US20060216155A1 - Ejector - Google Patents
Ejector Download PDFInfo
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- US20060216155A1 US20060216155A1 US11/391,169 US39116906A US2006216155A1 US 20060216155 A1 US20060216155 A1 US 20060216155A1 US 39116906 A US39116906 A US 39116906A US 2006216155 A1 US2006216155 A1 US 2006216155A1
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- United States
- Prior art keywords
- auxiliary
- stream
- gas
- ejector
- needle
- 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.)
- Abandoned
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Classifications
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- 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
- H01M8/04201—Reactant storage and supply, e.g. means for feeding, pipes
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- 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
- H01M8/04089—Arrangements for control of reactant parameters, e.g. pressure or concentration of gaseous reactants
- H01M8/04097—Arrangements for control of reactant parameters, e.g. pressure or concentration of gaseous reactants with recycling of the reactants
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
- B01F25/00—Flow mixers; Mixers for falling materials, e.g. solid particles
- B01F25/30—Injector mixers
- B01F25/31—Injector mixers in conduits or tubes through which the main component flows
- B01F25/312—Injector mixers in conduits or tubes through which the main component flows with Venturi elements; Details thereof
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
- B01F25/00—Flow mixers; Mixers for falling materials, e.g. solid particles
- B01F25/30—Injector mixers
- B01F25/31—Injector mixers in conduits or tubes through which the main component flows
- B01F25/312—Injector mixers in conduits or tubes through which the main component flows with Venturi elements; Details thereof
- B01F25/3124—Injector mixers in conduits or tubes through which the main component flows with Venturi elements; Details thereof characterised by the place of introduction of the main flow
- B01F25/31242—Injector mixers in conduits or tubes through which the main component flows with Venturi elements; Details thereof characterised by the place of introduction of the main flow the main flow being injected in the central area of the venturi, creating an aspiration in the circumferential part of the conduit
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
- B01F2101/00—Mixing characterised by the nature of the mixed materials or by the application field
- B01F2101/59—Mixing reaction ingredients for fuel cells
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
- B01F25/00—Flow mixers; Mixers for falling materials, e.g. solid particles
- B01F25/30—Injector mixers
- B01F25/31—Injector mixers in conduits or tubes through which the main component flows
- B01F25/312—Injector mixers in conduits or tubes through which the main component flows with Venturi elements; Details thereof
- B01F25/3125—Injector mixers in conduits or tubes through which the main component flows with Venturi elements; Details thereof characteristics of the Venturi parts
- B01F25/31251—Throats
- B01F25/312511—Adjustable Venturi throat
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- 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
- H01M8/24—Grouping of fuel cells, e.g. stacking of fuel cells
- H01M8/249—Grouping of fuel cells, e.g. stacking of fuel cells comprising two or more groupings of fuel cells, e.g. modular assemblies
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- 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 present invention relates to an ejector which has a configuration in which an auxiliary-stream gas is made to join a drive-stream gas for discharge the drive-stream gas and the auxiliary-stream gas therefrom.
- the ejector is such as to have a construction in which circulating hydrogen is drawn in for re-supply by making use of negative pressure produced by injecting a high-pressure fluid from a jet nozzle.
- the circulating capability is limited by the diameter of the jet nozzle, and hence, there occurs a case where the ejector is not suitable for a fuel cell system having a large flow rate range such as one for a motor vehicle.
- JP-A-8-338398 proposes a technique in which the opening area of an injection nozzle is adjusted by axially moving a cylindrical adjusting rod (a needle).
- a needle set in a nozzle is caused to deviate minutely from an axial direction thereof.
- a configuration such as seen in the aforementioned technique is adopted for the ejector like this in which an auxiliary-stream gas is caused to simply hit the needle, there is caused a problem in the drawing force and drawing amount of the auxiliary stream.
- FIGS. 4 and 5 are drawings which illustrate a main part of a conventional ejector to describe the problem inherent therein.
- a distal end portion of a needle 33 is displaced in a direction in which the distal end portion moves away from an auxiliary-stream gas (namely, in a direction which follows an arrow A in FIG. 4 )
- an opening area of a location of a distal end portion of a nozzle 32 which lies near the auxiliary-stream gas namely, a lower region of the distal end portion of the nozzle 32
- a drawing force exerted on the auxiliary-stream gas by a driven steam of gas is increased, whereby the flow rate of the auxiliary-stream gas is increased excessively (refer to FIG. 4 ).
- an object of the invention is to provide an ejector which can control the flow rate and flow velocity of the auxiliary-stream gas with good accuracy.
- an ejector comprising:
- a nozzle portion (for example, a nozzle 32 in an embodiment which will be described later on) having openings provided at a distal end and a proximal end thereof, respectively, for injecting drive-stream gas;
- a diffuser portion (for example, a diffuser 31 in the embodiment which will be described later on) provided on a distal end side of the nozzle portion for drawing in auxiliary gas by negative pressure which is generated in the drive-stream gas by injection from the nozzle portion so as to join the auxiliary-stream gas together with the drive-stream and discharge the drive-stream gas and the auxiliary gas;
- a needle for example, a needle 33 in the embodiment which will be described later on
- a needle 33 for example, a needle 33 in the embodiment which will be described later on
- a drive unit for example, a solenoid 11 in the embodiment for moving the needle axially;
- an auxiliary stream introducing portion (for example, an auxiliary-stream gas introducing portion 13 in the embodiment) comprising at least two openings for introducing the auxiliary-stream gas into the diffuser portion therefrom.
