EP1956228A1 - Vapour recovery system for a vehicle fuel tank - Google Patents
Vapour recovery system for a vehicle fuel tank Download PDFInfo
- Publication number
- EP1956228A1 EP1956228A1 EP07250510A EP07250510A EP1956228A1 EP 1956228 A1 EP1956228 A1 EP 1956228A1 EP 07250510 A EP07250510 A EP 07250510A EP 07250510 A EP07250510 A EP 07250510A EP 1956228 A1 EP1956228 A1 EP 1956228A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- flow path
- recovery system
- inlet
- chamber
- purge
- 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- Withdrawn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
Images
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
- F02M25/00—Engine-pertinent apparatus for adding non-fuel substances or small quantities of secondary fuel to combustion-air, main fuel or fuel-air mixture
- F02M25/08—Engine-pertinent apparatus for adding non-fuel substances or small quantities of secondary fuel to combustion-air, main fuel or fuel-air mixture adding fuel vapours drawn from engine fuel reservoir
- F02M25/0854—Details of the absorption canister
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
- F02M25/00—Engine-pertinent apparatus for adding non-fuel substances or small quantities of secondary fuel to combustion-air, main fuel or fuel-air mixture
- F02M25/08—Engine-pertinent apparatus for adding non-fuel substances or small quantities of secondary fuel to combustion-air, main fuel or fuel-air mixture adding fuel vapours drawn from engine fuel reservoir
- F02M25/089—Layout of the fuel vapour installation
Definitions
- the present invention relates to a vapour recovery system for a vehicle fuel tank comprising a canister containing an adsorbent material, such as carbon, for adsorbing fuel from fuel vapour laden air, and in particular to a vapour recovery system adapted to avoid the need for a purge valve.
- a adsorbent material such as carbon
- the headspace it is necessary to vent the air space in the upper regions of a vehicle fuel tank (known as the headspace) in order to avoid the formation of an air lock as a tank is emptied in use, during refuelling when air is displaced from the headspace as the tank is filled with fuel, and to compensate for pressure changes in the headspace due to evaporation of fuel and subsequent condensation during changes in ambient temperature.
- a typical vapour recovery system comprises an adsorption canister 1 containing an activated carbon filter material 2 having an inlet 3 connected to a tank headspace vent passage, to trap fuel vapour while permitting the passage of air through a vent port 4 to the atmosphere during refuelling of a vehicle.
- adsorbed fuel vapour trapped in the canister is removed by drawing air through the canister 1 through a purge outlet 5 communicating with the air-intake system of the engine such that the desorbed fuel vapour is burnt in the engine.
- the hydrocarbons are desorbed, transferred to engine and burnt.
- the main function of the canister is to adsorb vapours from the fuel system and reduce environmental pollution due to evaporative emissions from gasoline powered engines.
- the vapour recovery system includes a purge valve 6 between the canister purge outlet 5 and the engine.
- the purge valve 6 normally solenoid valve
- the ECU periodically opens the valve to allow hydrocarbons flow to engine.
- the periodical operation is required to limit amount of hydrocarbons delivered to engine. This is critical for engine performance, drivability and vehicle exhaust emissions.
- a partition wall 7 extends within the canister 1 between the vent outlet and purge outlet.
- a mechanical valve (diaphragm or ball-spring valve) is used instead of a solenoid valve to simplify the system and reduce total cost.
- the valve does not provide means of hydrocarbons control during engine operation. Its function is limited to on/off operation. The valve is open all the time during purge and remains closed when engine is off, limiting vapour flow from canister to the engine manifold and reducing evaporative emissions.
- a vapour recovery system for a vehicle fuel tank comprising a canister defining at least one chamber containing an adsorbent material for adsorbing fuel from fuel vapour laden air, the canister having an inlet for communication with the headspace of a vehicle fuel tank, a vent outlet for communication with the atmosphere and a purge outlet for communication with the air intake of the vehicle engine, a first flow path between the inlet and the vent outlet, and a second flow path between the inlet and the purge outlet, wherein the second flow path has a greater flow restriction and/or residence time than the first flow path.
- vapour preferentially flows from the canister inlet to the vent outlet. This eliminates the need for a purge valve associated with the purge outlet.
- the cross sectional area of the first flow path is greater than the cross sectional area of the second flow path.
- the minimum cross sectional area of the first flow path is greater than the minimum cross sectional area of the second flow path.
