Device and method for measuring airflow in an air passage opening

Abstract

The invention relates to a device (1) for measuring airflow in a vent (B), characterized in that it comprises a sensor (3) for measuring a pressure difference (ΔP), an airflow conditioner (5), an air passage sleeve (6), a housing (7) comprising a pressure control device (70) for compensating the pressure difference (ΔP) at the air inlet access (71), and a calculator (8) for calculating the airflow in the vent (B). Figure 1

Description

Title of the invention: Device and method for measuring airflow in an air passage opening

[0001] The invention relates to a device and a method for measuring the flow rate of air passing through an air passage opening.

[0002] The field of the invention relates to air extraction or air supply vents in a building, for example industrial or other. These vents can be located in one or more rooms of the building.

[0003] Air supply vents are vents through which air enters a room (generally one to be temperature and humidity controlled) from an air supply duct to the vent. They are generally made up of one or more deflector elements that reduce the velocity at the outlet and mix the supplied air with the room air.

[0004] Return (or extraction) vents are generally simple vents, in which air from a room is drawn towards an air extraction duct.

[0005] The velocity profiles at the outlet of the mouths are generally both vortex and asymmetric.

[0006] The invention aims to improve the methods implemented for flow measurement seeking to sample or evaluate these speeds and to improve the metrological performance of the methods and devices used.

[0007] One area of ​​the invention may be that of nuclear power plants for electricity production. In this particular area, the guarantee of achieving and maintaining certain ventilation flow rates is verified during initial tests and during periodic tests, in order to verify the threshold values ​​to be respected according to the applications intended.

[0008] The known devices and methods for measuring airflow in an air passage opening have many disadvantages, mentioned below.

[0009] The method recommended in nuclear power plants, because the measurement uncertainty can be defined using a normative reference, is measurement by exploring velocity profiles in ducts. This method requires a certain number of straight lengths of ducts to obtain a reasonable uncertainty (around 10% of the measurement). Furthermore, these ducts (or ventilation ducts) are generally positioned at height, potentially leading to access difficulties.

[0010] For these reasons (access, implementation constraints), it is common to postpone the measurement of flow rates to measurements at the level of the outlets.

[0011] It is known to implement the measurement in supply or return air vents at using anemometer soundings, but this method suffers from high uncertainties regarding the representativeness of the measurement.

[0012] The main difficulties associated with these velocity (or flow rate) measurement methods stem from the behavior of velocity profiles and their gradients. Supply or return air diffusers are generally directly integrated into a duct of the ventilation network (as is the case with diffusers in non-terminal ducts), resulting in asymmetrical velocity profiles depending on the main airflow of the network. The outlet or inlet profile in this network is distorted, with an initial zone that can induce a negative pressure (and external air is drawn in), followed by a distorted profile resembling a half-droplet.These difficulties are due to the fact that the behavior of the exit velocity profiles can be vortex-like (the shape of the outlets generally seeks to promote ventilation by mixing) and / or asymmetrical (when these profiles are integrated into a ventilation network, the exit or inlet profile in this network is deformed according to the main flow of the network: half-droplet shape).

[0013] To measure air velocity, anemometers are generally used. There are usually three types: propeller anemometers, thermal anemometers and pressure probe anemometers (Pitot tubes).

[0014] All these anemometers are sensitive to disturbances encountered at the outlets, as well as to the direction of the flow.

[0015] A first method generally used to measure volumetric airflow rates through vents is known, which is that of local velocity sampling, carried out in a plane positioned parallel to the opening, at a given distance. An average velocity is then calculated, which is subsequently corrected by a correction coefficient depending on the type of vent, the immediate environment, the measurement conditions and an equivalent passage area (to convert from a velocity in m / s to a volumetric flow rate in m³ / hour).

[0016] This first method is by nature, not very precise (large variety of exit orifices and environment, irregularity of velocity profiles ...) and very fragile to the vagaries of implementation: the approach velocities having high velocity gradients, a bad positioning (in distance or in orientation) immediately induces a bias of great importance.

[0017] A second method is known, that of balometers. The general principle of (direct) flow measurement at outlets is to place a measuring device over the outlet, through which the entire flow passes. The measuring device therefore generally comprises a collector (rigid cone or fabric on a frame in the case of a balometer) positioned over the outlet being tested.

[0018] The flow meter and its mounting cone do not allow for correction of the velocity profile at the integrated measurement level (problems similar to those encountered in soundings) and by modifying the resistance of the network and therefore the flow passing through the mouth during measurement (compared to normal operation), the measuring cones / balometers are affected by a measurement bias.

[0019] An objective of the invention is to obtain a device for measuring an air flow rate in an air passage opening, as well as a method for carrying out this measurement, which overcome the disadvantages mentioned above and which allow for confidence and a guarantee on the measurement of the air flow rate.

[0020] To this end, a first object of the invention is a device for measuring airflow in an air passage opening in a direction of airflow, characterized in that the measuring device comprises: an initial fixing perimeter around the air passage opening, a second perimeter, which is further from the first perimeter and which has an air passage cross-section smaller than the air passage cross-section of the first fixing perimeter, a first conduit connecting the first fixing perimeter to the second perimeter, at least one first measuring sensor, comprising at least one first pressure tap, which is located in the first conduit between the first fixing perimeter and the second perimeter or on the first fixing perimeter, and at least one second pressure tap, which is located in the first conduit between the at least one first pressure tap and the second perimeter or on the second perimeter, the at least one first measuring sensor being capable of providing a pressure difference, equal to a second pressure in the at least one second pressure tap, from which is subtracted a first pressure in the at least one first pressure tap, an air flow conditioner, having an air inlet cross-section, an air outlet cross-section and a principal direction from the air inlet cross-section to the air outlet cross-section in the direction of airflow, the air flow conditioner being structured to make the airflow velocity substantially parallel to the principal direction and homogeneous to within 50% in the air outlet cross-section, an air passage sleeve, which is parallel to the main direction, which is connected downstream of the air outlet cross-section in the direction of airflow, the air passage sleeve carrying at least a second sensor associated with a first measuring computer for at least one quantity representative of the air velocity in the sleeve, a casing, comprising an air inlet connected downstream of the sleeve in the direction of airflow, an air outlet, and a pressure control device to compensate for the pressure difference at the air inlet. a second calculator for calculating the airflow in the air passage opening from at least one quantity representative of the air velocity, one of which is the air outlet access and the air inlet cross-section being connected to the second perimeter.

[0021] According to one embodiment of the invention, one of the air outlet access and the air inlet cross section being connected to the second perimeter via a second air duct.

[0022] According to one embodiment of the invention, the air outlet access is connected to the second perimeter with the direction of airflow going from the air outlet access to the second perimeter, with the cross-section of the air inlet open to the atmosphere, the direction of airflow corresponding to an air extraction direction from the cross-section of the air inlet towards the first fixing perimeter around the air passage opening.

[0023] According to one embodiment of the invention, the cross-section of the air inlet is connected to the second perimeter with the direction of air flow from the perimeter to the cross-section of the air inlet, the air outlet access being open to the air, the direction of air flow corresponding to a direction of air blowing from the first perimeter of fixing around the air passage opening towards the air outlet access.

[0024] According to one embodiment of the invention, the air outlet cross-section is smaller than the air inlet cross-section, is parallel to the air inlet cross-section, is opposite the air inlet cross-section and is at a distance from the air inlet cross-section, the airflow conditioner comprises a cross-section reduction zone extending from the air inlet cross-section to an intermediate air passage cross-section, which is smaller than the air inlet cross-section, which is parallel to the air inlet cross-section and which is opposite and at a distance from the air inlet cross-section, The airflow conditioner includes a mesh occupying the intermediate cross-section of the air passage. The airflow conditioner includes a channel profile, which are arranged in a honeycomb pattern and extend parallel to the main direction between the intermediate air passage cross-section and the air outlet cross-section.

