Evaporative emission control in battery powered vehicle with gasoline engine powered generator

摘要

A plug-in hybrid vehicle is driven by one or more electric motors powered by a battery system with supplemental electric power provided by a gasoline engine powered generator. A canister (50), connected by a fuel vapor vent passage, is used to admit and temporarily adsorb fuel vapor from a vehicle fuel tank (18) during refueling. The canister (50) also has a first fuel vapor and air flow passage for venting the canister (50) and introducing ambient air (in the reverse flow direction) for removing vapor stored in the canister (50) during tank refueling. The canister (50) has a second passage for conducting air and purged vapor from the canister (50) to the operating engine. The first and second passages are opened only during engine operation for purging of stored fuel vapor. The first flow passage is selectively opened when the tank is being refueled. The sealed fuel system eliminates diurnal fuel tank vapor generation and canister bleed emissions.