# US 8,464,518 B2 · Fuel vapor enrichment for exhaust exothermic catalyst light-off > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,464,518 B2 - Document ID: US8464518B2 - Status: Granted - Kind: B2 - Application number: 10/739,616 - Filed: 2003-12-18 - Published: 2005-06-23 - Granted: 2013-06-18 - Earliest claimed: 2003-12-18 - Assignees: GM Global Technology Operations LLC - Applicants: Frank Ament; Mary Beth Furness - Inventors: Frank Ament; Mary Beth Furness - Web page: https://patentgrep.com/patent/US8464518B2 ## CPC - F02D 41/064: {at cold start (F02D41/067 takes precedence)} - F01N 3/32: using air pump (using jet air pumps F01N3/34; pumps in general F04) - F02D 41/0032: {Controlling the purging of the canister as a function of the engine operating conditions} - F02D 41/0045: {Estimating, calculating or determining the purging rate, amount, flow or concentration} - F02M 25/089: {Layout of the fuel vapour installation} - Y02T 10/12: Improving ICE efficiencies - F02D: CONTROLLING COMBUSTION ENGINES (vehicle fittings, acting on a single sub-unit only, for automatically controlling vehicle speed B60K31/00; conjoint control of vehicle sub-units of different type or different function, road vehicle drive control systems for purposes other than the control of a single sub-unit B60W) - F01N: GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL-COMBUSTION ENGINES (arrangements in connection with gas exhaust of propulsion units in vehicles B60K13/00; combustion-air intake silencers specially adapted for, or arranged on, internal-combustion engines F02M35/00; protecting against, or damping, noise in general G10K11/16) - F02M: SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## 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. ## Claims ### 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, 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. ### Claim 2 (depends on 1) The engine system of claim 1 wherein said first A/F ratio is lower than a stoichiometric A/F ratio. ### Claim 3 (depends on 1) The engine system of claim 1 wherein said controller controls an initial A/F ratio of liquid fuel supplied to the engine and estimates said third A/F ratio based thereon. ### Claim 4 (depends on 1) The engine system of claim 1 wherein said controller calculates an NF ratio offset based on said exhaust A/F ratio and a target A/F ratio. ### Claim 5 (depends on 1) The engine system of claim 1 wherein said controller determines an available A/F ratio of vapor fuel within the fuel system, performs a comparison with a target A/F ratio range, and wherein said second quantity is set to zero if said A/F ratio of said vapor fuel is outside of said target A/F ratio range. ### Claim 6 (depends on 5) The engine system of claim 5 wherein said controller adjusts said available A/F ratio based on an A/F ratio offset. ### Claim 7 A method of operating a combustion engine with a secondary air source, comprising: 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. ### Claim 8 (depends on 7) The method of claim 7 wherein said second A/F ratio is less than a stoichiometric A/F ratio. ### Claim 9 (depends on 7) The method of claim 7 further comprising calculating said third A/F ratio based on said first A/F ratio. ### Claim 10 (depends on 7) The method of claim 7 further comprising controlling a valve in communication with a supply of vapor fuel to regulate said vapor fuel. ### Claim 11 (depends on 7) The method of claim 7 further comprising: determining an A/F ratio offset based on said second exhaust A/F ratio and said target A/F ratio; storing said A/F ratio offset; and adjusting said third A/F ratio based on said A/F ratio offset. ### Claim 12 (depends on 7) The method of claim 7 further comprising: determining an available A/F ratio of vapor fuel within a fuel tank; and comparing said available A/F ratio with a target A/F ratio range, wherein said third A/F ratio is zero if said available A/F ratio is outside of said target A/F ratio range. ### Claim 13 (depends on 12) The method of claim 12 further comprising adjusting said available A/F ratio based on an A/F ratio offset. ### Claim 14 A method of operating a combustion engine with a secondary air source comprising: 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. ### Claim 15 (depends on 14) The method of claim 14 wherein said first A/F ratio is less than a stoichiometric A/F ratio. ### Claim 16 (depends on 14) The method of claim 14 further comprising controlling a valve in communication with a supply of vapor fuel to regulate said second supply of vapor fuel. ### Claim 17 (depends on 14) The method of claim 14 further comprising: determining a third A/F ratio of a third supply of liquid fuel supplied to said engine during starting; and calculating said second A/F ratio based on said third A/F ratio. ### Claim 18 (depends on 17) The method of claim 17 further comprising: determining an A/F ratio offset based on said exhaust A/F ratio and said target A/F ratio; storing said A/F ratio offset; and adjusting said third A/F ratio based on said A/F ratio offset. ### Claim 19 (depends on 14) The method of claim 14 further comprising: determining an available A/F ratio of vapor fuel within a fuel tank; and comparing said available A/F ratio with a target A/F ratio range, wherein said second supply is zero if said available A/F ratio is outside of said target A/F ratio range. ### Claim 20 (depends on 19) The method of claim 19 further comprising adjusting said available A/F ratio based on an A/F ratio offset.