EP1218955A1 - Determination of alcohol concentration in an electrolyte of fuel cells - Google Patents
Determination of alcohol concentration in an electrolyte of fuel cellsInfo
- Publication number
- EP1218955A1 EP1218955A1 EP00967565A EP00967565A EP1218955A1 EP 1218955 A1 EP1218955 A1 EP 1218955A1 EP 00967565 A EP00967565 A EP 00967565A EP 00967565 A EP00967565 A EP 00967565A EP 1218955 A1 EP1218955 A1 EP 1218955A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- alcohol
- mixture
- constriction
- fuel cells
- concentration
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
- 239000000446 fuel Substances 0.000 title claims abstract description 33
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 title claims abstract description 29
- 239000003792 electrolyte Substances 0.000 title description 6
- 239000000203 mixture Substances 0.000 claims abstract description 30
- 238000000034 method Methods 0.000 claims abstract description 11
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 claims description 60
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 16
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 6
- 239000007788 liquid Substances 0.000 description 4
- 229910002092 carbon dioxide Inorganic materials 0.000 description 3
- 239000001569 carbon dioxide Substances 0.000 description 3
- 239000012528 membrane Substances 0.000 description 3
- LYCAIKOWRPUZTN-UHFFFAOYSA-N Ethylene glycol Chemical compound OCCO LYCAIKOWRPUZTN-UHFFFAOYSA-N 0.000 description 2
- 238000011088 calibration curve Methods 0.000 description 2
- 238000005086 pumping Methods 0.000 description 2
- 229910001369 Brass Inorganic materials 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 150000007513 acids Chemical class 0.000 description 1
- 150000001298 alcohols Chemical class 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 239000010951 brass Substances 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000006056 electrooxidation reaction Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 239000012530 fluid Substances 0.000 description 1
- WGCNASOHLSPBMP-UHFFFAOYSA-N hydroxyacetaldehyde Natural products OCC=O WGCNASOHLSPBMP-UHFFFAOYSA-N 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- -1 methanol Chemical class 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- BDERNNFJNOPAEC-UHFFFAOYSA-N propan-1-ol Chemical compound CCCO BDERNNFJNOPAEC-UHFFFAOYSA-N 0.000 description 1
- 239000000376 reactant Substances 0.000 description 1
- 238000002407 reforming Methods 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N11/00—Investigating flow properties of materials, e.g. viscosity, plasticity; Analysing materials by determining flow properties
- G01N11/02—Investigating flow properties of materials, e.g. viscosity, plasticity; Analysing materials by determining flow properties by measuring flow of the material
- G01N11/04—Investigating flow properties of materials, e.g. viscosity, plasticity; Analysing materials by determining flow properties by measuring flow of the material through a restricted passage, e.g. tube, aperture
- G01N11/08—Investigating flow properties of materials, e.g. viscosity, plasticity; Analysing materials by determining flow properties by measuring flow of the material through a restricted passage, e.g. tube, aperture by measuring pressure required to produce a known flow
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M8/00—Fuel cells; Manufacture thereof
- H01M8/04—Auxiliary arrangements, e.g. for control of pressure or for circulation of fluids
- H01M8/04082—Arrangements for control of reactant parameters, e.g. pressure or concentration
- H01M8/04186—Arrangements for control of reactant parameters, e.g. pressure or concentration of liquid-charged or electrolyte-charged reactants
- H01M8/04194—Concentration measuring cells
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/30—Hydrogen technology
- Y02E60/50—Fuel cells
Definitions
- the invention relates to a method for determining the alcohol concentration in the alcohol / water mixture of fuel cells operated with this mixture, in particular direct methanol fuel cells.
- the invention further relates to a device for performing this method.
- a measuring device for determining the concentration of low molecular weight alcohols, such as methanol, in water or acids is known from EP 0 684 469 A1.
