WO1995014856B1 - Internal combustion engine fuel supply system and method - Google Patents

Abstract

A fuel supply system and method incorporates a fuel pump (12) for pressurizing liquid fuel for use in an internal combustion engine (98). The pressurized fuel is supplied to a fuel injector (20) mounted on a vaporization chamber (25); actuation signals applied to the fuel injector (20) atomize a metered quantity of liquid fuel into the chamber (25). The atomized fuel travels a tortuous path in the chamber (25), striking chamber walls (75, 77, 80, 81) heated by hot exhaust gas from the internal combustion engine (98). Vaporized fuels delivered from the vaporization chamber (25) to a mixing chamber (96) to be mixed with air to form a combustible fuel/air mixture. Air supplied to the mixing chamber (96) is heated by exhaust heat prior to delivery to the mixing chamber (96). The combustible fuel/air mixture is then supplied to the intake manifold of the internal combustion engine (98).

Claims

AMENDED CLAIMS[received by the International Bureau on 10 July 1995 (10.07.95); original claims 1, 4 and 12 amended; remaining claims unchanged (7 pages)]

1. In an internal combustion engine adapted to operate using a vaporized fuel and air mixture and having an intake manifold for supplying said mixture to a combustion chamber therein, said engine producing hot exhaust gases, an improved fuel supply system comprising:

(a) storage means for storing liquid fuel;

(b) fuel pressuring means connected to said storage means for pressurizing and delivering fuel from said storage means; (c) a vaporization chamber positioned within said exhaust gases for vaporizing liquid fuel;

(d) a liquid fuel atomizing means connected to receive pressurized fuel from said fuel pressurizing means and positioned to deliver a measured quantity of atomized liquid fuel into said vaporization chamber;

(e) fuel/air mixing means connected to receive fuel vapor from said vaporization chamber, said mixing means also connected to receive air for mixing with said fuel vapor; and

(f) means connecting -. id fuel/air mixing means to said internal combustion engine intake manifold for delivering fuel/air mixture to the combustion chamber thereof.

2. The combination set forth in Claim 1 wherein said fuel atomizer is an electrically actuated fuel injector.

3. The combination set forth in Claim 2 including a plurality of sensors for detecting engine operating conditions and generating electrical signals in response thereto, means connected to said sensors responsive to said signals for generating fuel injector actuating signals, and means connecting said actuating signals to said fuel injector for actuating said injector to deliver a metered quantity of atomized fuel.

4. In an internal combustion engine adapted to operate using a vaporized fuel and air mixture and having an intake manifold for supplying said mixture to a combustion chamber therein, said engine producing hot exhaust gases, an improved fuel supply system comprising:

(a) storage means for storing liquid fuel;

(b) fuel pressuring means connected to said storage means for pressurizing and delivering fuel from said storage means;

(c) a vaporization chamber for vaporizing liquid fuel, said chamber immersed in said hot exhaust gases for extracting heat from said gases for vaporizing liquid fuel in said chamber; (d) a liquid fuel atomizing means connected to receive pressurized fuel from said fuel pressurizing means and positioned to deliver atomized liquid fuel into said vaporization chamber;

(e) fuel/air mixing means connected to receive fuel vapor from said vaporization chamber, e d mixing means also connected to rec e air for mixing with s d fuel vapor; and

(f) means connectir said fuel/air mixing means to said internal combustion engine intake manifold for delivering fuel/air mixture to the combustion chamber thereof.

5. The combination set fcrth in Claim 4 wherein said fuel atomizing means is mounted on said vaporizat: -ι chamber.

6. The combinε _on set forth in

Claim 4 wherein said vaporization chamber is formed to provide a tortuous path for fuel traveling therethrough and wherein the chamber is formed having walls of uniform thickness to facilitate heat transfer from the hot exhaust gases to the fuel in the chamber.

7. The combination set forth in Claim 6 wherein said vaporization chamber includes spaced apart top and bottom walls formed to provide a sawtooth path therebetween for fuel and vapor therein.

8. The combination set forth in Claim 7 wherein said vaporization chamber includes sidewalls extending between said top and bottom walls, and wherein said sidewalls diverge in the direction of vapor flow at a predetermined angle and then converge at a second predetermined angle.

9. The combination set forth in

Claim 8 wherein the the sidewalls diverge at an angle from twenty degrees to ninety degrees and preferably approximately sixty degrees and wherein the sidewalls converge at an angle greater than the angle of divergence and preferably approximately ninety degrees.

10. The combination set forth in Claim 4 wherein said vaporization chamber includes interior surfaces having a layer of catalytic material thereon.

11. The combination set forth in Claim 10 wherein said catalytic material is platinum plated on said surfaces.

12. In an internal combustion engine adapted to operate using a vaporized fuel and air mixture and having an intake manifold for supplying said mixture to a combustion chamber therein, said engine producing hot exhaust gases, an improved fuel supply system comprising:

(a) storage means for storing liquid fuel;

(b) fuel pressuring means connected to said storage means for pressurizing and delivering fuel from said storage means;

(c) a vaporization chamber positioned within said exhaust gases for vaporizing liquid fuel; (d) a liquid fuel atomizing means connected to receive pressurized fuel from said fuel pressurizing means and positioned to deliver a measured quantity of atomized liquid fuel into said vaporization chamber;

(e) fuel/air mixing means connected to receive fuel vapor from said vaporization chamber and to receive warmed air for mixing with said fuel vapor;

(f) air warming means connected to said fuel/air mixing means for receiving outside air and directing said air to a heat exchanger for extracting heat from said exhaust gas and warming said air for delivery to said fuel/air mixing means; and

(g) means connecting said fuel/air mixing means to said internal combustion engine intake manifold for delivering fuel/air mixture to the combustion chamber thereof.

13. The combination set forth in Claim 12 including means responsive to the temperature of air supplied to said fuel/air mixing means for controlling the proportions of warmed and unwarmed air for delivery to said mixing means .

14. A method for supplying fuel to an internal combustion engine adapted to operate using a vaporized fuel and air mixture and having an intake manifold for supplying said mixture to a combustion chamber therein, said engine producing hot exhaust gases, comprising the steps:

(a) pressurizing liquid fuel;

(b) atomizing the pressurized liquid fuel;

(c) directing a metered quantity of said atomized fuel into a vaporization chamber;

(d) vaporizing said atomized fuel in said vaporization chamber by directing said hot exhaust gases into contact with said vaporization chamber;

(e) mixing the resulting vaporized fuel with air to form a fuel/air mixture; and

(f) delivering said fuel/air mixture to the intake manifold of said internal combustion engine.

15. A method for supplying fuel to an internal combustion engine adapted to operate using a vaporized fuel and air mixture and having an intake manifold for supplying said mixture to a combustion chamber therein, said engine producing hot exhaust gases, comprising the steps :

(a) pressurizing liquid fuel;

(b) atomizing the pressurized liquid fuel; (c) directing a metered quantity of said atomized fuel into a vaporization chamber;

AMENDED SHEET (ARTICLE 13) (d) vaporizing said atomized fuel in said vaporization chamber by directing said hot exhaust gases into contact with said vaporization chamber

5 while simultaneously heating air with heat extracted from said hot exhaust gases;

(e) mixing the resulting vaporized fuel with said heated air to

10 form a fuel/air mixture; and

(f) delivering said fuel/air mixture to the intake manifold of said internal combustion engine.