FLUID METER, ESPECIALLY GAS METER, WITH LOW PRESSURE ABSORPTION

Description

FLUID METER, IN PARTICULAR GAS METER, A REDUCED PRESSURE ABSORPTION DESCRIPTION TECHNICAL FIELD 5 The present invention relates to fluid meters, such as gas meters or water meters, and methods for updating the software components of meters installed on site. More specifically, the invention refers to a counter according to the preamble of claim 1. STATE OF THE ART 10 Gas measuring devices (meters) are widely used from the fuel gas industry to monitor the amount of gas consumed both from domestic users and from commercial and industrial users. A meter installed on a branch of a distribution network represents always an obstacle to the flow of fluid. Consequently, the meters 15 cause a phenomenon called “pressure absorption”, also referred to in the industry as the “pressure drop” of the meter. The absorption of pressure is a piece of data that characterizes each meter, and which the installer must take into account when installing and starting up the meter. The pressure loss depends from the flow of gas flowing through the meter, in particular, increases 20 as the flow rate increases following a peculiar curve for the given counter. In general, the total pressure absorption of a meter is determined from the sum of the absorption due to the fluid dynamic resistance and that due to mechanical resistance. The first is essentially due to the 25 turbulences inherent in the passage of a gaseous fluid through an instrument fluid-dynamically inefficient, while the second is due to friction and inertia of any moving mechanical parts. Considering the counters gas meters equipped with thermo-massive sensors, these meters are characterised by the total absence of mechanical elements in motion or subjected to elastic deformation 30 (e.g. gears, diaphragms), therefore the pressure absorption in this type of meters is determined solely by the absorption due to the resistance fluid dynamics. The pressure drop must be kept within predetermined maximum values, in order to ensure correct and efficient functioning of the network 35 fluid distribution. In this regard, various national laws and regulations international standards, such as the EN 17526:2021 standard and Directive 2014 / 32 / EU of the European Parliament and of the Council of 24 February 2014, define the constraints that every gas meter must satisfy in order to be sold on the market and installed in the local gas network. In the art, in order to reduce the pressure absorption in a meter of the a-type 5 membrane JP 6584872 proposes to round off the corners or edges formed by adjacent walls inside the meter, so that when flowing from one to the other of the two walls the gas does not stagnate in the vicinity of the junction between the walls (if angle), or follow the change in path more continuously determined by the joint between the walls (if corner). 10 In the case of meters with thermo-mass sensors, the Applicant has determined that this kind of solution does not constitute a guarantee of obtaining the required requirements. In fact, meters with thermo-massive sensors, despite not having of elements subject to movement or elastic deformation which may cause mechanical resistances, they are equipped with an element generally indicated 15 as a “flow linearizer” necessary for optimal operation of the thermo-massive sensor but capable of determining significant resistances of the type fluid dynamics. For example, document CN 208833306 describes a “device rectifier” inserted, as an additional element, inside the compartment of the 20 counter, connected to the inlet nozzle. This device is characterized by a double function: to slow down part of the incoming gas, and to filter solid particles or impurities present in the gas fed into the meter. This rectifier device It essentially consists of a cylindrical tube or duct, inside which is a smaller duct was inserted coaxially. The internal duct 25 has a truncated conical cavity and an external profile characterised instead by a “protrusion” or diametrical enlargement, which develops along the entire cross-section of the internal duct. A portion of the gas flow coming from from the inlet nozzle of the meter is subject to a reduction in speed, due to the progressive increase in the pipe cross-section. The reduction in speed 30 of the portion of the gas flow passing through the central section determines a "stabilization" of the gas flow that passes through the meter compartment and then continues to reach the outlet nozzle. However, the remaining part of gas passes through the constriction defined between the body of the internal duct and the internal surface of the cylindrical structure that encloses the whole, and is subject to 35 an increase in speed. Furthermore, the meeting of the fronts of the two portions of flow of gas at different speeds generates turbulence. As a result, the rectifier device of CN 208833306 does not allow to reduce or control pressure drops associated with the meter in which it is installed. on the contrary, the generation of turbulence near the device outlet rectifier can exacerbate the pressure drop problem. Furthermore, US 2020 / 056916 describes a gas meter comprising a body. The 5 gas meter also includes a flow measurement unit arranged inside the body. The flow measurement unit has a measuring flow passage with a straight tubular shape and equipped with an inlet opening and an outlet opening through which the fluid passes measure, and a shut-off valve positioned in an extended section that 10 extends from the outlet opening of the gas meter body to its interior. The input port of the measuring unit is hermetically connected to the extended section so that they are in fluid communication. US 2019 / 003868 describes a gas meter with an accessible hollow body via inlet and outlet openings and a shielding plate located at 15 a predetermined distance from a meter input opening. Furthermore, The gas meter includes a flow meter that measures the flow rate of the fluid