EP4698876A1

EP4698876A1 - Method for locating water leaks in a water supply network and computer program based on said method

Info

Publication number: EP4698876A1
Application number: EP24734957.4A
Authority: EP
Inventors: Mario PUTTI; Antonia LARESE DE TETTO; Nicola SEGALA; Francesco Marchetti; Cristina SCARPEL; Massimo RAMAZZOTTO
Original assignee: Almaviva Bluebit SpA Benefit Soc
Current assignee: Almaviva Bluebit SpA Benefit Soc
Priority date: 2023-04-26
Filing date: 2024-04-24
Publication date: 2026-02-25
Also published as: IT202300008196A1; WO2024224320A1

Abstract

A method for locating water leaks in a water supply network comprising the steps: a) arrangement of the layout of the water supply network; b) definition of the initial node (0) and of the final node (8) of said layout; c) determination of the flow rate (q_IN; q_OUT) associated with the initial node and final node in the absence of water leaks; d) definition of the distribution of a reference water demand associated with the layout in the absence of water leaks; e) measurement of one or more physical quantities (h_{2_MIS}; h_{5_MIS}) associated with the water in a subset of nodes of the layout; f) definition of one or more parameters (p, w) variable as a function of the geometric characteristics and surface properties associated with the piping and connections of the layout; g) determination of a distribution of the parameters (p, w); h) determination of a distribution of operative water demand associated with the nodes; i) comparison between said distribution of operative water demand and the distribution of a reference water demand to determine the differential; a possible step j) of assignment of a new distribution of said one or more parameters (p', w'); k) repetition of step h) and step i) by using the new distribution of the parameters (p', w'); I) identification of one or more water leaks associated with the layout as a function of the trend of the parameters distribution (p', w') used during the last execution of said step h).

Description

METHOD FOR LOCATING WATER LEAKS IN A WATER SUPPLY NETWORK AND COMPUTER PROGRAM BASED ON SAID METHOD

DESCRIPTION

[001] The present invention relates the technical field relating to the water supply maintenance and, in particular, relates to a method for locating water leaks in a water supply network.

[002] A further object of the present invention is a computer program intended to implement the method for locating water leaks in a water supply network.

State of the art

[003] As is well known, the technical field of water supply (both drinkable and nondrinkable) is characterized by a high level of maintenance activity, particularly aimed at detecting any water leaks that may afflict piping, connections, pumps, etc.

[004] Over the years, many methods intended to locate water leaks along the piping have been developed.

[005] For example, one technology, now well established in the field, makes it possible to determine possible water leaks on a network through the use of detection device of the electro-acoustic type.

[006] These devices are designed to detect and amplify a plurality of waves of a mechanical nature (generally vibration waves) generated by the leakage of pressurized water from water pipes; these vibrations propagate along the piping from the point where the leak occurred.

[007] In particular, three detection techniques using as many electro-acoustic tools are commonly used. Firstly, a technique based on a pre-listening rod (rod in contact with the pipe so as to detect the vibration and an electronic control unit capable of amplifying this noise so as to make it audible to an operator) is known.

[008] Secondly, a method based on the geophone is known (noise is detected directly from the ground by placing a piezoelectric sensor directly in contact with the ground at the piping). Thirdly, a correlator-based method is also in use (it is provided for a pair of sensors suited to translate the sound into an electrical signal, a processing unit is configured to process such signal according to the diameter, length, material of construction of the pipe in order to locate the noise generation point).

[009] The main limitation of this technology lies in the difficulty of using it, since the measurement context is increasingly affected by acoustic/environmental noise of a different nature.

[0010] This condition is well known especially in urban and/or industrial contexts where the presence of mechanical wave sources is particularly widespread.

[0011] For example, motor vehicles (cars, heavy vehicles, etc.) travelling on roads obtained in surface, can generate vibrations and/or noise in the ground at very wide frequencies that propagate in depth until they interfere with the waves generated by the leak itself.

[0012] Consequently, measurements made with these techniques are often inaccurate and their validity must be confirmed from time to time through an on-site exploration by specialised technicians.

[0013] A further drawback associated with water leaks detection systems by means of electro-acoustic sensors stems from the fact that the vibrations associated with a leak are only detectable if the water pressure does not fall below 3 bar. For lower pressure values, in fact, the tools fail to detect vibrations generated by a water leak, especially when the piping are made of polymeric material (a material that limits the propagation of mechanical waves), or in the event that the piping has an insufficient number of listening points.

[0014] Another drawback associated with this technology lies in the fact that it is possible to detect the presence of leaks only when they occur but does not allow predicting future criticality on the water supply network itself.

[0015] To overcome such drawbacks, alternative analysis technologies have been developed whose operation is based on radar investigation techniques based on signals of electromagnetic type.

[0016] In particular, these technologies use satellites and aircraft on which is installed a radar device capable of operating with electromagnetic radiation having a frequency in the microwave spectrum (L-band).

[0017] In use, these radar supports fly over areas of territory in which a water supply network is underground; such network is hit by the electromagnetic waves generated by the radar, which penetrate into the ground (within the first few metres) and are then reflected by the piping and detected by the radar itself.

[0018] These radars are capable of detecting alterations in the reflectance of electromagnetic radiation associated with the medium under investigation (soil, subsoil and piping) and the processing of this electromagnetic signal makes it possible to identify the presence of drinkable water in the ground on the basis of the estimates of the dielectric constant and the electrical conductivity associated with the objects hit by the electromagnetic radiation.

