Device and method for measuring an air flow rate in an air passage opening

Abstract

The invention relates to a device (1) for measuring an air flow in an opening (B), characterized in that it comprises a sensor (3) for measuring a pressure difference (ΔP), an air flow conditioner (5), an air passage sleeve (6), a box (7) comprising a pressure control device (70) for compensating for the pressure difference (ΔP) at the air inlet port (71), and a computing unit (8) for calculating the air flow rate in the opening (B).

Description

[0001] DESCRIPTION

[0002] Device and method for measuring an air flow in an air passage opening

[0003] The invention relates to a device and a method for measuring an air flow rate passing through an air passage opening.

[0004] The field of the invention relates to air extraction or air supply vents for a building, for example industrial or other. These vents can be arranged in one or more rooms of the building.

[0005] Air supply vents are vents through which air enters a room (usually to be conditioned in temperature and humidity) from an air supply duct to the vent. They generally consist of one or more deflector elements ensuring a reduction in outlet speed and a mixing of the blown air with the air in the room.

[0006] Return (or extraction) vents are generally simple vents, in which the air from a room is sucked into an air suction duct.

[0007] The velocity profiles at the outlet of the vents are generally both vortex and asymmetric.

[0008] 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.

[0009] One field of the invention may be that of nuclear power plants for the production of electricity. In this particular field, the guarantee of reaching and maintaining certain ventilation flow rates is verified during initial tests and during periodic tests, with the aim of verifying the threshold values ​​to be respected depending on the intended applications.

[0010] Known devices and methods for measuring air flow in an air passage opening have numerous disadvantages, mentioned below.

[0011] The method recommended in nuclear power plants, because the measurement uncertainty can be defined based on a standard reference, is measurement by exploring the velocity profiles in the duct. This method requires a certain number of straight lengths of pipes to have a reasonable uncertainty (around 10% of the measurement). In addition, these pipes (or ventilation ducts) are generally positioned at height, leading to possible access difficulties.

[0012] For these reasons (access, implementation constraints), it is common to defer the measurement of flow rates to measurements at the outlets. It is known to implement the measurement at supply or return outlets using anemometer soundings, but this method suffers from high uncertainties regarding the representativeness of the measurement.

[0013] The main difficulties associated with these speed (or flow rate) measurement methods are due to the behavior of the speed profiles and their gradients. The supply or return vents are generally directly integrated into a ventilation network duct (case of vents in non-terminal ducts), inducing asymmetrical speed profiles depending on the main air flow of the network. The outlet or inlet profile in this network is deformed, with a first zone which can induce a depression (and external air sucked in) then a deformed profile in a half-water droplet.These difficulties are due to the fact that the behavior of the outlet velocity profiles can be vortex-like (the shape of the vents generally seeks to promote ventilation by mixing) and / or asymmetrical (when these profiles are integrated into a ventilation network, the outlet or inlet profile in this network is deformed according to the main flow rate of the network: half-drop shape).

[0014] Anemometers are commonly used to measure air speed. There are three main types: vane anemometers, thermal anemometers, and pressure probe anemometers (pitot tubes).

[0015] All these anemometers are sensitive to disturbances encountered at the mouths, as well as to the orientation of the flow.

[0016] A first method generally used to measure air volume flow rates through vents is known, which is that of sampling local speeds, carried out in a plane positioned parallel to the opening, at a given distance. An average speed is then calculated, which will then be corrected by a correction coefficient depending on the type of vent, the immediate environment, the measurement conditions and an equivalent passage surface (to go from a speed in m / s to a volume flow rate in m 3 / hour).

[0017] This first method is by nature not very precise (large variety of exit orifices and environment, irregularity of speed profiles, etc.) and very fragile to the hazards of implementation: the approach speeds having high speed gradients, a bad positioning (in distance or in orientation) immediately induces a bias of great importance.

[0018] A second method is known, that of balometers. The general principle of (direct) flow measurement at outlets is to cover the outlet with a measuring device through which the entire flow passes. The measuring device therefore generally comprises a collector (rigid cone or canvas on a frame in the case of a balometer) positioned on the outlet tested. Since the flow meter and its attachment cone do not allow the velocity profile to be corrected at the level of the integrated measurement (problems similar to a survey) and modify the resistance of the network and therefore the flow passing through the outlet during the 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 drawbacks mentioned above and which allow confidence and a guarantee to be provided on the measurement of the air flow rate.

[0020] For this purpose, a first object of the invention is a device for measuring an air flow rate in an air passage opening in a direction of air passage, characterized in that the measuring device comprises: a first fixing perimeter around the air passage opening, a second perimeter, which is distant from the first perimeter and which has an air passage section, smaller than an air passage section of the first fixing perimeter, a first duct 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 duct 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 duct 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 main direction going from the air inlet cross-section to the air outlet cross-section in the direction of air passage, the air flow conditioner being structured to make the air flow velocity substantially parallel to the main 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 air passage,the air passage sleeve carrying at least one second sensor associated with a first calculator for measuring at least one quantity representative of the air speed in the sleeve, a box, comprising an air inlet access connected downstream of the sleeve in the direction of air passage, an air outlet access and a pressure control device to compensate the pressure difference on the air inlet access, a second calculator for calculating the air flow in the air passage mouth from the at least one quantity representative of the air speed, one of 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 air passage going from the air outlet access to the second perimeter, the air inlet cross section being exposed to the open air, the direction of air passage corresponding to a direction of air extraction from the air inlet cross section towards the first attachment perimeter around the air passage mouth.

