ELECTRIC ARRANGEMENT, PANEL AND HEAT EXCHANGER

Abstract

An electric arrangement comprising a casing; a heat generating electric component arranged inside the casing; and a heat exchanger comprising a three dimensional lattice cell structure, the three dimensional lattice cell structure being arranged to conduct a dielectric cooling fluid from the casing at an exterior side of the casing for heat exchange with an ambient fluid, and back towards the casing for cooling of the electric component. A panel for a heat exchanger and a heat exchanger comprising a plurality of panels are also provided.

Claims

1. An electric arrangement comprising: a casing; a heat generating electric component arranged inside the casing; and a heat exchanger comprising a three dimensional lattice cell structure, the three dimensional lattice cell structure being arranged to conduct a dielectric cooling fluid from the casing at an exterior side of the casing for heat exchange with an ambient fluid, and back towards the casing for cooling of the electric component.

2. The electric arrangement according to claim 1, wherein the heat exchanger comprises a plurality of bodies, each body comprising a three dimensional lattice cell structure or a two dimensional lattice structure.

3. The electric arrangement according to claim 2, wherein each body is detachably connected to the casing.

4. The electric arrangement according to claim 2, wherein each body is a panel comprising a two dimensional lattice cell structure.

5. The electric arrangement according to claim 4, wherein the panels are arranged in a stack to form the three dimensional lattice cell structure.

6. The electric arrangement according to claim 1, wherein the three dimensional lattice cell structure comprises a triply periodic substantially minimal surface.

7. The electric arrangement according to claim 1, wherein the three dimensional lattice cell structure comprises non-flat and flow-promoting ends.

8. The electric arrangement according to claim 1, wherein the heat exchanger comprises two three dimensional lattice cell structures arranged in parallel, and wherein each three dimensional lattice cell structure is arranged to conduct the cooling fluid from the casing at the exterior side of the casing for heat exchange with an ambient fluid, and back towards the casing for cooling of the electric component.

9. The electric arrangement according to claim 1, wherein the heat exchanger further comprises pipes for conducting the ambient fluid through the three dimensional lattice cell structure.

10. The electric arrangement according to claim 1, wherein the heat exchanger comprises a guiding structure inside the three dimensional lattice cell structure, the guiding structure being arranged to guide the cooling fluid along a defined path inside the three dimensional lattice cell structure.

11. The electric arrangement according to claim 1, further comprising a pump arrangement arranged to generate a flow of the cooling fluid through the three dimensional lattice cell structure.

12. The electric arrangement according to claim 1, further comprising a fan arrangement arranged to generate a flow of the ambient fluid in the three dimensional lattice cell structure.

13. The electric arrangement according to claim 12, wherein the fan arrangement is arranged to generate a flow of the ambient fluid in the three dimensional lattice cell structure in at least two different directions.

14. The electric arrangement according to claim 1, wherein the electric arrangement is a high voltage static electric induction system, such as a power transformer or a shunt reactor.

15. A panel for a heat exchanger, the panel comprising an inlet, an outlet and a two dimensional lattice cell structure fluidly between the inlet and the outlet.

16. A heat exchanger for an electric arrangement, the heat exchanger comprising a plurality of panels according to claim 15, the panels being arranged in a stack to form a three dimensional lattice cell structure.

17. The heat exchanger according to claim 16, wherein the three dimensional lattice cell structure is arranged to conduct a dielectric cooling fluid from a casing at an exterior side of the casing for heat exchange with an ambient fluid, and back towards the casing for cooling of a heat generating electric component.

18. The heat exchanger according to claim 16, wherein the three dimensional lattice cell structure comprises non-flat and flow-promoting ends.

19. The heat exchanger according to claim 16, wherein the heat exchanger further comprises pipes for conducting the ambient fluid through the three dimensional lattice cell structure.

20. The heat exchanger according to claim 16, wherein the heat exchanger further comprises a guiding structure inside the three dimensional lattice cell structure, the guiding structure being arranged to guide the cooling fluid along a defined path inside the three dimensional lattice cell structure.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Further details, advantages and aspects of the present disclosure will become apparent from the following embodiments taken in conjunction with the drawings, wherein:

[0041] FIG. 1: schematically represents a side view of an electric arrangement comprising a heat exchanger;

[0042] FIG. 2: schematically represents a partial perspective view of a three dimensional lattice cell structure of the heat exchanger in FIG. 1;

[0043] FIG. 3: schematically represents a side view of an electric arrangement comprising a further example of heat exchanger;

[0044] FIG. 4: schematically represents a partial perspective view of the heat exchanger in FIG. 3;