[0019] From the analysis of the electromagnetic signal received by the radar and processed by the CPU, it is possible to estimate one or more points in the water supply network where there is a leak or a water spill.

[0020] However, the solution described above has some drawbacks that limits its application.

[0021] Firstly, the electromagnetic radiation emitted by the radar system could undergo alterations or be blocked by the presence of other electromagnetic fields in the environment or by shadow cones.

[0022] In addition, the radar systems in use nowadays do not allow the presence of drinkable water leaks (caused by a leak) to be discriminated from accumulations or spills of water formed by natural causes.

[0023] Finally, the use of radar detection systems does not make it possible to obtain a real-time mapping of the water supply network, since this technique can determine the network state only at the instant of scanning.

[0024] In fact, this technique does not make it possible to predict the state of the water supply network (and the occurrence of any leaks) at times subsequent to the one in which the measurement was carried out.

Presentation of the invention

[0025] The present invention intends to overcome the above-mentioned drawbacks by providing a method for locating water leaks in a water supply network which is particularly efficient and high-performing.

[0026] In particular, the main purpose of the present invention is to provide a method for locating water leaks in a water supply network with high accuracy and reliability, without the use of radar or sonic systems.

[0027] Another purpose of the present invention is to provide a method for locating water leaks in a water supply network that can be carried out without the use of specialized personnel in the control of acquisition equipment (e.g. satellites or similar).

[0028] A further purpose of the present invention is to provide a method for locating water leaks in a water supply network that can be implemented without requiring complex measurements on the network of the type that can only be carried out by specialized personnel.

[0029] A further purpose of the present invention is to provide a method for locating water leaks in a water supply network that is capable of discriminating with high accuracy water leaks associated with the network from other type of water accumulations in the soil.

[0030] Not the least purpose of the present invention is to provide a method for locating water leaks in a water supply network is capable of providing long-term predictions on the state of the network without requiring continuous execution of measurements or frequent inspections.

[0031] These purposes are achieved by a method for locating water leaks in a water supply network according to claim 1.

[0032] Other purposes that will be better described below are achieved by a method for estimating water leaks in a water supply network in accordance with the dependent claims.

[0033] The same purposes are also achieved by a computer program implementing the method for locating water leaks in a water supply network, this computer program is in accordance with claim 15.

Brief description of the drawings

[0034] The advantages and features of the present invention will emerge clearly from the following detailed description of some preferred, but not limiting, configurations of a method for locating water leaks in a water supply network with particular reference to the following drawings:

- Figure 1 is a schematic view of the layout of a water supply network;

- Figure 2 comprise diagrams associated with a distribution of a particular parameter used in the method according to the invention.

Detailed description of the invention

[0035] As will be better clarify below, the present invention relates to a method for locating water leaks in a water supply network, in general intended to serve domestic and/or industrial users.

[0036] The water supply network generally consists of a set of elements necessary to promote the circulation of water along a predetermined path.

[0037] In general, the water supply network is at least partially underground and consists of elements known in themselves and not further described in the present description, e.g. piping, connections, valves, pumping systems, etc.

[0038] The invention that is object of the present invention provides the making of a method that can be applied to any type of water supply network, regardless of its length, complexity, flow rate and configuration. The only essential condition for the application of the method described here is the fact that the circulation of water within the elements of the water supply network always takes place under pressure and never free-flowing.

[0039] Some definitions associated with a water supply network are reported below, which will be taken up later when describing the steps of the method object of the present invention.

[0040] Firstly, a water supply network comprises a plurality of piping and a plurality of connections.

[0041] The term “connection”, used in this context, refers to a point of the water supply network at which two or more piping are connected to each other.

[0042] For this reason, even the junction of only two pipes defines a connection point, since the ends of the pipes themselves must couple in ensure water tightness.

[0043] A fortiori, the connection of three or more piping also defines a connection point. [0044] In the case of malfunctioning or water supply network breakage, it is experimentally proven that water leak occurs more frequently at a connection point.

[0045] However, piping is also subject to wear and/or breakage, and, for this reason, it is possible for a crack or hole to arise in the tubular body in areas away from the connection points.

[0046] The present method can be used to estimate the presence of a leak in a water supply network either at a connection point or along a piping.

[0047] The fluid-dynamic theory allows the behaviour of a water flow within a circuit delimited by piping to be described.

[0048] It is, therefore, possible to apply this fluid-dynamic theory also to the water supply networks to which the method here described refers. In particular, by applying the teachings of the fluid-dynamics theory to water supply networks, the behaviour of the water flow circulating within the piping and connection points satisfies two particular conditions.

[0049] Firstly, a water mass balance relation can be applied at all points in the water network. [0050] The mass balance condition states how, at any section of the water supply network, the sum of the incoming flows is equal to the sum of the outgoing flows.

[0051] Consequently, in a section placed at a connection between two or more piping, the water flow entering the connection is equal to the water flow outgoing such connection.

[0052] In addition, the fluid circulating within a water supply network also satisfies a second condition relating to the momentum balance.

[0053] This condition establishes the constitutive law that relates the pressure difference between the nodes at the ends of each piping and the flow rate of the fluid passing through such piping.

[0054] From this relation, it is, therefore, possible to define the momentum balance in terms of energy constancy, i.e. the sum of the kinetic energy, associated with the water flow passing within a piping, and the potential energy of the water flow at the ends of the piping result to be constant.

[0055] This energy is distributed between a kinetic component and a potential component, the sum of which, however, can never exceed the initial value.

