Fuel reforming system

• US 4,143,620 A
• Filed: 09/16/1976
• Issued: 03/13/1979
• Est. Priority Date: 09/22/1975
• Status: Expired due to Term

• Current Assignee: Nippon Soken, Inc.
• Original Assignee: Nippon Soken, Inc.
• Inventors: Noguchi, Masaaki, Tanaka, Taro, Bunda, Tsuchio
• Primary Examiner(s): Myhre, Charles J.
• Assistant Examiner(s): Feinberg, Craig R.
• Application Number:
  US05/723,907
• Time in Patent Office: 908 Days
• Field of Search: 123/1 A, 123/3, 123/119 EC, 123/127, 123/122 AB, 123/122 G, 123/122 H, 60/288, 23/288 F, 23/288 FA, 23/288 FB, 23/288 FC
• US Class Current: 123/3
• CPC Class Codes: F02B 1/02 with positive ignition with non-timed positive ignition F02B9/06
• CPC Class Codes: F02B 1/04 with fuel-air mixture admission into cylinder
• CPC Class Codes: F02B 43/10 Engines or plants characterised by use of other specific gases, e.g. acetylene, oxyhydrogen
• CPC Class Codes: F02B 51/02 involving catalysts
• CPC Class Codes: F02M 23/10 dependent on temperature, e.g. engine temperature
• CPC Class Codes: F02M 27/02 by catalysts
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies
• CPC Class Codes: Y02T 10/30 Use of alternative fuels, e.g. biofuels

Abstract

A fuel reforming system for an internal combustion engine comprises a fuel circuit connected at its downstream end to the engine and including a carburetor for producing a rich air-fuel mixture and a fuel reforming reactor vessel containing a catalyst for facilitating a catalytic reformation of the mixture into a reformed gaseous mixture rich with free hydrogen. The carburetor is provided with a primary air intake passage with a venturi into which air and fuel are fed to produce a rich air-fuel mixture. The carburetor is also provided with a secondary air intake passage bypassing the venturi and connected to the fuel circuit downstream of the venturi. A valve is provided on the carburetor to control the cross-sectional area of the secondary air intake passage in accordance with the temperature in the engine or the reactor vessel, by the carburetor is adjusted according to the engine or reactor vessel temperature.

Claims

1. A fuel reforming system for converting a mixture of air and a fuel into a reformed gaseous mixture rich with free hydrogen and feeding the reformed gaseous mixture into an internal combustion engine, said system comprising:

a fuel circuit having a downstream end adapted to be connected to an internal combustion engine;

a carburetor disposed in said fuel circuit for producing a rich mixture of air and the fuel at an air-fuel ratio smaller than the stoichiometric air-fuel ratio of the mixture;

said carburetor including a primary air intake passage, means providing a venturi in said air intake passage, means for feeding the fuel into said venturi substantially in proportion to the flow of air through said venturi to cooperate therewith to produce the rich air-fuel mixture, and a secondary air intake passage bypassing said venturi and connected to said fuel circuit downstream of said venturi for supplying a secondary air to the rich air-fuel mixture produced in said venturi;

ignition means disposed in said fuel circuit downstream of said carburetor and being adapted to be operated, when required, to ignite and burn the air-fuel mixture in said fuel circuit;

a reactor vessel disposed in said fuel circuit and containing therein a catalyst for facilitating a catalytic reformation of said rich air-fuel mixture into said reformed gaseous mixture, said catalyst being disposed in heat exchange relationship with engine exhaust gases; and

air-fuel ratio adjusting means mounted on said carburetor and being operative in response to the variation in the temperature of said reactor vessel to vary the cross-sectional area of said secondary air intake passage for thereby controlling the air-fuel ratio of said rich air-fuel mixture so that when said temperature is not high enough to activate said catalyst, the air-fuel ratio of the rich mixture controlled by said air-fuel ratio adjusting means is controlled to allow a part of the mixture to be ignited by said ignition means to produce heat which raises the temperature of said reactor vessel, and when said temperature in the reactor vessel is high enough to activate said catalyst, the mixture is further enriched to the extent that the temperature is not further increased above a point where the reformation is substantially at a maximum.

