DE102012021415B3 - Method for preparation of pipes for measurement of environment-relevant parameters, involves attaching terminals of optical fiber cable in top-side tube portion on tube wall for transferring transmitted and received light signals - Google Patents

Abstract

The method involves recording optical fiber cable (3) to the values is measured. The terminals (16,17) of the light guide cable to a light-emitting unit (18) configured for emitting light signals. A detector unit (19) is provided for detecting the received light signals. A recess (7) is created in the tube wall (4).The optical fiber cable is inserted into the recess. The terminals of optical fiber cable are attached in the top-side tube portion (28) on the tube wall for transferring the transmitted light signals and to transfer the received light signals. An independent claim is included for a pipe.

Description

The invention relates to a method for producing tubes with optical fiber cable for measuring environmental variables, wherein the tube has at least one tube wall, which is formed at least with at least one associated with the tube optical fiber cable, wherein the dimensions to be measured in the optical fiber cable at least in one Section of the optical fiber cable are detected, wherein at least one connection of the optical fiber cable to a light emitting unit for emitting light signals and to a detection unit for detecting the received light signals is present.

Application of the invention

The invention is applicable to the fields in which optical fiber cables are used in combination with pipes. This happens z. For leak monitoring of pipelines and geothermal probes. For geothermal probes, the application of great interest, since there is no accessibility of the field of application. The operation of geothermal probes can be adjusted by means of temperature monitoring. Composite probes / tubes are predestined for the measuring method, since at least one metallic layer is inserted here. For example, as in 1 under the Internet address: https://deranitaermarkt.de/media/satchmo_images/productimage-picture-5-schicht-verbundrohr-unipipe-16-x-2mm-weiss-in-ring-je-200m-3579.jpg is shown, is such a composite pipe 1 shown for a probe that from the inside out of a first PE-RT wall 30 , a layer 31 Adhesive, a metallic wall 32 made of aluminum, a further second layer located thereon 31 Adhesive and finally on the outside of a second PE-RT wall 30 exists and is equipped without fiber optic cable.

These probes have advantages over pure PE probes, which are conventionally standard in geothermal energy. It can be assumed that the probes in combination with the fiber-optic cable can be used to measure environmental variables especially in locations where monitoring of geothermal probes is desired. This is the case for fields of geothermal probes as well as for geothermal heat storage.

State of the art

The process for fiber optic temperature measurements has been known since the early 1980's. The method is based on the OTDR (Optical Time Domain Reflectrometry) method. The resulting DTS (Distributed Temperature Sending) method enables temperature measurements along the entire fiber optic cable with high accuracy and at short distances.

The DTS method for the monitoring of temperature distributions and / or temperature anomalies is in the document DE 199 21 256 A1 described. The detection of temperature-side local extremes, ie minima or maxima, is performed by an evaluation without numerical derivatives. With the device for monitoring of surrounding with an annulus risers or delivery pipes, it is possible to check particularly cost the safety of pressurized equipment, especially in the field of vacuum gas storage. Furthermore, on the basis of fiber-optic temperature measurements, the position of an underground watershed or the direction and magnitude of the flow in flooded tunnel sections can be determined. Likewise, it is possible by a defined arrangement of preferably vertical, sunken in holes sensor cables to investigate the tightness of the sole and side boundaries of excavations. Ultimately, the near-horizontal arrangement of meandering laid multi-level fiber optic cables can evaluate and control the effectiveness and homogeneity of leaching processes in leaching dumps or landfills.

The finding of leaks in gas-carrying pipes is in the document DE 298 11 737 U1 described. The associated device for monitoring the leakage of pipelines, in particular of surrounding with an annulus risers or conveyor pipes for underground gas storage by means of fiber optic sensor cable is used to determine the temperature distribution or temperature anomalies. The fiber-optic sensor cable is arranged inside the riser pipe or the delivery pipe and leads to the outside via a pressure-tight seal. Furthermore, the outer end of the fiber optic sensor cable is connected to a measuring unit for injecting radiation pulses and receiving backscatter radiation.

The listed applications are only a part of. Nevertheless, the enormous benefits of such an installation are pointed out.

Currently, corresponding fiber optic cables are mounted in bores either in the annulus or around the casing or within a pipe. The fixation of the cable in the pipe or in the borehole wall (BL wall) can be carried out in various ways. These include fixing the cable at regular intervals Gluing, riveting and other adhesive bonds as well as fixing on the entire length by gluing. It is also possible to attach the optical fiber cable to certain lengths freely suspended in the tube or in the annulus. The optical waveguides are arranged substantially loop-shaped with vertically extending loop branches in hydraulic lines, in hollow tubes or in hoses, but also in pipes laid by a horizontal drilling method. The cables can consist of different layers and include in addition to a glass fiber and heating wires or protective layers.

There are versions of optical cables for various purposes in the publications DE 199 50 111 C1 and DE 100 52 922 A1 described. The document includes DE 199 50 111 C1 a hybrid sensor cable for fiber optic temperature measurements, in particular for the determination of temperature fields caused by fluid movements or temperature anomalies. The hybrid cable has within the cable core at least one or more fiber optic fibers having loose tube / n and the buffer tube closely adjacent at least one electrical heating line or a cooling medium leading line, the cavities of the cable core are filled with filler and the cable core surrounded by a Bewicklungsfolie is.

Another sensor cable for fiber optic temperature measurements is in the document DE 100 52 922 A1 described, which comprises a cable core with at least one optical waveguide and a reinforcement and / or sheath. Within the cable core, at least one electrical heating line or a line carrying a cooling medium is also arranged here, which is located substantially in the center of the cable. At least one optical waveguide is arranged at the same radial distance from the heating conductor or the cooling conductor or a corresponding line.

• – Füllen der Nut mit einem flüssigen Material,
• – Platzieren der Sensoranordnung in der mindestens einen Nut, um dadurch die Sensoranordnung in Kontakt mit dem flüssigen Material zu bringen,
• – Fixieren der Sensoranordnung in der mindestens einen Nut durch Verfestigen des flüssigen Materials und
• – Verformen des oberen Abschnitts der Nut, so dass die oberen Nutwände näher als die Breite des breitesten Teils des Querschnitts der Sensoranordnung aneinandergebracht werden.

A method for mounting a sensor assembly in a tubular element is in the document US 2004/0 168 521 A1 described, wherein at least one reinforcing layer is provided by helically winding an armored wire on the tubular member, wherein the armored wire is provided with at least one groove therein, wherein the groove comprises a lower portion with lower groove walls and an upper portion with upper groove walls, the lower Section is designed to obtain the widest part of the sensor assembly, the method comprising the following steps.

• Filling the groove with a liquid material,
• Placing the sensor arrangement in the at least one groove, thereby bringing the sensor arrangement into contact with the liquid material,
• - Fixing the sensor assembly in the at least one groove by solidification of the liquid material and
• Deforming the upper portion of the groove such that the upper groove walls are brought closer together than the width of the widest part of the cross section of the sensor assembly.

In the method, an arrangement of the cable in the longitudinal direction is indicated to the tube. A handling of the optical fiber cable at the end of the tube is not described.

• – einer im Wesentlichen flüssigkeitsundurchlässigen Drucksperrschicht,
• – einer aus Fasern und aus einer Matrix zusammengesetzten Schicht, wobei die Schicht und die Drucksperrschicht zusammen eine Wand des Rohrelements bilden,
• – einem Energieleiter, der sich längsweise entlang des Rohrelements ausdehnt und in die Wand des Rohrelements eingebettet ist, und
• – einem Sensor, der in die Wand des Rohrelements eingebracht ist und zu einer Signalkommunikation durch den Energieleiter hindurch verbunden ist, so dass der Sensor auf eine Umweltbedingung des Rohrelements antwortet und kommuniziert mit dem Energieleiter über einen Signalaustausch.

A composite tube member for winding in an open bore configuration into a coil and for unwinding to provide the composite tube member is disclosed WO 99/19653 A1 described, wherein the composite pipe element consists of

• A substantially liquid impervious pressure barrier layer,
• A layer composed of fibers and of a matrix, wherein the layer and the pressure-barrier layer together form a wall of the tubular element,
• - An energy conductor, which extends longitudinally along the tubular element and is embedded in the wall of the tubular element, and
• A sensor which is inserted in the wall of the tubular element and is connected to a signal communication through the energy conductor, so that the sensor responds to an environmental condition of the tubular element and communicates with the energy conductor via a signal exchange.

It is described therein an element which is located at the end of the tube. Thus, a connection of the end-side cables, which protrude from the tube, with other modules feasible, but within the tube, two optical fiber cables can only lead to a sensor located therebetween.

• – auf einem Wickeldorn werden erste Lagen eines aufzuwickelnden Materials, insbesondere eines Bandes oder von Faden aus Glas oder synthetischem Material, bis zu einem bestimmten Durchmesser aufgewickelt und mit Harz getränkt, derart, dass eine Armierung entsteht,
• – nachfolgend wird diese Armierung zumindest soweit ausgehärtet, dass die entstandene Oberfläche mechanisch bearbeitbar ist,
• – in die Oberfläche werden zur Bildung wenigstens eines Kanals eine oder mehrere Nuten eingebracht, die sich vorzugsweise in Längsrichtung oder spiralförmig in der Oberfläche erstrecken,
• – anschließend werden weitere Lagen eines aufzuwickelnden Materials aufgewickelt, bis der Enddurchmesser des Isolierrohres erreicht ist.

A method for producing a wound insulating tube, in particular for a high-voltage insulator is in the document US Pat. No. 6,284,082 B1 in which the insulating tube is provided with at least one channel for subsequently retractable conductors or optical waveguides, the method comprising the following steps:

• On a winding mandrel first layers of a material to be wound, in particular a strip or thread of glass or synthetic material, wound to a certain diameter and impregnated with resin, such that a reinforcement is formed,
• - Subsequently, this reinforcement is cured at least so far that the resulting surface is machinable,
• Into the surface, one or more grooves are introduced to form at least one channel, preferably extending longitudinally or spirally in the surface,
• - Then further layers of a material to be wound up are wound until the final diameter of the insulating tube is reached.

Again, only one arrangement of the optical fiber cable in the longitudinal, axial direction is formed to the tube.

When attaching the optical fiber cable to the pipe according to the conventional procedure, there is the disadvantage that the cable is laid unprotected in the vicinity of a pipe along with its accessories, such as power cables and protective layers. Outside the pipe, chemical or mechanical influences can damage the fiber optic cable and affect its functionality. If the fiber optic cable is routed within the tube, it is exposed to the media within the tube, which may also be chemically aggressive. In addition, the free movement of the media in the pipe through the cable may be impaired here.

When attaching the fiber optic cable, a relatively high effort must be made to attach the fiber optic cable at a constant distance and in parallel alignment with the tube. If this does not succeed, this can lead to an impairment of the measuring accuracy with the cable. In addition to the parallelism and the distance to the tube is to be kept constant. Especially in poorly accessible places of application, such as in boreholes, the uniform attachment of the cable is difficult to implement and control. A standardized attachment of the cable is therefore only possible with difficulty.

When installing the cables, especially in boreholes, the cable can usually only be used for measurements after cementation of the borehole. This makes it difficult to check / monitor the cementation process.

When installing the cable there is the disadvantage that the fiber optic cable can be easily damaged by demolition, crushing or bending.

Since fiber optic cables, which are located outside a pipe or within a pipe, are also exposed to the prevailing environmental conditions, their service life is correspondingly low.

When attaching the cable to the edge of a pipe (inside or outside), the significance of the corresponding measurements made with the cable is mainly limited to one side of the pipe on which the fiber optic cable is located.

The invention has for its object to provide a method for producing tubes with optical fiber cable for measuring environmental relevant variables, which is designed so suitable that at least one optical fiber cable is adapted to a pipe easily and firmly connected to the tube is connected.

• – das Lichtleiterkabel vor den chemischen und mechanischen Beanspruchungen im Rohr sowie um das Rohr herum geschützt werden,
• – der Aufwand für die Anbringung des Kabels beim Installieren des Rohres minimiert werden,
• – eine Beeinträchtigung des Fließverhaltens der Medien im Rohr durch das Kabel verhindert werden,
• – die Ausrichtung/die Anordnung des Lichtleiterkabels relativ zum Rohr angepasst/vereinheitlicht und standardisiert werden,
• – das Lichtleiterkabel bereits zum Beginn einer Zementation für Messungen nutzbar gemacht werden,
• – eine Beschädigung des Lichtleiterkabels vor Abriss, Quetschen und Knicken verhindert werden,
• – die Lebensdauer des Kabels an die des Rohres angepasst werden, was zu einer Erhöhung der Lebensdauer führt,
• – die Aussagekraft der Glasfaserkabelmessungen auf den gesamten Ringraum unabhängig von der Richtung, in der das Kabel am Rohr anliegt, ausgeweitet werden.

In addition, should

• - protecting the fiber optic cable from the chemical and mechanical stresses in the pipe and around the pipe,
• The effort for attaching the cable when installing the pipe is minimized,
• - a deterioration of the flow behavior of the media in the pipe are prevented by the cable,
• The orientation / arrangement of the optical fiber cable relative to the pipe is adjusted / unified and standardized,
• The optical fiber cable can already be used for measurements at the beginning of a cementation,
• - Damage to the optical fiber cable from being torn off, crushed or bent,
• - the life of the cable is adapted to that of the pipe, which leads to an increase in the life,
• - Extend the validity of the fiber optic cable measurements to the entire annulus, regardless of the direction in which the cable abuts the tube.

• – Schaffung einer Ausnehmung innerhalb der Rohrwand,
• – Einbringen des Lichtleiterkabels in die geschaffene Ausnehmung derart, dass das Lichtleiterkabel von der Rohrwand umschlossen wird, und
• – Anbringen mindestens eines Anschlusses des Lichtleiterkabels im anfangsseitigen Rohrbereich an der Rohrwand zur Übergabe von der Lichtsendeeinheit gesendeten Lichtsignalen in das Lichtleiterkabel und zur Übergabe der empfangenen Lichtsignale aus dem Lichtleiterkabel an die Detektionseinheit.

wobei gemäß dem Kennzeichenteil des Patentanspruchs 1
das Lichtleiterkabel in Form einer Schlaufe in eine in der Rohrwand als Schlaufe ausgebildete Ausnehmung eingebracht wird, wobei die Schlaufe in der Rohrwand zumindest im endseitigen Rohrbereich ausgebildet wird,
wobei

• – zwei axial gerichtete schachtartige Ausnehmungen in Form einer freigeschnittenen Längsnut von der Außenfläche der Rohrwand aus in die Rohrwand eingebracht werden, wobei die beiden Längsnuten im endseitigen Rohrbereich durch eine die beiden Enden der Längsnuten verbindenden freigeschnittenen Quernut miteinander zu einer freigeschnittenen Schlaufennut verbunden werden,
• – nachfolgend das Einfügen des Lichtleiterkabels in die freigeschnittene Schlaufennut erfolgt und
• – danach die Schlaufennut mittels eines Nutverschlusses abgedichtet verschlossen wird.

The object is solved by the features of claims 1 and 8. In the method for producing tubes with optical fiber cable for measuring environmental variables, the tube has at least one tube wall which is formed at least with at least one fiber optic cable in communication with the tube, wherein the quantities to be measured in the optical fiber cable detected at least in a portion of the optical fiber cable wherein at least one connection of the optical fiber cable to a light-emitting unit for emitting light signals and to a detection unit for detecting the received light signals is present,
with the following steps,
which are performed to integrate the optical fiber cable within the pipe wall material:

• Creation of a recess within the pipe wall,
• - Introducing the optical fiber cable in the created recess such that the optical fiber cable is enclosed by the pipe wall, and
• - Attaching at least one terminal of the optical fiber cable in the start-side pipe area at the tube wall for the transmission of the light emitting unit sent light signals in the optical fiber cable and for transferring the received light signals from the optical fiber cable to the detection unit.

wherein according to the characterizing part of patent claim 1
the optical fiber cable is introduced in the form of a loop into a recess formed as a loop in the pipe wall, the loop being formed in the pipe wall at least in the end-side pipe region,
in which

• Two axially directed shaft-like recesses in the form of a cut-free longitudinal groove are introduced from the outer surface of the pipe wall into the pipe wall, wherein the two longitudinal grooves in the end pipe region are connected together by a cut-away transverse groove connecting the two ends of the longitudinal grooves to form a cut-out loop groove,
• - Subsequently, the insertion of the optical fiber cable in the cut loop groove takes place and
• - After the Schlaufennut is sealed sealed by a slot closure.

The remaining cavity in the recess can be filled with a filler.

Instead of a pipe wall, a plurality of, in particular two, contacting pipe walls-an outer pipe wall and an inner pipe wall-can be used.

The optical fiber cable can be inserted in the axial direction of the tube axis between the outer tube wall and the inner tube wall in the recess consisting of two part-recesses of the two tube walls, wherein optionally the remaining free cavity of the recess is filled with filler.

The inner tube wall of the tube can be provided with a recess in the form of an arched to the tube axis axially directed fold or a cut groove for receiving the optical fiber cable and the outer tube wall can be applied surface contacting the outer surface of the inner tube wall.

The outer tube wall can further be provided with a recess in the form of a directed away from the tube axis arched fold or a cut groove for receiving the optical fiber cable and the inner tube wall can be applied surface contacting the inner surface of the outer tube wall.

The detection unit can be connected to an evaluation unit and, if appropriate, to a display unit arranged downstream of the evaluation unit.

• – für das schlaufenförmige Lichtleiterkabel zwei axial gerichtete Ausnehmungen in Form jeweils einer Längsnut von der Außenfläche der Rohrwandung aus in die Rohrwandung voneinander beabstandet eingebracht sind, wobei die beiden Längsnuten im endseitigen Rohrbereich durch eine die beiden Enden der Längsnuten verbindenden Quernut zur Ausbildung einer Schlaufennut miteinander verbunden sind,
• – wobei das Lichtleiterkabel in die Schlaufennut eingefügt ist und
• – die Schlaufennut mittels eines Nutverschlusses abgedichtet und verschlossen ist.

The tube produced by the method with optical fiber cable for measuring environmental variables has at least one tube wall and is formed with at least one optical fiber cable, wherein the optical fiber cable at least with a connection for a Lichtsignalsendeeinheit and a detection unit for detecting Meßgrößenensignalen and an evaluation unit for the measured value signals connected is,
wherein in a recess within the tube wall of the tube, the optical fiber cable is arranged protected for detecting the predetermined environment-relevant variables, so that the tube wall in the contact area with the optical fiber cable surrounding the optical fiber cable for integration of the optical fiber cable within the pipe wall material,
wherein according to the characterizing part of claim 8
the optical fiber cable is introduced in the form of a loop into a loop-shaped recess formed in the pipe wall, wherein the loop is formed in the end-side pipe region,
in which

• - For the loop-shaped optical fiber cable two axially directed recesses in the form of a respective longitudinal groove from the outer surface of the pipe wall in the pipe wall are spaced from each other, wherein the two longitudinal grooves in the end-side pipe region connected by a transverse groove connecting the two ends of the longitudinal grooves to form a loop groove are,
• - In which the optical fiber cable is inserted into the loop groove and
• - The loop groove is sealed and closed by means of a slot closure.

The tube wall may consist of at least two tube walls, wherein the outer surface of the inner tube wall contacts the inner surface of the outer tube wall.

Between the inner tube wall and the outer tube wall, a recess may be present, which is composed of a directed to the tube axis concave curvature in the inner tube wall and directed to the tube axis convex curvature in the outer tube wall.

Between the inner tube wall and the outer tube wall may be present a recess which has a tube axis directed concave curvature in the inner tube wall, wherein the curvature on the buckling open side is bounded by the inner surface of the outer tube wall.

Between the inner tube wall and the outer tube wall may be present a recess which has a tube axis directed convex curvature in the outer tube wall, wherein the curvature is limited on the vault open side of the outer surface of the inner tube wall.

The optical fiber cable is led out of the pipe wall or outer pipe wall via the connection in the start-side pipe region and connected to a light-emitting unit for introducing light signals into the optical fiber cable and to a detection unit provided with an evaluation unit for processing the acquired measured values of the environment-relevant variables Evaluation unit is optionally in communication with a downstream display unit.

The light-emitting unit and the detection unit may have a common terminal.

The pipe wall and the pipe walls may be made of metal and / or composite materials according to need and application.

The cavities of the recesses may be filled with filler between the optical fiber cable and the surrounding pipe wall or the surrounding pipe wall (s).

In the tube thus produced with integrated optical fiber cable tube and fiber optic cable can already be combined in the production of the tube according to the method. This includes the fiber optic cable, according to the requirements of the fiber optic cable, already all additional layers, eg. B. protective layers against overstretching, overheating, etc. It can also be introduced heating wires to it.

The combination is done by inserting the fiber optic cable into the wall of the tube so that the tubing is around the fiber optic cable. The fiber optic cable thus has no contact either with the outside space around the tube or with the hollow space inside the tube.

The fiber optic cable integrated in the tube wall is not limited to just one fiber optic cable; according to the invention, it is also possible for a plurality of fiber optic cables to be introduced within the tube wall as required.

Further developments and special embodiments of the invention are specified in further subclaims.

The invention will be explained with reference to several embodiments by means of several drawings.

Show it:

1 a perspective view of a tube with a plurality of layer-like tube walls according to the prior art,

2 a schematic perspective view of a fiber optic cable containing tube with an introduced within the pipe wall optical fiber cable for use in on-site measurements of environmental variables with connections to a light emitting unit and to a detection unit with downstream evaluation and a measured value display unit,

3 a schematic representation of a section AA of the cross section through a fiber optic cable containing tube with a thick tube wall after 2 wherein the optical fiber cable is located within an axially directed longitudinal recess and an axially directed groove closure closing the longitudinal recess,

4 a schematic representation of a section of the cross section through an optical fiber cable containing tube with two tube walls - an inner tube wall and an outer tube wall -, wherein the optical fiber cable is arranged approximately centrally between the two tube walls,

5 a schematic representation of a section of the cross section through a fiber optic cable containing tube with two tube walls, wherein the optical fiber cable between the two tube walls and disposed adjacent to the outer surface of the inner tube wall,

6 a schematic representation of a section of the cross section through a fiber optic cable containing tube with two tube walls, wherein the optical fiber cable between the two tube walls and is arranged adjacent to the inner surface of the outer tube wall.

The following are the 2 and 3 considered together. In 2 is a schematic representation of a pipe 2 with integrated fiber optic cable 3 shown to measure environmental variables, the pipe 2 at least one pipe wall 4 and with at least one optical fiber cable 3 is formed, wherein the Optical fiber cable 3 outside the tube 2 at least with a connection 16 and or 17 to the light signal transmission unit 18 and a detector unit 19 for the acquisition of measured variable signals and an evaluation unit 20 is connected for the detected measured variable signals.

In a recess 7 . 72 inside the pipe wall 4 of the pipe 2 at least in the end pipe area 14 is the fiber optic cable 3 arranged to capture the predetermined environmental variables, so that the pipe wall 4 in the contact area with the fiber optic cable 3 the fiber optic cable 3 surrounds, allowing an integration of the fiber optic cable 3 is present within the pipe wall material.

This in 2 in a schematic perspective view shown optical fiber cable 3 containing pipe 2 with the inside of the pipe wall 4 introduced optical fiber cable 3 In the case of a geothermal probe, it can be used to extract geothermal energy from the subsurface, while the fiber optic cable 3 with connection 16 and / or connection 17 to the light-emitting unit 18 as well as to the detection unit 19 with subordinate evaluation unit 20 and a final measured value display unit 21 for use in on-site measurements of environmental variables in a borehole 15 serves. The data from the measurement can then be used, for example, to optimize the operation of geothermal probes. The connections 16 and or 17 can at the side positions 161 . 171 of the pipe 2 or at the positions 162 . 172 at the beginning of the pipe area 28 of the pipe 2 lie.

According to the invention, the optical fiber cable 3 in the form of a loop 72 in one in the pipe wall 4 ; 5 . 6 loop-shaped recess 7 introduced, with the loop 72 in the end pipe area 14 is trained.

When using a linear fiber optic cable 3 in a homogeneous tube wall 4 can, as in 3 is shown, an axially directed recess 7 in the form of a cut longitudinal groove 71 from the outside surface 22 the pipe wall 4 out into the pipe wall 4 be introduced, wherein the optical fiber cable 3 in the cut longitudinal groove 71 is inserted and the longitudinal groove 71 by means of a slot closure 13 sealed sealed.

For the loop-shaped optical cable 3 according to 2 under consideration of 3 are according to the invention in the homogeneous tube wall 4 two axially directed recesses in the form of a respective longitudinal groove 71 from the outside surface 22 the pipe wall 5 out into the pipe wall 5 introduced spaced apart. Here are the two longitudinal grooves 71 in the pipe area 14 through one of the two ends of the longitudinal grooves 71 connecting transverse groove 73 with the formation of a loop groove 72 connected with each other. The fiber optic cable 3 is in the loop groove 72 inserted and the loop groove 72 is by means of a slot closure 13 sealed and closed.

The pipe wall 4 can according to the 4 . 5 . 6 also consist of at least two pipe walls, the outer surface 12 the inner pipe wall 6 the inner surface 11 the outer pipe wall 5 touched.

Between the inner pipe wall 6 and the outer tube wall 5 can at least one recess 7 be present according to 4 from a partial recess 27 with one to the tube axis 23 concave curvature 24 in the inner tube wall 6 and a partial recess 26 with one to the tube axis 23 convex curvature 25 in the outer tube wall 5 forms.

Between the inner pipe wall 6 and the outer tube wall 5 can according to 5 a recess 7 be present, resulting from a partial recess 27 with one to the tube axis 23 concave curvature 24 in the inner tube wall 6 forms, with the curvature 24 on the vault-open side of the inner surface 11 the outer pipe wall 6 is limited.

Between the inner pipe wall 6 and the outer tube wall 5 can further according to 6 a recess 7 be present, resulting from a partial recess 26 with one to the tube axis 23 convex curvature 25 in the outer tube wall 6 forms, with the curvature 25 on the vault-open side of the outer surface 12 the inner pipe wall 6 is limited.

The fiber optic cable 3 can outside the tube 2 from the pipe wall 4 according to 2 and 3 or pipe wall 6 according to the 4 . 5 and 6 over the connection 16 and / or connection 17 to a light-emitting unit 18 for introducing light signals into the optical fiber cable 3 and to a detection unit provided for acquiring measured values 19 with connected evaluation unit 20 be carried out for processing the acquired measurements of the environmental variables and, where appropriate, the evaluation unit 20 with a downstream display unit 21 keep in touch. The light-emitting unit 18 and the detection unit 19 can share a connection 16 or 17 to have.

The homogeneous pipe wall 4 and the pipe walls 5 . 6 can be made of metal and / or Composite materials according to need and application exist.

The remaining cavities of the recesses 7 . 71 . 72 . 73 between the fiber optic cable 3 and the surrounding pipe wall 4 or the surrounding pipe wall (s) 5 . 6 can with filler material 8th according to 3 . 4 . 5 and 6 be filled.

In the 3 . 4 . 5 and 6 are schematic representations of some examples of integration possibilities of the optical fiber cable 3 shown in a pipe wall. The dimensions of the cable-related bulges in the pipe wall are shown elevated. The vaults of the pipe walls 4 ; 5 . 6 in principle or inward can in principle also be removed, preferably ground off.

• a) Anbringung in einer freigeschnittenen Ausnehmung 7, 71 in Längsrichtung eines massiven Rohres 2. Hier bleibt der Rohrdurchmesser konstant, die Stabilität des Rohres 2 ist jedoch herabgesetzt. Dazu ist in 3 eine schematische Darstellung eines Ausschnitts des Querschnitts durch das das Lichtleiterkabel 3 enthaltende Rohr 2 mit einer dicken Rohrwand 4 nach 2 gezeigt, wobei sich das Lichtleiterkabel 3 gemäß 3 innerhalb einer axial gerichteten Längsausnehmung 7, 71 und einer die Längsausnehmung 71 verschließenden axial gerichteten Nutverschluss 13 befindet.
• b) Anbringung im Zentrum der Rohrwand aus zwei Rohrwandungen 5, 6 mit einer geringen Verkleinerung des inneren Rohrdurchmessers und einer geringen Vergrößerung des äußeren Rohrdurchmessers. Dazu ist in 4 eine schematische Darstellung eines Ausschnitts des Querschnitts durch das das Lichtleiterkabel 3 enthaltende Rohr mit zwei Rohrwandungen – einer inneren Rohrwandung 6 und einer äußeren Rohrwandung 5 – gezeigt, wobei das Lichtleiterkabel 3 etwa mittig zwischen den beiden Rohrwandungen 5, 6 angeordnet ist.
• c) Anbringung am inneren Bereich der Rohrwandung 6 mit einer Wölbung des Rohres 2 nach innen. Das führt zu einer Verkleinerung des inneren Rohrdurchmessers. Dazu ist in 5 eine schematische Darstellung eines Ausschnitts des Querschnitts durch das das Lichtleiterkabel 3 enthaltende Rohr 2 mit zwei Rohrwandungen 5, 6 gezeigt, wobei das Lichtleiterkabel 3 zwischen den beiden Rohrwandungen 5, 6 und an der Außenfläche 12 der inneren Rohrwandung 6 anliegend angeordnet ist.
• d) Anbringung am äußeren Bereich der Rohrwandung 5 mit einer Wölbung des Rohres 2 nach außen. Dies führt zu einer Vergrößerung des äußeren Rohrdurchmessers. Das Füllmaterial 8 in dem verbleibenden Hohlraum ist den Betriebsbedingungen des Rohres 2 angepasst. Dazu ist in 6 eine schematische Darstellung eines Ausschnitts des Querschnitts durch das das Lichtleiterkabel 2 enthaltende Rohr 2 mit zwei Rohrwandungen 5, 6 gezeigt, wobei das Lichtleiterkabel 3 zwischen den beiden Rohrwandungen 5, 6 und an der Innenfläche 11 der äußeren Rohrwandung 5 anliegend angeordnet ist.

Following integrations of the optical fiber cable 3 may be possible:

• a) attachment in a cut-free recess 7 . 71 in the longitudinal direction of a massive tube 2 , Here, the pipe diameter remains constant, the stability of the pipe 2 but is lowered. This is in 3 a schematic representation of a section of the cross section through the optical fiber cable 3 containing pipe 2 with a thick tube wall 4 to 2 shown, with the fiber optic cable 3 according to 3 within an axially directed longitudinal recess 7 . 71 and one the longitudinal recess 71 closing axially directed slot closure 13 located.
• b) Attachment in the center of the pipe wall from two pipe walls 5 . 6 with a small reduction in the inner tube diameter and a small increase in the outer diameter of the tube. This is in 4 a schematic representation of a section of the cross section through the optical fiber cable 3 containing pipe with two pipe walls - an inner pipe wall 6 and an outer tube wall 5 - shown, with the fiber optic cable 3 approximately in the middle between the two pipe walls 5 . 6 is arranged.
• c) attachment to the inner area of the pipe wall 6 with a curvature of the pipe 2 inside. This leads to a reduction of the inner pipe diameter. This is in 5 a schematic representation of a section of the cross section through the optical fiber cable 3 containing pipe 2 with two pipe walls 5 . 6 shown, with the fiber optic cable 3 between the two pipe walls 5 . 6 and on the outside surface 12 the inner pipe wall 6 is arranged adjacent.
• d) attachment to the outer region of the pipe wall 5 with a curvature of the pipe 2 outward. This leads to an enlargement of the outer pipe diameter. The filling material 8th in the remaining cavity is the operating conditions of the pipe 2 customized. This is in 6 a schematic representation of a section of the cross section through the optical fiber cable 2 containing pipe 2 with two pipe walls 5 . 6 shown, with the fiber optic cable 3 between the two pipe walls 5 . 6 and on the inside surface 11 the outer pipe wall 5 is arranged adjacent.

• – Schaffung einer Ausnehmung 7, 71, 72, 73 innerhalb der Rohrwand 4 bzw. Rohrwandungen 5, 6,
• – Einbringen des Lichtleiterkabels 3 in die geschaffene Ausnehmung 7, 71, 72, 73, wobei das Lichtleiterkabel 3 von der Rohrwand 4; 5, 6 umschlossen ist,
• – Anbringen eines Anschlusses 16 und/oder 17 des Lichtleiterkabels 3 an der Rohrwand 4 oder je nach Rohrwandausbildung an der äußeren Rohrwandung 5 zur Übergabe von gesendeten Lichtsignalen in das Lichtleiterkabel 3 und zur Übergabe der erfassten empfangenen Lichtsignale aus dem Lichtleiterkabel 3.

