DE102007026648B3 - Mechanical and thermal reinforcement for cable arrangement, has surface lying on mold in sealed manner, and comprising attenuation slot lying longitudinal to cable lines and another slot lying transverse to cable lines - Google Patents

Abstract

The reinforcement has a concrete e.g. fast setting concrete, mold (20) surrounding a cable arrangement (10). The surface of the cable arrangement lies on the mold in a sealed manner, and has an attenuation slot (22) that lies longitudinal to cable lines and an attenuation slot (24) that lies transverse to the cable lines. A joint mask (26) is inserted as a layer in the concrete mold, where the layer lies transverse to a cable longitudinal direction.

Description

The The invention relates to the mechanical and thermal reinforcement of a Cable assembly.

in the Framework of efforts electrical cable systems against the presence of magnetic fields (especially on the surface a cable trench), different proposals are known become. Some of these suggestions go from a tight bundling a cable assembly consisting of single conductor cables, which with Magnetfeldabschirmendem material are wrapped. The close bundling the single conductor cable is motivated by minimizing the magnetic field and the amount of magnetic field shielding material used as possible is kept small because the materials are expensive.

With the tight bundling The cable cores creates the problem of limited heat dissipation and thus of resilience.

A load reduction also occurs when the cable system is mechanically strengthened. It is known that cable defects on sleeve-free sections in the majority of cases caused by mechanical damage (dredging). Therefore, cable assemblies in the cable trench are placed in steel tubes or surrounded with mechanically stable fillers that can provide protection against mechanical damage. Combinations of magnetic field shielding with mechanical amplification are for example in the two applications WO 2004-034539 A1 . WO 2005-013450 A1 been proposed.

to Improvement of heat dissipation (according to the applicant's practice) so-called thermal stabilizers made of lean concrete (weak sand / gravel-cement mixture), the be opened in case of repair with relatively light interventions can, but therefore do not provide effective mechanical protection.

It is therefore the object of the invention, a mechanical and thermal reinforcement to propose cable systems, which avoids the disadvantages mentioned.

The solution the problem can be found in the characterizing part of the main claim, wherein in the subclaims further advantageous embodiments are formulated.

Of the The essence of the invention is that highly heat-conductive concrete is used in block form and that the concrete block at least one longitudinal and / or a transverse Weakening groove having. Cable systems for thermal and mechanical work with at least one dense, mechanically strong block of highly heat-conductive concrete to surround initially contradicts To use the today realized approach lean-concrete. Highly thermally conductive concretes have a high density due to the high solids content, or the small percentage of pores, so that one with a relatively small Volume of the reinforcement mass gets along. The cable system thermally stabilizing concrete block takes over thus additionally the function of mechanical protection.

Of course, the higher the thermal conductivity, the higher the load capacity increase made possible by the concrete block. High density concrete can be mixed with aggregates (such as graphite or the like) to achieve high thermal conductivity. Due to the small volume, the material offered by the company HeidelbergCement (dry mortar Thermocrete ^® ) with thermal conductivity of 2 ... 4 W / (K m) is very suitable despite its high specific cost.

Important is that the heat transfer is conveyed from the cable wires to the environment in the cable trench. Therefore, the concrete block should either be on the surface of the Cable arrangement rest well, or it should be between the individual cables the cable assembly and the reinforcing mass as concrete as possible no cavities remain.

Of the Concrete block is used for mechanical protection. Nevertheless, the accessibility the cable assembly with compacted concretes in case of repair too facilitate, in the concrete block weakening grooves along and / or formed transversely to the cable trench. Thus, a quick access to the cables, pipes or magnetic shielding possible if in case of an error, the cable trench must be opened.

The weakening, especially along the Line running weakening grooves are recessed at the top of the concrete block during concreting, whereby the Concrete block is mechanically weakened. Will now with heavy equipment hit the exposed concrete block, so is the elastic pipe assembly to give in something inside, resulting in a breakup the concrete block leads, without the cables lying in the pipes being exposed to the risk of damage become. Highly compacted concretes are relatively brittle, or can be mixed like this, that they are particularly brittle so that the destructive Effect of massive blows set quickly.

The concrete block should along the route have the transverse grooves at short intervals. The transverse grooves can both in the bottom of the concrete be formed as well as in his ceiling.

there can the lower transverse grooves easily by designing appropriate fittings (z. B. wedges made of wood, metal, etc.) before the concreting process become. Leave the upper transverse and longitudinal grooves easily penetrate and quickly set concrete Remove again appropriate moldings realize.

to Formation of the weakening zones In the upper part of the concrete block, combs or wedges can also be made of simple Material (plastic, wood) on the overhead cable core or the overhead duct can be put on. There is formed one Zone of lesser wall thickness of the concrete block, leaving the concrete block virtually weakened from the inside is.

Further embodiments have the following characteristics specified individually, each individually or may be claimed together.