[0025] According to one embodiment of the invention, the intermediate cross-section of air passage is surrounded by a perimeter substantially equal to that surrounding the cross-section of air outlet.

[0026] According to one embodiment of the invention, the cross-section reduction zone is conical.

[0027] According to one embodiment of the invention, the second sensor comprises at least one pair of a first ultrasonic transducer and a second ultrasonic transducer, the second ultrasonic transducer being distant from the first ultrasonic transducer in an alignment direction having a non-zero component along the principal direction in the cuff, the first ultrasonic transducer being capable of emitting a first ultrasonic wave along the alignment direction towards the second ultrasonic transducer, which is capable of receiving the first ultrasonic wave in a first emission-reception mode, in order to measure by the first computer as a representative quantity a first travel time of the first ultrasonic wave from the first ultrasonic transducer to the second ultrasonic transducer, the first calculator being configured to calculate the air velocity in the cuff from the first travel time.

[0028] According to one embodiment of the invention, the second sensor comprises at least one pair of a first ultrasonic transducer and a second ultrasonic transducer, the second ultrasonic transducer being distant from the first ultrasonic transducer in an alignment direction having a non-zero component along the principal direction in the cuff in the S direction of airflow, the first ultrasonic transducer being capable of emitting a first ultrasonic wave along the alignment direction towards the second ultrasonic transducer, which is capable of receiving the first ultrasonic wave in a first transmission-reception mode, in order to measure by the first computer as a representative quantity a first travel time of the first ultrasonic wave from the first ultrasonic transducer to the second ultrasonic transducer,the second ultrasonic transducer being capable of emitting a second ultrasonic wave along the alignment direction towards the first ultrasonic transducer, which is capable of receiving the second ultrasonic wave in a second transmit-receive mode, to measure by the first computer as a representative quantity a second travel time of the second ultrasonic wave from the second ultrasonic transducer to the first ultrasonic transducer, the first computer being configured to calculate the air velocity in the cuff from the first travel time and the second travel time.

[0029] According to one embodiment of the invention, the second sensor comprises three pairs of first ultrasonic transducers and second ultrasonic transducers, having respectively three alignment directions which are angularly spaced from each other by 120° around the main direction in the cuff.

[0030] According to one embodiment of the invention, the pressure control device comprises at least one fan, which is disposed in the box in a direction of sending air towards the second perimeter, and a regulator for controlling the rotation speed of the fan blades in the direction of sending air towards the second perimeter, the regulator being configured to regulate the rotation speed of the blades so as to subtract the pressure difference on the air inlet access.

[0031] According to one embodiment of the invention, the regulator comprises a first regulator configured to set a rotation speed setpoint as a function of the pressure difference and a second regulator configured to set the rotation speed of the fan blades in the direction of sending air towards the second perimeter to the rotation speed setpoint.

[0032] According to one embodiment of the invention, the second perimeter comprises a rigid ring.

[0033] According to one embodiment of the invention, the first fixing perimeter comprises a rigid rectangular frame, having an adjustable length and an adjustable width around the air passage opening and fixing pieces against the air passage opening, which are connected to the rigid rectangular frame, the first duct comprises a skirt connecting the first fixing perimeter to the second perimeter, the device comprising at least one tensioner connecting the first fixing perimeter to the second perimeter outside the skirt to keep the skirt taut.

[0034] According to one embodiment of the invention, the rigid rectangular frame includes airtight seals on one face of the frame against the air passage opening.

[0035] According to one embodiment of the invention, the fixing parts against the air passage opening comprise suction cups or a gripping system by local vacuuming.

[0036] According to one embodiment of the invention, the fixing parts against the air passage opening comprise at least one clamping handle for the rigid rectangular frame against a protruding contour of the air passage opening.

[0037] According to one embodiment of the invention, the rigid rectangular frame comprises: a first side of length, comprising first length profiles, which are mounted to slide against each other so that the first side of length has an adjustable length, and a first locking device for the first length profiles, a second side of length, comprising second length profiles, which are mounted sliding between them so that the second side of length has an adjustable length, and a second locking device for the second length profiles, a first width side, comprising first width profiles, which are mounted to slide against each other so that the first width side has an adjustable width, and a first device for fixing the first width profiles, a second width side, comprising second width profiles, which are mounted sliding between each other so that the second width side has an adjustable width, and a second locking device for the second width profiles.

[0038] According to one embodiment of the invention, at least a first pressure difference measurement sensor includes an ambient pressure inlet, located at the same altitude as the air passage opening.

[0039] According to one embodiment of the invention, the device includes a mobile trolley for transporting the air flow conditioner, the air passage sleeve and the box.

[0040] A second object of the invention is a method for measuring the airflow in an air passage opening in a direction of airflow using the measuring device as described above, the method comprising the following steps: measurement of the pressure difference, equal to the second pressure in at least one second pressure tap, minus the first pressure in at least one first pressure tap, by at least one first sensor, compensation for the pressure difference at the air inlet access by the pressure control device, measurement of at least one quantity representative of the air velocity in the cuff by the first computer from at least one second sensor, calculation of the air flow in the air passage opening from at least one quantity representative of the air velocity by the second computer.

[0041] The invention will be better understood upon reading the following description, given solely by way of non-limiting example with reference to the figures below of the attached drawings.

[0042] [Fig-1] represents a schematic vertical cross-sectional view of a measuring device of an air flow rate in an air passage opening according to an embodiment of the invention in air extraction.

[0043] [Fig.2] represents a schematic vertical cross-sectional view of an air flow measurement device in an air passage opening according to an embodiment of the invention in air blowing.

[0044] [Fig. 3] represents a schematic perspective view of an air conditioner of the device for measuring an air flow rate in an air passage opening according to a mode of the realization of the invention.

[0045] [Fig.4] represents a schematic perspective view of an air conditioner of the device for measuring air flow in an air passage opening according to an embodiment of the invention.

[0046] [Fig. 5] represents a schematic perspective view of an air conditioner of the device for measuring air flow in an air passage opening according to an embodiment of the invention.

[0047] [Fig.6] represents a schematic perspective view of a passing sleeve air of the device for measuring an air flow in an air passage opening according to an embodiment of the invention.

[0048] [Fig.7] represents a schematic perspective view of a passing sleeve air of the device for measuring an air flow in an air passage opening according to an embodiment of the invention.

[0049] [Fig.8] represents a schematic vertical cross-sectional view of a cuff of air passage of the air flow measurement device in an air passage opening according to an embodiment of the invention.

[0050] [Fig.9] represents a modular block diagram of a servo control device in pressure of a chamber of the device for measuring an air flow in an air passage opening according to an embodiment of the invention.

[0051] [Fig. 10] represents a schematic vertical cross-sectional view of an air conditioner according to the state of the art.

[0052] [Fig. 11] represents a schematic vertical cross-sectional view of an air conditioner according to the state of the art.

[0053] [Fig. 12] represents a schematic vertical cross-sectional view of an air conditioner of the device for measuring air flow in an air passage opening according to an embodiment of the invention.

[0054] [Fig. 13] represents a modular block diagram of a sensor control circuit of the device for measuring air flow in an air passage opening according to an embodiment of the invention.

[0055] [Fig. 14] represents a diagram of a pressure difference created by a vent user of the device for measuring an air flow rate in an air passage opening according to an embodiment of the invention as a function of an air flow rate.

[0056] [Fig. 15] represents a schematic perspective view of a first conduit of the device for measuring air flow in an air passage opening according to an embodiment of the invention.

[0057] [Fig. 16] represents a flowchart of a method for measuring an air flow rate in an air passage opening according to an embodiment of the invention.

[0058] [Fig. 17] represents a schematic horizontal cross-sectional view of an opening of air passage in air extraction, on which can be provided the device for measuring an air flow rate and the method for measuring an air flow rate according to an embodiment of the invention.