- the auxiliary-stream gas is introduced from at least two openings in the auxiliary stream introducing portion, the auxiliary-stream gas is allowed to be introduced from a plurality of directions relative to the needle, and as a result, the pressure exerted on the needle from the auxiliary-stream gas can be dispersed relative to the axial direction of the needle. Consequently, deviations in drawing force and drawing amount triggered by the deviation of the needle from the axial direction thereof can be suppressed, whereby since the opening area and opening region of the nozzle portion can be maintained in originally designed states, the drawing force and drawing amount of the auxiliary-stream gas can be controlled with good accuracy without being affected by the deviation of the needle from the axial direction thereof.
- the ejector further comprising a buffer chamber provided on an upstream side of the auxiliary stream introducing portion,
- auxiliary-stream gas is adopted to be introduced into the plurality of openings from the buffer chamber.
- auxiliary-stream gas can be distributed to each of the openings via the buffer chamber without having to have a configuration in which piping is individually connected to each auxiliary stream introducing portion, auxiliary-stream gas can easily be supplied to the diffuser portion from multiple directions.
- the ejector is used on a fuel cell system.
- the drawing force and drawing amount of auxiliary-stream gas can be controlled with good accuracy regardless of the shaft position of the needle, an easy and fine control of the flow of fuel cell system gas can be implemented, whereby the power generation stability of the fuel cell can be enhanced.
- the openings of the auxiliary stream introducing portion are arranged along with a circumferential direction of the diffuser portion.
- the openings of the auxiliary stream introducing portion are arranged in point symmetry manner relative to a central axis of the needle.
- the drawing force and drawing amount of the auxiliary-stream gas can be controlled with good accuracy.
- the auxiliary-stream gas can easily be supplied to the diffuser portion from multiple directions.
- the power generation stability of the fuel cell can be enhanced.
- FIG. 1 is a drawing which illustrates the configuration of a fuel cell system which includes a variable flow rate ejector according to an embodiment of the invention
- FIG. 2 is a side sectional view of the variable flow rate ejector according to the embodiment of the invention.
- FIG. 3 is an explanatory drawing which illustrates the flow of auxiliary-stream gas of the variable flow rate ejector according to the embodiment of the invention
- FIG. 4 is a drawing depicting a main part of a conventional ejector which illustrates a problem inherent therein;
- FIG. 5 is a drawing depicting the main part of the conventional ejector which illustrates a problem inherent therein.
- FIG. 1 is a drawing which shows the configuration of a fuel cell system 20 including a variable flow rate ejector 10 according an embodiment of the invention
- FIG. 2 is a side sectional view of the variable flow rate ejector 10 according to the embodiment of the invention.
- the variable flow rate ejector 10 according to the embodiment of the invention is provided in the fuel cell system 20 which is installed on a vehicle such as an electric vehicle, and this fuel cell system 20 is made up of the variable flow rate ejector 10 , fuel cells 21 , an oxidant supply unit 24 , a heat exchanger 25 and a water separator 26 .
- the fuel cell 21 is made up of a stack which includes a plurality of stacked cells, each formed by holding a solid polymer electrolyte membrane, which is, for example, a solid polymer ion exchange membrane by an anode and a cathode from both sides thereof and includes a fuel electrode to which, for example, hydrogen is supplied as a fuel; and an air electrode to which, for example, air containing oxygen is supplied as an oxidant.
- a solid polymer electrolyte membrane which is, for example, a solid polymer ion exchange membrane by an anode and a cathode from both sides thereof and includes a fuel electrode to which, for example, hydrogen is supplied as a fuel; and an air electrode to which, for example, air containing oxygen is supplied as an oxidant.
- An air supply port 21 a into which air is supplied from the oxidant supply unit 24 and an air discharge port 21 b having provided therein an air discharge valve 28 for discharging air or the like in the air electrode to the outside are provided on the air electrode.
- a fuel supply port 21 c to which hydrogen is supplied and a fuel discharge port 21 d for discharging hydrogen or the like in the fuel electrode to the outside are provided on the fuel electrode.
- the oxidant supply unit 24 is made up of, for example, a compressor and is controlled in response to a load applied to the fuel cell 21 , an input signal from an accelerator pedal (not shown) and the like, so as to supply air to the air electrode of the fuel cell 21 via the heat exchanger 25 .
- the heat exchanger 25 cools air sent from the oxidant supply unit 24 down to a predetermined temperature for supply to the fuel cell 21 .
- Hydrogen which functions as fuel, is supplied from the fuel supply port 21 c to the fuel electrode of the fuel cell 21 via the variable flow rate ejector 10 . Furthermore, a discharged fuel which is discharged from the fuel discharge portion 21 d of the fuel cell 21 is introduced into the variable flow rate ejector 10 through a check valve 29 after water is removed therefrom at the water separator 26 , and as will be described later on, fuel and the discharged fuel discharged from the fuel cell 21 are made to join or mix with each other for supply to the fuel cell 21 . Note that water separated from the discharged fuel at the water separator 26 is discharged to the outside by opening a drain valve 30 .
- variable flow rate ejector 10 is such as to make a discharged fuel circulated from the fuel cell 21 join a stream of fuel gas supplied from the fuel supply unit 22 by making use of the stream of fuel gas so supplied and to control the flow rate of fuels supplied to the fuel cell 21 based on an air pressure Pair on the air electrode side of the fuel cell 21 which is detected by a pressure sensor 7 and a fuel pressure Pfuel on the fuel electrode side of the fuel cell 21 which is detected by a pressure sensor 6 when receiving a control instruction from an ECU 5 and is configured to include, as shown in FIG. 2 , a diffuser 31 , a nozzle 32 and a needle 33 .