- This meter has a porous anode for the electrochemical oxidation of alcohol, one
- Cathode for the electrochemical reduction of oxygen an ion-conducting membrane arranged between the anode and cathode and a diffusion-limiting membrane, which is arranged on the side of the anode facing away from the ion-conducting membrane.
- the measuring device which essentially represents a fuel cell, is arranged in the fuel line, for example, and is kept potentiostatically at a defined cell voltage. Depending on the alcohol concentration, a current flows through this fuel cell, the size of which can be used to infer the concentration using a calibration curve. Such a procedure is relatively complex since current and voltage have to be measured or checked.
- DMFC Direct Methanol Fuel Cell
- the fuel methanol is directly electrochemically oxidized, ie implemented without the intermediate step of reforming (see, for example, Shoes M. Waidhas in K. Ledjeff (ed.) "Fuel cells: development, technology, application", CF Müller Verlag GmbH, Heidelberg 1995, pages 137 to 156).
- K. Ledjeff ed.
- the object of the invention is to provide a method for determining the alcohol concentration in the alcohol / water mixture of fuel cells operated with this mixture fulfills all the requirements placed on such a determination method. Above all, it is necessary that the concentration can be determined continuously and in parallel with the operation of the fuel cells or the stack, and that no disturbances occur due to carbon dioxide present in the electrolyte.
- the fuel is an alcohol.
- the alcohol is in particular methanol, ethanol, propanol or glycol.
- the method according to the invention takes advantage of the fact that the viscosity of an alcohol / water mixture depends significantly on the composition of the mixture, i.e. the viscosity changes with the alcohol content.
- the viscosity at 20 ° C. with a methanol content of 0 to 16% by mass increases from 1.0 to 1.5 (see: CRC Handbook of Chemistry and Physics, 69th edition, 1988, page D-238).
- the invention applies Hagen-Poiseuille's law when determining the alcohol concentration (in particular in the anode circuit of direct methanol fuel cells).
- the constriction is built directly into the anode circuit and the alcohol / water mixture is pressed through the constriction by means of the circulating pump, which already has the value dV / dt (flow rate). In this embodiment, however, the entire mixture has to be conveyed through the constriction, which could mean an increased expenditure of energy.
- the methanol / water mixture has a temperature in the range from 80 to 110 ° C., which could have an unfavorable effect on the viscosity differences.
- Amount of alcohol / water mixture must be pressed through the narrow point. This small amount, which is a has lower heat capacity, can be thermostatted to low temperatures if necessary. In this embodiment, however, an additional measurement of the flow rate (dV / dt) of the liquid in the bypass must be carried out.
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- Chemical & Material Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- General Chemical & Material Sciences (AREA)
- Physics & Mathematics (AREA)
- Sustainable Energy (AREA)
- Manufacturing & Machinery (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- Engineering & Computer Science (AREA)
- Sustainable Development (AREA)
- Health & Medical Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Fuel Cell (AREA)
Abstract
Description
Beschreibung description
Bestimmung der Alkoholkonzentration im Elektrolyt von BrennstoffzellenDetermination of the alcohol concentration in the electrolyte of fuel cells
Die Erfindung betrifft ein Verfahren zur Bestimmung der Alkoholkonzentration im Alkohol/Wasser-Gemisch von mit diesem Gemisch betriebenen Brennstoffzellen, insbesondere Direkt- Methanol-Brennstoffzellen. Ferner betrifft die Erfindung eine Vorrichtung zur Durchführung dieses Verfahrens.The invention relates to a method for determining the alcohol concentration in the alcohol / water mixture of fuel cells operated with this mixture, in particular direct methanol fuel cells. The invention further relates to a device for performing this method.
Zur Einhaltung der optimalen Betriebsparameter bei Brennstoffzellen, die mit flüssigen Brennstoffen betrieben werden, ist es erforderlich, die Brennstoffkonzentration zu regeln. Hierzu muss die aktuelle Konzentration bestimmt werden.In order to maintain the optimal operating parameters for fuel cells that are operated with liquid fuels, it is necessary to regulate the fuel concentration. To do this, the current concentration must be determined.
