WO2000068651A1 - Debitmetres massiques du type a fil resistif - Google Patents
Debitmetres massiques du type a fil resistif Download PDFInfo
- Publication number
- WO2000068651A1 WO2000068651A1 PCT/FR2000/001255 FR0001255W WO0068651A1 WO 2000068651 A1 WO2000068651 A1 WO 2000068651A1 FR 0001255 W FR0001255 W FR 0001255W WO 0068651 A1 WO0068651 A1 WO 0068651A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- flow meter
- fluid
- mass flow
- parameter
- wire
- Prior art date
Links
- 239000012530 fluid Substances 0.000 claims abstract description 26
- 238000001816 cooling Methods 0.000 claims abstract description 19
- 238000010438 heat treatment Methods 0.000 claims description 9
- 239000000523 sample Substances 0.000 claims description 9
- 239000007787 solid Substances 0.000 claims description 8
- 230000007257 malfunction Effects 0.000 claims description 3
- 239000000463 material Substances 0.000 claims description 3
- 239000002245 particle Substances 0.000 claims description 3
- 238000001514 detection method Methods 0.000 claims 1
- 238000005259 measurement Methods 0.000 description 4
- 238000006243 chemical reaction Methods 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- 239000004020 conductor Substances 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 239000004519 grease Substances 0.000 description 1
- 238000002347 injection Methods 0.000 description 1
- 239000007924 injection Substances 0.000 description 1
- 239000003350 kerosene Substances 0.000 description 1
- 238000003466 welding Methods 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
- G01F1/00—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow
- G01F1/68—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow by using thermal effects
- G01F1/696—Circuits therefor, e.g. constant-current flow meters
- G01F1/698—Feedback or rebalancing circuits, e.g. self heated constant temperature flowmeters
- G01F1/6986—Feedback or rebalancing circuits, e.g. self heated constant temperature flowmeters with pulsed heating, e.g. dynamic methods
Definitions
- the present invention relates to mass flowmeters of the resistive wire type.
- the applicant has already proposed in its patent application
- FR-2.728.071 a hot wire flow meter capable of measuring a mass flow.
- An object of the invention is to propose a mass flow meter comprising means making it possible to detect this drift.
- Another object of the invention is to propose a mass flow meter comprising means making it possible to detect operating anomalies of the electronics associated with said flow meter.
- Such a treatment is not very effective and does not make it possible to determine a possible drift or possible anomalies sufficiently early. It also does not allow a determination to correct any drifts or anomalies
- the invention proposes, for its part, a mass flow meter, of the type comprising a heating probe placed in the path of a fluid the flow of which it is desired to measure, means for applying to said probe pulses of current, measuring means for determining its cooling rate between said pulses, characterized in that it comprises processing means capable of determining a characteristic parameter of at least a portion of a curve cooling of the fluid and to deduce from this parameter information relating to a possible drift or operating anomaly.
- the processing means determine the parameter at the end of the generation of a current pulse in the absence of circulation of fluid and include means for generating such a pulse, when a phase start is detected. use of the flow meter, before the circulation of the fluid is established.
- the processing means comprise means for determining a parameter characteristic of a first cooling phase during which the heating probe cools by conduction through the material which composes it, as well as through its sheath and any oily, greasy or solid deposits, said processing means also comprising means for deducing from this parameter information relating to a possible drift due to said oily, greasy or solid deposits.
- the processing means may include means for determining a characteristic parameter of a second cooling phase during which the heating probe also cools by conduction in the fluid, but at zero fluid flow rate, not by convection, as well as means for deducing from this parameter information relating to a possible malfunction of the electronics of said flow meter.
- FIG. 1 is a view in axial vertical section of a hot wire mass flow meter
- - Figure 2 is a cross-sectional view of the flowmeter of Figure 1
- - Figure 3 is a diagram of the temperature of the wire versus time
- - Figure 4 is a schematic perspective representation of a profile body in which the wire of a flow meter according to the invention can be received.
