FIELD OF THE INVENTION

The present invention relates to a heating and/or cooling system for heating and/or cooling of a railway track.

BACKGROUND OF THE INVENTION

Heating of railway tracks and switches is commonly used for melting ice and snow in winter conditions. There are many heating systems known in the prior art. Many of these heating systems employ heating with electricity or gas.

Recent developments have focused on reducing energy consumption to reduce cost and impact on the environment.

The European Patent EP2260149B1 discloses a heating system for heating switching rails, wherein a heating line through which fluid flows with at least one wall is in heat-conducting contact with a rail part and connected to a line system, which preferably draws heat from a circulating fluid, and to a corresponding assembly method. From the switch start, the stock rail of a switch tongue device is contacted on the outside on the web with a metal molded piece, which on the side facing away from the web preferably comprises two holders for the flow line to be clamped and the return of the heating line. In addition, the tongue blade is installed on the side facing away from the stock rail and at a distance from the switch start.

The European Patent EP1262597B1 discloses a method for heating and/or cooling a rail element, wherein heating liquid is carried along the rail element, wherein heat transfer takes place between the liquid and the rail element, wherein the relatively high temperature or low temperature of the liquid is obtained by extracting heat respectively cold from the ground.

The present invention aims at simplifying the installation of rail heating systems and improving the heat transfer and efficiency from the heating element to the railway track.

SUMMARY OF THE INVENTION

The present invention relates to a heating and/or cooling system for heating and/or cooling of a railway track, wherein the heating and/or cooling system comprises:

- a heat transfer element,

- a heat exchanger connectable to a heat or cooling source, wherein the system comprises a pump and fluid lines for circulating fluid between the heat exchanger and the heat transfer element, wherein the heat transfer element is provided in thermal contact with a web of the railway track, characterized in that the heat transfer element comprises a metal profile, wherein the metal profile comprises a first duct in which the fluid is circulated within the metal profile, wherein the metal profile comprises ribs protruding into the first duct.

In one aspect, the heat transfer element is provided in direct thermal contact with the railway track. Alternatively, the heat transfer element is provided in indirect thermal contact with the railway track, for example via a thermal paste, or another type of thermal material able to establish a good thermal contact between an, in some cases, uneven surface of the railway track and the heat transfer element.

According to the above duct, the fluid is in direct contact with the metal profile. Hence, a simple solution for efficient heat transfer is achieved.

According to the above, the ribs increase the surface of the duct. Hence, it is achieved an efficient thermal transfer between the fluid and the metal profile and further between the metal profile and the web of the rail.

In one aspect, the first duct is a heat transferring duct. This first heat transferring duct has the purpose of transferring heat between the fluid in the first duct and the web of the railway track via the metal profile.

In one aspect the heat transfer element is configured to transfer heat to the railway track and hereby heating the railway track by circulating the fluid with a fluid temperature higher than the ambient temperature of the railway track.

In one aspect the heat transfer element is configured to transfer heat from the railway track and hereby cooling the railway track by circulating the fluid with a fluid temperature lower than the ambient temperature of the railway track.

In one aspect, the ribs are protruding from a web-facing side of the metal profile into the first duct.

According to the location of the ribs, the heat transfer between the fluid and the metal profile is increased at the web-facing side of the heat transfer element.

In one aspect, a height of the first duct is at least 80% of the total height of the metal profile. In one aspect, the height of the first duct is at least 75% of the height of a web of the railway track.

In one aspect, the metal profile comprises a second duct in which the fluid is circulated within the metal profile, and wherein the metal profile comprises ribs protruding into the duct.

In one aspect, the second duct is also a heat transferring duct. This second heat transferring duct has the primary purpose of transferring heat between the fluid in the second duct and the web of the railway track via the metal profile.

In one aspect, the ribs are protruding from the web-facing side of the metal profile into the second duct.

In one aspect, the sum of the height of the first duct and the height of the second duct is at least 75% of the total height of the metal profile.

In one aspect, the metal profile is provided as an extruded aluminium profile, wherein the shape of the cross-section of the heat transfer element is the same in the longitudinal direction of the heat transfer element.

In one aspect, the metal profile comprises a further duct provided on the opposite side of the web-facing side.

In one aspect, the further duct is a supplying duct. This supplying duct has the primary purpose of supplying fluid from the supplying duct to the first duct and/or to the second duct.

Alternatively, the further duct is an insulation duct. This insulation duct may be filled with a gas, such as air, or it may be filled with an insulation material.

In one aspect, the cross-sectional area of the further duct is at least 60% larger than the cross-sectional area of the first duct.

According to the above, a preferable temperature and flow direction is achieved within the ducts by the cross-sectional area of the further duct being larger than the cross-sectional area of the first duct.