Aus der EP 0 684 469 AI ist ein Messgerät zur Konzentrations- bestimmung niedermolekularer Alkohole, wie Methanol, in Wasser oder Säuren bekannt. Dieses Messgerät weist eine poröse Anode zur elektrochemischen Oxidation von Alkohol, eineA measuring device for determining the concentration of low molecular weight alcohols, such as methanol, in water or acids is known from EP 0 684 469 A1. This meter has a porous anode for the electrochemical oxidation of alcohol, one
Kathode zur elektrochemischen Reduktion von Sauerstoff, eine zwischen Anode und Kathode angeordnete ionenleitende Membran und eine diffusionsbegrenzende Membran auf, die auf der von der ionenleitenden Membran abgewandten Seite der Anode ange- ordnet ist. Das Messgerät, das quasi eine Brennstoffzelle darstellt, wird beispielsweise in der Brennstoffleitung angeordnet und potentiostatisch auf einer definierten Zellspannung gehalten. Je nach der Alkoholkonzentration fließt durch diese Brennstoffzelle ein Strom, aus dessen Größe - mittels einer Eichkurve - auf die Konzentration geschlossen werden kann. Eine derartige Vorgehensweise ist relativ aufwendig, da Strom und Spannung gemessen bzw. kontrolliert werden müssen.Cathode for the electrochemical reduction of oxygen, an ion-conducting membrane arranged between the anode and cathode and a diffusion-limiting membrane, which is arranged on the side of the anode facing away from the ion-conducting membrane. The measuring device, which essentially represents a fuel cell, is arranged in the fuel line, for example, and is kept potentiostatically at a defined cell voltage. Depending on the alcohol concentration, a current flows through this fuel cell, the size of which can be used to infer the concentration using a calibration curve. Such a procedure is relatively complex since current and voltage have to be measured or checked.
Bei sogenannten Direkt-Methanol-Brennstoffzellen (DMFC = Direct Methanol Fuel Cell) wird der Brennstoff Methanol direkt elektrochemisch oxidiert, d.h. ohne den Zwischenschritt einer Reformierung umgesetzt (siehe dazu beispiels- weise M. Waidhas in K. Ledjeff (Hrsg.) „Brennstoffzellen: Entwicklung, Technologie, Anwendung", C.F. Müller Verlag GmbH, Heidelberg 1995, Seiten 137 bis 156) . Um bei einer DMFC den optimalen Arbeitspunkt zu erreichen, ist es notwendig, mit verdünntem Brennstoff im Überschuss zu arbeiten.In so-called direct methanol fuel cells (DMFC = Direct Methanol Fuel Cell), the fuel methanol is directly electrochemically oxidized, ie implemented without the intermediate step of reforming (see, for example, Weise M. Waidhas in K. Ledjeff (ed.) "Fuel cells: development, technology, application", CF Müller Verlag GmbH, Heidelberg 1995, pages 137 to 156). To achieve the optimal working point with a DMFC, it is necessary to to work with excess fuel.
Zum wirtschaftlichen Betrieb eines Direkt-Methanol-Brennstoffzellensystems („Stack") ist es erforderlich, dass der überschüssige Brennstoff und das Wasser, das nicht nur als Lösemittel, sondern auch als Reaktant fungiert (Anodenreaktion: CH3OH + H20 → C02 + 6 H+ + 6 e~) , im Kreislauf geführt werden. Dies bedeutet, dass das Methanol/Wasser-Gemisch nach Verlassen des Stacks (und nach Abtrennung des bei der Oxida- tion des Methanols entstandenen Kohlendioxids) erneut der Anode zugeführt wird. Da für den Betrieb eines DMFC-Stacks eine bestimmte Methanolkonzentration notwendig ist, muss die Methanolkonzentration im Anodenkreislauf gemessen und bei zu niedriger Konzentration die fehlende Brennstoffmenge zudosiert werden.For the economical operation of a direct methanol fuel cell system (“stack”), it is necessary that the excess fuel and the water, which not only function as a solvent, but also as a reactant (anode reaction: CH 3 OH + H 2 0 → C0 2 + 6 H + + 6 e ~ ), which means that the methanol / water mixture is returned to the anode after leaving the stack (and after separating off the carbon dioxide formed during the oxidation of the methanol). Since a certain methanol concentration is necessary for the operation of a DMFC stack, the methanol concentration in the anode circuit must be measured and, if the concentration is too low, the missing amount of fuel must be added.
