EP4674721A1

EP4674721A1 - Cooling device for cooling a power unit of a railway vehicle, associated cooling assembly and railway vehicle

Info

Publication number: EP4674721A1
Application number: EP24306121.5A
Authority: EP
Inventors: Christophe AUDEMAR; Ines LATAPY
Original assignee: Alstom Holdings SA
Current assignee: Alstom Holdings SA
Priority date: 2024-07-05
Filing date: 2024-07-05
Publication date: 2026-01-07

Abstract

Cooling assembly (14) of a railway vehicle (10) comprising :
- a box (11) comprising a power unit (12) comprising a heat exchanger (16),
a cooling device (20) comprising a cooling circuit (26), configured for being filled with the heat exchanging fluid (C), a set (S1) of first fins, each first fins being configured for being arranged parallel to a displacement direction of the railway vehicle and a set (S2) of second fins, each second fins being perpendicular to the first fins,
- at least one parapet (18), extending along an elongation direction and, the cooling circuit being arranged within the parapet and the first fins being arranged parallel to the elongation direction.
- a piping (22), connecting the heat exchanger to the cooling device.

Description

The present invention relates to a cooling device for cooling a power unit of a railway vehicle. The present invention also relates to cooling assembly comprising such a cooling device and to a vehicle comprising such a cooling assembly.
In the domain of railway vehicles, it is known that power units require cooling to function properly and safely. To that end, cooling devices are generally used in order for the power units to be cooled.
Most of cooling devices rely on forced convection in order to cool the power units of railway vehicles. To that end, such devices comprise fans, which move air around the power unit in order to ensure cooling of the power unit.
Such devices are however not entirely satisfying. Indeed the fans used in such devices require energy in order to work properly, which is not cost effective. Furthermore, because of the use of fans, such cooling devices are generally noisy which can disrupt the surroundings or the inside of the railway vehicle. Finally, such devices are generally bulky and are exposed to failures, which can in turns impact on the operation of railway vehicles.
One of the goal of the present invention is thus to obtain a reliable, passive and cost effective cooling device which operation is quiet.
To that end, the invention relates to a cooling device for cooling a power unit of a railway vehicle, the cooling device comprising:

a cooling circuit, configured for being filled with a heat exchanging fluid,
a set of first fins, each first fins being configured for being arranged parallel to a displacement direction of the railway vehicle, and

a set of second fins, each second fins being perpendicular to the first fins.

Such a cooling device is especially advantageous since the fins of the first set of fins are configured to be arranged parallel to a relative wind resulting from the displacement of the railway vehicle. Thus, such a device allows exploiting the displacement of the vehicle on which the device is installed to force conversion at the first fins. The second fins also allow for dissipating heat with natural convection, for example when the railway vehicle on which is installed the device is not moving.
The cooling device according to the invention may include one or more of the following features, considered alone or according to any technically possible combination(s):

the first fins are parallel between them and the second fins are parallel between them,
the cooling circuit is arranged between the set of first fins and the set of second fins,
the cooling circuit comprises a first cooling loop, configured to exchange heat with the first set of fins, and a second cooling loop, configured to exchange heat with the second set of fins, the cooling device further comprising a wall, positioned between the first cooling loop and the second cooling loop and separating the first and second cooling loops,
the cooling device comprises a switch, configured for allowing fluidic circulation of the heat exchanging fluid in only one of the first and second cooling loops.

The present invention also relates to a cooling assembly comprising at least one parapet of a railway vehicle, extending along an elongation direction and comprising at least one cooling device as defined above, the cooling circuit being arranged within the parapet and the first fins being arranged parallel to the elongation direction.
The cooling device according to the invention may include one or more of the following features, considered alone or according to any technically possible combination(s):

the cooling assembly comprises a box, comprising a power unit comprising a heat exchanger, and a piping, connecting the heat exchanger to the cooling device,
the box comprises a plurality of power unit comprising heat exchangers, the heat exchangers being connected in parallel and/or in series to the cooling device.