and a connecting element that connects the output of the meter to each other flow rate and the outlet of the meter. In addition, the inlet of the meter, the plate shielding, the flow meter, the connection element and the outlet of the 20 counters are positioned linearly in this order. JP 2021 / 117215 describes an ultrasonic flow meter equipped with a input pass separated from an input buffer region by a first dividing wall that projects toward the inner face of a meter body. A central hollow part of the body houses a measuring unit arranged between the 25 input buffer region and one output buffer region. The unit of measurement comprises a tubular body equipped with inlet and outlet openings in which a fluid flow occurs between the inlet passage and the outlet passage of the meter. JP 2021 / 105545 describes an ultrasonic gas meter comprising a 30 plurality of measuring tubes, wherein the measurement accuracy of the gas flow rate can be increased by stabilizing the flow of the flowing gas inside or outside each measuring tube. The ultrasonic gas meter includes a gas inlet, a gas outlet, a plurality of measuring tubes tubular shape connecting an inflow lung and an outflow lung, 35 flow measurement units for measuring the gas flow rate of the pipes measuring, and a plurality of rectifier plates located in at least one of the inflow lung or outflow lung. JP 2017 / 129391 describes an ultrasonic gas meter equipped with a filter formed by a cylindrical element, having an external circumferential shape which corresponds to the surface of the internal wall of a flow path in entrance, and a terminal wall that extends continuously at one end 5 of the cylindrical element and equipped with an opening which constitutes a passage of gas. The filter is held in place by the surface of the inner wall of the inlet flow path. JP H 0669748 describes a flowmeter in which a unit of measurement for the flow measurement is housed in a box-like casing, and on the surface 10 There is a switch on the front of the case. The switch on the unit measurement is directed towards an actuating organ to be operable by the itself without the use of intermediate connecting elements. The proposed structures offer gas meters with flow meters equipped with structures that require the passage of the flow of gas to be measured 15 within a duct in which measuring equipment is positioned. These solutions are aimed at improving the measurement of the flow rate of the gas passing through the gas meter. However, these solutions are not suitable for limiting effectively absorbs pressure associated with the gas flow through the counter. In other words, the Applicant noted the lack of solutions in 20 degree of limiting the pressure absorption within desired values, such as values imposed by the above-mentioned regulations, in particular in the case of gas meters designed to operate with flow rates greater than 10 scm / h. As is known, scm indicates “standard cubic metre”, which is a measure of the quantity of fluid – typically, air - contained in a volume of one cubic meter m / h under reference conditions 25 notes. In accordance with the above-mentioned regulations, the flow rates of the meters gas, even though such meters are typically intended for use with gas fuels, are still measured using a flow of air characterized by a density equal to 1.2 kg / m (corresponding to a temperature of 20 °C and a pressure of 1.01325 10 Pa – i.e., 1.01325 bar). 30 PURPOSES AND SUMMARY OF THE INVENTION It is the purpose of the present invention to overcome the drawbacks of the art Note. In particular, it is an object of the present invention to provide a meter of a quantity of fluid that passes through a hydraulic network, for example a 35 gas meter, characterized by a limited pressure loss through a simple and efficient solution. A further object of the present invention is to propose a meter of fluid, for example a gas meter with flow rates greater than 10scm / h, equipped with a fluid dynamic element suitable for regulating the flow of fluid in input in order to limit the pressure loss of the gas meter. 5 These and other objects of the present invention are achieved by means of a system incorporating the features of the attached claims, which form an integral part of this description. According to a first aspect, the present invention is directed to a meter of fluid, preferably a gas meter, comprising a hollow body 10 box having a maximum flow rate greater than 10 scm / h, which delimits a measuring compartment. An inlet duct and an outlet duct allow for fluid flow inside and outside the measuring compartment. A separator assembly included in the measuring compartment measure. The separator assembly is suitable for defining an input region, suitable 15 to receive the flow of fluid entering the measuring compartment through the conduit inlet, and an outlet region, suitable for receiving the flow of fluid exiting from the measuring chamber through the outlet duct. Furthermore, the separator assembly comprises at least one opening adapted to permit a flow of fluid between the input region and output region. Measuring means are arranged 20 within the entry region in order to provide an indication of a quantity of fluid passing through the fluid meter. The means of measurement comprise at least one measuring conduit coupled to said at least an opening of the separator assembly. Advantageously, the fluid meter comprises an element 25 fluid dynamics arranged in the outlet region. The fluid dynamics element comprising an inlet opening, coupled to the assembly opening separator, and a free outlet opening. The surface of the outlet opening It has a substantially oval shape and is larger than the surface of the opening entrance, which has a substantially circular shape. 30 The fluid meter according to the present invention allows to measure in reliably the amount of fluid passing through the fluid meter (i.e., the amount of fluid supplied to a user) and at the same time ensures a low pressure absorption, in particular equal to or less than the limits imposed by the directives currently in force regarding gas distribution. 