[0056] In view of the above, the behaviour of the fluid circulating within a water supply network have to simultaneously fulfil the conditions of mass balance and momentum balance.

[0057] By applying the law of mass balance and conservation of the momentum to the water flow, each network or aqueduct can be described by two fundamental quantities.

[0058] The first quantity is the piezometric height, defined at each point in the water supply network as the sum between the water pressure and elevation with respect to a height of global reference.

[0059] The piezometric height expresses a link with the punctual potential energy for mass unit at each point of the water supply network.

[0060] The second quantity is the water flow rate, defined as the volume of water per unit of time passing through a pipe of the network.

[0061] An external parameter that influences the dynamics of a flow of water circulating in a water supply network is the force (or hydraulic demand), which can be defined as the value of the water flow outgoing the water supply network itself.

[0062] More specifically, the force can be intended as the amount of water required by a water utility connected to the water supply network. [0063] In the present context, the expression "leakage of water flow from the water supply network" describes a condition of withdrawal of water from the same network by a water utility.

[0064] In other words, the water demand (or force) indicates the amount of water that users external to the network require by means of a withdrawal.

[0065] It is, however, important to point out that the distribution of the water demand associated with the users is not affected by any water leaks affecting the network itself. [0066] However, water flow leaking out of the network due to the presence of breaking in pipes, connections, valves or other components of the network can be equated with new points of water demand since, although they are not associated with a real water utility, they can be considered as actual points of withdrawal.

[0067] A way to distinguish a force associated with a withdrawal of a water utility from a force associated with one or more leaks is to assess the time aspect, i.e. the duration of a force.

[0068] It is possible to associate a force with a water utility when the duration of that force is time-limited (or otherwise finite).

[0069] This criterion is based on the fact that water utilities connected to a water supply network require the withdrawal of water only for limited and finite times, suffice it to know that the withdrawal of water for food, sanitary, hygienic purposes, etc.

[0070] Conversely, it is possible to identify a leak by means of a force of unlimited duration, i.e. such that it arises from a certain moment onwards without an interruption being expected.

[0071] When the force is associated with a leaks, the behaviour of such force can be described by means of two specific parameters.

[0072] In particular, it is possible to define a first parameter, indicated in the present description with the letter C, associated with the size of the breach at a node in the network. The first parameter C, therefore, basically represents the diameter of the hole associated with the leak.

[0073] It is also provided a second parameter, indicated in the present description by the letter y, related to the geometric shape of the breach.

[0074] For example, the parameter y varies depending on whether the breach or breaking is in the form of a circular hole or an extended crack.

[0075] The method, which is the object of the present invention comprises a first step a) of arrangement of the layout of the water supply network.

[0076] The layout of the water supply network can be considered as a graph formed by nodes and sides.

[0077] In particular, the set of piping that make up the water supply network define the arcs (or sides) of the underlying graph of the water supply network.

[0078] On the other hand, the connection points in the water supply network constitute the nodes in the layout.

[0079] Conveniently, the graph constituting the layout can be closed (i.e. define a closed circuit water supply network), or open (i.e. define an open circuit water supply network). [0080] In a particular configuration of the method, the step a) can be executed by the water supply network authority, who is able to arrange an accurate and complete layout of the network.

[0081] In the implementation of the method object of the invention, it is essential to have a layout of the water supply network that is complete, accurate and consistent with the actual configuration thereof, so as to ensure the success of the subsequent steps of the method itself.

[0082] When the execution of step a) is based on accurate, complete and consistent information provided by the network authority or other parties, such information allows a final layout of the water supply network to be arranged without requiring the execution of further sub-steps.

[0083] However, when the information associated with the layout of the water supply network is partial, incomplete or inconsistent, during the execution of step a) further substeps suited to allow for the arrangement of a definitive layout of the water supply network are provided.

[0084] In particular, it is possible to provide the step a¹) suited to identify, on the basis of starting information provided by the water network’s authority or other parties, the presence of any erroneously double or overlapping piping and to remove excess pipes. [0085] With the expression “duplicate piping” it is intended the duplication of a same piping or a section of the water supply network; this condition, of course, does not correspond to the actual state of the network, but is an error in the arrangement of the layout that is very often encountered in real-life situations.

[0086] In general, the network authority can provide some specific information about the water supply network, which most often allows to know the diameter of the piping, their length, position and direction of laying, and the date of installation (i.e. the dating of those Piping).

[0087] During the execution of step a¹), a comparison of the information provided by the water network authority is carried out in order to detect the eventual presence of duplications between some of them.

[0088] The duplication of information identifies a theoretical error (not present in practice) due to the fact that the layout, as determined by the information provided by the network authority, has several piping (duplicated) at the same point of the layout.

[0089] The step a¹), also allows to remove all erroneously duplicated piping from the layout by executing a further comparison of all similar piping, i.e. piping that are a copy of each other.

[0090] In other words, the comparison performed during the step a¹), only examines piping that represent the duplication of the same section of pipe, connection or other element of the water supply network.

[0091] Following this comparison, it will be possible to remove all incorrect piping from the layout, i.e. those piping that, although ideally present in the information provided by the authority, may not have been installed in practice as long as they are incongruent with the characteristics of the layout itself.

[0092] For example, piping with geometric dimensions (diameter and length) in contrast with the elements present upstream and/or downstream in the layout constitute obvious inconsistencies and can therefore be removed from the layout.

