WATER DISTRIBUTION MANAGEMENT SYSTEM
BACKGROUND OF THE INVENTION
1. Field of the Invention
[0001]
The present invention relates to a water distribution management system.
2. Description of the Related Art
[0002]
In a utility water distribution network, supply pressure of water must be configured so that every consumer can secure a sufficient water supply amount. On the other hand, since high water supply pressure tends to promote water leakage in the water distribution network, the supply pressure is desirably maintained within an appropriate range. [0003]
As a method of determining appropriate supply pressure of water in such a water distribution network, for example, techniques for performing hydraulic analysis using a model as shown in FIG. 21 are disclosed (for example, refer to WO 2015/083551). According to this technique, a balance between a water supply amount and a water leakage amount can be attained by estimating a node at which water pressure is minimized from a plurality of nodes in the water distribution network and maintaining the water pressure at the node to a necessary minimum value.
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[0004]
SUMMARY OF THE INVENTION
[0005]
However, with conventional art such as that described above, although appropriate supply pressure can be obtained under continuous water supply which enables water to be always supplied, when each consumer uses a water storage tank under intermittent water supply which, for example, only allows water to be supplied for a few hours in a day, there may be cases where appropriate supply pressure cannot be determined.
[0006]
The present invention has been made based on circumstances such as that described above and an object thereof is to provide a water distribution management system capable of determining appropriate supply pressure based on a leakage rate and a satisfaction level even in a situation where a water storage tank is used in intermittent water supply.
[0007]
The present invention relates to
(1) A water distribution management system which performs intermittent water supply from a distribution reservoir to a consumer having a water storage tank coupled to each of the nodes via a plurality of nodes in a water distribution network, the water distribution management system including: hydraulic analyzing means configured to calculate, using a
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hydraulic analysis model including the water storage tank, a water leakage flow rate at each of the nodes in the water distribution network, a water flow rate from the distribution reservoir, and a flow rate from each of the nodes to the water storage tank coupled to this node;
index calculating means configured to calculate, using at least two of the water leakage flow rate, the water flow rate from the distribution reservoir, and the flow rate from each of the nodes to the water storage tank calculated by the hydraulic analyzing means, a leakage rate of water leakage occurring in the water distribution network and a satisfaction level of a water supply amount to the consumer with respect to supply pressure of water to the water distribution network; and
supply pressure determining means configured to determine supply pressure of water to the water distribution network, using the leakage rate and the satisfaction level calculated by the index calculating means,
(2) The water distribution management system according to (1), wherein
the water distribution network is divided into a plurality of areas, and intermittent water supply is executed for each of the areas,
the hydraulic analyzing means is configured to calculate a water leakage flow rate at each node, a water flow rate from the distribution reservoir, and a flow rate to the water
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storage tank for each of the areas, and
the index calculating means is configured to calculate a leakage rate and a satisfaction level of the entire plurality of areas with respect to supply pressure of water to each of the areas,
(3) The water distribution management system according to (1),
wherein
the water distribution network is divided into a plurality of
areas, and intermittent water supply is executed for each of
the areas,
the hydraulic analyzing means is configured to calculate a
water leakage flow rate at each node, a water flow rate from
the distribution reservoir, and a flow rate to the water
storage tank for each of the areas, and
the index calculating means is configured to calculate a
leakage rate and a satisfaction level of each of the areas
with respect to supply pressure of water to the area,
(4) A water distribution management system which performs
intermittent water supply from a distribution reservoir to a
consumer having a water storage tank coupled to each of the
nodes via a plurality of nodes in a water distribution
network, the water distribution management system including:
index calculating means configured to calculate a leakage rate
of water leakage occurring in the water distribution network
and a satisfaction level of a water supply amount to the
consumer with respect to supply pressure of water to the water
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distribution network, based on an actual measured value of supply pressure of water to the water distribution network, an actual measured value of a supply amount of water from the distribution reservoir to the water distribution network, and a total amount of actual measured values of water supply amounts from the respective nodes to the water storage tank; and
supply pressure determining means configured to determine supply pressure of water to the water distribution network, using the leakage rate and the satisfaction level calculated by the index calculating means,
(5) The water distribution management system according to (4),
wherein
the water distribution network is divided into a plurality of areas, and intermittent water supply is executed for each of the areas, and
the index calculating means is configured to calculate a leakage rate and a satisfaction level of the entire plurality of areas with respect to supply pressure of water to each of the areas, based on an actual measured value of supply pressure, an actual measured value of a supply amount, and a total amount of actual measured values of water supply amounts for each of the areas, and
(6) The water distribution management system according to (4),
wherein
the water distribution network is divided into a plurality of
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areas, and intermittent water supply is executed for each of the areas, and
the index calculating means is configured to calculate a leakage rate and a satisfaction level of each of the areas with respect to supply pressure of water to the area, based on an actual measured value of supply pressure, an actual measured value of a supply amount, and a total amount of actual measured values of water supply amounts for each of the areas.
