DK2733266T3

DK2733266T3 - Transformer platform with cooling system

Info

Publication number: DK2733266T3
Application number: DK12192541.6T
Authority: DK
Inventors: Jörg Findeisen
Original assignee: Siemens Ag
Priority date: 2012-11-14
Filing date: 2012-11-14
Publication date: 2018-04-30
Also published as: NO2733266T3; EP2733266A1; EP2733266B1

Description

The invention relates to a transformer platform having at least one hollow structural element and having a cooling system for cooling at least one platform component of the transformer platform. A transformer platform is generally understood here to mean an offshore construction including its offshore platform and platform foundation. Particularly in the narrower sense, this includes transformer substations which are installed on an offshore platform, wherein the offshore platform and its platform foundation form component parts of the offshore transformer substation. In the broader sense, however, wind turbines for example with the associated foundations are also included in the transformer platforms in the sense of the application .

Transformer platforms usually comprise platform foundations, which are formed from steel tubes. Depending on the given conditions of use, various constructions are used, for example monopile foundations, which comprise only a single pile, jacket foundations, which comprise a steel framework construction, tripod foundations, which comprise a three-legged construction of steel tubes, which support a main pile under water, tripile foundations, which comprise three piles of steel tubing anchored at the seabed, onto which a three-legged construction is placed above water, or multi-pile systems. A cooling system for a transformer platform serves to cool the platform components, for example transformers, of the transformer platform. Amongst other things, radiators are used to cool transformers. Said radiators are subjected to a high level of corrosion exposure in the offshore sector. Especially for transformer platforms for high-voltage direct-current transmission, however, use is predominantly made of water cooling on account of the high total losses to be dissipated on account of the high total transmission to be carried away. Seawater is often used for cooling. The use of seawater for cooling also gives rise to a high level of corrosion exposure of the cooling system, especially of pumps for the seawater.

Furthermore, seawater used for the cooling causes contamination of the heat-exchanging surfaces of the heat exchangers, amongst other things due to algae, mussels and polyps (so-called fouling), and consequently a deterioration in the heat transfer coefficient. A preliminary filtration of the cooling water is therefore often used in cooling systems using seawater. The eguipment needed for this also requires maintenance. The protection of a cooling system based on seawater by means of high voltage is known from DE 10324228 A1. Spiral heat exchangers are known from DE 19913459 Cl, FR 2596144 A1 and DE 19810185 Cl. Improvements in the design of the tubular coolers are described in DE 19959467 B4. A deep-sea platform is known from WO 2006/069974 Al, wherein a heat exchanger unit of an electrical component is arranged undersea and cooling of the electrical component is thus enabled.

The problem underlying the invention is to provide a transformer platform that is improved with regard to the cooling of the platform components.

According to the invention, the problem is solved by the features of claim 1.

Advantageous developments of the invention are the subject-matter of the sub-claims. A transformer platform according to the invention comprises at least one hollow structural element and a cooling system for cooling at least one platform component of the transformer platform. The cooling system comprises a cooling circuit, in which a coolant is channelled, and at least one portion of the cooling circuit is formed by a hollow structural element of the transformer platform through which the coolant is channelled. A hollow structural element of a transformer platform is understood here to mean a tubular component of the offshore platform. In particular, a hollow structural element forms at least partially or even completely the load-bearing construction of the platform foundation of the offshore platform.

The cooling system thus makes use of hollow structural elements of the transformer platform, which are in any case present, as heat exchangers of the cooling circuit of the cooling system. The outer surfaces of the coolant-channelling hollow structural elements can be used to cool the coolant, in particular when these outer surfaces are arranged in the water (i.e. seawater) surrounding the transformer platform. The size of the cooling system and the platform costs are thus advantageously reduced.

An embodiment of the invention provides an intermediate cooling circuit, which is thermally arranged between the cooling circuit and at least one platform component of the transformer platform and is thermally coupled to the cooling circuit via a heat exchanger.

The use of an intermediate cooling circuit (as a primary cooling circuit) is particularly advantageous for cooling platform components, the cooling whereof requires a special and relatively expensive coolant, such as for example an insulating liquid for cooling transformers. As a result of the intermediate cooling circuit, the use of the expensive coolant can be advantageously limited to the intermediate cooling circuit, whilst a lower-cost coolant can be used in the circuit thermally coupled thereto and acting as a secondary cooling circuit, which in general is larger than the intermediate cooling circuit. A further embodiment of the invention provides for a plurality of interconnected hollow structural elements of the transformer platform, which together form a portion of the cooling circuit.

As a result of the connection of a plurality of hollow structural elements of the transformer platform to a portion of the cooling circuit, advantageously the volume and the outer surface of the cooler formed by the hollow structural elements of the transformer platform, which outer surface can be used for cooling the coolant, are advantageously increased. A further embodiment of the invention makes provision such that at least one hollow structural element, which forms a portion of the cooling circuit, is arranged at least partially in the water surrounding the transformer platform.

