EGR cooling system

A method of cooling recirculating exhaust gas via an exhaust gas cooler, the method comprising:

• causing exhaust gas to flow into an inlet manifold positioned at a first end of the exhaust gas cooler and out of an outlet manifold positioned at a second end of the exhaust gas cooler, the exhaust gas transmitted from the inlet manifold to the outlet manifold via a plurality of conduits coupled to the inlet manifold and the outlet manifold, each conduit in the plurality of conduits extending from an exhaust gas inlet opening of the plurality of exhaust gas inlet openings in the inlet manifold to an exhaust gas outlet opening of the plurality of exhaust gas outlet openings in the outlet manifold;
• causing coolant to flow into a region between at least one side wall coupled to the outlet manifold and the inlet manifold around the plurality of conduits, the coolant flowing into the region via a first coolant inlet opening in the at least one side wall, the first coolant inlet opening adjacent the first end of the exhaust gas cooler;
• causing at least a portion of the coolant to flow out of the region via a first coolant outlet opening adjacent the first end of the exhaust gas cooler;
• causing the at least a portion of the coolant to flow back into the region via a bypass conduit fluidly coupling the first coolant outlet opening to a second coolant inlet opening in the at least one side wall;
• and
• causing the coolant to flow out of the region via a second coolant outlet opening in the at least one side wall,
• whereby heat is convectively transferred from exhaust gas flowing through the plurality of conduits to coolant flowing through the region.

An engine system for cooling recirculating exhaust gas, the engine system comprising:

• an engine;
• an exhaust manifold configured to receive exhaust from at least one cylinder of the engine;
• an exhaust gas cooler including:
• an inlet manifold positioned at a first end of the exhaust gas cooler, the inlet manifold including a plurality of exhaust gas inlet openings;
• an outlet manifold positioned at a second end of the exhaust gas cooler, the outlet manifold including a plurality of exhaust gas outlet openings;
• a plurality of conduits coupled to the inlet manifold and the outlet manifold, each conduit in the plurality of conduits extending from an exhaust gas inlet opening of the plurality of exhaust gas inlet openings to an exhaust gas outlet opening of the plurality of exhaust gas outlet openings;
• at least one side wall coupled to the outlet manifold and the inlet manifold around the plurality of conduits such that the plurality of conduits are disposed in a region between the at least one side wall, the inlet manifold and the outlet manifold, the at least one sidewall including:
• a first coolant inlet opening adjacent the first end of the exhaust gas cooler,
• a first coolant outlet opening adjacent the first end of the exhaust gas cooler,
• a second coolant inlet opening, and
• a second coolant outlet opening;
• and
• a bypass conduit positioned outside of the region, the bypass conduit fluidly coupling the first coolant outlet opening to the second coolant inlet opening, such that at least a part of a coolant flowing into the region adjacent the first end of the exhaust gas cooler and between the plurality of conduits flows out of the region adjacent the first end via the first coolant outlet opening, through the bypass conduit, and back into the region via the second coolant inlet opening;
• and
• an intake manifold configured to provide intake air into the at least one cylinder,
• wherein the exhaust gas cooler is coupled to the exhaust manifold via the inlet manifold of the exhaust gas cooler and wherein exhaust gas cooler is coupled to the intake manifold via the outlet manifold of the exhaust gas cooler.

An exhaust gas cooler for cooling recirculating exhaust gas, the exhaust gas cooler comprising:

• exhaust gas flow means for causing exhaust gas to flow into an inlet manifold at a first end of the exhaust gas cooler and out of an outlet manifold at a second end of the exhaust gas cooler, the exhaust gas flow means further configured for transmitting the exhaust gas from the inlet manifold to the outlet manifold in a plurality of distinct flow paths;
• at least one side wall coupled to the outlet manifold and the inlet manifold about the plurality of distinct flow paths;
• coolant flow entry means for causing coolant to flow into a region within the at least one side wall adjacent the first end of the exhaust gas cooler;
• bypass means for causing at least a portion of the coolant to flow out of the region adjacent the first end of the exhaust gas cooler and for causing the at least a portion of the coolant to flow back into the region;
• and
• coolant flow exit means for causing the coolant to flow out of the region,
• whereby heat is convectively transferred from exhaust gas in the plurality of distinct flow paths to coolant flowing into and out of the region.