2. A fuel reforming system according to claim 1, wherein said ignition means comprise a spark plug disposed on the upper side of a passage defined in said fuel circuit.

3. A fuel reforming system according to claim 1, wherein said fuel is methanol.

4. A fuel reforming system according to claim 1, wherein said air-fuel ratio adjusting means is operative in response to the increase in the temperature of engine exhaust gases.

5. A fuel reforming system according to claim 1, wherein said catalyst contains at least one of nickel and copper.

6. A fuel reforming system according to claim 1, wherein said air-fuel ratio adjusting means includes valve means for controlling the cross-sectional area of said secondary intake passage, means for actuating said valve means, a temperature detector mounted on said reactor vessel to detect the temperature in said reactor vessel for thereby emitting an electrical output signal representing the detected temperature, and means responsive to the electrical output signal to control said valve means actuating means;

said valve means being controlled to decrease the cross-sectional area of said secondary air intake passage to decrease the air-fuel ratio of the mixture produced in said venturi as the temperature in said reactor vessel rises.

7. A fuel reforming system according to claim 1, wherein said carburetor is disposed such that said primary air intake passage extends substantially horizontally.

8. A fuel reforming system according to claim 2, wherein said venturi providing means comprise a suction piston disposed in said primary air intake passage for movement in a direction transverse of the axis thereof.

9. A fuel reforming system for converting a mixture of air and a fuel into a reformed gaseous mixture rich with free hydrogen and feeding the reformed gaseous mixture into an internal combustion engine, said system comprising:

a fuel circuit having a downstream end adapted to be connected to an internal combustion engine;

a carburetor disposed in said fuel circuit for producing a rich mixture of air and the fuel at an air-fuel ratio smaller than the stoichiometric air-fuel ratio of the mixture;

said carburetor comprising a substantially horizontal primary air intake passage, a substantially closed space, a diaphragm extending across said space to divide the same into upper and lower chambers, a suction piston connected at one end to said diaphragm and extending into said primary air intake passage for movement transversely of the axis thereof to provide a variable venturi in said primary air intake passage, a second passage interconnecting said upper chamber and said primary air intake passage downstream of said venturi, a third passage communicating said lower chamber and the atmosphere, spring member disposed in said upper chamber for downwardly urging said diaphragm, a float chamber for said fuel, a nozzle extending from said float chamber to said venturi and open to said venturi to cooperate therewith to produce the rich air-fuel mixture, a needle movable with said suction piston to control the cross-sectional area of the opening of said nozzle in said venturi, a secondary air intake passage bypassing said venturi and connected to said primary air intake passage downstream of said venturi to supply a secondary air to the rich air-fuel mixture produced in said venturi, a temperature measuring chamber adjacent said secondary air intake passage, means disposed in said temperature measuring chamber and being expansible and contractible in response to the variation in the temperature in said temperature measuring chamber, and a valve member operatively associated with said expansible and contractible means to control the cross-sectional area of said secondary air intake passage for thereby controlling the air-fuel ratio of the air-fuel mixture produced in said venturi;

a throttle valve disposed in said fuel circuit downstream of said carburetor;

a spark plug disposed in said fuel circuit downstream of said throttle valve and being adapted to be operated, when required, to ignite and burn the rich air-fuel mixture;

a reactor vessel disposed in said fuel circuit downstream of said spark plug and containing a catalyst for facilitating a catalytic reformation of the air-fuel mixture into the reformed gaseous mixture; and

means for causing atmospheric air to flow through said reactor vessel in heat exchange relationship with said catalyst and then through said temperature measuring chamber;

said carburetor being arranged such that, when said catalyst is at a first temperature high enough to activate said catalyst, the air-fuel ratio of the mixture controlled by said valve member is much smaller than the stoichiometric air-fuel ratio of the mixture and such that, when said catalyst is at a second temperature lower than said first temperature, the air-fuel ratio of the mixture controlled by said valve member is still smaller than the stoichiometric air-fuel ratio but so large as to allow a part of the mixture to be ignited by said spark plug to produce heat in said fuel circuit.

10. A fuel reforming system according to claim 9, wherein said fuel is methanol.

11. A fuel reforming system according to claim 9, wherein said catalyst contains at least one of nickel and copper.