System for control of gas flow in a distribution network
Patent Information
- Application Number
- EP2024713731
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2023-03-16
- Filing Date
- 2024-03-14
- Publication Date
- 2026-01-21
AI Technical Summary
In methane gas distribution networks, gas leaks or breakages lead to irregular gas supply due to air bubbles forming downstream of maintenance intervention areas, potentially causing safety issues and requiring costly, time-consuming manual purging procedures to ensure safe gas reinstatement.
A system with flow diverter devices and sensors in each low pressure line, upstream of user meters, automatically monitors and regulates gas content, preventing air bubbles from reaching users by diverting insufficient gas flows into a vent duct, and can be remotely managed to control gas supply across the network.
Ensures safe and efficient gas supply by automatically blocking irregular gas flows, reducing the need for on-site personnel intervention during gas reinstatement and optimizing network management with real-time monitoring and control.
Smart Images
Figure IB2024052478_19092024_PF_FP_ABST
Abstract
Description
[0001] SYSTEM FOR CONTROL OF GAS FLOW IN A DISTRIBUTION NETWORK
[0002] TECHNICAL FIELD
[0003] The present invention fits into the technical sector which concerns methane gas distribution networks to private users or user outlets, such as civilian houses, shops, laboratories and commercial and industrial activities in general.
[0004] BACKGROUND ART
[0005] The transport of gas at high pressure is carried out by means of suitable pipes known to sector technicians as "backbones"; along said backbones there are first reduction stations which take a part of the high pressure gas and reduce its pressure to values between 5 and 12 bar, before conveying it into a series of pipes, or lines, downstream, defined as medium pressure pipelines.
[0006] Each medium pressure pipeline follows a pre-established path until it enters a second reduction station in which the gas undergoes a further pressure reduction to a value between 0.04 and 0.07 bar: a series of low pressure pipes, or lines, depart from said second station, which follow their own path and feed the various private users or user sockets. For brevity, the aforementioned private users and user sockets will be referred to below as "users".
[0007] According to a conventional classification, a distribution network, managed by a specific supply company, excludes the backbones and the first reduction stations, while it includes the related medium pressure pipelines, the second reduction stations from medium to low pressure and the low pressure pipelines until the latter arrive near the corresponding users.
[0008] More precisely, each low pressure pipe enters a meter with a valve, downstream of which a gas supply pipe begins towards the relevant user which then branches out to reach each piece of equipment to be served.
[0009] TECHNICAL PROBLEM
[0010] If gas leaks or breakages occur in the distribution network considered above, in a medium or low pressure pipeline, it is obviously necessary to interrupt the flow of gas in the affected pipeline in order to carry out maintenance work.
[0011] According to known technique, the flow block is obtained with suitable devices applied to the pipeline, upstream of the intervention area; downstream of the latter, the formation of air bubbles is frequent and when the gas flow resumes, they are carried forward making the gas supply flow irregular.
[0012] These air bubbles, almost inevitably, as they advance, reach the various users connected downstream and, therefore, enter the respective equipment, for example the burners of the hobs or the boilers, which may be operational at the moment.
[0013] If some equipment has an inefficient block valve, it may happen that the supply "hole" causes the flame that was lit to go out, but the flow of gas is not stopped once it flows again: the consequences are easily imaginable, and they can be catastrophic.
[0014] The awareness of these risks on the part of the supply company that manages the distribution network forces it to follow a prudential procedure after the supply of gas to the users that depend on the section of the network served by the pipeline under maintenance has been blocked: once the repair has been completed, in fact, before restoring the regular flow of gas, the Company's employees must personally carry out the operations which involve closing all the meters and carrying out the purging in each of the devices of each user, subject to agreements with the owners.
[0015] As is well understood, such a way of acting, although fully justified for safety reasons, is slow, expensive and very difficult even just to manage to organize the presence of each holder of the various users together with that of the employees.
[0016] OBJECTS OF THE INVENTION
[0017] The object of the present invention is therefore to propose a system for controlling the flow of gas in a distribution network, said system being structured so as to monitor the gas content compared to that of air in the flow brought to a user by the aforementioned distribution network, and to automatically prevent a mixture in which a gas content lower than a pre-established threshold reaches and enters the aforementioned user.