The water surrounding the transformer platform can thus advantageously be used to cool the coolant in the cooling circuit of the cooling system. A further embodiment of the invention provides for at least one thermoelectric generator, which is arranged on a hollow structural element, which forms a cooling circuit portion, below the water level of the water surrounding the transformer platform, in order to make use of a temperature difference between the temperatures of this water and of the coolant.

Hollow structural elements of the transformer platform are suitable particularly advantageously as cooling elements and/or coolant storage means, since they are usually arranged below the water level of the water surrounding the transformer platform and have large outer surfaces for cooling the coolant in the cooling circuit of the cooling system. A further embodiment of the invention makes provision such that at least one inner pipe is arranged in the interior of at least one hollow structural element which forms a portion of the cooling circuit, with the result that a region for channelling coolant is created between the hollow structural element and the inner pipe.

As a result of such an inner pipe, the required quantity of coolant in the cooling circuit of the cooling system can be advantageously reduced, since the interior of the inner pipe does not have to be filled with coolant, or the inner pipe can be advantageously used to separate portions of the cooling circuit from one another outside and inside the inner pipe, in which portions coolant flows in different directions. A development of this embodiment of the invention makes provision to connect the interior of at least one inner pipe to the surroundings of the hollow structural element containing the inner pipe, with the result that water surrounding the transformer platform can flow into the interior of the inner pipe and flow out of the interior of the inner pipe.

The interior of at least one inner pipe can thus be filled with seawater, so that not only seawater which surrounds the hollow structural element surrounding the inner pipe, but advantageously also seawater in the interior of the inner pipe can be used to cool the coolant in the cooling circuit of the cooling system.

Furthermore, an opening can be provided in at least one inner pipe towards the region between at least one inner pipe and the hollow structural element containing the inner pipe.

Coolant can thus be guided into the interior of the inner pipe, so that the interior and the exterior of the inner pipe can be used to channel coolant in opposite directions.

Further embodiments of the invention provide at least one first stiffening element which is arranged on a hollow structural element forming a cooling circuit portion and which is designed as a cooling rib for cooling coolant, and/or at least one second stiffening element which is arranged on an inner wall of a hollow structural element forming a cooling circuit portion and which has at least one coolant duct for channelling coolant.

Stiffening elements, which increase the stability of the transformer platform, can thus also advantageously be used to cool the coolant in the cooling circuit of the cooling system. A further embodiment of the invention provides for at least one flow-guiding device, which is arranged in a hollow structural element forming a cooling circuit portion, for the flow of the coolant in the hollow structural element.

Such flow-guiding devices can advantageously guide the flow of the coolant in the cooling circuit of the cooling system in such a way that the cooling of the coolant is optimised, in that the coolant is guided towards particularly effectively cooling regions of the cooling circuit.

Further embodiments of the invention make provision such that the coolant of the cooling circuit contains fresh water, Glysantin and/or corrosion inhibitor.

Fresh water has the advantage over salt water, which is often used as a coolant in conventional cooling systems of transformer platforms, that it is less corrosive. The use of fresh water therefore reduces the corrosion exposure of the cooling system and in particular its pumps and thus reduces the outlay on maintenance and servicing of the cooling system. Additives to the coolant such as Glysantin or corrosion inhibitor are advantageously suitable for reducing corrosion, reducing fouling and for frost protection of portions of the cooling circuit running above seawater level. A particularly preferred embodiment of the invention makes provision such that the cooling circuit is hermetically closed off with respect to the surroundings of the transformer platform.

The penetration of corrosive water and aggressive sea air from the surroundings of the transformer platform into the secondary circuit is thus prevented. This advantageously reduces the corrosion exposure of components of the secondary circuit, in particular the pumps, thus also reducing the maintenance outlay for these components and increasing their operational reliability . A further embodiment provides at least one gas-containing compensating space for taking up the thermally induced volumetric fluctuations of the coolant, so that the volumetric fluctuations of the coolant are taken up by compression of the gas. This compensating space is also advantageously arranged in a hollow structure of the platform foundation.

The size of the compensating space and the filling thereof with gas is preferably dimensioned such that the pressure difference with respect to the surroundings, which arises through the compression of the gas at a maximum expected temperature of the coolant, does not exceed 0.5 bar. Nitrogen is preferably provided as a filling gas of the compensating space for the volumetric fluctuations of the coolant.

