SU1160363A1 - Regulator of pressure in autoclave - Google Patents

Description

The invention relates to the automatic regulation of chemical-technological parameters that 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 oppositely acting relative to the controlled parameter, and can be used to control pressure in an autoclave .

A pressure regulator in an autoclave is known, which contains a pressure sensor and a setting device connected by outputs to the inputs of the regulating unit, by the output connected to the input of a control valve installed on the gas supply line to the autoclave or on the gas flow line from it ΐ].

Such a regulator operates at one-20 time inflow and gas flow from the autoclave, which is uneconomical, because the gas leaving the autoclave is irretrievably lost.

The closest to the technical essence of the proposed technical solution is the pressure regulator in the autoclave, which contains a pressure sensor and a pressure setter connected by outputs to the inputs of the control unit 30 * connected to the first and second inputs of the first and second summing amplifiers connected outputs to the inputs of the first and second executive mechanisms, respectively, and a constant signal source connected by the output to the third input of the second summing amplifier.

All input and output signals · 45 blocks of a known regulator are unified. Express these signals in relative units. Summing amplifiers are used to coordinate the output of the regulating unit with inputs of the executive mechanisms, as well as for separate control of these mechanisms. This is achieved by the fact that the first summing amplifier works only in doubling mode 50 of the output signal of the regulating unit, and in the second: om of the summing amplifier, in addition to doubling the output signal, the signal equal to 1.0 is subtracted from the resulting sum. When 55 the output signal of the regulating unit changes from 0 to 0.5, a signal appears at the output of the first summing amplifier, varying from 0 to 1.0, and the valve of the first actuator is completely closed. At the output of the second summing amplifier, the signal does not change and remains equal to 0 in the type of that signal 1.0 is subtracted from the sum equal to twice the output signal of the regulating unit and the valve of the second actuator remains closed. When the output signal of the regulating unit changes from 0.5 to 1.0 at the output of the first summing amplifier, the signal does not change and is equal to 1.0 and the valve of the first additional mechanism remains completely closed. At the output of the second summing amplifier, a signal appears, varying from 0 to 1.0> and the valve of the second actuator is fully opened. Consequently, in a well-known regulator, separate control of the valves takes place, in which one of the valves is open and the other valve is necessarily closed. With the output signal of the regulating unit 0.5, both valves are closed at the same time £ 2].

A significant drawback of the known regulator, from the point of view of quality of regulation, is the presence (and not some zoo ^ yy values) of the output signal of the regulating unit, in which both valves are closed, which causes, due to the inertia of the control object, the self-oscillatory process, degrading the quality of regulation. In the presence of valves with different characteristics in the regulator, there is a deterioration in the quality of regulation due to the fact that it is impossible to optimally organize the joint operation of all its blocks with the existing settings through two control channels (gas inflow and outflow).

The aim of the invention is to reduce the amplitude of the self-oscillations of the regulator.

This goal is achieved by the fact that in a pressure regulator in an autoclave containing a pressure sensor, a pressure setter connected by outputs to the inputs of the regulating unit connected to the first inputs of summing amplifiers connected by the outputs to the inputs of the first and second performers respectively 1160363

mechanisms, additionally installed the first and second blocks of restriction, connected by inputs to the output of the regulating unit, and outputs to the second inputs, respectively, 5

first and second summing amplifiers.

The limiting blocks and the summing amplifiers allow pre-start settings and allow, at the appropriate settings, to allocate in the output signal of the regulating block an area in which the valves of both actuators are closed, which eliminates the influence of the inertia of the auto-pressure control process. The size of this zone is chosen based on the required quality of regulation. The effect of differences in valve characteristics on the quality of pressure control is eliminated by the corresponding settings of the limiting units and summing amplifiers.

The drawing shows a schematic diagram of the proposed regulator. 25 The circuit contains an autoclave 1, pressure sensor 2, control unit 3, pressure setpoint 4, first summing amplifier 5, first 6 and second 7 limiting blocks, second summing amplifier 8, first 9 and second 10 valves, the first 11 and second 12 engines "first 13 and second 14 actuators.

The actuator 13 (or 14) includes a valve 9

(or 10) and the executive engine 11 (or 12). .

In autoclave 1, pressure is measured by pressure sensor 2, the output signal is. The signal of which is fed to the input of the regulating unit 3, which has a pressure setting device 4, the output of the regulating unit 3 is connected with the first inputs of summing amplifiers 5, 8 and the inputs of the 6 And 7 limiting units. The outputs of restriction units 6 and 7 are connected to the second inputs of summing amplifiers 5 and 8. The outputs of summing amplifiers 5 And 8 are connected to the inputs of executive mechanisms 13 and 14, which control the gas flows during the inflow and outflow from the autoclave 1.

The regulator works as follows. 55

The pressure sensor 2 converts the overpressure into a unified output signal in the range; 0.2 35

45

40

1.0 kgf / cm ^g or 0-5, or conditionally ΟΙ, 0 (in relative units) by law

Rvmh.d K * "

where P_. ' ·. - output signal of the pressure sensor 2;

P - overpressure in the autoclave;

0ёr ^ 25 kgf / cm ^g ;

Cd is the transmission coefficient of the pressure sensor 2.

