SYSTEMS AND METHODS FOR DEPRESSURIZING A FUEL TANK

摘要

Methods and systems are provided for depressurizing a fuel tank prior to refueling the fuel tank. One example method includes adjusting a latchable refueling valve to a latched open position to enable vapor flow from the fuel tank to a vapor canister at a first rate, and responsive to fuel tank pressure being higher than a first pressure threshold after a pre-determined duration at the latched open position, modifying the latchable refueling valve to an unlatched open position. The unlatched open position of the latchable refueling valve enables a second flow rate for fuel vapors, the second flow rate higher than the first flow rate at the latched open position.

主权项

1. A method, comprising:
adjusting a latchable valve to a first, latched position via a voltage pulse, the first, latched position enabling depressurization of a fuel tank; and responsive to a pressure in the fuel tank higher than a first pressure threshold after a pre-determined duration,
moving the latchable valve to a second, unlatched position with a more continuously applied voltage, the second, unlatched position more open than the first latched position.