[0059] [Fig. 18] represents a schematic horizontal cross-sectional view of an air passage opening in air blowing, on which the air flow measurement device and the air flow measurement method can be provided according to an embodiment of the invention.

[0060] [Fig. 19] represents a schematic horizontal cross-sectional view of an air passage opening in air extraction or air supply, on which the air flow measurement device and the air flow measurement method can be provided according to an embodiment of the invention.

[0061] An example of a device 1 for measuring the flow rate QB of air passing through an air passage (or ventilation) vent B is described in more detail below with reference to Figures 1 to 19, and an example of a method for measuring the flow rate Qb of air in the air passage B is described with reference to Figure YY. The air passage B is located on an air duct C and communicates with the outside EXT of the air duct C in a direction S of airflow through the air passage B. The air passage B is located in a plane P for positioning the air duct C. The air passage B may have an opening in which an air passage grille is fixed and which is surrounded by a rim. The air passage B has an air passage cross-section SB. The air passage B may be bordered by a wall M or a partition M.

[0062] In the example of Figures 1, 17, and 19, the air passage B is an air extraction vent. The air passage B is designed for the passage of air supplied in the direction S of airflow corresponding to the direction SI of air extraction from the outside EXT of the air duct C to the air duct C through the air passage B. The arrow F corresponds to the direction of airflow in the air duct C.

[0063] In the example of Figures 2, 18, and 19, the air passage B is an air supply vent. The air passage B is designed for the passage of air supplied in the direction S of airflow, corresponding to the direction S2 of air supply from the air duct C, through the air passage B to the outside EXT of the air duct C. The arrow F corresponds to the direction of airflow in the air duct C.

[0064] As shown in [Fig. 17], the PV velocity profiles at the inlet of the air extraction vent B in the air duct C frequently exhibit irregularities, which makes the use of an average of a sounding according to the prior art metrologically questionable, and are generally not oriented perpendicularly to the P positioning plane of the mouth B, which also weakens the representativeness of the measurements by anemometry according to the state of the art, which is sensitive to the direction of the flow.

[0065] As shown in [Fig. 18], the PV velocity profiles at the outlet of the air blower mouth B outside the air duct C frequently exhibit irregularities, which makes the use of an average of a sounding according to the prior art metrologically questionable, and are generally not oriented perpendicular to the plane P of positioning of the mouth B, which also weakens the representativeness of the measurements by anemometry according to the prior art, which is sensitive to the direction of flow.

[0066] The air flow measurement device 1 and the air flow measurement method according to the invention make it possible to deal with these difficulties in particular.

[0067] In Figures 1 and 2, the air flow measurement device 1 QB comprises a first access portion 24 to the air passage opening B. This first access portion 24 to the air passage opening B includes a first mounting perimeter 21, which is intended to be fixed airtight around the air passage opening B. The first mounting perimeter 21 is connected to a second perimeter 22, which is located away from the first perimeter 21, by a first conduit 2. In the following, all connections are configured to be airtight.

[0068] The second perimeter 22 has an air passage cross-section S22 that is smaller than the air passage cross-section S21 of the first fixing perimeter 21. This is because there may be different air passage openings B with different air passage cross-sections SB, as illustrated by way of example in [Fig. 19]. In one embodiment, which will be described below, the first fixing perimeter 21 is adjustable so that the air passage cross-section S21 is also adjustable, allowing it to adapt to different air passage openings B with different air passage cross-sections SB. Of course, in other embodiments, the first fixing perimeter 21 could be fixed so that the air passage cross-section S21 is fixed, allowing it to adapt to air passage openings with identical air passage cross-sections SB.Since the air passage opening B can have a relatively large or variable air passage cross-section SB, it is chosen that the prescribed air passage cross-section S22 is smaller than the air passage cross-section S21 of the first fixing perimeter 21.

[0069] The device 1 for measuring the air flow rate QB includes one (or more) first sensor 3 for measuring a pressure difference AP along the first conduit 2.

[0070] The first measuring sensor 3 may include in the first conduit 2 (for example in the skirt 20) one (or more) first pressure tap 320 located between the first mounting perimeter 21 and the second perimeter 22. The first (or the) first The pressure tap 320 can be fixed to a first ring 32 attached to the first conduit 2 (for example, to the skirt 20). The first pressure tap(s) 320 could also be provided on the first perimeter 21 of attachment.

[0071] The first measuring sensor 3 may include in the first conduit 2 (for example in the skirt 20) one (or more) second pressure port(s) 330 located between the first pressure port(s) 320 and the second perimeter 22. The second pressure port(s) 330 may be attached to a second ring 33 fixed to the first conduit 2 (for example to the skirt 20). The second pressure port(s) 330 could also be provided on the second perimeter 22.

[0072] The first sensor(s) 3 measures the pressure difference AP, equal to the second pressure in the second pressure port(s) 330, minus the first pressure in the first pressure port(s) 320, and may include a calculator 34 for this purpose. When several first pressure ports 320 are provided, the first pressure is calculated as the average of the pressures measured at the first pressure ports 320. When several second pressure ports 330 are provided, the second pressure is calculated as the average of the pressures measured at the second pressure ports 330.

[0073] In Figures 1 and 2, the second perimeter 22 is connected to an assembly 10 that provides a measurement of the air flow rate QB in the air passage opening B, taking into account the pressure difference AP measured by the first measuring sensor 3. The assembly 10 comprises an air flow conditioner 5, an air passage sleeve 6, and a housing 7.

[0074] In Figures 1 to 5, the airflow conditioner 5 has an air inlet cross-section 51, an air outlet cross-section 52, and a main direction 50 from the air inlet cross-section 51 to the air outlet cross-section 52 in the S direction of airflow. The airflow conditioner 5 is structured to make the airflow velocity substantially parallel to the main direction 50 and homogeneous to within 50% in the air outlet cross-section 52, in particular homogeneous to within 30% in the air outlet cross-section 52, and preferably homogeneous to within 20% in the air outlet cross-section 52.

[0075] The airflow conditioner 5 makes it possible to render in the outlet cross-section 52 of air the velocity profile V of the air, centered and axially aligned along the principal direction 50 in the S direction of the airflow, regardless of the shape of the velocity profile V in the inlet cross-section 51 of air. The airflow conditioner 5 makes it possible to have channeled velocity profiles V in the inlet cross-section 51 of air. The airflow conditioner 5 is structured to straighten and redistribute the velocity profile V of the cross-section air inlet 51 to air outlet cross section 52 in the S direction of the airflow, as shown as an example in [Fig. 12].

[0076] As shown by way of example in [Fig.10], the straightening consists of channeling the airflow lines V so that they are parallel to the single main direction 50 in the direction S of the airflow.

[0077] As shown by way of example in [Fig.1 1], the redistribution consists of obtaining a velocity distribution V of the profile as close as possible to that of a profile totally established in the direction S of the airflow.

[0078] As illustrated by way of example in [Fig. 12], the straightening and redistribution of the velocity profile V from the air inlet cross-section 51 to the air outlet cross-section 52, ensured by the airflow conditioner 5, makes the airflow velocity V substantially parallel to the main direction 50 and with a velocity value V having homogeneity to within 50%, as described above in the S direction of airflow. The homogeneity of the air velocity value in the air outlet cross-section 52 can be taken with respect to an air velocity value taken at the midpoint of the air outlet cross-section 52, which may be a maximum air velocity relative to other locations in this air outlet cross-section 52.

[0079] In Figures 1, 2, 6, 7, and 8, the air passage sleeve 6 is internally delimited by an inner surface 60 parallel to the main direction 50. The air passage sleeve 6 is connected downstream of the air outlet cross-section 52 in the S direction of airflow. The air passage sleeve 6 carries one (or more) second sensor 61a, 61b associated with a first computer 64, which allows the measurement of one (or more) quantity representative of the air velocity in the sleeve 6. The inner surface 60 can be cylindrical, for example, cylindrical and circular, around the main direction 50.