- a fluid passageway 43 is formed in the diffuser 31 in such a manner as to penetrate axially the diffuser 31 on a downstream side thereof.
- the fluid passageway 43 has a throat portion 44 where an inside diameter thereof becomes minimum at a position along the length thereof, and a throttle portion 45 is provided upstream of the throat portion 44 which has an inner circumferential surface which diametrically contracts gradually and continuously as it proceeds downstream, and a diametrically expanding portion 46 is provided downstream of the throat portion 44 which has an inner circumferential surface which diametrically expands gradually and continuously as it proceeds downstream.
- the nozzle 32 is provided in an interior of the diffuser 31 in such a manner as to protrude coaxially with the diffuser 31 towards an upstream side of the fluid passageway 43 .
- a fluid passageway 51 is formed in an interior of the nozzle 32 in such a manner as to extend along an axial direction of the nozzle 32 .
- An inner circumferential surface 32 A which constitutes a wall surface of the fluid passageway 51 , is formed at a distal end portion of the nozzle 32 in such a manner as to diametrically contract gradually and continuously towards a distal end side thereof (a downstream side of the fluid passageway 51 ).
- a downstream end of the fluid passageway 51 continues to an opening 52 which opens at a distal end face 32 b of the nozzle 32 , and an upstream end of the fluid passageway 51 is blocked up by a diaphragm (not shown).
- a fuel supply pipe (not shown) is connected to the fluid passageway 51 for introducing therein to fuel supplied from the fuel supply unit 22 .
- the needle 33 is inserted into the interior of the nozzle 32 coaxially with the nozzle 32 , and the needle 33 is held by a needle holding guide (not shown) in such a manner as to slide in an axial direction which is coaxial with the nozzle 32 .
- a needle holding guide (not shown)
- an outer circumferential surface of the needle 33 is formed at a distal end portion of the needle 33 in such a manner as to diametrically contract gradually and continuously as it extends towards a distal end side thereof. Namely, when the needle 33 slides in the axial direction in the interior of the nozzle 32 , a protruding amount of the distal end portion of the needle 33 which protrudes from the opening 52 of the nozzle 32 is changed.
- an opening area of a gap between the inner circumferential surface of the nozzle 32 and the outer circumferential surface of the needle 33 is changed, whereby the flow rate of fuel that is injected into an auxiliary stream chamber 48 from the opening 52 of the nozzle 32 can be adjusted.
- the needle holding guide which holds the needle 33 in such a manner as to slide relative to the axial direction, is formed into, for example, an annular disc shape having an appropriate through hole through which fluid can pass, and the needle 33 is inserted through a needle insertion hole which penetrates the annular disc in the axial direction.
- the needle 33 is connected electrically and mechanically to a solenoid 11 , so that the needle 33 is configured to be moved back and forth in the axial direction in response to ON/OFF operations of the solenoid 11 .
- an auxiliary-stream gas introducing portion 13 having a plurality of auxiliary-stream gas introducing holes 12 is formed in the auxiliary stream chamber 48 at a location which faces the outer circumferential surface of the nozzle 32 .
- This auxiliary-stream gas introducing portion 13 is connected to an auxiliary stream introducing pipe 49 , which communicates with a fuel off-gas discharge path, via a buffer chamber 14 which is formed on an outer circumferential side of the auxiliary-stream gas introducing portion 13 .
- pluralities of the auxiliary stream gas introducing holes 12 are arranged along with a circumferential direction of the diffuser 31 .
- FIG. 3 is an explanatory drawing which illustrates the flow of an auxiliary-stream gas in the variable flow rate ejector according the embodiment of the invention.
- variable flow rate ejector 10 a discharged fuel gas from the fuel cell 21 is supplied therein to from the auxiliary stream introducing pipe 49 through the plurality of auxiliary-stream gas introducing holes 12 possessed by the auxiliary-stream gas introducing portion 13 via the buffer chamber 14 .
- a fuel is supplied into the fluid passageway 51 in the interior of the nozzle 32 from the fuel supply pipe (not shown). Then, the fuel so supplied is injected from the opening 52 of the nozzle 32 , that is, the gap between the nozzle 32 and the needle 33 towards the fluid passageway 43 of the diffuser 31 .
- the auxiliary-stream gas in this case, the discharged fuel gas
- the auxiliary-stream gas is introduced individually from the plurality of auxiliary-stream gas introducing holes 12 .
- the auxiliary-stream gas is introduced from a plurality of directions relative to the needle 33 .
- a pressure that the needle 33 receives from the auxiliary-stream gas can be dispersed relative to the axial direction.
- the auxiliary-stream gas can be distributed individually to the plurality of auxiliary-stream gas introducing holes 12 via the buffer chamber 14 , the auxiliary-stream gas can easily be supplied to the diffuser 31 from multiple directions.
- the auxiliary-stream gas introducing holes 12 are disposed in point symmetry relative to a central axis of the needle 33 , whereby the auxiliary-stream gas is dispersed, so as to hit the needle 33 not only from the multiple direction but also in substantially the same amount, thereby making it possible to obtain an advantage where the deviation in position of the needle 33 can be suppressed.