[0023] According to one embodiment of the invention, the air inlet cross-section is connected to the second perimeter with the direction of air passage going from the perimeter to the air inlet cross-section, the air outlet access being exposed to the open air, the direction of air passage corresponding to a direction of air blowing from the first attachment perimeter around the air passage mouth 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 spaced from the air inlet cross-section, the air flow conditioner has 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 spaced from the air inlet cross-section, the air flow conditioner has a lattice occupying the intermediate air passage cross-section, the air flow conditioner has 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 air passage cross-section is surrounded by a perimeter substantially equal to that surrounding the air outlet cross-section.

[0026] According to one embodiment of the invention, the cross-section reduction zone is conical.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 main direction in the cuff, the first ultrasonic transducer being able to emit a first ultrasonic wave along the alignment direction towards the second ultrasonic transducer, which is able to receive the first ultrasonic wave in a first transmission-reception mode, 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 computer being configured to calculate the air speed in the cuff from the first travel time.

[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 main direction in the cuff in the air flow direction S, the first ultrasonic transducer being able to emit a first ultrasonic wave along the alignment direction towards the second ultrasonic transducer, which is able to receive the first ultrasonic wave in a first transmission-reception mode, 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 able to emit a second ultrasonic wave along the alignment direction towards the first ultrasonic transducer, which is able to receive the second ultrasonic wave in a second transmission-reception mode, to measure by the first calculator 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 calculator being configured to calculate the speed of the air in the cuff from the first travel time and the second travel time.,

[0028] According to one embodiment of the invention, the second sensor comprises three pairs of first ultrasonic transducer and second ultrasonic transducer, respectively having three alignment directions which are angularly spaced from each other by 120° around the main direction in the cuff.

[0029] According to one embodiment of the invention, the pressure control device comprises at least one fan, which is arranged in the box in a direction of sending air towards the second perimeter, and a regulator for controlling a speed of rotation of the blades of the fan in the direction of sending air towards the second perimeter, the regulator being configured to regulate the speed of rotation of the blades so as to subtract the pressure difference from the air inlet access.

[0030] According to one embodiment of the invention, the regulator comprises a first regulator configured to adjust a rotation speed setpoint as a function of the pressure difference and a second regulator configured to adjust the rotation speed of the fan blades in the direction of sending air towards the second perimeter to the rotation speed setpoint.

[0031] According to one embodiment of the invention, the second perimeter comprises a rigid ring.

[0032] 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 parts 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.

[0033] According to one embodiment of the invention, the rigid rectangular frame comprises airtight seals on a face where it presses against the air passage opening.

[0034] According to one embodiment of the invention, the fixing parts against the air passage opening comprise suction cups or a gripping system by local depression.

[0035] According to one embodiment of the invention, the fixing parts against the air passage opening comprise at least one handle for tightening the rigid rectangular frame against a projecting contour of the air passage opening.

[0036] According to one embodiment of the invention, the rigid rectangular frame comprises: a first length side, comprising first length profiles, which are mounted to slide between them so that the first length side has the adjustable length, and a first member for immobilizing the first length profiles, a second length side, comprising second length profiles, which are mounted to slide between them so that the second length side has the adjustable length, and a second member for immobilizing the second length profiles, a first width side, comprising first width profiles, which are mounted to slide between them so that the first width side has the adjustable width, and a first member for immobilizing the first width profiles, a second width side, comprising second width profiles,which are mounted sliding between them so that the second width side has the adjustable width, and a second member for immobilizing the second width depths.,

[0037] According to one embodiment of the invention, the at least one first sensor for measuring the pressure difference comprises an ambient pressure inlet, located at the same altitude as the air passage opening.

[0038] According to one embodiment of the invention, the device comprises a mobile trolley for transporting the air flow conditioner, the air passage sleeve and the box.

[0039] A second subject of the invention is a method for measuring an air flow rate in an air passage opening in a direction of air flow using the measuring device as described above, the method comprising the following steps: measuring the pressure difference, equal to the second pressure in the at least one second pressure tap, from which the first pressure in the at least one first pressure tap is subtracted, by the at least one first sensor, compensating for the pressure difference on the air inlet access by the pressure control device, measuring at least one quantity representative of the air speed in the sleeve by the first computer from the at least one second sensor, calculating the air flow rate in the air passage opening from the at least one quantity representative of the air speed by the second computer.

[0040] The invention will be better understood upon reading the description which follows, given solely by way of non-limiting example with reference to the figures below of the attached drawings.

[0041] [Fig. 1] represents a schematic view in vertical section of a device for measuring an air flow in an air passage opening according to an embodiment of the invention in air extraction.

[0042] [Fig. 2] represents a schematic view in vertical section of a device for measuring an air flow in an air passage opening according to an embodiment of the invention in air blowing.

[0043] [Fig. 3] represents a schematic perspective view of an air conditioner of the device for measuring an air flow in an air passage opening according to an embodiment of the invention.

[0044] [Fig. 4] 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 an embodiment of the invention. [Fig. 5] 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 an embodiment of the invention.

[0045] [Fig. 6] represents a schematic perspective view of an air passage sleeve of the device for measuring an air flow in an air passage opening according to an embodiment of the invention.

[0046] [Fig. 7] represents a schematic perspective view of an air passage sleeve of the device for measuring an air flow in an air passage opening according to an embodiment of the invention.

[0047] [Fig. 8] represents a schematic view in vertical section of an air passage sleeve of the device for measuring an air flow in an air passage opening according to an embodiment of the invention.

[0048] [Fig. 9] represents a modular block diagram of a pressure control device for a box of the device for measuring an air flow in an air passage opening according to an embodiment of the invention.

[0049] [Fig. 10] represents a schematic view in vertical section of an air conditioner according to the state of the art.

[0050] [Fig. 11] represents a schematic view in vertical section of an air conditioner according to the state of the art.

[0051] [Fig. 12] represents a schematic view in vertical section of an air conditioner of the device for measuring an air flow in an air passage opening according to an embodiment of the invention.