[0080] In Figures 1, 2, and 9, the housing 7 includes an air inlet port 71 connected downstream of the sleeve 6 in the S direction of airflow. The housing 7 includes an air outlet port 72 and a pressure control device 70 to compensate for the pressure difference AP at the air inlet port 71.

[0081] In figures 1 and 2, the device 1 includes a second calculator 8 for calculating the air flow rate Qb in the air passage mouth B from the quantity (or quantities) representing the air velocity.

[0082] In Figures 1 and 2, one of the air outlet access 72 and the air inlet cross section 51 is connected to the second perimeter 22.

[0083] The invention thus makes it possible to measure the flow rate QB of air passing through the mouth B (in air supply and air extraction mode) with a low uncertainty (< 5% of the flow rate measurement), regardless of the airflow conditions. in the S direction through the mouth B. The invention thus makes it possible to measure relatively high air flow rates QB, passing through the mouth B.

[0084] In the embodiment of [Fig. 1], referred to as the air extraction embodiment, the air outlet access 72 is connected to the second perimeter 22 with the airflow direction S, SI, from the air outlet access 72 to the second perimeter 22. The air inlet cross-section 51 is open to the atmosphere. The airflow direction S corresponds to the air extraction direction SI from the air inlet cross-section 51 towards the first perimeter 21, which is fixed around the air outlet B. The air outlet access 72 can be connected to the second perimeter 22 via a second air duct 4. The second air duct 4 can be a flexible duct.

[0085] In the embodiment of [Fig. 2], referred to as the air supply embodiment, the air inlet cross-section 51 is connected to the second perimeter 22 with the airflow direction S, S2, from the perimeter 22 to the air inlet cross-section 51. The air outlet access 72 is open to the atmosphere. The airflow direction S corresponds to the air supply direction S2 from the first perimeter 21, which is fixed around the air outlet B, to the air outlet access 72. The air inlet cross-section 51 can be connected to the second perimeter 22 via a second air duct 4. The second air duct 4 can be a flexible duct.

[0086] Embodiments of the air flow conditioner 5 are described below with reference to Figures 3 to 5.

[0087] According to one embodiment of the invention, shown by way of example in Figures 3 to 5, the air outlet cross-section 52 is smaller than the air inlet cross-section 51. The air outlet cross-section 52 is parallel to the air inlet cross-section 51. The air outlet cross-section 52 is opposite the air inlet cross-section 51 and is at a distance from the air inlet cross-section 51.

[0088] The airflow conditioner 5 includes a cross-sectional reduction zone 53 extending from the air inlet cross-section 51 to an intermediate air passage cross-section 54. The intermediate air passage cross-section 54 is therefore smaller than the air inlet cross-section 51. The intermediate air passage cross-section 54 is parallel to the air inlet cross-section 51 and is opposite and at a distance from the air inlet cross-section 51. The cross-sectional reduction zone 53 may be conical.

[0089] The airflow conditioner 5 includes a mesh 55 occupying the intermediate cross-section 54 of the air passage. The mesh 55 allows the velocity profile V to be flattened and smoothed over the intermediate cross-section 54 of the air passage. The mesh 55 may be a wire mesh or a tensioned mesh.

[0090] The airflow conditioner 5 comprises a profile 56 delimiting channels

[0091]

[0092]

[0093]

[0094]

[0095]

[0096] 57. The profile 56 and the channels 57 are arranged in a honeycomb pattern and extend parallel to the main direction 50, either between the intermediate air passage cross-section 54 and the air outlet cross-section 52 or from the intermediate air passage cross-section 54 to the air outlet cross-section 52. The channels 57 may have a hexagonal cross-section in a plane perpendicular to and parallel with the main direction 50. The channels 57 may have different or identical cross-sections. The profile 56, which defines the channels 57, makes the velocity profile V parallel to the main direction 50 of the air outlet cross-section 52 and in the S direction of the airflow. The airflow conditioner 5 may have a cylindrical outer wall 58, for example cylindrical and circular, around the main direction 50, from the intermediate air passage cross-section 54 to the air outlet cross-section 52. The intermediate air passage cross-section 54 may be surrounded by a perimeter substantially equal to that surrounding the air outlet cross-section 52. Embodiments of the air passage sleeve 6 are described below with reference to figures 1, 2, 6, 7 and 8. In the equations below, multiplication is denoted by the sign “.” (dot) while the sign “,” (comma) denotes the fixed-point representation of numbers. The second sensor comprises one (or more) pairs of a first ultrasonic transducer 61a and a second ultrasonic transducer 61b. The second ultrasonic transducer 61b is offset from the first ultrasonic transducer 61a in an alignment direction 61c having a positive, non-zero projection along the principal direction 50 in the sleeve 6 in the S direction of airflow. Thus, the alignment direction 61c from the first ultrasonic transducer 61a to the second ultrasonic transducer 61b is inclined at an angle α other than 90° (modulo 180°) with respect to the principal direction 50 in the sleeve 6. The angle α is greater than 0° and less than 90°. The first ultrasonic transducer 61a (point A in [Fig.8]) can be located on the inner surface 60 of the cuff 6 and the second ultrasonic transducer 61b (point B in [Fig.8]) can be located on the inner surface 60 of the cuff 6. In this case, the angle a can be defined by the following equation: cosa- > / l-(B ) 2 where L is the distance between the first ultrasonic transducer 61a and the second ultrasonic transducer 61b along the alignment direction 61c, D is the projection of the distance L along the principal direction 50 onto an or- plane thogonal to the main direction 50.

[0097] In the case where the inner surface 60 is cylindrical and circular around the central principal direction 50 and where the alignment direction 61c passes through the central principal direction 50, the projection D is equal to the inner diameter of the inner surface 60.

[0098] In a first embodiment, a first transmission-reception mode of the first ultrasonic transducer 61a (point A in [Fig. 8]) and the second ultrasonic transducer 61b (point B in [Fig. 8]) is described below. The first ultrasonic transducer 61a can be controlled by a control input 610a from the first computer 64 to enter the first transmission mode and emit a first ultrasonic wave (for example, a pulse) along the alignment direction 61c towards the second ultrasonic transducer 61b. The second ultrasonic transducer 61b can be controlled by a control input 610b from the first computer 64 to enter the first reception mode and receive the first ultrasonic wave. The first computer 64 detects the first ultrasonic wave received by the second ultrasonic transducer 61b.The first computer 64 measures, as a representative quantity, a first travel time TAb of the first ultrasonic wave from the first ultrasonic transducer 61a to the second ultrasonic transducer 61b. The first computer 64 is configured to calculate the velocity V of the air in the cuff 6 from the first travel time TAb.

[0099] For a uniform velocity V parallel to the main direction 50, equal to the maximum air velocity Vo taken on the central main direction 50, this air velocity Vo in the cuff 6 can be calculated by the first computer 64 in the first transmit-receive mode according to the following equation:

[0100] = v 0 cosa ( T ey

[0101] where L is the distance between the first ultrasonic transducer 61a and the second ultrasonic transducer 61b along the alignment direction 61c, the value c is the speed of sound in air.

[0102] Indeed, the first ultrasonic wave going from point A to point B is accelerated by the velocity V in the direction S of airflow, because the velocity V of the air has a positive velocity component projected onto the path of the first ultrasonic wave along the alignment direction 61c.

[0103] According to one embodiment, the first calculator 64 is configured to measure the first travel time TAB, for example, by correlating the signal received by the second ultrasonic transducer 61b with the first ultrasonic wave emitted by the first ultrasonic transducer 61a. For this purpose, the first ultrasonic wave can to be sinusoidal within the envelope of a pulse.

