SU1521839A1 - Apparatus for controlling pumping unit - Google Patents

Abstract

The invention relates to devices for controlling pumping units in various sectors of the national economy and allows for an increase in the quality of control. The device contains a comparator 1, a voltage divider 2, diodes 3 and 4, an analog switch 5, an integrator 6, a regulating resistor 7, an analog switch 8, a regulating resistor 9, an adjusting block 10, an electropump unit 11, a pressure sensor 12 mounted on the pressure tank 13, operating mode selection unit 14, sensor 15 for the presence of fluid in the discharge pipe (flow meter), normalizing amplifier 16, comparators 18 and 19, voltage divider 20, integrator 21, non-return valve 23 installed in the discharge pipeline. 1 il.

Description

The invention relates to devices for controlling pumping units in various sectors of a national economy, mainly in agriculture and the chemical industry. The aim of the invention is to improve the quality of control.

The drawing shows a device for controlling a pump unit. ; The device contains a comparator 1, voltage | 2 voltage, diodes 3 and 4, analog to | key 5, integrator 6, regulating resistor 7, adjusting the smoothness of the stop and pump unit, analog switch 8, regulating resistor 9, which regulates the start-up of the inlet pump unit, the control unit 10 (for example, the TPC frequency converter), e | electric pump unit 11, pressure sensor 12, mounted on pressure tank 13, 6 / IOK 14 operating mode selection, liquid presence sensor 15 in pressure pipe (self-flow meter), normalizing amplifier 16, which includes trimming resistor ll, comparators 18 and 19, a divider 20 for the direction, an integrator 21, which includes a resistor 22, which regulates the smooth start-up of the pumping unit as the fluid moves in the pressure pipe, and a check valve 23 installed in the pressure pipe.

I The pressure sensor 12 is made with a system of resis, i.e. turns on at one pressure and turns off at another, and may have both an analog electrical output and a contact, for example, a break contact, which closes when the pressure is lowered and opens when the pressure increases. However, in this case, "plus the power supply of the control circuit, the disconnecting contact of such a sensor is supplied to the input A of the selection unit 14 of the operation mode. In the case of using a pump unit with a water pump, instead of pressure sensors, level sensors are installed that provide a similar control function.

As the sensor 15 for the presence of fluid in the pressure pipe, a flow meter is used that has an analog electrical outlet.

The device works as follows.

The pump unit 11 is disabled, the switch of the operation mode selection unit 14 is set to position A (automatic mode). The movement of fluid in the pressure pipe (the wire is absent and at the output of sensor 1) the presence of liquid is absent. At the output of the normalizing amplifier, the 16 signal is zero. At the output of comparators 18 and 19 there is a negative polarity signal, since their non-innerrant inputs are

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0

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negative bias voltage. Analog keys 5 and 8 are open. At the output of integrators 6 and 21, the voltage is zero. When the pressure decreases in the pressure tank 13 to the RCMS, at the output of the pressure sensor 12, a positive voltage appears corresponding to "I. This voltage is applied to the inverter's inverter input.

