GB2544979A

GB2544979A - A heat sink of source apparatus and method

Info

Publication number: GB2544979A
Application number: GB1521177.4A
Authority: GB
Inventors: J Howe Daniel; Calcutt Nicholas; Gobrial Goergeuos
Original assignee: Rolls Royce PLC
Current assignee: Rolls Royce PLC
Priority date: 2015-12-01
Filing date: 2015-12-01
Publication date: 2017-06-07
Also published as: GB201521177D0

Abstract

A heat sink or heat source apparatus 2 comprises a fluid passageway 4 with an outward portion 12 extending away from an inlet 8, and a return portion 14 extending towards an outlet 10. A wall 6 is thermally coupled to the fluid passageway and has a conduction surface which contacts a component to be cooled or heated. The outward and return portions have complementary paths such that they run alongside each other and temperatures of the outlet portion are offset by temperatures of the return portion to provide a constant temperature along the conduction surface. The inlet and outlet may be adjacent. The passageway may be formed by a tube and may be serpentine with the outward and return portions interleaved with each other. The paths of the outward and return portions may be helical. The wall may be planar or cylindrical, and may be formed by the fluid passageway. Partition walls (22, 24, fig 6), which may be thermally conductive, may separate the outward and return portions. Adjacent regions of each portion may be separated by a thermally insulating material.

Description

A HEAT SINK OR SOURCE APPARATUS AND METHOD

The disclosure relates to a heat sink or source apparatus for cooling or heating a component, and to a corresponding method.

Heat sinks in the form of water jackets are commonly used to cool components, such as those found in electrical and mechanical systems. Generally, water jackets are placed around a component to be cooled. Water having a temperature less than that of the component is pumped through the water jacket such that heat is transferred from the component to the water in order to cool the component. In order to allow the water jacket to be used for prolonged periods, the water is circulated out of the water jacket and is cooled before being returned to the water jacket.

Such water jackets typically exhibit non-uniform cooling of components since the water is heated as it passes through the water jacket.

It is therefore desirable to provide an improved heat sink or source apparatus for cooling or heating a component.

According to an aspect, there is provided a heat sink or source apparatus for cooling or heating a component, the heat sink or source apparatus comprising: a fluid passageway for conveying a cooling or heating fluid; a wall thermally coupled to the fluid passageway, the wall having a conduction surface which, in use, contacts the component; wherein the fluid passageway has an outward portion generally extending away from an inlet and a return portion generally extending back from the outward portion towards an outlet; wherein the outward and return portions of the fluid passageway have complementary paths such that they run alongside one another and such that temperatures of the outward portion are offset by temperatures of the return portion so as to provide a substantially constant temperature along the length of the conduction surface.

The outlet may be positioned adjacent the inlet.

The paths of the outward and return portions may be serpentine and interleaved with one another.

The outward and return portions may be coupled by a thermally conductive material.

Adjacent regions of the outward and/or return portion of the fluid passageway may be separated by a thermally insulating material.

The return portion of the fluid passageway may contact the outward portion of the fluid passageway along its length.

The fluid passageway may be formed by a tube. A wall of the tube may form the thermally conductive material. A partition wall may separate and partly define the outward portion of the fluid passageway and the return portion of the fluid passageway.

The partition wall may form the thermally conductive material.

The outward and return portions may be non-planar.

The paths of the outward and return portions may be helical.

The helical paths of the outward and return portions may comprise at least one turn.

The outward and return portions of the fluid passageway may be partly defined by helicoid flights.

The wall thermally coupled to the fluid passageway may define an internal passageway which is configured to receive the component.

The wall thermally coupled to the fluid passageway may be formed by an outer wall of the heat sink or source apparatus, wherein the heat sink or source apparatus is configured to be received within the component.

The wall thermally coupled to the fluid passageway may be cylindrical.

The outward and return portions of the fluid passageway may be planar.

The fluid passageway may form the wall thermally coupled to the fluid passageway.

