JPH0130162B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pipe network end pressure control system that controls pressure from one water distribution source by obtaining output signals from end pressure detectors installed at multiple points in a water distribution pipe network. It is something.

By driving part or all of a water distribution pump group, which conventionally consists of one water distribution pump or multiple water distribution pumps connected in parallel, at variable speeds, the water distribution pressure that is supplied from the water distribution source by these water distribution pump configurations can be controlled. This method is commonly used. In such a control method, since the distribution pipe network that distributes water from the water distribution source tends to be wide-area, the demand end pressure control method, especially the estimated end pressure, is used instead of the generally adopted discharge pressure control method. Many control methods have come into use. This will be explained with reference to FIG.

Figure 1 shows the case in which the estimated terminal pressure control method was used.
This is a system diagram showing a conventional example using one water distribution pump.
2 is a water distribution pump, 2 is a water distribution motor, 3 is a speed control device that provides variable voltage and variable frequency output to an induction motor, which is an example of the water distribution motor 2, to drive variable speed, 4 is a flow rate detector, and 5 is a discharge pressure detection 6 is an estimated terminal pressure setting device, and 7 is a pressure adjustment circuit.

In other words, such a pressure control method is well known and its detailed explanation will be omitted, but in FIG. 1, the estimated end pressure is The setting signal of the output of the setting device 6 and the feedback signal of the output of the discharge pressure detector 5 are given to the pressure regulation circuit 7, and the speed control device 3 starts variable speed driving of the water distribution motor 2 after the pressure regulation circuit 7 sends out the pressure regulation signal. The feedback signal is made to match the setting signal. Here, the estimated terminal pressure setting device 6
In this example, one end point of the water distribution pipe network connected to the illustrated water supply source is selected, which usually has extremely poor conditions, and the pipe resistance at this end point is determined from the value of the pressure level including the desired water supply pressure value. It provides a setting signal level and generates a setting signal having a pattern generation curve characteristic that changes in accordance with the output of the flow rate detector 4.

In this way, according to the estimated terminal pressure control method, a pressure setting signal is provided that compensates for the pipe loss that occurs depending on the amount of water supplied from the water distribution source, and the desired water supply pressure can be achieved even at the terminal end of the water distribution pipe network. However, this is only enough to satisfy the distribution of water to one terminal point selected in advance, and the change is based on the detection level of the total water distribution amount at the water distribution source. This will give you a signal output.

Therefore, in the case of such an estimated terminal pressure control method, in practice, the set signal level depends on the actual demand condition at the terminal point, and furthermore, it depends on the water supply pressure condition at other terminal points in the water distribution pipe network. etc., are not taken into consideration at all, so it is not always possible to satisfy the water supply pressure level at each terminal point of the water distribution pipe network. Particularly in a wide-area water distribution network, it is normal that water for residential areas, commercial areas, high-rise residential areas, and industrial areas with different water supply demands are mixed. In these demand flow transition curves, that is, as a specific example, in the water usage pattern over a 24-hour day, the water usage pattern for residential area water shows an early rise that is hardly seen in the water usage pattern for commercial and industrial areas. It is known that there are extremely many pattern levels in time zones and nighttime zones.

On the other hand, for water supply systems in large cities, a method is used to optimally control the pressure at the end of the pipe network using large-scale computers; Even if it is an example of obtaining pressure, it will realize high-precision and high-class control, and it will also require advanced operational technology, and from an economical perspective, it will be limited to specific applications, making it very suitable for medium-sized cities. It cannot be adopted for water application.

In view of the above-mentioned points, the present invention easily realizes pressure control corresponding to each demand flow rate transition curve by obtaining each pressure detection signal at the end of the pipeline network directly or from a telemeter, etc. This provides a pressure control system at the end of a pipe network that can be widely adopted for water supply to medium-sized cities. The present invention will be explained below based on the drawings.

FIG. 2 and FIG. 3 are a system diagram showing the main part configuration of one embodiment of the present invention and a partial explanatory diagram showing the pressure detection method thereof, in which 51, 52, 53, 54 are terminal pressure detectors, 81, 82 , 83, 84 are multipliers, 9 is a coefficient generator, and 10 is an average value calculator. In the figure, the same reference numerals as in FIG. 1 indicate parts having the same function. Here, PE indicates a pressure feedback signal calculation section, and W ₁ , W ₂ , W ₃ , and W ₄ indicate typical terminal areas in a water distribution pipe network with different water usage patterns as described above.
Here, the end partial areas W ₁ , W ₂ , W ₃ , and W ₄ are called water for residential area, water for commercial area, and water for industrial area as each demand mode, and the water distribution status can be distinguished. , end pressure detectors 51, 52, 53, and 54 are arranged in these end portion regions, respectively, to send out pressure detection signals thereof. Furthermore, in contrast to the embodiment shown in FIG. 1, the pressure feedback signal is obtained by the discharge pressure detector 5 in FIG. 1, whereas in FIGS. , 52, 53, and 54 in that the pressure feedback signal is obtained from the pressure feedback signal calculation section PF.