In the method of manufacturing pipes 2 with integrated fiber optic cable 3 to measure environmental variables is the pipe 2 with at least one pipe wall 4 ; 5 . 6 and at least one with the pipe 2 related fiber optic cable 3 formed, wherein the measured quantities at least in a portion of the optical fiber cable 3 or along the entire fiber optic cable 3 are detectable. In addition, connections are 16 on the positions 161 . 162 and or 17 on the positions 171 . 172 to a light-emitting unit 18 for emitting light signals and to a detector unit 19 for detecting the received light signals to the optical fiber cable 3 attached, and it
be following steps
for the integration of the optical fiber cable 3 carried out inside the pipe wall material:

• - Creating a recess 7 . 71 . 72 . 73 inside the pipe wall 4 or pipe walls 5 . 6 .
• - Insertion of the optical fiber cable 3 in the created recess 7 . 71 . 72 . 73 where the fiber optic cable 3 from the pipe wall 4 ; 5 . 6 is enclosed
• - Attaching a connection 16 and or 17 of the optical fiber cable 3 on the pipe wall 4 or depending on the pipe wall formation on the outer pipe wall 5 for the transmission of transmitted light signals in the optical fiber cable 3 and for transferring the detected received light signals from the optical fiber cable 3 ,

According to the invention, the optical fiber cable 3 according to 2 in the form of a loop in one in the pipe wall 4 ; 5 . 6 as a loop 72 trained recess 7 introduced, with the loop 72 in the pipe wall 4 ; 5 . 6 in the end pipe area 14 is trained.

• – zwei axial gerichtete Ausnehmungen 7, 71 in Form einer freigeschnittenen Längsnut 71 von der Außenfläche 22 der Rohrwand 4 aus in die Rohrwand 4 eingebracht, wobei die beiden Längsnuten 71 im endseitigen Rohrbereich 14 durch eine die beiden Enden der Längsnuten 71 verbindenden freigeschnittenen Quernut 73 miteinander zu einer freigeschnittenen Schlaufennut 72 verbunden werden,
• – nachfolgend das Einfügen des Lichtleiterkabels 3 in die freigeschnittene Schlaufennut 72 durchgeführt und
• – danach die Schlaufennut 72 mittels eines Nutverschlusses 13 abgedichtet und verschlossen.

It will

• - Two axially directed recesses 7 . 71 in the form of a cut longitudinal groove 71 from the outside surface 22 the pipe wall 4 out into the pipe wall 4 introduced, wherein the two longitudinal grooves 71 in the end pipe area 14 through one of the two ends of the longitudinal grooves 71 Joining cutaway cross groove 73 to each other a cut loop groove 72 get connected,
• - below the insertion of the optical fiber cable 3 into the cut-out loop groove 72 performed and
• - then the loop groove 72 by means of a slot closure 13 sealed and closed.

The remaining remaining cavity in the recess 7 . 71 . 72 . 73 can before closing the groove with a filler 8th be filled.

Instead of a pipe wall 4 may preferably be two contacting pipe walls - an outer pipe wall 5 and an inner tube wall 6 - be used. This can be the recesses 7 . 71 . 72 . 73 and the fiber optic cable 3 analogous to the homogeneous tube wall 4 be designed as executed there.

In this case, the optical fiber cable 3 in the axial direction to the tube axis 23 between the outer pipe wall 5 and the inner tube wall 6 into the recess 7 are inserted, optionally with the remaining free cavity of the recess 7 with filler 8th is filled.

The inner pipe wall 6 the pipe 2 can with a recess 7 , the partial recess 27 , in the form of a tube axis 23 arched axially directed fold 9 or a cut groove for receiving the fiber optic cable 3 be provided and the outer pipe wall 5 on the outside surface 12 the inner pipe wall 6 be applied surface contacting.

The outer pipe wall 5 can with a recess 7 , the partial recess 26 , in the shape of one of the tube axis 23 Away arched fold 10 or a cut groove for receiving the fiber optic cable 3 be provided and the inner tube wall 6 on the inner surface 11 the outer pipe wall 5 be applied surface contacting.

• – Das Rohr 2 kann eine massive Rohrwand 4 haben, so dass die Stelle für das Lichtleiterkabel 3 mit einem länglichen linearen Freischnitt 71 versehen wird. In diesem Fall wird oberhalb des Lichtleiterkabels 3 dann ein Verschluss 13 aufgebracht. Das Rohr 2 kann an dieser linearen Ausnehmung an Stabilität verlieren. Insofern ist dieses Verfahren nur an besonders dicken Rohren 4 anwendbar, beispielsweise bei Pipelines.
• – Das Rohr 4 kann aus mindestens zwei Rohrwandungen 5, 6 bestehen. In diesem Falle kann das Kabel 3 bereits in der Herstellung des Rohres 2 zwischen die zwei schichtartigen Rohrwandungen 5, 6 gelegt werden, wobei im Falle von geothermischen Sonden sich dieses Verfahren beispielsweise dort anbietet, wo auf Kupferrohren zum Schutz eine Kunststoffbeschichtung aufgebracht wird. Dort kann das Lichtleiterkabel 3 zwischen Kupfer und Kunststoff gelegt werden, wo es fixiert ist. Bei Rohren aus Verbundmaterial ist es sogar möglich, das Lichtleiterkabel 3 zwischen metallische Rohrwandungen zu legen.