- the advantage can be achieved by arranging the auxiliary-stream gas introducing holes 12 along with the circumferential direction of the diffuser 31 , as described above.
- the ejector 10 by applying the ejector 10 to the fuel cell system, an easy and fine control of the stream of fuel cell system gas can be implemented, whereby the power generation stability of the fuel cell can be enhanced. Note that a space for the water separator 26 or the like is secured upstream of the ejector 10 , even in the event that the buffer chamber 14 is configured to be provided in the ejector 10 , an effect resulting from a reduction in sucking amount can be suppressed.
- the control of drawing force and drawing amount of auxiliary-stream gas can be implemented with good accuracy.
- the contents of the invention are, of course, not limited to the embodiment.
- the ejector is described as being applied to the fuel cell system, the ejector can be applied to other systems.
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- Chemical Kinetics & Catalysis (AREA)
- Life Sciences & Earth Sciences (AREA)
- Sustainable Development (AREA)
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
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- Jet Pumps And Other Pumps (AREA)
Abstract
An ejector having a nozzle portion having openings provided at a distal end and a proximal end thereof, respectively, for injecting drive-stream gas, a diffuser portion provided on a distal end side of the nozzle portion for drawing in auxiliary gas by negative pressure which is generated in the drive-stream gas by injection from the nozzle portion so as to join the auxiliary-stream gas together with the drive-stream and discharge the drive-stream gas and the auxiliary gas, a needle slidably inserted into an interior of the nozzle portion in an axial direction of the nozzle portion for adjusting an opening area of the nozzle portion in accordance with an inserted position thereof, a drive unit for moving the needle axially and an auxiliary stream introducing portion comprising at least two openings for introducing the auxiliary-stream gas into the diffuser portion therefrom.
Description
- The present invention claims foreign priority to Japanese patent application No. P.2005-092325, filed on Mar. 28, 2005, the contents of which is incorporated herein by reference.
- 1. Field of the Invention
- The present invention relates to an ejector which has a configuration in which an auxiliary-stream gas is made to join a drive-stream gas for discharge the drive-stream gas and the auxiliary-stream gas therefrom.
- 2. Description of the Background Art
- There has been proposed a technique in which an ejector is used as a hydrogen circulating pump in a fuel cell system. The ejector is such as to have a construction in which circulating hydrogen is drawn in for re-supply by making use of negative pressure produced by injecting a high-pressure fluid from a jet nozzle.
- When the ejector so constructed is used, the circulating capability is limited by the diameter of the jet nozzle, and hence, there occurs a case where the ejector is not suitable for a fuel cell system having a large flow rate range such as one for a motor vehicle.
- On the contrary, Japanese Patent Unexamined Publication No. JP-A-8-338398 proposes a technique in which the opening area of an injection nozzle is adjusted by axially moving a cylindrical adjusting rod (a needle).
- Incidentally, depending on the production accuracy of constituent components of an ejector such as a needle and its guide member or an actuator for moving the needle, a needle set in a nozzle is caused to deviate minutely from an axial direction thereof. In the event that a configuration such as seen in the aforementioned technique is adopted for the ejector like this in which an auxiliary-stream gas is caused to simply hit the needle, there is caused a problem in the drawing force and drawing amount of the auxiliary stream.
- The problem will be described using
FIGS. 4, 5 .FIGS. 4 and 5 are drawings which illustrate a main part of a conventional ejector to describe the problem inherent therein. Firstly, in the event that a distal end portion of aneedle 33 is displaced in a direction in which the distal end portion moves away from an auxiliary-stream gas (namely, in a direction which follows an arrow A inFIG. 4 ), an opening area of a location of a distal end portion of anozzle 32 which lies near the auxiliary-stream gas (namely, a lower region of the distal end portion of the nozzle 32) is increased. As a result, a drawing force exerted on the auxiliary-stream gas by a driven steam of gas is increased, whereby the flow rate of the auxiliary-stream gas is increased excessively (refer to FIG. 4). - In contrast, in the event that the distal end portion of the
needle 33 is displaced in a direction in which the distal end portion approaches the auxiliary-stream gas (namely, in an opposite direction to an arrow A inFIG. 5 ) due to the pressure of the auxiliary-stream gas, an opening area of a location of the distal end portion of the nozzle which lies away from the auxiliary-stream gas (namely, an upper region of the distal end portion of the nozzle 32) is increased. As a result, the drawing force exerted on the auxiliary-stream gas by the drive-stream gas is decreased, whereby the flow rate of the auxiliary-stream gas is decreased excessively (refer toFIG. 5 ). - Thus, there exists a problem where an accurate control of the drawing force and drawing amount of the auxiliary-stream gas becomes difficult to be implemented. In particular, in a case where an ejector is installed in a fuel cell system in which an unreacted off-gas is circulated, the unreacted off-gas constitutes an auxiliary stream, and since the flow rate and flow velocity of the auxiliary stream can affect power generating conditions, controlling the flow rate and flow velocity of the auxiliary stream becomes crucial to secure a desired power generation performance, as well. While it is considered as a means for attaining this to configure the needle to follow precisely the axis thereof in a perfect fashion when it slides, there is caused a problem where since a severe accuracy which is required for production deteriorates the productivity, the attempt is unrealistic.
- Consequently, an object of the invention is to provide an ejector which can control the flow rate and flow velocity of the auxiliary-stream gas with good accuracy.
