Fuel vapor enrichment for exhaust exothermic catalyst light-off
First Claim
1. An engine system including an engine, an exhaust system, and a fuel system that communicates with the engine, comprising:
- a controller that communicates with the fuel system and that controls a first quantity of liquid fuel to the engine at a first air/fuel (A/F) ratio and a second quantity of vapor fuel to the engine at a second A/F ratio to provide a fuel mixture having a third A/F ratio; and
a secondary air source that operates in at least one of an on state and an off state and when operating in said on state supplies air to the exhaust system to increase said third A/F ratio,wherein said controller receives an indication of said at least one of said on state and said off state and adjusts said first quantity of liquid fuel and said second quantity of vapor fuel based on said indication, andwherein said controller further receives an exhaust A/F ratio from an exhaust A/F ratio sensor, compares said exhaust A/F ratio to a target A/F ratio range, and adjusts said first and second quantities when said exhaust A/F ratio is outside of said target A/F ratio range.
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Accused Products
Abstract
An engine system includes an engine with a secondary air source, a fuel system that communicates with the engine, and a controller that communicates with the fuel system. The controller controls a first quantity of liquid fuel to the engine at a first A/F ratio and a second quantity of vapor fuel to the engine at a second A/F ratio. The liquid and vapor fuel mixture has a third A/F ratio. A secondary air source provides additional air to the third A/F ratio. The controller determines an available A/F ratio of vapor fuel within the fuel tank and performs a comparison with a target A/F ratio range. The second quantity is set to zero if the A/F ratio of the vapor fuel is outside of the target A/F ratio range. The controller adjusts the first and second quantities based on a comparison between an exhaust A/F ratio and a target exhaust A/F ratio.
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Citations
20 Claims
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1. An engine system including an engine, an exhaust system, and a fuel system that communicates with the engine, comprising:
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a controller that communicates with the fuel system and that controls a first quantity of liquid fuel to the engine at a first air/fuel (A/F) ratio and a second quantity of vapor fuel to the engine at a second A/F ratio to provide a fuel mixture having a third A/F ratio; and a secondary air source that operates in at least one of an on state and an off state and when operating in said on state supplies air to the exhaust system to increase said third A/F ratio, wherein said controller receives an indication of said at least one of said on state and said off state and adjusts said first quantity of liquid fuel and said second quantity of vapor fuel based on said indication, and wherein said controller further receives an exhaust A/F ratio from an exhaust A/F ratio sensor, compares said exhaust A/F ratio to a target A/F ratio range, and adjusts said first and second quantities when said exhaust A/F ratio is outside of said target A/F ratio range. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A method of operating a combustion engine with a secondary air source, comprising:
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supplying liquid fuel having a first A/F ratio to the engine; receiving an indication of an operational state of the secondary air source; supplying liquid fuel at a second A/F ratio and vapor fuel at a third A/F ratio to the engine based on said indication to produce an exhaust A/F ratio; receiving a second exhaust A/F ratio from an exhaust A/F ratio sensor comparing said second exhaust A/F ratio to a target A/F ratio; and adjusting flow of said liquid fuel and said vapor fuel when said second exhaust A/F ratio is not equal to said target A/F ratio. - View Dependent Claims (8, 9, 10, 11, 12, 13)
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14. A method of operating a combustion engine with a secondary air source comprising:
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receiving an indication of an operational state of the secondary air source; determining a first A/F ratio of a first supply of liquid fuel; determining a second A/F ratio of a second supply of vapor fuel based on said first A/F ratio and said indication; supplying said first supply of liquid fuel and said second supply of vapor fuel to the engine; supplying air to exhaust gas from the engine while the secondary air source is operational; comparing an exhaust A/F ratio to a target A/F ratio; and adjusting said first supply and second supply when said exhaust A/F ratio is not equal to said target A/F ratio. - View Dependent Claims (15, 16, 17, 18, 19, 20)
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Specification