1. Comparator 1 switches and a negative polarity voltage appears at its output. This voltage is through a divider.

2, diode 4, the open analog switch 8 and the resistor 9 are fed to the input of the integrator 6. A gradual increase in the voltage at the output of the integrator 6 begins, causing the control unit 10 to increase its output signal and the electropump unit 1 smoothly accelerates. The smoothness of the run-up of the unit is established by the trimming resistor 9. After opening the check valve 23, the fluid begins to move in the pressure pipe. At the output of the liquid presence sensor (flow meter) 15, the voltage begins to increase and a negative voltage occurs at the output of the normalizing amplifier 16, which is proportional to the velocity of the liquid in the pressure pipe. This voltage enters the converting input of the comparators 18 and 19. The comparator 18 switches and a positive polarity arises at its output, which through the voltage divider 20 enters the input of the integrator 21, which sets the required start intensity in the presence of a fluid flow in the pipeline. The required fluid flow rate is set by trimmer 22 of integrator 2i. At the output of the integrator 21, the negative polarity voltage starts to increase linearly. This voltage is fed to the input of the comparator 19 and is compared on it with the voltage coming from the normalizing amplifier 16. If the fluid supply in the pressure pipe is greater than the established one, then the voltage at the output of the normalizing amplifier 16 is higher than the voltage at the integrator 21. The comparator 19 switches and a voltage of positive polarity arises at its output. The analog switch 8 closes and the voltage rise at the output of the integrator 6 stops. The increase in the frequency of rotation of the pumping unit 1, therefore, the increase in the liquid supply in the pressure pipeline, as well as the increase in voltage at the output of the normalizing amplifier 16, stops. At the same time, the voltage growth at the output of the integrator 21 continues. As soon as the voltage at the output of the integrator 21 becomes greater than the voltage at the output of the normalizing amplifier 16, the comparator 18 switches to the voltage of negative polarity at its output, which is supplied to

analog key control input 8. The analog key 8 opens and further voltage increases at the output of integrator 6, and consequently, further acceleration of the pump unit 11. Thus, there is a smooth acceleration of the pump unit with a predetermined intensity when monitoring the flow of fluid in the discharge pipe.

When the pressure Ria-kc is reached in the tank 13, the level "O" appears at the outlet of the pressure sensor 12. Comparator 1 switches because its noninverted input has a positive bias voltage. The output of the comparator 1 produces a positive polarity voltage, which through diode 3 and the trimming resistor 7 is fed to the input of the integrator 6 (the analog switch 5 is closed at this moment, since its control input contains a positive polarity). The voltage at the output of the integrator 6 decreases, and the rotational speed of the pump unit 11 decreases. The smoothness of stopping the pump unit is determined by the trimming resistor 7. The pressure developed by the pump unit decreases, the check valve 23 closes. The movement of fluid in the pressure pipe is stopped. The voltage at the output of the sensor 15 of the presence (flow meter) of the liquid and at the output of the normalizing amplifier 16 becomes equal to zero. The comparator 18 switches and a negative polarity voltage arises at its output. The analog switch 5 opens and shunts the resistor 7. There is a rapid decrease in the output voltage of the integrator 6, as well as a decrease in the rotation frequency of the pump unit and its self-locking.

In mode P (manual control), the positive voltage to the input of comparator 1 comes from a power source (not shown) and the device operates as described.

Thus, by this device it is possible to carry out feedback on the fluid supply and control the growth

supplying fluid in the discharge pipeline during the start-up of the pump unit, which leads to an increase in the quality of control of the pump unit during the start-up.

Claims (1)

Invention Formula A device for controlling pumping units, containing a sensor for the presence of fluid in the pressure pipe, a pressure sensor installed on the pressure tank, which is connected to the input of the operating mode selection unit, the output of which is connected through the first comparator to the input of the first voltage divider, the output of which Connected to the common connection point of the anode of the first diode and the cathode of the second diode, the cathode of the first diode is connected to one of the terminals of the first regulating resistor, its moving contact and the other terminal are connected to the input of the first the integrator, to which one of the leads and the moving contact of the second regulating resistor is connected, the output of the first integrator is connected to the input of the control unit, the output of which is connected to the electric drive of the pump unit, characterized in that it is equipped with second and third comparators to improve the quality, the second voltage divider, the second integrator, the normalizing amplifier and two analog keys, and the liquid presence sensor is designed as a flow meter that is connected to the input of a normalizing amplifier whose output is connected to the input of the second and to one of the inputs of the third comparators, the output of the second comparator is connected to the input of the second voltage divider and to one of the inputs the first analog switch, the other input of which is connected to the cathode of the first diode, the output of the third comparator, is connected to one of the inputs of the second analog switch, another input of which is connected to the anode of the second diode, the output of the second analog switch is connected to another output of the second regulating resistor, the output of the second divider is connected via a second integrator to another input third comparator.