[0018] Another object of the invention consists in creating a system that has a capillary structure, capable of individually monitoring the entry of gas into each user of the distribution network, and capable of acting selectively to block the supply only to the users to which an irregular supply with air bubbles actually arrives.
[0019] Another object of the invention concerns the desire to obtain a system that is efficient regardless of which point of the distribution network the fault occurred, i.e. whether it concerns a low pressure pipeline or a medium pressure one.
[0020] A further object of the invention is to create a system in which each control and automatic blocking unit, associated with each user, can be connected to a remote management station, from which it is possible to obtain real-time information on the status of the entire system and also to send inputs containing operating instructions to each of said units.
[0021] Yet another object of the invention consists in proposing a system which can provide further control and automatic blocking units, in addition to those immediately upstream of the users, located in other critical points of the distribution network, or in intermediate points of the pipelines to be set up specially.
[0022] An additional object of the invention is to create a system whose construction and functional characteristics allow a supply company to organize a remote assistance service with the holders of the users of its distribution network, so in the event of a restart of the supply of gas after a blockage for repairs, direct access of the personnel on site to each of these users can be avoided.
[0023] SUMMARY OF THE INVENTION
[0024] These and other objects are fully achieved by means of a system for controlling the flow of gas in a distribution network, the latter being constituted by at least one medium pressure line, fed by a high pressure gas transport backbone through a first pressure reduction station, and at least one low pressure line, fed by said at least one medium pressure line through a second pressure reduction station interposed between the same medium and low pressure lines, with said at least one low pressure line pressure intended to transport the aforementioned gas up to the border of said distribution network, and to introduce it, without interruption, first into at least one meter with valve and then into an adduction pipe suitable for serving equipment belonging to a relevant user, the aforementioned system being designed to monitor the gas content with respect to that of air in the flow brought to said user by the aforementioned distribution network and to prevent a mixture in which a gas content lower than a pre- established threshold reaches said user.
[0025] The system includes:
[0026] - a flow diverter device for each of said users, arranged in the terminal section of said at least one low pressure line, immediately upstream of a corresponding meter with valve, the same flow diverter device being designed to assume, alternatively, two characteristic configurations, the first of which being a regular supply, in which the gas flow, with a correct saturation level, is directed from said low pressure line to the aforementioned private supply pipe; and a second purge configuration, in which the gas flow, with an insufficient saturation level, is closed to the user and directed into a vent duct for discharge into the atmosphere;
[0027] - at least one sensor for measuring the gas content in the gas flow carried by said distribution network, arranged in the aforementioned low pressure line immediately upstream of said flow diverter device;
[0028] - operating members, associated with said flow diverter device, for switching it from the aforementioned first regular supply configuration to the second purge configuration and vice versa;
[0029] - a control unit, designed to receive the reading of the aforementioned at least one sensor and to provide the activation command of the said actuating members, for the aforementioned switching of the said flow diverter device in one or the other of the aforementioned characteristic configurations.
[0030] BRIEF DESCRIPTION OF THE DRAWINGS
[0031] The characteristic features of the subject invention will be evident from the following description of the subject system for controlling the flow of gas in a distribution network, in accordance with what is proposed in the claims and with the aid of the attached drawing tables, in which:
[0032] - Fig. 1 illustrates a schematic view of a distribution network and the subject system, in a preferred embodiment;
[0033] - Fig. 2A schematically illustrates, on an enlarged scale, a fundamental component of the system of Fig. 1 , in a first embodiment and in a first operational configuration;
[0034] - Fig. 2B illustrates the component of Fig. 2A, in a second operational configuration;
[0035] - Fig. 3A schematically illustrates a second embodiment of the component of Fig. 2A, in a corresponding first operational configuration;
[0036] - Fig. 3B illustrates the component of Fig. 3A, in a second operational configuration;
[0037] - Fig. 4 illustrates, in a schematic view similar to Fig. 1 , a modified version of the system;
[0038] - the Figs. 5A, 5B illustrate, similarly to Figs. 2A, 2B, the two operational configurations of a further similar component applied at another point of the distribution network.
[0039] DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION
[0040] In the figures listed above, the reference 1 indicates, as a whole, the system which is the object of the present invention.
[0041] System 1 is designed to control the flow of gas, usually methane gas, transported in a distribution network R, in particular to monitor the gas content compared to that of air present in the pipes, as better described below.
[0042] The distribution network R, in a known way, is fed by a high pressure gas transport backbone D, through a first pressure reduction station C1 , which delivers gas at a pressure usually between 5 and 24 bar, which is considered by the workers to be medium pressure.
[0043] As already mentioned in the introduction, a distribution network R is conventionally made up of at least one medium pressure line MP, fed by the first substation C1 , and by at least one low pressure line LP, located downstream of the first and fed through a second pressure reduction substation C2, placed between the same medium and low pressure lines MP, LP.
[0044] The second station C2 further reduces the gas pressure to values between 1 .5 and 0.04 bar, before introducing it into the aforementioned at least one low pressure line LP.
[0045] Each low pressure line LP, in turn, is intended to transport the aforementioned gas up to the border of said distribution network R, where there is at least one meter K with a closing / opening valve, of a known type and therefore not illustrated in detail, which introduces it, without interruption, into a supply pipe Y suitable for serving equipment (not shown, for example burners in hobs, boilers and the like) pertaining to a relevant user U, for example a home, or users U with other equipment, present in commercial or industrial activities.
[0046] System 1 , as will be evident in the following description, guarantees that in the gas flow brought to each user U served by the distribution network R the gas content compared to the air content is equal to or greater than a certain minimum percentage threshold, indicatively between 65-70%. Otherwise, a mixture with an insufficient gas content is prevented from entering the pipes of each user U, for the reasons mentioned in the introduction.
[0047] The system 1 , in a preferred embodiment according to the invention (Fig. 1 ), includes for each of said users U a flow diverter device 2, arranged in the terminal section of said at least one low pressure line LP, immediately upstream of the corresponding meter with valve K. Each of said flow diverter devices 2 is designed to assume, alternatively, two characteristic configurations: a first one of which of regular supply G, in which the gas flow, with a correct saturation content, is directed by said low pressure line LP to the aforementioned private supply pipe Y, through the meter K; and a second purge configuration S in which the gas flow, with an insufficient saturation content, is closed to the user II and directed into a vent pipe for discharging into the atmosphere.
[0048] In a first embodiment, shown in Figs. 2A, 2B, said flow diverter device 2 is made up of a pair of linear solenoid valves of the on / off type, with a first solenoid valve 21 associated with said low pressure line LP, immediately downstream of the branch from which said flow duct vent X departs, and a second solenoid valve 22 associated with this latter.
[0049] Each solenoid valve 21 , 22 is provided with respective actuation members, not illustrated in detail as they are of a known type, for switching it from the aforementioned first regular supply configuration G (Fig. 2A) to the second purge S (Fig. 2B ) and viceversa.
[0050] In a second embodiment, as shown in Figs. 3A, 3B, said flow diverter device 2 consists of a three-way solenoid valve 23, associated with said low pressure line LP at the branch from which said vent duct X departs.
[0051] The measurement of the gas content is entrusted, for each user U, or for each flow diverter device 2, to at least one sensor 3, arranged in the aforementioned low pressure line LP immediately upstream of the same flow diverter device 2.
[0052] With a flow diverter device 2 with two linear solenoid valves 21 , 22, the aforementioned sensor 3 for measuring the gas content is positioned upstream of the first 21 and second solenoid valves 22, substantially at the point of intersection between said low line pressure LP and the aforementioned vent pipe X (Figs. 2A, 2B). With a flow diverter device 2 to a three-way solenoid valve 23, said sensor 3 is positioned immediately upstream of the same three- way solenoid valve 23 (Figs. 3A, 3B).
[0053] In both embodiments described, the flow diverter device 2 is associated with a control unit 4, designed to receive the reading of the relevant sensor 3 and to provide the activation command of said actuating members, in a manner compliant with switching said flow diverter device 2 in one or the other of the aforementioned characteristic configurations G, S.
[0054] When the flow diverter devices 2 are of the type with two linear solenoid valves 21 , 22, each control unit 4 includes a phasing device, preferably of the electronic type and therefore not illustrated in detail, suitable for controlling the aforementioned switching from the first configuration of regulate supply G to the second purge S by selectively activating, with a time difference, first the actuating members of the first solenoid valve 21 , for its closure, and then the actuating members of the second solenoid valve 22 for the opening of the aforementioned vent duct .