The regulating unit 3 generates at its output a unified signal, changing according to the proportional control law (P - the regulation law), in the range: 0.21.0 kgf / cm ² or 0-5 ma, or 0-1.0 conditionally (in relative units) by law

Rvyh.r. ~ (Rz.r. “P” s * a) К _р , where Р _{# Ь1Х} р is the output signal of the regulating unit 3;

О ^ Moat * p * 1 "θ"

- the reference signal from the output of the setting device 4;

0 "P _sp >1.0;

Кр - transfer coefficient of the regulating unit 3.

Restriction blocks 6 and 7 perform one-sided limitation of the corresponding input signals. Output unified signals of blocks 6 and 7 of the limit can vary in the range: 0.2 - 1.0 kgf / cm ² or 0-5 or conditionally 0 - 1.0 (in relative units) according to the law

^R YOU *. ^{P. When R} out.r * ^P 304

sr

(one)

EHL

^Ρ ϊθί ^{at Р} 6Ы * Р ^Р 30 <. '

RvYh.R. ^{PREY P} 9YH P ^P 30 * ^p vyzh.o7 (2)

^Р 507 at Ρβνκ.ρ ⁷ Р ₃ О7, where оь »Р β * ικ. from ~ output signals of blocks 6 and 7 of the limit;

0 <ΡβΜχ ο ^ Ι.θ - 0 / Rei ",

Р _{$ О6} , Р _ЗО7 ~ reference signals of blocks 6 and 7 'of limitation;

OKR " ₆ <1.0, 0 * P _5o . £ ₇ £ 1.0.

The summing amplifiers 5 and 8 carry out the summation of the input signals P _vmh p, R _{6 '} s <and ” ^p vih. ₀ 7C by the subsequent multiplication of the obtained sum by the gain. (The output signals of the summing amplifiers 5. 8

5 1160363

may vary in the range of 0.2 1.0 kgf / cm ² or 0-5 ma, or conditionally 0-1.0 (in relative units) according to the law

^p $ "(Remk.r ~ ^p eyh.e <" (3) five Ό with Rvykh.r, Re <k !one (E'vyh.r., "Zo ^p ^ Reyh.r at zo ') .1,0 at (P x _{in M. P} -P ₀₄ F ₅ 1.0. ten (four) ^p * - ( ^r out "R." ^r out. o?) K #> (5) one p when r _out ; _R 4p ₃₀ , ^p "') <% yykh.r ' ^p e ° 7> · Kvnri ^p "yykh.r ^{? r} and" m 1,0 at (P _{v4 (x} , p ~ ^r zot} θ ⁷ ' 1,0 _t 15 (6)

where P ₅ , P ₈ - output signals of summing amplifiers 5.8, 0--1.0; 0ίΡ _δ <1.0;

Ku, K _e - gains

summing amplifiers 5_ 20 and 8.

Consider the operation of the regulator under the following conditions:

P _1p = 0.6 (12.5 kgf / Cm ² ) -, K p-20;

Μί M · "5

In the initial state, the reference to the regulating unit 3 is zero, the overpressure in the autoclave 1 is zero, the output, the signal from the regulating unit 3 is zero, the output signals of blocks 6 and 7 of the limitation are zero, the output signals of summing amplifiers 5 and 8 are zero , valve 9 (VO version) on gas supply to autoclave 1 is closed, valve 10 (VZ implementation) on gas discharge from autoclave 1 is open.

The task is sent to the regulating unit 3 (P _sp = 0.6), the overpressure in the autoclave 1 is then equal to ₄ p l. .. The output signal of the regulating unit 3 starts to change from 0 to 0.1. The output signals of the 6 And 7 limitation blocks vary from 0 to 0.1, the output signals of the summing-up ₄ control amplifiers 5 and 8 are equal to zero, the valve 9 is closed, the valve 10 is open.

When the output signal of the regulating unit 3 changes from 0.10 to 0.35, the output signal of the restriction block 7 _5c is equal to a constant value of 0.10, the output signal of the restriction block 6 "changes from 0.10,

to 0.35, the output signal of the summing amplifier 5 is zero, the output 55 of the summing amplifier 8 varies from 0 to 1.0, the valve 9 is closed; valve 10 is fully closed, the pressure in the autoclave / equal to zero. ;

When changing the output signal of the regulating unit 3 from 0.35 to 0.60

the output signal of block 7 of the limit is equal to a constant value of 0.10 the output signal of limiting unit 6 varies from 0.35 to 0.60, the output signal of summing amplifier 5 is zero, the output signal of summing amplifier 8 is 1.0, valve 9 is closed, valve 10 is closed. The pressure in the autoclave 1 is still zero.

