JPS58195909A - Pressure controlling system of duct network end - Google Patents

Abstract

PURPOSE:To realize easily a pressure control corresponding to each demand flow rate transition curve, by obtaining each pressure detecting signal of a duct network end directly or by a telemeter, etc. CONSTITUTION:As for a pressure feedback signal operating part PF, direct pressure feedback signals A1-A4 are applied as one input by a telemeter, etc., by outputs of end pressure detectors 51-54 on which multipliers 81-84 are placed in end part areas W1-W4, respectively, an output of a coefficient generator 9 for signal-generating coefficients K1-K4 which are changed at a time unit in accordance with a used water quantity pattern, and whose mean value becomes ''1'' is provided as the other input, and also a mean value of outputs of the multipliers 81-84 is derived by a mean value operator 10.

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 control methods, 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. The braking force method has come to be widely used. This will be explained with reference to FIG.

Figure 1 is a system diagram showing a conventional example using one water distribution pump in which the estimated terminal pressure control method is used; 1 is a water distribution pump;
2 is a water distribution motor, 3 is a speed control device that applies a variable voltage and variable frequency output to an induction motor, which is an example of the water distribution motor 2, to drive the variable speed, 4 is a flow rate detector, 5 is a discharge pressure detector, and 6 is a Estimated terminal pressure setting device 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.
By obtaining signals of the discharge flow rate and discharge pressure of the discharge side, that is, the water distribution source, the setting signal of the estimated terminal pressure setting device 6 output and the return signal of the discharge pressure detector 5 output are given to the pressure adjustment circuit 7, and the pressure is adjusted. From the sending of the pressure adjustment signal by the circuit 7 to the variable speed drive of the water distribution motor 2 by the speed control device 3, the return signal becomes the setting signal. Here, the estimated end pressure setting device 6 selects one end point of the water distribution pipe network connected to the illustrated water distribution source, which normally has extremely poor conditions, and calculates the pipe resistance and desired water supply pressure at this end point. The setting signal level is given from the value of the pressure level including the value, and the setting signal having pattern generation curve characteristics that changes in accordance with the output of the flow detector 4 is generated.

In this way, according to the estimated end pressure control method, a pressure setting signal is provided that compensates for the pipe line loss that occurs depending on the amount of water supplied from the water distribution source, and the desired pressure can be achieved even at the end of the water distribution pipe network. Although it is possible to obtain water supply pressure, this is only enough to satisfy water distribution to one terminal point selected in advance, and it is not the same as the detection level of the total water distribution amount at that water distribution source. This results in a signal output that changes based on the current value.

Therefore, in the method of braking estimated terminal pressure, the set signal level is practically influenced regardless of the actual demand condition at the terminal point, and furthermore, the water supply pressure condition, etc. at other terminal points of the water distribution pipe network is affected. Since no consideration is given to water supply pressure levels at each terminal point of the water distribution pipe network, it is not always possible to satisfy the water supply pressure level at each end point of the water distribution pipe network.Especially in a wide-area water distribution pipe network, the water supply demand pattern cannot be satisfied. Normally, there is a mixture of water for different residential areas, commercial area water, high-rise residential water, and industrial area water. Furthermore, in these demand flow transition curves, or as a specific example, in the estimated usage pattern over a 24-hour day, there is almost no difference between water used in residential areas and water used in commercial areas and construction areas. It is known that pattern levels are extremely high in the early morning hours and night hours.

Is there a method of optimally controlling pressure at the end of the water distribution pipe network using large-scale electronic computers for water distribution in major cities? Even if it is just an example of obtaining the water distribution pressure at the end, 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. It cannot be adopted for water application in medium-sized cities.

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. The present invention provides a system for controlling pressure at the end of a pipe network that can be widely adopted for industrial water. The present invention will be explained below based on the drawings.

2 and 3 are system diagrams showing the main structure of one embodiment of the present invention, and partial explanatory diagrams excluding the pressure detection method, 51. 52, 53. 54 is a terminal pressure detector;
81. 82. 83. 84 is a multiplier, 9 is a coefficient generator, and 10 is an average value operator. In the figure, the same reference numerals as in FIG. 1 indicate parts having the same function. Here, PF indicates the pressure feedback signal calculation part, Wl, VM, Ws,
It is assumed that W4 represents a typical terminal area in a water distribution pipe network having different water usage patterns as described above. Here, the terminal partial region W1, **, Vws, W
4 is for each demand mode, for example, two types called water for residential area, water for commercial area, and water for industrial area, and the water distribution status can be distinguished, and the pressure detection signal is sent to each of these end partial areas. End pressure detector 51. 52.
53. 54 are arranged. Furthermore, in contrast to the present embodiment shown in FIG. 1, the pressure return signal is obtained by the discharge pressure detector 5 in FIG.
In the figure, terminal pressure detectors 51, 52, 53. 54 in that the pressure return signal is obtained from the pressure return signal calculation section PF.