In complement to transverse grooves or even instead of transverse grooves can in the concrete block joint masks transverse to the cable longitudinal direction be introduced. The joint masks should be layers of simple and cheap material. As a joint mask are therefore preferably thicker plastic films, plastic plates or wooden boards in question.

Preferably the concrete has fast setting property, thereby completing the finish the cable system is accelerated. The concrete block can thus with a constructed concreting device with sliding formwork be made continuously along the open cable trench. However, it is also much easier with the help of one beside the cable trench moving concreting car and a section by section advancing Hiking formwork.

repairs the, in particular piped cables can normally by replacing the cable length be made from the Muffenstellen ago. Only in special make the trench must be opened at the fault location and the described concrete block will be destroyed at this point. The mechanical protection achieved in this way has thus in particular for one Energy network operator Advantages.

It can out the amount of reinforcing mass Concrete can be saved if individual concrete blocks only piecewise and at a distance from each other be incorporated in the route. Such concrete blocks do not have to Have transverse grooves or joint masks, because of the necessary splittability in case of repair suffice the introduced longitudinal grooves. However, it is clear that the best mechanical and thermal amplification then is produced when the reinforcing mass gapless is introduced in the route.

Preferably If the cable assembly consists of the tight triangular composite Single-conductor cables or from in the tight triangular composite and bundled laid plastic conduits with retracted single-core cables. In the gussets the single-core cables, or the conduits can introduce additional conductor be. One more way the utilization of the gusset spaces in one of the aforementioned triangular associations exists in the storage other plastic conduits (smaller diameter), which together can be stranded with the single-core cables, or the conduits. The empty pipes (smaller diameter) can for retracting data transmission cables (eg fiber optic cable).

In the existing gussets the cable assembly may further incorporated a heat-storing mass be. For this there are materials that are used for latent heat storage. These work on the principle of phase transformation (phase changing material) and delay at the phase transformation, a further increase in temperature. In the Cable arrangement can thus avoid temperature peaks in overload situations.

From particular advantage is when the triangular composite of high-voltage single-conductor cable is covered with a magnetic shield.

magnetic Shielding has already been carried out by using high voltage cables were placed in a steel tube, on the one hand its magnetic Shielding effect and on the other hand take advantage of its magnetic protection. Since the concrete block offers a high mechanical protection, must magnetic shielding no solid material (like a steel pipe) be used. To shield enough relatively thin material.

by virtue of The present measurement results are particularly evident in a bundled in the Triangle arranged three-phase system an improvement of the magnetic Shielding. Therefore, offers itself particularly, the single cable of the Cable system bundled in three to collect arranged plastic conduits.

The magnetic shield can be constructed as follows: There is at least one inner container made of insulating material, for example a plastic tube with a circular or rectangular cross-section. The inner container can either accommodate a single cable or an inner container with a larger diameter becomes Unterbrin tion of the entire arranged in a triangle cable network used. On the inner container (s), there is an outer container made of insulating material, and the space between inner container (s) and outer container is filled with a ferromagnetic material layer of high magnetic permeability. The outer container is in turn a plastic tube with a circular or rectangular cross-section. Such an embodiment can be found for example in the DE 20 200 70 07 507 U1 ,

Of the Outer container can across from the at least one inner container be supported with spacer elements. The spacer elements can on the ferromagnetic material layer applied and clamped immovably be, wherein the spacer elements as tensioned on the inner container bands can be trained. To facilitate assembly (pulling into the outer container) point the spacer elements with respect to the Outer container one small coefficients of friction or are provided with means of reduction equipped with friction.

Of the Space between inner container and outer container can with a flowable, hardening Crowd filled be. This mass may preferably have a high thermal conductivity.

The ferromagnetic material layer may consist of at least one layer of ribbons made of soft magnetic material with a relative permeability of far more than 1,000, in particular at least 20,000, and preferably 45,000. For the bands become electrical tapes used, the known Have grain orientation.

The susceptible to corrosion electrical strips should be protected mechanically and be embedded corrosion-resistant. If an execution with the mentioned Used inside and outside containers is, should the container composite be formed moisture-tight.

Around the effort for the sealing of an inner / outer container composite To avoid, one can proceed as follows. The electrical tapes will open a carrying layer of plastic applied. The wearing layer can be made as a winding of plastic tapes around the cable assembly. The load-bearing layer is covered with water or water vapor Embedding layer wrapped. Then, the one-layer forming electrical tapes in the embedding layer is introduced and the magnetic shielding layer outwardly mechanically and corrosion protected longitudinally watertight with a cover layer sealed. These operations can with a suitable winding device continuously on the site be executed or already prepared in terms of color be.

embodiments The invention is illustrated in the drawings, which show:

1 Cross section through a concrete block with weakening grooves and

2 Structure of the magnetic shield in a triangular arrangement of the cables.

The 1 shows a cross section through a concrete block 20 , The cable arrangement 10 consists of three single conductor cables laid in the composite 12 , The cable assembly is covered with a magnetic shielding layer ( 32 . 34 . 36 ). The cable trench is with the concrete block 20 filled with different joints and grooves. Longitudinal grooves of the cable trench are located in the top of the concrete block 22 . 22 '; Of course, not a plurality of longitudinal grooves must be formed, but a single longitudinal weakening groove 22 can be sufficient. Transverse grooves extend transversely to the longitudinal extent of the cables 24 (side), below 24 ' and above 24 '' and joints. The joints are with a joint mask 26 filled. The mentioned in the description combs or wedges are not shown in the figures.

In 2 is a cable arrangement 10 ' shown without concrete block. In each with stranded plastic conduits 18 are single conductor cables 12 moved in. The gusset spaces between the plastic conduits 18 are by inserting additional conductors 14 filled. Instead of additional conductors and plastic conduits can be inserted with fiber optic cable. The triangular composite is enveloped by a magnetic shielding layer. At Innerst lies the magnetic material 34 wearing layer 32 ; Electrical tapes are part of the magnetic shielding layer 34 , Over it is a cover layer 36 , which seals the electrical tapes corrosion-resistant.

10

Cable assembly Triangular composite with magnetic shielding

10 '

Cable assembly Cables in conduits and additional conductors

12

Single Core

14

additional conductor

18

Plastic conduit

20

concrete block

22

longitudinal groove

22 '

parallel longitudinal groove above

24

transverse groove laterally

24 '

transverse groove above

24 ''

transverse groove below

26

joint mask

32

inner layer the magnetic shield

34

magnetic layer

36

outer layer the magnetic shield

Claims (14)

Mechanical and thermal reinforcement of a cable arrangement installed in a cable trench, consisting of an arrangement of electrical single-core cables, wherein concrete is used as material for reinforcing the cable system, characterized in that highly heat-conductive concrete in block form ( 20 ) that the concrete block ( 20 ) the cable arrangement ( 10 . 10 ' ) surrounds, rests tightly on the surface of the cable assembly and at least one longitudinal ( 22 . 22 ' ) and / or at least one weakening groove transverse to the cable race (US Pat. 24 . 24 ' . 24 '' ) having. Reinforcement of a cable arrangement according to claim 1, characterized in that the concrete ( 20 ) consists of fast-setting concrete. Reinforcement of a cable arrangement according to one of the preceding claims, characterized in that in the concrete block ( 20 ) at least one joint mask ( 26 ) is introduced as lying transversely to the cable longitudinal direction layer. Reinforcement of a cable arrangement according to the preceding claim, characterized in that the joint mask ( 26 ) consists of plastic. Reinforcement of a cable arrangement according to one of the preceding claims, characterized in that the cable arrangement ( 10 ) from single-conductor cables ( 12 ) or from a close triangular composite ( 10 ' ) of conduits ( 18 ) with retracted single-core cables ( 12 ) consists. Reinforcement of a cable assembly according to the preceding claim, characterized in that for the formation of weakening grooves combs or wedges are placed on the overhead cable core or the overhead empty tube, so that in the upper region of the concrete block ( 20 ) sets a reduction in material thickness during concreting. Reinforcement of a cable arrangement according to the preceding claim, characterized in that the cable arrangement ( 10 . 10 ' ) in the interstices of the single conductor cables, or in the interstices of the conduits additional conductor ( 14 ). Reinforcement of a cable arrangement according to one of the preceding claims, characterized in that in the interstices of the cable arrangement ( 10 . 10 ' ) is stored a heat-storing mass. Reinforcement of a cable arrangement according to one of the preceding claims, characterized in that the triangular connection of the single-core cables ( 12 ), or the conduits ( 18 ) with a magnetic shield ( 36 ) is wrapped. Reinforcement of a cable arrangement according to the preceding claim, characterized in that the magnetic shield is constructed as follows, - from at least one inner supporting layer ( 32 ) of insulating material, - of a magnetic shielding layer ( 34 ) covering layer ( 36 ) of insulating material, - the space between the inner supporting layer ( 32 ) and the covering layer ( 36 ) is filled with a ferromagnetic material layer ( 34 ) high magnetic permeability. Reinforcement according to claim 10, characterized in that the material layer ( 34 ) consists of at least one layer of strips of soft magnetic material having a relative permeability of much more than 1,000, in particular at least 20,000, and preferably 45,000. Reinforcement according to one of claims 10 or 11, characterized in that the inner supporting layer is used as inner container ( 32 ) and the covering layer as outer container ( 36 ) are formed, wherein the outer container ( 36 ) in relation to the inner container ( 32 ) with spacer elements ( 6 ) is supported. Reinforcement according to claim 12, characterized in that the space between inner containers ( 32 ) and outer container ( 36 ) is filled with a flowable, hardening mass. Reinforcement according to claim 13, characterized in that the space between inner containers ( 32 ) and outer container ( 36 ) is filled with a mass of high thermal conductivity.