In one aspect, the cross-sectional area of the further duct is at least 60% larger than the sum of the cross-sectional area of the first duct and the cross-sectional area of the second duct.

According to the above, a preferable temperature and flow direction is achieved within the ducts by the cross-sectional area of the further duct being larger than the sum of the cross-sectional area of the first duct and the cross-sectional area of the second duct. In one aspect, the heating and/or cooling system comprises:

- a further heat transfer element similar to the heat transfer element comprising a metal profile provided in thermal contact with a web of the railway track;

- a joint for transferring fluid between the heat transfer element and the further heat transfer element.

In one aspect, the joint is fluidly connecting the first duct, the second duct and/or the further duct of the heat transfer element with the respective first duct, the respective second duct and/or the respective further duct of the further heat transfer element.

The further heat transfer element is similar to the heat transfer element in that the cross-sectional shape of the elements are identical to each other. However, as the length of the railway track may vary, one of the heat transfer elements may be cut to a suitable length. Therefore, the further heat transfer element may have a different length than the heat transfer element.

In one aspect, the joint comprises:

- a first adapter connected to a second end of the heat transfer element,

- a second adapter connected to a first end of the further heat transfer element,

- a fluid connector for providing fluid communication between the first adapter and the second adapter.

In one aspect, the fluid connector is a flexible hose.

In one aspect, when the heat transfer element and the further heat transfer element comprise more than one duct, the fluid connector may provide separate fluid communications between the ducts, or the fluid connector may provide a common fluid communication between the ducts.

In one aspect, the heat transfer element comprises a thermal insulation barrier provided on an outer surface of the metal profile, opposite to the web-facing side.

In one aspect, the outer surface of the metal profile opposite of the web-facing side together with a top surface of the metal profile are shaped as a deflector for precipitation and/or small particles.

In one aspect, the cross-section of the metal profile is generally P-shaped.

The P-shape of the metal profile facilitates mounting of the heat transfer element to the railway track without interfering with existing mountings or fittings of the railway track. DETAILED DESCRIPTION

Embodiments of the invention will now be described in detail with reference to the enclosed drawings, wherein:

Fig. 1 is a schematical overview showing a first embodiment of a heating and/or cooling system for heating and/or cooling of a railway track,

Fig. 2 is a cross-sectional view of a first embodiment of a heat transfer element and the railway track,

Fig. 3 is an enlarged ross sectional view of the first embodiment of the heat transfer element, Fig. 4 is a cross-sectional view of a second embodiment of the heat transfer element with the first and a second duct and the further duct; showing relationship between height of the ducts and total height of profile,

Fig 5 is a cross-sectional view of railway track with a third embodiment of the heat transfer element installed, Fig. 6a is a cross-sectional view of the first embodiment of the heat transfer element wherein the cross-sectional areas of the first duct and the further duct are illustrated,

Fig. 6b is a cross-sectional view of the second embodiment of the heat transfer element wherein the cross-sectional areas of the first duct, the second duct and the further duct are illustrated, Fig 7a is a perspective view of two heat transfer elements connected in series by means of a joint to a railway track,

Fig. 7b is a side view of fig. 7a,

Fig. 8 is a top cross-sectional view of the joint,

Fig 9 is a cross-sectional view of a fourth embodiment of the heat transfer element, Fig. 10a, 10b, 10c are different views of an alternative embodiment of the second adapter,

Fig. 1 la is a top cross-sectional view of an alternative embodiment of the joint,

Fig. 1 lb is a further top cross-sectional view of another alternative embodiment of the joint.

System for heating and/or cooling of a railway track Fig. 1 shows a heating and/or cooling system 1 for heating and/or cooling of a railway track 6 on railway sleepers 8. The heating and/or cooling system 1 comprises a heat transfer element 10, a heat exchanger 4 connectable to a heat or cooling source 2, a pump 5 and fluid lines 9 for circulating fluid between the heat exchanger 4 and the heat transfer element 10.

As shown in fig. 2, the heat transfer element 10 is provided in thermal contact with the web 7 of a railway track 6. The heat transfer element 10 is provided in direct or indirect thermal contact with the web 7 of the railway track 6. In fig. 3, the heat transfer element 10 is provided in indirect thermal contact with the railway track 6 by means of a thermal paste indicated by a dashed line 3.

The main focus of the present invention is heating of the railway track, and the embodiments described below will describe heating systems. However, the system may easily be configured as a cooling system.

The heat transfer element

As shown in fig. 3, the heat transfer element 10 comprises a metal profile 11 within which there is a first duct 20 for circulation of fluid. The metal profile 11 further comprises ribs 12 protruding into the first duct 20. The ribs 12 are protruding from the web-facing side 15 of the metal profile 11 into the first duct 20.

