Differential fueling between donor and non-donor cylinders in engines

A system comprising:

• an engine comprising:
• a donor cylinder group coupled to an intake manifold;
• wherein the take manifold is configured to feed a flow of air to the donor cylinder group;
• a non-donor cylinder group coupled to the intake manifold and an exhaust manifold;
• wherein the intake manifold is further configured to feed air to the non-donor cylinder group;
• a first direct injector disposed in each cylinder of the donor cylinder group configured to inject a first fuel from a first fuel source and a second port injector disposed in each of a plurality of first intake passages configured to inject a second fuel from a second fuel source;
• a third direct injector disposed in each cylinder of the non-donor cylinder group configured to inject the first fuel from the first fuel source and a fourth port injector disposed in each of a plurality of second intake passages for injecting the second fuel from the second fuel source;
• an exhaust channel extending from the donor cylinder group to the intake manifold for recirculating an exhaust emission from the at least one donor cylinder to the at least one donor, and non-donor cylinders via the intake manifold;
• and
• a controller configured to, during a single engine cycle, operate the first direct injector, the second port injector, the third injector and the fourth port injector such that there is a higher fraction of injection of the first fuel into the donor cylinder group in comparison to the first fuel being injected into the non-donor cylinder group and a lower fraction of injection of the second fuel into the donor cylinder group comparison to the second fuel being injected into the non-donor cylinder group.

A method of controlling an engine, comprising:

• injecting a first fuel and a second fuel to each of a donor cylinder soup anal a non-donor cylinder group of the engine;
• injecting a lower fraction of the first fuel into the nor cylinder group in comparison to the first fuel being injected into the non-donor cylinder group;
• injecting a higher fraction of the second fuel into the donor cylinder group in comparison to the second fuel being injected into the non-donor cylinder group;
• combusting a mixture of air, the first fuel, the second fuel in the donor cylinder group and the non-donor cylinder group and an exhaust emission from the donor cylinder group;
• operating the donor cylinder group, during low power or low temperature conditions, at an optimal first fuel injection timing so as to obtain higher substitution rate of the first fuel as compared to a substitution rate of the first fuel in the non-donor cylinder group causing generation of emissions from the donor cylinder group having increased amounts of carbon monoxide;
• and
• recirculating the exhaust emission from the donor cylinder group to the non-donor cylinder group and the donor cylinder group for oxidizing the increased amounts of carbon monoxide.