US20080164015A1

US20080164015A1 - Contra-tapered tank design for cross-counterflow radiator

Info

Publication number: US20080164015A1
Application number: US11/649,609
Authority: US
Inventors: Steven James Papapanu
Original assignee: Delphi Technologies Inc
Current assignee: Delphi Technologies Inc
Priority date: 2007-01-04
Filing date: 2007-01-04
Publication date: 2008-07-10

Abstract

The invention relates to a cross-counterflow heat exchanger, such as a cross-counterflow radiator for a motor vehicle, having an improved inlet/outlet tank wherein the inlet and outlet chambers are laterally off-set allowing the inlet and outlet ports to be oriented in the same general direction toward the fluid source; more particularly, the inlet and outlet chambers are tapered thereby providing improved flow distribution and pressure drop for fluid flow; still more particularly, the return tank inlet and outlet chambers are contra-tapered allowing the inlet and outlet ports to be substantially aligned resulting in a laterally compact heat exchanger.

Description

TECHNICAL FIELD OF INVENTION

The invention relates to a cross-counterflow heat exchanger, such as a cross-counterflow radiator for a motor vehicle, having an improved inlet/outlet tank wherein the inlet and outlet chambers are contra-tapered, thereby allowing the inlet and outlet ports to extend in the same general direction toward a fluid source.

BACKGROUND OF INVENTION

Cross-counter flow heat exchangers, such as a cross-counter flow radiator, are used to convey heat away from hot powertrain components such as the engine, transmission, compressor, or even a fuel cell of an automobile. With the advent of new powertrain cooling challenges, the need for mass reduction, and the decreasing available space within the engine compartment of an automobile, cross-counter flow radiators are becoming more desirable because of its higher cooling capacity per unit volume.
A cross-counter flow radiator is part of a closed loop system wherein the radiator is hydraulically connected to passageways within an engine or other powertrain heat source through which a heat transfer fluid, such as a mixture of water and ethylene glycol, is circulated. A stream of air is blown perpendicularly to a face of the radiator for heat transfer to the ambient air.
Shown in FIG. 1 is a typical cross-counter flow heat exchanger 100 known in the art having a pair of opposed faces 105 a, 105 b, one facing toward, and one away from, the source of heat of which is a vehicle engine here. The typical cross-counter flow heat exchanger 100 is formed of a central core 110 having a multitude of parallel tubes 115. Between the tubes are typically fins 118 to increase the surface area for optimal heat dissipation. FIG. 1A is a cut away top view of FIG. 1 along section line 1A. Shown in FIG. 1A is a tube partition 120 running along the interior length of one of the parallel tubes 115. A return tank 130 is attached to core end 133 a, aligned with the parallel tube openings, and an inlet/outlet tank 135 is attached to the other core end 133 b.
Shown in FIG. 1A, the inlet/outlet tank 135 has a tank partition 140 along the longitudinal axis 145, effectively dividing the tank into a first chamber 150 a and a second chamber 150 b, wherein the first chamber 150 a has an inlet port 155 a and the second chamber 150 b having an outlet port 155 b. The inlet/outlet tank 135 is mated to the core end 133 b with a header plate 160 in between. The inlet/out tank partition 140 cooperates with the header plate 160, tube partition 120, and return tank 130 to define first fluid passageways 125 a and second fluid passageways 125 b.
The hot heat transfer fluid from the internal combustion engine flows into the first chamber 150 a by way of inlet port 155 a and then through first passageways 125 a to return tank 130. Return tank 130 is hydraulically connected to second passageways 125 b through which the heat transfer fluid travels to second chamber 150 b before exiting outlet port 155 b. As the hot fluid flows through passageways 125 a, 125 b heat is released to the ambient air by convection. It should be appreciated that the heat transfer fluid flows in substantially parallel but counter directional paths in the first passageways 125 a along first face 105 a and in the opposite direction through second passageways 125 b along the opposed second face 105 b.
Unlike conventional cross flow radiators, cross-counterflow radiators have the inlet and outlet ports at the same end of the heat exchanger core. The engine is the hot fluid source 165 supplying the cross-counter flow heat exchanger. FIG. 1 shows a prior art design where the inlet and outlet extend in the same direction laterally outward from inlet/outlet tank, not toward fluid source 165.
FIG. 2 is a perspective view of another prior art cross-counter flow radiator 200 design where the inlet port 255 a and outlet port 255 b extend in opposing directions on inlet/outlet tank 235. Inlet port 255 a extends toward the engine, the fluid source 220; however, outlet port 255 b extends directly away from the fluid source 220.
A disadvantage of the prior art inlet/ outlet tanks 135, 235 is that additional hardware such as elbows, hoses, clamps, and fittings are required to orient either the inlet ports 155 a, 255 a or outlet ports 155 b, 255 b toward the fluid source 165, 220. This results in additional space utilization, weight, plumbing hardware, potential leak points, labor, and associated cost.
Furthermore, the inlet/ outlet tank designs 135, 235 shown in FIG. 1 and FIG. 2 are substantially uniform in cross sectional area and function primarily as manifolds for distribution of heat transfer fluid across the central cores 110, 210. It is known in the art that tapered tanks provide a more desired fluid flow profile across the central core 110, 210.
For design criteria where space is limited, such as the engine compartment of a modern vehicle, there exists a need for a cross-counter flow heat exchanger that is compact, robust, economical to manufacture, and provides the same desired fluid flow distribution and pressure drop advantages as those of tapered tanks.