[0008]
Moreover, in the present specification, "intermittent water supply" refers to a mode of water supply in which water is supplied to consumers only during a prescribed time slot (for example, from 6 AM to 9 AM and 5 PM to 8 PM in a day). A "supply amount" refers to an amount of water supplied from a distribution reservoir, and a "water supply amount" refers to an amount of water supplied from a node to a consumer. A "leakage rate" refers to a rate of a total water leakage amount to a supply amount when it is assumed that water leakage only occurs at each node, and a "satisfaction level" refers to a degree at which all consumers are satisfied with a water supply amount.
[0009]
The present invention can provide a water distribution management system capable of determining appropriate supply pressure based on a leakage rate and a satisfaction level even
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in a situation where a water storage tank is used in intermittent water supply.
BRIEF DESCRIPTION OF THE DRAWINGS [0010]
FIG. 1 is a schematic block diagram showing a configuration of a first embodiment of the present invention; FIG. 2 is a schematic view showing an example of a water distribution network to which a water distribution management system shown in FIG. 1 is applied;
FIGS. 3A and 3B are schematic views for explaining a water storage tank shown in FIG. 2, in which FIG. 3A shows an actual water supply model and FIG. 3B shows an integrated water supply model;
FIG. 4 is a schematic view showing an example of a demand pattern of water which is extracted by a consumer from a water storage tank;
FIG. 5 is a schematic flow chart showing a processing flow executed by the water distribution management system shown in FIG. 1;
FIGS. 6A to 60 are schematic views showing an example of a hydraulic analysis result by the processing flow shown in FIG. 5, in which FIG. 6A shows a flow rate from a certain node, FIG. 6B shows water pressure at the node, and FIG. 60 shows an example of a water level of a water storage tank coupled to the node;
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FIG. 7 is a schematic view which shows an index calculation
result by the processing flow shown in FIG. 5 and which
represents an example of a display screen provided by display
means;
FIG. 8 is a schematic view which shows results for each node
by the processing flow shown in FIG. 5 and which represents an
example of a display screen provided by display means;
FIG. 9 is a schematic block diagram showing a configuration of
a second embodiment of the present invention;
FIG. 10 is a schematic view showing an example of a water
distribution network to which a water distribution management
system shown in FIG. 9 is applied;
FIG. 11 is a schematic flow chart showing a processing flow
executed by the water distribution management system shown in
FIG. 9;
FIG. 12 is a schematic view which shows an index calculation
result of an entire area by the processing flow shown in FIG.
11 and which represents an example of a display screen;
FIG. 13 is a schematic view which shows an index calculation
result of a water distribution zone Zl by the processing flow
shown in FIG. 11 and which represents an example of a display
screen;
FIG. 14 is a schematic view which shows an index calculation
result of a water distribution zone Z2 by the processing flow
shown in FIG. 11 and which represents an example of a display
screen;
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FIG. 15 is a schematic view which shows an index calculation
result of a water distribution zone Z3 by the processing flow
shown in FIG. 11 and which represents an example of a display
screen;
FIG. 16 is a schematic block diagram showing a configuration
of a third embodiment of the present invention;
FIG. 17 is a schematic view showing examples of actual
measured values of supply pressure, a supply amount, and a
total water supply amount stored in a database shown in FIG.