[0104] In a second embodiment, a second transmission-reception mode of the first ultrasonic transducer 61a (point A in [Fig. 8]) and the second ultrasonic transducer 61b (point B in [Fig. 8]) is described below. The second ultrasonic transducer 61b can be controlled by the first computer 64 via the control input 610b to enter the second transmission mode and emit a second ultrasonic wave (e.g., a pulsed wave) along the alignment direction 61c towards the first ultrasonic transducer 61a. The first ultrasonic transducer 61a can be controlled by the first computer 64 via the control input 610a to enter the second reception mode and receive the second ultrasonic wave. The first computer 64 detects the second ultrasonic wave received by the first ultrasonic transducer 61a.The first computer 64 measures, as a representative quantity, the second travel time TBa of the second ultrasonic wave from the second ultrasonic transducer 61b to the first ultrasonic transducer 61a. The first computer 64 is configured to calculate the air velocity in the cuff 6 from the second travel time TBa.

[0105] For a uniform velocity V parallel to the main direction 50, equal to the maximum velocity Vo of the air taken on the central main direction 50, this velocity Vo of the air in the cuff 6 can be calculated by the first computer 64 in the second transmit-receive mode according to the following equation:

[0106] y - _1_ . (c_ _L_ 1

[0107] Indeed, the second ultrasonic wave going from point B to point A is slowed down by the velocity V in the S direction of airflow, because the velocity V of the air has a negative velocity component projected onto the path of the second ultrasonic wave along the 61c alignment direction.

[0108] According to one embodiment, the first computer 64 is configured to measure the second time TBA of the path, for example by correlating the signal received by the first ultrasonic transducer 61a with the second ultrasonic wave emitted by the second ultrasonic transducer 61b. For this purpose, the second ultrasonic wave can be sinusoidal within the envelope of a pulse.

[0109] In a third embodiment, the first ultrasonic transducer 61a and the second ultrasonic transducer 61b may have the second transmit-receive mode after the first transmit-receive mode. In this case, the first calculator 64 is configured to calculate the air velocity in the cuff 6 from the first time TAB of the journey and from the second time TBA of the journey as representative quantities. For a uniform velocity V parallel to the main direction 50, equal to the maximum air velocity Vo taken in the direction main central 50, this air velocity Vo in the cuff 6 can be calculated by the first computer 64 in the second transmit-receive mode according to the following equation:

[0110] V,-—L-.p___M 0 2£osa \ Tab Tba )

[0111] For a flow having a velocity profile V parallel to the main direction 50 and non-uniform as in Figure 12 in the outlet cross-section 52 of air and in the cylindrical and circular cuff 6 around the central main direction 50, the average velocity V of the air in the cuff 6 can be calculated by the first calculator 64 as a function of the maximum velocity Vo of the air calculated according to one of the embodiments described above according to the following equation:

[0112] V =------V (n+l)(2-n+l)

[0113] with

[0114] 1 = 0.25 - 0.023 • logRe

[0115] where Re is the Reynolds number in the air of the cuff 6 and is a prescribed and / or pre-recorded value in a memory of the first computer 64. This average air velocity V thus allows the measuring device to be calibrated according to the recorded velocity Vo, to take into account the non-homogeneity of velocity values ​​parallel to the central principal direction 50.

[0116] In the above, c and / or L and / or D and / or a and / or cosa and / or n and / or Re may have been prescribed and / or pre-recorded in a memory of the first calculator 64.

[0117] The first computer can retain as speed V the calculated speed Vo or the calculated average speed V.

[0118] According to one embodiment, shown by way of example in Figures 1, 2, 6 and 7, the second sensor comprises a pair of first ultrasonic transducers 61a and second ultrasonic transducers 61b having alignment direction 61c respectively, another pair of first ultrasonic transducers 62a and second ultrasonic transducers 62b having alignment direction 62c respectively, and another pair of first ultrasonic transducers 63a and second ultrasonic transducers 63b having alignment direction 63c respectively. The transducers 61a, 61b, 62a, 62b, 63a, 63b are distinct from one another. The three directions 61c, 62c, 63c alignments are angularly spaced 120° apart from each other around the central principal direction 50 in the cuff 6.

[0119] According to one embodiment, shown in Figure 13, the transducers 61a, 61b, 62a, 62b, 63a, 63b are connected to a multiplexer 65 (a 1-to-6 type multiplexer in the example shown) in the transmit mode and are connected to a demultiplexer 66 (a 1-to-6 type demultiplexer 66 in the example shown) in the output mode. reception. The first computer 64 commands the multiplexer 65 in transmit mode and the demultiplexer 66 in receive mode, so that the pair of the aforementioned transducers 61a, 61b are successively in the first transmit-receive mode and then in the second transmit-receive mode, the other transducers 62a, 62b, 63a, 63b being off. Then, the first computer 64 starts the control process again on another pair of the aforementioned transducers: for example, the first computer 64 commands the multiplexer 65 in transmit mode and the demultiplexer 66 in receive mode, so that the pair of the aforementioned transducers 62a, 62b is successively in the first transmit-receive mode and then in the second transmit-receive mode, the other transducers 61a, 61b, 63a, 63b being off.Then, the first computer 64 repeats the control process on another pair of the aforementioned transducers: for example, the first computer 64 commands the multiplexer 65 in transmit mode and the demultiplexer 66 in receive mode, so that the aforementioned pair of transducers 63a, 63b is successively in the first transmit-receive mode and then in the second transmit-receive mode, the other transducers 61a, 61b, 62a, 62b being switched off. The first computer can retain as speed V an average of the speeds Vo calculated on the different pairs of transducers 61a, 61b, 62a, 62b, 63a, 63b or an average of the average speeds V calculated on the different pairs of transducers 61a, 61b, 62a, 62b, 63a, 63b.

[0120] In the various cases above, the second calculator 8 can calculate the air flow rate QB in the air passage opening B from the quantity (or quantities) representing the air velocity, for example by multiplying the value of the cross-sectional area 61d of the air passage sleeve 6 by the calculated velocity V. This cross-sectional area 61d of the air passage sleeve 6 is taken perpendicular to the main direction 50 and is delimited by the inner surface 60.

[0121] Embodiments of the box 7 and the pressure control device 70 are described below with reference to figures 1, 2, 9 and 14.

[0122] The pressure control device 70 includes a fan 74 disposed in the housing 7 between the air inlet 71 and the air outlet 72. The fan 74 has blades 743 fixed on a rotational axis 745 and is configured to send air into the housing 7 in a ventilation direction 741 directed towards the second perimeter 22, when its blades 743 are rotated in a direction determined by the rotational axis 745. The fan 74 includes a motor 746, which is connected to the rotational axis 745 of the blades 743 and is controlled at an actual speed N of rotation of the blades 743 present on a speed control input 747 of the motor 746. Of course, several fans 74 could be provided in compartment 7.

[0123] The pressure control device 70 includes a regulator 75 for controlling the rotational speed N of the fan blades 743 of the fan 74 in the direction 741 of air delivery towards the second perimeter 22. The regulator 75 is configured to regulate the rotational speed N of the blades 743 so as to subtract the pressure difference AP on the air inlet access 71. This makes it possible to remove the effect of the pressure difference AP on the velocity measurement taken in the cuff 6. Thus, the regulator 75 is configured so that the rotation of the fan blades 743 of the fan 74 in the determined direction of rotation sends air in the direction 741 of air delivery and adds another pressure difference D, equal to the opposite of the pressure difference AP, on the air inlet access 71, i.e. D = -AP.

[0124] Fig. 14 represents on the ordinate the other pressure difference D (expressed in Pa) created by the rotation of the blades 743 of the fan 74 in the direction 741 of air delivery on the ordinate as a function of a flow rate Q of air passing (expressed in m³.s⁻¹) through the fan 74 in this direction 741 of air delivery on the abscissa. The other pressure difference D created by the rotation of the blades 743 of the fan 74 in the direction 741 of air delivery is a first increasing function fi (which may, for example, be quadratic or otherwise) of the speed N of rotation of the blades 743 of the fan 74 in the direction 741 of air delivery. As illustrated in Fig.