35 These goals are achieved with a compact and robust solution, which can be built through production techniques typically consolidated in the sector. Therefore, the fluid meter according to the invention can also be manufactured in large volumes in an economical way. In one embodiment, a ratio of the surface area of ​​the outlet opening and the inlet opening of the fluid dynamic element is between approximately 1 and about 2.2, preferably between about 1.2 and about 2. In one embodiment, the surface of the outlet opening and the opening 5 of the fluid dynamic element input lie on substantially planes parallel and are spaced from each other by a distance of approximately 24 mm to approximately 70 mm, preferably between approximately 29 mm and approximately 64 mm. In one embodiment, the fluid dynamic element has a structure asymmetrical flared. Preferably, a tubular body of the element 10 fluid dynamics has a curved portion, which has a lateral section profile defined by a first radius of curvature between approximately 25 mm and approximately 45 mm, preferably between about 30 mm and about 40 mm, along a direction of main development of the exit opening. Even more preferably, a further curved portion of the tubular body has a 15 lateral section profile defined by a further radius of curvature included between approximately 80 mm and approximately 105 mm, preferably between approximately 86 mm and approximately 100 mm In one embodiment, the outlet opening of the fluid dynamic element It faces a wall that delimits the exit region. In particular, the outlet opening is at a distance of approximately 15 mm to approximately 60 mm, 20 preferably between about 20 mm and about 55 mm from the wall delimiting the region of exit. In one embodiment, the outlet opening of the fluid dynamic element comprises a first lobe, defined by a first radius of curvature of the lobe, and a second lobe, defined by a second lobe radius of curvature. 25 Preferably, the first radius of lobe curvature is smaller than the second radius of lobe curvature. Furthermore, the first lobe and the second lobe of the aperture are at a first distance and a second distance, respectively, from the duct fluid meter outlet. Advantageously, the first distance is less at the second distance. 30 The dimensions and / or ratios according to the various embodiments have been identified by the Applicant as optimal for the purpose of reducing absorption of pressure associated with the fluid meter. In one embodiment, the fluid dynamic element comprises a tubular body and at least one separating wall (or separator, or lamella) 35 extending inside the tubular body. The separating wall divides the volume delimited by the tubular body in at least two ducts. Preferably, the separating wall has a lateral cross-section profile defined by a radius of curvature equal to or less than the first radius of curvature and / or equal or greater than the second radius of curvature. The separating walls and, in particular, the ducts defined by them and by the body 5 tubular of the fluid dynamic element allow to obtain a distribution of the more homogeneous gas flow inside the fluid dynamic element, which reduces turbulence, even at high flow rates. In one embodiment, the separator assembly comprises a body box-shaped housing inside the measuring compartment. In this case, the region of 10 The entrance and exit region are delimited by the box body and a wall arranged inside the box-shaped body. In addition, an inlet opening of the body box-shaped allows the fluid flow to access from the measuring compartment to the region of entrance. Otherwise, an additional outlet duct of the separator assembly It is coupled to the gas meter outlet pipe so that only the fluid 15 inside the outlet region can leave the fluid meter. Optionally, the fluid meter comprises a plurality of assemblies separators. In this case, the box body of each separator assembly houses a respective measuring conduit and a respective element fluid dynamics. 20 Each box body and wall forms a damper (or conveyor of flow) which directs the incoming gas flow towards the measuring means and the diffuser. In particular, the shape of the box-shaped body can be designed to further limit turbulence in the fluid flow. Furthermore, arrange more than a box-shaped body inside a measuring compartment allows the division of the 25 fluid flow between multiple measuring lines and multiple fluid dynamic elements, thereby obtaining a more effective measurement of fluid flow and an efficient reduction pressure drops even in the case of particularly high flow rates. In one embodiment, the separator assembly comprises a septum arranged in the measuring compartment, which is suitable for separating the measuring compartment into the region of 30 entry and exit region. This embodiment of the fluid meter is particularly simple and economical, without negatively affecting the measurement of the fluid flow or on the reduction of pressure drops. Optionally, the partition comprises a plurality of openings suitable to allow 35 a fluid flow between the inlet region and the outlet region. In this case, a respective measuring conduit and a respective fluid dynamic element are coupled to each opening of the plurality of openings. Even in this embodiment, excellent performance is achieved even in the case of particularly high fluid flow rates. Further features and objects of the present invention will appear. 5 made clearer by the following description. BRIEF DESCRIPTION OF THE DRAWINGS The invention will be described below with reference to some examples, provided for explanatory and non-limiting purposes, and illustrated in the attached drawings. These drawings illustrate different aspects and embodiments of the present invention. 