Methods and systems for fuel vapor control

Abstract

Various methods and systems are provided for reducing pressure in a fuel tank of a fuel system of an engine. In one example, cooling fluid is routed from an air conditioner of a cooling system to a vapor cooler disposed in a vapor space of the fuel tank such that fuel vapor in the fuel tank may be condensed and routed to a fuel pump for delivery to the engine, thereby reducing a fuel tank pressure.

Description

Technical field [0001] The present invention relates to pressure control in a fuel tank in a vehicle such as a hybrid vehicle. Background technique [0002] Reducing engine operating time in hybrid vehicles can realize the benefits of fuel economy and reduced regulated emissions. However, the shorter engine operating time combined with the low intake manifold vacuum may cause insufficient flushing of fuel vapor from the fuel vapor canister connected between the intake manifold and the fuel tank. Furthermore, under conditions such as relatively warm ambient temperatures, when the production of fuel vapor in the fuel tank increases, insufficient flushing of the fuel vapor canister results in an increase in hydrocarbon emissions to the atmosphere. Summary of the invention [0003] The inventor herein recognized the above problem and invented a method to at least partially solve this problem. In one example, a method for a fuel system is provided. The method includes, in response t...

AI Technical Summary

Problems solved by technology

However, shorter engine run times combined with low intake manifold vacuum may result in insufficient flushing of fuel vapors from the fuel vapor canister connected between the intake manifold and fuel tank

Also, under conditions such as warmer ambient temperatures, when fuel vapor generation in the fuel tank increases, insufficient flushing of the fuel vapor canister results in increased hydrocarbon emissions to the atmosphere

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