SUMMARY OF THE INVENTION

The invention relates to a cross-counterflow heat exchanger, such as a cross-counterflow radiator for a motor vehicle, having an improved inlet/outlet tank wherein the inlet and outlet chambers are contra-tapered, thereby allowing the inlet and outlet ports to extend in the same general direction toward the fluid source, and provide improved flow distribution and pressure drop for fluid flow.
The cross-counterflow fluid heat exchanger has a central core with two opposing lateral faces and two opposing core ends. The central core is constructed from a plurality of substantially parallel liquid flow tubes with fins in between the tubes for improved heat dissipation and added structural integrity. The flow tubes have an internal lengthwise partition defining a plurality of first fluid passageways along one face and a plurality of second fluid passageways along the opposed face. The heat exchanger is supplied with heated fluid from a fluid source, such as that of an internal combustion engine of a motor vehicle, located spaced apart from one of the opposed faces.
A return tank is attached to one end of the central core corresponding to the flow tube openings at one core end and an inlet/outlet tank is attached to the opposite end of the parallel tube openings. The inlet/outlet tank has a first chamber that hydraulically communicates with the first fluid passageways and a second chamber that hydraulically communicates with the second fluid passageways.
Unlike a conventional inlet/outlet tank, which has a single lateral or side surface facing the engine, each chamber in the inlet/outlet tank of the subject invention has a distinct lateral surface, offset from the plane of the other, and large enough to allow a port to extend therefrom in the same direction, toward the engine, without interference with the other chamber or port. In addition, in the embodiment disclosed, each chamber of the inlet/outlet tank is contra-tapered, that is, tapered in the opposite direction from the other chamber. This shape provides the offset lateral surfaces that are both wide enough to allow the desired location and orientation of the ports, as well as providing for improved flow distribution.
An advantage of the present invention is that the inlet and outlet port openings extend in the same general direction toward the fluid source. This preferred orientation of the inlet/outlet ports eliminates the need for additional plumbing hardware such as elbows, hoses, clamps, and fittings to redirect the heat exchange fluid flow toward the fluid source, thereby resulting in less weight and reduced potential leak points.
A further advantage of contra-tapering the chambers of the inlet/out tank toward the central core opposing surfaces is that this provides a compact inlet/outlet tank design resulting in a laterally compact heat exchanger. A compact inlet/outlet tank design also allows for lesser coolant usage resulting in additional weight savings.
A still further advantage is that the contra tapered chambers provide improved flow distribution and pressure drop for the heat exchange fluid as it flows through the central core. This allows for even more compact heat exchanger design due to greater increase efficiency of the heat exchanger.
The features and advantages of the present invention will become apparent to those skilled in the art from analysis of the following written description, the accompanying drawings and claims.

BRIEF DESCRIPTION OF DRAWINGS

This invention will be further described with reference to the accompanying drawings in which:

FIG. 1 is a perspective view of a cross-counterflow heat exchanger showing an inlet and outlet extending from a common exterior surface of an inlet/outlet tank in a direction that is perpendicular to the fluid source.

FIG. 1A is a cut away top view of FIG. 1 along section line 1A showing directions of fluid flow.

FIG. 2 is a perspective view of a cross-counterflow heat exchanger showing an inlet and outlet extending from opposing surfaces of an inlet/outlet tank.

FIG. 3 is a perspective view of a cross-counterflow heat exchanger, in accordance with the invention, showing an inlet and outlet extending toward the fluid source.

FIG. 3A is a cut away top view of FIG. 3 along elevation section 3A showing directions of fluid flow, in accordance with the invention.

FIG. 4 is an end view of the inlet/outlet tank detailing the interior surfaces with the inlet and outlet extending from the same surface, in accordance with the invention.

FIG. 5 is a side view of the inlet/outlet tank showing tapered chamber lateral exterior surfaces, in accordance with the invention.

FIG. 6 is a perspective view of the inlet/outlet tank, in accordance with the invention.