[0045] FIG. 5: schematically represents a side view of an electric arrangement comprising a further example of heat exchanger;

[0046] FIG. 6: schematically represents a side view of an electric arrangement comprising a further example of heat exchanger;

[0047] FIG. 7: schematically represents a side view of an electric arrangement comprising a further example of heat exchanger;

[0048] FIG. 8: schematically represents a perspective view of a panel of the heat exchanger in FIG. 7;

[0049] FIG. 9: schematically represents a front view of the panel in FIG. 8;

[0050] FIG. 10: schematically represents a side view of an electric arrangement comprising a further example of heat exchanger; and

[0051] FIG. 11: schematically represents a front view of the electric arrangement in FIG. 10.

DETAILED DESCRIPTION

[0052] In the following, an electric arrangement comprising a heat exchanger, a panel for a heat exchanger, and a heat exchanger comprising a plurality of panels, will be described. The same or similar reference numerals will be used to denote the same or similar structural features.

[0053] FIG. 1 schematically represents a side view of a power transformer 10 comprising a heat exchanger 12. The power transformer 10 is one example of an electric arrangement. The power transformer 10 comprises a casing 14. The casing 14 contains dielectric oil 16. Dielectric oil 16 is one example of a dielectric cooling fluid.

[0054] The power transformer 10 further comprises an electric component 18. The electric component 18 is arranged inside the casing 14. The electric component 18 is submerged in the oil 16. The electric component 18 generates heat during operation of the power transformer 10. The electric component 18 may for example be a winding of the power transformer 10.

[0055] FIG. 1 further indicates ambient air 20 outside the casing 14. The air 20 may be the atmosphere. The air 20 is one example of an ambient fluid.

[0056] The heat exchanger 12 comprises a three dimensional lattice cell structure 22. The three dimensional lattice cell structure 22 comprises a plurality of cells 24. The three dimensional lattice cell structure 22 of this example comprises a triply periodic substantially minimal surface having an elongated Schwarz P surface. The three dimensional lattice cell structure 22 may be for example be 3D printed.

[0057] The three dimensional lattice cell structure 22 defines an interior lattice cell structure volume 26 and an exterior lattice cell structure volume 28. The interior lattice cell structure volume 26 and the exterior lattice cell structure volume 28 constitute two separate networks. Oil 16 from the interior of the casing 14 can flow into and out from the interior lattice cell structure volume 26. The air 20 can flow into and out from the exterior lattice cell structure volume 28. In this example, each of the interior lattice cell structure volume 26 and the exterior lattice cell structure volume 28 is continuous.

[0058] The three dimensional lattice cell structure 22 is thus configured to conduct the oil 16 from the casing 14 to an exterior side of the casing 14 and back towards the casing 14. The three dimensional lattice cell structure 22 comprises large surface areas for heat exchange between the oil 16 and the air 20. Tests have shown that the heat exchanger 12 has a very high heat transfer coefficient. A number of radiators can thereby be reduced. Despite the large surface areas for heat exchange, the three dimensional lattice cell structure 22 is also compact.

[0059] The heat exchanger 12 comprises an inlet 30 and an outlet 32. Each of the inlet 30 and the outlet 32 is arranged fluidly between the casing 14 and the three dimensional lattice cell structure 22. The inlet 30 is arranged geodetically higher than the outlet 32.

[0060] As shown in FIG. 1, the casing 14 and the three dimensional lattice cell structure 22 define a circuit for the oil 16 comprising the casing 14, the inlet 30, the three dimensional lattice cell structure 22 and the outlet 32. In FIG. 1, the oil 16 flows in this circuit in a clockwise direction during operation of the power transformer 10, as indicated with arrows. That is, the oil 16 is heated by the electric component 18. The hot oil 16 then enters the three dimensional lattice cell structure 22 through the inlet 30. The hot oil 16 in the interior lattice cell structure volume 26 is then cooled by heat exchange with the air 20 in the exterior lattice cell structure volume 28. Cold oil 16 then exits the three dimensional lattice cell structure 22 through the outlet 32. The electric component 18 is then cooled by the cold oil 16.

[0061] The casing 14 comprises four side walls 34 and a top wall 36. In the example in FIG. 1, the three dimensional lattice cell structure 22 is embedded in one of the side walls 34. The three dimensional lattice cell structure 22 may for example be welded or bolted to the side wall 34.

