Abstract: An exhaust gas heat recovery (EGHR) heat exchanger, for recovering waste heat from the hot exhaust gases of an internal combustion engine, having a housing and a cylindrical body disposed within the housing. The cylindrical body defines a central passageway and together with the housing defines an annular passageway for the flow of hot exhaust gases. A bypass means is disposed within the central passageway and adapted to selectively by-pass at least a portion of the exhaust gas from the central passageway to the annular passageway. The EGHR heat exchanger also includes at least one fluid tube extending along a tube axis and having at least one lobe extending the length of the tube thereby defining a lobed tube. The lobed tube is twisted about the tube axis forming a twisted lobed tube which is then coiled about the longitudinal axis within the annular exhaust gas passageway.

Abstract: An exhaust gas heat recovery (EGHR) heat exchanger, for recovering waste heat from the hot exhaust gases of an internal combustion engine, having a housing and a cylindrical body disposed within the housing. The cylindrical body defines a central passageway and together with the housing defines an annular passageway for the flow of hot exhaust gases. A bypass means is disposed within the central passageway and adapted to selectively by-pass at least a portion of the exhaust gas from the central passageway to the annular passageway. The EGHR heat exchanger also includes at least one fluid tube extending along a tube axis and having at least one lobe extending the length of the tube thereby defining a lobed tube. The lobed tube is twisted about the tube axis forming a twisted lobed tube which is then coiled about the longitudinal axis within the annular exhaust gas passageway.

Abstract: An exhaust gas heat recovery (EGHR) heat exchanger for an internal combustion engine having a housing, a cylindrical body disposed within the housing, an annular exhaust gas passageway, and a central exhaust gas passageway. The EGHR heat exchanger also includes a bypass valve disposed within the central passageway and adapted to selectively by-pass a portion of the exhaust gas from the central exhaust gas passageway to the annular passageway, and at least one twisted tube having at least one edge coiled within the annular exhaust gas passageway.