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METHOD OF CONTROLLING CANISTER TEMPERATURE USING PIEZO-ELECTRIC MATERIAL TO IMPROVE EMISSIONS IN HEV

IP.com Disclosure Number: IPCOM000234770D
Publication Date: 2014-Feb-03
Document File: 1 page(s) / 235K

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The IP.com Prior Art Database

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    METHOD OF CONTROLLING CANISTER TEMPERATURE USING PIEZO-ELECTRIC MATERIAL TO IMPROVE EMISSIONS IN HEV

Vehicles sold in North America and other markets contain a carbon canister that adsorbs refueling (North America only), diurnal and running loss vapors. When the engine is running, by duty cycling the canister purge valve, the manifold vacuum draws clean air from the fresh side of the canister. The air flows through the carbon canister and removes hydrocarbons embedded in the activated carbons. This is commonly known as "purging". The desorbed hydrocarbons are mixed into the fuel vapor and combusted in engine. With limited engine purge time in a HEV vehicle, it's very challenging for the carbon canister to be cleaned out all the time. In order to pass emission testing, the canister must be purged out. It is well known that a heated canisters will result in better desorption of hydrocarbons from the canister, however, during refueling event, the canister is desired to be cool in order to maximize vapor adsorption.

Method

The described system encloses the carbon canister with a piezo-electric material. This provides heat or cooling as needed to optimize the purging and refueling. Wrapping the canister with alternating cool/hot surfaces of the piezo-electric material will accomplish both the heating and cooling functions. By sending electrical current through the piezo-electric material, one side of the surface will be hot and other side will be cool. The cooling st...