Evap-System - New Actuators Facing the Future Requirements for Purge Flow Management

On the background of the model year '94/'95 legal regulations the evaporative emission system and especially the purge flow management has to change significantly.

A strategy is shown, which enables to solve the problems of choosing the right actuators and electrical control.

With the assistance of a numerical method an analysis of the canister purge valve mass flow characteristics is carried out. The most important functional quality critirea dynamic range, macro- and micro dosing efficiencies are calculated for some valves, which are in use or in development.