Zur Online-Bestimmung der Brennstoffkonzentration im Elektrolyt von Brennstoffzellen wurde bereits vorgeschlagen, durch Messung der frequenzabhängigen Kapazität einer vom Brennstoff/Elektrolyt-Gemisch durchflossenen Messzelle die Dielek- trizitätskonstante des Gemisches zu bestimmen, deren Größe von der Brennstoffkonzentration abhängig ist (deutsche Patentanmeldung Akt.Z. 199 38 790.7). Hierbei ist eine genaue Kontrolle von Druck und Temperatur erforderlich, das Mess- gerät muss sehr genau arbeiten. Diese Art der Brennstoff- bestimmung ist außerdem empfindlich gegenüber im Elektrolyt gelöstem Kohlendioxid, das beispielsweise im Anodenkreislauf eines mit flüssigem Brennstoff betriebenen DMFC-Stacks stets vorhanden ist.For online determination of the fuel concentration in the electrolyte of fuel cells, it has already been proposed to determine the dielectric constant of the mixture, the size of which depends on the fuel concentration, by measuring the frequency-dependent capacitance of a measuring cell through which the fuel / electrolyte mixture flows (German patent application Akt.Z 199 38 790.7). Precise control of pressure and temperature is required here, the measuring device must work very precisely. This type of fuel determination is also sensitive to carbon dioxide dissolved in the electrolyte, which is always present, for example, in the anode circuit of a DMFC stack operated with liquid fuel.
Aufgabe der Erfindung ist es, ein Verfahren zur Bestimmung der Alkoholkonzentration im Alkohol/Wasser-Gemisch von mit diesem Gemisch betriebenen Brennstoffzellen anzugeben, das sämtliche der an eine derartige Bestimmungsmethode gestellten Anforderungen erfüllt. Hierbei ist vor allem erforderlich, dass die Konzentrationsbestimmung kontinuierlich und parallel zum Betrieb der Brennstoffzellen bzw. des Stacks erfolgen kann und keine Störungen durch im Elektrolyt vorhandenes Kohlendioxid auftreten.The object of the invention is to provide a method for determining the alcohol concentration in the alcohol / water mixture of fuel cells operated with this mixture fulfills all the requirements placed on such a determination method. Above all, it is necessary that the concentration can be determined continuously and in parallel with the operation of the fuel cells or the stack, and that no disturbances occur due to carbon dioxide present in the electrolyte.
Dies wird erfindungsgemäß dadurch erreicht, dass das Alkohol/ Wasser-Gemisch durch eine Engstelle gepumpt wird, dass der Differenzdruck zwischen Eingang und Ausgang der Engstelle sowie gegebenenfalls die Fließgeschwindigkeit des Gemisches durch die Engstelle gemessen wird und daraus die Alkohol- konzentration bestimmt wird.This is achieved according to the invention in that the alcohol / water mixture is pumped through a constriction, the differential pressure between the inlet and outlet of the constriction and, if appropriate, the flow rate of the mixture through the constriction is measured and the alcohol concentration is determined therefrom.
Bei diesem Verfahren ist der Brennstoff ein Alkohol. Der Alkohol ist dabei insbesondere Methanol, Ethanol, Propanol oder Glykol .In this process, the fuel is an alcohol. The alcohol is in particular methanol, ethanol, propanol or glycol.