[14] , when the speed N of rotation of the blades 743 of the fan 74 in the direction 741 of sending air increases, for example for this speed N successively equal to Ni (for which the other pressure difference D is equal to Di), then N2 (for which the other pressure difference D is equal to D2), then N3 (for which the other pressure difference D is equal to D3) with Ni < N2 < N3, the other pressure difference D created by the rotation of the blades 743 of the fan 74 in the direction 741 of sending air increases, i.e. Di < D2 < D3.Furthermore, for each rotational speed N of the fan blades 743 of the fan 74 in the direction 741 of air delivery, the other pressure difference D created by the rotation of the fan blades 743 of the fan 74 in the direction 741 of air delivery is another decreasing (and therefore injective) function f2 of the air flow rate Q passing through the fan 74 in this direction 741 of air delivery, these other decreasing functions f2 being different for different rotational speeds N.

[0125] Thus, in the blowing embodiment of [Fig. 2], the second air passage section S22, being smaller than the first air passage section S21 of the first perimeter 21, causes a pressure drop PC (i.e., the negative pressure difference AP in this case) in the first duct 2, i.e., a decrease in pressure in the second air passage section S22 compared to the pressure in the air extraction outlet B and in the first air passage section S21, and an increase in the air velocity in the second section S22. Airflow relative to the air velocity in the air extraction vent B and in the first airflow section S21. This negative pressure difference AP can be on the order of -200 Pa, for example. The pressure control device 70 compensates for the pressure drop PC at the air inlet 71 connected to the sleeve 6. Thus, the velocity measurement is performed in the sleeve 6 by canceling the effect of this pressure drop PC, which allows the actual air velocity in vent B to be measured.According to the embodiment described above, with fan 74, in order to compensate D for the pressure drop PC, the fan 74 adds a pressure increase D (and therefore a decrease in air velocity) towards the air inlet 71. It thus directs air in the direction 741, from the air outlet 72 to the air inlet 71, against the direction S of airflow, by rotating its blades 743 in the predetermined direction of rotation. The fan 74 subtracts the pressure difference AP from the air inlet 71.The regulator 75 sets the rotational speed N of the blades 743 on the fan speed control input 747 so that the air supply, created by the rotation of the blades 743 in the direction 741 of air supply directed from the air outlet access 72 to the air inlet access 71, against the direction S of air passage, and therefore towards the second perimeter 22, subtracts the pressure difference AP on the air inlet access 71.

[0126] Thus, in the extraction embodiment of [Fig. 1], the second air passage section S22, being smaller than the first air passage section S21 of the first perimeter 21, causes an overpressure SP in the first duct 2 (i.e., the positive pressure difference AP in this case), that is, an increase in pressure in the second air passage section S22 compared to the pressure in the air extraction vent B and in the first air passage section S21, and a decrease in the air velocity in the second air passage section S22 compared to the air velocity in the air extraction vent B and in the first air passage section S21. This positive pressure difference AP can be on the order of +200 Pa, for example. The pressure control device 70 compensates for the overpressure SP on the air inlet access 71 connected to the sleeve 6.Thus, the velocity measurement is performed in the cuff 6 by canceling the effect of this overpressure SP, which allows the actual air velocity in the outlet B to be measured. According to the embodiment described above, having the fan 74, in order to perform this compensation D of the overpressure SP, the fan 74 therefore adds a pressure decrease (and thus an increase in air velocity) in the direction of the air inlet 71 and therefore sends air in the direction 741 of directed air supply from the air inlet 71 to the air outlet 72, in the direction S of air passage, by the rotation of its blades 743 in the determined direction of rotation. The . Fan 74 subtracts the pressure difference AP from the air inlet access 71. The regulator 75 sets the rotational speed N of the blades 743 on the fan speed control input 747 so that the air supply, created by the rotation of the blades 743 in the direction 741 of air supply directed from the air inlet access 71 to the air outlet access 72, in the direction S of air passage and therefore towards the second perimeter 22, subtracts the pressure difference AP from the air inlet access 71.

[0127] According to one embodiment of the invention, the regulator 75 comprises a first regulator 744 configured to set a rotation speed setpoint Ncons as a function of the pressure difference AP.

[0128] According to one embodiment of the invention, the regulator 75 includes a first subtractor 748 having a first subtractor input 7481, to which is sent the value of the pressure difference AP provided by the first measuring sensor 3, and a first adder input 7482 to which is applied the prescribed pressure value of 0 Pa, to provide on its output 7483 the pressure compensation value D equal to the opposite of the pressure difference AP, that is to say D = - AP.

[0129] According to one embodiment of the invention, the regulator 75 comprises a first regulator 744 having an input 7441 connected to the output 7483 to receive the pressure compensation value D equal to -AP. The first regulator 744 is configured to provide a rotational speed setpoint Ncons on its output 7442. Thus, the first regulator 744 transforms, according to a first prescribed control function, the pressure compensation value D equal to -AP on its input 7441 into the rotational speed setpoint Ncons on its output 7442. The first regulator 744 may, for example, have proportional and integral (PI) action of its output 7442 as a function of its input 7441. Of course, the first regulator 744 could have action other than proportional and integral. The first measuring sensor 3, the first subtractor 748 and the first regulator 744 are part of a first pressure regulation loop B1.

[0130] According to one embodiment of the invention, the regulator 75 includes a second regulator 742 configured to adjust the rotation speed N of the blades 743 in the direction 741 of sending air towards the second perimeter 22 to the rotation speed setpoint Ncons.

[0131] The controller 75 includes a second subtractor 749 having a first subtractor input 7491, to which is sent the rotational speed setpoint Ncons provided by the output 7442 of the first controller 744, and a second adder input 7492 to which is applied the value of the rotational speed N of the blades 743 provided by the second controller 742, to provide on the output 7493 of the second subtractor 749 the rotational speed difference AV, equal to the value of the rotational speed N of the blades 743 from which is subtracted the setpoint Ncons of rotational speed, i.e., AV = N - Ncons. The second controller 742 has an input 7421 connected to the output 7493 of the second subtractor 749 to receive the rotational speed difference AV. The second controller 742 has a second decreasing prescribed control function to transform the rotational speed difference AV into the rotational speed N of the blades 743 at the output 7422 of the second controller 742. Thus, when the rotational speed difference AV is positive, the second decreasing prescribed control function transforms this positive rotational speed difference AV into a decrease in the rotational speed N of the blades 743. When the rotational speed difference AV is negative, the second decreasing prescribed control function transforms this negative rotational speed difference AV into an increase in the rotational speed N of the blades 743.The second regulator 742 can, for example, have proportional and integral action on its output 7442 as a function of its input 7421. Of course, the second regulator 742 could have action other than proportional and integral.

[0132] The second subtractor 749 and the second regulator 742 form part of a second pressure regulation loop B2, shown in dashed lines in [Fig. 9]. Indeed, the pressure compensation D provided by the fan 74 will subsequently influence the measurement of the pressure difference AP which will be measured by the first measuring sensor 3.

[0133] Embodiments of the first perimeter 21 of fixation and of the second perimeter 22 are described below with reference to figures 1, 2 and 15.

[0134] According to one embodiment of the invention, the second perimeter 22 comprises a rigid ring 220, for example cylindrical and circular.