According to another aspect, there is provided a method of cooling or heating a component using the apparatus as described above, the method comprising: placing the component against the conduction surface of the apparatus; and passing a fluid through the fluid passageway such that it passes from the inlet to the outlet via the outward and return portions; wherein the temperatures of the outward portion are offset by the temperatures of the return portion such that the component is exposed to a substantially constant temperature along the length of the conduction surface.

The invention may comprise any combination of the features and/or limitations referred to herein, except combinations of such features that are mutually exclusive.

Embodiments will now be described, by way of example, with reference to the accompanying drawings, in which:

Figure 1 is a perspective view of a heat sink apparatus;

Figure 2 is a cross-sectional plan view of the heat sink apparatus of Figure 1;

Figure 3 is a graph of temperature versus position through the heat sink apparatus of Figure 1;

Figure 4 is a cross-sectional plan view of another heat sink apparatus;

Figure 5 is a cross-sectional plan view of another heat sink apparatus;

Figure 6 is a cross-sectional plan view of another heat sink apparatus;

Figure 7 is a cross-sectional side view of another heat sink apparatus; and

Figure 8 is a cross-sectional end view of the heat sink apparatus of Figure 7 along the line A-A.

Figures 1 and 2 show a heat sink apparatus 2. The heat sink apparatus 2 generally comprises a tube 4 and a wall 6 (a plate or the like) against which the tube 4 is located. The materials of the tube 4 and wall 6 and their arrangement allow thermal conduction between the tube 4 and the wall 6. The tube 4 comprises an inlet 8 and an outlet 10 positioned adjacent one another. The tube 4 defines a fluid passageway. The tube 4 and fluid passageway may be notionally divided into an outward portion 12 which carries fluid away from the inlet 8 and a return portion which carries fluid back towards the outlet 10.

The outward portion 12 of the tube 4 is located in a single plane positioned adjacent the wall 6. The outward portion 12 follows a serpentine path extending between the inlet 8 and an interface or turning point 18 between the outward portion 12 and the return portion 14. Specifically, the outward portion 12 comprises a plurality of parallel sections (five are shown) which are connected by connecting portions (which may be curved portions or straight portions connected to adjacent parallel sections by elbows) at alternate ends. Likewise, the return portion 14 is also located in a single plane positioned adjacent the wall 6, and follows a serpentine path extending between the interface 18 and the outlet 10. Again, the serpentine path of the return portion 14 comprises a plurality of parallel sections (five are shown) which are connected by connecting portions at alternate ends. The serpentine paths of the outward and return portions 12, 14 are complementary such that the return portion 14 of the tube 4 runs alongside the outward portion 12, and is spaced therefrom by an equal distance along its length. The outward and return portions 12, 14 are therefore interleaved with one another. The connecting portions of the outward portion 12 alternate between longer sections at one end of the parallel sections (see positions B and D in Figure 2) and shorter sections at the opposing end of the parallel sections (see positions C and E in Figure 2). Similarly, the connecting portions of the return portion 14 alternate between longer sections at one end of the parallel sections (see positions G and I in Figure 2) and shorter sections at the opposing end of the parallel sections (see positions K and J in Figure 2). The longer connecting portions of the outward portion 12 are aligned with the shorter connecting portions of the return portion 14, and the shorter connecting portions of the outward portion 12 are aligned with the longer connecting portions of the return portion 14 so as to allow the outward and return portions 12, 14 to be interleaved with one another.

In use, a component 16 to be cooled is placed against the surface of the wall 6 such that the wall 6 is disposed between the component 16 and the tube 4. Fluid is supplied to the inlet 8, which passes along the outward portion 12, before passing along the return portion 14 and out of the outlet 10. The fluid may be water, oil, refrigerant, air, liquefied gas, or any other suitable coolant. The fluid may be cooled after leaving the outlet 10 before being recirculated to the inlet 8 or a continuous supply of fluid may be provided at the inlet 8 so as to provide fluid of substantially constant temperature at the inlet 8.