[0052] [Fig. 13] represents a modular block diagram of a sensor control circuit of the device for measuring an air flow in an air passage opening according to one embodiment of the invention.

[0053] [Fig. 14] represents a diagram of a pressure difference created by a fan of the device for measuring an air flow in an air passage opening according to an embodiment of the invention as a function of an air flow.

[0054] [Fig. 15] represents a schematic perspective view of a first conduit of the device for measuring an air flow in an air passage opening according to an embodiment of the invention.

[0055] [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. [Fig. 17] represents a schematic horizontal sectional view of an air passage opening in air extraction, on which the device for measuring an air flow rate and the method for measuring an air flow rate according to an embodiment of the invention can be provided.

[0056] [Fig. 18] represents a schematic horizontal sectional view of an air passage opening in air blowing, on which the device for measuring an air flow rate and the method for measuring an air flow rate according to an embodiment of the invention can be provided.

[0057] [Fig. 19] represents a schematic view in horizontal section of an air passage opening for air extraction or air blowing, on which the device for measuring an air flow rate and the method for measuring an air flow rate according to an embodiment of the invention can be provided.

[0058] An example of a device 1 for measuring a flow rate QB of air passing through an air passage (or ventilation) opening B is described below in more detail with reference to Figures 1 to 19 and with reference to Figure YY an example of a method for measuring the flow rate QB of air in the air passage opening B. The air passage opening B is arranged on an air duct C and communicates with the outside EXT of the air duct C in a direction S of air flow through the air passage opening B. The air passage opening B is arranged in a positioning plane P of the air duct C. The air passage opening B may comprise an opening in which an air passage grille is fixed and which is surrounded by an edge. The air passage opening B has an air passage section SB. The air passage opening B may be bordered by a wall M or a wall M.

[0059] In the example of figures 1, 17 and 19, the air passage mouth B is an air extraction mouth B. The air passage mouth B is provided for the passage of air sent in the direction S of air flow corresponding to the direction SI of air extraction from the exterior EXT of the air duct C to the air duct C through the air passage mouth B. The arrow F corresponds to the direction of air circulation in the air duct C.

[0060] In the example of figures 2, 18 and 19, the air passage mouth B is an air blowing mouth B. The air passage mouth B is provided for the passage of air sent in the direction S of air flow corresponding to the direction S2 of air blowing from the air duct C through the air passage mouth B towards the outside EXT of the air duct C. The arrow F corresponds to the direction of air circulation in the air duct C.

[0061] As shown in Figure 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 state of the art metrologically questionable, and are generally not oriented perpendicular to the plane P of positioning of the vent B, which also weakens the representativeness of the anemometry measurements according to the state of the art, which is sensitive to the direction of the flow.

[0062] As shown in Figure 18, the PV velocity profiles at the outlet of the air blowing outlet B to the outside EXT of the air duct C frequently exhibit irregularities, which makes the use of an average of a survey according to the state of the art metrologically questionable, and are generally not oriented perpendicular to the plane P of positioning of the outlet B, which also weakens the representativeness of the anemometry measurements according to the state of the art, which is sensitive to the direction of the flow.

[0063] The air flow measuring device 1 and the air flow measuring method according to the invention make it possible to address these difficulties in particular.

[0064] In Figures 1 and 2, the device 1 for measuring the air flow rate QB comprises a first part 24 for access to the air passage opening B. The first part 24 for access to the air passage opening B comprises a first fixing perimeter 21, which is intended to be fixed in an airtight manner around the air passage opening B. The first fixing perimeter 21 is connected to a second perimeter 22, which is distant from the first perimeter 21, by a first conduit 2. In the following, all the connections are configured to be airtight.

[0065] The second perimeter 22 has an air passage section S22, smaller than an air passage section S21 of the first attachment perimeter 21. Indeed, there may be different air passage vents B having different air passage sections SB from one another, as shown by way of example in Figure 19. It is provided in one embodiment, which will be described below, that the first attachment perimeter 21 is adjustable to have the adjustable air passage section S21, to allow adaptation to the different air passage vents B having different air passage sections SB from one another. Of course, in other embodiments, the first attachment perimeter 21 could be fixed to have the fixed air passage section S21, to adapt to air passage vents having identical air passage sections SB.Since the air passage mouth B may have a relatively large or variable air passage section SB, it is chosen that the air passage section S22, which is prescribed, is smaller than the air passage section S21 of the first fixing perimeter 21.

[0066] The device 1 for measuring the air flow rate QB comprises one (or more) first sensor 3 for measuring a pressure difference AP along the first duct 2.

[0067] The first measuring sensor 3 may comprise in the first conduit 2 (for example in the skirt 20) one (or more) first pressure taps 320 located between the first attachment perimeter 21 and the second perimeter 22. The first pressure tap(s) 320 may be attached 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 attachment perimeter 21.

[0068] The first measuring sensor 3 may comprise in the first conduit 2 (for example in the skirt 20) one (or more) second pressure taps 330 located between the first pressure tap(s) 320 and the second perimeter 22. The second pressure tap(s) 330 may be fixed to a second ring 33 fixed to the first conduit 2 (for example to the skirt 20). The second pressure tap(s) 330 could also be provided on the second perimeter 22.

[0069] The first sensor(s) 3 measures the pressure difference AP, equal to the second pressure in the second pressure tap(s) 330, from which the first pressure in the first pressure tap(s) 320 is subtracted and may comprise a calculator 34 for this purpose. When several first pressure taps 320 are provided, the first pressure is calculated as the average of the pressures measured at the first pressure taps 320. When several second pressure taps 330 are provided, the second pressure is calculated as the average of the pressures measured at the second pressure taps 330.