16;
FIG. 18 is a schematic flow chart showing a processing flow
executed by the water distribution management system shown in
FIG. 16;
FIG. 19 is a schematic view which shows an example of an index
calculation result using the third embodiment and which
represents an example of a display screen;
FIG. 20 is a schematic view which shows another example of an
index calculation result using the third embodiment and which
represents an example of a display screen; and
FIG. 21 is a schematic view showing an example of a model used
in conventional hydraulic analysis.
DESCRIPTION OF THE PREFERRED EMBODIMENTS [0011]
Hereinafter, while first to third embodiments of the present invention will be described with reference to the drawings, it
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is to be understood that the present invention is not limited to the embodiments illustrated in the drawings. Moreover, in the present specification, a water column (m) is used as a unit of pressure including supply pressure. [0012]
First Embodiment
FIG. 1 is a schematic block diagram showing a configuration of a first embodiment of the present invention. A water distribution management system 1 is a system which performs intermittent water supply from a distribution reservoir to a consumer having a water storage tank coupled to each of the nodes via a plurality of nodes in a water distribution network and which is applied to, for example, a water distribution network such as that shown in FIG. 2. [0013]
In this case, for example, as shown in FIG. 2, a water distribution network 10 is constituted by a distribution reservoir Rl, a pressure reducing valve VI, a water distributing pipe 12, nodes Nl to N12 (hereinafter, the nodes Nl to N12 may also be referred to as a "node N"), and the like, and water of the distribution reservoir Rl is supplied via the pressure reducing valve VI, the water distributing pipe 12, and the node N to a plurality of consumers including residences and places of business by intermittent water supply. Each consumer has one of water storage tanks Tl to T12 (hereinafter, the water storage tanks Tl to T12 may also be
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referred to as a "water storage tank T") so that the consumer can always use water. Moreover, supply pressure of water supplied to the water distribution network 10 is adjusted by an opening of the pressure reducing valve VI. In addition, it is assumed that water leakage only occurs at each node N.
[0014]
Moreover, examples of reasons for performing intermittent water supply include a water supply utility not having a sufficient water supply amount to satisfy all consumers coupled to the water distribution network 10 due to a shortage at a water source or a shortage at a water treatment plant and being unable to perform continuous water supply.
[0015]
As shown in FIG. 1, the water distribution management system 1 is roughly constituted by input means 101, a database 201, hydraulic analyzing means 301, index calculating means 401, supply pressure determining means 501, and display means 601.
[0016]
The input means 101 inputs conditions such as supply pressure
(water pressure at a node N 102 directly under the pressure reducing valve VI) necessary for performing hydraulic analysis to be described later. As the input means 101, for example, a man-machine interface such as a keyboard or a mouse, or a network interface which retrieves data from an external network can be adopted.
[0017]
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The database 201 stores various types of information related to a model constituted by the water distribution network 10 shown in FIG. 2 (for example, information regarding a coupling path including the water distributing pipe 12 and the node N in the water distribution network 10 as shown in FIG. 2, elevations of each node N, water storage tank T, and demand node C, a demand pattern (a 24-hour time-series pattern of a total amount of water supplied to an individual consumer from the node C), a length and a resistance (roughness) of the water distributing pipe 12, and a formula used in pressure loss calculation (such as the Hazen-Williams formula)).
[0018]
The hydraulic analyzing means 301 uses a hydraulic analysis model including the water storage tank T to calculate a water leakage flow rate and pressure of each node N in the water distribution network 10, a water flow rate from the distribution reservoir Rl, and a flow rate from each node N to the water storage tank T coupled to this node N. Specifically, the hydraulic analyzing means 301 acquires the various types of information described above which are stored in the database 201 and executes a hydraulic analysis on the model. Moreover, a flow rate at each node N calculated by the hydraulic analyzing means corresponds to a water supply amount to the water storage tank T.
