light industry

一、preface
General oilfield water injection station water injection pump flow mostly adopts the traditional source of deep well pump and the water supply to the water storage tank, the feed water pump water from the storage tank to supply water pump. Finally, by injection pump will water is injected into the formation. Most of the water injection pump motor power (110, 185KW) motor, the outlet pressure of water injection pump is usually achieved by adjusting the valve, operation personnel by observe the pressure gauge pressure at any time to adjust the valve, and the rated speed of the pump motor constant, so that for motor, large horse drawn trolley phenomenon is very serious, more water pump pipe network, the process is complex, not only a waste of energy, and increases the labor intensity of the operator. The inverter constant pressure water supply control system to realize stepless speed regulation of pump motor. According to the requirement of water injection pressure automatically adjust the operating parameters of the system, maintain constant water pressure piping in the water changes, to meet water requirements. Variable frequency speed control system is advanced and reasonable energy-saving water supply system. Practical application has been great development, with the rapid development of power electronic technology, the functions of the converter is also more and more strong, make full use of the various functions of the inverter, the application of variable frequency constant pressure water supply system has a important significance.

 

二、Application of ECF200
1, the VVVF control system by Yi Chong fly inverter as the main control device, the pressure transmitter Collection 4 ~ 20mA signal transmission to the inverter PID controller, monitoring water supply and water injection pipe network pressure to change, control the inverter output frequency, adjust the working condition of the water pump, pipe network pressure maintained at a constant pressure range. Water deep well pump motor power 5.5kw, 7.5kW inverter drive control; water injection pump motor power of 110KW (or 185KW), 132kw (or 200kW) inverter drive control, according to the requirements of different water flow and pressure, the implementation of variable frequency operation, frequency standby etc. to achieve constant pressure, the system by PID controller parameter setting, according to the frequency display, display the pressure and undervoltage timeout, pressure alarm indicator and, to maintain minimum pressure to control the system operation. In front of injection pump imported pipe line installation of a pressure transmitter to control the operation of deep well pump transducer; in water injection pump outlet pipe online to install a pressure transmitter to control the operation of the water injection pump inverter, control the size of the output frequency of the inverter, thus changing the pump rotating speed, the control to achieve the purpose of constant pressure piping. When the actual pipe network pressure is smaller than a given pressure value, rising output frequency of the inverter, motor speed, pipe network pressure began to increase; conversely, the inverter output frequency is reduced, motor speed decreases, reduce the pressure pipe network, system through the automatic adjustment, the actual pressure around the set pressure keep constant pressure piping. Variable frequency speed control system in the operation of the pump to form a closed loop control parameters, the implementation of constant pressure water supply, water injection system and maintain the balance of the system, to achieve automatic control.
In the past the water injection pump flow as well: water storage tank - feed pump injection pump. The installation of variable frequency speed control system, through the constant pressure water supply control can simplify the process as: water wells - water injection pump. This technological innovation simplifies the process, reduces operation steps and water wells of the frequent start stop, automatic water supply, can effectively inhibit the pump operation in the presence of the horses, pull the car phenomenon, both to reduce the the labor intensity of the operator, can save electric energy.
2, variable frequency speed control system schematic diagram
The whole set of equipment control system works as:
Water supply pipe network pressure through the acquisition of pressure transmitter feedback signal, and then through the A / D converter conversion module will set value and acquisition signal deviation value at the same time, through PID control are compared, PID parameter of the frequency converter according to the set, data processing, results to run the frequency rate of output. PID control module has the function of comparison and difference, the pressure of the water supply pipe network is lower than the set pressure, the frequency converter will increase the operating frequency, the opposite will be reduced.

And according to the pressure change of the speed of differential adjustment, in a negative role as an example: if the pressure in the process of rising close to the set value, the rising speed too fast, PID operation will reduce the amount of execution, thereby stabilizing the pressure. Under PID control, using a 4mA corresponds to 0mpa, 20mA corresponds to 1MPa pressure transmitter to adjust the pressure of the water supply of the deep well water pump, using a 4mA corresponds to 0mpa, 20mA corresponds to 25 MPa pressure transmitter regulating water injection pump injection pressure, set the value of through the inverter terminal (0 ~ 10V) is given. The whole system in operation, when the missing phase, under voltage, inverter fault, the lowest pressure overpressure situations, the system can be audible alarm signal, especially when the lack of phase, inverter fault, overpressure, the system will automatically shut down and send alarm signals, maintenance personnel in a timely manner and maintenance the return to normal. In addition, the inverter fault, the system can be switched to manual mode, with alternate power frequency operation, to ensure the water injection production. The soft starting function of the frequency converter reduces the impulse current when the motor starts, so as to effectively protect the equipment, the power network and the like, and prolong the service life of the equipment.
3, can be extended range: all pumps, such as injection pump, oil pump, water pump, pump, blower etc..

 

三、Concluding remarks
To sum up the application of ECF200 inverter in the oil field water injection pump in is set according to actual conditions of pipeline pressure automatic regulating pump motor speed, so that the water injection pipe network pressure at a given value, in order to maximize the energy saving power, and the system is reliable operation state, realizing the constant pressure water supply, water injection system, any change water pressure, water can make the pressure in the pipe network is kept constant, greatly improving the water quality, but also solves the problem of large motor car, horse pull operation staff of complex operation, high work intensity, during the maintenance of the converter, can still use power drag, ensure the water work, has certain advancement at present, this system is stable, the effect is obvious.