Method to enhance the performance of a heavy-duty diesel-H2 dual-fuel engine through engine system optimization

1. A hydrogen-diesel dual-fuel engine, comprising:

an engine block, comprising;

a cylinder, wherein the cylinder is outfitted with at least two hydrogen fuel injectors; and

a piston, wherein the piston is enclosed by the cylinder and wherein the piston comprises a piston crown;

an air-handling system, comprising:

an intake manifold;

an intake pipe, wherein the intake pipe receives air through an air inlet and carries the air to the intake manifold;

an exhaust pipe, wherein the exhaust pipe receives exhaust gases and expels, at least a portion, of the exhaust gases;

a variable geometry turbocharger coupled to the intake pipe and the exhaust pipe; and

an exhaust gas recirculation system configured to recirculate exhaust gases from the exhaust pipe to the intake manifold;

a two-step camshaft, wherein the two-step camshaft is configured with the air-handling system for exhaust re-breathing and late intake valve closing;

a port fuel injector system directly integrated with the intake manifold, wherein the port fuel injector system provides hydrogen gas to the at least two hydrogen fuel injectors;

a diesel injector configured to inject diesel into the cylinder;

a common-rail fuel injection system configured to supply diesel to the diesel injector;

a plurality of sensors, comprising:

a temperature sensor, and

a tachometer; and

a controller configured to receive engine data from the plurality of sensors and to control operation of the hydrogen-diesel dual-fuel engine,

wherein the controller is configured to collectively operate the two-step camshaft, exhaust gas recirculation system, and variable geometry turbocharger to maintain the production of NOx below 2 g/kWh.

2. The hydrogen-diesel dual-fuel engine of claim 1 , wherein the air-handling system further comprises:

a charge air cooler;

an idle air control valve;

an exhaust back pressure valve;

an exhaust gas recirculation valve; and

an exhaust gas recirculation cooler.

3. The hydrogen-diesel dual-fuel engine of claim 1 , further comprising:

a spark ignitor, wherein the spark ignitor is configured to generate a spark in the cylinder.

4. The hydrogen-diesel dual-fuel engine of claim 1 , wherein the controller determines an operational load of the hydrogen-diesel dual-fuel engine based on the engine data.

5. The hydrogen-diesel dual-fuel engine of claim 4 ,

wherein under a low operational load the controller is configured to adjust the two-step camshaft to use exhaust gas re-breathing and to not use late intake valve closing,

wherein under a moderate operational load the controller is configured to adjust the two-step camshaft to not use exhaust gas re-breathing and to not use late intake valve closing, and

wherein under a high operational load the controller is configured to adjust the two-step camshaft to not use exhaust gas re-breathing and to use late intake valve closing.

6. The hydrogen-diesel dual-fuel engine of claim 1 ,

wherein the piston crown comprises a substantially annular piston bowl defined by a conical center and a bowl wall;

wherein the bowl wall contains a convex radius, and

wherein the convex radius partitions a volume of the piston bowl into a periphery region and a central region.

7. The hydrogen-diesel dual-fuel engine of claim 1 , wherein the diesel injector has at least 12 nozzles.