The present invention also relates to a railway vehicle comprising a cooling assembly as defined above.
The invention will be better understood upon reading the following description, provided solely as an example, and in reference to the appended drawings, in which:

Figure 1 is a schematic front sectional view of a railway vehicle comprising a cooling device according to the invention;
Figure 2 is a schematic detailed view of the cooling device presented on figure 1;
Figure 3 is another schematic view, taken perpendicular to the view of figure 2, of the cooling device presented on figure 2;
Figure 4 is a schematic view similar to the view of figure 2, of another cooling device according to the invention; and
Figure 5 is a schematic view of a cooling arrangement comprising a cooling device as presented in figures 1 to 4.

With reference to figure 1, a railway vehicle 10 comprises a cooling assembly 14. The cooling assembly 14 comprises a box 11, for example a traction box, comprising a power unit 12, at least one cooling device 20 and a piping 22.
In the example of figure 5, the vehicle 10, and more specifically the cooling assembly 14 comprises a plurality of power units 12. In particular, in this example, the cooling assembly 14 comprises three power units 12.
Furthermore, as illustrated in figure 1, the cooling assembly 14 comprises for example a plurality of cooling devices 20. In particular, in the example of figure 1, the vehicle comprises two cooling devices 20. In the example of figure 5, only one cooling device 20 is represented for clarity purpose but the cooling assembly 14 presented in figure 5 may also comprise a plurality of cooling devices 20.
The railway vehicle 10 is for example a passenger railway vehicle such as a regional train, a high-speed train, a metro or a tramway. In other examples, the railway vehicle 10 is a freight transportation vehicle.
The railway vehicle 10 is for example elongated along a displacement direction D-D' of the vehicle, the vehicle 10 further being configured to travel along said displacement direction D-D'.
As visible from figure 1, the power unit 12 is for example arranged on a roof 15 of the vehicle 10, and more particularly in the box 11. In other non illustrated embodiments, the power unit 12 is arranged in or under the vehicle 10.
As illustrated from figure 1, the power unit 12 comprises for example a heat exchanger 16. The heat exchanger 16 is for example fluidically connected to the cooling device 20. To that end, the heat exchanger 16 for example defines a passage for a heat exchanging fluid C that is configured to circulate in said passage and in the cooling device 20. The piping 22 of the cooling assembly 14 for example fluidically connects the heat exchanger 16 to the cooling device 20 and is configured to guide the heat exchanging fluid C between the heat exchanger 16 and the cooling device 20. In the example presented in figure 5, the cooling assembly 14 comprises a plurality of power units 12 comprising heat exchangers 16. The heat exchangers 16 of these power units 12 are for example connected in parallel and/or in series to the cooling device 20.
As illustrated in figures 1 to 4, the cooling assembly 14 comprises a parapet 18, also named "acroteria", the parapet 18 being present for aesthetic reasons when the box 11, comprising the power unit 12, is arranged on the roof 15 of the vehicle 10. Advantageously, the parapet 18 comprises the cooling device 20. In other words, the cooling device 20 is integrated in the parapet 18.
As illustrated in figure 1, the parapet 18 is elongated along an elongation direction E-E'. The elongation direction E-E' is parallel to the displacement direction D-D'.
In the example of figure 1, the parapet 18 is arranged on a side of the roof 15 of the vehicle 10. In particular, in this example, the vehicle 10 comprises two parapets 18, the parapets 18 being arranged on opposed sides of the roof 15 of the vehicle 10.
As illustrated in figure 1, the parapet 18 is for example substantially flat and forms a wall portion protruding from the roof 15 of the railway vehicle 10. In a non-illustrated example, the parapet 18 extends for example in the continuity of a side panel 23 of the railway vehicle 10.
As illustrated from figure 1, and for example, a height H1 of the parapet 18, relative to the roof 15 is similar to the height H2 of the box 11, relative to the roof 15. In alternative, the height H1 of the parapet 18 differs from the height H2 of the box 11, and is for example greater or smaller than height H2 of the box 11.
In the example of figure 1 and 2, the parapet 18 is substantially inclined relative to the roof 15. In other non-illustrated embodiments, the parapet is for example curved around at least an axis extending parallel to the elongation direction E-E'.
In the example of figure 1 where the cooling assembly 14 comprises two cooling devices 20 respectively integrated in two parapets 18, the power unit 12 is arranged between the cooling devices 20.
The cooling device 20 is configured for cooling the power unit 12 of the railway vehicle. For example, and as exposed in more details later, the cooling device 20 is configured to cool the heat exchanging fluid C circulating in the piping 22 to and from the heat exchanger 16 of the power unit 12.
As visible from figures 1 to 3, the cooling device 20 comprises a cooling circuit 26, a set S1 of first fins 28 and a set S2 of second fins 30.
