One kind of fuel evaporative emission control system and method

The present invention relates to a method and system for controlling the fuel evaporative emission, the method determines non canister purge execution condition depending on the engine electronic control unit, the maximum and minimum purification purification purification three types, for each type of purification, by desorption control valve opening, the complete purification of the charcoal canister, such that the canister before reaching saturation, the load in the activated carbon in the fuel tank boil-off gas with the air, flows through the cylinder participate in the combustion and desorption valves so as to purify the carbon canister effect, to achieve control of the fuel evaporative emissions. Fuel gas is not evaporated into the atmosphere assignment, but is burned fuel savings played a role in the cylinder, the automobile of the specified quality indicators.