Efficient heat exchanger and engine using same

A heat exchanger comprising:

• a housing having an annular internal wall that defines a portion of a heat exchanging cavity;
• a tube bundle positioned in said housing and including a plurality of tubes and a plurality of baffles;
• said internal wall and said tube bundle defining a serpentine flow path that includes a plurality of flow direction changing windows;
• said plurality of tubes including a perimeter set of tubes that define a bundle perimeter that is separated from said internal wall by a window distance at said windows, and separated by a gap distance away from said windows;
• said window distance is greater than said gap distance;
• and
• said gap distance is uniform for a segment of said bundle perimeter corresponding to a plurality of adjacent tubes of said perimeter set of tubes.

A heat exchanger comprising:

• a housing having an annular internal wall that defines a portion of a heat exchanging cavity;
• a tube bundle positioned in said housing and including a plurality of tubes and a plurality of baffles;
• said internal wall and said tube bundle defining a serpentine flow path that includes a plurality of flow direction changing windows;
• said plurality of tubes including a perimeter set of tubes that define a bundle perimeter that is separated from said internal wall by a window distance at said windows, and separated by a gap distance away from said windows;
• said window distance is greater than said gap distance;
• and
• said window distance is uniform for a segment of said bundle perimeter corresponding to a plurality of adjacent tubes of said perimeter set of tubes.

A heat exchanger comprising:

• a housing having an annular internal wall that defines a portion of a heat exchanging cavity;
• a tube bundle positioned in said housing and including a plurality of tubes and a plurality of baffles;
• said internal wall and said tube bundle defining a serpentine flow path that includes a plurality of flow direction changing windows;
• said plurality of tubes including a perimeter set of tubes that define a bundle perimeter that is separated from said internal wall by a window distance at said windows, and separated by a gap distance away from said windows;
• said window distance is greater than said gap distance;
• and
• said bundle perimeter has a hexagonal shape.

A heat exchanger comprising:

• a housing having an annular internal wall that defines a portion of a heat exchanging cavity;
• a tube bundle positioned in said housing and including a plurality of tubes and a plurality of baffles;
• said internal wall and said tube bundle defining a serpentine flow path that includes a plurality of flow direction changing windows;
• said plurality of tubes including a perimeter set of tubes that define a bundle perimeter that is separated from said internal wall by a window distance at said windows, and separated by a gap distance away from said windows;
• said window distance is greater than said gap distance;
• and
• said housing is one-piece, homogenous and includes one of aluminum and iron;
• and
• said tubes are identical lengths of copper tubing.

A heat exchanger comprising:

• a housing having an annular internal wall that defines a portion of a heat exchanging cavity;
• a tube bundle positioned in said housing and including a plurality of tubes and a plurality of baffles;
• said internal wall and said tube bundle defining a serpentine flow path that includes a plurality of flow direction changing windows;
• said plurality of tubes including a perimeter set of tubes that define a bundle perimeter that is separated from said internal wall by a window distance at said windows, and separated by a gap distance away from said windows;
• said window distance is greater than said gap distance;
• and
• said internal wall includes a pair of planar wall segments that are parallel to one another;
• and
• said windows are partially defined by said planar wall segments.

A heat exchanger comprising:

• a housing having an annular internal wall that defines a portion of a heat exchanging cavity;
• a tube bundle positioned in said housing and including a plurality of tubes and a plurality of baffles;
• said internal wall and said tube bundle defining a serpentine flow path that includes a plurality of flow direction changing windows;
• said plurality of tubes including a perimeter set of tubes that define a bundle perimeter that is separated from said internal wall by a window distance at said windows, and separated by a gap distance away from said windows;
• said window distance is greater than said gap distance;
• and
• said windows have a window width that is greater than said cavity height.

A heat exchanger comprising:

• a housing having an annular internal wall that defines a portion of a heat exchanging cavity;
• a tube bundle positioned in said housing and including a plurality of tubes and a plurality of baffles;
• said internal wall and said tube bundle defining a serpentine flow path that includes a plurality of flow direction changing windows;
• said plurality of tubes including a perimeter set of tubes that define a bundle perimeter that is separated from said internal wall by a window distance at said windows, and separated by a gap distance away from said windows;
• said window distance is greater than said gap distance;
• and
• said tube bundle includes an odd number of tube rows sequentially arranged along a height dimension;
• and
• one of said tube rows is longer than all other ones of said tube rows.