The cooling circuit 26 is configured to be filled with a heat exchanging fluid. For example, the cooling circuit 26 is configured to be filled with the same heat exchanging fluid C as the piping 22, the cooling circuit 26 being in fluidic communication with the piping 22.
The heat exchanging fluid C is for example an oil or water and for example glycolated water.
Advantageously, the cooling circuit 26 is arranged within the parapet 18.
The first set of fins S1 comprises for example between five and fifty first fins 28. As illustrated in figures 1 and 2, the first fins 28 are for example parallel between them.
A length of the first fins 28, that is the dimension of the first fins 28 along the displacement direction D-D', is for example comprised between 2m and 20m.
As this will be presented in more details later, the first fins 28 protrude preferably from the cooling circuit 26, and protrude for example away from the second fins 30 and/or away from the power unit 12.
The first fins 28 are configured to exchange heat, for example by conduction, with the heat exchanging fluid C circulating in the cooling circuit 26.
Each first fin 28, or in other words, each fin 28 of the first set of fins S1, is configured for being arranged parallel to the displacement direction D-D' of the railway vehicle. In particular, when the cooling device 20 is arranged on the railway vehicle 10, each first fin 28 is arranged parallel to the displacement direction D-D' of the railway vehicle. In other words, the normal of the first fins 28 is perpendicular to the displacement direction D-D', being understood that the normal of the fins 28 is defined as the normal to the main heat exchange surface of the fins 28.
The first fins 28 are then for example elongated along a first fin direction F1, which is for example substantially parallel to the parapet 18 and substantially parallel to the displacement direction D-D'.
The first fins 28 are for example substantially flat, and for example extend in a plane which is parallel to the displacement direction D-D' of the railway vehicle. As presented in the example of figures 1, 2 and 4, a tip of the first fins 28 is for example curved, for example towards the roof 15 of the vehicle 10.
The second set of fins S2 comprises for example between ten and one hundred second fins 30.
As illustrated in figures 3, the second fins 30 are for example parallel between them.
A length of the second fins 30, that is the longest the dimension of the second fins 30 along a direction perpendicular to the displacement direction D-D', is comprised for example between 10 cm and 50cm.
As presented in figure 1 and 2, the second fins 30 are for example arranged opposed to the first fins 28 relatively to the cooling circuit 26. The second set of fins S2 is for example connected to the cooling circuit 26.
As this will be presented in more details later, the second fins 30 protrude preferably from the cooling circuit 26, and protrude for example away from the first fins 28 and/or towards the power unit 12.
The second fins 30 are configured to exchange heat, for example by conduction, with the heat exchanging fluid C circulating in the cooling circuit 26.
Each second fin 30 is perpendicular to the first fins 28. As presented in figures 1 to 4 when the cooling device 20 is arranged on the vehicle 10, each second fin 30 is arranged perpendicular to the displacement direction D-D' of the railway vehicle 10. In other words, the normal of the second fins 30 is parallel to the displacement direction D-D', being understood that the normal of the fins 30 is defined as the normal to the main heat exchange surface of the fins 30.
The second fins 30 are then for example elongated along a second fin direction F2, which is perpendicular to the displacement direction D-D'. In particular, as visible in figures 1 and 2, the second fin direction F2 extends substantially parallel to the parapet 18. The second fin direction forms for example an angle A between 30° and 90° with the roof 15 of the vehicle 10.
The cooling circuit 26 is for example arranged between the set S1 of first fins 28 and the set S2 of second fins 30. For example, the cooling circuit 26 is arranged so that heat from the heat exchanging fluid C can be dissipated into ambient air through the first fins 28 and/or the second fins 30. In particular, the cooling circuit 26 is arranged so that heat from the heat exchanging fluid C is dissipated through the first fins 28 by forced convection resulting from the displacement of the vehicle 10 and from the second fins 30 by natural convection.
As illustrated from figure 2, the cooling circuit 26 is for example arranged within the parapet 18, the first set of fins S1 protruding from one side of the parapet 18 and the second set of fins protruding from another side, opposed to the first side, of the parapet 18.
The parapet 18 is then for example a profile, in which the cooling circuit 26 is formed. In other words, such a profile defines the cooling circuit 26. The profile forming the parapet 18 is for example made of aluminum.
In an embodiment, the first set of fins S1, the second set of fins S2 and the parapet 18 are formed integrally. In other embodiments, the first set of fins S1 and/or the second set of fins S2 are mounted on the parapet 18. The first fins 28 are arranged parallel to the elongation direction E-E'.
