Calculation of flow in an air system

摘要

A method is provided for determining an air flow in a vehicle air conditioning system that comprises an inlet; a plurality of outlets; at least one air duct for guiding air from the inlet to the outlets, each air duct being characterized by a predetermined flow resistance coefficient; at least one flap characterized by a flow resistance based on a degree of opening of the flap; and a fan for creating an air flow from the inlet to an outlet. The method comprises determining a total equivalent flow resistance between a predetermined location in the system and an interior of the vehicle, wherein flow resistances are treated as resistances in an electric circuit, and a total equivalent flow resistance is determined. Treating a pressure drop as equivalent with a voltage drop, the air flow can be determined, as the pressure is equal to the resistance times the flow squared.

主权项

1. A method for determining an air flow in a vehicle air conditioning system, wherein the system comprises at least one inlet; a plurality of outlets; at least one air duct for guiding air from the at least one inlet to the plurality of outlets, each air duct having a predetermined flow resistance coefficient; at least one flap having a flow resistance based on a degree of opening of the at least one flap; and a fan for creating an air flow from the at least one inlet to at least one of the plurality of outlets; the method comprising:
determining a total equivalent flow resistance ktot between a predetermined location in the system and an interior of the vehicle, wherein flow resistances arranged in series are added to each other and wherein an equivalent flow resistance k0 representing a first flow resistance k1 and a second flow resistance k2 arranged in parallel is determined as:k0=k1⁢k2k1+k2+2⁢k1⁢k2; determining a pressure difference P between the predetermined location in the system and the interior of the vehicle; and determining total air flow F into the interior of the vehicle asF=Pktot.