Abstract: A method is provided for operating an Exhaust Gas Recirculation (EGR) system of a thermal energy source, the EGR system includes, but is not limited to an EGR circuit and an EGR cooler, the EGR cooler connected in a heat exchanging relationship with an EGR coolant circuit equipped with an EGR coolant pump. The method includes, but is not limited to monitoring a parameter (TEGRcool) representative of a temperature of the coolant in the EGR coolant circuit, operating the EGR coolant pump on the basis of the parameter (TEGRcool) and of a target value thereof (TEGRtgt).

Abstract: The present invention, provides a strategy or method for injecting fuel in two distinct fuel injection events per engine cycle. The first injection event is main fuel injection, which occurs when the crankshaft is near top-dead center. The main injection event delivers a majority of the fuel needed to provide a majority of the power produced during combustion. The second injection event is post injection, which occurs shortly after the main fuel injection event. The post injection event provides a supplemental amount of fuel to the combustion chamber to reduce the rate of pressure rise while increasing, turbulence, mixing and cylinder pressure within the combustion chamber to reduce the formation of soot. In addition, the combination of the main fuel injection event and the post fuel injection event reduces engine noise by reducing heat release rates and the rate of combustion chamber pressurization.