[0070] In Figures 1 and 2, the second perimeter 22 is connected to an assembly 10 making it possible to provide 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 measurement sensor 3. The assembly 10 comprises an air flow conditioner 5, an air passage sleeve 6 and a box 7.

[0071] In Figures 1 to 5, the air flow conditioner 5 has an air inlet cross section 51, an air outlet cross section 52 and a main direction 50 extending from the air inlet cross section 51 to the air outlet cross section 52 in the air passage direction S. The air flow conditioner 5 is structured to make the air flow speed 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.

[0072] The air flow conditioner 5 makes it possible to render in the air outlet cross-section 52 the profile of the air speeds V, centered and axialized along the main direction 50 in the direction S of the air flow, and this whatever the shape of the profile of the speeds V in the air inlet cross-section 51. The air flow conditioner 5 makes it possible to have channeled speed profiles V in the air inlet cross-section 51. The air flow conditioner 5 is structured to straighten and redistribute the velocity profile V from the air inlet cross-section 51 to the air outlet cross-section 52 in the air flow direction S, as shown by way of example in Figure 12. As shown by way of example in Figure 10, the straightening consists of channeling the air flow lines V so that they are parallel to the single main direction 50 in the air flow direction S.

[0073] As shown as an example in Figure 11, redistribution consists of obtaining a distribution of the speeds V of the profile as close as possible to that of a profile completely established in the direction S of the air flow.

[0074] As shown by way of example in Figure 12, the straightening and redistribution of the profile of the speeds V from the air inlet cross-section 51 to the air outlet cross-section 52, provided by the air flow conditioner 5, makes it possible to make the air flow speed V substantially parallel to the main direction 50 and with a speed value V having homogeneity to within 50%, as described above in the air flow direction S. The homogeneity of the air speed value in the air outlet cross-section 52 can be taken relative to an air speed value taken at the middle of the air outlet cross-section 52, which can be a maximum air speed relative to the other locations of this air outlet cross-section 52.

[0075] In Figures 1, 2, 6, 7 and 8, the air passage sleeve 6 is delimited internally 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 air passage direction S. The air passage sleeve 6 carries one (or more) second sensors 61a, 61b associated with a first computer 64, which make it possible to measure one (or more) quantities representative of the speed of the air in the sleeve 6. The inner surface 60 may be cylindrical, for example cylindrical and circular, around the main direction 50.

[0076] In Figures 1, 2 and 9, the box 7 comprises an air inlet access 71 connected downstream of the sleeve 6 in the direction S of air passage. The box 7 comprises an air outlet access 72 and a pressure control device 70 to compensate for the pressure difference AP on the air inlet access 71.

[0077] In Figures 1 and 2, the device 1 comprises a second calculator 8 for calculating the air flow rate QB in the air passage opening B from the quantity(ies) representative of the air speed.

[0078] In Figures 1 and 2, one of the air outlet port 72 and the air inlet cross section 51 is connected to the second perimeter 22.

[0079] The invention thus makes it possible to measure the flow rate QB of air passing through the vent B (in air blowing and air extraction) with low uncertainty (< 5% of the flow rate measurement), regardless of the conditions of the air flow in the direction S through the vent B. The invention thus makes it possible to measure relatively high flow rates QB of air passing through the vent B.

[0080] In the embodiment of Figure 1, called air extraction, the air outlet access 72 is connected to the second perimeter 22 with the direction S, S1 of air passage going from the air outlet access 72 to the second perimeter 22. The air inlet cross section 51 being exposed to the open air. The direction S of air passage corresponds to the direction S1 of air extraction from the air inlet cross section 51 to the first perimeter 21 of attachment around the air passage mouth 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 sheath.

[0081] In the embodiment of Figure 2, called air blowing, the air inlet cross section 51 is connected to the second perimeter 22 with the direction S, S2 of air passage going from the perimeter 22 to the air inlet cross section 51. The air outlet access 72 is exposed to the open air. The direction S of air passage corresponds to the direction S2 of air blowing from the first perimeter 21 of attachment around the air passage mouth B towards 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 sheath.

[0082] Embodiments of the air flow conditioner 5 are described below with reference to FIGS. 3-5.

[0083] According to an 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 spaced from the air inlet cross-section 51.

[0084] The air flow conditioner 5 has 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 spaced from the air inlet cross-section 51. The cross-sectional reduction zone 53 may be conical.

[0085] The air flow conditioner 5 comprises a lattice 55 occupying the intermediate air passage cross section 54. The lattice 55 makes it possible to press and flatten the profile of the speeds V onto the intermediate air passage cross section 54. The lattice 55 may be a wire mesh or a stretched mesh. The air flow conditioner 5 comprises a profile 56 delimiting channels 57. The profile 56 and the channels 57 are arranged in a honeycomb pattern and extend parallel to the main direction 50, 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 perpendicular plane parallel to the main direction 50. The channels 57 may have cross-sections different from each other or identical to each other.The profile 56 delimiting channels 57 makes it possible to make the profile of the speeds V parallel to the main direction 50 of the air outlet cross-section 52 and in the direction S of the air flow.

[0086] The air flow conditioner 5 may have a cylindrical, for example cylindrical and circular, outer wall 58 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.

[0087] 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 "." (period) while the sign "," (comma) denotes the fixed point representation of the numbers.

[0088] 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 spaced from the first ultrasonic transducer 61a in an alignment direction 61c having a positive and non-zero projection along the main direction 50 in the sleeve 6 in the air flow direction S. Thus, the alignment direction 61c from the first ultrasonic transducer 61a to the second ultrasonic transducer 61b is inclined by an angle α different from 90° (modulo 180°) with respect to the main direction 50 in the sleeve 6. The angle α is greater than 0° and less than 90°.