DETAILED DESCRIPTION OF INVENTION

Shown in FIGS. 3 through 6, in accordance with a preferred embodiment of this invention, is a cross-counter flow heat exchanger such as a cross-counter flow radiator utilized to cool an internal combustion engine of an automobile.
FIG. 3 is a perspective view of cross-counterflow heat exchanger 300 having a central core 305 with opposing faces 310 a, 310 b, one facing toward, and one away from hot fluid source 345. Fluid source 345, in this case, would be an internal combustion engine of a motor vehicle (not shown). Both of the opposed faces 310 a, 310 b are situated substantially perpendicular to hot fluid source 345. Central core 305 has a plurality of substantially parallel liquid flow tubes 315 for conveyance of heat exchange fluid. Fins 318 are inter-disposed between flow tubes 315 for improved heat dissipation and increased structural integrity. Outer flow tubes 315 of central core 305 are bounded by first support member 314 a and a second support member 314 b. First and second support members 314 a, 314 b are both substantially parallel with flow tubes 315.
FIG. 3A is a cut away top view of FIG. 3 along elevation line 3A showing directions of fluid flow through flow tubes 315. Shown along the interior length of flow tubes 315 is partition 320 defining first fluid passageways 325 a and second fluid passageways 325 b. Flow tubes 315 and partitions 320 can be manufactured as an integral extrusion or fabricated from flat stock.
In reference to both FIGS. 3 and 3A, return tank 330 is attached to an end of the central core corresponding to the flow tube openings 319 b. Inlet/outlet tank 335 is attached to the opposite end of the central core corresponding to flow tube openings 319 a. Inlet/outlet tank 335 has first inlet/outlet port 340 a and second inlet/outlet port 340 b extending from a same side surface in a direction generally toward fluid source 345.
In reference to FIG. 4 through 6, inlet/outlet tank 335 has longitudinal axis 355 along interior length of inlet/outlet tank 335. Inlet/out tank 335 has internal partition 350 along longitudinal axis 355 cooperating with interior surface 360 to define first chamber 365 a and second chamber 365 b. First chamber 365 a and second chamber 365 b are contra-tapered, that is, tapered in the opposite direction from the other chamber. Contra-tapering of first chamber 365 a and second chamber 365 b provides for improved flow distribution and pressure drop for fluid flow through the central core. Contra-tapering of chambers 365 a, 365 b also provides for distinct external features for inlet/outlet tank 335 that allow for inlet/ outlet ports 340 a, 340 b to be orientated toward fluid source 345.
The external features of first chamber 365 a include lateral exterior surface 370 a and exterior end edge 375 a. The external features of second chamber 365 b include lateral exterior surface 370 b and exterior end edge 375 b. First and second chambers' lateral exterior surfaces 370 a, 370 b are both laterally offset, as well as offset from the plane of the other. Both lateral exterior surfaces 370 a, 370 b face fluid source 345 and are wide enough to allow the desired location and orientation of inlet/ outlet ports 340 a, 340 b.
In reference to FIG. 4, defining the opening of inlet/outlet tank 335 is exterior perimeter edge 362. In reference to FIG. 5, the shape of first chamber lateral exterior surface 370 a is substantially triangular, wherein the latitudinal distance W between first chamber exterior edge 375 a and exterior perimeter edge 362 by first support member 314 a is greater than the latitudinal distance Z between first chamber exterior edge 375 a and exterior perimeter edge 362 by second support member 314 b.
The shape of the second chamber lateral exterior surface 370 a is also substantially triangular; however, a portion of second chamber lateral exterior surface 370 is obscured by first chamber 365 a. The latitudinal distance Y between second chamber exterior end edge 375 b and exterior perimeter edge 362 by first support member 314 a is less than the latitudinal distance X between said second chamber exterior end edge 375 b and exterior perimeter edge 362 by second support member 314 b.
Shown in FIG. 5, the overall shape of first and second chamber lateral exterior surfaces 370 a, 370 b, when view from fluid source 345, is essentially that of two overlapping right triangles sharing a common leg, wherein the right angle of each triangle opposes each other. Protruding from the first chamber lateral exterior surface 370 a is a first inlet/outlet port 340 a and protruding from the second chamber lateral exterior surface 370 b is a second inlet/outlet port 340 b. Both of the inlet/ outlet ports 340 a, 340 b extend in the same general direction toward fluid source 345 and are also substantially aligned longitudinally. This preferred orientation of inlet/ outlet ports 340 a, 340 b eliminates the need for additional plumbing hardware such as elbows, hoses, clamps, and fittings to redirect the heat exchange fluid flow toward the fluid source.
Contra-tapering first and second chambers 365 a, 365 b of inlet/out tank 335 also provides for an overall laterally compact inlet/outlet tank design. Furthermore, tapered chambers provide improved flow distribution and pressure drop for the heat exchange fluid as it flows through central core 305 and thereby increases the heat transfer efficiency of the heat exchanger.
In reference to FIG. 3A, the hot heat transfer fluid from the internal combustion engine flows into the first chamber 365 a by way of first inlet/outlet port 340 a and then through first passageways 325 a to return 330 tank. Return tank 330 is hydraulically connected to second passageways 325 b through which the heat transfer fluid travels to second chamber 365 b before exiting inlet/outlet port 340 b. As the hot fluid flows through passageways 325 a, 325 b in parallel but opposite direction, heat is released to the ambient air by convection.
While this invention has been described in terms of the preferred embodiments thereof, it is not intended to be so limited, but rather only to the extent set forth in the claims that follow.