[0019]
A method of the hydraulic analysis described above is not
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particularly limited and, for example, a hydraulic analytical engine according to EPANET provided by the United States Environmental Protection Agency (refer to
https://www.epa.gov/water-research/epanet) can be used. In such hydraulic analysis, by providing a hydraulic analytical engine with the various types of information described above, water pressure at each node N and a water supply amount to the water storage tank T coupled to the node N with respect to supply pressure can be estimated. [0020]
In this case, a water supply amount from the node N to the water storage tank T can be calculated using an integrated water supply model which integrates a plurality of tanks. In other words, in reality, as shown in FIG. 3A, a plurality of individual consumers h exist with respect to a single node N, and a node N and an individual consumer h are coupled by an actual water supply pipe p (a water supply pipe coupled to the node N by the individual consumer h) via an actual tank t (a tank coupled to the node N by the individual consumer h) (an actual water supply model). However, the hydraulic analysis uses an integrated water supply model in which, virtually, as shown in FIG. 3B, a plurality of actual tanks t are integrated into a single integrated tank T (which corresponds to the water storage tank T shown in FIG. 2), a plurality of actual water supply pipes p are integrated into a single integrated water supply pipe P (which corresponds to the water supply
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pipe 13 shown in FIG. 2), and a plurality of individual consumers h are assumed to be a single consumer, in which case water is supplied to the consumer from a demand node C. Therefore, the water supply amount from the node N to the water storage tank T is determined depending on a diameter D of the integrated water supply pipe P, a sectional area S of the integrated tank T, and a demand pattern Q from the demand node C from which a consumer is supplied water.
[0021]
As the sectional area S of the integrated tank T, for example, an integrated value of an average sectional area SI of a plurality of actual tanks t (refer to tl to t6 in FIGS. 3A and 3B) coupled to the node N and the number n of a plurality of individual consumers h (refer to hi to h6 in FIGS. 3A and 3B) coupled to the node N may be used.
[0022]
The diameter D of the integrated water supply pipe P can be calculated using, for example, expression (1) below under the assumption that pressure loss by the water supply pipe p in the actual water supply model shown in FIG. 3A and pressure loss by the integrated water supply pipe P are equal. Diameter D of integrated water supply pipe P = diameter of water supply pipe p of actual water supply model x n0-38 ... (1) In expression (1), n denotes the number of individual consumers h coupled to the node N. An actual water supply model refers to an actual water supply system such as that
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shown in FIG. 3A.
[0023]
As the demand pattern Q from the demand node C described above, since a measured value of a 24-hour demand pattern is not available, for example, a demand pattern (refer to FIG. 4) in another water distribution network providing continuous water supply which is assumed to have a similar demand pattern
(for example, a water distribution network with a similar ratio of a residential area, a commercial area, and an industrial area) or a demand pattern calculated based on meter-reading data of an amount of water previously used by the individual consumer h may be used.
[0024]
The index calculating means 401 uses at least two of a water leakage flow rate, a flow rate from the distribution reservoir Rl, and a flow rate from each node N to the water storage tank T calculated by the hydraulic analyzing means 301 to calculate a leakage rate of water leakage occurring in the water distribution network 10 and a satisfaction level of a water supply amount to the consumer with respect to a supply pressure of water to the water distribution network 10.
[0025]
Specifically, based on a hydraulic analysis result obtained by the hydraulic analyzing means 301, the index calculating means 401 calculates a leakage rate and a satisfaction level with respect to supply pressure configured by the input means 101
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using, for example, expressions (2) and (3) below. Leakage rate (%) = total daily water leakage amount occurring in water distribution network 10/daily supply amount to water distribution network 10 x 100 ... (2)
Satisfaction level (%) = total daily water supply amount to all water storage tanks T in water distribution network 10/target water supply amount x 100 ... (3) [0026]
In expression (2) above, as the total water leakage amount, a sum of water leakage amounts at the nodes N which is obtained as a function of water pressure at the respective nodes N can be used and, as the supply amount, a sum of a sum of water supply amounts to the respective integrated tanks T and a sum of water leakage amounts can be used. [0027]
In expression (3) above, as the total water supply amount, a sum of the water supply amounts from the respective nodes N to the water storage tank T can be used and, as the target water supply amount, for example, a target value of a total daily water supply amount to all consumers by the water supply utility, an upper limit value of a total daily suppliable water amount to all consumers, or an average value of a daily water supply amount satisfying the individual consumer h x the number of individual consumers n can be used. Moreover, the target water supply amount is set to a value equal to or less than a maximum value of a suppliable water amount.
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[0028]
In addition, as the satisfaction level, besides the satisfaction level described above, for example, a proportion of consumers satisfied with the water supply amount (since measuring a water supply amount to the actual tank t coupled to each node N enables whether or not a consumer of the node N is satisfied with the water supply amount to be determined, a proportion of consumers satisfied with the water supply amount can be calculated) or a proportion of consumers satisfied with water pressure of the node N can be used.
