Finless heat exchanger apparatus and methods
An apparatus and methods are provided for finless heat exchanger cores. A heat exchanger core includes an inlet header and an outlet header. The heat exchanger core also includes one or more curved channel frames disposed at least partially between the inlet header and the outlet header. The one or more curved channel frames have a first end and a second end, and one or more fluid passageways that direct flow of a first fluid in a first direction therethrough from the first end to the second end. In some embodiments, at least one of the one or more curved channel frames includes a rounded leading edge and a tapered trailing edge.
1. A heat exchanger core, comprising:
an inlet header;
an outlet header; and
one or more curved channel frames disposed at least partially between the inlet header and the outlet header, each of the one or more curved channel frames having a first end and a second end, each of the one or more curved channel frames having a plurality of fluid passageways formed in a cross section of the respective curved channel frame that each direct flow of a first fluid in a first direction therethrough from the first end to the second end, and each of the one or more curved channel frames defining a sinusoidal profile in a direction that is perpendicular to the first direction, the sinusoidal profile having one or more crests and one or more troughs;
wherein one or more of the one or more curved channel frames includes a rounded leading edge and a tapered trailing edge; and
wherein the plurality of fluid passageways are disposed and separated from each other along the sinusoidal profile, each of the plurality of fluid passageways is defined on all sides by a plurality of inner walls of the respective curved channel frame, the plurality of inner walls comprises an upper inner wall and a lower inner wall, and each of the upper inner wall and the lower inner wall is curved to be parallel to the sinusoidal profile.
2. The heat exchanger core of claim 1 , wherein the rounded leading edge has a radius within a range of about 1 mm to about 4 mm.
3. The heat exchanger core of claim 1 , wherein the tapered trailing edge has a taper angle within a range of about 10 degrees to about 60 degrees.
4. The heat exchanger core of claim 1 , wherein each of the plurality of fluid passageways of each of the one or more curved channel frames are configured to withstand a temperature of the first fluid that is within a range of about −50 degrees Celsius to about 300 degrees Celsius.
5. The heat exchanger core of claim 1 , wherein the one or more curved channel frames are disposed at a frame density along a length in the heat exchanger core, the frame density being within a range of about 0.5 curved channel frames per inch to about 6 curved channel frames per inch.
6. The heat exchanger core of claim 1 , wherein the heat exchanger core comprises two or more curved channel frames, and the two or more curved channel frames are spaced from each other by a distance within a range of about 1 mm to about 30 mm.
7. The heat exchanger core of claim 1 , wherein the sinusoidal profile has an amplitude of about 1 mm to about 10 mm.
8. The heat exchanger core of claim 1 , wherein the one or more crests and the one or more troughs are disposed at a peak density along a length, the peak density being within a range of about 1 peak per inch to about 8 peaks per inch.
9. A heat exchanger core, comprising:
an inlet header;
an outlet header; and
one or more curved channel frames disposed at least partially between the inlet header and the outlet header, each of the one or more curved channel frames having a first end and a second end, each of the one or more curved channel frames having a plurality of fluid passageways formed in a cross section of the respective curved channel frame that each flow a first fluid in a first direction therethrough from the first end to the second end, and each of the one or more curved channel frames defining a sinusoidal profile in a direction that is perpendicular to the first direction, the sinusoidal profile having one or more crests and one or more troughs;
wherein at least one of the one or more curved channel frames has the cross section and a first length defined between the inlet header and the outlet header; and
wherein the cross section is curved and-substantially continuous throughout the first length; and
wherein the plurality of fluid passageways are disposed and separated from each other along the sinusoidal profile, each of the plurality of fluid passageways is defined on all sides by a plurality of inner walls of the respective curved channel frame, the plurality of inner walls comprises an upper inner wall and a lower inner wall, and each of the upper inner wall and the lower inner wall is curved to be parallel to the sinusoidal profile.
10. The heat exchanger core of claim 9 , wherein the first end and the second end of each of the one or more curved channel frames define a second length therebetween, and the cross section of at least one of the one or more curved channel frames is curved and substantially continuous throughout the second length.
11. The heat exchanger core of claim 9 , wherein the sinusoidal profile has an amplitude of about 1 mm to about 10 mm.
12. The heat exchanger core of claim 9 , wherein the one or more crests and the one or more troughs are disposed at a peak density along a length, the peak density being within a range of about 1 peak per inch to about 8 peaks per inch.