- the adsorbent material located in the second flow path has a higher restriction to the passage of air than the adsorbent material located in the first flow path.
- the canister may be provided with a further inlet for connection to ambient air for supplying ambient air into said second flow path.
- the canister is divided into first and second chambers, each of said first and second chambers having an inlet end communicating with said canister inlet, said vent outlet being provided at an outlet end of the first chamber and said purge outlet being provided at an outlet end of said second chamber, wherein said first flow path, comprising an adsorption flow path, is defined through said first chamber and said second flow path, comprising a purge flow path, is defined through said second chamber.
- the second chamber may have at least one region of restricted cross sectional area, to provide a flow restriction in the purge flow path, and at least one region of greater cross sectional area, to provide an increased adsorption capacity.
- the second chamber may be provided with a fresh air inlet in a side region thereof.
- the flow restriction of the purge flow path 17 is at least twice that of the adsorption flow path 16, thus vapour laden air from the headspace of the fuel tank preferentially flows through the adsorption flow path 16 from the inlet 13 to the vent outlet 14.
- the purge flow path 17 During rest, because the adsorbent material 20 in the purge flow path 17 adsorbs very little fuel vapour from the tank, it stays considerably clean.
- vapours from first chamber 11 of the canister flow through the adsorbent material in the purge flow path 17 due to the vacuum produced in the engine intake.
- the purge flow path 17 acts as delay line, so engine can warm up before fuel vapour from the canister reaches the engine. This improves engine performance and helps to control exhaust emissions.
- the second chamber 12 defining the purge flow path 17 contains an adsorbent material 20b having a greater resistance to flow than the adsorbent material 20a contained in the first chamber, to further restrict the flow of vapour through the purge flow path.
- the second chamber 12 contains narrower cross section regions 22,23 to provide a flow restriction in the purge flow path, and a wider cross section increased volume region 24 therebetween to provide a greater adsorption capacity. This improves the vapour recovery system performance.
- the large cross section region 24 of the second chamber 12 increases residence time of vapour within the second chamber 24, so peak concentrations of hydrocarbons at the purge outlet 15 are reduced.
- a diluting feature can be implemented to further improve system performance.
- a fresh air inlet 30 is provided in a side region of the second chamber 12 to enable fresh air to be drawn into the purge flow path 17 to further reduce the peak concentrations of hydrocarbons at the purge outlet 15
- the vapour recovery system of the present invention can be used on simple systems, like powered two wheelers in developing countries, to avoid the use of control valves, reduce total vapour recovery system cost and improving system reliability as no movable parts are necessary.
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Supplying Secondary Fuel Or The Like To Fuel, Air Or Fuel-Air Mixtures (AREA)
Abstract
Description
- The present invention relates to a vapour recovery system for a vehicle fuel tank comprising a canister containing an adsorbent material, such as carbon, for adsorbing fuel from fuel vapour laden air, and in particular to a vapour recovery system adapted to avoid the need for a purge valve.
- It is necessary to vent the air space in the upper regions of a vehicle fuel tank (known as the headspace) in order to avoid the formation of an air lock as a tank is emptied in use, during refuelling when air is displaced from the headspace as the tank is filled with fuel, and to compensate for pressure changes in the headspace due to evaporation of fuel and subsequent condensation during changes in ambient temperature.
- However, vehicle emission standards place limits on the evaporative emission of fuel vapour from vehicle fuel tanks and fuel systems. To achieve these emission standards, most modern vehicles are equipped with venting and vapour recovery systems for preventing the release of fuel vapour during refilling, during vehicle operation and while the vehicle is stationary, while at the same time allowing the volume of air and fuel vapour in the tank to vary as the volume of fuel in the tank varies.
- As illustrated in
Figs. 1 and 2 , a typical vapour recovery system comprises an adsorption canister 1 containing an activatedcarbon filter material 2 having aninlet 3 connected to a tank headspace vent passage, to trap fuel vapour while permitting the passage of air through a vent port 4 to the atmosphere during refuelling of a vehicle. Periodically, during operation of the vehicle, adsorbed fuel vapour trapped in the canister is removed by drawing air through the canister 1 through apurge outlet 5 communicating with the air-intake system of the engine such that the desorbed fuel vapour is burnt in the engine. The hydrocarbons are desorbed, transferred to engine and burnt. - The main function of the canister is to adsorb vapours from the fuel system and reduce environmental pollution due to evaporative emissions from gasoline powered engines.