[0029]
The supply pressure determining means 501 uses the leakage rate and the satisfaction level calculated by the index calculating means 401 to determine supply pressure of water to the water distribution network 10. A method used by the supply pressure determining means 501 to determine the supply pressure is not particularly limited and, for example, the supply pressure may be determined so that the leakage rate and/or the satisfaction level falls within a prescribed range
(determination criteria).
[0030]
The display means 601 displays the leakage rate and the satisfaction level with respect to the supply pressure obtained by the index calculating means 401. As the display means 601, for example, a display monitor can be adopted.
[0031]
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Moreover, as displayed on a display screen G2 shown in FIGS. 8A and 8B, the display means 601 may be configured to display minimum water pressure of each of the nodes Nl to N12 and a consumer satisfaction level (hereinafter, also referred to as an "individual satisfaction level") of each of the demand nodes CI to C12 obtained by hydraulic analysis. [0032]
The individual satisfaction level can be calculated using, for example, expression (4) below.
Individual satisfaction level = daily water supply amount to integrated tank Ti/target daily water supply amount to integrated tank Ti x 100 ... (4)
In expression (4), the target daily water supply amount to the integrated tank Ti can be calculated by, for example, multiplying a target daily water supply amount per each individual consumer coupled to the demand node Ci by the number of individual consumers n. Moreover, the target water supply amount can be determined as appropriate. In addition, the target daily water supply amount to the integrated tank Ti is equivalent to the target daily water supply amount to the demand node Ci. [0033]
In this manner, calculating the individual satisfaction level enables at which node a supply shortage has occurred to be discerned and a water supply amount from a specific node N can be improved by, for example, additionally installing a
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pressurizing pump at the node N.
[0034]
Next, a water distribution management method using the water distribution management system 1 will be described with reference to FIG. 5. In this case, the water distribution network 10 shown in FIG. 2 will be described as an example. In addition, water supply time points to the integrated tank T are assumed to be from 6 AM to 9 AM and from 5 PM to 8 PM in a day.
[0035]
When performing water distribution management, first, the input means 101 reads supply pressure which is input by a user and at which hydraulic analysis is to be performed (step S101) . Specifically, the input means 101 reads a range and a step size of supply pressure used for hydraulic calculations. Moreover, in this example, 15 m to 30 m is input as a range and 5 m is input as a step size of the supply pressure.
[0036]
Next, the hydraulic analyzing means 301 acquires various types of information of a hydraulic analysis model including a water storage tank T stored in the database 201 and, using the hydraulic analysis model, calculates water pressure of each node N and a flow rate (water supply amount) from each node N to the water storage tank T coupled to this node N with respect to the supply pressure (step S102).
[0037]
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Specifically, using a hydraulic analytical engine according to EPANET described earlier or the like, the hydraulic analyzing means 301 calculates a water leakage flow rate and water pressure of each node N, a water flow rate from the distribution reservoir Rl, and a water supply amount to each integrated tank T with respect to the supply pressure under conditions of the various types of information acquired from the database 201 and the supply pressure read by the input means 101. An example of a hydraulic analysis result is shown in FIGS. 6A to 6C. FIGS. 6A to 6C show a water supply amount from a certain node N, water pressure of the node N, and a water level of the integrated tank T coupled to the node N. Moreover, the water level of the integrated tank T can be calculated using, for example, the water supply amount and a demand pattern such as that shown in FIG. 4. [0038]
Next, the index calculating means 401 uses the water leakage flow rate, the water flow rate from the distribution reservoir Rl, and the flow rate from each of nodes N to the water storage tank T calculated by the hydraulic analyzing means 301 to calculate a leakage rate of water leakage occurring in the water distribution network 10 and a satisfaction level of a water supply amount to the consumers with respect to a supply pressure of water to the water distribution network 10 (step S103) . The index calculating means 401 calculates the leakage rate and the satisfaction level with respect to the supply
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pressure using, for example, expressions (2) and (3) described above. [0039]