10 invention and, where appropriate, reference numerals illustrating structures, similar components, materials and / or elements in different figures are indicated by similar reference numbers. Figure 1 is an axonometric view of a gas meter in a form of carrying out the present invention; 15 Figure 2 is an axonometric sectional view of the gas meter in Figure 1 with respect to a section plane Π; Figure 3 is an exploded isometric view of a flow conveyor according to an embodiment of the present invention included in the gas meter of Figure 1; 20 Figure 4 is a side sectional view of the fluid flow conveyor of Figure 3, without a fluid conduit, with respect to the section plane Π; Figure 5A is a front view of a fluid dynamic element according to a embodiment of the present invention included in the measurement module of Figures 3 and 4; 25 Figure 5B is a side sectional view of the fluid dynamic element of Figure 5A along a plane of section PP; Figure 5C is a rear view of the fluid dynamic element of Figure 5C, and Figure 6 is a side sectional view of a fluid dynamic element according to a different embodiment of the present invention, and 30 Figure 7 is a side sectional view of a gas meter according to a alternative form of the present invention. DETAILED DESCRIPTION OF THE INVENTION Some preferred embodiments will be described below in detail, although the invention is susceptible to various alternative modifications. must be understood, however, that there is no intention to limit the invention to the specific embodiment illustrated, but, on the contrary, the invention is intended to cover all modifications and / or use of elements or steps 5 equivalents that fall within the scope of the invention as defined in the Unless otherwise defined, all terms of art, notations and other terms scientific terms used here are intended to have the meanings commonly understood by those skilled in the art to which this description refers 10 belongs. In some cases, terms with commonly understood meanings are defined here for clarity and / or ready reference; the inclusion of such definitions in this description should therefore not be construed as representing a substantial difference from what is generally included in art. 15 The terms “comprising”, “having”, “including” and “containing” are to be be understood as open terms (i.e., the meaning “including, but not limited to”) and are to be considered as a support also for terms such as “consisting essentially of”, “essentially consisting of”, “consisting of” or “consisting of”. 20 The use of “for example”, “etc.”, “or” indicates non-exclusive alternatives without limitation unless otherwise indicated. The use of “include” means “includes, but is not limited to” unless otherwise stated. With reference to Figures 1-4, a preferred embodiment is illustrated. of a gas meter 1. 25 The gas meter 1 comprises a hollow body 10, which defines inside it a compartment of size 11, and a lid 12, which is suitable for closing an opening of access 13 of the hollow body 10. In the example considered, the cover 12 comprises an inlet duct 14 and an outlet duct 15 for the gas. The hollow body 10 and the cover 12 have an elongated shape along one direction 30 of main development N, so that the gas meter 1 has a shape essentially parallelepiped. Inside the measuring compartment 11, a flow conveyor is housed, in the sector identified by the corresponding Anglo-Saxon expression flow conveyor 2 – also referred to as a damper or muffler – according to one embodiment 35 of the present invention, as best seen in Figure 2. The flow conveyor 2 comprises a box-shaped body 21, preferably, of a shape elongated along the main development direction N. Preferably, a terminal portion, corresponding to a first end of the box-shaped body 21, has in plan, a dimension transversal to the main development direction N, greater than the size of a remaining portion of the box body 21. 5 Advantageously, this first (input) end has a larger volume (and is wider), compared to the rest of the box body, to ensure that the flow of incoming gas follows the external geometry of the measuring duct 3 (which has a trumpet-shaped end as best appreciated in Figure 3), with this reducing possible turbulence phenomena. 10 In detail, the box-shaped body 21 comprises two shells 22 and 23 suitable for mate with each other – for example, by means of suitable fastening elements corresponding mechanics. A first shell 22 (upper) comprises an inlet opening 221 and an outlet duct 222. Preferably, the entrance opening 221 is formed in a substantially median position 15 with respect to the length of the box body along the direction of development main. Preferably, the opening includes a grate 223. Advantageously, the grate 223 makes the gas flow entering the flow laminar. conveyor 2, eliminating, or at least reducing, the possibility that the gas flow in the entrance to the measuring duct 3 has a turbulent regime. 20 Otherwise, the outlet duct 222 protrudes substantially in correspondence of a second end of the box-shaped body 21 along the main development direction (opposite to the first). Furthermore, the duct of outlet 222 of box body 21 is suitable for coupling to outlet duct 15 of the hollow body 10. Preferably, the coupling between the outlet ducts 15 and 25 222 forms a fluid path that allows the gas to exit the gas meter 1 only to the fluid passing through the flow conveyor 2. Optionally, the first shell 22 includes spacers 224 suitable for keep the flow conveyor 2 in position, when positioned in cavity 11 with the lid coupled to the hollow body 10. Preferably, the spacers 223 30 protrude from the first shell 21 at the first end of the body box 21. An internal volume of the box-shaped body 21 is divided into a measuring chamber 211 and into an outlet chamber 212 by means of a partition wall 24. Preferably, coupling elements are formed in the internal walls of the 35 shells 22 and 23 in order to ensure a stable coupling between the shells 22 and 23 and the dividing wall 24. Even more preferably, a perimeter seal like this to ensure a hermetic separation of the two chambers 211 and 212. Advantageously, the partition wall 24 comprises an opening 242, preferably, formed in a central region of the dividing wall 24. The opening 242 is surrounded by a neck 243 / 244 which protrudes from both faces of the partition wall and includes fixing means to receive a 5 measuring duct 3 (illustrated in Figure 3), which is housed in the chamber inlet 211, and a diffuser 4, which is housed in the outlet chamber 212. In the example in Figure 3, the measuring duct 3 has a tubular shape substantially cylindrical with an entrance opening 31 in communication with fluid with the inlet chamber 211 of the box body 21 and an outlet opening 10 32 coupled, preferably in a watertight manner, to a neck portion 243 which protrudes from wall 24 towards inlet chamber 211. Preferably, The inlet opening 31 has a flared cross-section. The measuring duct 3 comprises a sensor 5. Preferably, the sensor 5 is of the thermomassive type, known in itself and not described here for brevity. 