| 摘要 |
The invention relates to an exhaust-gas heat exchanger for an exhaust system for cooling an exhaust-gas flow, having an inner pipe (2) and an outer pipe (3), wherein the two pipes (2, 3) are indirectly or directly welded to one another in sealing fashion at the inlet side, a jacket pipe (3.1) is arranged around the outside of the outer pipe (3) and an annular gap (5) for coolant is arranged between the outer pipe (3) and the jacket pipe (3.1), and the inner pipe (2) has an axial flow cross section (A2) at the end as viewed in the flow direction (S) and has a perforation (P2), which forms a radial flow cross section, in a direction at right angles to a flow direction (S). Between the inner pipe (2) and the outer pipe (3) there is formed an exhaust-gas duct (6) for the exhaust-gas flow, wherein an intermediate pipe (4) which is mounted in displaceable and/or rotatable fashion on the inner pipe (2) is provided with a perforation (P4) by means of which the axial flow cross section (A2) of the inner pipe (2) can be at least partially closed off. |