- Typically, the vapour recovery system includes a purge valve 6 between the
canister purge outlet 5 and the engine. On most of the systems the purge valve 6 (normally solenoid valve) is controlled by an ECU. The ECU periodically opens the valve to allow hydrocarbons flow to engine. The periodical operation is required to limit amount of hydrocarbons delivered to engine. This is critical for engine performance, drivability and vehicle exhaust emissions. - In order to avoid the passage of air directly from the vent outlet to the purge outlet, a
partition wall 7 extends within the canister 1 between the vent outlet and purge outlet. - In some applications, such as powered two wheelers, a mechanical valve (diaphragm or ball-spring valve) is used instead of a solenoid valve to simplify the system and reduce total cost. In such solution, the valve does not provide means of hydrocarbons control during engine operation. Its function is limited to on/off operation. The valve is open all the time during purge and remains closed when engine is off, limiting vapour flow from canister to the engine manifold and reducing evaporative emissions.
- However, for low cost applications it is desirable to eliminate the need for a purge valve.
- According to the present invention there is provided a vapour recovery system for a vehicle fuel tank comprising a canister defining at least one chamber containing an adsorbent material for adsorbing fuel from fuel vapour laden air, the canister having an inlet for communication with the headspace of a vehicle fuel tank, a vent outlet for communication with the atmosphere and a purge outlet for communication with the air intake of the vehicle engine, a first flow path between the inlet and the vent outlet, and a second flow path between the inlet and the purge outlet, wherein the second flow path has a greater flow restriction and/or residence time than the first flow path.
- Due to the high restriction and/or greater residence time of the flow path between the canister inlet and the purge outlet, vapour preferentially flows from the canister inlet to the vent outlet. This eliminates the need for a purge valve associated with the purge outlet.
- In one embodiment the cross sectional area of the first flow path is greater than the cross sectional area of the second flow path. Preferably the minimum cross sectional area of the first flow path is greater than the minimum cross sectional area of the second flow path. Alternatively, or additionally, the adsorbent material located in the second flow path has a higher restriction to the passage of air than the adsorbent material located in the first flow path.
- The canister may be provided with a further inlet for connection to ambient air for supplying ambient air into said second flow path.
- Preferably the canister is divided into first and second chambers, each of said first and second chambers having an inlet end communicating with said canister inlet, said vent outlet being provided at an outlet end of the first chamber and said purge outlet being provided at an outlet end of said second chamber, wherein said first flow path, comprising an adsorption flow path, is defined through said first chamber and said second flow path, comprising a purge flow path, is defined through said second chamber.
- The second chamber may have at least one region of restricted cross sectional area, to provide a flow restriction in the purge flow path, and at least one region of greater cross sectional area, to provide an increased adsorption capacity.
- The second chamber may be provided with a fresh air inlet in a side region thereof.
- Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which:-
-
Fig. 1 is a schematic view of a known vapour recovery system during a canister load cycle, such as when the vehicle in inoperative. -
Fig. 2 is a schematic view of the vapour recovery system ofFig. 1 during a canister purge cycle; -
Fig. 3 is a schematic view of a vapour recovery system according to a first embodiment of the present invention; -
Fig. 4 is a schematic view of a vapour recovery system according to a second embodiment of the present invention; -
Fig. 5 is a schematic view of a vapour recovery system according to a third embodiment of the present invention; and -
Fig. 6 is a schematic view of a vapour recovery system according to a fourth embodiment of the present invention. - The flow restriction of the
purge flow path 17 is at least twice that of theadsorption flow path 16, thus vapour laden air from the headspace of the fuel tank preferentially flows through theadsorption flow path 16 from theinlet 13 to thevent outlet 14. - During rest, because the
adsorbent material 20 in thepurge flow path 17 adsorbs very little fuel vapour from the tank, it stays considerably clean. When the engine is started, vapours from first chamber 11 of the canister flow through the adsorbent material in thepurge flow path 17 due to the vacuum produced in the engine intake. Under such conditions, thepurge flow path 17 acts as delay line, so engine can warm up before fuel vapour from the canister reaches the engine. This improves engine performance and helps to control exhaust emissions. - In a second embodiment of the invention, illustrated in
Fig 4 , thesecond chamber 12 defining thepurge flow path 17 contains an adsorbent material 20b having a greater resistance to flow than the adsorbent material 20a contained in the first chamber, to further restrict the flow of vapour through the purge flow path. - In a third embodiment, as illustrated in
Fig 5 , thesecond chamber 12 contains narrowercross section regions 22,23 to provide a flow restriction in the purge flow path, and a wider cross section increasedvolume region 24 therebetween to provide a greater adsorption capacity. This improves the vapour recovery system performance. The largecross section region 24 of thesecond chamber 12 increases residence time of vapour within thesecond chamber 24, so peak concentrations of hydrocarbons at thepurge outlet 15 are reduced. - In a fourth embodiment, illustrated in
Fig 6 , a diluting feature can be implemented to further improve system performance. Afresh air inlet 30 is provided in a side region of thesecond chamber 12 to enable fresh air to be drawn into thepurge flow path 17 to further reduce the peak concentrations of hydrocarbons at thepurge outlet 15 - The vapour recovery system of the present invention can be used on simple systems, like powered two wheelers in developing countries, to avoid the use of control valves, reduce total vapour recovery system cost and improving system reliability as no movable parts are necessary.
