Turbo-charged internal combustion engine with in-cylinder EGR and injection rate shaping
A turbo-charged internal combustion cylinder assembly includes a combustion chamber which may be communicably connected to a compressor via an intake port through an intake manifold and aftercooler so the compressor may provide pre-combustion gases to the combustion chamber when the intake valve is open. An exhaust port communicably connects the combustion chamber to an exhaust manifold. An exhaust valve may open to exhaust post-combustion gases to the exhaust manifold while an intake valve is substantially closed, and the exhaust valve may open to admit post-combustion gases to the combustion chamber while the intake valve is substantially open and an exhaust port pressure in the exhaust port is higher than a combustion chamber pressure in the combustion chamber. A fuel injector may admit fuel to the combustion chamber. A spill valve may control a rate of fuel injection to the combustion chamber, the spill valve having a first position providing a maximum fuel injection rate, a second position providing a substantially zero fuel injection rate, and at least one intermediate position providing an intermediate fuel injection rate between the maximum fuel injection rate and the zero fuel injection rate.
1. A method of controlling combustion in an internal combustion engine comprising the steps of:
transferring a first quantity of fuel and first post-combustion gases to a combustion chamber through an exhaust port to raise a temperature of said first quantity of fuel while an exhaust port pressure in said exhaust port is higher than a first combustion chamber pressure;
transferring pre-combustion gases into said combustion chamber at said first combustion chamber pressure;
mixing said first quantity of fuel, said pre-combustion gases, and said first post-combustion gases to form a substantially homogenous mixture;
substantially sealing said exhaust port from said combustion chamber;
adding heat to said combustion chamber by raising said first combustion chamber pressure to a second combustion chamber pressure substantially higher than said first combustion chamber pressure;
transferring a second quantity of fuel to said combustion chamber,
substantially combusting said first and second quantities of fuel with said heat to form second post-combustion gases;
exhausting said second post-combustion gases through said exhaust port.
2. The method of controlling combustion in an internal combustion engine of claim 1 , wherein the step of transferring said first quantity of fuel and first post-combustion gases to said combustion chamber comprises further the step of injecting said first quantity of fuel into said exhaust port or exhaust manifold.
3. The method of controlling combustion in an internal combustion engine of claim 1 , wherein the step of injecting said second quantity of fuel further comprises the step of shaping a rate of said fuel injection.
4. The method controlling combustion in an internal combustion engine of claim 1 , wherein the step of substantially combusting said first and second quantities of fuel with said heat to form second post-combustion gases comprises further the steps of:
injecting a third quantity of fuel into said combustion chamber;
substantially combusting said third quantity of fuel with said heat.
5. The method controlling combustion in an internal combustion engine of claim 4 , wherein the step of injecting said third quantity of fuel comprises further the step of shaping a rare said fuel injection.