Next, the display means 601 displays the leakage rate, the satisfaction level, and the like with respect to the supply pressure obtained by the index calculating means 401 (step S104) . An example of a calculation result of the respective indices (leakage rate and satisfaction level) displayed by the display means 601 is represented by a display screen Gl shown in FIG. 7. In this example, from an index characteristic graph, it is interpreted that supply pressure at which the satisfaction level reaches 100% is 23.8 m. [0040]
Next, the supply pressure determining means 501 uses the leakage rate and the satisfaction level calculated by the index calculating means 401 to determine supply pressure of water to the water distribution network 10 (step S105). Usually, since the lower the leakage rate, the better, and the higher the satisfaction level, the better, there is a trade¬off relationship between the leakage rate and the satisfaction level. Therefore, the supply pressure determining means 501 usually determines the supply pressure so that the satisfaction level is near 100%. In this example, the supply pressure 23.8 m is determined so that a 100% satisfaction level is attained. [0041]
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As shown, because the water distribution management system 1 is configured as described above, the water distribution management system 1 is capable of determining appropriate supply pressure based on a leakage rate and a satisfaction level even in a situation where a water storage tank T is used in intermittent water supply. [0042]
Second Embodiment
FIG. 9 is a schematic block diagram showing a configuration of a second embodiment of the present invention. A water distribution management system 2 is a system that is applied to, for example, a water distribution network which is divided into a plurality of areas Z and in which intermittent water supply is executed for each area Z as shown in FIG. 10. As shown in FIG. 9, the water distribution management system 2 is roughly constituted by the input means 101, a database 202, hydraulic analyzing means 302, index calculating means 402, supply pressure determining means 502, and the display means 601. The water distribution management system 2 differs from the first embodiment in that the water distribution management system 2 includes the database 202, the hydraulic analyzing means 302, the index calculating means 402, and the supply pressure determining means 502. Moreover, since the configurations of the input means 101 and the display means 601 are similar to those according to the first embodiment, same portions as the first embodiment will be denoted by same
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reference characters and a detailed description thereof will be omitted.
[0043]
In this example, the plurality of areas Z are the three water distribution zones Zl to Z3. Water stop valves V2 to V4 are respectively provided between the water distribution zones Zl to Z3 and the pressure reducing valve VI, and intermittent water supply to the water distribution zones Zl to Z3 is to be sequentially performed by opening and closing the water stop valves V2 to V4. Moreover, since such a water distribution method is capable of suppressing pressure loss in a water distribution network by performing the time division described above, water pressure at ends of the water distribution network can be secured with lower supply pressure and, consequently, a desired satisfaction level (100%) can be achieved. In addition, using lower supply pressure also has an effect of suppressing the leakage rate.
[0044]
The database 202 stores various types of information related
to a model constituted by a water distribution network 20
including the water distribution zones Zl to Z3 shown in FIG.
10.
[0045]
The hydraulic analyzing means 302 calculates, for each area Z, water pressure and a water leakage flow rate of each node N, a water flow rate from the distribution reservoir Rl, and a flow
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rate to the water storage tank T. Specifically, the hydraulic analyzing means 302 acquires the various types of information stored in the database 202 and executes a hydraulic analysis on the model described above using an EPANET hydraulic analytical engine. [0046]
The index calculating means 402 calculates a leakage rate and a satisfaction level of the entire plurality of areas Z (an entirety which compiles the water distribution zones Zl to Z3) with respect to supply pressure of water to each area Z. Specifically, using at least two of the water leakage amount of each node N, the water flow amount from the distribution reservoir Rl, and the water supply amount to each integrated tank T obtained by the hydraulic analyzing means 302, the index calculating means 402 calculates a water leakage amount at each node N and a supply amount from the distribution reservoir Rl based on the water pressure and the water supply amount and calculates a leakage rate and a satisfaction level of the entire water distribution zones Zl to Z3. [0047]
Next, a water distribution management method using the water distribution management system 2 will be described with reference to FIG. 11. In this case, the water distribution network 20 shown in FIG. 10 will be described as an example. In addition, water supply time points to the water distribution zone Zl are assumed to be from 3 AM to 6 AM and