[0093] Another discriminating factor may be the laying date of the piping; in this case, the piping actually present in the water supply network is the most recent one, while the older one is to be considered removed and replaced by the most recent piping.

[0094] The step a) also comprises a sub-step a") suited verify the possible presence of piping ends that are not connected to other elements of the water supply network.

[0095] In other words, during the execution of the sub-step a") it is possible to detect all piping associated with the layout provided by the network authority that are not fluidically connected to the upstream or downstream piping.

[0096] When this situation occurs, the sub-step a") promotes the forced connection of two ends of the piping arranged in a side-by-side position, effectively changing their length so as to define a continuous circuit for water.

[0097] Step a) may also provide the execution of the sub-step a'") suited to insert in the layout any new piping/connections do not present according to the information provided by the network authority.

[0098] The lack of piping or other elements of the water supply network is a condition that occurs when the information held by the network authority does not take into account any upgrades/maintenance/changes made to the water supply network over the time.

[0099] Basically, the step a¹") allows the detection of all parts of the layout that, according to the data provided by the network authority, are ideally disconnected, i.e. define interruptions along the path defined by the layout.

[00100] This condition is impossible in practice (when the water supply network is fully functioning) and the purpose of the step a'") is to correct these inconsistencies by inserting new piping into the layout suited to define a continuous (and consistent) path for the water flow.

[00101] In particular, during the execution of the step a'"), two types of piping can be added to the layout: i) the main piping and ii) the connections.

[00102] In general, the main piping represents the fluidic backbones of the water supply network, i.e. those piping intended to allow the circulation of water with a relatively high flow rate so as to serve a large number of water utilities.

[00103] By convention, the main piping are placed in areas easily accessible so that to make it possible an easy intervention of one or more operators in case of emergency or maintenance.

[00104] For example, if the layout is associated with a water supply network connected to the aqueduct, the main piping are often buried under roads or undeveloped areas so as to prevent a section thereof from developing below foundations or jetties of concrete that prevent their access.

[00105] The connections, on the other hand, represent sections of the layout having reduced flow and extension as they are suited to connect a water utility (e.g. a residential building) with a respective main piping.

[00106] At the end of the step a"'), the layout of the water supply network obtained is substantially consistent with the real one in that there are no inconsistencies or gaps in the piping connection.

[00107] However, the layout obtained following the execution of the steps a¹)- a¹") can be further modified in order to optimise it with respect to a model of aqueduct network that take into account the conditions associated with both the mass and momentum balance of the water flowing through it.

[00108] In particular, the value of the momentum is always locally constant, i.e. , for each side of the layout, this value does not change along the development (or length) of the side itself.

[00109] To this end, a further step a^lv) may be provided in which the layout obtained at the end of the execution of the step a'") is further modified by entering the position of the valves and pumps forming part of the water supply network. The information associated with the valves and pumps may be provided directly by the network authority (and included in the starting information already used during the execution of the step a¹)), or they may be entered ex novo even if the starting information does not include references to these components.

[00110] Still during the execution of the step a^lv) of optimization of the layout arrangement, the layout conformation is modified in order to insert fictitious nodes (or connections) so as to establish a maximum length of each single piping that is shorter than an arbitrary and predetermined reference value.

[00111] In general, the reference value of the maximum piping length may be chosen on the basis of the geometric conformation of the network, so as to achieve a degree of accuracy that allows for an accurate and consistent representation of the water supply network.

[00112] By doing so, all sides of the layout are forced to have a maximum length not exceeding this value.

[00113] Downstream of the sub-step a^lv) it is provided a sub-step a^v) suited to establish, for each node of the layout (whether real or fictitious), the value of the piezometric height, by solving a fluidynamic model based on the combination of the principles of conservation of momentum and conservation of mass.

[00114] From the information provided by the network authority (used during the execution of the sub-step a¹) - a^v)) it is possible to estimate the value of the piezometric height at the layout nodes. In addition, it is also possible to estimate the value of the piezometric height in the case of fictitious nodes added to the layout during the execution of the step a^lv.

[00115] The elevation value of each node, on the other hand, can easily be found from the soil/building conformation in which the water supply network is installed. For example, the elevation of a site can be found from cartography (geographical coordinates) or specialised databases.

[00116] In view of the above, step a) comprises the sub-steps a')-a^v), the execution of which makes it possible, starting from information associated with the water supply network and provided by the network authority or alternative parties, to obtain an accurate and consistent layout of the actual water supply network on which the presence of leaks is to be estimated.

[00117] The method also provides for a step b) of definition of an initial node and a final node of the layout arranged during step a). Step b) is commonly referred to in technical jargon as the districting step.

[00118] The expression “initial” and “final” associated with these two nodes follows the direction of the flow circulating within the layout.

[00119] The water flow, in fact, circulates in the layout with a circulation direction from the initial node to the final node, progressively passing through all the intermediate nodes that constitute the layout.

[00120] The flow (or fractions of the flow) passes through all reachable nodes between the initial node and the final node in a progressive manner, i.e. according to the pressure distribution within the layout.

[00121] Conveniently, the method comprises a step c) of determination of the flow rate q_in, measured at the initial node of the layout, and the flow rate q_out, measured at the final node of the layout.

[00122] The flow rates q_in and q_out, associated with the initial and final nodes of the layout, may be obtained through measurements or, alternatively, may be provided by the network authority if they are project data of the network itself.

[00123] Following step c), there is a step d) of definition of the distribution of water demand at the nodes and/or sides of the layout.