The properties, features and advantages of this invention described above as well as the way in which the latter are achieved become clearer and more clearly understandable in connection with the following description of examples of embodiment, which are explained in greater detail in connection with the drawings. In the figures: FIG 1 shows diagrammatically a first example of embodiment of a transformer platform with a cooling system, FIG 2 shows diagrammatically a second example of embodiment of a transformer platform with a cooling system, FIG 3 shows diagrammatically a first embodiment of a hollow structural element of a transformer platform, said hollow structural element being constituted as a platform support leg, FIG 4 shows diagrammatically a second embodiment of a hollow structural element of a transformer platform, said hollow structural element being constituted as a platform support leg, FIG 5 shows diagrammatically a third embodiment of a hollow structural element of a transformer platform, said hollow structural element being constituted as a platform support leg, FIG 6 shows diagrammatically a third example of embodiment of a transformer platform with a cooling system, FIG 7 shows diagrammatically a fourth example of embodiment of a transformer platform with a cooling system, FIG 8 shows diagrammatically a first embodiment of a hollow structural element with coolant ducts in a cross- sectional representation, FIG 9 shows diagrammatically a second embodiment of a hollow structural element with coolant ducts in a cross- sectional representation, FIG 10 shows diagrammatically a third embodiment of a hollow structural element with coolant ducts in a cross- sectional representation, FIG 11 shows diagrammatically a fourth embodiment of a hollow structural element with coolant ducts in a cross- sectional representation, FIG 12 shows diagrammatically a fifth embodiment of a hollow structural element with coolant ducts in a cross- sectional representation, FIG 13 shows diagrammatically a sixth embodiment of a hollow structural element with coolant ducts in a cross- sectional representation, FIG 14 shows diagrammatically a seventh embodiment of a hollow structural element with coolant ducts in a longitudinal sectional representation, FIG 15 shows diagrammatically two coolant-channelling hollow structural elements, which are connected by means of a grout connection, FIG 16 shows a first embodiment of a hollow structural element forming a node element for the connection of coolantchannelling hollow structural elements, FIG 17 shows a second embodiment of a hollow structural element forming a node element for the connection of coolant-channelling hollow structural elements, FIG 18 shows a third embodiment of a hollow structural element forming a node element for the connection of coolantchannelling hollow structural elements, FIG 19 shows a fourth embodiment of a hollow structural element forming a node element for the connection of coolant-channelling hollow structural elements, FIG 20 shows a fifth embodiment of a hollow structural element forming a node element for the connection of coolantchannelling hollow structural elements, and FIG 21 shows a sixth embodiment of a hollow structural element forming a node element for the connection of coolantchannelling hollow structural elements.

Parts corresponding to one another are provided with the same reference numbers in all the figures.

Figure 1 shows diagrammatically a first example of embodiment of a transformer platform 1 with a cooling system 3 for cooling a platform component 11. Platform component 11 is for example a transformer .

Transformer platform 1 is located in water 7 in the open sea off a coast. The platform foundation of transformer platform 1 comprises a plurality of vertically running hollow structural elements 2 forming support legs, which are constituted as steel tubes and form foundation legs of transformer platform 1, which projected out of water 7 and support a platform head 10 of transformer platform 1, on which platform component 11 is located. These foundation legs are connected to one another by connecting hollow structural elements 23, 24 running below water level 71 of water 7 surrounding transformer platform 1, wherein a first connecting hollow structural element 24 runs obliquely to the foundation legs and second connecting hollow structural element 23 runs orthogonal to the foundation legs below first connecting hollow structural element 24.

Cooling system 3 comprises an intermediate circuit 3.1 constituted as a primary cooling circuit and a cooling circuit 3.2 constituted as a secondary cooling circuit, which are thermally coupled via a heat exchanger 31.

Intermediate circuit 3.1 is thermally coupled directly to platform component 11. It comprises first conduits 35 and a first pump 33.

Cooling circuit 3.2 comprises a second conduits 36, a second pump 34 as well as hollow structural elements 2 forming support legs and connecting hollow structural elements 23, 24. A coolant 39 is pumped through cooling circuit 3.2 by means of second pump 34.

Fresh water is preferably used as coolant 39 in cooling circuit 3.2. For the reduction of corrosion, reduction of fouling and for frost protection of portions of cooling circuit 3.2 running above water level 71 of water 7 surrounding transformer platform 1, additives, for example Glysantin and/or corrosion inhibitor, can also be added to the fresh water.

Hollow structural elements 2 forming support legs and connecting hollow structural elements 23, 24 thus channel coolant 39 and are integrated into cooling circuit 3.2. Since they have large outer surfaces lying below water level 71 of water 7 surrounding the transformer platform, coolant 39 in hollow structural elements 2 forming support legs and in connecting hollow structural elements 23, 24 can thus be efficiently cooled.

Hollow structural elements 2 forming support legs are filled with coolant 39 in such a way that a coolant level 73 of coolant 39 in these regions 21 lies above water level 71 of water 7 surrounding transformer platform 1. In the case of small leakages of hollow structural elements 2, 23, 24, corrosive water 7 surrounding them is thus advantageously prevented from penetrating into hollow structural elements 2, 23, 24 and therefore into cooling circuit 3.2.

An inner pipe 22 is arranged in a first of hollow structural element 2 forming support legs, with the result that a region 21 for channelling coolant 39 is created around inner pipe 22 between this hollow structural element 2 and inner pipe 22. Inner pipe 22 is connected to second connecting hollow structural element 23 and comprises an opening 28 to the latter, through which coolant 39 can flow from second connecting hollow structural element 23 into inner pipe 22.

