SU1765530A1 - Centrifugal dump pressure controller - Google Patents

Abstract

SUMMARY OF THE INVENTION: The device comprises a series-connected pressure sensor in a pressure line, a pressure transducer to a monitored parameter and a comparison unit, the output of which is connected to the power amplifier of an actuating mechanism of variable hydraulic resistance in the pressure line. The correction element is connected to the actuator. The converter is designed as a pressure dispersion calculator and a mean square pressure value. The setter is made with two outputs connected to two inputs of a two-channel comparing unit, two other inputs to which are connected to the calculator, and outputs through the pulse shaping unit to the inputs of the adder, output to which is connected to a correction element. The calculator is designed as two parallel-connected circuits, one of which includes a series-connected quadrant and averager, the other is two averager, connected via an adder and a quadrant. 1 hp f-ly. 2 Il. SO with

Description

The invention relates to the field of hydraulics and can be used in the design of self-tuning pumping systems.

The aim of the invention is to improve the accuracy of regulation.

Fig. 1 is a schematic of a pressure control device for a centrifugal pump; Fig. 2 shows the dependence of the pressure dispersion on the head at various pump rotation speeds.

The device contains a setting device (not shown) and a series-connected pressure sensor 1 in the pressure line 10, an amplifier 2, a pressure transmitter into a monitored parameter and two-channel

a comparison unit 4, the output of which is connected to the amplifier 8 of the power of the variable hydraulic resistance actuator, for example, the valve 9 in the pressure line 10 of the pump 11.

The device is equipped with an adder 6, a two-channel control pulse shaping unit 5 and a correction element 7 connected to the amplifier 8 of the actuator mechanism of the valve 9, the converter being designed as a pressure dispersion calculator 3 and a mean square pressure value, the setter is made with two outputs connected to two inputs comparing

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block 4, the other two inputs of which are connected with compute /. Ltol 3, and the outputs through the pulse shaping unit 5 - with the inputs of the adder 6, the output of which is connected to the correction element 7. The calculator 3 is made in the form of two parallel-connected circuits, one of which includes series-connected quadrant and averager, and the other - two averager, connected via an adder and a quad (not shown).

The device operates as follows. The sensor 1 measures instantaneous pressure values, which are converted into electrical signals. These signals are amplified by amplifier 2 and fed to the inputs of the 1st and 11th channels of the calculator 3. In the first channel of the calculator 3, the average current pressure mp (t) is calculated, and in the second, its dispersion DP (t). With the calculator 3, the signals are respectively fed to the inputs of block 4, to which the required values of TTR and DfTp are supplied from the setpoint generator. After comparing, the difference signals, taking into account the sign, arrive at block 5, which generates signals corresponding to zero, positive and negative values of the difference signals. The values of the difference signals characterizing the average current value of pressure and its dispersion are fed to the adder 6 and to the correction element 7, which controls the operation of the valve 9 by means of the amplifier 8.

Three modes can be implemented.

1. Pressure control on line 10 of the centrifugal pump 11 according to the criterion of the minimum of the standard deviation from the specified value. By means of sensor 1, instantaneous pressure values are measured, which are converted into electrical influences. These signals are amplified by amplifier 2 and fed to the input of the 1st channel of calculator 3, where the average current pressure value mp (t) is calculated. From the calculator 3, the signals are fed to one input of block 4, and to the other input from the setpoint device the required value of the unit is supplied. After comparing, the differential signals, taking into account the sign, arrive at the first input of the block 5, which generates signals corresponding to zero, positive and negative values of the difference signals. Next, the signal enters through the adder b in the correction element 7, the amplifier 8 and the valve 9.

2. Pressure control in the discharge line of a centrifugal pump according to the criterion of the minimum dispersion of the head.

The instantaneous pressure values measured by sensor 1 and amplified by amplifier 2 are fed to the input of the I-th channel of calculator 3, where the head dispersion DP (t) is calculated.

5 With calculator 3, signals are fed to one input of block 4, and the other dispersion value DPTp is fed to the other input of it from the setting unit. After comparing, the difference signals are given the sign and the sign is determined

0, by deviations from the mean value, is fed to the second input of block 5, which generates signals corresponding to zero, positive and negative values of difference signals. Next through

5, the adder 6 signals are fed to the correction element 7, which takes into account the inertial properties of the system, for example, by means of derivatives. The signal from the correction circuit, amplified by an amplifier 8,

0 is processed by the valve 9, which changes the pressure in the line 10 of the pump 11.

3. Continuous current regulation at the same time of the average value and dispersion of the liquid head relative to the front.

5 preset values. Constantly using the sensor 1, the instantaneous pressure values are measured, they are amplified by the amplifier 2 and fed to the inputs of the 1st and 11th channels of the calculator 3. In the first block of the calculator

0 3 (1st channel) calculates the average current pressure value mp (t), and the second (11th channel) calculates its variance DP (t). With the transmitter 3, the signals are respectively fed to both inputs of block 4, and to its other inputs from

The 5 knobs are supplied with the required values of TTR and DP Tp. After comparing, the difference signals, taking into account the sign, are fed to the inputs of block 5, which generates signals corresponding to zero, positive and negative values of the difference signals. Next, the signals arrive at the adder 6 and the correction element 7, which takes into account the inertial properties, are amplified by the amplifier 8 and are executed.

5 valve 9.

Claims (2)

Claims 1. A device for controlling the pressure of a centrifugal pump injection pump, comprising a setpoint generator and a series-connected pressure sensor in a pressure line, a pressure transmitter into a monitored parameter, and a comparison unit, the output of which is connected to the power amplifier of the variable pressure hydraulic actuator, characterized in that, in order to increase the control accuracy, it is equipped with an adder, a two-channel control pulse shaping unit and corrective an element connected to the actuator, wherein the converter is made in the form of a pressure dispersion calculator, and the mean square pressure value, the setpoint controller is made with two outputs connected to two inputs of a two-channel comparison unit, and two other inputs are connected to the calculator exits through the shaping unit pulses - with the inputs of the adder, the output of which is connected to the corrective element. 2. The device according to claim 1, that is, so that the calculator is made in the form of two parallel-connected circuits, one of which includes series-connected square and p bridges, and the other two interconnects through the adder and quad. Sh / PRTR , 1 / L PI ABOUT 25 50 75 Fig2 wo