That is, the pressure feedback signal calculation part PE includes end pressure detectors 51, 52, 53, and multipliers 81, 82, 83, 84 arranged in the end partial regions _W1 , _W2 , _W3 , _W4 , respectively. 54 outputs as direct pressure feedback signals A ₁ , A ₂ , A ₃ , A ₄ using a telemeter etc.
are considered as one input, and the other input is a coefficient K ₁ that changes on a time-by-time basis corresponding to the above-mentioned water usage pattern and whose average value becomes 1,
Coefficient generator 9 outputs for generating signals K ₂ , K ₃ , K ₄ are given, and multipliers 81 , 82 , 83 , 8
The average value of the four outputs is determined by the average value calculator 10. Also, this pressure feedback signal calculation part PF
The output is sent to a pressure regulating circuit 7. In this way, in this embodiment, each end pressure detector 51,
Multipliers 81 and 8 are applied to the output signals of 52, 53, and 54.
2, 83, and 84 are weighted according to the water usage pattern at the installation location of the pressure detector, and the average value output thereof is generated as a pressure feedback signal.

FIG. 4 is a system diagram showing the main part configuration of another embodiment according to the present invention, in which PS represents a pressure setting signal calculation section. In the drawings, the same reference numerals as in FIGS. 1, 2, and 3 indicate the same components. That is, in the case shown in Fig. 4, the pressure setting signal calculation part PS is
It has the same function as the pressure feedback signal calculation part PF shown in the figure, and has terminal pressure detectors 51, 52,
53, 54 and the pressure setting signal calculation section, by obtaining weighted pressure signals that are respectively coefficientized and corresponding to the demand conditions of the end portion regions W ₁ , W ₂ , W ₃ , W ₄ , and further calculate the average of them. A pressure setting signal is given to the pressure adjustment circuit 7 by value calculation, and the output of the discharge pressure detector 5 is fed back to the pressure adjustment circuit 7.

As explained above, according to the present invention, by obtaining the terminal pressure detector outputs multiplied by coefficients corresponding to the water usage pattern, a special pressure feedback signal or pressure setting signal corresponding to the terminal demand condition can be generated. It is possible to provide a method for realizing a simple pipe network terminal pressure control device as described above.

Although this explanation has been given with respect to a water distribution source configuration using one water distribution pump, the present invention can be equally applied to a pressure control system in which a plurality of water distribution pumps are connected in parallel and the number of these pumps is controlled together. Needless to say. Furthermore, without being limited to having a pressure control function using a variable speed drive pump, it is easy to change to a pressure control function using other methods such as opening and closing a discharge valve, and the present invention is also applicable to this. It is obvious that this will happen.

[Brief explanation of drawings]

Figure 1 shows the case in which the estimated terminal pressure control method was used.
System diagram showing a conventional example using a single water distribution pump, Part 2
3 and 3 are a system diagram showing the main part configuration of one embodiment according to the present invention and a partial explanatory diagram showing its pressure detection method, and FIG. 4 is a system diagram showing the main part structure of another embodiment according to the present invention. It is. 1... Water distribution pump, 3... Speed control device, 4...
...Flow rate detector, 5...Discharge pressure detector, 51,5
2, 53, 54...Terminal pressure detector, 7...Pressure adjustment circuit, PF...Pressure feedback signal calculation section, PS...
...Pressure setting signal calculation part.

Claims (1)

[Scope of Claims] 1. One or more water distribution pumps connected in parallel, a variable speed drive device that drives the water distribution pumps, and a control means that obtains a pressure signal at the end of a pipe network and performs pressure control. In addition, in a pipe network terminal pressure control method in which water is distributed to a water distribution pipe network by one water distribution source, the output values of a plurality of terminal pressure detectors installed at a plurality of points in the water distribution pipe network are The pressure feedback signal is obtained by multiplying the demand flow transition curve at the installation location of a plurality of terminal pressure detectors by a coefficient that varies depending on the time and calculating the average value of the calculated output values. Features a pipe network terminal pressure control system. 2.Equipped with one or more water distribution pumps connected in parallel, a variable speed drive device that drives the water distribution pumps, and a control means that obtains a pressure signal at the end of a pipe network and performs pressure control; In a pipe network terminal pressure control method in which water is distributed from one water distribution source to a water distribution pipe network, output values of a plurality of terminal pressure detectors installed at a plurality of points in the water distribution pipe network include the detection of the plurality of terminal pressures. A pressure setting signal is obtained by multiplying the demand flow transition curve at the location where the device is installed by a predetermined coefficient that varies depending on the time, and calculating the average value of the calculated output values, and detecting the output of the pressure setting signal and the discharge pressure. A pressure control system at the end of a pipe network, characterized in that a pressure adjustment signal is obtained by comparing the signal output of a device.