Stacked-tube heat exchanger
AssigneeDana Canada Corporation
InventorsMichael Martin, Alan Wu
Life of this patent
Estimating the term…
Abstract
A headerless heat exchanger has a core comprised of a stack of flat tubes of rectangular cross section through which a first heat exchange fluid passes. The tubes are expanded in height at their end portions to provide spaces between adjacent plate pairs for passage of a second heat exchange fluid between the tubes. The sides of the tubes are coplanar, at least in the end portions of the tubes, to provide flat surfaces along which the core is sealed to side plates of the heat exchanger, for example by brazing or welding. The side plates may be separately formed or may comprise part of a continuous housing. The tubes are preferably formed from plate pairs having nesting side walls.
Claims31
A heat exchanger for heat transfer between a first fluid and a second fluid, the heat exchanger comprising:
- (a) a core comprising a stack of tubes, each of the tubes having a top wall, a bottom wall, side walls connecting the top and bottom walls, a hollow interior enclosed by the top, bottom and side walls, and inlet and outlet openings for the first fluid;
- wherein each of the tubes has a pair of end portions spaced apart along a longitudinal axis and a central portion located between the end portions, the end portions of adjacent tubes in the core being sealed to one another along their top and bottom walls, wherein the end portions are greater in height than the central portions of the tubes such that the central portions of adjacent tubes in the core are spaced from one another;
- (b) a plurality of first fluid flow passages, each of which comprises the hollow interior of one of the tubes and extends longitudinally from the first fluid inlet opening to the first fluid outlet opening;
- (c) a plurality of second fluid flow passages, each of which comprises the space between the central portions of an adjacent pair of said tubes, each of the second fluid flow passages having a pair of longitudinally-spaced ends and a pair of transversely spaced sides, each of the second fluid flow passages being sealed along its ends by the end portions of said adjacent pair of tubes;
- and
- (d) a pair of side plates covering the transversely spaced sides of the second fluid flow passages, the side plates engaging the side walls of the tubes in the core and being sealed to the tube side walls in the end portions of the tubes, wherein a second fluid inlet manifold is provided in one of the side plates and a second fluid outlet manifold is provided in one of the side plates, each of the manifolds communicating with each of the second fluid flow passages.
A method for manufacturing a heat exchanger comprising a core comprised of a stack of open-ended tubes, each of the tubes having a top wall, a bottom wall, side walls connecting the top and bottom walls, a hollow interior enclosed by the top, bottom and side walls, and inlet and outlet openings for the first fluid, wherein each of the tubes has a pair of end portions spaced apart along a longitudinal axis and a central portion located between the end portions, the end portions of adjacent tubes in the core being sealed to one another along their top and bottom walls, wherein the end portions are greater in height than the central portions of the tubes such that the central portions of adjacent tubes in the core are spaced from one another;
- a plurality of first fluid flow passages, each of which comprises the hollow interior of one of the tubes and extends longitudinally from one open end of the tube to the other open end;
- a plurality of second fluid flow passages, each of which comprises the space between the central portions of an adjacent pair of said tubes, each of the second fluid flow passages having a pair of longitudinally-spaced ends and a pair of transversely spaced sides, each of the second fluid flow passages being sealed along its ends by the end portions of said adjacent pair of tubes;
- and a pair of U-shaped side plates, each of which has a side wall covering one side of the core and a pair of longitudinally-extending edges which are sealed to an uppermost tube in the core and a lowermost tube in the core, respectively, the side plates having inlet and outlet openings for the second fluid;
- the method comprising:
- (a) stacking said tubes to form said core;
- (b) attaching said U-shaped side plates to opposite sides of the core with one of the longitudinally-extending edges of each side plate engaging the top wall of the uppermost tube in the core and the other edge of each side plate engaging the bottom wall of the lowermost tube in the core, wherein the edges of the side plates frictionally engage the uppermost and lowermost tubes to retain the tubes in position in said core;
- and
- (c) heating the core with the attached side plates for a time and at a temperature sufficient to seal the end portions of adjacent tubes together, to seal the longitudinally-extending edges of the side plates to the uppermost and lowermost tubes in the core, and to seal the side plates to the tube side walls in the end portions of the tubes.
Dependencies are inferred from the claim text.