SU1021705A1 - Method of water distribution of channel area - Google Patents

Abstract

A WATER DISTRIBUTION METHOD IN THE CHANNEL AREA, including a change in the flow rate at the beginning of the section to change the level at the end of the section, characterized in that, the period of lagging is carried out intermittently by the formation of waves from the maximum level to the minimum, and the average value of the level of waves during this period is equal to the value of the level change at the end of the segment and back to it by the sign y

Description

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ig. The invention relates to agriculture, in particular to the automation of water distribution in land reclamation, and can be used in water level (flow) control systems, in open channels. There is a known method of water distribution, which includes changing the flow of water to a constant value at the beginning of the canal sections depending on the change in the consumption of their consumers and maintaining a constant (specified) flow rate at the end of the sections. This method is implemented as an automatic water regulation system. downstream water level distribution 1. The disadvantage of this method is the long restructuring time of the canal section when the consumer costs change, which leads to a large water reserve to provide consumers with the rebuilding time and increase the cost of the canal. There is also known a method of water distribution in a canal section, including a change in the consumption of a section according to a change in the level at the end of the section. The flow rate is fed to the beginning of the section at a constant rate depending on the change in the consumption of consumers in order to maintain a constant consumption at the end of the section (2). The disadvantage of this method is the increased reserve volumes of water due to the large constant supply of water for the period of running-in from the beginning to the end of the section, as well as the long restructuring time due to the need to work out disturbances at the end of the section after the time of running-in. The purpose of the invention is to reduce the reserve volume and adjustment time during a disturbance at the end of a segment due to a change in the consumption of consumers. The goal is achieved by the fact that the change in the flow rate at the beginning of the section during the run-in period is carried out intermittently by the formation of waves from the maximum level to the minimum, and the average value of the level of waves during this period is equal to the value of the level change at the end of the section and back to it. The method includes measuring the change in consumer spending; calculating the required constant change in flow rate at the beginning of the section; calculating the wave height and width, the periodicity (duty ratio) of the waves (based on a constant change) and the time to reach the changed flow rate; a change in the flow rate at the beginning of the plot for the time of the flutter by wave formation; the change in the flow rate at the beginning of the plot at the end of the time of the draw-in to the constant, previously calculated value. FIG. Figure 1 shows an example of working out a lowering of a given level at the end of a section; in fig. 2 - control system for implementing the method; in fig. 3 is a regulator circuit. An increase in the transfer rate of the flow rate change at the beginning of the section, for example, at the end of the section by the formation of waves, will result in the following advantages. In comparison with the idea of forcing, it is possible to transfer the forced flow value for the selected period, i.e. for a predetermined period, an average value equal to a constant change in consumption will be transmitted, which means that it is not necessary to restructure the operation mode of the section. The movement of an intermittent wave, as is known, does not lead to the erosion of the canal dams (it is like moving water up and down). The greatest speed of movement can be obtained (it is limited only by the height of the dry channels of the channel). The scheme includes a section of open channel 1 located between the blocking structures (not shown), equipped with electrically operated gates 2 (at the beginning of the section) and 3 (at the end of the section), with consumers in the form of pumping stations or open outlets (not shown); In section 1 there is a level 4 (flow) water sensor at the end of the section and a controller 5 that controls the actuator with electric actuator 2, element of comparisons 6, time relay 7 and 8, pulse generator 9, trigger 10, counter (binary) 11, threshold element 12, one-shot 13, limiting amplifier 14, signal inverter 15, adder 16, control device 17, keys 18-23, matching elements 24 and 25. The method of water distribution in the area is as follows. At the beginning, there is an established process of water supply to the water supply section, while the output signal of sensor 4 is compensated by the command signal Dzdzd, and there is no control signal from the output of controller 5. When the water consumption of the consumers changes, the water level at the end of the section will change, the output signal of the sensor 4 measuring the level (flow) at the end of the section, resulting in the difference between it and the reference signal Ndad will form a control signal of the regulator 5 on the electric shutter 2. Control from the controller 5 is performed by forming the control duration (impulse) and periodicity (pause) of the control of the gate with the electric actuator 2, i.e. the formation of water, and to achieve the time of reaching the first wave to the sensor 4, the controller 5 is controlled by setting the duration of the constant control, i.e. constant change in consumption. After this, the steady state process is again observed at the site.

The controller of the main unit of the system works as follows.

First, from the output of the comparison element b there is no error signal (the reference signal is equal to the output signal of sensor 4), the keys 18 and 19 are open from the output time relay 7 (it is disabled), the key 23 is closed and there are no output signals from the matching elements 25 and 24, as a result keys 20 and 21 are closed. In addition, there is no control signal from the regulator 17.

When the error signal appears from the output of the comparison element 6, a switch 18 triggers time relay 7, from which the switch 19 closes, opens the key 23 and a enable signal appears at the inputs of the matching elements 24 and 25.

The limiting amplifier 14 and the inverter 15 are proportional to the mismatch signals (but with different signs) arrive at the input of keys 20 and 21, from the output of which through the adder 16 they arrive at the input of the regulating device 17. As it is not difficult to trace, the keys 20 and 21 open alternately for a time equal to the pulse duration of the pulse generator 9 (wave formation), and then closed for the time set by time relay 8 (pause). Moreover, after passing two pulses to open the keys 20 and 21, the time relay is triggered, and the output inhibit signal appears at the inputs of the matching elements 24 and 25, and the key 22 closes, and after the pause time elapses, time relay 8 releases and is the enable signal at the inputs of the match elements 24 and

25 and the key 22 is opened. The threshold element 12 sets the trigger 10 in such a way that the first pulse corresponds to the sign of the error signal through the one-shot 13. And when the time of the first wave arrives before the sensor 4 has reached the output of the time relay 7, a prohibitory signal appears at the inputs of the coincidence elements 24 and 25, the key 19 is opened and the key 23 is closed (and this happens a little earlier than the first wave arrives so that the process of continuous control described below is possible. The error output from the output of the comparison element 6 through the keys 18 and 19 and through the adder 16 is fed to the input of the regulating device 17, from the output of which the control signal appears on the actuating the shutter with electric drive 2 to the required constant position corresponding to the changed level (flow). And after the quit time from the output of time relay 7, key 18 is closed for a short time (damping time), during which the oscillations in sensor 4 decrease. the time relay is turned off and the entire circuit is reset.

The formation of waves is also possible in such a way that the first wave will be the largest value, and the rest will be reduced in magnitude and then the average value of the changed flow will be taken for the period not between adjacent waves (as in our example), but for a longer period.

The application of the method allows to reduce the construction cost of the canal at the sites of open canals with partitioning structures by reducing reserve volumes of water.

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Claims (1)

METHOD OF WATER DISTRIBUTION AT A CHANNEL PLOT, including a change in flow rate at the beginning of a section by a change in level at the end of a section, characterized in that, in order to reduce the reserve volume and restoring time due to disturbances at the end of the section due to changes in consumer consumption, a change in flow rate at the beginning of the section the run-in period is carried out intermittently by the formation of waves from the maximum level to the minimum, and the average value of the wave level for this period is equal to the value of the level change at the end of the section and back to it in sign. A a ~~ a ~~ i R 777/7777777777777777777777777777777 of FIG. 1