15 The hollow body 10 comprises an electronic processing unit (not shown), which is housed inside a special casing 16 (illustrated in Figure 1) coupled to an external surface of the hollow body 10. The processing unit electronics is suitable for carrying out remote reading and remote management of the meter gas 1. Furthermore, the casing 16 encloses a battery (not shown) connected 20 to the electronic processing unit in order to provide the necessary electrical energy to the operation of the electronic processing unit. The processing unit electronics is connected to sensor 5 to receive measurement signals generated by the sensor 5 and, if necessary, to supply electrical power to sensor 5. For for example, the electronic processing unit is connected to the sensor 5 by means of 25 an appropriate wiring (not illustrated) and one or more connectors suitable to ensure the watertightness of the cavity 11. Alternatively, the processing unit and the sensor 5 are equipped with wireless communication systems such as radio frequency transmitters / transceivers. Preferably, the flow conveyor 2 houses a support assembly 6 for the 30 measuring duct 3. In the example considered, the support assembly 6 includes a support 61 shaped to keep it in one position operational the measuring duct 3, when coupled to the neck 243. In particular, the operating position requires that the measuring duct 3 and the opening 242 of the partition wall 24 are substantially coaxial. Furthermore, the support assembly 35 6 includes a pair of fixing elements 62, suitable for securing the duct measuring 3 at support 61. In addition, in the exemplary embodiment considered, the flow conveyor 2 comprises a protruding base 25 which protrudes from a rear wall of the second shell 23 towards the inside of the entrance chamber 211. The protruding base 25 is suitable for – for example, shaped so as to – receive the support 61 of the support assembly 6 (as best seen in Figures 2 and 4). 5 With particular reference to Figures 5A-5C, the fluid dynamic element or diffuser 4 has an asymmetric tubular shape, with a tubular body 41 that delimits an entrance opening 42 of substantially circular shape coupled to the neck 242 and an exit opening 43 with a lobed, or oval, shape. Preferably, the inlet opening of the diffuser 4 is coupled to the portion 10 of neck 244 which protrudes from the wall 24 towards the outlet chamber 212. For for example, the coupling between neck portion 244 and diffuser 4 is performed for by means of corresponding fasteners, formed on both elements. In particular, an area Si of the inlet opening 42 is smaller than an area So of the exit opening 43. For example, the areas Si and So are sized so 15 that their So / Si ratio is between about 1 and about 2.2, preferably between about 1.2 and about 2 (1.2 ≤ So / Si ≤ 2). Preferably, the two inlet openings 42 and outlet openings 43 lie on planes substantially parallel and are spaced apart from each other by a distance between approximately 24 mm and approximately 70 mm, preferably between approximately 29 mm and approximately 64 mm – that is, 20 the diffuser 4 has a width L between approximately 29 mm and approximately 64 mm (29 mm ≤ L ≤ 64 mm). Furthermore, the speaker 4 has an asymmetrical flared structure. In detail, considered a lateral section (illustrated in Figure 5B) along a plane of PP section lying along a main development direction T of the opening 25 of outlet 43 and a diameter of the inlet opening 42, a first portion 411 (upper) of the tubular body 41 is defined by a first radius of curvature R1 between approximately 25 mm and approximately 45 mm, preferably between approximately 30 mm and approximately 40 mm (30 mm ≤ R1 ≤ 40 mm). Otherwise, a second portion 412 (lower) of the tubular body 41 is defined by a second radius of curvature R2 30 between approximately 80 mm and approximately 105 mm, preferably between approximately 86 mm and approximately 100 mm (86 mm ≤ R2 ≤ 100 mm). Preferably, the ratio of the two radii of curvature R1 and R2 (i.e., R1 / R2) is between 0.25 and 0.4 (0.25 ≤ R1 / R2 ≤ 0.4). In the example of Figures 5A – 5C, the first portion 411 of the tubular body 41 delimits an apex 431 (or first lobe) of the exit opening 43 while the second 35 portion 412 of tubular body 41 defines a base 432 (or second lobe) of the exit opening 43, where the base 432 is defined by a radius of curvature greater than the radius of curvature that defines the apex 431. Preferably, the diffuser 4 is coupled to the neck 243 so that the apex 431 is closer to the outlet duct 222 than to the base 432 of the same. Even more preferably, the flow conveyor 2 is shaped so that the outlet opening 43 of the diffuser 4 is at a distance D of approximately 15 5 mm and approximately 60 mm, preferably between approximately 20 mm and approximately 55 mm (20 mm ≤ D ≤ 55 mm) from the walls of the flow conveyor 2 which delimit the exit chamber 212, or at least from the wall of the flow conveyor 2 having a parallel orientation to the outlet opening 43 of the diffuser 4. Diffuser 4 is designed to slow down the flow of gas passing through it, i.e. the 10 velocity vi of the