The temperature of the fluid supplied to the inlet 8 is less than that of the component 16. Accordingly, as the fluid passes along the tube 4, heat is transferred from the component 16 into the fluid, via the wall 6 and tube 4, such that the component 16 is cooled.

Figure 3 shows the variation in temperature of the fluid as it passes along the tube 4, with reference to the position labels shown in Figure 2. As described above, as the fluid passes along the tube 4, heat is transferred from the component 16, into the fluid. Accordingly, the temperature of the fluid gradually increases along the length of the tube 4 as it passes through the outward portion 12 (positions A to F) and the return portion 14 (positions F to K).

As described previously, the path of the return portion 14 of the tube 4 runs alongside the outward portion 12. As a result, the length of the outward portion 12 is approximately equal to the length of the return portion 14 and the interface represents the halfway point of the tube 4. The temperature at the interface 18 may be expected to be the average temperature of the fluid within the tube 4 with the temperatures in the outward portion 12 being lower and the temperatures in the return portion 14 being higher. At any position, the adjacent sections of the outward and return portions 12, 14 are the same distance from the interface 18 and thus the temperatures of the fluid within the outward and return portions 12, 14 at these sections differs from the average temperature by the same value, but opposite signs (i.e. one is hotter and the other is cooler).

For example, at positions A and K in Figure 2, the fluid in the outward portion 12 is at its coolest, whereas the fluid in the return portion 14 is at its hottest. The temperature of the outward and return portions 12, 14 offset one another such that the temperature exhibited in this region is substantially equal to the average of the two temperatures, which corresponds substantially to the temperature at the interface 18. As the distance to the interface 18 decreases, the difference in temperature between the outward and return portions 12, 14 similarly decreases. For example, at positions E and G in Figure 2, the temperature of the fluid in the outward and return portions 12, 14 differs only slightly from the temperature at the interface 18. Nevertheless, the temperature of the outward and return portions 12, 14 again offset one another such that the temperature exhibited in this region is substantially equal to the average of the two temperatures, which corresponds substantially to the temperature at the interface 18. Therefore, at all positions along the tube 4, the outward and return portions 12, 14 offset one another to produce a substantially uniform temperature across the wall 6. Consequently, the component 16 is exposed to a constant temperature across the surface contacting the wall 6 and thus the heat sink apparatus 2 provided uniform cooling.

Since the pair of passageways 12, 14 of the arrangement of Figures 1 and 2 follows a serpentine path, a uniform-cooling effect is provided in two dimensions, across a width and along a length of the wall 6. Alternative arrangements are also possible, such as spiral arrangements having an inlet and outlet disposed at an inner or an outer end of the spiral. In further alternative arrangements, the outward and return portion 12, 14 may be linear (i.e. the tube 4 is doubled back on itself).

Figure 4 shows another heat sink apparatus 102 which is similar to the heat sink apparatus 2. However, in contrast to the heat sink 2, the heat sink 102 comprises a thermally conductive material 120 which is disposed between the outward and return portions 12, 14 of the tube 4 so as to promote the transfer of heat therebetween. Accordingly, in use, heat is transferred from the fluid passing through the outward portion 12, through the thermally conductive material 120, and into the fluid passing through the return portion 14. This may provide a more uniform cooling effect along the length of the tube 4.

Although not shown, the parallel sections of the outward portion 12 which are adjacent to one another without any sections of the return portion 14 therebetween (i.e. the sections joined by the shorter connecting portions) may be separated by a thermally insulating material so as to prevent heat from being transferred between the parallel sections of the outward portion 12 itself and so promote heat transfer between the outward portion 12 and the return portion 14. Again, this may promote more uniform cooling. The return portion 14 may also be provided with a similar arrangement of thermally insulating material.