[0089] The first ultrasonic transducer 61a (point A in Figure 8) may be located on the inner surface 60 of the cuff 6 and the second ultrasonic transducer 61b (point B in Figure 8) may be located on the inner surface 60 of the cuff 6. In this case, the angle a may be defined by the following equation: where L is the distance between the first ultrasonic transducer 61a and the second ultrasonic transducer 61b along the alignment direction 61c,

[0090] D is the projection of the distance L along the principal direction 50 onto a plane orthogonal to the principal direction 50.

[0091] In the case where the inner surface 60 is cylindrical and circular around the central main direction 50 and where the alignment direction 61c passes through the central main direction 50, the projection D is equal to the inner diameter of the inner surface 60.

[0092] 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 by the first computer 64 to be in the first transmission mode to emit a first ultrasonic wave (for example pulsed) along the alignment direction 61c towards the second ultrasonic transducer 61b. The second ultrasonic transducer 61b can be controlled by a control input 610b by the first computer 64 to be in the first reception mode to 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 speed V of the air in the cuff 6 from the first travel time TAB.

[0093] For a uniform speed V parallel to the main direction 50, equal to the maximum speed Vo of the air taken on the central main direction 50, this speed Vo of the air in the sleeve 6 can be calculated by the first computer 64 in the first transmission-reception mode according to the following equation:

[0094] 1

[0095] Vo = - cosa 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.

[0096] Indeed, the first ultrasonic wave going from point A to point B is accelerated by the speed V in the direction S of air flow, because the speed V of the air has a positive speed component projected onto the path of the first ultrasonic wave along the alignment direction 61c. According to one embodiment, the first computer 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 may be sinusoidal in the envelope of a pulse.

[0097] 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 control input 610b by the first computer 64 to be in the second transmission mode to emit a second ultrasonic wave (for example pulsed) along the alignment direction 61c towards the first ultrasonic transducer 61a. The first ultrasonic transducer 61a can be controlled by the control input 610a by the first computer 64 to be in the second reception mode to 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.

[0098] For a uniform speed V parallel to the main direction 50, equal to the maximum speed Vo of the air taken on the central main direction 50, this speed Vo of the air in the sleeve 6 can be calculated by the first computer 64 in the second transmission-reception mode according to the following equation:

[0099] 1

[0100] Vo = - cosa

[0101] Indeed, the second ultrasonic wave going from point B to point A is slowed down by the speed V in the direction S of air flow, because the speed V of the air has a negative speed component projected onto the path of the second ultrasonic wave along the alignment direction 61c.

[0102] According to one embodiment, the first calculator 64 is configured to measure the second travel time TBA, 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 may be sinusoidal in the envelope of a pulse.

[0103] In a third embodiment, the first ultrasonic transducer 61a and the second ultrasonic transducer 61b may have the second transmission-reception mode after the first transmission-reception mode. In this case, the first computer 64 is configured to calculate the air speed in the sleeve 6 from the first travel time TAB and from the second travel time TBA as representative quantities. For a uniform speed V parallel to the main direction 50, equal to the maximum speed Vo of the air taken on the central main direction 50, this speed Vo of the air in the sleeve 6 may be calculated by the first computer 64 in the second transmission-reception mode according to the following equation:

[0104] 1

[0105] V o = -

[0106] 2. thing

[0107] For a flow having a velocity profile V parallel to the main direction 50 and non-uniform as in Figure 12 in the air outlet cross-section 52 and in the cylindrical and circular sleeve 6 around the central main direction 50, the average velocity V of the air in the sleeve 6 can be calculated by the first computer 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:

[0108] 2 ■ n 2

[0109] V = - VA

[0110] (n + 1) ■ (2 ■ n + 1) 0 with

[0111] 1

[0112] - = 0.25 — 0.023 ■ log Re n where Re is the Reynolds number in the air of the cuff 6 and is a value prescribed and / or pre-recorded in a memory of the first computer 64. This average speed V of the air thus makes it possible to calibrate the measuring device as a function of the speed Vo recorded, to take into account the non-homogeneity of the speed values ​​parallel to the main central direction 50.

[0113] 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 computer 64.

[0114] The first calculator can retain as speed V the calculated speed Vo or the calculated average speed V.

[0115] According to one embodiment, shown as an example in Figures 1, 2, 6 and 7, the second sensor comprises a pair of first ultrasonic transducer 61a and second ultrasonic transducer 61b having the alignment direction 61c respectively, another pair of first ultrasonic transducer 62a and second ultrasonic transducer 62b having the alignment direction 62c respectively and another pair of first ultrasonic transducer 63a and second ultrasonic transducer 63b having the alignment direction 63c respectively. The transducers 61a, 61b, 62a, 62b, 63a, 63b are distinct from each other. The three alignment directions 61c, 62c, 63c are angularly spaced from each other by 120° around the central main direction 50 in the sleeve 6.

[0116] According to one embodiment, shown in Figure 13, the transducers 61a, 61b, 62a, 62b, 63a, 63b are connected to a multiplexer 65 (multiplexer of type 1 to 6 in the example shown) in the transmission mode and are connected to a demultiplexer 66 (demultiplexer 66 of type 1 to 6 in the example shown) in the reception mode. The first computer 64 controls the multiplexer 65 in the transmission mode and the demultiplexer 66 in the reception mode, so that the pair of the aforementioned transducers 61a, 61b is successively in the first transmission-reception mode then in the second transmission-reception mode, the other transducers 62a, 62b, 63a, 63b being switched off.Then, the first computer 64 restarts the control process on another pair of the aforementioned transducers: for example, the first computer 64 controls the multiplexer 65 in the transmission mode and the demultiplexer 66 in the reception mode, so that the pair of the aforementioned transducers 62a, 62b is successively in the first transmission-reception mode then in the second transmission-reception mode, the other transducers 61a, 61b, 63a, 63b being switched off. Then, the first computer 64 restarts the control process on another pair of the aforementioned transducers: for example, the first computer 64 controls the multiplexer 65 in the transmission mode and the demultiplexer 66 in the reception mode, so that the pair of the aforementioned transducers 63a, 63b is successively in the first transmission-reception mode then in the second transmission-reception mode, the other transducers 61a, 61b, 62a, 62b being switched off.The first calculator 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.