13. A heat exchanger core, comprising:
one or more curved channel frames, each of the one or more curved channel frames having a first end, a second end, an inlet portion adjacent to the first end, and an outlet portion adjacent to the second end;
a plurality of fluid passageways formed in a cross section of one of the one or more curved channel frames that each direct flow of a first fluid in a first direction therethrough from the first end to the second end, wherein each of the one or more curved channel frames defines a sinusoidal profile in a direction that is perpendicular to the first direction, the sinusoidal profile having one or more crests and one or more troughs, the plurality of fluid passageways are disposed and separated from each other along the sinusoidal profile, each of the plurality of fluid passageways is defined on all sides by a plurality of inner walls of the respective one of the one or more curved channel frames, the plurality of inner walls comprises an upper inner wall and a lower inner wall, and each of the upper inner wall and the lower inner wall is curved to be parallel to the sinusoidal profile;
an inlet tank, comprising:
an inlet header disposed around the inlet portion of each of the one or more curved channel frames, and
an inlet cover welded to the inlet header, thereby defining a first welded joint;
an outlet tank, comprising:
an outlet header disposed around the outlet portion of each of the one or more curved channel frames; and
an outlet cover welded to the outlet header, thereby defining a second welded joint.
14. The heat exchanger core of claim 13 , wherein the first end and the second end of each of the one or more curved channel frames are both disposed between the first welded joint and the second welded joint.
15. The heat exchanger core of claim 13 , wherein the inlet header is brazed to the inlet portion of each of the one or more curved channel frames thereby defining a first set of one or more brazed joints, and the outlet header is brazed to the outlet portion of each of the one or more curved channel frames thereby defining a second set of one or more brazed joints; and wherein the first set of one or more brazed joints and the second set of one or more brazed joints are both disposed between the first welded joint and the second welded joint.
16. The heat exchanger core of claim 13 , wherein the first end of each of the one or more curved channel frames extends into an inlet volume defined by the inlet tank, and the second end of each of the one or more curved channel frames extends into an outlet volume defined by the outlet tank.
17. A method of manufacturing a heat exchanger core, comprising:
forming one or more curved channel frames, each of the one or more curved channel frames having a first end, a second end, an inlet portion adjacent to the first end, and an outlet portion adjacent to the second end, each of the one or more curved channel frames having a plurality of fluid passageways formed in a cross section of the respective curved channel frame that each direct flow of a first fluid in a first direction therethrough from the first end to the second end, and each of the one or more curved channel frames defining a sinusoidal profile in a direction that is perpendicular to the first direction, the sinusoidal profile having one or more crests and one or more troughs,
wherein the plurality of fluid passageways are disposed and separated from each other along the sinusoidal profile, each of the plurality of fluid passageways is defined on all sides by a plurality of inner walls of the respective curved channel frame, the plurality of inner walls comprises an upper inner wall and a lower inner wall, and each of the upper inner wall and the lower inner wall is curved to be parallel to the sinusoidal profile;
disposing each of the one or more curved channel frames into an inlet header and an outlet header such that the first end of each of the one or more curved channel frames is received in a corresponding opening in the inlet header, and the second end of the one or more curved channel frames is received in a corresponding opening in the outlet header;
brazing the one or more curved channel frames to the inlet header and the outlet header, thereby forming a first set of one or more brazed joints adjacent to the inlet header and a second set of one or more brazed joints adjacent to the outlet header;
welding an inlet cover to the inlet header, thereby forming an inlet tank that defines an inlet volume; and
welding an outlet cover to the outlet header, thereby forming an outlet tank that defines an outlet volume.
18. The method of claim 17 , wherein welding the inlet cover to the inlet header is performed using one or more of tungsten inert gas (TIG) welding, metal inert gas (MIG) welding, laser welding, friction stir welding (FSW), or plasma welding.
19. The method of claim 17 , wherein welding the inlet cover to the inlet header is performed at a distance of at least about 15 mm from the first set of one or more brazed joints.
20. The method of claim 17 , wherein brazing the one or more curved channel frames to the inlet header and the outlet header comprises placing the one or more curved channel frames, the inlet header, and the outlet header into an oven.
21. The method of claim 17 , wherein brazing the one or more curved channel frames to the inlet header and the outlet header comprises exposing the one or more curved channel frames, the inlet header, and the outlet header to a temperature that is at or above a melting temperature of a braze material.