Claims

1. In a cross-counterflow fluid heat exchanger with a pair of opposed faces having:

a heat exchanger core with a plurality of liquid flow tubes, wherein said tubes have a lengthwise partition defining a first fluid passageway along one face and a second fluid passageway along the opposed face; and in which said heat exchanger is supplied with fluid from a source located spaced from one of said opposed faces, the improvement comprising,

an inlet/outlet tank on one end of said core having:

a first chamber hydraulically communicating with said first fluid passageway;

a second chamber hydraulically communicating with said second fluid passageway;

a first chamber lateral exterior surface facing said fluid source;

a second chamber lateral exterior surface facing said fluid source, wherein one of said chamber lateral exterior surfaces extends beyond the other;

a first inlet/outlet port through said first chamber lateral exterior surface and extending generally toward said fluid source; and

a second inlet/outlet port through said second chamber lateral exterior surface and also extending generally toward said fluid source.

2. A cross-counterflow fluid heat exchanger of claim 1 wherein said first chamber lateral exterior surface and said second chamber lateral exterior surface are on off-set substantially parallel planes.

3. A cross-counterflow fluid heat exchanger of claim 2 wherein at least one of said chamber lateral exterior surfaces is tapered.

4. A cross-counterflow fluid heat exchanger of claim 2 wherein said first chamber lateral exterior surface and said second chamber lateral exterior surface are contra-tapered.

5. A cross-counterflow fluid heat exchanger of claim 2 wherein at least one of said chambers is tapered.

6. A cross-counterflow fluid heat exchanger of claim 2 wherein said first chamber and said second chamber are contra-tapered.

7. A cross-counter flow fluid heat exchanger of claim 1 wherein:

said heat exchanger core further comprises a first support member and a second support member bounding either side of said core, wherein said support members are substantially parallel with said flow tubes; and

said inlet/outlet tank further comprising of:

an elongated cavity having an interior surface and an exterior perimeter edge along open face of cavity,

a longitudinal axis along length of cavity;

a partition along longitudinal axis together with said interior surface defining said first chamber and said second chamber;

a first chamber exterior edge connected to said first chamber exterior surface; and

a second chamber exterior edge connected to said second chamber exterior surface;

wherein the distance W between said first chamber exterior edge and said exterior perimeter edge by said first support member is greater than the distance Z between said first chamber exterior edge and said exterior perimeter edge by said second support member end; and

wherein the distance Y between said second chamber exterior edge and said exterior perimeter edge by said first support member is less than the distance X between said second chamber exterior end edge and said exterior perimeter edge near second support member.

8. A cross-counter flow fluid heat exchanger of claim 7 wherein said first chamber lateral exterior surface and second chamber lateral exterior surface are substantially triangular in shape.

9. A cross-counter flow fluid heat exchanger of claim 1 wherein said fluid source is an internal combustion engine.

10. In a cross-counterflow fluid heat exchanger with a pair of opposed faces for an internal combustion engine having:

a heat exchanger core with a plurality of liquid flow tubes, wherein said tubes have a lengthwise partition defining a first fluid passageway along one face and a second fluid passageway along the opposed face; and in which said heat exchanger is supplied with fluid from a source located spaced from one of said opposed faces, the improvement comprising:

an inlet/outlet tank on one end of said core having:

a first chamber hydraulically communicating with said first fluid passageway;

a second chamber hydraulically communicating with said second fluid passageway;

a first chamber lateral exterior surface facing said engine;

a second chamber lateral exterior surface facing said engine, wherein one of said chamber lateral exterior surfaces extends beyond the other;

a first inlet/outlet port through said first chamber lateral exterior surface and extending generally toward said engine; and

a second inlet/outlet port through said second chamber lateral exterior surface and also extending generally toward said engine.

11. A cross-counterflow fluid heat exchanger of claim 10 wherein said first chamber lateral exterior surface and said a second chamber lateral exterior surface are on off-set substantially parallel planes.

12. A cross-counterflow fluid heat exchanger of claim 11 wherein at least one of said chambers is tapered.

13. A cross-counterflow fluid heat exchanger of claim 12 wherein said first chamber and said second chamber are contra-tapered.