Abstract: A heat exchanger with a plurality of stacked flat tubes and a collecting tank having a wall extending around the entire periphery of, and connected to, the end of the stacked flat tubes. A first medium may be distributed through the collecting tank and flat tubes. Internal inserts are in the flat tubes, with the inserts being bonded between the broad sides of the tubes and, in the region of connection of the tubes to the collecting tank, being configured to compensate for length changes in the stacking direction caused by temperature changes, as by recesses in connectors such as wave flanks or by corrugated wave flanks. The flat tubes with inserts such as described may be separately provided for use in manufacture of heat exchangers.

Abstract: The invention relates to an exhaust gas heat exchanger in an exhaust gas recirculation arrangement. The heat exchanger includes a plate stack which is surrounded by a housing. The plate stack can include two plates which are connected at their longitudinal edges to form a flat tube which contains a turbulator through which exhaust gas flows. The heat exchanger can also include a coolant duct which is equipped with flow directing elements arranged between two flat tubes. In order to make the exhaust gas heat exchanger more resistant to changing temperature stresses, the invention provides that the flow directing elements can be formed from a corrugated plate in which ducts with inlets and outlets are formed. At least some of the ducts in the inlet area of the coolant have a nonlinear profile so that changes in length are permitted between the plate stack and the housing.

Abstract: The present invention relates to a heat exchanger, in particular, an oil cooler for motor vehicles, constructed from trough-shaped heat exchanger plates which are stacked into one another and from turbulence inserts, having two openings for one medium and two further openings for another medium in order to form collecting ducts for the supply and discharge of the media, with flow ducts for the media being formed between the heat exchanger plates. The heat exchanger also includes flow ducts connected to the associated collecting ducts, an upper closure plate which has convexities in the region of the collecting tanks, and an intermediate plate which is provided with holes. The intermediate plate is arranged between the closure plate and the uppermost heat exchanger plate, and one of the holes, formed as a pressure equalizing opening, interacts with the upwardly aligned convexity in the closure plate to improve the internal pressure stability.

Abstract: The invention relates to an exhaust gas heat exchanger in an exhaust gas recirculation arrangement. The heat exchanger includes a plate stack which is surrounded by a housing. The plate stack can include two plates which are connected at their longitudinal edges to form a flat tube which contains a turbulator through which exhaust gas flows. The heat exchanger can also include a coolant duct which is equipped with flow directing elements arranged between two flat tubes. In order to make the exhaust gas heat exchanger more resistant to changing temperature stresses, the invention provides that the flow directing elements can be formed from a corrugated plate in which ducts with inlets and outlets are formed. At least some of the ducts in the inlet area of the coolant have a nonlinear profile so that changes in length are permitted between the plate stack and the housing.

Abstract: A vaporizer, a fuel cell system including the vaporizer, and a method of vaporizing fuel in a fuel cell system are disclosed. The fuel cell system includes a fuel reservoir (24) for storing a liquid fuel and a fuel cell (10) for consuming a fuel and generating electricity therefrom. A fuel vaporizer (28) is interposed between the fuel reservoir (24) and the fuel cell (10) for receiving liquid fuel and vaporizing it and delivering it ultimately to the fuel cell (10). The fuel vaporizer (28) includes a heat exchanger which includes a hot fluid inlet (65), a hot fluid outlet (67) and a core (50) interconnecting the inlet (65) and the outlet (68). The core (50) has alternating fuel flow structures (68) and hot fluid structures (69) with the fuel flow structures (68,69) having an inlet (56) and an outlet (58).

Abstract: A heat exchanger with a plurality of stacked flat tubes and a collecting tank having a wall extending around the entire periphery of, and connected to, the end of the stacked flat tubes. A first medium may be distributed through the collecting tank and flat tubes. Internal inserts are in the flat tubes, with the inserts being bonded between the broad sides of the tubes and, in the region of connection of the tubes to the collecting tank, being configured to compensate for length changes in the stacking direction caused by temperature changes, as by recesses in connectors such as wave flanks or by corrugated wave flanks. The flat tubes with inserts such as described may be separately provided for use in manufacture of heat exchangers.

Abstract: A vaporizer, a fuel cell system including the vaporizer, and a method of vaporizing fuel in a fuel cell system are disclosed. The fuel cell system includes a fuel reservoir (24) for storing a liquid fuel and a fuel cell (10) for consuming a fuel and generating electricity therefrom. A fuel vaporizer (28) is interposed between the fuel reservoir (24) and the fuel cell (10) for receiving liquid fuel and vaporizing it and delivering it ultimately to the fuel cell (10). The fuel vaporizer (28) includes a heat exchanger which includes a hot fluid inlet (65), a hot fluid outlet (67) and a core (50) interconnecting the inlet (65) and the outlet (68). The core (50) has alternating fuel flow structures (68) and hot fluid structures (69) with the fuel flow structures (68,69) having an inlet (56) and an outlet (58).