- Various modifications and variations to the described embodiments of the inventions will be apparent to those skilled in the art without departing from the scope of the invention as defined in the appended claims. Although the invention has been described in connection with specific preferred embodiments, it should be understood that the invention as claimed should not be unduly limited to such specific embodiments.
Claims (8)
- A vapour recovery system for a vehicle fuel tank comprising a canister defining at least one chamber containing an adsorbent material for adsorbing fuel from fuel vapour laden air, the canister having an inlet for communication with the headspace of a vehicle fuel tank, a vent outlet for communication with the atmosphere and a purge outlet for communication with the air intake of the vehicle engine, a first flow path between the inlet and the vent outlet, and a second flow path between the inlet and the purge outlet, wherein the second flow path has a greater flow restriction and/or residence time than the first flow path.
- A vapour recovery system as claimed in claim 1, wherein the cross sectional area of the first flow path is greater than the cross sectional area of the second flow path.
- A vapour recovery system as claimed in claim 1, wherein the minimum cross sectional area of the first flow path is greater than the minimum cross sectional area of the second flow path.
- A vapour recovery system as claimed in any preceding claim, wherein the adsorbent material located in the second flow path has a higher restriction to the passage of air than the adsorbent material located in the first flow path.
- A vapour recovery system as claimed in any preceding claim, wherein the canister is provided with a further inlet for connection to a ambient air for supplying ambient air into said second flow path.
- A vapour recovery system as claimed in any preceding claim, wherein the canister is divided into first and second chambers, each of said first and second chambers having an inlet end communicating with said inlet at a first end thereof, said vent outlet being provided at an outlet end of the first chamber and said purge outlet being provided at an outlet end of said second chamber, wherein said first flow path, comprising an adsorption flow path, is defined through said first chamber and said second flow path, comprising a purge flow path, is defined through said second chamber.
- A vapour recovery system as claimed in claim 6, wherein the second chamber has at least one region of restricted cross sectional area, to provide a flow restriction in the purge flow path, and at least one region of greater cross sectional area, to provide an increased adsorption capacity.
- A vapour recovery system as claimed in claim 6 or claim 7, wherein said second chamber is provided with a fresh air inlet in a side region thereof.
