SU1330074A1 - Apparatus for automatic control of distribution of load between two units working in parallel - Google Patents

Abstract

The invention relates to a device for automatically controlling the distribution of the load between n devices connected in parallel, can be used in the chemical industry and improves the accuracy of the optimal distribution of loads. The device contains in parallel operating devices 1, the ports from o6nuix collectors 2 and 3, sensors 5 of the flow rates of the processed flows connected to the inputs of the common adder 15 and with the first inputs n of the controllers 4 of the flows of the processed flows. The outputs of the latter are connected to n actuators 7. Comparison unit 17 is connected to 18 tasks and to the output of common adder 15, n sensors 13 of the output parameter are connected to the inputs of averaging unit 11 via scaling units 12. The inputs n of the minimum selection block 6 are connected to the outputs of the private adders 8, and the outputs of blocks 6 are connected to the second inputs of the regulators 4. The inputs of the first division blocks 14 are connected to the output of the averaging block 11 and through the scaling blocks 12 to the sensors 13 output parameters. The inputs n of the second dividing unit 16 are connected with the output of the total sum of the array 15 and the sensors 5 of the expenses of the processed flows. 1 il. y (L with so about about 4

Description

The invention relates to devices for automatically controlling the distribution of the load between parallel-connected process devices, for example, soda ash furnaces, carbonization, absorption, and distillation columns of soda ash production and can be used in the chemical, petrochemical and food industries.

The purpose of the invention is to improve the accuracy of the optimal load distribution.

The drawing shows a diagram of the device.

The device contains parallel operating devices 1, fed from common collectors 2 and 3 of the processed material and energy flow, n controllers 4 supply of the processed flows, n sensors 5 expenses of the processed flows, b blocks of minimum selection, n actuators 7, p private adders 8 , n first multiplication blocks 9, n second multiplication blocks 10, averaging block 1, n mass scaling blocks 12, output parameter sensors 13, n first dividing blocks 14, common adder 15, second dividing blocks 16, block 17 cf no, the mud 18 jobs.

The device works as follows.

Processed and energy flows to each unit 1, respectively, from common collectors 2 and 3.

The input load of each device 1 is stabilized by the controllers 4 of the supply of the processed flows, controlling the position of the actuators 7. The inputs of the specified controllers 4 receive signals about the actual values of the expenses of the processed flows from the sensors 5 of the expenses -and signals about the given values of these expenses from private adders 8 (if the value of the specified flow rate exceeds the maximum permissible value for this device, then it is limited by the permissible value using the minimum selection blocks 6).

Signals about the target values of the processed material are generated by private adders 8 as the sum of two signals: the first is the corrected but output parameter of the processed flow rate signal coming from the first multiplying blocks 9 and the second signal of the flow correction correction from the second multiplying blocks 10.

The correction of flow rate signals in the output parameter is implemented as follows.

With the help of averaging unit 11, to the inputs of which, through the scaling units 12, signals from the sensors 13 of the output parameter are received, the average value of the scaled output pairs is calculated

0

to all working devices, equal to the quotient of dividing the sum of the scaled values of the output parameters by the number of working devices. The signal from the averaging unit 11 and the signals from the output parameter sensors 13 (the latter through the scaling units 12) are fed to the inputs of the first division blocks 14, by which (as a ratio of the above two signals)

0 expense correction factors for output parameter. The multiplication of signals on the consumption of the processed material (from the flow sensors 5) by correction factors (signals from blocks 14), carried out in the first multiplication blocks 9, determines the first component of the signal of the specified flow to the inputs of private adders 8.

The equilibrium state of the described flow correction loop in the output parameter is characterized by the equality of the scaled values of the output parameters for all working devices (in this case, they are also equal to their average value determined using the averaging block 11, and

5 correction factors calculated by blocks 4 are then equal to one). Deviation of the mass-stabilized values of the output parameters in one direction or another from their average value causes an increase or decrease in the correction coefficients calculated by blocks 14 and further leads to an increase or decrease in the tasks of the expenses of the processed stream on the devices calculated by blocks 9. This in turn causes the corresponding a change in the value of the output parameters, aimed at achieving their equality, and thus brings the system into a state of equilibrium.

The actual total load of the apparatus group is determined using a common adder 15, by summing the signals proportional to the flow rates of the processed streams per apparatus measured by the sensors 5. The deviation of the actual total load from the set value

the assistance of task zone 18 is determined by comparing the two signals at the inputs of the comparator block 17. A signal proportional to the magnitude of the deviation is fed to the second inputs of the second multiplication units 10. The first inputs of these blocks receive signals from the second division blocks 16, by means of which the cost correction factors are calculated from the total load. These coefficients are defined as the dues occupied

5 flow of the processed stream to this unit (signals from sensors 5) in the total amount of expenses for all devices (signal from total adder 15). So about

five

0

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at the same time, with equal scaled values of output parameters, the correction factors for the total load characterize (predict) the relative production capabilities of the devices. By multiplying the signals: the correction factor and the deviation of the actual total flow rate from the target, carried out in the second multiplication units, determine the second component of the signal of the specified flow rate that arrives at the inputs of the private adders 8.

