Flow measurement and control
AssigneeFord Global Technologies, LLC
InventorsAllan Joseph Kotwicki, John David Russell
Life of this patent
Estimating the term…
Abstract
An exhaust gas recirculation systems directs exhaust gasses from an exhaust manifold to an intake manifold of an internal combustion engine. The exhaust gasses travel from the exhaust manifold, first passing through a flow control valve and then through a measuring orifice before entering the intake manifold. Pressure difference across the orifice is used, along with correction factors based on the pressure difference and pressure downstream of the orifice, to measure and control exhaust gas flow.
Claims20
A flow measurement system for measuring exhaust gas flow from an exhaust manifold of an internal combustion engine to an intake manifold of the engine, the system comprising:
- a flow control valve having a variable orifice positioned in an exhaust gas recirculation path between the exhaust manifold and intake manifold of the engine;
- a fixed orifice area located in said path and downstream of said valve;
- and
- a computer for measuring a first pressure downstream of said fixed orifice area, measuring a differential pressure across said fixed orifice area orifice, and calculating a mass flow based on said first pressure and said differential pressure.
An article of manufacture comprising:
- a housing;
- a flow control valve contained in said housing, said flow control valve having a variable area orifice disposed within a gas flow passage and connected to an inlet portion of said passage;
- a fixed area orifice disposed within said passage and connected to an outlet portion of said passage;
- a first differential pressure sensor coupled across said fixed area orifice to measure a differential pressure across said fixed area orifice;
- and
- a second pressure sensor coupled to said outlet portion to measure outlet pressure.
A method for measuring flow from an engine exhaust to and engine intake wherein the flow passes through a flow control valve and then a fixed area measuring orifice, the method comprising;
- calculating a pressure difference across the measuring orifice based at least on a first measured signal;
- calculating a pressure downstream of the measuring orifice representative of manifold pressure based at least on a second measured signal;
- calculating a flow based on said downstream pressure and said pressure difference;
- determining a desired flow based on engine operating conditions;
- and
- adjusting the flow control valve based on said desired flow and said calculated flow.
An article of manufacture comprising:
- a housing;
- a gas flow passage within said housing;
- a flow control valve contained in said housing, said flow control valve having a variable area orifice disposed within said gas flow passage and connected to an inlet portion of said passage;
- a fixed area orifice disposed within said passage and connected to an outlet portion of said passage;
- a first pressure sensor coupled across said fixed area orifice to measure a differential pressure across said fixed area orifice;
- and
- a second pressure sensor coupled to said outlet portion to measure outlet pressure.
Dependencies are inferred from the claim text.