incoming gas flow is greater than the velocity vo of the incoming flow output (vo < vi). The Applicant has determined that reducing the flow rate of gas inside the meter leads to a reduction in the absorption of pressure that characterizes the same meter. In particular, the Applicant has determined that the maximum absorption reduction is achievable 15 imposing a reduction in gas velocity in the gas meter area 1 in which the gas flow exits from the measuring duct 3, to head towards the exit from the gas meter 2, i.e. outlet pipe 15. In gas meter 1 considered, equipped with the flow conveyor 2, this area corresponds to the chamber output 212 of the same. Therefore, the diffuser 4 is positioned in the output chamber 20 212, as described above, in order to reduce the speed of the gas exiting the counter. In use, the gas flow enters the measuring compartment 11 delimited by the hollow body 10 through the inlet duct 14 (which is connected to a line of gas distribution). From the measuring compartment 11 the gas flow flows inside 25 of the inlet chamber 211 of the flow conveyor 2, at least once the compartment of measure 11 is saturated with gas. The gas flow, therefore, passes through the duct of measure 3 (which is the only possible path for the gas flow) allowing a particularly reliable measurement of gas flow. Gas flow passes through the opening 242 of the dividing wall 24 and the diffuser 4 and enters the 30 outlet chamber 212 of the flow conveyor 2. Finally, the gas flow leaves the flow conveyor 2 and gas meter 1 through the series of outlet ducts 222 and 15 of the flow conveyor 2 and the hollow body 10, respectively. In particular, the gas flow velocity is reduced as it passes through diffuser 4 which leads to an overall reduction in pressure absorption 35 due to gas meter 1. It is clear, however, that the above examples should not be interpreted in limiting sense and the invention thus conceived is susceptible to numerous changes and variants. In alternative embodiments the diffuser may have a shape different. For example, instead of a curved tubular body, a body is defined tubular structure composed of a plurality of portions of flat walls adjacent to each other. 5 In general, although not in a limiting manner, the speaker according to this invention defines a fluid conduit with a lateral section increasing from a minimum value corresponding to the input opening to a maximum value corresponding to the exit opening. The gas meter according to the embodiments of the present invention is 10 characterized by a flow rate greater than 10,000 ls / h, i.e. standard liters per hour, unit of measurement used in the sector to indicate the flow rate of a flow of air passing at a temperature of 20 °C and a pressure of 1.01325 10 Pa (1.01325 bar) (conditions which correspond to an air density of 1.2 kg / m ). A flow rate of 10,000 ls / h is therefore equivalent to a flow rate of 10 , 15 determined using a flow of air characterized at a temperature of 20 °C and at a pressure of 1.01325 10 Pa. For example, the meter belongs to the category called “G25” having a maximum flow rate of approximately 40 scm / h. Of course, all the details are replaceable by other technically necessary elements. 20 equivalents. For example, in an alternative embodiment (not shown), the sensor may be of another type, such as an ultrasonic sensor. In general, a suitable sensor is configured to detect one or more parameters (temperature, attenuation of ultrasonic waves, or anything else) by means of which it is possible to calculate a 25 value of the gas flow passing through the meter. In an alternative embodiment of the diffuser 4A – of which Figure 6 is a side sectional view – one or more slats, or separators 44, three are provided in the example considered. The 44 separators are suitable for dividing at least partially the volume delimited by the 4A speaker, thus defining two or more 30 ducts overlapping each other in the direction of fluid flow. As illustrated in the example in Figure 6, a generic separator 44 extends between opposite sides of the inner wall of the tubular body 41 of the diffuser 4A in a direction substantially transverse to the direction of the gas passing through it. Preferably, the separator 44 extends, in the direction of fluid flow, to 35 starting from the outlet opening 43 towards the inlet opening 42, preferably without reaching it in order to allow for robust coupling and simple the 4A diffuser at the neck 243. Furthermore, the separator 44 has a profile in curved lateral section, advantageously, having a radius of curvature between the first and second radii of curvature R1 and R2, of the first and second portion 5 411 and 412, respectively, of the tubular body 41. Preferably, the separators 44 are arranged approximately equidistant along the cross-section of the diffuser. More preferably, the separators 44 are arranged in such a way as to obtain internal ducts characterised by cross-sections of approximately the same. 10 The separators 44 and, in particular, the ducts defined by them with the tubular body 41 allow for a more homogeneous gas flow distribution inside the diffuser 4A, compared to the diffuser 4, with the same external shape and overall dimensions. This more homogeneous distribution is obtained keeping the average value of the flow velocity substantially unchanged 15 of gas exiting diffuser 4A, compared to diffuser 4. The 4A diffuser is particularly suitable in gas meters characterised by values of high maximum flow rate, for example above 10 scm / h. The Applicant has observed that, in such gas meters, making the gas flow more homogeneous inside the diffuser helps to further reduce possible 20 turbulences in the gas flow passing through the area between the exit of the diffuser and the gas meter outlet. In a different embodiment the gas meter 1A is flow-free conveyor, as illustrated in the side section view of Figure 7. In this case the measuring duct 3 is positioned directly inside the 25 measuring compartment 11 of gas meter 1A, without containment structures intermediate. In this embodiment, a duct of measurement 3 is provided equipped with a respective flow sensor 5, and the output 32 of the measuring duct 3 a diffuser 4 is applied, in a similar manner to that described above. Furthermore, a dividing wall, or partition 7 is arranged inside the measuring compartment 11. 