[0135] According to one embodiment of the invention, the first fixing perimeter 21 comprises a rigid rectangular frame 210, having an adjustable length L1 and an adjustable width L2 around the air passage opening B, and fixing pieces 211 against the air passage opening B, which are connected to the rigid rectangular frame 210. The first duct 2 comprises a skirt 20 connecting the first fixing perimeter 21 to the second perimeter 22. The skirt 20 is airtight. The skirt 20 may be made of a deformable and / or flexible material, such as fabric or other. The skirt 20 thus has an adjustable size. The device 1 comprises one (or more) tensioner(s) 23 connecting the first fixing perimeter 21 to the second perimeter 22 on the outside of the skirt 20 to keep the skirt 20 taut.This embodiment allows the first fixing perimeter 21 to be adapted to different sizes of the air passage opening B, while keeping the second perimeter 22 prescribed and fixed, the skirt 20 ensuring the transition between the first fixing perimeter 21 which can vary and the second prescribed and fixed perimeter 22.

[0136] According to one embodiment of the invention, the rigid rectangular frame 210 It includes airtight seals 212 on one face of the plate against the air passage opening B. The seals 212 may be made of foam or other material.

[0137] According to one embodiment of the invention, the fixing parts 211 against the air passage opening B comprise vacuum devices (with or without a vacuum device). For example, the fixing parts 211 against the air passage opening B comprise suction cups as vacuum devices.

[0138] According to one embodiment of the invention, the fixing parts 211 against the air passage opening B comprise at least one clamping handle for the rigid rectangular frame 210 against a protruding contour of the air passage opening B.

[0139] According to one embodiment of the invention, the rigid rectangular frame 210 comprises biocable sliding profiles in position. For example, the rigid rectangular frame 210 comprises: a first side 213 of length, comprising first profiles 213a, 213b of length, which are mounted sliding between each other so that the first side 213 of length has the adjustable length L1, and a first device 213c for immobilizing the first profiles 213a, 213b of length, a second side 215 of length, comprising second profiles 215a, 215b of length, which are mounted sliding between each other so that the second side 215 of length has the adjustable length L1, and a second device 215c for immobilizing the second profiles 215a, 215b of length, a first side 214 of width, comprising first profiles 214a, 214b of width, which are mounted sliding between each other so that the first side 214 of width has the adjustable width L2, and a first device 214c for immobilizing the first profiles 214a, 214b of width, a second side 216 of width, comprising second profiles 216a, 216b of width, which are mounted sliding between each other so that the second side 216 of width has the adjustable width L2, and a second device 216c for immobilizing the second profiles 216a, 216b of width.

[0140] The first locking member 213c can be formed by a clamping handle of the first lengthwise profiles 213a, 213b against each other. The second locking member 215c can be formed by a clamping handle of the second lengthwise profiles 215a, 215b against each other. The first locking member 214c can be formed by a clamping handle of the first widthwise profiles 214a, 214b against each other. The second locking member 216c can be formed by a clamping handle of the second widthwise profiles 216a, 216b against each other.

[0141] According to one embodiment of the invention, the first sensor (or sensors) 3 for measuring the pressure difference AP comprises an ambient pressure inlet 31, located at the same altitude as air passage opening B.

[0142] According to one embodiment of the invention, the device 1 comprises a mobile trolley 9 for transporting the air flow conditioner 5, the air passage sleeve 6 and the box 7.

[0143] According to one embodiment of the invention, the fan 74 can be of the centrifugal type.

[0144] According to one embodiment of the invention, the cuff 6 is produced by three-dimensional printing using a three-dimensional printer.

[0145] The invention also relates to a method for measuring the air flow rate QB in the air passage opening B in the direction S of airflow using the measuring device 1 described above. This method is described below with reference to [Fig. 16]. The method comprises the following steps.

[0146] During a first step El, the pressure difference AP is measured, equal to the second pressure in the second pressure socket (or sockets) 330, from which the first pressure in the first pressure socket (or sockets) 320 is subtracted, by the first sensor (or sensors) 3.

[0147] During a second step E2 subsequent to the first step El, the pressure difference AP on the air inlet access 71 is compensated by the pressure control device 70.

[0148] During a third step E3 subsequent to the second step E2, the quantity (or quantities) representing the air velocity (for example TAB, and / or TBA) is measured in the cuff 6 by the first computer 64 from the second sensor (or sensors) 61a, 61b and / or 62a, 62b and / or 63a, 63b.

[0149] During a fourth step E4 subsequent to the third step E3, the air flow rate Qb in the air passage mouth B is calculated from the quantity (or quantities) (for example TAB, and / or TBA) representing the air velocity by the second calculator 8.

[0150] The control unit 8 and / or the control unit 64 and / or the control unit 34 may each be implemented by a separate control unit or may be combined into a single control unit. The control unit 8 and / or the control unit 64 and / or the control unit 34 may be or comprise one or more computers, one or more processors, one or more microprocessors, one or more control circuits, or other components. The control unit 8 and / or the control unit 64 and / or the control unit 34 may have been programmed by a computer program, including code instructions for implementing the method, when implemented on the control unit 8 and / or the control unit 64 and / or the control unit 34.

[0151] Of course, the field of the invention may only be that of nuclear power plants for the production of electricity.

[0152] Of course, the embodiments, features, possibilities and examples described above can be combined with each other or selected independently of each other.

Claims

Demands

1. Device (1) for measuring an air flow rate (QB) in an air passage opening (B) in an air passage direction (S), characterized in that the measuring device (1) comprises: a first mounting perimeter (21) around the air passage opening (B), a second perimeter (22), which is distant from the first perimeter (21) and which has an air passage cross-section (S22) smaller than an air passage cross-section (S21) of the first mounting perimeter (21), a first conduit (2) connecting the first mounting perimeter (21) to the second perimeter (22), at least one first measuring sensor (3), comprising at least one first pressure tap (320), which is located in the first conduit (2) between the first mounting perimeter (21) and the second perimeter (22) or on the first mounting perimeter (21), and at least one second pressure tap (330),which is located in the first conduit (2) between at least one first pressure tap (320) and the second perimeter (22) or on the second perimeter (22), the at least one first measuring sensor (3) being capable of providing a pressure difference (AP) equal to a second pressure in the at least one second pressure tap (330), less a first pressure in the at least one first pressure tap (320), an airflow conditioner (5) having an air inlet cross-section (51), an air outlet cross-section (52), and a principal direction (50) from the air inlet cross-section (51) to the air outlet cross-section (52) in the direction (S) of airflow, the airflow conditioner (5) being structured to render the airflow velocity substantially parallel to the principal direction (50) and homogeneous to within 50% in the cross-section air outlet (52),an air passage sleeve (6), which is parallel to the main direction (50), which is connected downstream of the air outlet cross section (52) in the direction (S) of air passage, the air passage sleeve (6) carrying at least a second sensor (61a, 61b; 62a, 62b; 63a, 63b) associated with a first calculator (64) for measuring at least one quantity (TAB, TBA) representative of the air velocity in the sleeve (6), a casing (7), comprising an air inlet access (71) connected downstream of the sleeve (6) in the direction (S) of air passage, an air outlet access (72) and a pressure control device (70) to compensate on the air inlet access (71) the pressure difference (AP), a second calculator (8) for calculating the air flow rate (QB) in the air passage mouth (B) from at least one quantity (TAB, TBA) representative of the air velocity, one of the air outlet access (72) and the air inlet cross-section (51) being connected to the second perimeter (22).

2. Device according to claim 1, characterized in that one of the air outlet access (72) and the air inlet cross section (51) is connected to the second perimeter (22) via a second air duct (4).

3. Device according to claim 1 or 2, characterized in that the air outlet access (72) is connected to the second perimeter (22) with the direction (S) of air flow from the air outlet access (72) to the second perimeter (22), the cross-section of air inlet (51) being open to the air, the direction (S) of air flow corresponding to a direction (SI) of air extraction from the cross-section of air inlet (51) to the first perimeter (21) of attachment around the air passage mouth (B).

4. Device according to claim 1 or 2, characterized in that the cross-section of air inlet (51) is connected to the second perimeter (22) with the direction (S) of air flow going from the perimeter (22) to the cross-section of air inlet (51), the access (72) of air outlet being open to the air, the direction (S) of air flow corresponding to a direction (S2) of air blowing from the first perimeter (21) of fixing around the mouth (B) of air passage to the access (72) of air outlet.

