Fuel preheater for internal combustion engine

A fuel preheater for an internal combustion engine, comprising:

• a mixing chamber having a fluid inlet port and a fluid outlet port;
• a first conduit having opposed first and second ends, the first end thereof receiving environmental air, the second end thereof being connected to the fluid inlet port of said mixing chamber for delivering the environmental air into an interior region of said mixing chamber;
• at least one fuel injector mounted within said mixing chamber for atomizing a liquid fuel to form a fuel vapor within the interior region of said mixing chamber;
• a second conduit having opposed first and second ends, the first end thereof being connected to the fluid outlet port of said mixing chamber;
• a heating tube mounted about said second conduit and having opposed first and second ends, wherein each of the first and second ends of said heating tube is sealed about an exterior surface of said second conduit, said heating tube further having an exhaust inlet port and an exhaust outlet port;
• a third conduit having opposed first and second ends, the first end thereof being connected to the exhaust outlet port of said heating tube, the second end thereof being connected to an inlet port of said first conduit;
• an auxiliary fuel container for receiving an auxiliary volume of fuel;
• an air pipe having opposed first and second ends, the first end thereof receiving ambient air, the second end thereof being positioned in the auxiliary volume of fuel within the auxiliary fuel container to produce an auxiliary fuel vapor above a liquid surface of the auxiliary volume of fuel;
• and
• a fourth conduit for transferring the auxiliary fuel vapor to said second conduit in a region of said second conduit adjacent the second end thereof,
• wherein said heating tube receives a portion of exhaust from an internal combustion engine through the exhaust inlet port, the portion of the exhaust flowing about the exterior surface of said second conduit and being output from said heating tube into said third conduit, through the exhaust outlet port, the portion of the exhaust mixing with the environmental air to form a mixture of the environmental air, the portion of the exhaust, and the fuel vapor in the interior region of said mixing chamber, the mixture of the environmental air, the portion of the exhaust and the fuel vapor flowing through said second conduit and being preheated by heat transfer with the portion of the exhaust flowing through said heating tube, the mixture of the environmental air, the portion of the exhaust, and the fuel vapor being delivered to the internal combustion engine for combustion of the fuel vapor through the second end of said second conduit.

A method for preheating fuel for an internal combustion engine, comprising:

• providing a fuel preheater for an internal combustion engine, the fuel preheater including:
• a mixing chamber having a fluid inlet port and a fluid outlet port;
• a first conduit having opposed first and second ends, the first end thereof receiving environmental air, the second end thereof being connected to the fluid inlet port of said mixing chamber for delivering the environmental air into an interior region of said mixing chamber;
• at least one fuel injector mounted within said mixing chamber for atomizing a liquid fuel to form a fuel vapor within the interior region of said mixing chamber;
• a second conduit having opposed first and second ends, the first end thereof being connected to the fluid outlet port of said mixing chamber;
• a heating tube mounted about said second conduit and having opposed first and second ends, wherein each of the first and second ends of said heating tube is sealed about an exterior surface of said second conduit, said heating tube further having an exhaust inlet port and an exhaust outlet port, the first end of said heating tube being positioned adjacent the second end of said second conduit, and the second end of said heating tube being positioned adjacent the first end of said second conduit;
• and
• a third conduit having opposed first and second ends, the first end thereof being connected to the exhaust outlet port of said heating tube, the second end thereof being connected to an inlet port of said first conduit,
• receiving a portion of exhaust in the heating tube from an internal combustion engine through the exhaust inlet port;
• flowing the portion of the exhaust about the exterior surface of said second conduit and into said third conduit, through the exhaust outlet port;
• mixing the portion of the exhaust with the environmental air to form a mixture of the environmental air, the portion of the exhaust, and the fuel vapor in the interior region of said mixing chamber;
• flowing the mixture of the environmental air, the portion of the exhaust, and the fuel vapor through said second conduit;
• preheating the mixture of the environmental air, the portion of the exhaust and the fuel vapor by heat transfer with the portion of the exhaust flowing through said heating tube;
• and
• delivering the mixture of the environmental air, the portion of the exhaust, and the fuel vapor to the internal combustion engine for combustion of the fuel vapor through the second end of said second conduit.