- FIG. 1 There is shown in Figures 1 and 2 a hot wire mass flow meter which is for example of the type described in patent application FR-2.728.071 of the applicant, which may advantageously be referred to.
- This flow meter comprises a generally cylindrical hollow body 10, in which the fluid whose mass flow is to be measured circulates.
- This body 10 is connected to pipes for supplying fluid and for leaving fluid by suitable leaktight means.
- a resistive wire 18 for example constituted by a resistive conductor bent at 180 ° at its lower end and extending in duplicate in a sheath.
- the lower end of said wire 18 is crimped into a cylindrical ring 20 welded into a bore in the body 10.
- the resistive wire passes electrically insulating through a central bore of a mount 16 fixed in another bore of the body 10 by welding, said wire 18 being fixed to said mount 16.
- a connector 12 for connecting said wire 18 to an electronic processing unit 30.
- a heating of the resistive wire 18 is established by applying well defined current pulses to it and the slope of the wire cooling curve is studied when between the successive pulses, only a small, non-significant current, the crosses.
- Knowing this slope allows the processing unit 30 to calculate the mass flow rate of the fluid, said slope being in fact directly a function of said mass flow rate.
- the electronic circuit of the flow meter is designed so that the control unit 30 can know at any time on the one hand the voltage U across the terminals of the wire 18, and on the other hand the current I which passes through it.
- the instantaneous value of its resistance R U / l, and therefore the instantaneous value of its temperature, the resistance varying as a function of the temperature according to a monotonic law which is known beforehand.
- the flowmeter does not require any reference, unlike the majority of previously known systems.
- the flow meter is insensitive to variations in the temperature of the fluid whose flow rate is to be measured.
- the processing unit 30 includes clocked means for applying current pulses to the wire, each time with the same constant current value, according to a well-defined duty cycle. It also includes means capable, during each period separating two successive current pulses, of acquiring the temperature of the wire by measuring its resistance. To be able to carry out this measurement, it is necessary to circulate a very low constant current in the wire, the value of this current being chosen so as not to influence the thermal behavior of the wire during its cooling. For example, the current is chosen so as to generate a power of a few milliwatts, to be compared to a few tens of watts during the current pulses proper. Thus the temperature of the wire during its cooling is directly proportional to the voltage across its terminals.
- the processing unit 30 includes a circuit for deriving this voltage as a function of time.
- the derivative thus obtained is a function of the mass flow and the processing unit 30 includes conversion means which determine the mass flow as a function of the voltage derivative.
- the unit 30 includes storage means in which conversion tables are stored.
- the processing unit 30 includes means for comparing the responses obtained in voltage or in temperature with theoretical responses previously stored. For example, before any injection of fluid (kerosene for example) into the body 10, the processing unit 30 sends a current pulse in the conductive wire 18. The resulting temperature response is compared to a theoretical response, which is that of the flowmeter at the factory, in the absence of flow.
- a theoretical response which is that of the flowmeter at the factory, in the absence of flow.
- the processing unit 30 determines on the cooling curve two phases I and II separated by a discontinuity in the cooling mode.
- the cooling curve comprises two distinct portions:
- a first phase where the heat generated by the current pulse is only conducted by the material which constitutes the wire 18, by the sheath thereof and possibly by the oily, greasy or solid deposits around said sheath (phase I on Figure 3).
- the cooling curves during both of these two phases are portions of curves in exp (- 1 / ⁇ i) and exp (- 1 / ⁇ 2 ), where ⁇ and ⁇ 2 are time constants which are characteristic of both phases.
- the parameter ⁇ i is constant as a function of the mass flow rate.
- the time constant ⁇ 2 is decreasing as a function of the mass flow.
- the determination of the time constant ⁇ i by the processing unit 30 when a current pulse is sent in the conductive wire 18 in the absence of circulation of fluid in the body 10 allows the processing unit 30 to detect the presence of oily, greasy or solid deposits.
- the unit 30 corrects the parameters of the processing that it implements to integrate the drift due to these deposits.