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from 2 PM to 5 PM, water supply time points to the water distribution zone Z2 are assumed to be from 6 AM to 9 AM and from 5 PM to 8 PM, and water supply time points to the water distribution zone Z3 are assumed to be from 9 AM to 12 noon and from 8 PM to 11 PM. [0048]
When performing water distribution management, first, the input means 101 reads supply pressure which is input by a user and at which hydraulic analysis is to be performed (step S201) . Moreover, a range of the supply pressure in this example is 8 m to 25 m. [0049]
Next, the hydraulic analyzing means 302 acquires various types of information related to a model constituted by the water distribution zones Zl to Z3 stored in the database 202 and calculates, for each area Z, a water leakage amount and water pressure of each node N, a water flow amount from the distribution reservoir Rl, and a water supply amount to the water storage tank T (each integrated tank T) using a known hydraulic analytical engine such as the EPANET (step S202) . [0050]
Next, the index calculating means 402 calculates a leakage rate and a satisfaction level of the entire three water distribution zones Zl to Z3 with respect to the supply pressure (step S203). [0051]
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Next, the display means 601 displays the leakage rate, the satisfaction level, and the like with respect to the supply pressure obtained by the index calculating means 402 as represented by a display screen G3 shown in FIG. 12 (step S204) . In this example, it is interpreted that the supply pressure at which the satisfaction level reaches 100% is 14.2 m. Moreover, this value indicates that a mode in which water is intermittently supplied for each area as in the present embodiment enables supply pressure to be lowered in comparison to a mode in which water is intermittently supplied to a single area as in the first embodiment.
[0052]
Next, the supply pressure determining means 502 determines the supply pressure (step S205) . In this example, supply pressure of 14.2 m is determined so that a 100% satisfaction level is attained.
[0053]
Moreover, in the water distribution management system 2, it is also preferable that the index calculating means 402 calculates a leakage rate and a satisfaction level for each area Z (the water distribution zones Zl to Z3) with respect to supply pressure of water to each area Z (the water distribution zones Zl to Z3). Specifically, using the water pressure of each node N and the water supply amount to each integrated tank T obtained by the hydraulic analyzing means 302, the index calculating means 402 calculates a water
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leakage amount at each node N and a supply amount from the distribution reservoir Rl based on the water pressure and the water supply amount and calculates a leakage rate and a satisfaction level of each of the water distribution zones Zl to Z3.
[0054]
In this example, as displayed on display screens G4 to G6 shown in FIGS. 13 to 15, it is interpreted that the supply pressure at which the satisfaction level reaches 100% is respectively 14.0 m, 22.2 m, and 10.8 m in the water distribution zones Zl to Z3. Therefore, by calculating a leakage rate and a satisfaction level for each area Z, more appropriate supply pressure can be determined for each area Z.
[0055]
As shown, because the water distribution management system 2 is configured as described above, the water distribution management system 2 is capable of determining appropriate supply pressure even in a situation where, for example, intermittent water supply is sequentially performed to different areas Z.
[0056]
Third Embodiment
FIG. 16 is a schematic block diagram showing a configuration of a third embodiment of the present invention. A water distribution management system 3 is applied to, for example, the water distribution network 10 as shown in FIG. 2. As shown
28

m FIG. 16, the water distribution management system 3 is roughly constituted by the input means 101, a database 203, index calculating means 403, the supply pressure determining means 501, and the display means 601. The water distribution management system 3 differs from the first embodiment in that the water distribution management system 3 does not include hydraulic analyzing means but includes the database 203 and the index calculating means 403. Moreover, since the configurations of the input means 101, the supply pressure determining means 501, and the display means 601 are similar to those according to the first embodiment, same portions as the first embodiment will be denoted by same reference characters and a detailed description thereof will be omitted.
[0057]
The database 203 stores various types of information for calculations to be performed by the index calculating means 403. Specifically, the database 203 stores, for example, a plurality of data sets of a supply amount and a water supply amount actually measured while applying mutually different supply pressure as shown in FIG. 17. Moreover, the supply pressure is pressure at a node N 102 while water is being supplied to the water storage tank T and the supply pressure can be varied as appropriate.