- According to a first aspect of the invention, there is provided an ejector comprising:
- a nozzle portion (for example, a
nozzle 32 in an embodiment which will be described later on) having openings provided at a distal end and a proximal end thereof, respectively, for injecting drive-stream gas; - a diffuser portion (for example, a
diffuser 31 in the embodiment which will be described later on) provided on a distal end side of the nozzle portion for drawing in auxiliary gas by negative pressure which is generated in the drive-stream gas by injection from the nozzle portion so as to join the auxiliary-stream gas together with the drive-stream and discharge the drive-stream gas and the auxiliary gas; - a needle (for example, a
needle 33 in the embodiment which will be described later on) slidably inserted into an interior of the nozzle portion in an axial direction of the nozzle portion for adjusting an opening area of the nozzle portion in accordance with an inserted position thereof; - a drive unit (for example, a
solenoid 11 in the embodiment) for moving the needle axially; and - an auxiliary stream introducing portion (for example, an auxiliary-stream
gas introducing portion 13 in the embodiment) comprising at least two openings for introducing the auxiliary-stream gas into the diffuser portion therefrom. - According to the first aspect of the invention, since the auxiliary-stream gas is introduced from at least two openings in the auxiliary stream introducing portion, the auxiliary-stream gas is allowed to be introduced from a plurality of directions relative to the needle, and as a result, the pressure exerted on the needle from the auxiliary-stream gas can be dispersed relative to the axial direction of the needle. Consequently, deviations in drawing force and drawing amount triggered by the deviation of the needle from the axial direction thereof can be suppressed, whereby since the opening area and opening region of the nozzle portion can be maintained in originally designed states, the drawing force and drawing amount of the auxiliary-stream gas can be controlled with good accuracy without being affected by the deviation of the needle from the axial direction thereof.
- According to a second aspect of the invention, as set forth in the first aspect of the present invention, it is preferable that the ejector further comprising a buffer chamber provided on an upstream side of the auxiliary stream introducing portion,
- wherein the auxiliary-stream gas is adopted to be introduced into the plurality of openings from the buffer chamber.
- According to the structure, since an auxiliary-stream gas can be distributed to each of the openings via the buffer chamber without having to have a configuration in which piping is individually connected to each auxiliary stream introducing portion, auxiliary-stream gas can easily be supplied to the diffuser portion from multiple directions.
- According to a third aspect of the invention, as set forth in the first aspect of the present invention, it is preferable that the ejector is used on a fuel cell system.
- According to the structure, since the drawing force and drawing amount of auxiliary-stream gas can be controlled with good accuracy regardless of the shaft position of the needle, an easy and fine control of the flow of fuel cell system gas can be implemented, whereby the power generation stability of the fuel cell can be enhanced.
- According to a fourth aspect of the present invention, as set forth in the first aspect of the present invention, it is preferable that the openings of the auxiliary stream introducing portion are arranged along with a circumferential direction of the diffuser portion.
- According to a fifth aspect of the present invention, as set forth in the first aspect of the present invention, it is preferable that the openings of the auxiliary stream introducing portion are arranged in point symmetry manner relative to a central axis of the needle.
- According to the first aspect of the invention, since the opening area and opening region of the nozzle portion can be maintained in the originally designed states, the drawing force and drawing amount of the auxiliary-stream gas can be controlled with good accuracy.
- According to the second aspect of the invention, the auxiliary-stream gas can easily be supplied to the diffuser portion from multiple directions.
- According to the third aspect of the invention, the power generation stability of the fuel cell can be enhanced.
-
FIG. 1 is a drawing which illustrates the configuration of a fuel cell system which includes a variable flow rate ejector according to an embodiment of the invention; -
FIG. 2 is a side sectional view of the variable flow rate ejector according to the embodiment of the invention; -
FIG. 3 is an explanatory drawing which illustrates the flow of auxiliary-stream gas of the variable flow rate ejector according to the embodiment of the invention; -
FIG. 4 is a drawing depicting a main part of a conventional ejector which illustrates a problem inherent therein; and -
FIG. 5 is a drawing depicting the main part of the conventional ejector which illustrates a problem inherent therein. - Hereinafter, a variable flow rate ejector according to an embodiment of the invention will be described by reference to the accompanying drawings.