Figure 5 shows another heat sink apparatus 202 which is similar to the heat sink apparatus 2, but in which the outward and return portions 12, 14 are intertwined (in three-dimensions) rather than interleaved (in two-dimensions). Specifically, the serpentine paths of the outward and return portions 12, 14 are identical but offset laterally from one another. As the outward and return portions 12, 14 are not interleaved, the connecting portions can all have the same length such that the parallel sections are spaced evenly. The outward and return portions 12, 14 are, however, intertwined such that the return portion 14 alternately passes under and over the outward portion 12 at each connecting portion of the serpentine path. Although it is necessary for the outward and return portion 12, 14 to pass over and under each other and thus extend out-of-plane, the parallel sections of the outward and return portions 12, 14may be aligned in a single plane.

Figure 6 shows another heat sink apparatus 202 which is similar to the heat sink apparatus 2. However, the heat sink 302 differs from the arrangement described previously in that the fluid passageway is not formed by a tube or the like. Instead, a second wall (not shown) is positioned parallel to but spaced apart from the thermally conductive wall 6. First and second partition walls 22, 24 extend between the wall 6 and the second wall, and are spaced apart such that the fluid passageway 4 is defined between the thermally conductive wall 6, the second wall, and the first and second partition walls 22, 24. In this arrangement, the first partition wall 22 defines a single serpentine path and the second partition wall 24 divides the space into the outward and return portions 12, 14. As a result, opposing surfaces of the second wall 24 define part of the outward and return portions 12, 14 respectively.

Figure 7 shows another heat sink apparatus 402. The heat sink apparatus operates using the same principles as the apparatus described previously with reference to Figures 1 to 6, but has a hollow, cylindrical form which allows the heat sink apparatus 402 to function as a cooling jacket which surrounds a component to be cooled. The heat sink 402 generally comprises a thermally conductive cylindrical inner wall 426 and a cylindrical outer wall 428. The cylindrical inner wall 426 is disposed within the cylindrical outer wall 428 and spaced therefrom so as to define an annular chamber 430 therebetween. The cylindrical inner wall 426 and outer wall 428 are coaxial. A first endplate 432 extends between the inner wall 426 and the outer wall 428 at a proximal end of the heat sink 402. Likewise, a second endplate 434 extends between the inner wall 426 and the outer wall 428 at a distal end of the heat sink 402. An inlet conduit 442 and an outlet conduit 446 are connected to the first endplate 432. The inlet conduit 442 and the outlet conduit 446 have a distal end 444, 448 spaced from the first end plate 432 and a proximal end at the first end plate 432 which define an inlet 408 and an outlet 410 into and out of the annular chamber 430.

First and second thermally conductive helicoid flights 436, 438 are disposed within the annular chamber 430. The first and second helicoid flights 436, 438 extend between the inner and outer walls 426, 428 and extend from the first end plate 432, along the length of the annular chamber 430, towards the second end plate 434. The axes of the first and second helicoid flights 436, 438 are coaxial with the axes of the inner and outer cylindrical wall 426, 428. The first and second flights 436, 438 are rotationally offset from one other, in the same manner as a two-start thread. Accordingly, the first and second flights 436, 438 divide the annular chamber 430 into two helical passages forming an outward portion 412 and a return portion 414. The inlet 408 enters directly into the outward portion 412 and the outlet 410 exits from the return portion 414. The first and second flights 436, 438 only extend part way towards the second plate 434 such that a gap is formed between the flights 436, 438 and the second end plate 434. Accordingly, fluid communication is established between the outward portion 412 and the return portion 414 at a distal end of the annular chamber 430, such that the outward portion 412 and the return portion 414 define a continuous passageway allowing fluid to pass from the inlet 408 to the outlet 410. In alternative arrangements, one of the first or second flights 436, 438 may extend the entire length of the annular chamber 430 between the first end plate 432 and the second end plate 434 without there being a loss of fluid communication between the inlet 408 and the outlet 410.