[00124] This distribution is called the “reference water demand distribution”, as it is determined in the absence of water leaks, i.e. assuming that the network has no unwanted water leaks.

[00125] In general, the reference water demand defined in step d) is also a data in the availability of the network authority as it often represents a project data of all aqueduct networks.

[00126] It is also provided a step e) of measurement one or more physical quantities associated with the water flow circulating within a subset of nodes and/or sides of the layout. These measurements take into account any leaks present in the layout.

[00127] When executing step e) some nodes and/or sides of the layout are extracted representing a subset of the entire number of these elements.

[00128] The purpose of step e) is to detect, at this subset of nodes, the local behaviour of water flow by measuring one or more physical quantities.

[00129] Conveniently, during the execution of this step, the pressure associated with the water flow at the nodes and/or sides belonging to the subset is measured.

[00130] From the measurement of the water pressure at the nodes and/or sides of the subset, it is possible to calculate the instantaneous piezometric height associated with such nodes.

[00131] It is also provided a step f) of definition of one or more parameters p, w whose value is variable depending on the geometric characteristics and/or surface characteristics associated with the elements composing the water supply network: piping, valves, connections, etc.

[00132] The parameters p, w defined in step f) can be variable depending only on the geometric characteristics of the network or only on the surface characteristics of the elements forming the network itself (e.g. the roughness of the pipe).

[00133] More generally, these parameters p, w can be variable as a function of both these characteristics (geometric and surface characteristics of the elements that make up the water network).

[00134] For example, the parameters p, w may vary depending on the following characteristics associated with the elements defining the layout:

- the diameter of the piping I connections I valves I etc. defining the layout;

- the length of piping I connections I valves I etc. defining the layout;

- the roughness coefficient associated with the internal surfaces of the piping I connections I valves I etc. that define the layout;

- the material used for the piping I connections I valves I etc. that define the layout;

- the age (i.e. time elapsed since installation) of the piping /connections/ valves I etc. defining the layout.

[00135] The method also provides a step g) of determination of a distribution of the parameters p, w defined in the previous step f).

[00136] In step g), therefore, it will be possible to associate a value (or range of values) of the parameters p, w for each node and/or side of the layout. [00137] In particular, starting from the layout [determined in step a)] and the distribution of a reference water demand without leaks [determined in step d)], it is possible to determine (or calculate), while executing a step g), a distribution of the parameters p, w also of reference, i.e. the determination of these parameters p, w for each node and/or side of the layout in the absence of water leaks coming out from the layout.

[00138] As will be better explained hereafter, this calculation can be performed by an iterative process of successive approximations.

[00139] Following the execution of step g), step h) is provided to calculate a new distribution of water demand, better defined hereafter as operative demand.

[00140] To calculate the operative water demand, it is necessary to know the value of the following factors:

- the flow rate q_in of the water flow defined at the initial node of the layout;

- the flow rate q_out of the water flow defined at the final node of the layout;

- the distribution of the parameters p, w determined in step g);

- the physical quantities measured in the subset of nodes and/or sides e).

[00141] During the execution of step h), the distribution of the hypothetical, and therefore not real, water demand (associated with the water utility connected to the layout) is, therefore, calculated. The value of this distribution is calculated starting from the above factors (flow rate of the water flow in the initial/final node of the layout, distribution of parameters p, w and measured physical quantities) obtained in the previous steps of the method.

[00142] The water demand distribution calculated in step h) does not refer to the leak- free layout, which, as it is known, has a water distribution equal to the reference one. However, when one or more leaks are present in the layout at the nodes and/or sides, it is possible to hypothesise a "transformation" of the present layout in such a way as to change its initial water demand (corresponding to the reference water demand - in the absence of leaks) to an operative water demand that takes leaks into account, but which does not exist in reality. This operative water demand can therefore be associated with a "new" layout having the same shape characteristics, but different parameters associated with geometrical characteristics and/or surface properties of the piping and connections that form the nodes of this "new" layout.

[00143] In other words, the water demand distribution calculated in step h) and in the subsequent steps of the method described below refers to a hypothetical layout having characteristics such that it has one or more water leaks compared to the reference layout.

[00144] As will be better clarified later in this description, the parameters p and w, associated with this hypothetical layout, may be updated iteratively, so as to define at the end of this iteration a final layout (again hypothetical) which, however, well approximates the reference water demand (which, in practice, remains substantially constant even in the event of leaks). A hypothetical layout of this type therefore presents a water demand that is consistent with the one actually present in reality (since the reference water demand identifies a condition that is preserved over time), but at the same time this layout is associated with certain parameters p and w (the distribution of which is updated during the iterative steps of the method and contains information relating to the nodes/sides of the layout defined in step a) in which there is one or more water leaks.

[00145] The method then provides the execution of a step i) of comparison of the operative water demand distribution, calculated in step h), with the reference water demand, defined in step d).

[00146] The outcome of this comparison makes it possible to define a distribution differential of water demand presents between the distribution calculated during the execution of the step h) and the distribution defined in step d).

[00147] It is possible to define a predetermined threshold for this differential, i.e. establish a value (for each point or side of the layout) above which the difference between the two water distributions is too high and, for that reason, cannot be acceptable.

[00148] In other words, the threshold value defines the maximum permissible error between the two water demand distributions (the calculated one and the ideal starting one).

[00149] The following procedure generically describes a way used by the present method to minimise the amplitude of this error bringing it to a value lower than the preset threshold value.

