Application of the hottest Sepp frequency converte

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Application of CEP inverter in constant pressure gas supply system

Application of CEP inverter in constant pressure gas supply system

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I. advantages of constant pressure gas supply frequency conversion automatic control system

in the frequency conversion constant pressure control system, the frequency converter will automatically adjust the speed and number of air compressors in the air compressor station according to the change of instantaneous gas consumption of the pipe, so that the pipe pressure will always maintain a constant set pressure, Thus, the purpose of energy saving, consumption reduction and gas supply quality improvement of the air compressor is achieved. At the same time, the automation of the control process is realized, and the air compressor is automatically alarmed and protected against overpressure, overload, overcurrent, undervoltage, etc.

II. Working principle

generally, the air compressor station is composed of multiple air compressors, each of which is driven by a motor and controlled independently. In practice, the air compressor station is designed according to the maximum working load, so when the gas consumption is small, start one or two units, and when the gas consumption is large, start multiple units in parallel operation. Set the pipe pressure value in the system, and the system will automatically load and unload according to the lower and upper limits of the preset pressure value to meet the gas consumption. This control method of air compressor station brings many problems. The existing air compressor station control usually uses the following three methods to adjust the exhaust volume:

First: vent the excess compressed air

II: turn off the motor

III: close the suction valve to make the motor idle

the above air supply methods make it impossible to realize continuous adjustment of air supply. When the air consumption is constantly changing, the air supply pressure inevitably fluctuates greatly. Frequent start and stop are easy to cause damage to the equipment by pressing the reset key, which has a considerable impact on the electricity and air compressor

III. Effect Analysis of the original pressure control method: ⑴ venting the compressed air will cause a great waste of energy, and the compressed air will be put into the atmosphere. Δ W=P ×Δ Q ( Δ Q discharged air flow) ⑵ stop the motor and adjust the pressure. It is only used in the air compressor with small capacity. The frequent start and stop of the motor consumes a lot of energy and shortens the service life of the air compressor. ⑶ close the suction valve to regulate the pressure. Most air compressors close the suction valve to idle the motor to regulate the pressure, but the air compressor still drives the compressor during idle operation. At this time, the energy consumption accounts for about 30% - 50% of the full load operation of the air compressor. The energy consumed by the motor when starting the air compressor is a load with large moment of inertia. The power required by the motor when starting without load is roughly equivalent to 2-3 times that consumed by the full load operation, and the time is about 5-60s. When the exhaust volume is controlled by frequent starting, the electric shock is large, and the energy consumption is obvious. After using the frequency converter, harmful volatiles are generated, which can realize smooth soft start and soft stop, reduce the electric shock, and extend the service life of the equipment. Frequency conversion constant pressure control mode the baking furnace innovatively adopts the on-load baking mode, and automatically adjusts the difference between the gas transmission and the set amount through PID to keep the pressure constant. The system pressure converts the pipe pressure into an electrical signal through the pressure

transmitter and transmits it to the PID unit for comparison with the set value. According to the difference, it calculates according to the established control mode, so that the frequency converter outputs the corresponding speed to control the motor of the compressor, Make the actual pressure equal to the set pressure to achieve the purpose of constant pressure, realize the continuous regulation of gas supply, and ensure the stability of pipe pressure

IV. applicable air compressor type,

1 piston air compressor

2 screw air compressor

3 centrifugal air compressor

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