[0062] The power transformer 10 further comprises a fan arrangement. The fan arrangement comprises a front fan 38 and a bottom fan 40. The front fan 38 is configured to blow the air 20 horizontally into the three dimensional lattice cell structure 22. The bottom fan 40 is configured to blow the air 20 vertically into the three dimensional lattice cell structure 22 from below. The cooling efficiency of the power transformer 10 can easily be regulated by adjusting the speeds of the fans 38, 40. The fan arrangement may also comprise a further fan (not shown) that blows the air 20 in a further horizontal direction, perpendicular to the blowing direction of the front fan 38.

[0063] The three dimensional lattice cell structure 22 further comprises non-flat and flow-promoting ends 42. Each end 42 closes a respective cell 24 of the three dimensional lattice cell structure 22.

[0064] FIG. 2 schematically represents a partial perspective view of the three dimensional lattice cell structure 22 of the heat exchanger 12 in FIG. 1. As shown in FIG. 2, the three dimensional lattice cell structure 22 comprises a periodic pattern in each of three orthogonal directions. Each periodic pattern comprises a plurality of periods. The cells 24 are arranged orthogonally in three directions. As shown in FIG. 2, each non-flat and flow-promoting end 42 of this example has a shape of a cone.

[0065] FIG. 3 schematically represents a side view of a power transformer 10 comprising a further example of heat exchanger 12 and FIG. 4 schematically represents a partial perspective view of the heat exchanger 12 in FIG. 3. With collective reference to FIGS. 3 and 4, mainly differences with respect to FIGS. 1 and 2 will be described.

[0066] The heat exchanger 12 in FIGS. 3 and 4 comprises a plurality of pipes 44. In this example, each pipe 44 is straight and vertically oriented. The pipes 44 are configured to guide the air 20 through the three dimensional lattice cell structure 22.

[0067] Each pipe 44 extends through the entire three dimensional lattice cell structure 22. In this example, each pipe 44 extends through the cells 24 of the three dimensional lattice cell structure 22.

[0068] The heat exchanger 12 in FIG. 3 further comprises a manifold 46. The manifold 46 branches into the pipes 44. The bottom fan 40 is arranged to blow air 20 through the pipes 44 via the manifold 46. The front fan 38 is arranged to blow air 20 into the three dimensional lattice cell structure 22 in the same manner as in FIG. 1. Thus, in FIG. 3, heat exchange between the oil 16 and the air 20 takes place both between the interior lattice cell structure volume 26 and the exterior lattice cell structure volume 28 and between the interior lattice cell structure volume 26 and the pipes 44. In this way, heat transfer efficiency between the oil 16 and the air 20 is further increased. The heat exchanger 12 in FIG. 3 also has a simple structure.

[0069] The pipes 44 in FIGS. 3 and 4 may alternatively be configured as heat pipes containing two-phase coolant and provided with an interior capillary structure. In this case, the pipes 44 may extend further outside the three dimensional lattice cell structure 22.

[0070] FIG. 5 schematically represents a side view of a power transformer 10 comprising a further example of heat exchanger 12. Mainly differences with respect to FIGS. 1 and 2 will be described.

[0071] The heat exchanger 12 in FIG. 5 further comprises a plurality of plates 48. The plates 48 define a path 50 inside the interior lattice cell structure volume 26. As shown in FIG. 5, the path 50 is serpentine-shaped. The plates 48 are one example of a guiding structure for guiding the oil 16 inside the three dimensional lattice cell structure 22.

[0072] As shown in FIG. 5, the plates 48 force the oil 16 to a distal (with respect to the casing 14) region of the three dimensional lattice cell structure 22. The plates 48 thereby further improve heat transfer between the oil 16 and the air 20 in the three dimensional lattice cell structure 22.

[0073] FIG. 6 schematically represents a side view of a power transformer 10 comprising a further example of heat exchanger 12. Mainly differences with respect to FIGS. 1 and 2 will be described.

[0074] The heat exchanger 12 in FIG. 6 comprises a plurality of bodies 52. Each body 52 comprises a three dimensional lattice cell structure 22. The bodies 52 thus form a plurality of parallel networks for the oil 16. Each three dimensional lattice cell structure 22 is configured to conduct the oil 16 from the casing 14 at the exterior side of the casing 14 for heat exchange with the air 20, and back towards the casing 14 for cooling the electric component 18.

[0075] Each body 52 is detachably connectable to the casing 14. The power transformer 10 can function even when one of the bodies 52 is removed for replacement. In this case, openings into the body 52 removed for replacement need to be closed. Replacement of only one body 52 is simpler and cheaper.

[0076] The bodies 52 do however not need to be directly connectable to the casing 14. As shown in FIG. 6, the heat exchanger 12 comprises an upper manifold 54 and a lower manifold 56. The upper manifold 54 branches into the inlet 30 of each body 52. The outlet 32 of each body 52 are joined by the lower manifold 56. Each body 52 is detachably connectable to the upper manifold 54 and the lower manifold 56.