Fig. 4 shows a further embodiment of the heat transfer element 10 with a second duct 24 in which fluid is circulated within the metal profile 11. The metal profile 11 also comprises ribs 12, protruding into the second duct 24. The ribs 12 are protruding from the web-facing side 15 of the metal profile 11 into the second duct 24.

Figs. 3 and 4 show also that the metal profile 11 comprises a further duct 22 provided on the opposite side 16 of the web-facing side 15. The further duct 22 has no ribs as its function is to supply fluid to the first duct 20 and second duct 24, as will be apparent from the description below.

Also shown in fig. 3 is that the height H20 of the first duct 20 is at least 80% of the total height Htot of the metal profile 11.

Shown in fig. 4 is that the sum of the height H20 of the first duct 20 and the height H24 of the second duct 24 is at least 75% of the total height Htot of the metal profile 11.

Fig. 5 shows that the height H20 of the first duct 20 is at least 75% of the height Hw of a web 7 of the railway track 6.

The relationship between the cross-sectional areas of the ducts is shown in fig. 6a and fig. 6b. In fig 6a, the cross-sectional area A22 of the further duct 22 is at least 60% larger than the cross-sectional area A20 of the first duct 20. Shown in fig. 6b is that the cross-sectional area A22 of the further duct 22 is at least 60% larger than the sum of the cross-sectional area A20 of the first duct 20 and the cross-sectional area A24 of the second duct 24.

Figs 3 and 4 show that the outer surface 16 of the metal profile opposite of the web facing side 15 together with a top surface 18 of the metal profile 11 have a convex shape. This shape servers as a deflector for precipitation and/or small particles.

Figs 2 to 6b also show that the cross-sectional shape of the metal profile 11 is generally P-shaped. The P-shape of the metal profile 11 facilitates mounting of the heat transfer element 10 to the railway track 6 without interfering with existing mountings or fittings of the railway track 6.

The metal profile 11 of the heat transfer element is in the present embodiments provided as an extruded aluminum profile, wherein the shape of the cross-section of the heat transfer element 10 is the same in the longitudinal direction I-I of the heat transfer element 10.

Fluid flow and heat transfer in the heat transfer element

As shown in fig 2, the heat transfer element 10 comprises a metal profile 11, wherein the metal profile 11 comprises a first duct 20 in which the fluid is circulated within the metal profile 11. It is also shown in fig. 2 that the metal profile 11 comprises ribs 12 protruding into the first duct 20. The first duct 20 is a heat transferring duct. This first heat transferring duct 20 has the purpose of transferring heat between the fluid in the first duct 20 and the web 7 of the railway track 6 via the metal profile 11.

According to the above duct, the fluid is in direct contact with the metal profile 11. The ribs 12 increase the surface of the duct. Hence, it is achieved an efficient thermal transfer between the fluid and the metal profile and further between the metal profile 7 and the web of the rail 6.

As shown in fig. 4, that the metal profile 11 comprises a second duct 24 in which the fluid is circulated and with ribs 12 protruding into the second duct 24. The second heat transferring duct 24 has the primary purpose of transferring heat between the fluid in the second duct 24 and the web 7 of the railway track 6 via the metal profile 11.

It is shown in fig. 3 and fig. 4 that the ribs 12 are protruding from a web-facing side 15 of the metal profile 11 into the first duct 20 and into the second duct 24. According to the location of the ribs 12, the heat transfer between the fluid and the metal profile is increased at the web-facing side 15 of the heat transfer element 10. As shown in fig. 2, the metal profile 11 comprises a further duct 22 provided on the opposite side 16 of the web-facing side 15. The further duct 22 is a supplying duct, supplying fluid from the supplying duct 22 to the first duct 20 and/or to the second duct 24.

Fig. 6a shows that the cross-sectional area A22 of the further duct 22 being larger than the cross-sectional area A20 of the first duct 20. According to the above, a preferable temperature and flow direction is achieved within the ducts when the cross-sectional area A22 of the further duct is larger than the cross-sectional area A20 of the first duct.

Fig. 6b shows that the cross-sectional area A22 of the further duct 22 is larger than the sum of the cross-sectional area A20 of the first duct 20 and the cross-sectional area A24 of the second duct 24. According to the above, a preferable temperature and flow direction is achieved within the ducts by the cross-sectional area A22 of the further duct being larger than the sum of the cross-sectional area A20 of the first duct and the cross-sectional area A24 of the second duct.

In one aspect the heat transfer element 10 is configured to transfer heat to the railway track 6 and hereby heating the railway track 6 by circulating the fluid with a fluid temperature TF higher than the ambient temperature TA of the railway track 6.

In one aspect the heat transfer element 10 is configured to transfer heat from the railway track 6 and hereby cooling the railway track 6 by circulating the fluid with a fluid temperature TF lower than the ambient temperature TA of the railway track 6.