Coolant 39 is pumped through cooling circuit 3.2 by means of second pump 34, so that it flows as indicated by the arrows in fig. 1: coolant 39 flows from heat exchanger 31 via a second conduit 36 into region 21 surrounding inner pipe 22 in the first of hollow structural elements 2 forming support legs; from there, coolant 39 flows along inner pipe 22 downwards and into first connecting hollow structural element 24; it flows via first connecting structural element 24 into the second of hollow structural elements 2 forming support legs and from there into second connecting hollow structural element 23; coolant 39 then flows from second connecting hollow structural element 23 through opening 28 into inner pipe 22 and from there finally back to heat exchanger 31 via a second conduit 36 projecting into inner pipe 22.

First stiffening elements 41 are arranged in each case at the outer sides of hollow structural element 2 forming support legs, which stiffening elements are designed as cooling ribs, which enlarge the outer surfaces of these hollow structural elements 2, for cooling of coolant 39.

Figure 2 shows diagrammatically the second example of embodiment of a transformer platform 1 with a cooling system 3 for cooling a platform component 11. In this example of embodiment, platform component 11 is also for example a transformer.

As in the first example of embodiment, transformer platform 1 is located in water 7 in the open sea off a coast and the platform foundation of transformer platform 1 comprises a plurality of hollow structural elements 2 forming support legs, which are constituted as steel tubes and form foundation legs of transformer platform 1. These foundation legs are connected to one another by connecting hollow structural elements 23, 24 running below water level 71 of water 7 surrounding transformer platform 1, wherein a first connecting hollow structural element 24 runs obliquely to the foundation legs and second connecting hollow structural element 23 runs orthogonal to the foundation legs below first connecting hollow structural element 24.

As in the first example of embodiment, cooling system 3 also comprises an intermediate circuit 3.1 constituted as a primary cooling circuit and a cooling circuit 3.2 constituted as a secondary cooling circuit, which are thermally coupled via a heat exchanger 31, wherein intermediate circuit 3.1 is thermally coupled directly to platform component 11 and is constituted analogous to the first example of embodiment.

Cooling circuit 3.2 comprises a second conduit 36, a second pump 34 as well as hollow structural elements 2 forming support legs and first connecting hollow structural element 24. A coolant 39 is pumped through cooling circuit 3.2 by means of second pump 34.

In the second example of embodiment, an inner pipe 22 is arranged in each of hollow structural element 2 forming support legs, with the result that a region 21 for channelling coolant 39 is created around inner pipe 22 between this hollow structural element 2 and inner pipe 22. The two regions 21 of hollow structural elements 2 forming support legs are connected to one another by first connecting hollow structural element 24.

In contrast with the first example of embodiment, however, no coolant 39 of cooling circuit 3.2, but rather water 7 of the sea surrounding transformer platform 1 is channelled in inner pipe 22 of a first of hollow structural element 2 forming support legs. For this purpose, the interior of this inner pipe 22 is connected by connecting ducts 47, 48 to the surroundings of hollow structural element 2 containing inner pipe 22, so that water 7 surrounding transformer platform 1 can flow through first connecting ducts 47 into the interior of inner pipe 22 and through second connecting ducts 48 out of the interior of inner pipe 22. Second connecting ducts 48 are arranged above first connecting ducts 47, so that water 7, which has entered through the first connecting ducts 47 into inner pipe 2 and is heated by the absorption of heat from coolant 39, rises inside inner pipe 22 and can exit out of inner pipe 22 through second connecting ducts 48. A pump is not therefore required to pump water 7 through inner pipe 22. Inner pipe 22 of the first of hollow structural element 2 forming support legs advantageously increases the surface of this hollow structural element 2 through which water 7 of the sea flows and thus improves the cooling of coolant 39 in this hollow structural element 2.

Inner pipe 22 in the second of hollow structural elements 2 forming support legs is constituted like inner pipe 22 in the first of hollow structural elements 2 forming support legs of the first example of embodiment, i.e. it comprises at least one opening 28 to coolant-filled region 21 between it and the second of hollow structural elements 2 forming support legs, so that coolant 39 can flow out of this region into this inner pipe 22.

Regions 21 surrounding inner pipes 22 in the interior of hollow structural elements 2 forming support legs and inner pipe 22 of the second of hollow structural element 2 forming support legs are filled with coolant 39 in the same way as the first example of embodiment, in such a way that coolant level 73 of coolant 39 lies above water level 71 of water 7 surrounding transformer platform 1.

Coolant 39 is pumped through circuit 3.2 by means of second pump 34, so that the coolant flow indicated by way of example by the arrows in figure 2 is established: coolant 39 flows from heat exchanger 31 via a second conduit 36 into region 21 in the first of hollow structural elements 2 forming support legs, which region surrounds inner pipe 22 arranged there; from there, coolant 39 flows along inner pipe 22 downwards and into first connecting hollow structural element 24; it flows via first connecting structural element 24 into region 21 in the second of hollow structural elements 2 forming support legs, which hollow structural element surrounds inner pipe 22 arranged there, and from there flows through the at least one opening 28 into this inner pipe 22; coolant 39 finally flows out of this inner pipe 22 back to heat exchanger 31 via a second conduit 36 projecting into this inner pipe 22.