FIG. 1 is a drawing which shows the configuration of afuel cell system 20 including a variableflow rate ejector 10 according an embodiment of the invention, andFIG. 2 is a side sectional view of the variableflow rate ejector 10 according to the embodiment of the invention. The variableflow rate ejector 10 according to the embodiment of the invention is provided in thefuel cell system 20 which is installed on a vehicle such as an electric vehicle, and thisfuel cell system 20 is made up of the variableflow rate ejector 10,fuel cells 21, anoxidant supply unit 24, aheat exchanger 25 and awater separator 26. - The
fuel cell 21 is made up of a stack which includes a plurality of stacked cells, each formed by holding a solid polymer electrolyte membrane, which is, for example, a solid polymer ion exchange membrane by an anode and a cathode from both sides thereof and includes a fuel electrode to which, for example, hydrogen is supplied as a fuel; and an air electrode to which, for example, air containing oxygen is supplied as an oxidant. - An
air supply port 21 a into which air is supplied from theoxidant supply unit 24 and anair discharge port 21 b having provided therein anair discharge valve 28 for discharging air or the like in the air electrode to the outside are provided on the air electrode. On the other hand, afuel supply port 21 c to which hydrogen is supplied and afuel discharge port 21 d for discharging hydrogen or the like in the fuel electrode to the outside are provided on the fuel electrode. - The
oxidant supply unit 24 is made up of, for example, a compressor and is controlled in response to a load applied to thefuel cell 21, an input signal from an accelerator pedal (not shown) and the like, so as to supply air to the air electrode of thefuel cell 21 via theheat exchanger 25. Theheat exchanger 25 cools air sent from theoxidant supply unit 24 down to a predetermined temperature for supply to thefuel cell 21. - Hydrogen, which functions as fuel, is supplied from the
fuel supply port 21 c to the fuel electrode of thefuel cell 21 via the variableflow rate ejector 10. Furthermore, a discharged fuel which is discharged from thefuel discharge portion 21 d of thefuel cell 21 is introduced into the variableflow rate ejector 10 through acheck valve 29 after water is removed therefrom at thewater separator 26, and as will be described later on, fuel and the discharged fuel discharged from thefuel cell 21 are made to join or mix with each other for supply to thefuel cell 21. Note that water separated from the discharged fuel at thewater separator 26 is discharged to the outside by opening adrain valve 30. - The variable
flow rate ejector 10 according to the embodiment of the invention is such as to make a discharged fuel circulated from thefuel cell 21 join a stream of fuel gas supplied from thefuel supply unit 22 by making use of the stream of fuel gas so supplied and to control the flow rate of fuels supplied to thefuel cell 21 based on an air pressure Pair on the air electrode side of thefuel cell 21 which is detected by apressure sensor 7 and a fuel pressure Pfuel on the fuel electrode side of thefuel cell 21 which is detected by apressure sensor 6 when receiving a control instruction from anECU 5 and is configured to include, as shown inFIG. 2 , adiffuser 31, anozzle 32 and aneedle 33. - A
fluid passageway 43 is formed in thediffuser 31 in such a manner as to penetrate axially thediffuser 31 on a downstream side thereof. Thefluid passageway 43 has athroat portion 44 where an inside diameter thereof becomes minimum at a position along the length thereof, and athrottle portion 45 is provided upstream of thethroat portion 44 which has an inner circumferential surface which diametrically contracts gradually and continuously as it proceeds downstream, and a diametrically expandingportion 46 is provided downstream of thethroat portion 44 which has an inner circumferential surface which diametrically expands gradually and continuously as it proceeds downstream. - The
nozzle 32 is provided in an interior of thediffuser 31 in such a manner as to protrude coaxially with thediffuser 31 towards an upstream side of thefluid passageway 43. - A
fluid passageway 51 is formed in an interior of thenozzle 32 in such a manner as to extend along an axial direction of thenozzle 32. An inner circumferential surface 32A, which constitutes a wall surface of thefluid passageway 51, is formed at a distal end portion of thenozzle 32 in such a manner as to diametrically contract gradually and continuously towards a distal end side thereof (a downstream side of the fluid passageway 51). A downstream end of thefluid passageway 51 continues to anopening 52 which opens at a distal end face 32 b of thenozzle 32, and an upstream end of thefluid passageway 51 is blocked up by a diaphragm (not shown). A fuel supply pipe (not shown) is connected to thefluid passageway 51 for introducing therein to fuel supplied from thefuel supply unit 22. - The
needle 33 is inserted into the interior of thenozzle 32 coaxially with thenozzle 32, and theneedle 33 is held by a needle holding guide (not shown) in such a manner as to slide in an axial direction which is coaxial with thenozzle 32. Here, an outer circumferential surface of theneedle 33 is formed at a distal end portion of theneedle 33 in such a manner as to diametrically contract gradually and continuously as it extends towards a distal end side thereof. Namely, when theneedle 33 slides in the axial direction in the interior of thenozzle 32, a protruding amount of the distal end portion of theneedle 33 which protrudes from theopening 52 of thenozzle 32 is changed. In association with this, an opening area of a gap between the inner circumferential surface of thenozzle 32 and the outer circumferential surface of theneedle 33 is changed, whereby the flow rate of fuel that is injected into anauxiliary stream chamber 48 from theopening 52 of thenozzle 32 can be adjusted. - Note that the needle holding guide, which holds the
needle 33 in such a manner as to slide relative to the axial direction, is formed into, for example, an annular disc shape having an appropriate through hole through which fluid can pass, and theneedle 33 is inserted through a needle insertion hole which penetrates the annular disc in the axial direction. In addition, theneedle 33 is connected electrically and mechanically to asolenoid 11, so that theneedle 33 is configured to be moved back and forth in the axial direction in response to ON/OFF operations of thesolenoid 11. - Additionally, an auxiliary-stream
