SU1587475A1 - Device for reculation of pressure in autoclave - Google Patents

Abstract

This invention relates to automatic control of chemical process parameters. The purpose of the invention is to improve the accuracy of the device. To do this, a third and fourth adders, two amplifiers and a task correction block are introduced into the device containing the pressure sensor in the autoclave, pressure regulators, actuators, pressure controller in the autoclave and the first and second adders. 1 il.

Description

The invention relates to the field of the automatic and mathematical regulation of chemical and technological parameters, which need to be stabilized or adjusted according to a given program with the help of executive bodies that change the flow of a substance or energy that is opposite to the control parameter.

The purpose of the invention is to improve the accuracy of the device.

The drawing shows a functional diagram of a device for regulating pressure in an autoclave.

The pressure in autoclave 1 is measured by pressure sensor 2. The reference is generated by the autoclave pressure sensor 3. The device contains the first 4 and second 5 adders, the task correction block 6, consisting of the first 7 and second 8 setters of correction, pressure regulators 9 and 10, three, 11 and fourth 12 adders, including summing elements 13 and 14 and sources 15 and 16 of the reference signal, amplifiers 17 and 18, the executive body 19, installed on the medium supply line to

autoclave, the executive body 20, installed on the discharge line environment from the autoclave. The actuators 19 and 20 are opened by increasing the output signals of the respective controllers 9 and 10 (version NC). The regulator 9 performs the regulation according to the PI-law of the regulation and chooses the reverse one (with an increase in the difference between the reference and the parameter, the output of the controller increases). The controller 10 performs the regulation according to the PI-law of the regulation and is selected direct (as the difference between the parameter and the reference increases, the output of the controller increases). The values of the signals of the first 7 and second 8 correction control devices are selected from the requirements for the accuracy of pressure control in the autoclave, and the values of the output settings of the sources 15 and 16 of the reference signal, respectively, entering the third 11 and fourth 12 adders, are selected from the requirements enforcement of the pi-law regulation and the inadmissibility of the simultaneous opening of the executive bodies 19 and 20. At the same time

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It is possible to provide independent and optimal settings for PI controllers 9 and 10 in each control channel.

The device works as follows.

In the initial state, when the pressure in autoclave 1 is zero and the task generated by pressure setting 3 is zero, the inputs to the regulators 9 and 10 receive signals equal to zero, the output signals of the regulators 9 and 10 are also zero, the actuators organs 19 and 20 are closed.

When a setpoint signal appears from the pressure sensor 3, which varies from zero to the setpoint value of the first correction unit 7, the output signal of the first adder .4 is zero and the output signal of the first regulator 9 is zero, the actuator 19 is closed, the output signal of the second the adder 5 is equal to the sum of the signals of the pressure setting device 3 and the second correction setting device 8, and is fed to the negative input of the second controller 10, whose output signal is zero, the actuator 20 is closed. When the signal setter 3 reaches a pressure greater than the signal of the first correction unit 7, a signal equal to their difference appears at the output of the first adder 4, the signal arrives at the input of the first regulator 9, which by pi rule starts to increase its output signal the executive unit 19 begins to open, the output signal of the second adder 5, equal to the sum of the signals of the pressure setting device 3 and the second correction setting device 8, is fed to the negative input of the second regulator 10, whose output signal is zero, the performer the first body 20 is closed. In this environment comes. the autoclave and the pressure in the autoclav is increasing. The first regulator 9 sets the pressure in the autoclave by means of the actuator 19 as specified by the difference between the signals of the pressure setting device 3 and the first correction setting device 7, which is determined by the required control accuracy. The third adder 11, complete with the first amplifier 17, serves to forcibly close the actuator 19 through the first regulator 9 as the pressure in the autoclave approaches the zone in which the actuator 20 set by

on the medium discharge line from the autoclave. The value of the pressure in the autoclave, at which forced closure of the actuator 19 is carried out, is determined by the magnitude of the signal from the source 15 integrated in the third adder 11. At a pressure of

autoclave, exceeding the value set by the second controller 10, i.e. exceeding the reference that corresponds to the sum of the signals of the pressure setting device 3 and the second correction setting device 8, the second controller 10 begins to change its output signal according to the PI law, the control unit 20 starts to open, and the control unit 19 is closed. At the same time, the medium is released from the autoclave and the pressure in the autoclave drops. According to the PI law, the second regulator 10 sets the pressure in the autoclave by means of the executive body 20, which is given by the sum of the signals of the pressure setting device 3 and 5 of the second correction setting device 8. The magnitude of the signal of the second setting unit 8 of the correction is determined by the required control accuracy. The fourth adder 12, complete with the second amplifier 18, serves to forcibly close the actuator 20 through the second regulator 10 when the pressure in the autoclave approaches the zone in which the actuator 19, installed on the autoclave . The value of the pressure in the autoclave, at which forced closing of the actuator 20 is carried out, is determined by the magnitude of the signal of the source 16, embedded 0 hioro in the fourth adder 12. Thus. In this case, the device ensures the operation of two isodromic regulators for regulating one parameter, which makes it possible to select the optimal laws of regulation and 5 settings for each of the channels, to ensure high accuracy of regulation. In addition, high profitability is ensured by reducing energy consumption during the technological process.

The output waveform of the pressure setting device 3 is selected based on the technological requirements.

The output signals of the first 7 and second 5-8 correction drivers are values that are constant in time, and are chosen based on the requirements for control accuracy.

The output signals of the first source 50 15 of the reference signal embedded in the third adder 11, and the second source 16 of the reference signal embedded in the Fourth adder 12 are values that are constant in time, and the output from the requirements of the inadmissibility of simultaneously finding is chosen. in the open state of the executive bodies 19 and 20.

The output of the first adder 4 is equal to the difference between the setpoint signal

3 pressures in the autoclave and the signal of the first setpoint adjuster 7.

The output of the second adder 5 is equal to the sum of the signals of the setpoint 3 of the pressure in the autoclave and the second setpoint 8 of the correction.

The output signals of the remaining blocks of the circuit are a function of the algebraic sum of the output signal of the first 4 or second 5 adder and pressure sensor 2 and do not have a time dependence on the signal of the pressure regulator 3 in the autoclave.

The output of the third adder 11 appears only if the signal from the pressure sensor 2 exceeds the sum of the signals from the first adder 4 and the first source 15 of the reference signal is equal to this excess. The output of the fourth adder 12 appears only if the signal from the second adder 5 exceeds the sum of the signals from the pressure sensor 2 and the second source 16 of the reference signal and is equal to this excess.

The output of the first amplifier 17 depends on the gain and the size of the output of the third adder 11. The output of the second amplifier 18 depends on the gain and the size of the output of the fourth adder 12.

Claims (1)

An apparatus for controlling pressure in an autoclave, comprising an autoclave pressure sensor connected by an output to the first inputs of the first and second pressure regulators, the outputs of which are connected to the inputs of the actuator respectively installed on the medium supply line to the autoclave and the actuator mounted on the line resetting the medium from the autoclave, the pressure setting device in the autoclave, the output of which is connected to the first inputs of the first and second adders connected by the outputs to the second inputs of the corresponding tween the first and second pressure regulator tori, characterized in that, in order to increase the accuracy of the device, it comprises a serially coupled third adder and a first amplifier connected in series the fourth adder and a second amplifier, and a device for specifying correction. the output of which is connected to the second inputs of the first and second adders, the first input of the third adder is connected to the output of the pressure sensor in the autoclave, and the second input to the output of the first adder, the first input of the fourth adder is connected to the output of the pressure sensor in the autoclave, and the second input is from the output of the second adder, and the output of the first and second amplifiers are connected to the third inputs of the first and second pressure regulators, respectively.