[0117] In the various cases above, the second calculator 8 can calculate the air flow rate QB in the air passage mouth B from the quantity(ies) representative of the air speed, for example by multiplying the value of the air passage cross-section 61d of the air passage sleeve 6 by the speed V having been calculated. This air passage cross-section 61d of the air passage sleeve 6 is taken perpendicular to the main direction 50 and is delimited by the inner surface 60.

[0118] Embodiments of the box 7 and the pressure control device 70 are described below with reference to FIGS. 1, 2, 9 and 14.

[0119] The pressure control device 70 comprises a fan 74 arranged in the box 7 between the air inlet access 71 and the air outlet access 72. The fan 74 comprises blades 743 fixed on a rotation axis 745 and is configured to send air into the box 7 in a ventilation direction 741 directed towards the second perimeter 22, when its blades 743 are rotated in a rotation direction determined by the rotation axis 745. The fan 74 comprises a motor 746, which is connected to the rotation axis 745 of the blades 743 and which is controlled at an actual rotation speed N of the blades 743 present on a speed control input 747 of the motor 746. Of course, several fans 74 could be provided in the box 7.

[0120] The pressure control device 70 comprises a regulator 75 for controlling the speed N of rotation of the blades 743 of the fan 74 in the direction 741 of sending air towards the second perimeter 22. The regulator 75 is configured to regulate the speed N of rotation of the blades 743 so as to subtract the pressure difference AP from the air inlet port 71. This makes it possible to remove the effect of the pressure difference AP on the speed measurement carried out in the sleeve 6. Thus, the regulator 75 is configured so that the rotation of the blades 743 of the fan 74 in the determined direction of rotation sends air in the direction 741 of sending air and adds another pressure difference D, equal to the opposite of the pressure difference AP, to the air inlet port 71, i.e. D = -AP.

[0121] Figure 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 sending air on the ordinate as a function of a flow rate Q of passing air (expressed in m 3 .s -1) in 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 other) of the speed N of rotation of the blades 743 of the fan 74 in the direction 741 of air delivery. As illustrated in Figure 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, that is to say Di < D2 < D3.Furthermore, for each speed N of rotation of the blades 743 of the fan 74 in the direction 741 of air delivery, 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 another decreasing (and therefore injective) function fi of the flow rate Q of air passing through the fan 74 in this direction 741 of air delivery, these other decreasing functions fi being different for different speeds N of rotation.

[0122] Thus, in the blowing embodiment of Figure 2, the second air passage section S22 smaller than the first air passage section S21 of the first perimeter 21 causes a pressure loss PC (i.e. the negative pressure difference AP in this case) in the first duct 2, i.e. a pressure reduction in the second air passage section S22 relative to the pressure in the air extraction vent B and in the first air passage section S21 and an increase in the air speed in the second air passage section S22 relative to the air speed in the air extraction vent B and in the first air passage section S21. This negative pressure difference AP may be of the order of -200 Pa for example). The pressure control device 70 compensates for the pressure loss PC on the air inlet access 71 connected to the cuff 6.Thus, the speed measurement is carried out in the sleeve 6 by cancelling the effect of this pressure loss PC, which makes it possible to measure the actual speed of the air in the mouth B. According to the embodiment described above having the fan 74, in order to carry out this compensation D of the pressure loss PC, the fan 74 therefore adds an increase D in pressure (and therefore a decrease in the air speed) in the direction of the air inlet access 71 and therefore sends air in the direction 741 of sending air directed from the air outlet access 72 towards the air inlet access 71, against the direction S of passage of the air, 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 adjusts the speed N of rotation of the blades 743 on the speed control input 747 of the fan 74 so that the sending of air, created by the rotation of the blades 743 in the direction 741 of sending air directed from the air outlet access 72 towards the air inlet access 71, against the direction S of passage of the air, and therefore towards the second perimeter 22, subtracts the pressure difference AP from the air inlet access 71.

[0123] Thus, in the extraction embodiment of Figure 1, the second air passage section S22 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), i.e. an increase in pressure in the second air passage section S22 relative to the pressure in the air extraction vent B and in the first air passage section S21 and a decrease in the air speed in the second air passage section S22 relative to the air speed in the air extraction vent B and in the first air passage section S21. This positive pressure difference AP may be of 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 speed measurement is carried out in the sleeve 6 by cancelling the effect of this overpressure SP, which makes it possible to measure the actual speed of the air in the mouth B. According to the embodiment described above having the fan 74, in order to carry out this compensation D of the overpressure SP, the fan 74 therefore adds a reduction in pressure (and therefore an increase in air speed) in the direction of the air inlet access 71 and therefore sends air in the direction 741 of sending air directed from the air inlet access 71 to the air outlet access 72, in the direction S of passage of the air, 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 adjusts the speed N of rotation of the blades 743 on the speed control input 747 of the fan 74 so that the air delivery, created by the rotation of the blades 743 in the direction 741 of air delivery directed from the air inlet access 71 towards 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.

[0124] According to one embodiment of the invention, the regulator 75 comprises a first regulator 744 configured to adjust a setpoint N CO ns of rotation speed as a function of the pressure difference AP.

[0125] According to one embodiment of the invention, the regulator 75 comprises a first subtractor 748 comprising a first subtractor input 7481, to which the value of the pressure difference AP supplied by the first measuring sensor 3 is sent, and a first adding input 7482 to which the prescribed pressure value of 0 Pa is applied, to provide on its output 7483 the pressure compensation value D equal to the opposite of the pressure difference AP, i.e. D = - AP.

