Liquefied gas fuel supply system

• US 5,540,208 A
• Filed: 09/12/1995
• Issued: 07/30/1996
• Est. Priority Date: 09/13/1994
• Status: Expired due to Fees

• Current Assignee: Nabco Ltd. (Nabtesco Corporation)
• Original Assignee: Nabco Ltd. (Nabtesco Corporation)
• Inventors: Kikutani, Isao
• Primary Examiner(s): Solis, Erick R.
• Application Number:
  US08/527,366
• Time in Patent Office: 322 Days
• Field of Search: 123/527, 123/529, 123/3, 123/DIG. 12, 123/518, 62/48.1, 62/48.2, 62/48.4, 62/50.2, 62/323.1
• US Class Current: 123/518
• CPC Class Codes: F02B 43/00 Engines characterised by operating on gaseous fuels; Plants including such engines engines characterised by the gas-air charge being ignited by compression ignition of an additional fuel F02B7/06; engines convertible from gas to other fuel consumption F02B69/04
• CPC Class Codes: F02D 19/027 Determining the fuel pressure, temperature or volume flow, the fuel tank fill level or a valve position
• CPC Class Codes: F02M 21/0224 Secondary gaseous fuel storages
• CPC Class Codes: F02M 21/0227 Means to treat or clean gaseous fuels or fuel systems, e.g. removal of tar, cracking, reforming or enriching
• CPC Class Codes: F02M 21/0245 High pressure fuel supply systems; Rails; Pumps; Arrangement of valves
• CPC Class Codes: F02M 21/0287 characterised by the transition from liquid to gaseous phase F02M21/06 takes precedence; Injection in liquid phase; Cooling and low temperature storage
• CPC Class Codes: F02M 21/06 Apparatus for de-liquefying, e.g. by heating
• CPC Class Codes: F02M 27/02 by catalysts
• CPC Class Codes: F17C 2205/0332 Safety valves or pressure relief valves
• CPC Class Codes: F17C 2205/0335 Check-valves or non-return valves
• CPC Class Codes: F17C 2221/033 Methane, e.g. natural gas, CNG, LNG, GNL, GNC, PLNG
• CPC Class Codes: F17C 2223/0161 cryogenic, e.g. LNG, GNL, PLNG
• CPC Class Codes: F17C 2223/033 Small pressure, e.g. for liquefied gas
• CPC Class Codes: F17C 2227/0302 by heating
• CPC Class Codes: F17C 2227/0393 using a vaporiser
• CPC Class Codes: F17C 2265/032 by recovery
• CPC Class Codes: F17C 2265/04 using an independent energy source, e.g. battery
• CPC Class Codes: F17C 2265/066 for feeding engines for propulsion
• CPC Class Codes: F17C 2270/0184 Fuel cells
• CPC Class Codes: F17C 9/02 with change of state, e.g. vaporisation
• CPC Class Codes: H01M 16/006 : of fuel cells with rechargeable batteries
• CPC Class Codes: H01M 8/0612 : from carbon-containing material
• CPC Class Codes: Y02E 60/10 : Energy storage using batteries
• CPC Class Codes: Y02E 60/50 : Fuel cells
• CPC Class Codes: Y02T 10/30 : Use of alternative fuels, e.g. biofuels

Abstract

A system for vaporizing liquefied gas fuel supplied from a fuel tank and supplying it to an internal combustion engine includes a release path for releasing spontaneously evaporated fuel gas in said tank out of the tank. A catalytic burner is disposed in the release path for decomposing the fuel gas into hot steam and carbon dioxide. A release control valve disposed between the catalytic burner and the fuel tank selectively causes the burner and the fuel tank to communicate and to be decoupled from each other.

Claims

1. A liquefied gas fuel supply system comprising:

a fuel tank in which a liquefied gas fuel is stored;

fuel supplying means for vaporizing said liquefied gas fuel for supply to an internal combustion engine;

a release path for releasing outside said fuel tank, evaporated gas fuel resulting from evaporation of said liquefied gas fuel within said fuel tank;

catalytic decomposing means disposed in said release path for chemically decomposing said evaporated gas fuel;

release control means disposed in said release path between said decomposing means and said fuel tank, said release control means selectively assuming a coupling state for causing said decomposing means to communicate with said fuel tank, and a decoupling state in which said decomposing means is decoupled from said fuel tank.

2. The liquefied gas fuel supply system according to claim 1 wherein said system further comprises:

switching means disposed between said release control means and said fuel tank, said switching means being switchable between a first coupling state for causing said release control means to communicate with said fuel tank, and a decoupling state in which said release control means is decoupled from said fuel tank, said switching means being placed in said first coupling state when the pressure within said fuel tank is close to the withstanding pressure of said fuel task;

a buffer tank disposed between said switching means and said release control means; and

supply control means disposed between said buffer tank and said fuel supplying means, said supply control means selectively assuming a coupling state for causing said buffer tank to communicate with said fuel supplying means, and a decoupling state in which said buffer tank is decoupled from said fuel supplying means, said supply control means assuming said coupling state when said internal combustion engine is operating and, at the same time, fuel gas is present in said buffer tank.

