Patent ID: 7543631

Claim:
An exhaust gas heat exchanger for a cogeneration system comprising: a heat exchanger body provided with an exhaust gas inlet, through which exhaust gas discharged from an engine is introduced into the heat exchanger body, and an exhaust gas outlet, through which the exhaust gas is discharged from the heat exchanger body; a heat exchanger cover provided with a heat medium inlet through which a heat medium is introduced into the heat exchanger cover, and a heat medium outlet through which the heat medium inside the heat exchanger cover is discharged, and arranged to enclose the heat exchanger body such that a primary heat medium passage, through which a heat medium passes, is defined between an outer wall surface of the heat exchanger body and an inner wall surface of the heat exchanger cover; and a heat medium tube arranged to extend through the heat exchanger body, and adapted to form a secondary heat medium passage, through which the heat medium emerging from the primary heat medium passage passes, wherein the heat medium tube comprises: a heat medium inlet tube extending through the heat exchanger body and being connected with the heat medium outlet formed at the heat exchanger cover; a heat medium outlet tube extending through the heat exchanger body at a position different from a position of the heat medium inlet tube; and a plurality of connecting tubes each arranged in the heat exchanger body, and connected with the heat medium inlet tube and the heat medium outlet tube.