[0055] Obviously, this phasing device acts with the opposite time difference to control the reverse switching, from the second purge configuration S to the regular supply configuration G of the flow diverter device 2.
[0056] Advantageously, in system 1 a remote management station 5 can be provided, connected by radio frequency with all the control units 4, designed to receive the respective readings of its sensor 3 from the latter and to send them to the same control units 4, selectively, enabling or disabling inputs, inherent to carrying out the aforementioned switching of the corresponding flow diverter devices 2.
[0057] The operation of the preferred embodiment of system 1 , which can already be largely deduced from what has just been said, is described with reference to a single user II, or to a single automatic control and blocking unit formed by a flow diverter device 2, a sensor 3 and a control unit 4, as each is independent of the other, but in practice it is absolutely clear that a plurality of users II and therefore of respective control and automatic blocking units can be affected simultaneously.
[0058] Therefore, as anticipated in the introduction, if gas leaks or breakages occur in the distribution network R considered above, in a medium MP or low pressure LP pipeline, it is necessary to interrupt the gas flow in order to carry out the maintenance intervention.
[0059] Downstream from the intervention area, air bubbles frequently form in the pipes, which are pushed forward when the gas flow resumes: as intuitively understandable, areas are created in which the gas content is low and easily drops to below the aforementioned minimum threshold of 65-70%.
[0060] When one or more sensors 3 detect such an insufficient gas content in the flow, the control unit(s) 4 promptly and automatically activate the switching of the relevant flow diverter devices 2 from the first configuration of regular supply G to the second purge valve S, thus blocking the flow of gas to the meter with valve K.
[0061] This prevents an irregular gas supply from reaching some equipment of a user II, with an inefficient block valve, which could cause the previously lit flame to go out.
[0062] The remote management station 5 is informed in advance to which users II the supply is suspended to carry out the repair of the distribution network and, once the repair is completed, it can remotely enable the resumption of the gas supply by opening the relevant devices flow diverters 2: in those users II to which the aforementioned air bubbles arrive, system 1 is able to block again, and immediately, the flow of non-compliant gas, before it enters the meter K and the user II itself.
[0063] In real time, the same remote management station 5 receives the notification of the users II once again blocked, allowing the supply company to prepare the appropriate actions so that they too can receive the gas in complete safety.
[0064] With these construction and functional characteristics, system 1 can allow a provider to organize a remote assistance service with the holders of the users of its distribution network, for a guided purge of the respective equipment, when the gas supply is restarted after a blockage due to repairs.
[0065] It would thus be possible to avoid the direct access of the on-site personnel to each of these users.
[0066] However, if the safety standards currently in place, not yet known about this system 1 , prevent such a way of proceeding, it is possible at least to limit the access of personnel to the II utilities, for purging the equipment, to only those that have suffered the presence of air bubbles with a sudden new blockage after the repair.
[0067] Fig. 4 illustrates a modified version of system 1 , which in addition to what has already been described, located in each low pressure line LP, includes, in said at least one medium pressure line MP, a second flow diverter device 20, arranged immediately upstream of said second pressure reduction station C2, placed between the aforementioned medium MP and low pressure LP lines.
[0068] The same second flow diverter device 20 is also intended to assume, alternatively, the two characteristic configurations already mentioned; i.e. a first of regular supply G (Fig. 5A), in which the gas flow, with a correct content of saturation, is directed from the medium pressure line MP to the second station C2 and from this to the aforementioned at least one low pressure line LP; and a second purge configuration S (Fig. 5B) in which the flow of gas, with an insufficient content of saturation, entry into the aforementioned second station C2 is prevented and directed into a respective second vent duct X2 for discharge into the atmosphere.
[0069] Similarly to what has already been said, the second flow diverter device 20 is associated with:
[0070] - a second sensor 30 for measuring the gas content, arranged in the aforementioned medium pressure line MP immediately upstream of the same second flow diverter device 20;
[0071] - actuation members, for switching the same second flow diverter device 20; a second control unit 40, designed to receive the reading of the aforementioned second sensor 30 and to provide the activation command of said actuation members.