Figures 3 to 5 show embodiments of coolant-channelling hollow structural elements 2 forming support legs with various stiffening elements 41, 42, 43, which both improve the stability of these hollow structural elements 2 and also serve to cool coolant 39 in these hollow structural elements 2. Stiffening elements 41, 42, 43 are also preferably constituted such that they serve as flow-guiding devices.

Figure 3 shows a hollow structural element 2 forming a support leg, at the outer wall whereof outer first stiffening elements 41 designed as cooling ribs are arranged, and at the inner wall whereof coolant-channelling second stiffening elements 43 are arranged, which each comprise at least one (coolant duct, not represented in detail) for channelling coolant 39 and run vertically.

Figure 4 shows a hollow structural element 2 forming a support leg, at the outer wall whereof four vertically running coolantchannelling second stiffening elements 43 are arranged, and at the inner wall whereof first stiffening elements 42 designed as cooling ribs are arranged. Middle second stiffening element 43 represented in figure 4 is thus also located at the outer wall of hollow structural element 2 forming a support leg and is represented here in order to indicate that the four second stiffening elements 43 are arranged offset by 90 degrees from one another along the circumference of a cross-section of the outer wall of this hollow structural element 2.

Figure 5 shows a hollow structural element 2 forming a support leg, at the inner wall whereof horizontally running coolantchannelling second stiffening elements 43 are arranged above one another.

Figure 6 shows diagrammatically a third example of embodiment of a transformer platform 1 with a cooling system 3 for cooling a platform component 11. In this example of embodiment, platform component 11 is also, by way of example, a transformer .

The platform foundation of this example of embodiment is constituted in the manner of a framework comprising elongated hollow structural elements 27.1 forming a framework structure and hollow structural elements 27.2 forming node elements in each case connecting a plurality of these hollow structural elements 27.1. Hollow structural elements 27.2 forming node elements can be constituted for example as cylindrical, spherical or multi-faced bodies and are usually welded to hollow structural elements 27.1 forming the framework structure, which hollow structural elements connect them in each case. Hollow structural elements 27.2 forming node elements are advantageously constituted as cast nodes.

Cooling system 3 is constituted similar to the examples of embodiment represented figures 1 and 2 and comprises an intermediate cooling circuit 3.1 and a cooling circuit 3.2 thermally coupled thereto via a heat exchanger 31. Cooling circuit 3.2 comprises hollow structural elements 27.1, 27.2 of the platform foundation, which hollow structural elements run below water level 71 of water 7 surrounding transformer platform 1 and through which a coolant 39 of cooling circuit 3.2 is pumped by means of a second pump 34. Coolant 39 is conveyed by means of a second conduit 36 of cooling circuit 3.2 into the platform foundation and out of the latter.

The interior spaces of hollow structural elements 27.1, 27.2 included in cooling circuit 3.2 are connected to one another in such a way that a circulation of coolant 39 is conveyed inside the platform foundation. A self-propulsion of the coolant flow occurs as a result of the increase in the density of coolant 39 arising during the cooling at the walls of hollow structural elements 27.1, 27.2. Obliquely or horizontally running hollow structural elements 27.1 forming the framework structure are advantageously connected to at least approximately vertically running hollow structural elements 27.1 forming the framework structure, in such a way that this self-propulsion of the coolant flow, the direction whereof is indicated by way of example by arrows in figure 6, is assisted and runs in the pumping direction of second pump 34. For this purpose, flow-guiding devices are provided in hollow structural elements 27.2 forming node elements, which flow-guiding devices enable a directed coolant flow between hollow structural elements 27.1 forming the framework structure. Various possible embodiments of hollow structural elements 27.2 thus constituted are represented in figures 16 to 21 described below.

The return of coolant 39 from the platform foundation preferably takes place such that the removal takes place in the lowest part of the platform foundation. In the example of embodiment represented in figure 6, coolant 39 is fed back to heat exchanger 31 via a second conduit 36, which is arranged inside a vertically running hollow structural element 27.1.

In this example of embodiment, the cooling effect of the platform foundation can also be increased by inner or outer first stiffening elements 41, 42 (not represented in figure 6) designed as cooling ribs on hollow structural elements 27.1 forming the framework structure, which stiffening elements are constituted such that they contribute to the mechanical strength of the platform foundation.

In further developments of the example of embodiment represented in figure 6, further flow-guiding devices or vortex generators are arranged inside hollow structural elements 27.1, 27.2 in order to achieve a turbulent flow.

Figure 7 shows diagrammatically a fourth example of embodiment of a transformer platform 1 with a cooling system 3 for cooling a platform component 11. Platform component 11 is also, for example, a transformer in this example of embodiment.