Beim Verfahren nach der Erfindung wird die Tatsache aus- genutzt, dass die Viskosität eines Alkohol/Wasser-Gemisches deutlich von der Zusammensetzung des Gemisches abhängt, d.h. die Viskosität ändert sich mit dem Alkoholgehalt . So steigt beispielsweise bei einem Methanol/Wasser-Gemisch die relative Viskosität bei 20°C bei einem Methanolgehalt von 0 bis 16 Masse-% (5 mol/1) von 1,0 auf 1,5 (siehe dazu: CRC Handbook of Chemistry and Physics, 69. Auflage, 1988, Seite D-238) .The method according to the invention takes advantage of the fact that the viscosity of an alcohol / water mixture depends significantly on the composition of the mixture, i.e. the viscosity changes with the alcohol content. For example, in the case of a methanol / water mixture, the relative viscosity at 20 ° C. with a methanol content of 0 to 16% by mass (5 mol / 1) increases from 1.0 to 1.5 (see: CRC Handbook of Chemistry and Physics, 69th edition, 1988, page D-238).
Die Erfindung wendet - bei der Bestimmung der Alkoholkonzentration (insbesondere im Anodenkreislauf von Direkt-Methanol- Brennstoffzellen) - das Hagen-Poiseuillesche Gesetz an. Dieses Gesetz beschreibt den Zusammenhang zwischen der Fließgeschwindigkeit dV/dt (V = Volumen, t = Zeit) eines Fluids der Viskosität η, beispielsweise einer Lösung, durch ein Rohr bzw. einen Schlauch mit der Länge L und dem Radius R einer- seits und der Druckdifferenz Δp = Pι-p2 zwischen Eingang und Ausgang des Rohres andererseits: dV/dt = [π (pι-p2) R4] / [8ηL] . The invention applies Hagen-Poiseuille's law when determining the alcohol concentration (in particular in the anode circuit of direct methanol fuel cells). This law describes the relationship between the flow velocity dV / dt (V = volume, t = time) of a fluid of viscosity η, for example a solution, through a pipe or hose with the length L and the radius R on the one hand and the Pressure difference Δp = Pι-p 2 between inlet and outlet of the tube, on the other hand: dV / dt = [π (pι-p 2 ) R 4 ] / [8ηL].
Bei Versuchen zur Durchführung des Verfahrens nach der Erfindung wurden Methanol/Wasser-Gemische unterschiedlicher Konzentration bei 25°C mit konstanter Pumprate (Fließgeschwindigkeit) , nämlich 120 ml/min, durch eine Messingkapillare mit einem Innendurchmesser von 1,5 mm und einer Länge von ca. 4 m gepumpt; dabei wurde der Druck vor und nach der Kapillare gemessen. Nach dem Hagen-Poiseuilleschen Gesetz hängt - bei konstanter Pumprate und gleichen Kapillarabmessungen - die Druckdifferenz nur von der Viskosität der Flüssigkeit ab. Da die Viskosität in dem für Direkt -Methanol -Brennstoffzellen relevanten Konzentrationsbereich (nahezu) linear mit der Methanolkonzentration ansteigt, besteht ein eindeutiger Zusammenhang zwischen Druckdifferenz und Konzentration. Dieser eindeutige Zusammenhang wurde bei den durchgeführten Ver- suchen auch festgestellt. Wird deshalb mit Lösungen bekannter Konzentration eine Eichkurve erstellt, dann kann die (unbekannte) Konzentration des Methanols im Anodenkreislauf mittels der gemessenen Druckdifferenz über die Kapillare ermittelt werden.In experiments to carry out the method according to the invention, methanol / water mixtures of different concentrations at 25 ° C with constant pumping rate (flow rate), namely 120 ml / min, through a brass capillary with an inner diameter of 1.5 mm and a length of approx 4 m pumped; the pressure before and after the capillary was measured. According to Hagen-Poiseuille's law - with a constant pumping rate and the same capillary dimensions - the pressure difference only depends on the viscosity of the liquid. Since the viscosity in the concentration range relevant for direct methanol fuel cells increases (almost) linearly with the methanol concentration, there is a clear connection between pressure difference and concentration. This clear connection was also found in the tests carried out. If a calibration curve is therefore created with solutions of known concentration, the (unknown) concentration of methanol in the anode circuit can be determined by means of the measured pressure difference across the capillary.