[0072] Said second flow diverter device 20 has been illustrated in Figs. 5A, 5B, of the type with two linear solenoid valves 21 , 22, like the one in Figs. 2A, 2B, but it is obvious that it is possible to envisage the use of a three-way valve like the one visible in Figs. 3A, 3B.
[0073] Also the aforementioned second automatic control and block unit, located in the medium pressure area and formed by the second flow diverter device 20, the second sensor 30 and the second control unit 40, is advantageously interfaced with the aforementioned remote management station 5, which is suitably equipped to combine the action of the flow diverter devices 2, placed at the edge of the distribution network R, upstream of the meters K, with the intervention of the aforementioned second flow diverter device 20.
[0074] In addition to what has been said so far, the system in question can be equipped with additional control and automatic blocking units, in addition to those immediately upstream of the utilities and those before the medium to low pressure reduction stations, located in other critical points of the distribution network, or at intermediate points of the pipelines to be specially prepared.
[0075] From the above, the advantageous aspects of the system proposed with the present invention are clearly evident, and it is clear that they are certainly very attractive for the supply companies that manage the methane gas distribution networks.
[0076] The system, in fact, allows the gas content to be kept under constant control with respect to that of air in the flow carried by the distribution network towards the users, intervening automatically to block the flow to the latter when a gas content lower than a pre- established minimum threshold, due for example to the presence of air bubbles in the pipes.
[0077] It is important to underline how the system has been advantageously designed to have a capillary structure, capable of individually monitoring the entry of gas into each user of the distribution network, and capable of acting selectively to block the supply only to the users to which it reaches actually irregular feeding with air bubbles.
[0078] The fact that the monitoring of the gas content is carried out just upstream entering each user makes the system very efficient and safe, regardless of where in the distribution network the problem originated.
[0079] A further advantageous feature of the invention consists in having provided a remote management station to which data can flow from each peripheral control and flow blocking unit, so as to have real-time information on the status of the entire system, optimizing management, of the operating instructions to be sent.
[0080] The implementation variant of the system which provides additional controls of the gas content, upstream of the capillary ones before the user meters, which expand the functionality and efficiency of the system and can be better adapted depending on the size and conformation of the network distribution.
[0081] Yet another object of the invention consists in proposing a system which can provide further control and automatic blocking units, in addition to those immediately upstream of the users and those at the entrance to the medium to low pressure reduction stations, located in other points critics of the distribution network. The characteristic features of the system allow a supply company to organize a remote assistance service with the holders of the users of its distribution network, so that in the event of restarting the gas supply after a blockage for repairs, direct access can be avoided from the personnel assigned on site to each of these users, with evident and conspicuous savings in time and costs.
[0082] However, it is understood that what has been described above has an illustrative and non-limiting value; therefore any variations in detail that may be necessary for technical and / or functional reasons are considered from now on to fall within the same protective scope defined by the claims below.
Claims
CLAIMS1 . System for controlling the gas flow in a distribution network (R), this latter being made up of at least one medium pressure line (MP), fed by a backbone (D) for transporting the high pressure gas through a first pressure reduction station (C1 ), and at least one low pressure line (LP), fed by said at least one medium pressure line (MP) through a second pressure reduction station (C2) interposed between the same medium pressure lines (MP) and low pressure (LP), said at least one low pressure (LP) line being fit to transport the gas up to the periphery of said distribution network (R), and to introduce it, without interruption, first into at least one meter (K) and therefore in a supply pipe (Y) suitable for serving equipment pertaining to a relevant private user or user socket (U), the aforementioned system (1 ) being envisaged to monitor the gas content with respect to that of air in the flow brought to said user (U) by the aforementioned distribution network (R) and prevent a mixture in which a gas content lower than a pre-established threshold, indicative of the presence of one or more air bubbles, is entered into the aforementioned user (U), the same system (1 ) being characterized in that it includes:- a flow diverter device (2) for each of said users (U), arranged in the terminal section of said at least one low pressure line (LP), immediately upstream of a corresponding meter (K) with valve, the same diverter device of flow (2) being foreseen to assume, alternatively, two characteristic configurations, one of which before regular supply (G), in which the gas flow, with a correct saturation level, is directed by said low pressure line ( LP) to the aforementioned private supply pipe (Y), and a second purge configuration (S) inwhich the gas flow, with an insufficient saturation level, is closed to the user (II) and directed into a vent pipe (X) for discharge into the atmosphere;- at least one sensor (3) for measuring the gas content in the gas flow carried by said distribution network (R), arranged in the aforementioned low pressure line (LP) immediately upstream of said flow diverter device (2);- operating members, associated with said flow diverter device (2), for switching it from the aforementioned first regular supply configuration (G) to the second purge configuration (S) and vice versa;- a control unit (4), designed to receive the reading of the aforementioned at least one sensor (3) and to provide the activation command of said actuating members, for switching said flow diverter device (2) in one or the other of the aforementioned characteristic configurations (G, S).