The tripod foundation comprises three hollow structural elements 2 forming support legs constituted as foundation legs, by means of which transformer platform 1 is erected on a seabed 8, a hollow structural element 25 forming a load-bearing structure, the upper end whereof projects out of water 7 surrounding transformer platform 1 and supports platform head 10 of transformer platform 1, as well as two connecting hollow structural elements 23, 24 for each of hollow structural element 2 forming support legs, which connecting hollow structural elements connect respective hollow structural element 2 to hollow structural element 25 forming the load-bearing structure. In each case, a first connecting hollow structural element 24 runs from hollow structural element 25 forming the load-bearing structure obliquely downwards to hollow structural element 2 forming a support leg and second connecting hollow structural element 23 runs below first connecting hollow structural element 24 almost parallel to seabed 8. Connecting hollow structural elements 23, 24 each comprise openings 28 to hollow structural element 25 forming the support structure and respective hollow structural element 2 forming a support leg, so that the interior spaces of all hollow structural elements 2, 23, 24, 25 form an interconnected hollow space, which is closed off hermetically with respect to the surroundings of transformer platform 1.

Cooling system 3 comprises an intermediate cooling circuit 3.1 and a cooling circuit 3.2, which is thermally coupled thereto via a heat exchanger 31 and which, in this example of embodiment alone, is formed by hollow structural elements 2, 23, 24, 25. In addition, the hollow space formed by the interior spaces of hollow structural elements 2, 23, 24, 25 is filled with coolant 39 of cooling circuit 3.2 and heat exchanger 31 is arranged in coolant 39 inside the interior spaces of hollow structural element 25 forming the support structure .

The direction of the coolant flow in cooling circuit 3.2 is indicated by arrows in figure 7. Coolant 39 is heated by means of heat exchanger 31 and rises inside hollow structural element 25 forming the load-bearing structure. Coolant 39 is cooled at the walls of hollow structural elements 2, 23, 24, 25 and falls, on account of its density increasing due to the cooling, through connecting hollow structural elements 24 into the interior spaces of hollow structural elements 2 forming support legs and from there flows through the interior spaces of second connecting hollow structural elements 23 back into the interior space of hollow structural element 25 forming the load-bearing structure to heat exchanger 31. A natural coolant flow is thus created inside the platform foundation, which coolant flow can be intensified if need be by a second pump 34 (not represented in figure 7).

In order to increase the flow rate and the effectiveness of cooling system 3, parts of hollow structural elements 2, 23, 24, 25 can be constituted multi-walled and can for example be provided with an inner pipe 22. To increase the cooling surface, hollow structural elements 2, 23, 24, 25 can be provided with inner or outer first stiffening elements 41, 42 designed as cooling ribs.

Similar to the examples of embodiment represented in figures 1 and 2, the platform foundation of transformer platform 1 is filled with coolant 39 in such a way that a coolant level 73 of coolant 39 lies above water level 71 of water 7 surrounding transformer platform 1. Furthermore, the filling is selected such that a coolant-free compensating space 29 remains above coolant level 73, in order to compensate for temperature-related volumetric changes in coolant 39 in coolant circuit 3.2. Compensating space 29 is preferably filled with a gas, for example with nitrogen, such that the differential pressure with respect to the surroundings which arises at a maximum expected temperature of coolant 39 remains less than 0.5 bar in compensating space 29. Cooling circuit 3.2 including the hollow structural elements included in the cooling circuit is thus advantageously hermetically closed off with respect to the surroundings of transformer platform 1.

Figures 8 to 13 each show diagrammatically in a cross-sectional representation an embodiment of a hollow structural element 2 forming a support leg with tubular coolant ducts 51 channelling coolant 39. Such embodiments are suitable not only for hollow structural elements 2 forming support legs, but also for other hollow structural elements 23, 24, 25, 27.1, 27.2 shown in figures 1, 2, 6, 7.

Figures 8, 12 and 13 each show coolant ducts 51 arranged on the outside on hollow structural element 2 forming a support leg, wherein coolant ducts 51 of the embodiment represented in figure 8 have U-shaped cross-sectional contours, whereas the embodiments represented in figures 12 and 13 have circular cross-sectional contours.

Figures 9 to 11 each show coolant ducts 51 arranged on the inside on a hollow structural element 2 forming a support leg, wherein coolant ducts 51 of the embodiment represented in figure 9 have U-shaped cross-sectional contours, whereas the embodiments represented in figures 10 and 11 have circular cross-sectional contours.

Coolant ducts 51 of the embodiments represented in figures 8 to 10 and 13 are arranged directly on hollow structural element 2 forming a support leg, whereas coolant ducts 51 of the embodiments represented in figures 11 and 12 are connected by webs 52 to hollow structural element 2 forming a support leg.

Figure 14 shows, in a longitudinal representation in the form of a detail, a hollow structural element 2 forming a support leg, on which there are arranged on the inside coolant ducts 51 with coolant inlet ducts 54.1 for supplying coolant 39 and coolant outlet ducts 54.2 for discharging coolant 39. This hollow structural element 2 also comprises water inlet openings 53.1 below coolant ducts 51 and water outlet openings 53.2 above coolant ducts 51, through which water 7 surrounding transformer platform 1 can flow into the interior of this hollow structural element 2 and out of the interior of this hollow structural element 2. The arrows indicate the directions in which coolant 39 or water 7 flows in each case.

