SU1215082A1 - Pneumatic system for controlling two coupled parameters of object with delaying - Google Patents

Abstract

The invention relates to the field of automatic regulation and can be used to solve the problem of automatically stabilizing one parameter of an object with a delay while limiting the value of the second parameter associated with the first common control channel. The system contains: the first 1 and second 2 sensors (thermocouples), the first 3 and second 4 electropneumatic converters, the second 5 and the first 6 adders, (О С

Description

nonlinear converter 7, controller 8 and actuator 9. The system is designed to stabilize the first parameter (first 1 dat) and prevent the second parameter from exceeding a predetermined value. During normal operation of the system, the error signal adjus I215082

The first parameter at the output of block 6 is minimized, the signal from the output of block 7 is equal to zero. When the second parameter of a certain limit value is exceeded, a signal appears at the output of block 7, intensively reducing the value of the second parameter. I il

I

The invention relates to the field of automatic regulation and can be used in the tasks of automatic stabilization of one parameter of an object with a delay, while limiting the value of the second parameter associated with the first common control channel.

The purpose of the invention is to improve the accuracy of controlling the parameters of an object with a delay and limit the value of one of them at a certain level.

The drawing shows the structures on the system diagram.

The circuit contains the first 1 and second 2 sensors (thermocouples), the first 3 and second 4 electropneumatic converters, the second 5 and the first 6 C5matters, the nonlinear converter 7, the controller 8, the actuator 9. The nonlinear converter 7 implements the functions of a one-wave half-wave detector with a pre-adjustable value gain factor K.

The system works as follows.

The purpose of the system is to maintain the first parameter (temperature i) at a given level of it, a, with a strict limitation of ve "3 /

the mask of the second parameter (temperature i t gr).

The pre-first 6 and second 5 cj MMaTOpH with built-in setters, and the non-linear converter 7 are adjusted so that the output signals of the non-linear converter 7 and the first 6 adder are respectively

RT)

Рб Р, К, (Р, -Р, р)

where P, Pj are pneumatic signals proportional to the measured - temperatures i, and g 5 P - the limit value

pneumatic signal P (equivalent to i-fp limit), negative bias of the second adder.

In accordance with the switching scheme, in the case when i gr correction signal P is equal to conditional zero and the system provides automatic stabilization of the first parameter i, at a given level.

When the second parameter. out of tolerance zone {i.e. g) S pressure Pj. at the second input, the first 6 adder increases by an amount proportional to the difference ij. This is equivalent to the offset, namely, the reduction of the reference to the controller 8 by the same value, i.e. changing the equilibrium in a closed system in the direction of decreasing if and i 2 The technical advantages of the proposed system as compared with the basic object, which is the prototype system, are in improving the accuracy and improving the quality of regulation: in a known system used in installations of primary oil refining to stabilize the temperature on the control plate i, with a temperature limitation, auto-oscillations with an amplitude of about 2-3 degrees occur in the ig fraction section ig

for n; The proposed system is characterized by the absence of auto-oscillation and a decrease by about half of the range

changes in the stabilized quantity i, when the second parameter is at the upper bounds of if, due to this, the likelihood of compliance with the process regulation i trp is reduced, the losses are reduced and the yield of the target product is improved

Claims (1)

Invention Formula A pneumatic system for regulating two related parameters of an object with a lag, containing in series the first J5082 the sensor, the first electropneumatic transducer and the first adder, as well as the second sensor and a serially connected controller and actuator, which, in order to improve the accuracy of the operation, the second sensor through the additionally introduced and serially connected second 10 electropneumatic transducer, the second adder and the non-linear converter are connected to the second input of the first adder, the output of which is connected to the controller input.