gas introducing portion 13 having a plurality of auxiliary-streamgas introducing holes 12 is formed in theauxiliary stream chamber 48 at a location which faces the outer circumferential surface of thenozzle 32. This auxiliary-streamgas introducing portion 13 is connected to an auxiliarystream introducing pipe 49, which communicates with a fuel off-gas discharge path, via abuffer chamber 14 which is formed on an outer circumferential side of the auxiliary-streamgas introducing portion 13. For an example, as shown inFIG. 2 , pluralities of the auxiliary streamgas introducing holes 12 are arranged along with a circumferential direction of thediffuser 31. - The
fuel cell system 20 including the variableflow rate ejector 10 according to the embodiment of the invention is configured as has been described heretofore. Next, the operation of the variableflow rate ejector 10 will be described.FIG. 3 is an explanatory drawing which illustrates the flow of an auxiliary-stream gas in the variable flow rate ejector according the embodiment of the invention. - In this variable
flow rate ejector 10, a discharged fuel gas from thefuel cell 21 is supplied therein to from the auxiliarystream introducing pipe 49 through the plurality of auxiliary-streamgas introducing holes 12 possessed by the auxiliary-streamgas introducing portion 13 via thebuffer chamber 14. In addition, a fuel is supplied into thefluid passageway 51 in the interior of thenozzle 32 from the fuel supply pipe (not shown). Then, the fuel so supplied is injected from theopening 52 of thenozzle 32, that is, the gap between thenozzle 32 and theneedle 33 towards thefluid passageway 43 of thediffuser 31. As this occurs, negative pressure is produced in the vicinity of thethroat portion 44 of thediffuser 31 where a high-velocity fuel stream passes, and fuel auxiliary-stream gas within theauxiliary stream chamber 48 is drawn into thefluid passageway 43 by the vacuum so produced, so as to be mixed with the fuel injected from thenozzle 32 for discharge from a downstream end of thediffuser 31, whereby the discharged fuel discharged from thefuel cell 21 is circulated via the variableflow rate ejector 10. - Thus, since the auxiliary-stream gas (in this case, the discharged fuel gas) is introduced individually from the plurality of auxiliary-stream
gas introducing holes 12, the auxiliary-stream gas is introduced from a plurality of directions relative to theneedle 33. As a result, a pressure that theneedle 33 receives from the auxiliary-stream gas can be dispersed relative to the axial direction. Consequently, the deviation in drawing force and drawing amount of auxiliary stream that is triggered by the deviation of theneedle 33 from the axial direction thereof can be suppressed, whereby since the opening area and opening region of thenozzle 32 can be maintained in the originally designed states, even in the event that theneedle 33 is caused to deviate slightly from the axial direction thereof, the drawing force and drawing amount of auxiliary-stream gas can be controlled with good accuracy. - In addition, since the auxiliary-stream gas can be distributed individually to the plurality of auxiliary-stream
gas introducing holes 12 via thebuffer chamber 14, the auxiliary-stream gas can easily be supplied to thediffuser 31 from multiple directions. For an example, the auxiliary-streamgas introducing holes 12 are disposed in point symmetry relative to a central axis of theneedle 33, whereby the auxiliary-stream gas is dispersed, so as to hit theneedle 33 not only from the multiple direction but also in substantially the same amount, thereby making it possible to obtain an advantage where the deviation in position of theneedle 33 can be suppressed. The advantage can be achieved by arranging the auxiliary-streamgas introducing holes 12 along with the circumferential direction of thediffuser 31, as described above. - In addition, by applying the
ejector 10 to the fuel cell system, an easy and fine control of the stream of fuel cell system gas can be implemented, whereby the power generation stability of the fuel cell can be enhanced. Note that a space for thewater separator 26 or the like is secured upstream of theejector 10, even in the event that thebuffer chamber 14 is configured to be provided in theejector 10, an effect resulting from a reduction in sucking amount can be suppressed. - Thus, as has been described heretofore, according to the ejector of the embodiment of the invention, the control of drawing force and drawing amount of auxiliary-stream gas can be implemented with good accuracy.
- Note that the contents of the invention are, of course, not limited to the embodiment. For example, while in the embodiment, the ejector is described as being applied to the fuel cell system, the ejector can be applied to other systems.
- While there has been described in connection with the preferred embodiments of the present invention, it will be obvious to those skilled in the art that various changes and modification may be made therein without departing from the present invention, and it is aimed, therefore, to cover in the appended claim all such changes and modifications as fall within the true spirit and scope.
Claims (5)
1. An ejector comprising:
a nozzle portion having openings provided at a distal end and a proximal end thereof, respectively, for injecting drive-stream gas;
a diffuser portion provided on a distal end side of the nozzle portion for drawing in auxiliary gas by negative pressure which is generated in the drive-stream gas by injection from the nozzle portion so as to join the auxiliary-stream gas together with the drive-stream and discharge the drive-stream gas and the auxiliary gas;
a needle slidably inserted into an interior of the nozzle portion in an axial direction of the nozzle portion for adjusting an opening area of the nozzle portion in accordance with an inserted position thereof;
a drive unit for moving the needle axially; and
an auxiliary stream introducing portion comprising at least two openings for introducing the auxiliary-stream gas into the diffuser portion therefrom.
2. The ejector as set forth in claim 1 , further comprising a buffer chamber provided on an upstream side of the auxiliary stream introducing portion,
wherein the auxiliary-stream gas is adopted to be introduced into the plurality of openings from the buffer chamber.
3. The ejector as set forth in claim 1 , wherein the ejector is used on a fuel cell system.
4. The ejector as set forth in claim 1 , wherein the openings of the auxiliary stream introducing portion are arranged along with a circumferential direction of the diffuser portion.