Figure 15 shows diagrammatically two hollow structural elements 2.1, 2.2, which are connected by means of a so-called grout connection 9. Hollow structural elements 2.1, 2.2 are mounted, wherein one end of a first hollow structural element 2.1 is introduced into second hollow structural element 2.2, and an intermediate space between hollow structural elements 2.1, 2.2 is filled with a grouting material 91, for example a high-strength concrete or mortar. Tolerances and inclined positions of hollow structural elements 2.1, 2.2 can thus be compensated for and a force flux can be produced between them. Grouting material 91 is introduced via a material inlet connection 92 in second hollow structural element 2.2. Furthermore, second hollow structural element 2.2 comprises an outlet opening 93 for the venting and/or evacuation of a medium displaced when grouting material 91 is introduced.

An embodiment of the invention makes provision such that coolant-channelling hollow structural elements 2.1, 2.2, which are connected by means of such a grout connection 9, are connected to one another by at least one coolant-connecting element 94 through which coolant 39 can be guided. For this purpose, one of hollow structural elements 2.1, 2.2 is provided with coolant-connecting element 94, whilst a receiving device 95, for example a corresponding opening, is provided in the other hollow structural element 2.1, 2.2 for receiving coolantconnecting element 94, so that the interior of coolant connecting element 94 remains free from grouting material 91 during the filling process of grouting material 91.

Figures 16 to 21 each show diagrammatically in a cross-sectional representation a hollow structural element 27.2 of a transformer platform 1 constituted as in figure 6, said hollow structural element forming a node element. Hollow structural elements 27.2 forming node elements each comprise a flow-guiding device for guiding coolant 39 flowing through them.

Hollow structural elements 27.2 forming node elements shown in figure 16 to 21 each differ from one another in their shape and/or the embodiment of the flow-guiding device.

Figure 16, 19 and 20 each show hollow structural elements 27.2 forming node elements, the flow-guiding device whereof is constituted as an inner wall 83, by means of which coolant 39 is guided by one of hollow structural elements 27.1 forming a framework structure into another of these hollow structural elements 27.1.

Figure 17, 18 and 21 each show hollow structural elements 27.2 forming node elements, the flow-guiding device whereof comprises at least one pipe segment 85, through which coolant 39 is channelled. The flow-guiding devices of hollow structural elements 27.2 forming node elements represented in figures 18 and 21 also comprises lateral duct closures 84, which close the outlets of these hollow structural elements 27.2 forming node elements around pipe segments 85, said outlets being used for pipe segments 85, so that coolant 39 can pass through these outlets only inside pipe segments 85. An intersection of coolant flows running in different directions inside these hollow structural elements 27.2 is thus advantageously enabled, as is indicated by arrows in figure 21. Lateral duct closures 84 can be constituted for example as caps.

In all the examples of the embodiment represented in figures 1, 2, 6 and 7, use is made of no pumps, filters or coolers through which water 7 surrounding transformer platform 1 flows. The servicing and maintenance outlay for the components of cooling circuit 3.2 compared to cooling systems 3 using such water 7 is thus advantageously reduced considerably. Moreover, the operational reliability of these components is improved, so that a redundant provision of these components to safeguard the operation can also advantageously be reduced.

The represented examples of embodiment can be combined and/or developed in different ways. A possible development provides for example for profiles, for example U-profiles, on at least one inner wall of a hollow structural element 2, 23, 24, 25, 27.1, 27.2, which profiles are provided in a such way that they form spaces that can be used for the coolant transport. In order to keep the required pump output low in cooling circuit 3.2, the connection of hollow structural elements 2, 23, 24, 25, 27.1, 27.2 to coolant ducts also preferably takes place in such a way that the natural self-proportion of coolant 39 driven by the force of gravity (i.e. by a density difference) is assisted. Depending on the structure of transformer platform 1, the use of existing geometries for heat dissipation is advantageous. If, for example, vertical or horizontal pipes (e.g. a support leg or a transverse strut) can be used as cooling surfaces, a lower surface effectiveness of these cooling surfaces can be accepted. Hollow structural elements 2, 23, 24, 25, 27.1, 27.2 of the platform foundation of transformer platform 1 that are used for cooling are advantageously constituted such that they form a large catchment area for the natural water flow of water 7. Furthermore, additional water flow is channelled by means of suitable flow-guiding devices to the structural parts of the platform foundation that serve as coolers. In a special embodiment, additional heat-dissipating surfaces are provided at the outer side of hollow structural elements 2, 23, 24, 25, 27.1, 27.2, which additional surfaces are expediently located in regions with favourable coolant flow conditions. Depending on the flow conditions, these surfaces can be provided both horizontally and vertically or at an angle. The shape and arrangement of these surfaces is selected such that, on the one hand, a maximum coverage with the cooling medium, water 7, takes place, but at the same time a disruption of the coverage of other heat-dissipating parts is avoided. In a special embodiment, the additional cooling surfaces can be constituted such that they serve as a flow-guiding device.

In a further embodiment, at least one thermoelectric generator is arranged on a hollow structural element 2, 23, 24, 25, 27.1, 27.2, which forms a cooling circuit portion, below water level 71 of water 2 surrounding transformer platform 1, in order to utilise a temperature difference between temperatures of this water 7 and coolant 39.