As shown in Figure 8, the cylindrical inner wall 426 defines a central opening or bore 440. The central opening 440 is open at both ends of the heat sink 402 such that, in use, a component 16 to be cooled may be inserted into the central opening 440 and placed against the thermally conductive inner wall 426. The internal profile of the central opening 440 may substantially correspond to the external profile of the component 16 to be cooled.

The arrangement of Figures 7 and 8 operates in a similar manner to the arrangements described previously. Specifically, fluid is supplied to the inlet 408, which passes along the outward portion 412, before passing along the return portion 414 and out of the outlet 410. In this arrangement, the fluid travels circumferentially around the heat sink apparatus 402, and thus around the component 16 to be cooled. As per the previous arrangements, the temperature of the outward and return portions 412, 414 offset one another at all positions along the length and circumference of the annular chamber 430 to produce a substantially uniform temperature across the inner wall 426. The heat sink apparatus 402 is thus able to uniformly cool the component 16 disposed within the central opening 440.

Although the first and second flights 436, 438 comprise a plurality of turns, only a single turn may be used in certain applications.

Although the heat sink apparatus 402 has been described as receiving the component 16 within the opening 440, the component 16 may instead have a cylindrical (or any other shape) bore which receives the heat sink apparatus 402 having a thermally conductive outer wall 428. As the heat sink apparatus 402 would then not need a central opening 440, the inner wall 426 may be formed as a solid shaft. Various modifications may be made to the geometry of the heat sink apparatus to ensure adequate thermal coupling with the component to be cooled. For example, the planar arrangements described previously may in fact be curved or any other shape to conform to the component.

The outward portion 412 and the return portion 414 have been described as being helical. Nevertheless, arrangements in which the outward and return portions 412, 414 are non-helical are also possible. Such arrangements are still able to provide uniform cooling, provided the return portion 414 runs alongside the outward portion 412. For example, the outward portion 412 and the return portion 414 may follow a serpentine path, as described previously with reference to the planar arrangements of Figures 1 to 6. Although it has been described that both the first and second flights 436, 438 are thermally conductive, one or both of the first or second flights 436, 438 may be thermally insulating. Further, the outward portion 412 and the return portion 414 need not be formed by flights, as previously discussed. Instead, the outward portion 412 and the return portion 414 may be formed by tubes, or the like, as per the embodiments of Figures 1 to 5.

It will be appreciated that the fluid passageway of each of the arrangements described previously may be formed as a continuous circuit (to allow recirculation of the fluid) or may be extended from that shown. Consequently, the inlet and outlet need not be physical components, but rather may be considered as sections of the fluid passageway adjacent to the region in which heat is transferred between the fluid (from both the outward and return portions) and the component 16. Therefore, although the inlet and outlet may be adjacent to one another over this region, outside of this region the fluid passageway may diverge, if required.

Although it has described that the arrangements comprise an outward and a return portion which have complementary paths such that they run alongside one another, it will be appreciated that the apparatus may have more than two complementary paths which run alongside one another and average to produce a substantially uniform temperature across the surface.

The above arrangements are described as comprising a thermally conductive wall against which the component to be cooled is placed against. Although it has been described that the thermally conductive wall is a separate component from the fluid passageway, the thermally conductive wall may be formed by part of the fluid passageway. For example, the fluid passageway may be defined by tubes which have a flat or planar surface (e.g. having a square cross-section) such that, when arranged in a serpentine or helical form, the planar surfaces align to form a continuous surface against which the component can abut.

Although the apparatus are referred to as a heat sink apparatus for cooling a component, it will be appreciated that the same arrangement may be used as a heat source for heating a component simply by using a fluid which has a temperature at the inlet that is higher than that of the component. The apparatus, acting as a heat source, operates in a similar manner as when acting as a heat sink, and is able to uniformly heat the component.