[00150] The originality of the present method lies in the fact that it performs such minimisation by varying only the parameters p, w, i.e. by defining (by means of one or more steps) a final distribution of such parameters with which it is possible to calculate a new operative water demand distribution that differs from the reference distribution by a value lower than the pre-set threshold.

[00151] In particular, when the differential determined in step i) exceeds the threshold value, the present method may provide for the execution of two specific steps described below.

[00152] First, it is provided a step j) of assigning a new distribution of parameters p, w associated with the nodes and/or sides of the layout.

[00153] The values of these parameters p, w, assigned in step j) (hereinafter referred to as p', w') are different from the values of the distribution assigned to the same parameters in step g).

[00154] Therefore, the distribution of the parameters p', w' at the end of step j) is different from the distribution of the same parameters that was used to calculate the operative water distribution during the execution of the step h).

[00155] There is, therefore, a step k) of repeating steps h) and i) previously described. [00156] In other words, following the reassignment of the distribution of the parameters p', w' it is possible to perform the calculation of a new operative water demand [step h)] this time based on the following factors:

- the new distribution of parameters p', w';

- the physical quantities measured in the subset of nodes and/or sides e).

[00157] The newly calculated operative water distribution is then compared [step i)] with the reference water distribution already calculated during step d).

[00158] If the differential emerging from this comparison is still higher than the predetermined threshold value, it is possible to assign a new distribution of the parameters p, w (herein referred to as p", w") and repeat steps h) and i) again using the distribution p", w" in the calculation of the operative water distribution.

[00159] This cycle of repeating of steps j) and h) and i) respectively will be performed until the calculation between the differential of the operative water demand distribution and the reference water demand distribution is lower than or equal to the threshold value. [00160] In this case, attention must be paid to the value of the parameters p, w suited to determine an operative water demand distribution which, in essence, approximates the reference water demand (i.e. has, with respect to the latter, a limited differential lower than the pre-set threshold value). [00161] In the present description, the parameters p, w with which a water demand distribution has been calculated that approximates the reference water demand distribution substantially accurately are referred to as pdef, Wdef.

[00162] As already described above, the calculation of the operative water demand distribution is based on the flow rate q_in, q_out of the initial node and the final node of the layout, and on the measurements made in a subset of nodes and/or sides of the layout that represent invariant factors with respect to all repetitions of the steps provided for during the execution of the method.

[00163] The parameters p, w represent the only factors that vary during the repetitive execution of step h).

[00164] The definition of a final distribution pdef, Wdef of parameters allows to approximate the current dynamic behaviour of the water network.

[00165] In this case, the distribution of the reference water demand is not affected by the presence of one or more leaks associated with the layout, and for this reason it is possible to consider it to be substantially constant over time.

[00166] However, when one or more water leaks occur at the nodes and/or sides of the layout, the dynamic behaviour of the entire water network changes compared to the ideal case, i.e. in the absence of leaks.

[00167] The final distribution of the parameters pdef, Wdef makes it possible to approximate the dynamic behaviour of the layout in the event of leakage occurs: these parameters pdef, Wdef, in fact, while defining a water demand distribution that is substantially equal to the reference distribution, have a trend that is affected by the new fluidic "set-up" associated with the water network when in the latter there are water leaks. [00168] In other words, at the end of the iterative procedure described by steps h) - I), the final distribution of the parameters p, w (here referred to as pdef, Wdef) is obtained, which is suited to simulate the reference water demand.

[00169] The analysis of the trend of final distribution of the parameters pdef, Wdef thus makes it possible to locate nodes and/or sides of the layout that are subject to leakage or in the proximity of which there is a water leak.

[00170] In essence, the final distribution of the parameters pdef, Wdef has peaks (compared to the average of their distribution) located at the areas of the layout where the leak is present.

[00171] Conveniently, the execution of step h) may be based on a mathematical operator p-Laplacian, i.e. a non-linear operator of the second order.

[00172] This operator makes it possible to approximate the fluidic behaviour of an aqueduct network by the use of variable parameters depending on the geometric and/or surface characteristics of the piping, connections, valves, etc. that make up such a network.

[00173] In the case of the present method, the p-Laplacian operator can be indicated as follows:

-V ■ (w^p~¹ \Vh\^p~²Vh') where the letter h refers to the piezometric height of the water flow at the layout nodes. The term q = (-WP~^ | 7i|p^-2 Vh) indicates the flow rate of the water flow circulating within the piping of the layout; in particular, the flow rate q is opposite to the gradient of piezometric height, and its circulation is directed from a node at higher piezometric height towards a node with a lower piezometric height.

[00174] In addition, it has been experimentally proven that the use of the p- Laplacian operator, which varies according to the parameters p, w associated with the geometrical and/or surface characteristics of the network elements, makes it possible to calculate a water demand whose distribution is very sensitive to the fluidodynamic variations occurring in the network itself (e.g. variations associated with water leaks).

[00175] Conveniently, to perform the calculation of the operative water demand using the mathematical operator p-Laplacian is required the definition of a specific pair of parameters p, w.

[00176] The parameter p indicates the exponent of the p-Laplacian operator.

[00177] In the context of calculating water demand in an aqueduct network, the distribution, at each node, of the parameter p has values varying between 1 ,3 and 1 ,9.

[00178] The other parameter w of the pair is suited to define a weight in the calculation of the p-Laplacian operator.