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP07250510A EP1956228A1 (en) | 2007-02-08 | 2007-02-08 | Vapour recovery system for a vehicle fuel tank |
CN2008100054881A CN101239582B (en) | 2007-02-08 | 2008-02-05 | Vapor recovery system for a vehicle fuel tank |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP07250510A EP1956228A1 (en) | 2007-02-08 | 2007-02-08 | Vapour recovery system for a vehicle fuel tank |
Publications (1)
Publication Number | Publication Date |
---|---|
EP1956228A1 true EP1956228A1 (en) | 2008-08-13 |
Family
ID=38198022
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP07250510A Withdrawn EP1956228A1 (en) | 2007-02-08 | 2007-02-08 | Vapour recovery system for a vehicle fuel tank |
Country Status (2)
Country | Link |
---|---|
EP (1) | EP1956228A1 (en) |
CN (1) | CN101239582B (en) |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US9694310B2 (en) | 2014-08-11 | 2017-07-04 | Stant Usa Corp. | Fuel vapor recovery canister |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0631043A1 (en) * | 1993-06-19 | 1994-12-28 | Filterwerk Mann + Hummel Gmbh | Activated carbon filter for purging of a fuel tank |
US5957114A (en) | 1998-07-17 | 1999-09-28 | Ford Motor Company | Evaporative emission canister for an automotive vehicle |
US6237574B1 (en) * | 1999-04-20 | 2001-05-29 | Ford Motor Company | Evaporative emission canister for an automotive vehicle |
EP1507081A1 (en) | 2003-08-12 | 2005-02-16 | Delphi Technologies, Inc. | Evaporated fuel processing device |
-
2007
- 2007-02-08 EP EP07250510A patent/EP1956228A1/en not_active Withdrawn
-
2008
- 2008-02-05 CN CN2008100054881A patent/CN101239582B/en active Active
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0631043A1 (en) * | 1993-06-19 | 1994-12-28 | Filterwerk Mann + Hummel Gmbh | Activated carbon filter for purging of a fuel tank |
US5957114A (en) | 1998-07-17 | 1999-09-28 | Ford Motor Company | Evaporative emission canister for an automotive vehicle |
US6237574B1 (en) * | 1999-04-20 | 2001-05-29 | Ford Motor Company | Evaporative emission canister for an automotive vehicle |
EP1507081A1 (en) | 2003-08-12 | 2005-02-16 | Delphi Technologies, Inc. | Evaporated fuel processing device |
Also Published As
Publication number | Publication date |
---|---|
CN101239582A (en) | 2008-08-13 |
CN101239582B (en) | 2010-08-04 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
JP5394330B2 (en) | Evaporative fuel treatment device leak diagnosis device | |
JP5961026B2 (en) | Evaporative fuel processing equipment | |
US20080308075A1 (en) | Automotive fuel system for substantially reducing hydrocarbon emissions into the atmosphere, and method | |
US20080308074A1 (en) | Evaporative emissions canister with external membrane | |
KR100986062B1 (en) | Recirculation device of vaporized fuel for vehicle | |
JPH08232781A (en) | Evaporated fuel controller for internal combustion engine | |
JP5913024B2 (en) | Evaporative fuel processing equipment | |
US20080308073A1 (en) | Evaporative emissions canister having an integral membrane | |
JP2016109090A (en) | Canister | |
EP3575587B1 (en) | Evaporative emissions control system leak check module including first and second solenoid valves | |
JP3705398B2 (en) | Evaporative fuel control device for internal combustion engine | |
EP1956228A1 (en) | Vapour recovery system for a vehicle fuel tank | |
JP3399429B2 (en) | Evaporation gas suppression device for fuel tank | |
KR101262511B1 (en) | Fuel Tank vaporization Gas Purge System | |
US20080202481A1 (en) | Vapor recovery system for a vehicle fuel tank | |
JP4468769B2 (en) | Evaporative fuel adsorption device | |
JP3391209B2 (en) | Evaporative fuel control system for internal combustion engine | |
JP2002310008A (en) | Fuel vapor treatment equipment | |
US20210370760A1 (en) | Apparatus for purging fuel evaporation gas in fuel system | |
WO2023120119A1 (en) | Evaporated fuel adsorption device and method, evaporative emission control system and corresponding use | |
CN114109662A (en) | Fuel system for vehicle | |
JPH08232777A (en) | Vaporizing fuel control device for internal combustion engine | |
JP2009024561A (en) | Device for inhibiting discharge of fuel evaporated gas | |
JPH07180626A (en) | Evaporated fuel processing device | |
JPH10246156A (en) | Evaporation fuel recovering device for engine |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PUAI | Public reference made under article 153(3) epc to a published international application that has entered the european phase |
Free format text: ORIGINAL CODE: 0009012 |
|
17P | Request for examination filed |
Effective date: 20080110 |
|
AK | Designated contracting states |
Kind code of ref document: A1 Designated state(s): AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IS IT LI LT LU LV MC NL PL PT RO SE SI SK TR |
|
AX | Request for extension of the european patent |
Extension state: AL BA HR MK RS |
|
GRAP | Despatch of communication of intention to grant a patent |
Free format text: ORIGINAL CODE: EPIDOSNIGR1 |
|
AKX | Designation fees paid |
Designated state(s): AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IS IT LI LT LU LV MC NL PL PT RO SE SI SK TR |
|
GRAS | Grant fee paid |
Free format text: ORIGINAL CODE: EPIDOSNIGR3 |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN |
|
18D | Application deemed to be withdrawn |
Effective date: 20090505 |