[0058]
Based on an actual measured value of supply pressure of water to the water distribution network 10, an actual measured value
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of a supply amount of water from the distribution reservoir Rl to the water distribution network 10, and a total amount of actual measured values of water supply amounts from the respective nodes N to the water storage tank T, the index calculating means 403 calculates a leakage rate of water leakage occurring in the water distribution network 10 and a satisfaction level of a water supply amount to the consumers with respect to a supply pressure of water to the water distribution network 10. [0059]
In this case, the leakage rate and the satisfaction level can be calculated using, for example, expressions (5) and (6) below.
Leakage rate (%) = water leakage amount/supply amount x 100 ... (5)
Satisfaction level (%) = water supply amount/target water supply amount x 100 ... (6) [0060]
In expression (5) above, as the water leakage amount, a difference between a supply amount and a water supply amount can be used. In expression (6) above, as the target water supply amount, for example, a target value of a total water supply amount to all consumers by the water supply utility during a period, an upper limit value of a total suppliable water amount to all consumers during the period, or an average value of a water supply amount satisfying the individual
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consumer h during the period x the number of individual consumers n can be used.
[0061]
Next, a water distribution management method using the water distribution management system 3 will be described with reference to FIG. 18. When performing water distribution management, first, the input means 101 reads supply pressure which is input by a user and for which indices (leakage rate and satisfaction level) are to be calculated (step S301). Moreover, a range of the supply pressure in this example is 15 m to 30 m.
[0062]
Next, the index calculating means 403 acquires actual measured values of a supply amount and a water supply amount with respect to the supply pressure stored in the database 203. Next, based on the actual measured values of the supply pressure, the supply amount and the water supply amount acquired from database 203, the index calculating means 403 calculates the leakage rate and the satisfaction level with respect to the supply pressure using expressions (5) and (6) described above (step S302).
[0063]
Next, the display means 601 displays the leakage rate, the satisfaction level, and the like with respect to the supply pressure obtained by the index calculating means 403 (step S303) . In this example, the target water supply amount is set
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to 100,000 m3 and supply pressure is changed every other month as displayed on a display screen G7 shown in FIG. 19. From the diagram, it is interpreted that the supply pressure at which the satisfaction level reaches 100% is 23.8 m.
[0064]
Next, the supply pressure determining means 501 determines the supply pressure (step S304) . In this example, the supply pressure 23.8 m is determined so that a 100% satisfaction level is attained.
[0065]
Moreover, FIG. 20 shows a display screen G8 representing a result when the supply amount reaches a suppliable upper limit value. In this example, the supply amount has reached an upper limit of 141,500 m3 at supply pressure of 30 m, indicating that applying excessive supply pressure of 30 m causes the leakage rate to increase and the satisfaction level to decline.
[0066]
As shown, because the water distribution management system 3 is configured as described above, the water distribution management system 3 is capable of determining appropriate supply pressure based on a leakage rate and a satisfaction level even in a situation where a water storage tank T is used in intermittent water supply.
[0067]
It is to be understood that the present invention is not limited to the configurations of the embodiments described
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above and that the invention is defined by the claims and intended to cover all equivalences of the claims as well as all changes that fall within the claims. [0068]
For example, while the water distribution management system 3 applied to the water distribution network 10 shown in FIG. 2 has been described in the third embodiment, a water distribution management system according to the present invention may divide a water distribution network into a plurality of areas and execute intermittent water supply for each area as shown in the second embodiment and the index calculating means may calculate a leakage rate and a satisfaction level of the entire plurality of areas with respect to supply pressure of water to each area, based on an actual measured value of supply pressure, an actual measured value of a supply amount, and a total amount of actual measured values of water supply amounts for each area, or may divide a water distribution network into a plurality of areas and execute intermittent water supply for each area and the index calculating means may calculate a leakage rate and a satisfaction level of each area with respect to supply pressure of water to the area, based on an actual measured value of supply pressure, an actual measured value of a supply amount, and a total amount of actual measured values of water supply amounts for each area. Accordingly, appropriate supply pressure can be determined based on a leakage rate and a
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satisfaction level even in a case where, for example, intermittent water supply is sequentially performed to different areas. [0069]
In addition, while the water distribution management systems 1 to 3 in which the supply pressure determining means 501 and 502 determine supply pressure using both a leakage rate and a satisfaction level have been described in the embodiments above, a water distribution management system may be configured such that the supply pressure determining means determines the supply pressure using any of a satisfaction level and a leakage rate.
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