Figure 4 shows another embodiment of the cooling device, different from that shown in Figure 3. This embodiment differs from the embodiment presented in figure 3 only in the following respects. Analogous elements bear the same references.
In this embodiment, the cooling circuit 26 comprises a first cooling loop 32 and a second cooling loop 34. In this embodiment, the cooling device 20 further comprises a wall 36. The cooling device 20 further comprises for example a switch 38.
The first cooling loop 32 is configured to exchange heat with the first set of fins S1. To that end the first cooling loop 32 is for example directly connected to the first set of fins S1.
The second cooling loop 34 is configured to exchange heat with the second set of fins S2. To that end, the second cooling loop 34 is for example directly connected to the second set of fins S2.
The first cooling loop 32 and the second cooling loop 34 are for example arranged within the parapet 18, as illustrated in figure 4.
The first cooling loop 32 and the second cooling loop 34 are for example distinct, such that there is no fluidic exchange between the first cooling loop 32 and the second cooling loop 34. In particular, as illustrated in figure 4, the wall 36 extends between the first 32 and second 34 cooling loops. As presented in figure 4, the wall 36 is for example a portion of the parapet 18 arranged between the first 32 and second 38 cooling loops.
As presented in figure 4, the switch 38 is for example configured for allowing fluidic circulation of the heat exchanging fluid in only one of the first 32 and second cooling loop 34. In other words, the switch 38 is configured for connecting the piping 22 with only one of the first 32 and second 34 cooling loops such that the cooling fluid C circulates from the power unit 12 to either the first cooling 32 loop or the second cooling loop 34.
An operation of the above presented cooling device 20 will now be described.
The heat exchanging fluid C circulates in the cooling assembly 14 and in particular between the cooling device 20 and the power unit 12 in order to cool the power unit 12 down.
In particular, the heat exchanging fluid C is heated by the power unit 12 and is guided by the piping 22 to the cooling device 20.
The heat exchanging fluid C is then cooled in the cooling device 20. In particular the heat exchanging fluid C exchanges heat by conduction to the first 28 and/or second fins 30. The first 28 and/or second fins 30 then exchange heat with ambient air. This allows cooling of the heat exchanging fluid C.
The first fins 28 exchange heat with the ambient air mostly when the railway vehicle 10 is moving along the displacement direction D-D'. In particular, the air circulates between the first fins 28 due to the relative wind resulting from the displacement of the vehicle 10, resulting in forced convection cooling of the first fins 28.
The second fins 30 exchange heat with the ambient air mostly by natural convection. In particular, the ambient air is heated between the second fins 30, which provokes the rise of the ambient air and renewing of the air between the second fins 30, which ensure a proper cooling of the second fins 30.
In the embodiment presented in figure 4 where the cooling circuit comprises a first cooling loop 32, a second cooling loop 34 and a switch 38, the switch 38 is for example configured to be operated as a function of an operational status of the vehicle 10. To that end, the cooling device 20 comprises for example a control module configured to actuate the switch 38 as a function of the operational status of the vehicle 10.
For example, the switch 38 is actuated to allow fluidic circulation of the heat exchanging fluid C only in the second cooling loop 34 when the speed of the vehicle 10 is under a predetermined speed limit and/or when the vehicle 10 is stopped.
The switch 38 is for example actuated to allow fluidic circulation of the heat exchanging fluid C only in the first cooling loop 32 when the speed of the vehicle 10 is equal or above a predetermined speed limit and/or when the vehicle 10 is moving.
As seen above, having first fins 28 which are configured to be arranged parallel to the displacement direction D-D' allows reliable, cost effective and quiet cooling when the vehicle 10 is moving and having second fins which are perpendicular to the first fins allows reliable, cost effective and quiet cooling when the vehicle is not moving.
Having first fins 28 which are parallel between them and second fins 30 which are parallel between them allows a proper cooling since these fins 28, 30 define between them regular channels.
The use of different cooling loops 32, 34 and in particular in combination with a switch 38, allows adapting the cooling to the operation of the vehicle 10, for example taking advantage of relative wind along the first fins 28 when the vehicle 10 is moving and of natural convection along the second fins 30 when the vehicle 10 is stopped.
Having the first set of fins S1 arranged between the parapet 18 and the second set of fins S2 allows a good guiding of the ambient air between the first fins 28 when the vehicle is moving. Furthermore, this can for example ensure that the second fins 30 are protected from the sun, to allow a proper cooling through these fins 30 when the vehicle is not moving.

