Exhaust heat exchanger

An exhaust heat exchanger, comprising:

• tubes held in tube sheets at both ends for guiding a gaseous medium and defining a tube bundle,
• a housing adjoining the tube sheets and surrounding the tubes for guiding a liquid coolant, the tube sheets, the tubes, and the housing being made from heat-resistant austenitic steel sheet, the tubes being welded into the tube sheets, and the housing being welded to the tube sheets, the tube sheets being deep-drawn stamped parts,
• a circumferential wall included in each of said stamped parts that projects outward beyond ends of the tubes of the tube bundle, and
• a diffuser abutted by each circumferential wall, each circumferential wall being welded to said housing,
• wherein the housing, adjacent to said tube sheets, has areas with cross sections that are larger than a cross section in the area located therebetween in which the housing surrounds the tubes of said tube bundle with a small distance between them, and
• wherein the housing is assembled from at least two shaped sheet-metal parts and is welded by welded seams that extend parallel to the tubes of said tube bundle.

An exhaust heat exchanger, comprising:

• tubes held in tube sheets at both ends for guiding a gaseous medium and defining a tube bundle,
• a housing adjoining the tube sheets and surrounding the tubes for guiding a liquid coolant, the tube sheets, the tubes, and the housing being made from heat-resistant austenitic steel sheet, the tubes being welded into the tube sheets, and the housing being welded to the tube sheets, the tube sheets being deep-drawn stamped parts,
• a circumferential wall included in each of said stamped parts that projects outward beyond ends of the tubes of the tube bundle, and
• a diffuser abutted by each circumferential wall, each circumferential wall being welded to said housing,
• wherein said housing is provided, in a first area with a larger cross section, with a connecting tube for a coolant inlet and, in a second area with a larger cross section, with a connecting tube for a coolant drain, and
• wherein said housing is provided with outwardly directed beams to which said connecting tubes are welded.

Heat exchanger comprising:

• a tube bundle, having opposite ends, which guides a gaseous medium,
• tube sheets holding said opposite ends of said tube bundle,
• a housing surrounding the tube bundle and guiding a liquid coolant,
• circumferential walls included in said tube sheets that project outward beyond ends of the tube bundle, and
• diffusers abutting the circumferential walls,
• wherein the circumferential walls are welded to said housing,
• wherein the housing, adjacent to said tube sheets, has areas with cross sections that are larger than a cross section in the area located therebetween in which the housing surrounds the bundle, and
• wherein the housing is assembled from at least two shaped sheet-metal parts and is welded by welded seams that extend parallel to the tube bundle.