When the output signal of the regulating unit 3 changes from 0.60 to 0.85, the output signal of limiting unit 7 is equal to 0.10, the output signal of limiting unit 6 is equal to constant value of 0.60, the output signal of summing amplifier '5 changes from 0 to 1, 0, the output signal of the summing amplifier 8 is zero, the valve 9 opens completely and the gas begins to flow into the autoclave 1, the valve 10 is closed. Overpressure in the autoclave 1 · begins to increase.

When the output signal of the regulating unit 3 changes from 0.85 to ί., 00, the output signal of limiting unit 7 is equal to 0.10, the output signal of limiting unit 6 is equal to 0.60, the output signal of summing amplifier 5 is equal to 1.0, the output signal summing amplifier 8 is 1.0; the valve 9 is open, the valve 10 is closed, the gas enters the autoclave 1. The excess pressure in the autoclave 1 increases.

As the overpressure in the autoclave 1 approaches the K-set value (P $ _p = 0.6) from below, the output signal of the regulating unit 3 begins to change from 1.0 to 0. At the same time, the output signal of the limitation unit 7 is equal to 0.10, the output. the signal of limiting unit 6 is equal to 0.60, the output signal of summing amplifier 5 varies from 1.0 to 0, the output signal of summing amplifier 8 remains greater than 1.0, valve 9 is closed, stopping the flow of gas into the autoclave,. valve 10 is closed. The overpressure in the autoclave 1 is equal to that set at the output signal of the regulating unit 3, varying in the range of 0.60-0.35 and closed valves 9, 10.

7 1160363 '8

If the autoclave 1 has already achieved equality between the overpressure and the reference and at the same time reduces the value of the reference to the regulating unit 3, then its output signal 5 starts to decrease from 0.6 to O. The output signal of the limiting unit 7 for some time is 0.10, and then reduced to zero, the output signal of block 6 limits varies from 0.6 to 0; The output signal of summing amplifier 5 becomes zero, the output signal of summing amplifier 8 changes from 1.0 to 0, valve 9 closes, valve 10 opens 15 completely. The overpressure in autoclave 1 begins to decrease.

As the overpressure in the autoclave 1 approaches the set value from above, the output signal of the regulating unit 3 starts to change from 0 to 0.35. In this case, the output signal of limiting unit 7 becomes equal to 0, * 10, the output signal of limiting unit 6 varies from 0 to 0.35, the output signal of summing amplifier 5 is zero, the output signal of summing amplifier 8 varies from 0 to 1, 0, valve 9 is closed, valve 10 is closed completely. The overpressure in the autoclave 1 is equal to that set at the output signal of the regulating unit 3 | varying in the range of 0.35-0.60, and closed valves 9 and 10.. ₃₅

Consequently, improving the quality of the overpressure in the autoclave 1 regulation associated with eliminating Niemi aB tocol-oscillations at re gulirovamii, is achieved by creating in the output signals ₄₀ You are a regulating unit 3 zones (0.35-0.60) in which both valves 9 and 10 are closed, which ensures a smooth transition from the gas supply to its discharge from the autoclave 1. The indicated zone (0.35-0.60) in the output signal of the regulating unit 3 corresponds to the equality of the excess

pressure in the autoclave 1 set.

In the well-known regulator there is no such zone. There, the overpressure equality in autoclave 1 corresponds to a given point <0.5 in the output signal of the regulating unit, which prevents a smooth transition from supplying gas to its discharge from the autoclave and contributes to the occurrence of the auto-oscillatory process during regulation. Reducing the influence of valve characteristics on the quality of regulation is achieved not only by adjusting the regulating unit 3, but also by _{adjusting the} value of P _o , P _3o7 , K 5,

K 8.

The proposed regulator can be used to control a group of valves, for which it includes the required number of summing amplifiers and limiting blocks. As a rule, the number of summing amplifiers and limiting blocks is equal to the number of actuators. It is permissible to use one limiting unit, the output of which is connected to two or more summing amplifiers. The magnitudes of the maximum output signals of the limiting blocks are determined from the requirement to create an optimal control system.

The regulator can be implemented on domestic instruments of the Start air system: pressure sensor 2 — MS-P device; regulating unit 3 — PR2.8 regulator; unit 4 — pressure regulator RD-F.or pneumatic unit, P31.ZA, summing amplifiers 5.8 - regulators PR 2.8, restriction blocks 6 and 7 - devices for limiting signals PP11.ί or pressure reducers RD-F.

These distinctive features of the proposed technical solution. allow you to reduce the amplitude of self-oscillations of the regulator to almost zero.

Claims (1)

AUTOCLAVE PRESSURE REGULATOR, containing pressure sensor and a pressure setter connected by outputs to the inputs of the regulating unit connected by an output to the first inputs of the first and second summing amplifiers connected by the outputs to the inputs of the first and second actuators, respectively, characterized in that, in order to reduce the amplitude of the controller autocodes, the first and second limiting units are installed, connected by inputs to the output of the regulating unit, and outputs to the second inputs of the first and second summing amplifiers, respectively. 35 about WITH 35 WITH one . 1160363 2