5. A device according to any one of the preceding claims, characterized in that the air outlet cross-section (52) is smaller than the air inlet cross-section (51), is parallel to the air inlet cross-section (51), is opposite the air inlet cross-section (51), and is at a distance from the air inlet cross-section (51), the airflow conditioner (5) comprising a cross-section reduction zone (53) extending from the air inlet cross-section (51) to an intermediate cross-section (54) of

6.

7.

8.

9. air passage, which is smaller than the air inlet cross section (51), which is parallel to the air inlet cross section (51) and which is opposite and at a distance from the air inlet cross section (51), the air flow conditioner (5) includes a lattice (55) occupying the intermediate air passage cross section (54), the air flow conditioner (5) includes a channel profile (56), which are arranged in a honeycomb pattern and which extend parallel to the main direction (50) between the intermediate air passage cross section (54) and the air outlet cross section (52). Device according to claim 5, characterized in that the intermediate cross-section (54) of air passage is surrounded by a perimeter substantially equal to that surrounding the cross-section of air outlet (52). Device according to claim 5 or 6, characterized in that the cross-section reduction zone (53) is conical. A device according to any one of the preceding claims, characterized in that the second sensor (61a, 61b) comprises at least one pair of a first ultrasonic transducer (61a) and a second ultrasonic transducer (61b), the second ultrasonic transducer (61b) being distant from the first ultrasonic transducer (61a) in an alignment direction (61c) having a non-zero component along the principal direction (50) in the sleeve (6), the first ultrasonic transducer (61a) being capable of emitting a first ultrasonic wave along the alignment direction (61c) towards the second ultrasonic transducer (61b), which is capable of receiving the first ultrasonic wave in a first transmit-receive mode, for measuring by the first computer (64) as a representative quantity a first travel time (TAB) of the first ultrasonic wave from the first ultrasonic transducer (61a) to the second ultrasonic transducer (61b),the first calculator (64) being configured to calculate the air velocity in the cuff (6) from the first time (Tab) of the journey.

9. Device of any one of claims 1 to 7, characterized in that the second sensor (61a, 61b) comprises at least one pair of a first ultrasonic transducer (61a) and a second ultrasonic transducer (61b), the second ultrasonic transducer (61b) being distant from the first ultrasonic transducer (61a) in an alignment direction (61c) having a non-zero component along the main direction (50) in the cuff (6) in the S direction of airflow, the first ultrasonic transducer (61a) being able to emit a first ultrasonic wave along the alignment direction (61c) towards the second ultrasonic transducer (61b), which is able to receive the first ultrasonic wave in a first transmit-receive mode, to measure by the first computer (64) as a representative quantity a first travel time (TAB) of the first ultrasonic wave from the first ultrasonic transducer (61a) to the second ultrasonic transducer (61b), the second ultrasonic transducer (61b) being able to emit a second ultrasonic wave along the alignment direction (61c) towards the first ultrasonic transducer (61a),which is capable of receiving the second ultrasonic wave in a second transmit-receive mode, to measure by the first computer (64) as a representative quantity a second travel time (TBa) of the second ultrasonic wave from the second ultrasonic transducer (61b) to the first ultrasonic transducer (61a), the first computer (64) being configured to calculate the air velocity in the cuff (6) from the first travel time (TAB) and the second travel time (TBA).

10. Device according to claim 8 or 9, characterized in that the second sensor (61a, 61b) comprises three pairs of first ultrasonic transducer (61a, 62a, 63a) and second ultrasonic transducer (61b, 62b, 63b), having respectively three directions (61c, 62c, 63c) of alignment which are angularly spaced from each other by 120° around the principal direction (50) in the cuff (6).

11. A device according to any one of the preceding claims, characterized in that the pressure control device (70) comprises at least one fan (74), which is disposed in the box (7) in a direction (741) of sending air towards the second perimeter (22), and a regulator (75) for controlling a speed (N) of rotation of the fan blades (743) of the fan (74) in the direction (741) of sending air towards the second perimeter (22), the regulator (75) being configured to regulate the speed (N) of rotation of the blades (743) so as to subtract the pressure difference (AP) from the air inlet access (71).

12. Device according to claim 11, characterized in that the regulator (75) comprises a first regulator (744) configured to set a setpoint (Ncons) of rotational speed as a function of the pressure difference (AP) and a second regulator (742) configured to set the rotational speed (N) of the blades (743) of the fan (74) in the direction (741) of sending air towards the second perimeter (22) to the setpoint (Ncons) of rotational speed.

13. Device according to any one of the preceding claims, characterized in that the second perimeter (22) comprises a rigid ring (220).

14. A device according to any one of the preceding claims, characterized in that the first fixing perimeter (21) comprises a rigid rectangular frame (210), having an adjustable length (L1) and an adjustable width (L2) around the air passage opening (B) and fixing pieces (211) against the air passage opening (B), which are connected to the rigid rectangular frame (210), the first duct (2) comprises a skirt (20) connecting the first fixing perimeter (21) to the second perimeter (22), the device (1) comprising at least one tensioner (23) connecting the first fixing perimeter (21) to the second perimeter (22) outside the skirt (20) to keep the skirt (20) taut.

15. A device according to claim 14, characterized in that the rigid rectangular frame (210) has airtight seals (212) on one face of the frame against the passage opening (B).

16. CL d.

11. Device according to claim 14 or 15, characterized in that the fixing parts (211) against the air passage mouth (B) comprise suction cups or a gripping system by local vacuuming.

17. Device according to any one of claims 14 to 16, characterized in that the fixing parts (211) against the air passage mouth (B) comprise at least one clamping handle of the rigid rectangular frame (210) against a salient contour of the air passage mouth (B).

18. A device according to any one of claims 14 to 17, characterized in that the rigid rectangular frame (210) comprises: a first side (213) of length, comprising first profiles (213a, 213b) of length, which are mounted to slide relative to each other to that the first side (213) of length has an adjustable length (L1), and a first device (213c) for securing the first profiles (213a, 213b) of length, a second side (215) of length, comprising second profiles (215a, 215b) of length, which are mounted to slide relative to each other so that the second side (215) of length has an adjustable length (L1), and a second device (215c) for securing the second profiles (215a, 215b) of length, a first side (214) of width, comprising first profiles (214a, 214b) of width, which are mounted to slide relative to each other so that the first side (214) of width has an adjustable width (L2), and a first device (214c) for securing the first profiles (214a, 214b) of width, a second side (216) width, comprising second width profiles (216a, 216b), which are mounted sliding between them so that the second width side (216) has an adjustable width (L2),and a second device (216c) for immobilizing the second profiles (216a, 216b) of width.

19. Device according to any one of the preceding claims, characterized in that at least a first pressure difference (AP) measuring sensor (3) has an ambient pressure inlet (31) located at the same altitude as the air passage opening (B).

20. Device according to any one of the preceding claims, characterized in that the device comprises a mobile trolley (9) for transporting the air flow conditioner (5), the air passage sleeve (6) and the box (7).

21. A method for measuring an air flow rate (QB) in an air passage opening (B) in an airflow direction (S) using the measuring device (1) according to any one of the preceding claims, the method comprising the following steps: measurement (E1) of the pressure difference (AP), equal to the second pressure in at least a second pressure port (330), less the first pressure in at least a first pressure port (320), by at least a first sensor (3); compensation (E2) of the pressure difference (AP) on the air inlet access (71) by the pressure control device (70); measurement (E3) of at least one quantity (Tab, TBa) representative of the air velocity in the cuff (6) by the first computer (64). starting from at least one second sensor (61a, 61b), calculation (E4) of the air flow (QB) in the air passage mouth (B) from at least one quantity (TAB, TBA) representative of the air velocity by the second computer (8).

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