Method and system for detecting phev evap system recirculation tube reliability
AssigneeFord Global Technologies, LLC
InventorsRUSSELL RANDALL PEARCE, DENNIS SEUNG-MAN YANG, AED M. DUDAR
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Abstract
A method for detecting blockage within a recirculation tube of the evaporative emission control system of a PHEV measures the rise in interior temperature of a canister of the EVAP system, during the process of refueling, and notes an initial state of loading of the canister before refueling, indicative of the amount of hydrocarbons contained within the canister It is inferred that the recirculation tube is operative reliably if the rise in canister temperature is below a pre-determined temperature value.
Claims6
A method for verifying reliable operation of a recirculation tube of an evaporative emission control system of a plug-in hybrid electric vehicle, the recirculation tube having a first end connected to a fuel-filler neck of the vehicle fuel system, and a second end connected to a canister of the evaporative emission control system, the method comprising:
- detecting refueling;
- measuring canister temperature during refueling;
- inferring that the recirculation tube is operating reliably if a rise in canister temperature during refueling is below a pre-determined temperature value.
An evaporative emission control system for a plug-in hybrid electric vehicle, configured to verify reliable operation of a recirculation tube, comprising:
- a canister connected to the fuel tank of the vehicle;
- one or more temperature sensors positioned within the canister,;
- a fuel level indicator positioned within a system fuel tank;
- the recirculation tube having a first end connected to a fuel-filler neck of the vehicle fuel system, and a second end connected to the canister
- a controller, configured to
- receive an initial temperature signal from each temperature sensor;
- receive a final temperature signal from each temperature sensor;
- receive a signal from the fuel level indicator indicating the fuel volume added during the refueling operation;
- determining a recirculation threshold temperature;
- based upon the initial and final temperature signals and the added fuel volume signal, inferring the operational status of the recirculation tube.
The system of claim 6, configured to indicate that the recirculation tube is unreliable if the canister temperature rises by more than the pre-determined value.
Dependencies are inferred from the claim text.