- the processing unit determines the parameter ⁇ 2 . It compares the value obtained for this parameter ⁇ 2 in the absence of circulation of fluid in the body 10 at a theoretical value. In the case where the difference between this theoretical value and the value determined for the parameter ⁇ 2 is greater than a given threshold, the processing unit 30 deduces therefrom the existence of an anomaly in the operation of the electronics associated with the flow meter.
- the wire 18 of the flow meter can be received in a profile of the type which has been described in patent application FR 91 10845 of the applicant, to which one can advantageously refer.
- a profiled body has been represented in FIG. 4 in which it has been referenced by C. It has a shape of an airplane wing type which may or may not be symmetrical.
- An opening O passes through said profiled body C. the wire 18 extends in the length of this opening.
- the shape of said opening O and the incidence of said profiled body C in the fluid flow being such that the boundary layer and the flow to be measured penetrate into said opening O so as to avoid or reduce the impacts of particles (of solid in the liquid fluid; solid and liquid in the case of a gaseous fluid).
Landscapes
- Physics & Mathematics (AREA)
- Fluid Mechanics (AREA)
- General Physics & Mathematics (AREA)
- Measuring Volume Flow (AREA)
- Glass Compositions (AREA)
- Investigating Or Analyzing Materials By The Use Of Fluid Adsorption Or Reactions (AREA)
- Paper (AREA)
- Photoreceptors In Electrophotography (AREA)
Abstract
Description
Claims
Priority Applications (7)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US09/979,692 US6813945B1 (en) | 1999-05-11 | 2000-05-10 | Resistive wire mass flow meters |
JP2000617393A JP2002544500A (ja) | 1999-05-11 | 2000-05-10 | 抵抗線質量流量計 |
CA002374637A CA2374637A1 (fr) | 1999-05-11 | 2000-05-10 | Debitmetres massiques du type a fil resistif |
EP00927324A EP1177415B1 (fr) | 1999-05-11 | 2000-05-10 | Debitmetres massiques du type a fil resistif |
DK00927324T DK1177415T3 (da) | 1999-05-11 | 2000-05-10 | Masseflowmåler af typen med modstandstråd |
DE60018404T DE60018404T2 (de) | 1999-05-11 | 2000-05-10 | Massendurchflussmesser mit widerstandsdraht |
AT00927324T ATE290203T1 (de) | 1999-05-11 | 2000-05-10 | Massendurchflussmesser mit widerstandsdraht |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
FR9905987A FR2793553B1 (fr) | 1999-05-11 | 1999-05-11 | Debitmetres massiques du type a fil resistif |
FR99/05987 | 1999-05-11 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2000068651A1 true WO2000068651A1 (fr) | 2000-11-16 |
Family
ID=9545453
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/FR2000/001255 WO2000068651A1 (fr) | 1999-05-11 | 2000-05-10 | Debitmetres massiques du type a fil resistif |
Country Status (10)
Country | Link |
---|---|
US (1) | US6813945B1 (fr) |
EP (1) | EP1177415B1 (fr) |
JP (1) | JP2002544500A (fr) |
AT (1) | ATE290203T1 (fr) |
CA (1) | CA2374637A1 (fr) |
DE (1) | DE60018404T2 (fr) |
ES (1) | ES2235874T3 (fr) |
FR (1) | FR2793553B1 (fr) |
PT (1) | PT1177415E (fr) |
WO (1) | WO2000068651A1 (fr) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP1615002A1 (fr) | 2004-07-09 | 2006-01-11 | General Electric Company | Aube et procédé pour la mesure d'une propriété physique d'un écoulement d'air |
US7915567B2 (en) | 2003-06-27 | 2011-03-29 | Auxitrol S.A. | Heated resistance especially for heating a solid part such as a temperature probe and/or a pressure probe |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE102006045660B4 (de) | 2006-09-27 | 2023-06-22 | Robert Bosch Gmbh | Steckfühler mit Strömungsleitelementen |