[00179] During the execution of step k), therefore, the variation of the exponent p and the weight w of the p-Laplacian operator is provided in order to determine the distribution of pdef, Wdef themselves such that to approximate the reference water demand.

[00180] An example of an application of the method described above is illustrated in the Figures.

[00181] In particular, Figure 1 illustrates the layout of a section of water network formed by nine nodes (node 0, node 1 ,...,node 8), where node 0 and node 8 correspond to the initial and final nodes of the layout respectively.

[00182] The water flow therefore travels through all intermediate nodes 1-7 according to a circulation from node 0 to node 8.

[00183] According to the present method, and as required in step c), the flow rates at node 0 (initial node - q_in) and at node 8 (final node - q_out) are known.

[00184] In addition, as is provided in step e), a physical quantity associated with water flow is measured at a subset of nodes.

[00185] In the case of the layout in Figure 1 , the water pressure is measured at node 2 and node 5. This measurement is indicated by the reference letters h2_mi_S and h5_mis.

[00186] The calculation of the water demand distribution in the layout schematize in Figure 1 is performed by using a p-Laplacian operator of the type described above. For this reason, it is necessary to define a distribution of the parameters p, w as required by step g) of the method.

[00187] Starting from the value of q_in, q_out, the measured value of h2_mis and h5_mis, and the initial definition of the parameters p, w associated with nodes 0 - 8 of the layout, it is possible to perform steps h) to I) iteratively in order to locate any leaks occurring along the layout development.

[00188] Assuming that the layout is leak-free (ideal situation), the iterative execution of the method steps results in a distribution of the variable w in the central nodes (node 2 - node 6) that is substantially constant and such to determine a trend substantially uniform. [00189] This condition is illustrated in Figure 2 in the diagram on the left.

[00190] It is now possible to assume the occurrence of a water leak in the layout of Figure 1. For example, this leak occurs at node 4 (indicated with an arrow).

[00191] Also in this case, the iterative steps of the method are performed from the knowledge of the flow rate values at node 0 and node 8 and the water pressure values measured at nodes 2 and 5 (q_in, q_out, h2_mis and h5_mis).

[00192] In the graph on the right of Figure 2, the trend of the final distribution of the parameter w (i.e. the trend of Wdef) in the various nodes of the layout can be seen when the leak is at the node 4.

[00193] As can be clearly seen from this diagram, the parameter Wdef no longer follows a uniform trend, but has a sharp downward peak at node 4.

[00194] In this way, observing the distribution of any peaks associated with the trend of the variable Wdef, it is possible to determine the parts of the layout where there is a water leaks.

[00195] Similar considerations can also be repeated for the parameter p.

[00196] According to a further aspect of the invention, a computer program is suited to implement the method described above.

[00197] Specifically, this computer program consists of a series of numerical instructions that can be stored in a digital memory and executed by a CPU provided in an electronic device such as a computer, tablet, smartphone or similar.

[00198] Following such processing, the CPU will be suited to control one or more peripheral display devices (e.g., a display, screen or the like) so as to make the data obtained as a result of the processing visible to the user.

[00199] Conveniently, the computer program object of the present invention has a set of instructions suited to implement all steps a) - 1) of the method described above in order to provide the user with information regarding the location of a possible water leaks occurring in a network (e.g. an aqueduct network).

[00200] The present program may also include instructions suited to also implement the sub-steps a¹) - a^v) of the method previously described in order to: remove any double/overlapping/excess piping from the layout; verify the presence of piping of the layout lacking connections; insert new piping/connections into the layout as necessary to provide continuity to the layout itself; insert in the layout the valves/pumps associated with the water supply network; establish the piezometric height value for each node of the layout.

[00201] In order to locate water leaks in layout of water supply network, it is possible to determine input data suited to be stored in digital memory and processed from the CPU. [00202] Specifically, input data is processed by the CPU according to the program instructions in order to provide output data containing information on the location of water leaks in the water supply network.

[00203] Output data are then processed by the CPU in order to be displayed on the display means provided with the user's electronic device (computers, smartphones, tablets, etc.).

[00204] In accordance with the method described above, the input data of the present computer program include, at least, the following information: knowledge concerning the water supply network (e.g. all the set of information of the network provided by the network authority); the water flow rates at the initial node and final node of a selected water network section in order to define the layout object to investigation; measurements of the physical quantities associated with the water flow measured at a subset of nodes belonging to such layout; the definition of a reference water demand distribution associated with the water supply network (and thus with the layout);

[00205] Starting from this input data (for which steps b), c), d) and e) of the previously described method were carried out), the instructions contained in the computer program object of the present invention allow the following steps to be carried out: arrangement of the layout of the water supply network in accordance with step a) of the method (including sub-steps a¹ ) - a^v ); definition of the parameters associated with the layout characteristics and preparation of a distribution of such parameters, as required in steps f) and g) of the method. Typically, the program instructions are suited to define the starting distribution of a pair of variables p, w;

- iterative process of calculating the final distribution of the parameters p, w (called pdef, Wdef) suited to define an operative water demand substantially coinciding with the reference water demand.

[00206] Through the above steps, the program reproduces steps a), f) - 1) of the method disclosed above.

[00207] Further instructions in the program are suited to locate water leaks in the layout according to the trend assumed by the final distribution of at least one of the parameters Pdef and Wdef.

[00208] In particular, these instructions make it possible to determine the presence of a leak when the value of one of these parameters at a given node of the layout has a peak (i.e. , significantly higher or significantly lower values) than its average value at the other nodes.