The equilibrium state of the flow correction contour according to the total load is characterized by the equality of the actual and

-calculation adjusted by the output parameter of the specified costs of the processed material;

- calculation of the total consumption of the processed material per group of devices;

- determination of the deviation of the actual total consumption of the processed material from the specified value;

- calculation of correction factors for the total load;

- calculation of corrective additives to the specified costs of the processed material for the total load;

-the formation of the controlling effect of the specified totalizer costs of processing; according to the selected law of regulation, the material being slaughtered (in this case, their functioning of a group of apparatuses,

the difference calculated in comparison block 17, and, accordingly, the signals for the corrective additive of the flow, which arrive at the partial adders 8 from the second multiplication blocks 10, are equal to zero). The occurrence of mismatch jQ vanity between the values of a given and actual total load causes a change in the tasks of the costs of the processed stream to each apparatus in accordance with the magnitude of the error (signal from the comparator 17 and the correction factors for the total load (signals from the second division 16) Moreover, the magnitude of the corrective additive flow rate for each device (the output signal of the first blocks of 10 multiplication) is proportional to the product of the last two signals, i.e. it is calculated taking into account the production in Capabilities of the apparatus. Thus, the indicated mismatch is compensated, and the system again comes to equilibrium.

To suppress the high-frequency component of the processed flow rate signals occurring in the circuits: flow sensor 5 — regulator 4 — actuator 7 (for example, due to fluctuations in the density of the Q-current of the material being processed or for some other reason ), in the device, if necessary, can be additionally introduced filters installed at points a (see drawing).

thirty

equal according to the described algorithm, ensures the following conditions.

Equation of work of private adders

Q, Q / + Q / - J 1-п, (1)

where Q, is the value of the flow rate of the processed stream to the j-th unit corrected by the output parameter;

QT is the corrective additive of the flow rate of the processed stream to the j-th unit according to the total load.

Equation of operation of the first blocks of multiplication

Q) K ,, - Q ,, j iTiT, (2)

where Ki / is the value of the correction factor for the output parameter to the j-th unit.

The equation of the first blocks of division

wed

--, - The equation

1 I, p.

Asr i- Z

one

work

BUT,

Work equation

QS. Qi.

(3) averaging unit

(4) common adder

(5) block

Equation of Comparability

The device operation algorithm includes the following operations:

-measurement of output parameters for each device;

- calculation of the scaled values of output parameters for each device;

- calculation of the averaged value of the scaled output parameters taking into account all operating devices;

-determination of the correction factors for the output parameter;

-measuring the costs of processed flows for each device;

ten

equal according to the described algorithm, ensures the following conditions.

Equation of work of private adders

Q, Q / + Q / - J 1-п, (1)

where Q, is the value of the flow rate of the processed stream to the j-th unit corrected by the output parameter;

QT is the corrective additive of the flow rate of the processed stream to the j-th unit according to the total load.

Equation of operation of the first blocks of multiplication

Q) K ,, - Q ,, j iTiT, (2)

where Ki / is the value of the correction factor for the output parameter to the j-th unit.

The equation of the first blocks of division

5 Q

five

0

wed

--, - The equation

1 I, p.

Asr i- Z

one

work

BUT,

Work equation

QS. Qi.

(3) averaging unit

(4) common adder

(5) block

Equation of Comparability

AQi Qv - Qv, (6)

where AQv is the output of the comparison block, proportional to the mismatch between the given Qv and the actual Qv of the total loads.

The equation of the second division blocks

to Q

j 1, p,

(7)

where Ko, the value of the correction coefficient on the j-th unit on the total load. The equation of the second blocks of multiplication

Q К2гДру. j 1, p. (8)

Solve the system of equations (1) - (8) with respect to Aj

Ig AV

-;

9Qi

 .

Mr. Qi.

ist

, n. (9)

Sum up (9) no j from 1 to n

I5

.sJ.,

2- I-Q.

or

A

UE

Ha:

; io)

it is taken into account here that the summation over j of quantities that are not dependent on is equal to their product by n.

After conversion (10) we get

I Q, Qj Substitute (11) into (9)

(AND)

 Z-1

-, i.e. A, 2 Al, n,

(12)

n

at

i-1

From equations (11) and (12), it can be concluded that the optimal distribution conditions are performed by this device 25 scaling blocks — with output parameter sensors, and the outputs are connected to the first inputs and the first multiplication units, the second inputs of which are connected to the flow sensors of the processed flows, and the outputs are connected to the first inputs of private adders, the inputs n of the second division blocks are connected to the output of the common adder and the flow sensors being processed, the outflows, and the outputs are connected to the first inputs of the second restraint blocks, the second inputs - 1Y are connected to the output of

without errors and, therefore, 35 comparisons, and the outputs - with the second inputs are more bored with the known device. Private adders.

five

Claims (1)

Apparatus of the Invention A device for automatic control of load distribution between n parallel-connected devices, comprising n flow sensors of the process streams connected to the common totalizer inputs and the first inputs of the n process controllers of the process streams, the outputs of which are connected to the p actuators of the processed streams, block comparison, input to the task bus and to the output of the common adder, n sensors of the output parameter of the devices connected via scale blocks vanes with the inputs of the averaging unit, and n minimum selectors, the inputs of which are connected to the outputs of private adders, and the outputs with the second inputs of flow control regulators of the processed streams, characterized in that, in order to improve the accuracy of the optimal distribution of loads, it additionally contains n first division blocks, n second division blocks, n first multiplication blocks and n second multiplication blocks, while the inputs n of the first division blocks are associated with the output of the averaging block and 5 scaling blocks — with output parameter sensors, and the outputs are connected to the first inputs n of the first multiplication blocks, the second inputs of which are connected to the flow sensors of the processed streams, and the outputs — to the first inputs of private adders; the inputs of the second division blocks are connected to the output of the total adder and flow sensors of the processed,; currents, and the outputs are connected to the first inputs n of the second restraint units, the second inputs of which are connected to the output of the block 0 0 5 comparisons, and outputs - with the second inputs of private adders.