Für die Anwendung der Vorrichtung bieten sich zwei Möglichkeiten an:There are two options for using the device:
(1) Die Engstelle wird direkt in den Anodenkreislauf eingebaut und das Alkohol/Wasser-Gemisch mittels der ohnehin vorhandenen Umwälzpumpe, die den Wert dV/dt (Fließgeschwindigkeit) liefert, durch die Engstelle gedrückt. Bei dieser Ausführungsform muss allerdings das gesamte Gemisch durch die Engstelle gefördert werden, was einen erhöhten Energieaufwand bedeuten könnte. Außerdem hat beispielsweise beim Betrieb von DMFC-Stacks das Methanol/ Wasser-Gemisch eine Temperatur im Bereich von 80 bis 110°C, was sich ungünstig auf die Viskositätsunterschiede auswirken könnte.(1) The constriction is built directly into the anode circuit and the alcohol / water mixture is pressed through the constriction by means of the circulating pump, which already has the value dV / dt (flow rate). In this embodiment, however, the entire mixture has to be conveyed through the constriction, which could mean an increased expenditure of energy. In addition, for example when operating DMFC stacks, the methanol / water mixture has a temperature in the range from 80 to 110 ° C., which could have an unfavorable effect on the viscosity differences.
(2) Die Engstelle wird in einen Bypass zum Anodenkreislauf eingebaut. Dies hat den Vorteil, dass nur eine kleine(2) The bottleneck is built into a bypass to the anode circuit. This has the advantage that only a small one
Menge des Alkohol/Wasser-Gemisches durch die Engstelle gedrückt werden muss. Diese geringe Menge, die eine ge- ringere Wärmekapazität besitzt, kann im Bedarfsfall auch auf niedere Temperaturen thermostatisiert werden. Bei dieser Ausführungsform muss allerdings eine zusätzliche Messung der Fließgeschwindigkeit (dV/dt) der Flüssigkeit im Bypass erfolgen. Amount of alcohol / water mixture must be pressed through the narrow point. This small amount, which is a has lower heat capacity, can be thermostatted to low temperatures if necessary. In this embodiment, however, an additional measurement of the flow rate (dV / dt) of the liquid in the bypass must be carried out.
Claims
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19945931 | 1999-09-24 | ||
| DE19945931A DE19945931A1 (en) | 1999-09-24 | 1999-09-24 | Determination of the alcohol concentration in the electrolyte of fuel cells |
| PCT/DE2000/003168 WO2001024297A1 (en) | 1999-09-24 | 2000-09-12 | Determination of alcohol concentration in an electrolyte of fuel cells |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| EP1218955A1 true EP1218955A1 (en) | 2002-07-03 |
Family
ID=7923249
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| EP00967565A Withdrawn EP1218955A1 (en) | 1999-09-24 | 2000-09-12 | Determination of alcohol concentration in an electrolyte of fuel cells |
Country Status (6)
| Country | Link |
|---|---|
| US (1) | US6536262B2 (en) |
| EP (1) | EP1218955A1 (en) |
| JP (1) | JP2003510787A (en) |
| CA (1) | CA2385640A1 (en) |
| DE (1) | DE19945931A1 (en) |
| WO (1) | WO2001024297A1 (en) |
Families Citing this family (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB0008950D0 (en) * | 2000-04-12 | 2000-05-31 | Univ Cambridge | Apparatus and method for assay of a fluid analyte |
| JP3655569B2 (en) | 2001-09-06 | 2005-06-02 | 大陽日酸株式会社 | Gas component concentration measuring method and apparatus |