The heat sink or source apparatus described herein may be used to heat or cool a variety of different components. For example, the apparatus may find applications in cooling computer processors, rocket/propulsion systems, large marine engines, or any other application where uniform cooling is desired. It may also be used to provide uniform heating in, for example, the food industry.

Claims

CLAIMS:

1. A heat sink or source apparatus for cooling or heating a component, the heat sink or source apparatus comprising: a fluid passageway for conveying a cooling or heating fluid; a wall thermally coupled to the fluid passageway, the wall having a conduction surface which, in use, contacts the component; wherein the fluid passageway has an outward portion generally extending away from an inlet and a return portion generally extending back from the outward portion towards an outlet; wherein the outward and return portions of the fluid passageway have complementary paths such that they run alongside one another and such that temperatures of the outward portion are offset by temperatures of the return portion so as to provide a substantially constant temperature along the length of the conduction surface.

2. A heat sink or source apparatus as claimed in claim 1, wherein the outlet is positioned adjacent the inlet.

3. A heat sink or source apparatus as claimed in any of claims 1 or 2, wherein the paths of the outward and return portions are serpentine and interleaved with one another.

4. A heat sink or source apparatus as claimed in any preceding claim, wherein the outward and return portions are coupled by a thermally conductive material.

5. A heat sink or source apparatus as claimed in any preceding claim, wherein adjacent regions of the outward and/or return portion of the fluid passageway are separated by a thermally insulating material.

6. A heat sink or source apparatus as claimed in any preceding claim, wherein the return portion of the fluid passageway contacts the outward portion of the fluid passageway along its length.

7. A heat sink or source apparatus as claimed in any preceding claim, wherein the fluid passageway is formed by a tube.

8. A heat sink or source apparatus as claimed in claim 7 when appended to claim 4, wherein a wall of the tube forms the thermally conductive material.

9. A heat sink or source apparatus as claimed in any of claims 1 to 6, wherein a partition wall separates and partly defines the outward portion of the fluid passageway and the return portion of the fluid passageway.

10. A heat sink or source apparatus as claimed in claim 8 or 9, wherein the partition wall forms the thermally conductive material.

11. A heat sink or source apparatus as claimed in any preceding claim, wherein the outward and return portions are non-planar.

12. A heat sink or source apparatus as claimed in any preceding claim, wherein the paths of the outward and return portions are helical.

13. A heat sink or source apparatus as claimed in claim 12, wherein the helical paths of the outward and return portions comprise at least one turn.

14. A heat sink or source apparatus as claimed in any of claims 12 or 13, wherein the outward and return portions of the fluid passageway are partly defined by helicoid flights.

15. A heat sink or source apparatus as claimed in any preceding claim, wherein the wall thermally coupled to the fluid passageway defines an internal passageway which is configured to receive the component.

16. A heat sink or source apparatus as claimed in any preceding claim, wherein the wall thermally coupled to the fluid passageway is formed by an outer wall of the heat sink or source apparatus, wherein the heat sink or source apparatus is configured to be received within the component.

17. A heat sink or source apparatus according to any preceding claim, wherein the wall thermally coupled to the fluid passageway is cylindrical.

18. A heat sink or source apparatus as claimed in any of claims 1 to 10, wherein the outward and return portions of the fluid passageway are planar.

19. A heat sink or source apparatus as claimed in any preceding claim, wherein the fluid passageway forms the wall thermally coupled to the fluid passageway.

20. A heat sink or source apparatus for cooling or heating a component substantially as described herein with reference to the accompanying drawings.

21. A method of cooling or heating a component using the apparatus of any preceding claim, the method comprising: placing the component against the conduction surface of the apparatus; and passing a fluid through the fluid passageway such that it passes from the inlet to the outlet via the outward and return portions; wherein the temperatures of the outward portion are offset by the temperatures of the return portion such that the component is exposed to a substantially constant temperature along the length of the conduction surface.

22. A method of heating or cooling an apparatus as claimed in claim 21 and substantially as described herein.