Claims

Cooling device (20) for cooling a power unit (12) of a railway vehicle (10), the cooling device (20) comprising:
- a cooling circuit (26), configured for being filled with a heat exchanging fluid (C),

- a set (S1) of first fins (28), each first fins (28) being configured for being arranged parallel to a displacement direction (D-D') of the railway vehicle (10), and

- a set (S2) of second fins (30), each second fins (30) being perpendicular to the first fins (28).
Cooling device (20) according to claim 1, wherein the first fins (28) are parallel between them and the second fins (30) are parallel between them.
Cooling device (20) according to claim 1 or 2, wherein the cooling circuit (26) is arranged between the set (S1) of first fins (28) and the set (S2) of second fins (30).
Cooling device (20) according to any of the previous claims, wherein the cooling circuit (26) comprises a first cooling loop (32), configured to exchange heat with the first set of fins (S1), and a second cooling loop (34), configured to exchange heat with the second set of fins (S2), the cooling device (20) further comprising a wall (36), positioned between the first cooling loop (32) and the second cooling loop (34) and separating the first (32) and second (34) cooling loops.
Cooling device (20) according to claim 4, wherein the cooling device (20) comprises a switch (38), configured for allowing fluidic circulation of the heat exchanging fluid (C) in only one of the first (32) and second (34) cooling loops.
Cooling assembly (14) comprising at least one parapet (18) of a railway vehicle (10), extending along an elongation direction (E-E') and comprising at least one cooling device (20) according to any of the previous claims, the cooling circuit (26) being arranged within the parapet (18) and the first fins (28) being arranged parallel to the elongation direction (E-E').
Cooling assembly (14) according to claim 6 comprising :
- a box (11) comprising a power unit (12) comprising a heat exchanger (16),

- a piping (22), connecting the heat exchanger (16) to the cooling device (20).
Cooling assembly (14) according to claim 7, wherein the box (11) comprises a plurality of power unit (12) comprising heat exchangers (16), the heat exchangers (16) being connected in parallel and/or in series to the cooling device (20).
Railway vehicle (10), comprising a cooling assembly (14) according to claim 7 or 8.