Heat exchanger with integrated co-axial inlet/outlet tube

A manifold insert for of a heat exchanger, comprising:

• an elongated cylindrical body defining an open interior passage;
• a first end for sealingly engaging a portion of an interior of a manifold of the heat exchanger and defining an annular first manifold flow passage between the outer surface of said cylindrical body and the interior surface of said manifold, the first manifold flow passage being fluidly coupled to a first set of heat exchanger fluid channels;
• a second end extending out of said manifold for receiving a fluid fitting;
• and
• a second manifold flow passage defined by said open interior passage, the second manifold passage being fluidly coupled to a second set of said heat exchanger fluid channels;
• wherein said manifold insert divides said heat exchanger into a first part corresponding to said first set of heat exchanger fluid channels and a second part corresponding to said second set of heat exchanger fluid channels, the first and second parts defining a two-pass flow path;
• wherein said manifold insert has a first end disposed within a recessed area of a boss portion of a heat exchanger plate that forms said heat exchanger and defines a corresponding one of the heat exchanger fluid channels, the first end defining a sealing surface for closing an end of the annular manifold flow passage thereby preventing fluid communication between the annular manifold fluid passage and an adjacent one of the heat exchanger fluid channels, the first sealing end being recessed within the boss portion leaving the corresponding one of the heat exchanger fluid channels unobstructed.

A method of forming a two-pass heat exchanger comprising:

• providing a heat exchanger core comprising:
• a plurality of spaced apart heat exchanger plates defining a plurality of alternating first and second fluid channels therebetween, wherein each heat exchanger plate comprises a base portion;
• a peripheral wall extending from and surrounding the base portion, the peripheral wall of one heat exchanger plate sealing against the peripheral wall of the adjacent heat exchanger plate when said plates are stacked together in a nesting relationship;
• a pair of boss portions that project out of the plane of the base portion, each boss portion having a fluid opening formed therein;
• and a pair of fluid openings formed in the plane of the base portion;
• wherein the fluid openings in each of the boss portions of one plate align and mate with the fluid openings formed in the plane of the base portion of the adjacent plate, the boss portions spacing apart the adjacent plates;
• a pair of first fluid manifolds in communication with said plurality of first fluid channels for directing a first fluid through said heat exchanger;
• a pair of second fluid manifolds in communication with said second fluid channels for directing a second fluid through said heat exchanger;
• providing a manifold insert having an elongated, cylindrical body extending between first and second ends, the manifold insert having a diameter less than the diameter of at least one of said manifolds in one of said pairs of manifolds;
• arranging said manifold insert within the at least one of said manifolds, the first end of said manifold insert being recessed within a boss portion of a heat exchanger plate defining a corresponding fluid channel, the boss portion forming part of said manifold of said heat exchanger, the first end defining a sealing surface thereby dividing the heat exchanger core into a first part and a second part, the second end of the manifold insert extending outwardly from the heat exchanger core;
• wherein the manifold insert defines an annular first manifold fluid passage between the at least one of said manifolds and the outer surface of said manifold insert, and a second manifold fluid passage within the open interior passage formed by the cylindrical body, the annular first manifold fluid passage being in fluid communication with the one of said plurality of first or second fluid channels in said first part, and wherein the second manifold fluid passage is in fluid communication with the one of said plurality of first or second fluid channels in said second part;
• wherein said first end of said manifold insert disposed within the recessed area of said boss portion of a heat exchanger plate that forms said heat exchanger and defines a corresponding one of the heat exchanger fluid channels defines a sealing surface for closing an end of the annular manifold flow passage thereby preventing fluid communication between the annular manifold fluid passage and an adjacent one of the heat exchanger fluid channels, the first sealing end being recessed within the boss portion thereby leaving the corresponding one of the heat exchanger fluid channels unobstructed.