Patent ID: 8020610

Claim:
An exhaust gas heat exchanger in an exhaust gas recirculation arrangement, the heat exchanger comprising: a housing; and a stack at least partially surrounded by the housing and including flat tubes containing a turbulator through which exhaust gas flows and a coolant duct having a flow directing element arranged between two of the flat tubes and formed from a corrugated plate, wherein the corrugated plate includes a non-linear corrugation having bent walls defining a first duct in the coolant duct, the first duct having an inlet and an outlet, wherein the corrugation is nonlinear having bent walls so that the first duct includes a nonlinear profile between the inlet and the outlet and the first duct defines a first path segment extending in a transverse direction of the heat exchanger and a second path segment extending in a longitudinal direction of the heat exchanger, wherein changes in length are permitted between the stack and the housing; wherein the corrugation further defines a second duct in the cooling duct, wherein the second duct includes an inlet and an outlet and a nonlinear profile between the inlet of the second duct and the outlet of the second duct and the second duct defines a first path segment extending in the transverse direction of the heat exchanger and a second path segment extending in the longitudinal direction of the heat exchanger; wherein a coolant flow direction in the first path segment of the second duct is opposite a coolant flow direction in the first path segment of the first duct.