30 so as to separate it into an input chamber 111 and an output chamber 112. An opening 71 is formed in the septum and is adapted to mate with the outlet opening. 32 of the measuring duct 3 and to the inlet opening 42 of the diffuser 4, so so as to form a single fluid passage between the inlet chamber 111 and the exit chamber 112. In particular, the measuring duct 3 is positioned in the 35 inlet chamber 111, while the diffuser 4 is positioned in the outlet chamber of the measuring chamber 11. Preferably, measuring duct 3 and diffuser 4 are substantially coaxial with each other and with the opening 71 when coupled with the septum 7. Finally, a support element 8 is arranged inside the measuring compartment 11, in particular, in the inlet chamber in order to maintain the measuring duct in a desired operating position, where the measuring duct and the opening 71 5 of septum 7 are substantially coaxial. The presence of diffuser 4 allows you to obtain the same reduction advantages pressure drops also in the 1A gas meter. In embodiments suitable for measuring very high gas flow rates (not illustrated), the gas meter is equipped with two or more sensors each associated with 10 a respective measuring conduit, in turn, housed in a respective flow conveyor. The flow conveyors are housed inside the measuring compartment of the counter, preferably placed on the back wall of the box body placed side by side. In this case the gas meter is equipped with a collector that connect the flow conveyor outlet ducts to the meter outlet duct 15 of gas. Preferably, each of the flow conveyors has a structure corresponding to that of flow conveyor 2 described above. In particular, at least one of the flow conveyors, preferably all, include a respective speaker corresponding to speaker 4 described above. The result is that the meter contains multiple flow sensors, whose measurements 20 are combined and used to determine the actual flow rate of the meter, through mathematical calculations performed by a processing system internal electronics. In addition, the Applicant has determined that a single flow conveyor with diffuser according to the embodiment of the present invention operates in 25 optimal mode with gas flow rates in the range between 10 scm / h and 50 scm / h (included). In the case of gas meters suitable for operating with higher flow rates, the range of maximum flow rate that can be handled by a single flow conveyor – between 10 scm / h and 50 scm / h – is considered a submultiple of the maximum capacity of the gas meter. 30 Therefore, the number of flow conveyors required corresponds to the ratio between the maximum flow rate of the gas meter and the maximum flow rate range of the individual flow conveyor. For example, considering a gas meter with a flow rate maximum of 160 scm / h, a minimum number of flow conveyors to be placed in the measuring space is equal to four considering that four are necessary 35 intervals 10-50 scm / h to obtain the maximum flow rate of 160 scm / h. In this case, each of the four flow conveyors will handle a flow rate of approximately 40 scm / h (160 = 40 x 4). In a gas meter with a maximum flow rate of 100 scm / h, two flow conveyors will be sufficient, each of which will manage a flow of flow rate approximately equal to 50 scm / h. In another embodiment (not illustrated), the gas meter is free of 5 flow conveyor – similar to gas meter 1A – but includes two or more measuring ducts and diffusers. In this case, the septum is equipped with a number corresponding opening, each suitable to receive a respective duct of measure and a respective diffuser coupled to the opening on opposite faces of the septum, as described above. For example, the septal openings are formed in 10 so that the measuring ducts and diffusers are placed next to each other, for for example, with the axes of the ducts lying on the same plane. Advantageously, the gas meter includes a support element, similar to the support element 8, for each measuring duct, or a single support element shaped to support all the ducts 15 measure. In this case, the number of measuring and diffuser ducts will be determined based on the maximum flow rate of the gas meter and a range of maximum flow rates that can be handled by the measuring ducts, in a similar manner to the above described for the embodiment comprising two or more flow conveyors. As will be evident to the technician of the sector, the gas meter according to the forms of 20 embodiment of the present invention is suitable to operate effectively with maximum flow rates of high value, greater than 10 scm / h. In particular, the gas meters according to embodiments of the present invention operate effectively with a maximum flow rate of 160 scm / h – the upper end of the range of possible maximum flow rate values ​​currently required by the 25 gas meter market – or higher, significantly reducing losses of load of the same compared to the known versions without a diffuser. In conclusion, the materials used, as well as the contingent shapes and dimensions of the devices, The above mentioned devices and terminals may be any according to the specific implementation needs without going beyond the scope of 30 protection of the following claims. In particular, the diffuser is preferably made of thermoplastic material of rigid type, produced using a process based on the technique of injection molding. However, the diffuser according to the present invention can be made with another type of material (for example, a 35 suitable metal or a combination of two or more materials - for example, the fluid dynamic element may comprise portions of different materials coupled in a removable or non-removable manner to each other.

