Exhaust gas recirculation control in a dynamic skip fire engine
AssigneesTula Technology, Inc., Cummins Inc.
InventorsXin Yuan, Shikui Kevin Chen, Jennifer K. Light-Holets, Scott R. Bardakjy
Life of this patent
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Abstract
A system and method of integrating an engine having dynamic skip fire control with an exhaust gas recirculation system in a turbocharged internal combustion engine is described. An engine control system determines an appropriate firing pattern based at least in part on a desired exhaust gas recirculation flow rate. Signals from sensors in the intake manifold and exhaust system may also be used as part of a feedback loop to determine a desired exhaust gas recirculation flow rate.
Claims19
A method of selecting a firing pattern in a skip fire controlled internal combustion engine, the engine having an intake manifold and an exhaust system, comprising:
- determining a desired exhaust gas recirculation flow rate;
- determining a position of an exhaust gas recirculation valve;
- selecting the firing pattern based at least in part on the desired exhaust gas recirculation flow rate and the position of the exhaust gas recirculation valve;
- determining an engine speed;
- determining a firing fraction;
- determining a boost pressure in the intake manifold;
- and
- regulating a maximum exhaust gas recirculation rate based at least in part on the engine speed, the firing fraction, and the boost pressure.
A method of selecting a firing pattern in a skip fire controlled internal combustion engine, the engine having an intake manifold and an exhaust system, comprising:
- determining a desired exhaust gas recirculation flow rate;
- determining a position of an exhaust gas recirculation valve;
- and
- selecting a firing pattern based at least in part on the desired exhaust gas recirculation flow rate and the position of the exhaust gas recirculation valve, wherein the selected firing pattern has more engine-cycle-to-engine-cycle fluctuations in a number of cylinder firings venting into a second exhaust manifold than a number of cylinder firings venting into a first exhaust manifold.
A skip fire controlled, turbocharged, internal combustion engine, the engine having an intake manifold, an exhaust gas recirculation system, and an exhaust system having at least two exhaust manifolds, comprising:
- an exhaust gas recirculation feed line connected to the exhaust system, wherein the exhaust gas circulation feed line has a more direct fluid connection to a first exhaust manifold than to a second exhaust manifold;
- and
- an engine control system that includes non-transitory executable instructions stored in a memory to;
- determine a firing pattern based at least in part on a desired exhaust gas recirculation flow rate;
- determine an engine speed;
- determine a firing fraction;
- determine a boost pressure in the intake manifold;
- and
- regulate a maximum exhaust gas recirculation rate based at least in part on the engine speed, the firing fraction, and the boost pressure.
A skip fire controlled, turbocharged, internal combustion engine, the engine having an intake manifold, an exhaust gas recirculation system, and an exhaust system having at least two exhaust manifolds, comprising:
- an exhaust gas recirculation feed line connected to the exhaust system, wherein the exhaust gas circulation feed line has a more direct fluid connection to a first exhaust manifold than to a second exhaust manifold;
- and
- an engine control system that determines a firing pattern based at least in part on a desired exhaust gas recirculation flow rate, wherein the engine control system uses a first control algorithm to control a first firing pattern for cylinders that vent into the first exhaust manifold and a second control algorithm to control a second firing pattern for cylinders that vent into the second exhaust manifold.
Dependencies are inferred from the claim text.