A heat exchanger includes: a stack formed by stacking a plurality of tubes through which gas flow; a tubular inner tank in which the stack is housed; and a tubular outer tank that is mounted on the outside of the inner tank so as to define an inner space between the outer tank and an outer peripheral surface of the inner tank. Each of both end portions of the tubes has a thickness greater than each of middle portions of the tubes. The both end portions of the tubes adjacent to each other in the stack are joined together so as to form a clearance between the middle portions of the adjacent tubes in the stack. Outer peripheries of both end portions of the stack are joined to an inner peripheral surface of the inner tank. An introduction hole for introducing a cooling medium is formed in the outer tank.

A heat exchanger includes: a stack formed by stacking a plurality of tubes through which gas flow; a tubular inner tank in which the stack is housed; and a tubular outer tank that is mounted on the outside of the inner tank so as to define an inner space between the outer tank and an outer peripheral surface of the inner tank. Each of both end portions of the tubes has a thickness greater than each of middle portions of the tubes. The both end portions of the tubes adjacent to each other in the stack are joined together so as to form a clearance between the middle portions of the adjacent tubes in the stack. Outer peripheries of both end portions of the stack are joined to an inner peripheral surface of the inner tank. An introduction hole for introducing a cooling medium is formed in the outer tank.

An EGR cooler includes a tube assembly formed by stacking a plurality of tubes in which exhaust gas flows and a cover plate having a mounting portion formed concavely to mount the tube assembly thereon. A baffle is mounted at the tube assembly and adjusts flow of coolant inflow from a cylinder block. An inlet cover is installed on a first side of an outer surface of the cover plate to supply the exhaust gas to each tube and an outlet cover is installed on a second side of outer surface of the cover plate to exhaust the exhaust gas from each tube. At least one coolant passage in which the coolant flows is formed between the plurality of tubes.

An EGR cooler may include an EGR cooler housing having top, bottom and side walls, inlet and outlet end walls disposed at opposite ends, and a longitudinal axis extending in a direction of exhaust gas flow from the inlet end to the outlet end. A plurality of cooling tubes extend through the EGR cooler between the top and bottom walls, and are arranged in a cooling tube array to form an exhaust gas receiving area at an upstream side of the cooling tube array proximate the inlet end wall so that exhaust gas flowing into the EGR cooler through an exhaust gas inlet opening will flow into the exhaust gas receiving area and then disperse through the cooling tube array. A pitch distance between the cooling tubes may be greater proximate the longitudinal axis than proximate the side walls to promote flow through, instead of around, the cooling tube array.

An EGR cooler may include an EGR cooler housing having top, bottom and side walls, inlet and outlet end walls disposed at opposite ends, and a longitudinal axis extending in a direction of exhaust gas flow from the inlet end to the outlet end. A plurality of cooling tubes extend through the EGR cooler between the top and bottom walls, and are arranged in a cooling tube array to form an exhaust gas receiving area at an upstream side of the cooling tube array proximate the inlet end wall so that exhaust gas flowing into the EGR cooler through an exhaust gas inlet opening will flow into the exhaust gas receiving area and then disperse through the cooling tube array. A pitch distance between the cooling tubes may be greater proximate the longitudinal axis than proximate the side walls to promote flow through, instead of around, the cooling tube array.

The invention relates to an heat exchanger possibly for exchanging heat within a vehicle. The heat exchanger includes a housing with an inlet port, an outlet port, an interior facing surface defining a coolant channel, a first opening surrounded by an exterior facing surface, and a second opening defined by a first inner diameter. A tube assembly defines a plurality of exhaust gas flow channels and a plurality of coolant cross channels within the housing. A first diffuser directs a first fluid into the tube assembly. The first diffuser is joined to the exterior facing surface, and this joint is sealed. A cap surface of the first diffuser encloses the first opening and caps the coolant channel. The first diffuser is joined to a first header plate, which separates the first fluid from a second fluid within the coolant channel. A second diffuser defines a directs the first fluid out of the tube assembly. The second diffuser is located within the second opening and sealed to the second opening by seals around the second diffuser. The second diffuser is not fixedly attached to the housing and can move within the second opening.

A heat exchanger disposed in an exhaust heat recovery device exchanges heat between exhaust and cooling fluid. An inner shell of the heat exchanger externally surrounds an exhaust pipe and forms a heat exchange space between the inner shell and the exhaust pipe to accommodate arranged plates. An outer shell of the heat exchanger includes an EGR opening that leads the exhaust to an inlet system of an internal combustion engine. The outer shell forms an external space leading to the EGR opening between the outer shell and the inner shell. The inner shell includes at least one aperture area that communicates the heat exchange space with the external space.

A heat exchanger disposed in an exhaust heat recovery device exchanges heat between exhaust and cooling fluid. An inner shell of the heat exchanger externally surrounds an exhaust pipe and forms a heat exchange space between the inner shell and the exhaust pipe to accommodate arranged plates. An outer shell of the heat exchanger includes an EGR opening that leads the exhaust to an inlet system of an internal combustion engine. The outer shell forms an external space leading to the EGR opening between the outer shell and the inner shell. The inner shell includes at least one aperture area that communicates the heat exchange space with the external space.

Various methods and systems are provided for an exhaust gas recirculation cooler including a plurality of cooling tubes. In one example, an exhaust gas recirculation (EGR) cooler includes a plurality of cooling tubes positioned within a housing of the EGR cooler, each cooling tube of the plurality of cooling tubes extending between and directly coupled to tube sheets of the EGR cooler at ends of each cooling tube, where at least one end of one or more cooling tubes of a first portion of the plurality of cooling tubes, inward of a tube sheet coupled to the at least one end, includes a compliant region, where the first portion is positioned proximate to an exhaust inlet of the EGR cooler.

Various methods and systems are provided for an exhaust gas recirculation cooler including a plurality of cooling tubes. In one example, an exhaust gas recirculation (EGR) cooler includes a plurality of cooling tubes positioned within a housing of the EGR cooler, each cooling tube of the plurality of cooling tubes extending between and directly coupled to tube sheets of the EGR cooler at ends of each cooling tube, where at least one end of one or more cooling tubes of a first portion of the plurality of cooling tubes, inward of a tube sheet coupled to the at least one end, includes a compliant region, where the first portion is positioned proximate to an exhaust inlet of the EGR cooler.