased internal clearance and pipeline leakage. Support local fault signal prompts, and some configurations can transmit alarm information externally.

According to on-site requirements, timed start stop, sleep control, and one in use one backup rotation logic can be configured.

###Media adaptation and operating conditions

The matching gear pump is suitable for liquid media that do not contain hard particles, fiber impurities, and have fluidity. The viscosity range of the medium is 5-1500mm ²/s. Not suitable for highly corrosive media, containing a large amount of solid particles, low flash point, volatile and high-risk media.

The control cabinet needs to be placed in a ventilated and dust-free environment to prevent water vapor and corrosive gases from entering electrical components.

###Installation requirements

The pressure sensor is installed in a stable position with fluid flow to reduce signal fluctuations caused by turbulence. The pipeline is equipped with a buffer structure to reduce pressure shock. The installation of the pump unit follows the general specifications for gear pumps. Before starting, the pump chamber should be filled with medium and prolonged idling is prohibited. Electrical wiring should be properly grounded, and signal and power cables should be arranged to reduce signal interference.

###Key points of daily maintenance

Regularly check whether the wiring and signal transmission of the pressure sensor are normal; Clean the dust in the cooling channel of the control cabinet; Monitor the operating temperature of the frequency converter; Check the sealing, vibration, and sound status of the gear pump.

Cut off the power and empty the pump chamber medium during long-term shutdown. Before reactivation, check the control parameters, steering, and pipeline sealing. Only after confirming that the adjustment function is normal during no-load trial operation can it be put into operation.

###Applicable scenarios

It is commonly used in process pipelines for oil transportation, chemical raw material transportation, lubrication and oil supply that require stable transportation pressure and continuous changes in backend flow rate. Compared to the solution of fixed speed combined with overflow reflux, variable frequency speed regulation can reduce the heat accumulation caused by continuous reflux of the medium.