Although the invention has been illustrated and described more closely in detail by preferred examples of embodiment, the invention is not limited by the disclosed examples and other variations can be derived therefrom by the person skilled in the art without departing from the scope of protection of the invention .

Claims

A transformer platform (1) having at least one hole structure element (2, 23, 24, 25, 27.1, 27.2, 2.1, 2.2) and with a cooling system (3) for cooling at least one platform component (11) of the transformer platform (1), wherein - the cooling system (3) comprises a cooling circuit (3.2) in which a refrigerant (39) is provided, - and at least a portion of the cooling circuit (3.2) is constituted by a hollow structure element (2, 23, 24, 25, 27.1, 27.2, 2.1 , 2.2) through which the refrigerant (39) is passed, characterized in that the hollow structure element (2, 23, 24, 25, 26, 27.1, 27.2, 2.1, 2.2) is a tubular shaped component which forms at least partly the supporting structure. of the transformer platform (1) platform foundation.

Transformer platform (1) according to claim 1, characterized by an intermediate cooling circuit (3.1) which is thermally disposed between the cooling circuit (3.2) and at least one platform component (11) of the transformer platform (1) and is thermally connected to the cooling circuit (3.2) via a heat exchanger (31).

Transformer platform (1) according to one of the preceding claims, characterized by a plurality of hollow structural elements (2, 23, 24, 25, 27.1, 27.2, 2.1,2.2) which are connected to each other and which together constitute a section of the cooling circuit ( 3.2).

Transformer platform (1) according to one of the preceding claims, characterized in that at least one hollow structure element (2, 23, 24, 25, 27.1, 27.2, 2.1, 2.2) which forms part of the cooling circuit (3.2) in it at least partially disposed in the water (7) surrounding the transformer platform (1).

Transformer platform (1) according to claim 4, characterized by at least one thermoelectric generator arranged on a hollow structure element (2, 23, 24, 25, 27.1, 27.2, 2.1, 2.2), which forms a cooling circuit section, below the water level of the water. (7), which surrounds the transformer platform (1), to utilize a temperature difference between temperatures of this water (7) and the refrigerant (39).

Transformer platform (1) according to one of the preceding claims, characterized in that in the interior of at least one hollow structure element (2, 23, 24, 25, 27.1, 27.2, 2.1, 2.2) which forms a section of the cooling circuit ( 3.2), at least one inner tube (22) is arranged so that an area (21) for guiding between the hollow structure element (2, 23, 24, 25, 27.1,27.2, 2.1,2.2) and the inner tube (22) of refrigerant (39).

Transformer platform (1) according to claim 6, characterized by connecting channels (47, 48) connecting the interior of at least one inner tube (22) with the surroundings of the hollow structure element (2, 23, 24, 25, 27.1, 27.2, 2.1). 2.2) containing the inner tube (22) so that water (7) surrounding the transformer platform (1) can flow into the interior of the inner tube (22) and out of the interior of the inner tube (22) ).

Transformer platform (1) according to claim 6 or 7, characterized by at least one opening (28) in at least one inner tube (22) for the area (21) between the inner tube (22) and the hollow structure element (2, 23, 24, 25 , 27.1, 27.2, 2.1, 2.2), which contains the inner tube (22).

Transformer platform (1) according to one of the preceding claims, characterized by at least one stiffening element (41, 42, 43), said stiffening element being arranged on a hollow structure element (2, 23, 24, 25, 27.1, 27.2, 2.1,2.2). which constitutes a cooling circuit section and which bracing element is configured as a cooling rib for cooling refrigerant (39) or having at least one refrigerant channel (51) for guiding refrigerant (39).

Transformer platform (1) according to one of the preceding claims, characterized by at least two refrigerant conducting hollow structure elements (2.1, 2.2) connected by a grout connection (9), where their refrigerant conducting areas are connected to each other via at least one refrigerant connection element (94) through which refrigerant (39) can be conducted.

Transformer platform (1) according to one of the preceding claims, characterized by at least one flow conductor device arranged in a hollow structure element (2, 23, 24, 25, 27.1, 27.2, 2.1, 2.2), which constitutes a cooling circuit section, for the refrigerant (39) flow in the hollow structure element (2, 23, 24, 25, 27.1,27.2, 2.1,2.2).

Transformer platform (1) according to one of the preceding claims, characterized by at least one hollow structure element (27.2), which constitutes a knot element, which connects other refrigerant conducting hollow structure elements (27.1) and has in its interior a flow conductor device for controlling the refrigerant (39). .

Transformer platform (1) according to one of the preceding claims, characterized in that the cooling circuit (3.2) including at least one hollow structure element (2, 23, 24, 25, 27.1) constituting a cooling circuit section is hermetically sealed with respect to the transformer platform ( 1) surroundings.

Transformer platform (1) according to one of the preceding claims, characterized by at least one compensating space (29) containing a gas for accommodating refrigerant (39) in the cooling circuit (3.2) by volume changes of the refrigerant (39).