5. The ejector as set forth in claim 1 , wherein the openings of the auxiliary stream introducing portion are arranged in point symmetry manner relative to a central axis of the needle.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US13/692,505 US20130095397A1 (en) | 2005-03-28 | 2012-12-03 | Ejector |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JPP.2005-092325 | 2005-03-28 | ||
JP2005092325A JP4860165B2 (en) | 2005-03-28 | 2005-03-28 | Ejector |
Related Child Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US13/692,505 Division US20130095397A1 (en) | 2005-03-28 | 2012-12-03 | Ejector |
Publications (1)
Publication Number | Publication Date |
---|---|
US20060216155A1 true US20060216155A1 (en) | 2006-09-28 |
Family
ID=37035365
Family Applications (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US11/391,169 Abandoned US20060216155A1 (en) | 2005-03-28 | 2006-03-27 | Ejector |
US13/692,505 Abandoned US20130095397A1 (en) | 2005-03-28 | 2012-12-03 | Ejector |
Family Applications After (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US13/692,505 Abandoned US20130095397A1 (en) | 2005-03-28 | 2012-12-03 | Ejector |
Country Status (2)
Country | Link |
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US (2) | US20060216155A1 (en) |
JP (1) | JP4860165B2 (en) |
Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2008077445A1 (en) * | 2006-12-22 | 2008-07-03 | Daimler Ag | Device for reducing pressure variations in a system through which gas flows |
US20090155092A1 (en) * | 2007-12-12 | 2009-06-18 | Honda Motor Co., Ltd. | Fuel cell system |
GB2488125A (en) * | 2011-02-16 | 2012-08-22 | Shane Richard Wootton | Injection Apparatus |
CN110132070A (en) * | 2019-04-24 | 2019-08-16 | 中国人民解放军陆军工程大学 | Device and method for detecting projection amount of gun firing pin |
WO2021238899A1 (en) * | 2020-05-29 | 2021-12-02 | 中国石油天然气集团有限公司 | Jet adjusting method for rotary guiding down-hole jam release |
WO2022120401A1 (en) * | 2020-12-11 | 2022-06-16 | Avl List Gmbh | Ejector for a fuel cell system |
Families Citing this family (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP5017925B2 (en) * | 2006-05-19 | 2012-09-05 | 株式会社デンソー | Ejector, evaporator unit and ejector refrigeration cycle |
KR100773345B1 (en) | 2006-10-31 | 2007-11-05 | 주식회사 로템 | Variable type hydrogen recirculaton ejector |
JP5065866B2 (en) * | 2007-11-27 | 2012-11-07 | 本田技研工業株式会社 | Fuel cell system |
KR20150070882A (en) * | 2013-12-17 | 2015-06-25 | 현대자동차주식회사 | Fuel cell system using ejector |
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US1787632A (en) * | 1928-10-20 | 1931-01-06 | William A J Kreager | Burner |
US4434766A (en) * | 1982-05-07 | 1984-03-06 | Toyota Jidosha Kabushiki Kaisha | Air assist device of fuel injection type internal combustion engine |
US6858340B2 (en) * | 2001-02-02 | 2005-02-22 | Honda Giken Kogyo Kabushiki Kaisha | Variable flow-rate ejector and fuel cell system having the same |
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US6706438B2 (en) * | 2000-08-10 | 2004-03-16 | Honda Giken Kogyo Kabushiki Kaisha | Fluid supply device for fuel cell |
JP2002153741A (en) * | 2000-11-21 | 2002-05-28 | Masao Ukisho | Tool for mixing fluid and pump for mixing fluid using the same |
JP4148014B2 (en) * | 2002-07-10 | 2008-09-10 | 株式会社デンソー | Fuel cell system |
-
2005
- 2005-03-28 JP JP2005092325A patent/JP4860165B2/en not_active Expired - Fee Related
-
2006
- 2006-03-27 US US11/391,169 patent/US20060216155A1/en not_active Abandoned
-
2012
- 2012-12-03 US US13/692,505 patent/US20130095397A1/en not_active Abandoned
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US1787632A (en) * | 1928-10-20 | 1931-01-06 | William A J Kreager | Burner |
US4434766A (en) * | 1982-05-07 | 1984-03-06 | Toyota Jidosha Kabushiki Kaisha | Air assist device of fuel injection type internal combustion engine |
US6858340B2 (en) * | 2001-02-02 | 2005-02-22 | Honda Giken Kogyo Kabushiki Kaisha | Variable flow-rate ejector and fuel cell system having the same |
Cited By (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2008077445A1 (en) * | 2006-12-22 | 2008-07-03 | Daimler Ag | Device for reducing pressure variations in a system through which gas flows |
US20090155092A1 (en) * | 2007-12-12 | 2009-06-18 | Honda Motor Co., Ltd. | Fuel cell system |
US8017275B2 (en) * | 2007-12-12 | 2011-09-13 | Honda Motor Co., Ltd. | Fuel cell system |
GB2488125A (en) * | 2011-02-16 | 2012-08-22 | Shane Richard Wootton | Injection Apparatus |
CN110132070A (en) * | 2019-04-24 | 2019-08-16 | 中国人民解放军陆军工程大学 | Device and method for detecting projection amount of gun firing pin |
WO2021238899A1 (en) * | 2020-05-29 | 2021-12-02 | 中国石油天然气集团有限公司 | Jet adjusting method for rotary guiding down-hole jam release |
WO2022120401A1 (en) * | 2020-12-11 | 2022-06-16 | Avl List Gmbh | Ejector for a fuel cell system |
Also Published As
Publication number | Publication date |
---|---|
JP4860165B2 (en) | 2012-01-25 |
US20130095397A1 (en) | 2013-04-18 |
JP2006274854A (en) | 2006-10-12 |
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Legal Events
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AS | Assignment |
Owner name: HONDA MOTOR CO., LTD., JAPAN Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:FUKUMA, KAZUNORI;KAI, MITSURU;INOUE, SATOSHI;AND OTHERS;REEL/FRAME:017747/0410 Effective date: 20060310 |
|
STCB | Information on status: application discontinuation |
Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION |