QUALITOMETRY PRECAST FROM A LIQUID METER

Description

[0001] The invention relates to the field of communicating fluid meters. BACKGROUND OF THE INVENTION

[0002] Drinking water distribution is ensured by distribution networks which include pipes and hydraulic devices that optimize the flow of water from water reservoirs to end-user facilities via the pipes.

[0003] For health and safety reasons, it is essential to monitor the quality of drinking water.

[0004] The quality of the distributed water depends, of course, on the quality of the water at the time of its collection, the treatments it undergoes, but also on the materials it comes into contact with in the reservoirs and during its circulation in the distribution network. Deposition phenomena (biofilms, scaling, metal oxides, etc.) can indeed occur in the reservoirs and pipes.

[0005] Water producers, network managers and health authorities therefore monitor the quality of the distributed drinking water very closely and continuously.

[0006] However, this monitoring can lack precision, particularly due to the vastness of the distribution networks. For example, the water quality observed at end-user locations within a specific area may be significantly lower than the quality assessed upstream of that area. This can result from localized degradation of the pipes, which the monitoring systems are unable to detect.

[0007] It therefore seems worthwhile to try to improve the accuracy of water supply quality assessments based on location within the network. Ideally, the cost associated with this improvement should not be too high.

[0008] Document KR 102 406 733 B1 describes a fluid meter based on an ultrasonic measurement of flow rate juxtaposed with a measurement of turbidity. SUBJECT OF THE INVENTION

[0009] The invention relates to a solution enabling, in a fluid distribution network, the improvement of the accuracy of the evaluation of the quality of the fluid supply as a function of location, said solution having a limited cost. SUMMARY OF THE INVENTION

[0010] To achieve this goal, a fluid meter is proposed comprising: a conduit in which the fluid flows; an emitter arranged to emit a light signal into the conduit; a receiver arranged to receive the light signal after it has traveled a predefined path in the conduit; a processing unit arranged to acquire an electrical signal produced by the receiver, and to evaluate the turbidity of the fluid from said electrical signal.

[0011] The emitter and receiver of the light signal are therefore used to assess the turbidity of the fluid flowing in the meter's conduit.

[0012] Turbidity is a relevant parameter for measuring the quality of the fluid supply. Turbidity is assessed by the meter itself, and therefore at the end-user's installation. The invention thus enables a measurement of the fluid supply's quality, which is associated with a very precise location within the network.

[0013] The cost of turbidity assessment is greatly reduced, as the emitter and receiver of the light signal are inexpensive components and simple to integrate into the meter.

[0014] We also propose a fluid meter as previously described, in which the fluid flows in the conduit in a first direction, and in which the predefined path extends in a second direction perpendicular to the first direction.

[0015] We also propose a fluid meter as previously described, in which the light signal is an infrared signal.

[0016] We also propose a fluid meter as previously described, in which the emitter is a light-emitting diode and the receiver is a photodiode.

[0017] We also propose a fluid meter as previously described, in which the conduit includes two holes, and in which the emitter and receiver each extend at least partially through one of the holes.

[0018] We also propose a fluid meter as previously described, in which the two holes are located on the conduit at diametrically opposite positions.

[0019] We also propose a fluid meter as previously described, in which the electrical signal is an electric current, and in which the turbidity evaluated by the processing unit is inversely proportional to said electric current.

[0020] We also propose a fluid meter as previously described, further comprising an ultrasonic measuring device including an upstream transducer and a downstream transducer and arranged to measure a fluid flow rate, the emitter and receiver being positioned downstream of the upstream and downstream transducers.

[0021] We also propose a fluid meter as previously described, the processing unit being arranged to evaluate quality parameters representative of the quality of a fluid supply, said quality parameters including the turbidity of the fluid.

[0022] We also propose a fluid meter as previously described, the quality measurement parameters further including a fluid temperature.

[0023] We also propose a fluid meter as previously described, the processing unit being arranged to evaluate a speed of sound in the fluid using the ultrasonic measuring device, and then to evaluate the temperature of the fluid from the speed of sound.

[0024] We also propose a fluid meter as previously described, in which the meter includes at least one pressure sensor, the quality measurement parameters further including a pressure measured by said pressure sensor.

[0025] We also propose a fluid meter as previously described, in which the meter includes an upstream pressure sensor, positioned on one side of an upstream end of the conduit, and a downstream pressure sensor, positioned on one side of a downstream end of the conduit, the quality measurement parameters further including a pressure value representative of a pressure difference between an upstream pressure measured by the upstream pressure sensor and a downstream pressure measured by the downstream pressure sensor.

[0026] We also propose a fluid meter as previously described, further comprising a communication module, the processing unit being arranged to receive via the communication module a request issued by a system external to the fluid meter, and to, in response to said request, transmit the quality measurement parameters to said system.

[0027] We also propose a measurement method, implemented in the processing unit of a fluid meter as previously described, comprising the following steps: control the transmitter so that it emits the light signal into the conduit; acquire the electrical signal produced by the receiver; evaluate the turbidity of the fluid from said electrical signal.

[0028] We also propose a computer program comprising instructions which lead the fluid meter processing unit as previously described to execute the steps of the measurement process as previously described.

[0029] In addition, a computer-readable recording medium is proposed, on which the computer program as previously described is recorded.

[0030] The invention will be better understood in light of the following description of a particular, non-limiting embodiment of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Reference will be made to the attached drawings, among which: [ Fig. 1 ] there figure 1 represents a water meter; [ Fig. 2 ] there figure 2 represents a simplified and partial cross-sectional view of the meter conduit, along a plane passing through a longitudinal axis of the conduit. DETAILED DESCRIPTION OF THE INVENTION

[0032] With reference to the figure 1 Water meter 1 is used to measure the water consumption of an end user's installation 2. Water is supplied to installation 2 by a water distribution network 3.

[0033] Meter 1 has a conduit 4 through which flows the water supplied by network 3 to installation 2. The water flows in conduit 4 from upstream to downstream, as indicated by the direction of the arrows F. Here, "upstream" means on the side of network 3, and "downstream" means on the side of installation 2.

[0034] Counter 1 includes a processing unit 5 (electronic and software). Processing unit 5 includes at least one processing component 5a, which is, for example, a "general-purpose" processor, a processor specialized in signal processing (or DSP, for Digital Signal Processor), a microcontroller, or a programmable logic circuit such as an FPGA (for Field Programmable Gate Arrays) or an ASIC (for Application Specific Integrated Circuit).

[0035] The processing unit 5 also includes one or more memories 5b, connected to or integrated into the processing component 5a. At least one of these memories 5b forms a computer-readable recording medium, on which is recorded at least one computer program comprising instructions which lead the processing component 5a to execute at least some of the steps of the measurement process which will be described below.

[0036] The processing component 5a is here the metrology microcontroller of counter 1. The microcontroller 5a integrates an analog-to-digital converter (ADC) 6.

[0037] The counter 1 also includes a communication module 7. The communication module 7 implements, for example, a cellular radio link according to the LTE-Cat M1 protocol or the NB-IoT protocol.

[0038] Meter 1 also includes an ultrasonic measuring device 8. The ultrasonic measuring device 8 is used to measure the water flow supplied to installation 2 by network 3.

[0039] The ultrasonic measuring device 8 includes an upstream transducer 9a and a downstream transducer 9b. The ultrasonic measuring device 8 also includes a calculation module 10 (software) which is implemented here in the microcontroller 5a of the processing unit 5. The calculation module 10 performs the flow rate evaluations.

[0040] The upstream transducer 9a and the downstream transducer 9b are advantageously (but not necessarily) matched. Both the upstream transducer 9a and the downstream transducer 9b are piezoelectric transducers.

[0041] Each transducer 9a, 9b successively plays the role of an emitter and a receiver of ultrasonic signals.

[0042] The processing unit 5 generates an electrical excitation signal and provides this signal to the transmitter. The transmitter then generates an ultrasonic signal. The receiver receives the ultrasonic signal after it has traveled through the water along a predefined path.

[0043] The first predefined path is a direct path, inclined relative to a longitudinal axis X1 of duct 4 (the first predefined path could also be parallel to said axis X1). The first predefined path could also be an indirect path: the ultrasonic signals would then be reflected against the inner wall of duct 4 (possibly against reflectors located on the inner wall).

[0044] The first predefined path has a first length L1, which is known very precisely.

[0045] The upstream transducer 9a and the downstream transducer 9b are notably connected to the CAN 6 which digitizes the signals produced by said transducers.

[0046] Thus, the processing unit 5 first applies the electrical excitation signal to the terminals of the upstream transducer 9a so that the latter generates an upstream ultrasonic signal Sm in the conduit 4. The processing unit 5 acquires a downstream electrical signal produced by the downstream transducer 9b when the latter receives the upstream ultrasonic signal Sm.

[0047] Then, the processing unit 5 applies the electrical excitation signal to the terminals of the downstream transducer 9b so that the latter generates a downstream ultrasonic signal Sv in the conduit 4. The processing unit 5 acquires an upstream electrical signal produced by the upstream transducer 9a when the latter receives the downstream ultrasonic signal Sv.

[0048] Calculation module 10 analyzes the downstream electrical signal and the upstream electrical signal to evaluate a water velocity in conduit 4, then evaluates, from the water velocity, the water flow rate in conduit 4.

[0049] The meter 1 includes at least one pressure sensor, in this case two pressure sensors: an upstream pressure sensor 11a, which is positioned on the upstream end side of the conduit 4, and a downstream pressure sensor 11b, which is positioned on the downstream end side of the conduit 4.

[0050] The upstream pressure sensor 11a and the downstream pressure sensor 11b are connected to the processing unit 5. The upstream pressure sensor 11a and the downstream pressure sensor 11b are in particular connected to the CAN 6 which digitizes the measurements produced by said sensors.

[0051] The counter 1 further includes an emitter 12 arranged to emit a light signal Sl into the conduit 4, and a receiver 14 arranged to receive the light signal Sl after it has traveled a second predefined path in the conduit 4 (and therefore in the water).

[0052] The second predefined path extends along a second direction X2 perpendicular to a first direction (axis X1) along which the water flows.

[0053] The second predefined path has a second length L2, which is known very precisely.

[0054] The light signal Sl here is an infrared signal. The wavelength of the light signal Sl is, for example, equal to 860nm.

[0055] The emitter 12 is here a light-emitting diode (LED) and the receiver 14 is a photodiode.

[0056] With reference to the figure 2 , a first hole 15a and a second hole 15b, through, are formed in the thickness e of the wall of the conduit 4. The first hole 15a and the second hole 15b are located on the conduit 4 at diametrically opposite positions.

[0057] The LED 12 and the photodiode 14 each extend at least partially through one of the holes 15a, 15b.

[0058] The LED 12 is encapsulated in a cylindrical housing with a rounded end. The rounded end incorporates a lens. The housing is transparent or translucent to infrared light. The housing is made of epoxy resin.

[0059] LED 12 is inserted into the first hole 15a so that the end of LED 12, corresponding to the rounded end, protrudes inside the conduit 4.

[0060] Sealing is ensured by a first seal 16a which extends around the housing of the LED 12, being positioned between the housing of the LED 12 and the wall of the conduit 4 at the level of the first hole 15a.

[0061] Photodiode 14 is also encapsulated in a cylindrical housing with a rounded end. The rounded end here includes a lens.

[0062] The photodiode 14 is inserted into the second hole 15b opposite the LED 12 so that the end of the photodiode 14, corresponding to the rounded end, protrudes inside the conduit 4. Sealing is ensured by a second gasket 16b which extends around the housing of the photodiode 14, being positioned between the housing of the photodiode 14 and the wall of the conduit 4 at the level of the second hole 15b.

[0063] LED 12 and photodiode 14 are connected to processing unit 5.

[0064] The processing unit 5 can activate the LED 12 so that it emits the light signal Sl, and acquire the electrical signal Se occurs through the photodiode 14 when it receives the light signal Sl.

[0065] Photodiode 14 is connected to the CAN 6 of the microcontroller 5 which digitizes the electrical signal produced by photodiode 14.

[0066] Note that LED 12 and photodiode 14 are positioned here downstream of upstream transducer 9a and downstream transducer 9b of ultrasonic measuring device 8. This ensures that these components do not interfere with the metrological measurement of water flow carried out by the ultrasonic measuring device 8.

[0067] Treatment unit 5 evaluates qualitative parameters representative of the quality of the water supply.

[0068] The parameters of water quality measurement include, first and foremost, the turbidity of the water.

[0069] The processing unit 5 therefore controls the LED 12 so that it emits the light signal Sl into the conduit 4, and acquires the electrical signal Se produced by the photodiode 14. The processing unit 5 is thus able to determine the amount of light received by the photodiode 14. The processing unit 5 evaluates the turbidity of the water from said electrical signal Se.

[0070] The electrical signal Se is an electric current. The turbidity evaluated by the processing unit 5 is inversely proportional to said electric current.

[0071] Turbidity is expressed in NTU (for Nephelometric Turbidity Unit), which is a unit that represents an order of magnitude in mg / L of TSS (Suspended Solids).

[0072] A calibration of the system including the LED 12 and the photodiode 14 integrated into the counter 1, is carried out at the factory.

[0073] Current measurements, for example, are taken at a frequency of one measurement per second.

[0074] To perform a turbidity measurement at time T, the processing unit 5 takes a predetermined number of measurements of the electrical signal generated by the photodiode 14 (with LED 12 activated). The predetermined number is, for example, 10, meaning 5 measurements before time T and 5 measurements after time T. The processing unit 5 calculates the average of these 10 current measurements to obtain an averaged current value. The processing unit 5 then produces a turbidity measurement from this averaged current value.

[0075] The parameters for water quality measurement also include water temperature.

[0076] The processing unit 5 evaluates the speed of sound (or speed of sound) in the water using the ultrasonic measuring device 8, and then evaluates the water temperature from the speed of sound.

[0077] The ultrasonic measuring device 8 allows the speed c of sound to be measured in the following way.

[0078] Calculation module 10 first determines the sum of flight times (Time of Flight, Or ToF) ultrasonic signals between the two transducers 9a, 9b : sTOF.

[0079] The sum of flight times sTOF is therefore equal to the sum: the time taken by the upstream ultrasonic signal Sm to travel the first predefined path between the upstream transducer 9a and the downstream transducer 9b, and the time taken by the downstream ultrasonic signal Sv to travel the first predefined path between the downstream transducer 9b and the upstream transducer 9a.

[0080] Processing unit 5 then evaluates the speed of sound using the following formula: c = 2 × L 1 sTOF , Or L 1 is the first length of the first predefined path.

[0081] Then, processing unit 5 uses the following formula to evaluate the water temperature from the speed of sound:

[0082] This equation has a positive solution which corresponds to the water temperature. T .

[0083] This method of assessing water temperature is highly advantageous, as it eliminates the need to integrate a temperature sensor into meter 1. The water temperature is measured using transducers 9a and 9b, which are already present in meter 1 for metrological measurements. Therefore, a highly relevant parameter for evaluating water supply quality is obtained at no additional cost.

[0084] The quality measurement parameters also include a pressure measured by one of the pressure sensors of the processing unit 5.

[0085] This refers specifically to upstream pressure P M measured by the upstream pressure sensor 11a.

[0086] The water quality measurement parameters must meet predefined conditions in the case of a water meter to comply with the expected supply quality. The predefined conditions are as follows: upstream pressure P M < 16 Bar; Water temperature T: o Between 0.1°C and 30°C (for a cold water meter); o Between 50°C and 70°C (for a hot water meter); Turbidité ≤ 5 NTU .

[0087] The quality measurement parameters further include a pressure value representative of a pressure difference between an upstream pressure measured by the upstream pressure sensor 11a and a downstream pressure measured by the downstream pressure sensor 11b.

[0088] The pressure value here is equal to: ΔP = P M − P V , Or P M is the upstream pressure and P V is the downstream pressure.

[0089] The pressure value ΔP This is the pressure drop due to meter 1 itself. It is therefore not strictly speaking a water quality parameter, capable of assessing the quality of the water supply, but rather a constraint that meter 1 must meet to comply with its technical and functional specifications. The channeling of the flow through meter 1 necessarily results in a slight pressure drop, but this must be limited.

[0090] The pressure drop ΔP must verify the following predefined condition: ΔP < 0.63 Bar .

[0091] The numerical values ​​used for the predefined conditions are programmable and can be modified according to regulatory requirements.

[0092] Processing unit 5 creates a daily table 17 which contains the periodically produced qualimetry measurements. The period is, for example, equal to a quarter of an hour (i.e., 96 measurements per day).

[0093] Table 17 is stored in one of the 5b memories. An example of Table 17 is provided in the appendix.

[0094] Table 17 therefore contains 96 lines of measurements taken every quarter of an hour (for example from 00:07:30 to 23:52:30).

[0095] At each quarter of an hour (sample) measurements are taken of upstream pressure, pressure loss, temperature and turbidity.

[0096] The processing unit 5 stores these values ​​here over a week (therefore seven daily tables 17, identical to the one provided in the appendix, including the table for the current day).

[0097] Processing unit 5 can transmit this data to a system external to meter 1 using communication module 7. For example, processing unit 5 receives a request from said system via communication module 7. In response to this request, processing unit 5 transmits the quality measurement parameters to the external system via communication module 7.

[0098] The external system is, for example, the IS (for Information System) of the water distributor and / or the network manager.

[0099] The IS produces, for example, a dedicated DLMS request, to which counter 1 responds by sending table 17.

[0100] Meter 1 can also send an alarm message to the water distributor, the network manager, or even the end user, when the quality of the water supply is not satisfactory (i.e., it does not meet the predefined conditions mentioned earlier).

[0101] The assessment of the water supply quality by the meter provides legal proof that the quality of the supply at the end user is as expected in terms of water temperature, pressure and turbidity.

[0102] Finally, it should be noted that, with regard to electricity distribution, quality measurement is defined in standard NF EN 61000-4-30. To date, there is no standard for fluid meters, and no one has thought to define supply quality in the case of water. Yet, it seems extremely relevant to do so. This is one of the aims of the present invention.

[0103] Of course, the invention is not limited to the embodiment described but encompasses any variant falling within the scope of the invention as defined by the claims.

[0104] The meter is not necessarily a water meter; it could be a meter for any other fluid: gas, oil, etc.

[0105] The LED and photodiode do not necessarily extend through holes formed in the thickness of the duct. They could be positioned outside the duct, opposite these holes, which could be covered, for example, by transparent or translucent surfaces (such as glass). Alternatively, they could be attached to the inner wall of the duct, or integrated into a measuring device itself embedded within the duct.

[0106] The emitter and receiver of the light signal are not necessarily an LED and a photodiode. They could be, for example, a laser diode and a phototransistor.