2. System according to claim 1 , characterized in that said flow diverter device (2) is made of a pair of linear solenoid valves (21 , 22) of the on / off type, each provided with respective actuation members, a first solenoid valve ( 21 ) being associated with said low pressure line (LP), immediately downstream of the branch from which said vent duct (X) departs, and a second solenoid valve (22) associated with the latter, and in that said at least one sensor (3) for measuring the gas content is positioned upstream of said first and second solenoid valves (21 , 22), substantially at the point of intersection between said low pressure line (LP) and said vent duct (X) .
3. System according to claim 2, characterized in that said control unit (4) includes a phasing device, suitable for controlling the aforementioned switching from the first regular supplyconfiguration (G) to the second purge configuration (S) by operating selectively, with difference temporal, first the actuation members of said first solenoid valve (21 ), for its closure, and then the actuation members of said second solenoid valve (22) for opening the aforementioned vent duct (X), as well as for controlling the reverse switching, from the second purge configuration (X) to the regular supply configuration (G), of the aforementioned actuating members of the second (22) and the first solenoid valve (21 ) with opposite time difference.
4. System according to claim 1 , characterized in that said flow diverter device (2) is made of a three-way solenoid valve (23), associated with said low pressure line (LP) at the branch from which said vent duct (X), and in that said at least one sensor (3) for measuring the gas content is positioned immediately upstream of said three-way solenoid valve (23).
5. System according to claim 1 , characterized in that a remote management station (5) is provided, connected by radio frequency means with said control unit (4), designed to receive from the latter the reading of the aforementioned at least one sensor (3) and for sending to the same control unit (4) enabling or disabling inputs relating to carrying out the aforementioned switching of the flow diverter device (2).
6. System according to claim 1 , characterized in that in said at least one medium pressure (MP) line the following are provided: a second flow diverter device (20), arranged immediately upstream of said second station (C2) for pressure reduction, interposed between the aforementioned medium (MP) and low pressure (LP) lines, the same second flow diverter device (20) being also intended to assume, alternatively, two characteristic configurations, a first one of which being of regular supply (G ),in which the gas flow, with a correct saturation level, is directed from said medium pressure (MP) line to the aforementioned second pressure reduction station (C2) and from this to the aforementioned at least one low pressure line ( LP); and a second purge configuration (S) in which the gas flow, with an insufficient saturation level, is prevented from entering said second station (C2) and directed into a respective second vent duct (X2) for discharge into the atmosphere; at least a second sensor (30) for measuring the gas content in the gas flow carried by said distribution network (R), arranged in the aforementioned medium pressure (MP) line immediately upstream of said second flow diverter device (20); operating members, associated with said second flow diverter device (20), for switching it from the aforementioned first regular supply configuration (G) to the second purge configuration (S) and vice versa; a second control unit (40), designed to receive the reading of the aforementioned at least one second sensor (30) and to provide the activation command of said actuating members, for the aforementioned switching of said second flow diverter device (20) in one or the other of the aforementioned characteristic configurations (G, S).
7. System according to claim 1 or 6, characterized in that a remote management station (5) is provided, connected by radio frequency means with said control units, first (4) and second (40), designed to receive the readings from the latter of the aforementioned at least one sensor, first (3) and second (30), concerning the gas content present respectively in said at least one low pressure line (LP) and at least one medium pressure line (MP), and for sending to one or both of said control units, first (4) and second (40), with respective enabling or disablinginputs, inherent in carrying out the aforementioned switching of the corresponding flow diverter device, first (2) and second (20).