Claims

1. A fluid meter (1: 1A) comprising: a box-shaped hollow body (10) which delimits a measuring chamber (11), an inlet conduit (14) and an outlet conduit (15) which allow a flow of fluid into and out of the measuring chamber (11), respectively, a separator assembly (2; 7) included in the measuring chamber which is adapted to define an inlet region (211; 111) adapted to receive the flow of fluid entering the measuring chamber (11) through the inlet conduit (14), and an outlet region (212; 112) adapted to receive the flow of fluid exiting the measuring chamber (11) through the outlet conduit (15), the separator assembly (2; 7) comprising at least one opening (224; 71) adapted to allow a flow of fluid between the inlet region (211; 111) and the outlet region (212; 112). 112), and measuring means (3; 5) arranged inside the entrance region (211;111) in order to provide an indication of a quantity of fluid flowing therethrough, the measuring means comprising at least one measuring conduit (3) coupled to said at least one opening (242; 71) of the separator assembly (2; 7), and wherein the fluid meter (1: 1A) has a maximum flow rate exceeding 10 m3 / h, measured with an air flow with a density of 1.2 kg / m3, characterised in that it comprises a fluid dynamic element (4; 4A) arranged in the outlet region (212; 112), the fluid dynamic element (4; 4A) comprising an inlet opening (42), coupled to the opening (24; 71) of the separator assembly (2; 7), and a free outlet opening (43), wherein the surface of the outlet opening (43) has a substantially oval shape and is larger than the surface of the inlet opening (42), which has a substantially circular shape.; 2. Fluid meter (1; 1A) according to claim 1, wherein a ratio between the surface area of ​​the outlet opening (43) and the inlet opening (42) of the fluid dynamic element (4; 4A) is between about 1 and about 2.2, preferably between about 1.2 and about 2.

3. Fluid meter (1; 1A) according to claim 1 or 2, wherein the surface of the outlet opening (43) and the inlet opening (42) of the fluid dynamic element (4; 4A) lie on substantially parallel planes and are spaced apart from each other by a distance of between about 24 mm and about 70 mm, preferably between about 29 mm and about 64 mm.

4. A fluid meter (1; 1A) according to any of the preceding claims, wherein the fluid dynamic element (4; 4A) has a flared asymmetric structure, and wherein a tubular body (41) of the fluid dynamic element (4; 4A) P1695IT00 comprises a curved portion (411), which has a lateral cross-sectional profile defined by a first radius of curvature of between about 25 mm and about 45 mm, preferably between about 30 mm and about 40 mm, along a main development direction of the outlet opening (43).

5. Fluid meter (1; 1A) according to claim 4, wherein the tubular body (41) comprises a further curved portion (412), which has a lateral cross-sectional profile defined by a further radius of curvature of between about 80 mm and about 105 mm, preferably between about 86 mm and about 100 mm.

6. Fluid meter (1; 1A) according to any of the preceding claims, wherein the fluid dynamic element (4; 4A) comprises a tubular body (11) and at least one separating wall (44) extending inside the tubular body (41), dividing the volume delimited by the tubular body (41) into at least two ducts.

7. Fluid meter (1; 1A) according to claims 6 and 4, wherein the separating wall (44) has a lateral cross-section profile defined by a radius of curvature equal to or less than the first radius of curvature.

8. Fluid meter (1; 1A) according to claim 6 or 7 and claim 5, wherein the separating wall (44) has a lateral cross-sectional profile defined by a radius of curvature equal to or greater than the second radius of curvature.

9. A fluid meter (1) according to any preceding claim, wherein the outlet opening (43) comprises a first lobe (431), defined by a first lobe radius of curvature, and a second lobe (432), defined by a second lobe radius of curvature, wherein the first lobe radius of curvature is less than the second lobe radius of curvature, and wherein the first lobe and the second lobe are at a first distance and a second distance, respectively, from the outlet conduit (15), wherein the first distance is less than the second distance.

10. Fluid meter (1) according to any of the preceding claims, wherein the outlet opening (43) of the fluid dynamic element (4; 4A) faces a wall delimiting the outlet region (212; 112), wherein the outlet opening (43) is at a distance of between about 15 mm and about 60 mm, preferably between about 20 mm and about 55 mm, from said wall delimiting the outlet region (212; 112).

11. Fluid meter (1) according to any of the preceding claims, wherein the separator assembly (2; 7) comprises a box-like body (21) P1695IT00 housed inside the measuring compartment (11), the inlet region (211) and the outlet region (212) being delimited by the box-like body (21) and a wall (24) arranged inside the box-like body, and wherein an inlet opening (221) of the box-like body (21) allows access of the fluid flow from the measuring compartment (11) to the inlet region (211), while a further outlet duct (222) of the separator assembly (2; 7) is coupled to the outlet duct (15) of the gas meter (1, 1A) so that only the fluid inside the outlet region (212) can leave the fluid meter.

12. Fluid meter (1) according to claim 11, comprising a plurality of separator assemblies (2), where the box-shaped body (21) of each separator assembly (2) houses a respective measuring conduit (3) and a respective fluid dynamic element (4).

13. Fluid meter (1A) according to any of the preceding claims, wherein the separator assembly (2; 7) comprises a septum (7) arranged in the measuring compartment (11) and adapted to separate the measuring compartment (11) into the inlet region (111) and the outlet region (112).

14. A fluid meter (1A) according to claim 13, wherein the septum (7) comprises a plurality of openings (71) adapted to allow a flow of fluid between the inlet region (111) and the outlet region (112), wherein a respective measuring conduit (3) and a respective fluid dynamic element (4) are coupled to each opening (71) of the plurality of openings.