| EP1298427A1 (en) * | 2001-09-27 | 2003-04-02 | Abb Research Ltd. | Method for determining the concentration of a fluid solution and its use |
| JP4204526B2 (en) * | 2004-07-30 | 2009-01-07 | 三洋電機株式会社 | Fuel cell system |
| KR100601977B1 (en) * | 2004-12-09 | 2006-07-18 | 삼성에스디아이 주식회사 | Methanol concentration measuring device |
| KR100670489B1 (en) | 2005-09-27 | 2007-01-16 | 삼성에스디아이 주식회사 | Fuel cell system |
| JP4906583B2 (en) * | 2007-05-15 | 2012-03-28 | 株式会社日本自動車部品総合研究所 | Fuel property detection device |
| US9134204B2 (en) * | 2011-08-08 | 2015-09-15 | Kam Controls, Inc. | Apparatus and method for maintaining consistent fluid velocity and homogeneity in a pipeline |
| AU2015373491A1 (en) * | 2014-12-31 | 2017-04-20 | Société des Produits Nestlé S.A. | Method of continuously measuring the shear viscosity of a product paste |
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| DE1902481A1 (en) * | 1969-01-18 | 1970-08-13 | Varta Ag | Alcohol concn control in fuel cell - elements |
| JPS58221148A (en) * | 1982-06-16 | 1983-12-22 | Yaskawa Electric Mfg Co Ltd | Sludge concentration meter |
| JPS60114557A (en) | 1983-11-24 | 1985-06-21 | Mitsubishi Electric Corp | Manufacture of copper alloy plate and bar |
| WO1991014167A1 (en) * | 1990-03-16 | 1991-09-19 | Slurry Systems Pty. Limited | Continuous on-line measurement of fluid or slurry rheology |
| RU1789909C (en) * | 1990-10-15 | 1993-01-23 | Самарское специальное конструкторское бюро Научно-производственного объединения "Нефтехимавтоматика" | Method of measurement of viscosity of liquid in pipe-line |
| US5974867A (en) * | 1997-06-13 | 1999-11-02 | University Of Washington | Method for determining concentration of a laminar sample stream |
| DE19850720C2 (en) * | 1998-11-03 | 2001-06-21 | Forschungszentrum Juelich Gmbh | Method for controlling the fuel concentration in an alcohol or ether fuel mixture containing fuel and water in a fuel cell and fuel cell system |
| DE19904506C2 (en) * | 1999-02-04 | 2002-10-24 | Forschungszentrum Juelich Gmbh | Method and device for the quantitative determination of alcohols |
| DE19938790A1 (en) | 1999-08-16 | 2001-02-22 | Siemens Ag | Determination of the fuel concentration in the electrolyte of fuel cells operated with liquid fuel |
| DE19948908C2 (en) * | 1999-10-11 | 2001-10-04 | Siemens Ag | Method for determining the alcohol concentration in fuel cells and a fuel cell system suitable for carrying it out |
-
1999
- 1999-09-24 DE DE19945931A patent/DE19945931A1/en not_active Ceased
-
2000
- 2000-09-12 JP JP2001527386A patent/JP2003510787A/en not_active Withdrawn
- 2000-09-12 EP EP00967565A patent/EP1218955A1/en not_active Withdrawn
- 2000-09-12 CA CA002385640A patent/CA2385640A1/en not_active Abandoned
- 2000-09-12 WO PCT/DE2000/003168 patent/WO2001024297A1/en not_active Application Discontinuation
-
2002
- 2002-03-25 US US10/105,850 patent/US6536262B2/en not_active Expired - Fee Related
Non-Patent Citations (1)
| Title |
|---|
| See references of WO0124297A1 * |
Also Published As
| Publication number | Publication date |
|---|---|
| WO2001024297A1 (en) | 2001-04-05 |
| DE19945931A1 (en) | 2001-05-03 |
| CA2385640A1 (en) | 2001-04-05 |
| US6536262B2 (en) | 2003-03-25 |
| JP2003510787A (en) | 2003-03-18 |
| US20020121129A1 (en) | 2002-09-05 |
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