[0077] The power transformer 10 in FIG. 6 further comprises a pump 58. The pump 58 constitutes one example of a pump arrangement. The pump 58 is configured to selectively enhance a flow of the oil 16 through the three dimensional lattice cell structure 22. The cooling efficiency of the power transformer 10 can easily be regulated by adjusting the speed of the pump 58. In the example in FIG. 6, the pump 58 is arranged in the lower manifold 56, i.e., downstream of the bodies 52.

[0078] The power transformer 10 in FIG. 6 further comprises a plurality of bottom fans 40. Each bottom fan 40 is arranged below one of the three dimensional lattice cell structure 22. One bottom fan 40 is associated with each three dimensional lattice cell structure 22.

[0079] FIG. 7 schematically represents a side view of a power transformer 10 comprising a further example of heat exchanger 12. The heat exchanger 12 comprises a plurality of panels 60. FIG. 8 schematically represents a perspective view of one of the panels 60 of the heat exchanger 12 in FIG. 7, and FIG. 9 schematically represents a front view of the panel 60 in FIG. 8. With collective reference to FIGS. 7-9, mainly differences with respect to FIG. 6 will be described.

[0080] The panels 60 are further examples of bodies according to the present disclosure. Each panel 60 is detachably connectable to the casing 14. Each panel 60 comprises a two dimensional lattice cell structure 62. Furthermore, each panel 60 in this example comprises a plurality of holes 64. The holes 64 are arranged between the cells 24.

[0081] The panels 60 are arranged in a stack. In this way, the panels 60 jointly form a three dimensional lattice cell structure 22. The distance between the panels 60 may be varied, e.g., optimized for an improved heat transfer. As shown in FIG. 7, each panel 60 is horizontally oriented. In the example in FIGS. 7-9, the interior lattice cell structure volume 26 is discontinuous. The three dimensional lattice cell structure 22 thus forms a plurality of parallel labyrinth networks for the oil 16, i.e., one network in each panel 60.

[0082] By means of the holes 64, the exterior lattice cell structure volume 28 is continuous. However, the panel 60 does not need to comprise the holes 64, for example if the panel 60 is made of sheet metal. In this case, the exterior lattice cell structure volume 28 would be discontinuous between the panels 60.

[0083] The panels 60 are arranged in a dense configuration. In this example, the panels 60 are overlapping. That is, cells 24 of one panel 60 enter into respective spaces between cells 24 of an adjacent panel 60. Thus, the cells 24 of adjacent panels 60 are offset.

[0084] As an alternative, the non-flat ends 42 of the panels 60 may be replaced with flat ends. In this case, the panels 60 may be compactly arranged face-to-face with each other and the cells 24 of adjacent panels 60 do not need to be offset.

[0085] The heat exchanger 12 further comprises a conduit 66. The outlet 32 of each panel 60 is connected to the conduit 66. The conduit 66 transitions (as seen in the flow direction of the oil 16) from vertical to horizontal prior to connecting to the casing 14. The pump 58 is arranged in the conduit 66, here in the vertical section thereof. The bottom fan 40 is arranged vertically between the three dimensional lattice cell structure 22 and the horizontal section of the conduit 66.

[0086] The panel 60 according to FIGS. 8 and 9 is merely one specific example. In particular, the design of the inlet 30 and the outlet 32 may be modified.

[0087] FIG. 10 schematically represents a side view of a power transformer 10 comprising a further example of heat exchanger 12 and FIG. 11 schematically represents a front view of the power transformer 10 in FIG. 10. With collective reference to FIGS. 10 and 11, mainly differences with respect to FIG. 7 will be described.

[0088] The panels 60 used in FIGS. 10 and 11 are of the same type as in FIGS. 8 and 9. As shown in FIGS. 10 and 11, each panel 60 is vertically oriented. The panels 60 are arranged in a stack to jointly form a three dimensional lattice cell structure 22.

[0089] FIG. 11 further shows that the fan arrangement comprises two further fans 68. Each fan 68 is arranged to blow the air 20 into the three dimensional lattice cell structure 22 in a horizontal direction, perpendicular to the blowing direction of the front fan 38.

[0090] While the present disclosure has been described with reference to exemplary embodiments, it will be appreciated that the subject matter as claimed is not limited to what has been described above. For example, it will be appreciated that the dimensions of the parts may be varied as needed. Accordingly, it is intended that the subject matter as claimed may be limited only by the scope of the claims appended hereto.