3. The liquefied gas fuel supply system according to claim 2 wherein said release control means assumes its coupling state when the pressure of fuel gas in said buffer tank reaches a value close to the withstanding pressure of said buffer tank.

4. The liquefied gas fuel supply system according to claim 2 wherein said switching means further has a second coupling state for causing said fuel supplying means to communicate with said fuel tank, said switching means assuming said second coupling state when the pressure of evaporated fuel gas within said fuel tank reaches a value close to the bottling pressure of said fuel tank.

5. The liquefied gas fuel supply system according to claim 2 wherein said fuel supply means includes a surge tank, and said liquefied gas fuel supply means further comprises communication means disposed between the outlet of said surge tank and said buffer tank, for causing said surge tank to communicate with said buffer tank when the pressure within said surge tank reaches a value close to the withstanding pressure of said surge tank.

6. The liquefied gas fuel supply system according to claim 1 wherein said decomposing means includes a catalyst layer which decomposes fuel gas supplied thereto into carbon dioxide and water vapor.

7. The liquefied gas fuel supply system according to claim 1 wherein said decomposing means includes means for producing hydrogen from gas fuel supplied thereto and supplying the produced hydrogen to a fuel cell as a fuel therefor.

8. The liquefied gas fuel supply system according to claim 1, further comprising:

pressure control means disposed between said release control means and said fuel tank for coupling evaporated fuel gas in said fuel tank to said release control means when the pressure within said fuel tank reaches a value close to the withstanding pressure of said fuel tank;

a buffer tank disposed between said pressure control means and said release control means; and

re-liquefying means disposed between said buffer tank and said fuel tank for liquefying fuel gas in said buffer tank and supplying the liquefied gas to said fuel tank.

9. The liquefied gas fuel supply system according to claim 8, further comprising:

supply control means disposed between said buffer tank and said re-liquefying means, said supply control means selectively assuming a coupling state for causing said buffer tank to communicate with said re-liquefying means, and a decoupling state for decoupling said buffer tank from said re-liquefying means, said supply control means assuming said coupling state when fuel gas is present within said buffer tank.

10. The liquefied gas fuel supply system according to claim 8 wherein said fuel supplying means includes a surge tank, and said liquefied gas fuel supply means further comprises communication means disposed between the outlet of said surge tank and said buffer tank, for causing said surge tank to communicate with said buffer tank when the pressure within said surge tank reaches a value close to the withstanding pressure of said surge tank.

11. A liquefied gas fuel supply system comprising:

a fuel tank in which a liquefied gas fuel is stored;

fuel supplying means for vaporizing said liquefied gas fuel for supply to an internal combustion engine;

a release path for releasing outside said fuel tank, evaporated gas fuel resulting from evaporation of said liquefied gas fuel within said fuel tank;

catalytic decomposing means in said release path for chemically decomposing gas evaporated from the liquefied gas fuel within said fuel tank; and

switching means switchable between a first state for supplying evaporated gas to said decomposing means and a second state for supplying evaporated fuel gas to said fuel supplying means, said switching means being switched to said second state when the pressure within said fuel tank exceeds a first pressure related to a maximum bottling pressure of said fuel tank, and switched to said first state when the pressure within said fuel tank exceeds a second pressure higher than said first pressure, said second pressure being related to the withstanding pressure of said fuel tank.

12. The liquefied gas fuel supply system according to claim 11 wherein said fuel supplying means includes a surge tank, and said system further comprises a pressure control valve disposed between said surge tank and said decomposing means for coupling fuel gas in said surge tank to said decomposing means when the pressure within said surge tank exceeds a pressure related to the withstanding pressure of said surge tank.

13. A liquefied gas fuel supply system comprising:

a fuel tank in which a liquefied gas fuel is stored;

fuel supplying means for vaporizing said liquefied gas fuel for supply to an internal combustion engine, the fuel supplying means including a surge tank;

a buffer tank;

a pressure control valve for coupling gas evaporated from said liquefied fuel gas within said fuel tank to said buffer tank when the pressure of the evaporated fuel gas exceeds a value related to the withstanding pressure of said fuel tank;

re-liquefying means disposed between said buffer tank and said fuel tank for re-liquefying fuel gas within said buffer tank and supplying the re-liquefied gas to said fuel tank; and

a pressure control valve disposed between said surge tank and said buffer tank for coupling fuel gas in said surge tank to said buffer tank when the pressure within said surge tank exceeds a pressure related to the withstanding pressure of said surge tank.