That is, the pressure return signal calculation part PF includes the multiplier 81,
82. 83. 84 is the terminal partial area ■
Terminal pressure detector 51, 52.53. 54 output as a direct pressure return signal As, kg, Al, A using a telemeter etc.
4 is given as one input, and as the other input, coefficients Kl, Kl, Kl that change on a time-by-time basis corresponding to the above-mentioned water usage pattern and whose average value becomes 1.
, K4 is given a coefficient generator 9 output,
Furthermore, multipliers 81, 82. 83. The average value of the 84 outputs is determined by the average arithmetic unit 10. Further, this pressure feedback signal calculation part PF output is sent to the pressure adjustment circuit 7. Thus, in this embodiment, each terminal pressure sensor 51, 52 . 53. Multiplier 81 . 82. 83. 84, a weight is applied according to the usage water pattern at the location where the pressure detector is installed, 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, and P8 represents a pressure setting signal calculation section. 1st in the diagram
The same reference numerals as in the figures, FIGS. 2 and 3 indicate the same components. That is, in the one shown in FIG. 4, the pressure setting signal calculation section P8 has the same function as the pressure return signal calculation section PF shown in FIG. 2, and the terminal pressure detector 51.
52, 53. 54 and the pressure setting signal calculation section to obtain weighted pressure signals that are coefficients corresponding to the demand conditions of the end partial regions Wt, Wz, Ws, h4, and further calculate the average value of the pressure signals to obtain the pressure setting signal. is applied to the pressure adjustment circuit 7, 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, a special pressure feedback signal or pressure setting signal corresponding to the terminal demand condition is generated by obtaining the terminal pressure detector outputs multiplied by a coefficient corresponding to the toilet water patter pattern. Therefore, it is possible to provide a method for realizing a simple pipe network terminal pressure braking device that is designed to reduce pressure.

Although this explanation was based on a water distribution source configuration using one water distribution pump, the invention is equally applicable to a pressure control system in which several water distribution pumps are connected in parallel and the number of these pumps is controlled together. It goes without saying that it can be done. Furthermore, without being limited to having a pressure control function using a variable speed drive pump, it is easy to change to one having a pressure braking function by other methods such as opening and closing the discharge tank, and the present invention is also applicable to this. It is obvious that this will happen.

[Brief explanation of the drawing]

Fig. 1 is a system diagram showing a conventional example using l distribution pumps using the estimated terminal pressure control method, and Figs. 2 and 3 are system diagrams showing the main configuration of an embodiment according to the present invention. FIG. 4 is a system diagram showing the main structure of another embodiment of the present invention. l Water distribution pump, 311-11 speed controller, 4 flow rate detector, 5 - discharge pressure detector, 51. 52, 53
．． 54 Terminal pressure detector, 7- Pressure adjustment circuit, PF Pressure feedback signal calculation section, P8 - Pressure setting signal calculation section.

Claims (1)

[Claims] 1. One or more water distribution pumps connected in parallel;
It is equipped with a variable speed drive device for driving the water distribution pump, a control means for obtaining a pressure control signal at the end of the pipe network, and controlling the pressure at the end of the pipe network for distributing water from one water source to the water distribution pipe network. In the control method, the output values of a plurality of end pressure detectors installed at a plurality of points in the front water distribution pipe network are determined in advance based on the demand flow transition curve at the installation point of the plurality of end pressure detectors. A pressure control force formula at the end of a pipe network, characterized in that a pressure return signal is obtained by multiplying coefficients that vary depending on time and calculating the average value of the calculated output values. 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 device that performs pressure braking by obtaining a pressure signal at the end of the pipe network, and In a pipe line end pressure control method in which water is distributed to a network by one water distribution source, the output values of a plurality of end pressure detectors installed at a plurality of points in the water distribution pipe network include the plurality of end pressures. A pressure setting signal is obtained by multiplying the demand flow transition curve at the location where the detector is installed by a predetermined coefficient that varies depending on the time, and calculating the average value of the calculated output values. A pipe network end pressure control system characterized in that a pressure adjustment signal is obtained by comparing the signal output of the