[00209] In this way, the program will be able to determine the node on the layout in the proximity of which there is a water leak.

[00210] The present invention can be carried out in other variants, all falling within the scope of the inventive features claimed and described herein; said technical features can be replaced by different technically equivalent elements and materials; the shapes and dimensions of the invention can be any as long as they are compatible with its use.

[00211] The reference numbers and signs included in the claims and in the description are only intended to make the text clearer to understand and must not be considered as elements limiting the technical interpretation of the objects or processes identified by them.

Claims

1 . A method for locating water leaks in a water supply network, wherein the water supply network has piping and connections, and is connected to one or more water utilities to which a water demand is associated, such method comprising the following steps: a) arrangement of the layout of the water supply network, said layout comprising a plurality of sides defined by piping and a plurality of nodes (0,...,8) defined by the connection points of two or more piping; b) definition of the initial node (0) and of the final node (8) of said layout; c) determination of the flow rate (q_iu) associated with the initial node (0) and the flow rate (q_ouy) associated with the final node (8) of said layout in the absence of water leaks; d) definition of the distribution of a reference water demand associated with the nodes (0,...,8) and/or sides of said layout in the absence of water leaks; e) measurement of one or more physical quantities (h2_Mis; hs_Mis) associated with the water flow circulating within a subset of nodes (2, 5) and/or sides of said layout; f) definition of one or more parameters (p, w) variable as a function of the geometric characteristics and surface properties associated with the piping and connections forming said nodes (0,...,8) and/or said sides of said layout; g) determination of a distribution of said one or more parameters (p, w) associated with said nodes (0,...,8) and/or said sides of said layout; h) determination of a distribution of operative water demand associated with the nodes (0,...,8) and/or the sides of said layout, said operative water demand being calculated as a function of the water rate (q_iu; q_ouy) of the initial node (0) and the final node (8) determined in said step c), of the distribution of said one or more parameters (p, w) determined in said step g), and of the value of said one or more physical quantities (h2_Mis; hs_Mis) measured in said step e); i) comparison between said distribution of operative water demand calculated in said step h) and the distribution of a reference water demand defined in said step d) to determine the differential between these two distributions of water demand; wherein, if said differential is greater than a predetermined threshold value the execution of the following steps is provided for: j) assignment of a new distribution of said one or more parameters (p’, w’) associated with the nodes (0,...,8) and/or to the sides of said layout; k) repetition of step h) and step i) by using the new distribution of said one or more parameters (p’, w’) assigned in said stepj); and wherein, if said differential is less than or equal to said predetermined threshold value, the execution of the following step is provided for: l) identification of one or more water leaks associated with the nodes (0,...,8) and/or the sides of said layout as a function of the trend of the distribution of said one or more parameters (p, w) used during the last execution of said step h).

2. Method according to claim 1 , characterized in that said one or more parameters (p, w) defined in said step f) is variable as a function of the diameter of the piping and/or connections defining the nodes (0,...,8) and/or the sides of said layout.

3. Method according to claim 1 or 2, characterized in that said one or more parameters (p, w) defined in said step f) is variable as a function of the length of the pipes and/or the connections defining the nodes (0,...,8) and/or the sides of said layout.

4. Method according to one or more of the preceding claims, characterized in that said one or more parameters (p, w) defined in said step f) is variable as a function of the roughness coefficient associated with the pipes and/or connections defining the nodes (0,...,8) and/or the sides of said layout.

5. Method according to one or more of the preceding claims, characterized in that said one or more parameters (p, w) defined in said step f) is variable as a function of the material used to manufact the piping and/or connections defining the nodes (p, w) and/or the sides of said layout.

6. Method according to one or more of the preceding claims, characterized in that said one or more parameters (p, w) defined in said step f) is variable as a function of the age associated with the piping and/or connections defining the nodes (0,...,8) and/or the sides of said layout.

7. Method according to one or more of the preceding claims, characterized in that in said step e) the measurement of the pressure associated with the water flow at said subset of nodes (2, 5) and/or sides is promoted.

8. Method according to claim 7, characterized in that it comprises a step m) of calculating the piezometric height associated with each node (2, 5) and/or side at which the water pressure is measured during the execution of said step e), said step h) of determining a distribution of operative water demand being variable as a function of the piezometric height calculated in said step m).

9. Method according to one or more of the preceding claims, characterized that the calculation of said operative water demand executed in said step h) is based on a non-linear second-order mathematical operator of the p-Laplacian type.

10. Method according to one of or more of the preceding claims, characterized in that a parameter (p) of said pair (p, w) defines the exponent of said non-linear second- order mathematical operator of the p-Laplacian type.

11 . Method according to one or more of the preceding claims, characterized in that the parameter (p) of said pair defining the exponent of said non-linear second-order mathematical operator of the p-Laplacian type has a value between 1 ,3 and 1 ,9.

12. Method according to claim 10 or 11 , characterized in that the other parameter (w) of said pair (p, w) defines a weight for the non-linear second-order mathematical operator of the p-Laplacian type.

13. Method according to one or more of the preceding claims, characterized in that the water leaks identified in said step I) are located at the nodes (0, ...,8) and/or sides of said layout wherein the distribution of said one or more parameters (p, w) has peak values deviating from the value of the same parameter (p, w) at the remaining nodes (0,...,8) of said layout.

14. A computer program comprising a plurality of instructions storable in a digital memory and executable in a CPU provided in an electronic apparatus, said instructions being suited to execute the steps of the method according to one or more of the preceding claims.