Abstract: A method includes calculating a first fuel evaporation gas density in a purge pump of a vehicle based on a pressure difference between a front end and a rear end of the purge pump, a radius of a fluid passage of the purge pump, a number of rotations of the purge pump, and an opening amount of a purge control solenoid valve, filtering the first fuel evaporation gas density, calculating a second fuel evaporation gas density in the purge pump based on the filtered first fuel evaporation gas density, calculating a third fuel evaporation gas density in a standard temperature and pressure state based on the second fuel evaporation gas density, a current pressure in the purge pump, and a current temperature in the purge pump, and calculating a concentration of hydrocarbon in a fuel evaporation gas in the purge pump based on the third fuel evaporation gas density.

Abstract: A method for increasing a purge rate of fuel evaporation gas of a vehicle may include: determining, by a controller, a first fuel evaporation gas density in a purge pump included in an active fuel evaporation gas purge system of the vehicle; filtering the first fuel evaporation gas density using a filter for controlling an amount of change in the first fuel evaporation gas density; determining a second fuel evaporation gas density in the purge pump based on the filtered first fuel evaporation gas density; determining a third fuel evaporation gas density in a standard temperature and pressure state; determining a concentration of hydrocarbon within the fuel evaporation gas based on the third fuel evaporation gas density; and increasing the purge rate of the fuel evaporation gas based on the hydrocarbon concentration in the fuel evaporation gas.

Abstract: A method controls an opening speed of a purge valve according to the purge gas concentration implemented by an active purge system (APS). A purge controller varies, when a valve opening speed of a purge control solenoid valve (PCSV) is controlled, the valve opening speed of the PCSV using any one among a low concentration rate coefficient, a high concentration rate coefficient, a coolant temperature rate coefficient, and an ambient air temperature rate coefficient, and performs the purge control using a difference between the valve opening speeds, and thus dualizes the valve opening speed of the PCSV according to a hydrocarbon (HC) concentration, thereby stably controlling the air-fuel ratio, and simultaneously, securing the purge rate and relatively stably control an air-fuel ratio in a state of high concentration purge execution.

Abstract: An embodiment is a method including controlling a purge fuel amount of an active purge system (APS), the controlling including correcting the purge fuel amount using a primary weighting factor obtained using an ambient air temperature and a hydrocarbon (HC) concentration in purge gas fuel as input values, and correcting the corrected purge fuel amount using a secondary weighting factor due to a purge learning value. Some embodiments further include controlling of the purge fuel amount applies a purge execution condition, and the purge execution condition on the basis of a negative pressure of an intake manifold and a vehicle speed of the vehicle in which a purge flow rate exhibits as being greater than or equal to a predetermined value.