SU911477A2 - Device for regulating liquid flow rate - Google Patents

Description

(54) CONSTRUCTION FOR REGULATION OF FLOW RATE

I

The proposed device relates to devices for controlling the flow rate of the current medium and. can be used in various industries.

According to the main auth. No. 769500, a device for regulating a fluid flow is known, comprising in series, connected a pulse generator, a reference unit and a pulse counter, as well as series-connected control signal generator and an actuator, as well as a memory unit and series-connected synchronizer, first delay element and second element delay, the first input of the synchronizer is connected to the output of the flow meter, and the second input is connected to the output of the pulse generator, the output of the first delay element is connected to the first input m of the memory unit, the second input of which is connected to the output of the pulse counter and to the second input of the task unit, and the output to the input of the control signal generator, the output of the second delay element

connected to the second input of the pulse counter 1.

In order to ensure high accuracy of flow control and take into account the individual characteristics of the flow meter, the output frequency of the task unit of this device should be directly proportional to the installation of the required flow and inversely proportional to the calibration coefficient of the flow meter. Taking into account the scaling calibration coefficient of the flow meter makes it very difficult to build a task block while maintaining high demands on its accuracy.

This device has insufficient accuracy.

The purpose of the invention is to improve the accuracy of controlling the flow of fluid. :

Claims (1)

The goal is achieved by the fact that in the device the task block is made in the form of a serially connected first frequency divider, an additional pulse counter, a multiplier and an AND element, as well as a second frequency divider, with the second 391 input of the AND element connected to the second input of the task block and the output with the input of the task block, the input of the second splitter is often connected to: the output of the multiplier, the output - to the second input of the additional pulse counter, and the input of the first frequency splitter is connected to the second input of the multiplier and the first input th block specifying The drawing is a block diagram of a device for controlling fluid flow. The device contains a generator of 1 pulses connected in series by means of -. The pipeline 2, flow meter Hey executive body 4, task block 5, which consists of an additional counter 6 pulses, multiplier 7, first divider frequency 8, second divider 9 element frequency 10. And the device also contains a pulse counter I., memory block 12 ty and driver 13 of the control signal, the synchronizer 14, the first and second elements 15 and 16 of the delay. The P-16 units constitute the comparison unit 17. The device operates as follows. The flow control loop of the block 17, the flow meter 3 and the executive body 4 operates on the principle of negative feedback. The unit H is phased in such a way that when the reference frequency (input frequency of counter 11) increases, the controlling actuator 4 increases the signal, increasing the flow rate through pipe 2 and thereby increasing the frequency of testing (the output frequency of the flow meter 3 In the opposite situation, controlling by the executive body 4, the signal is reduced, and the frequency of testing is also reduced. When equality of the input frequency of block 17 is reached, by gcc io by 2 (where η is the counter size L) the frequency of testing, consumption the liquid through pipe 2 corresponds to the specified value. The cross on the second input of the front end is a reference, and the signal from the output of the counter 11, which is fed to the second input of the task block, is necessary to prevent it from repeating (full overflow of the sequential counter P. After the first overflow the output signal most of the time, the flow of pulses to the input of the pulse counter I is stopped. Block 5 is the driver for this control loop and determines the flow rate. This block, consisting of a differential reversible pulse counter 7, multiplier 8 and motor 9, which is scaling frequency, forms an astatic tracking circuit, the output frequency (input for block 17) of which is uniform and at the end of this transient circuit is equal to pulses from generator 1, multiplied by the division factor of the scaling divider 9 and divided by the division factor of the divider frequency 8, is the master driver. When used as a scaling and setting divider 9 and 8 decadal frequency dividers, in which the frequency multipliers are values less than or equal to 1 and vary according to a decimal law depending on the settings made on them, the frequency signal arriving to the input of the counter 11. with convenient input of the scale and the task in decimal form. The scaling calibration factor is a constant value, and a task charter is usually also constant or slowly varying in time. Therefore, since there are no high requirements for the speed of the above-mentioned astatic tracking circuit, a high bit of differential step 6 can be selected. This will ensure high accuracy of working out the frequency signal fed to the input of counter 11. Moreover, since the device uses digital logic elements, the stability work will match the characteristics of the digital device. The use of the invention will allow to obtain the required control accuracy, since this execution of the task block provides the output frequency of the task block directly proportional to the setpoint of the required flow and inversely proportional to the calibration coefficient of the flow meter. Claims of the Invention A device for regulating a liquid liquid flow according to the author. -N 769500, characterized in that, in order to increase the accuracy of the device, the task unit is made in the form of a first frequency divider, an additional pulse counter, a multiplier and an And element, as well as a second frequency divider, the second input of the And element connected to the second input of the task block, and the output with the output of the task block; the input of the second frequency divider is connected to the output of the multiplier. Bbfxofl - to the second input of an additional pulse counter; the input of the first frequency divider is connected to the second input of the multiplier and the first input of the reference block. 9114776 Sources of information taken into account with experts 1. USSR certificate If 769500 USSR, cl. G 06 D 7/00, 1978.