[0107] The light signal is not necessarily an infrared signal; it could belong to the visible spectrum, for example. Annexe

[0108] Types de mesures → Echantillons ↓ Pression Amont (Bar) ΔP (Bar) Perte de charge Température (°C) Turbidité (NTU) 1 XXX XXX YYY zzz 2 XXX XXX YYY zzz 3 XXX XXX YYY zzz ... ... ... ... ... 95 XXX XXX YYY zzz 96 XXX XXX YYY zzz

Claims

1. Fluid meter (1) comprising: - a conduit (4) in which the fluid circulates; - an ultrasonic measuring device (8) arranged to measure a flow rate of the fluid in said conduit, and comprising an upstream transducer (9a) arranged to generate an upstream ultrasonic signal (Sm) in the conduit (4), and a downstream transducer (9b) arranged to generate a downstream ultrasonic signal (Sv) in the conduit (4); characterized in that the fluid meter comprises: - an emitter (12) arranged to emit a light signal (Sl) into said conduit; - a receiver (14) arranged to receive the light signal after this has travelled a predefined path in said conduit, the emitter (12) and the receiver (14) being positioned downstream of the upstream transducer and of the downstream transducer of the ultrasonic measuring device (8); - a processing unit (5) arranged to acquire an electrical signal (Se) produced by the receiver, and to evaluate a turbidity of the fluid from said electrical signal.

2. Fluid meter according to claim 1, wherein the fluid circulates in the conduit in a first direction (X1), and wherein the predefined path extends in a second direction (X2), perpendicular to the first direction.

3. Fluid meter according to one of the preceding claims, wherein the light signal (Sl) is an infrared signal.

4. Fluid meter according to one of the preceding claims, wherein the emitter is a light-emitting diode and the receiver is a photodiode.

5. Fluid meter according to one of the preceding claims, wherein the conduit comprises two holes (15a, 15b), and wherein the emitter and the receiver each extend at least partially through one of the holes.

6. Fluid meter according to claim 5, wherein the two holes (15a, 15b) are located on the conduit at diametrically opposite positions.

7. Fluid meter according to one of the preceding claims, wherein the electrical signal (Se) is an electric current, and wherein the turbidity evaluated by the processing unit (5) is inversely proportional to said electric current.

8. Fluid meter according to one of the preceding claims, the processing unit (5) being arranged to evaluate qualimetry parameters representative of a quality of a fluid supply, said qualimetry parameters comprising the turbidity of the fluid.

9. Fluid meter according to claim 8, the qualimetry parameters further comprising a temperature of the fluid.

10. Fluid meter according to claims 7 and 9, the processing unit (5) being arranged to evaluate a speed of sound in the fluid by using the ultrasonic measuring device (8), then to evaluate the temperature of the fluid from the speed of sound.

11. Fluid meter according to one of claims 8 to 10, wherein the meter (1) comprises at least one pressure sensor (11a, 11b), the qualimetry parameters further comprising a pressure measured by said pressure sensor.

12. Fluid meter according to claim 11, wherein the meter (1) comprises an upstream pressure sensor (11a), positioned on a side of an upstream end of the conduit (4), and a downstream pressure sensor (11b), positioned on a side of a downstream end of the conduit, the qualimetry parameters further comprising a pressure value representative of a pressure difference between an upstream pressure measured by the upstream pressure sensor and a downstream pressure measured by the downstream pressure sensor.

13. Fluid meter according to one of claims 8 to 12, further comprising a communication module (7), the processing unit (5) being arranged to receive, via the communication module, a request emitted by a system external to the fluid meter, and to, in response to said request, transmit the qualimetry parameters to said system.

14. Measuring method, implemented in the processing unit (5) of a fluid meter (1) according to one of the preceding claims, comprising the steps of: - controlling the emitter (12) such that it emits the light signal (Sl) into the conduit (4); - acquiring the electrical signal (Se) produced by the receiver (14) ; - evaluating a turbidity of the fluid from said electrical signal.

15. Computer program comprising instructions which make the processing unit (5) of the fluid meter (1) according to one of the preceding claims execute the steps of the measuring method according to claim 14.

16. Computer-readable storage medium, on which the computer program according to claim 15 is stored.