Joining heat transfer elements

As shown in fig. 7a and 7b, the heating and/or cooling system 1 comprises the above heat transfer element 10 and a further heat transfer element 10b. The further heat transfer element 10b is similar to the heat transfer element 10 comprising a metal profile 11 provided in thermal contact with a web 7 of the railway track 6.

The further heat transfer element 10b is similar to the heat transfer element 10 in that the cross-sectional shape of the elements 10, 10b are identical to each other. However, as the length of the railway track may vary, one of the heat transfer elements may be cut to a suitable length. Therefore, the further heat transfer element 10b may have a different length than the heat transfer element 10.

It is also shown in fig. 7a and 7b, that a joint 30 is provided for transferring fluid between the heat transfer element 10 and the further heat transfer element 10b.

Figs 7a and 7b also show that the joint 30 comprises a first adapter 26 connected to a second end of the heat transfer element 10, a second adapter 28 connected to a first end of the further heat transfer element 10b and a fluid connector 29 for providing fluid communication between the first adapter and the second adapter. In the present embodiment, the fluid connector 29 is a flexible hose. The flexible hose is curved away from the railway track 6.

Due to the P-shaped cross-sectional of the metal profile and to achieve that the flexible hose is curved away from the railway track 6, the first adapter 26 is a mirrored version of the second adapter 28.

In figs 10a, 10b and 10c different views of the second adapter 28 are shown with a metal profile interface 28a for connection to a left-side end of the metal profile 11 and with a hose interface 28b for connection to the flexible hose It supplies fluid to all ducts from one fluid connector 29 as shown in fig. 8.

The first adapter 26 will be similar to the second adapter 28, with one difference - the metal profile interface of the first adapter 26 will be configured to connect to a right-side end of the metal profile 11.

As shown in fig. 7a, the same first and second adapters are used to connect the metal profiles 10, 10b to the fluid line 9 of fig. 1.

The adapters are connected to the metal profile for example by means of fasteners such as screws. A sealing element, such as an O-ring may be provided between the adapters and the end surface of the metal profile to prevent fluid leakages.

Fig 8 shows a joint 30 where the first adapter 26 and the second adapter 28 provide a common fluid communication between the first duct 20 and the further duct 22 via one flexible connector 29. In the embodiment of fig. 2, the fluid from the first duct 20 and the further duct 22 of the heat transfer element 10 will be mixed in the flexible hose and then distributed into the first duct 20 and the further duct 22 of the further heat transfer element 10b. In the embodiment of fig. 3, the fluid from the first duct 20, the second duct 24 and the further duct 22 of the heat transfer element 10 will be mixed in the flexible hose and then distributed into the first duct 20, the second duct 24 and the further duct 22 of the further heat transfer element 10b.

In fig 1 la a further embodiment of the first and second adapter 26, 28 is shown.

Here the adaptors provide separate fluid communications between the ducts. The first adapter 26 and the second adapter 28 are fluidly connecting the first duct 20 of the heat transfer element 10 with the further duct 22 of the further heat transfer element 10b and the further duct 22 of the heat transfer element 10 with the first duct 20 of the further heat transfer element 10b.

In fig 1 lb another embodiment of the first and second adapter 26, 28 is shown. Here the adaptors also provide separate fluid communications between the ducts. The first adapter 26 and the second adapter 28 are fluidly connecting the first duct 20 of the heat transfer element 10 with the first duct 20 of the further heat transfer element 10b and the further duct 22 of the heat transfer element 10 with the further duct 22 of the further heat transfer element 10b.

Insulation of the heat transfer element

The heat transfer element 10 and the further heat transfer element 10b may also be provided with insulation to reduce thermal loss. As shown in fig. 3, the metal profile 11 comprises a further duct 22 provided on the opposite side 16 of the web facing side 15. The further duct 22 is alternatively an insulation duct. This insulation duct 22 may be filled with a gas, such as air, or it may be filled with a thermal insulation material 32 as shown in fig. 5. Fig. 9 shows the heat transfer element 10 provided with a thermal insulation barrier 33 (indicated by a solid line) on the outer surface 16 of the metal profile 11, opposite to the web-facing side 15.

Terminology

1 -heating and/or cooling system for heating and/or cooling of a railway track (6),

2 - heat or cooling source 4 - heat exchanger

5 - pump for circulating heated fluid

6 - railway track

7 - web of the railway track

8 - railway sleeper 9 - fluid line

10 - heat transfer element 10b - further heat transfer element 11 - metal profile

12 - ribs

15 - web-facing side of the metal profile

16 - outer surface

18 - top surface of the metal profile

20 - first duct 22 - further duct 24 - second duct

26 - first adapter

28 - second adapter

29 - fluid connector 30 - joint

32 - thermal insulation material

33 - thermal insulation barrier