[0126] 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 there the pressure compensation value D equal to - AP. The first regulator 744 is configured to provide on its output 7442 a setpoint N COns of rotation speed. Thus, the first regulator 744 transforms according to a first prescribed regulation function the pressure compensation value D equal to - AP on its input 7441 into the rotation speed setpoint on its output 7442. The first regulator 744 can for example be proportional and integral (PI in figure 9) of its output 7442 as a function of its input 7441. Of course, the first regulator 744 could be of 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.

[0127] According to one embodiment of the invention, the regulator 75 comprises a second regulator 742 configured to adjust the speed N of rotation of the blades 743 in the direction 741 of sending air going towards the second perimeter 22 to the setpoint N CO ns of rotation speed.

[0128] The regulator 75 comprises a second subtractor 749 comprising a first subtractor input 7491, to which the setpoint N is sent. CO ns of rotation speed provided by the output 7442 of the first regulator 744, and a second adding input 7492 to which is applied the value of the speed N of rotation of the blades 743 provided by the second regulator 742, to provide on the output 7493 of the second subtractor 749 the difference AV of rotation speed, equal to the value of the speed N of rotation of the blades 743 from which is subtracted the setpoint N CO ns of rotation speed, i.e. AV = N- N COns. The second regulator 742 has an input 7421 connected to the output 7493 of the second subtractor 749 to receive therein the difference AV in rotational speed. The second regulator 742 has a second prescribed decreasing regulation function, to transform the difference AV in rotational speed into the rotational speed N of the blades 743 on the output 7422 of the second regulator 742. Thus, when the difference AV in rotational speed is positive, the second prescribed decreasing regulation function transforms this positive difference AV in rotational speed into a decrease in the rotational speed N of the blades 743. When the difference AV in rotational speed is negative, the second prescribed decreasing regulation function transforms this negative difference AV in rotational speed into an increase in the rotational speed N of the blades 743.The second regulator 742 may, for example, have proportional and integral action of its output 7442 as a function of its input 7421. Of course, the second regulator 742 could have action other than proportional and integral.

[0129] The second subtractor 749 and the second regulator 742 are part of a second pressure regulation loop B2, shown in broken lines in Figure 9. In fact, the pressure compensation D provided by the fan 74 will then influence the measurement of the pressure difference AP which will be measured by the first measurement sensor 3.

[0130] Embodiments of the first attachment perimeter 21 and the second perimeter 22 are described below with reference to FIGS. 1, 2 and 15.

[0131] According to one embodiment of the invention, the second perimeter 22 comprises a rigid ring 220, for example cylindrical and circular.

[0132] 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 mouth B and fixing parts 211 against the air passage mouth 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 foldable material, such as for example fabric or the like. The skirt 20 thus has an adjustable size. The device 1 comprises one (or more) tensioners 23 connecting the first fixing perimeter 21 to the second perimeter 22 outside the skirt 20 to keep the skirt 20 taut.This embodiment makes it possible to adapt the first fixing perimeter 21 to different sizes of the air passage mouth 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 perimeter 22 prescribed and fixed.

[0133] According to one embodiment of the invention, the rigid rectangular frame 210 comprises air-tight seals 212 on a face where it is pressed against the air passage opening B. The seals 212 may be made of foam or other material.

[0134] According to one embodiment of the invention, the parts 211 for fixing against the air passage opening B comprise vacuum devices (with or without vacuum device). For example, the parts 211 for fixing against the air passage opening B comprise suction cups as vacuum devices.

[0135] According to one embodiment of the invention, the parts 211 for fixing against the air passage opening B comprise at least one handle for tightening the rigid rectangular frame 210 against a projecting contour of the air passage opening B.

[0136] 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 to slide between them so that the first side 213 of length has the adjustable length L1, and a first member 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 to slide between them so that the second side 215 of length has the adjustable length L1, and a second member 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 to slide between them so that the first side 214 of width has the adjustable width L2,and a first member 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 to slide between them so that the second side 216 of width has the adjustable width L2, and a second member 216c for immobilizing the second profiles 216a, 216b of width.,

[0137] The first immobilizing member 213c may be formed by a grip for clamping the first length profiles 213a, 213b against each other. The second immobilizing member 215c may be formed by a grip for clamping the second length profiles 215a, 215b against each other. The first immobilizing member 214c may be formed by a grip for clamping the first width profiles 214a, 214b against each other. The second immobilizing member 216c may be formed by a grip for clamping the second width profiles 216a, 216b against each other.

[0138] According to one embodiment of the invention, the first sensor(s) 3 for measuring the pressure difference AP comprises an ambient pressure inlet 31, located at the same altitude as the air passage opening B.

[0139] According to one embodiment of the invention, the device 1 comprises a mobile carriage 9 for transporting the air flow conditioner 5, the air passage sleeve 6 and the box 7.

[0140] According to one embodiment of the invention, the fan 74 may be of the centrifugal type. According to one embodiment of the invention, the sleeve 6 is produced by three-dimensional printing using a three-dimensional printer.

[0141] The invention also relates to a method for measuring the air flow rate QB in the air passage opening B in the air passage direction S using the measuring device 1 described above. This method is described below with reference to Figure 16. The method comprises the following steps.

[0142] During a first step E1, the pressure difference AP is measured, equal to the second pressure in the second pressure tap(s) 330, from which the first pressure in the first pressure tap(s) 320 is subtracted, by the first sensor(s) 3.

[0143] During a second step E2 after the first step E1, the pressure difference AP on the air inlet access 71 is compensated by the pressure control device 70.