US20180174486A1 (en) * | 2016-12-21 | 2018-06-21 | GM Global Technology Operations LLC | Impairment detection device with performance feedback system and method of operating the same |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4335605A (en) * | 1980-05-14 | 1982-06-22 | Thermal Instrument Company | Mass flow meter |
EP0210509A1 (fr) * | 1985-08-02 | 1987-02-04 | Schmidt Feintechnik Gmbh | Procédé pour mesurer les propriétés d'un fluide et élément de palpeur pour la mise en oeuvre de ce procédé |
FR2680872A1 (fr) * | 1991-09-02 | 1993-03-05 | Auxitrol Sa | Sonde pour la mesure de parametres physiques d'un flux de fluide. |
FR2728071A1 (fr) * | 1994-12-07 | 1996-06-14 | Auxitrol Sa | Debitmetre massique a fil chaud |
Family Cites Families (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5347876A (en) * | 1992-01-07 | 1994-09-20 | Gas Research Institute | Gas flowmeter using thermal time-of-flight principle |
UA40010C2 (uk) * | 1997-07-29 | 2001-07-16 | Гасконтрол Б.В. | Спосіб вимірювання величини витрати газу і газовий лічильник для нього |
US6023969A (en) * | 1997-09-17 | 2000-02-15 | Feller; Murray F. | Flow modulated mass flow sensor |
-
1999
- 1999-05-11 FR FR9905987A patent/FR2793553B1/fr not_active Expired - Fee Related
-
2000
- 2000-05-10 EP EP00927324A patent/EP1177415B1/fr not_active Expired - Lifetime
- 2000-05-10 DE DE60018404T patent/DE60018404T2/de not_active Expired - Fee Related
- 2000-05-10 JP JP2000617393A patent/JP2002544500A/ja active Pending
- 2000-05-10 PT PT00927324T patent/PT1177415E/pt unknown
- 2000-05-10 US US09/979,692 patent/US6813945B1/en not_active Expired - Fee Related
- 2000-05-10 WO PCT/FR2000/001255 patent/WO2000068651A1/fr active IP Right Grant
- 2000-05-10 ES ES00927324T patent/ES2235874T3/es not_active Expired - Lifetime
- 2000-05-10 AT AT00927324T patent/ATE290203T1/de not_active IP Right Cessation
- 2000-05-10 CA CA002374637A patent/CA2374637A1/fr not_active Abandoned
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4335605A (en) * | 1980-05-14 | 1982-06-22 | Thermal Instrument Company | Mass flow meter |
EP0210509A1 (fr) * | 1985-08-02 | 1987-02-04 | Schmidt Feintechnik Gmbh | Procédé pour mesurer les propriétés d'un fluide et élément de palpeur pour la mise en oeuvre de ce procédé |
FR2680872A1 (fr) * | 1991-09-02 | 1993-03-05 | Auxitrol Sa | Sonde pour la mesure de parametres physiques d'un flux de fluide. |
FR2728071A1 (fr) * | 1994-12-07 | 1996-06-14 | Auxitrol Sa | Debitmetre massique a fil chaud |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US7915567B2 (en) | 2003-06-27 | 2011-03-29 | Auxitrol S.A. | Heated resistance especially for heating a solid part such as a temperature probe and/or a pressure probe |
EP1615002A1 (fr) | 2004-07-09 | 2006-01-11 | General Electric Company | Aube et procédé pour la mesure d'une propriété physique d'un écoulement d'air |
Also Published As
Publication number | Publication date |
---|---|
US6813945B1 (en) | 2004-11-09 |
EP1177415B1 (fr) | 2005-03-02 |
FR2793553B1 (fr) | 2001-08-10 |
CA2374637A1 (fr) | 2000-11-16 |
ES2235874T3 (es) | 2005-07-16 |
FR2793553A1 (fr) | 2000-11-17 |
DE60018404D1 (de) | 2005-04-07 |
JP2002544500A (ja) | 2002-12-24 |
DE60018404T2 (de) | 2005-12-29 |
EP1177415A1 (fr) | 2002-02-06 |
PT1177415E (pt) | 2005-06-30 |
ATE290203T1 (de) | 2005-03-15 |
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