[0144] During a third step E3 subsequent to the second step E2, the quantity(ies) representative of the air speed (for example TAB, and / or TBA) in the sleeve 6 is measured by the first computer 64 from the second sensor(s) 61a, 61b and / or 62a, 62b and / or 63a, 63b.

[0145] During a fourth step E4 subsequent to the third step E3, the air flow rate QB in the air passage opening B is calculated from the quantity(ies) (for example TAB, and / or TBA) representative of the air speed by the second calculator 8.

[0146] The computer 8 and / or the computer 64 and / or the computer 34 may each be implemented by a separate computer or be grouped into a single computer. The computer 8 and / or the computer 64 and / or the computer 34 may be or comprise one (or more) computer(s), one (or more) processor(s), one (or more) microprocessor(s), one (or more) control circuit(s) or others. The computer 8 and / or the computer 64 and / or the computer 34 may have been programmed by a computer program, comprising code instructions for implementing the method, when it is implemented on the computer 8 and / or the computer 64 and / or the computer 34.

[0147] Of course, the field of the invention may only be that of nuclear power plants for producing electricity.

[0148] Of course, the embodiments, features, possibilities and examples described above can be combined with each other or selected independently of each other.

Claims

CLAIMS 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 attachment 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 section (S22), smaller than an air passage section (S21) of the first attachment perimeter (21), a first conduit (2) connecting the first attachment perimeter (21) to the second perimeter (22), at least one first measurement sensor (3), comprising at least one first pressure tap (320), which is located in the first conduit (2) between the first attachment perimeter (21) and the second perimeter (22) or on the first attachment perimeter (21), and at least one second pressure tap (330),which is located in the first duct (2) between the 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), from which is subtracted a first pressure in the at least one first pressure tap (320), an air flow conditioner (5), having an air inlet cross-section (51), an air outlet cross-section (52) and a main direction (50) going from the air inlet cross-section (51) to the air outlet cross-section (52) in the direction (S) of passage of the air, the air flow conditioner (5) being structured to make the air flow speed substantially parallel to the main direction (50) and homogeneous to within 50% in the air outlet cross-section (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 one 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 speed of the air in the sleeve (6), a box (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) for compensating the pressure difference (AP) on the air inlet access (71), a second calculator (8) for calculating the flow rate (QB) of air in the mouth (B) of air passage from at least one quantity (TAB, TBA) representative of the air speed,one of the air outlet access (72) and the air inlet cross section (51) being connected to the second perimeter (22)., . Device according to claim 1, characterized in that one of the air outlet access (72) and the air inlet cross section (51) being 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 passage going from the air outlet access (72) to the second perimeter (22), the air inlet cross section (51) being exposed to the open air, the direction (S) of air passage corresponding to a direction (SI) of air extraction from the air inlet cross section (51) towards the first perimeter (21) of attachment around the air passage mouth (B).

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

5. 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 spaced from the air inlet cross-section (51), the air flow conditioner (5) has a cross-section reduction zone (53) extending from the air inlet cross-section (51) to an intermediate air passage cross-section (54), 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 spaced from the air inlet cross-section (51), the air flow conditioner (5) has a lattice (55) occupying the intermediate cross-section (54) air passage,the air flow conditioner (5) comprises 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)., 6. Device according to claim 5, characterized in that the intermediate air passage cross section (54) is surrounded by a perimeter substantially equal to that surrounding the air outlet cross section (52).

7. Device according to claim 5 or 6, characterized in that the cross-section reduction zone (53) is conical.

8. 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 main direction (50) in the sleeve (6), 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 transmission-reception 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 first calculator (64) being configured to calculate the speed of the air in the sleeve (6) from the first travel time (TAB)., 9. Device according to 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 air flow direction S, 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 transmission-reception 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 able to receive the second ultrasonic wave in a second transmission-reception 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), respectively having three directions (61c, 62c, 63c) of alignment which are angularly spaced from each other by 120° around the main direction (50) in the cuff (6).

11. 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 arranged 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 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 adjust a setpoint (N CO ns) of rotation speed as a function of the pressure difference (AP) and a second regulator (742) configured to adjust to the setpoint (N COns) rotation speed the speed (N) of rotation of the blades (743) of the fan (74) in the direction (741) of sending air towards the second perimeter (22).

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

14. 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 parts (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. Device according to claim 14, characterized in that the rigid rectangular frame (210) comprises air-tight seals (212) on a face where it presses against the air passage opening (B).

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

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

18. 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 between them so that the first side (213) of length has the adjustable length (L1), and a first member (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 to slide between them so that the second side (215) of length has the adjustable length (L1), and a second member (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 slidably mounted between them so that the first side (214) of width has the adjustable width (L2),and a first member (214c) for immobilizing the first width profiles (214a, 214b), a second width side (216), comprising second width profiles (216a, 216b), which are mounted to slide between them so that the second width side (216) has the adjustable width (L2), and a second member (216c) for immobilizing the second width profiles (216a, 216b)., 19. Device according to any one of the preceding claims, characterized in that the at least one first sensor (3) for measuring the pressure difference (AP) comprises 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 carriage (9) for transporting the air flow conditioner (5), the air passage sleeve (6) and the box (7).

21. Method for measuring an air flow rate (QB) in an air passage opening (B) in a direction (S) of air passage using the measuring device (1) according to any one of the preceding claims, the method comprising the following steps: measurement (El) of the pressure difference (AP), equal to the second pressure in the at least one second pressure tap (330), from which the first pressure in the at least one first pressure tap (320) is subtracted, by the at least one 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 speed in the sleeve (6) by the first computer (64) from the at least one second sensor (61a, 61b), calculation (E4) of the air flow rate (QB) in the air passage opening (B) from at least one quantity (TAB, TBA) representative of the air speed by the second calculator (8).

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