That's the fiber optic cable 3 surrounding material of the pipe 2 Can for attaching the fiber optic cable 3 be as follows:

• - The pipe 2 can be a massive pipe wall 4 have, so the body for the fiber optic cable 3 with an elongated linear cutout 71 is provided. In this case, above the fiber optic cable 3 then a lock 13 applied. The pipe 2 can lose stability at this linear recess. In this respect, this procedure is only on particularly thick pipes 4 applicable, for example in pipelines.
• - The pipe 4 can consist of at least two pipe walls 5 . 6 consist. In this case, the cable can 3 already in the production of the pipe 2 between the two layered tube walls 5 . 6 In the case of geothermal probes, this method, for example, offers where a plastic coating is applied to copper pipes for protection. There can be the fiber optic cable 3 be placed between copper and plastic, where it is fixed. In composite pipes it is even possible to use the fiber optic cable 3 to place between metallic pipe walls.

The advantage of direct contact of the fiber optic cable 3 to metallic layers 5 . 6 a pipe 2 consists in the high thermal conductivity of metal. In the event that a temperature change on one side of the tube 2 takes place, this spreads quickly over the entire circumference of the tube 2 out. This can be the cable 3 DTS process, regardless of the position of the fiber optic cable 3 in the pipe 2 , Temperature fluctuations around the pipe 2 register around. This speaks in particular for a combination of the optical fiber cable 3 with the metallic layered tube walls 5 . 6 ,

By fixing the optical fiber cable 3 between two pipe walls 5 . 6 in the pipe 2 can be ensured that the fiber optic cable 3 its position relative to the pipe 2 reserves. This ensures that the distance and collinearity of the fiber optic cable 3 to the pipe 2 exactly adhered to.

There is also an installation of the fiber optic cable 3 already after an installation of the pipe 2 largely completed. It only needs the connection of the optical fiber cable 3 via the detection unit 19 to the evaluation unit 20 for the DTS process and the fiber optic cable 3 must be calibrated. Both steps can be done by the usual method.

Conventional is a loose fiber optic cable during the installation process in the borehole 15 particularly at risk. In the tube 2 taken in installation is the fiber optic cable 3 however, protected from chemical and mechanical stresses, unless the pipe 2 is kinked or so badly damaged that the fiber optic cable 3 is free. In both cases, the tube should 2 even useless.

Because the fiber optic cable 3 inside the pipe wall 4 ; 5 . 6 Protected, can with a higher life expectancy of the optical fiber cable 3 be calculated as with freely laid fiber optic cables. In addition, this is a damage to the optical fiber cable 3 by kinking, squeezing or bending in the borehole 15 unlikely.

Because the fiber optic cable 3 already with the introduction of the tube 2 is functional, it can already during the process of cementation of the pipe 2 to monitor cementation. Normally, the exposed optical fiber cable can hinder the cementation process. In addition, it is usually moved during cementation, which makes a calibration obsolete.

The combination of fiber optic cables 3 over several pipes or pipe sections can happen over the usual procedures, such as plugs, screw connections, Präzisionsverspleißen.

The essence of the invention is the introduction of the optical fiber cable 3 in the pipe wall 4 / in / between the pipe walls 5 . 6 of the pipe 2 by removing the fiber optic cable 3 already during the construction of the pipe 2 in the pipe wall 4 / in / between the pipe walls 5 . 6 introduced and ultimately the protective material of the pipe wall 4 . 5 . 6 is surrounded.

The invention facilitates the incorporation of fiber optic / fiber optic cables in wellbores 15 , Pipes and pipelines and improves the quality of the installation. In addition, by the invention, the optical fiber cable 3 earlier than conventional downhole 15 be used. This is a monitoring of boreholes 15 by means of the DTS (Distributed Temperature Sending) method already possible in the construction phase. The type of attachment makes the fiber optic cable 3 very resistant. Thus, impairments due to chemical and mechanical influences can be prevented.

The invention also allows the attachment of the optical fiber cable 3 be standardized, indicating the accuracy of DTS measurements with the fiber optic cable 3 improved. The invention also ensures that the operation of a wellbore 15 through the fiber optic cable 3 is not affected and that the fiber optic cable 3 over the entire period of use of the borehole 15 remains functional.

In addition, the invention avoids a device-dependent information content of fiber optic cables, which consists of the attachment of the optical fiber cable 3 on only one side of the tube (inside or outside) results. This makes it possible to make a statement about the entire annulus from a measurement, regardless of where in the pipe / well 15 the fiber optic cable 3 is applied.

LIST OF REFERENCE NUMBERS

1

Composite pipe

2

pipe

3

Optical fiber cable

4

thick tube wall / homogeneous tube wall

5

outer pipe wall

6

inner pipe wall

7

recess

71

cut longitudinal groove / shaft

72

Schlaufennut

73

transverse groove

8th

filler

9

First arched fold

10

Second arched fold

11

Inner surface of the outer pipe wall

12

Outer surface of the inner tube wall

13

slot closure

14

End-side pipe area

15

well

16

First connection

161

Lateral position

162

Position at the start-side pipe area

17

Second connection

171

Lateral position

172

Position at the start-side pipe area

18

Light-emitting unit

19

detection unit

20

evaluation

21

display unit

22

Outer surface of the pipe wall

23

pipe axis

24

Concave curvature

25

Convex curvature

26

Partial recess

27

Partial recess

28

start-side pipe area

30

first PE-RT wall

31

first coat of adhesion promoter

32

metallic wall

33

second layer of adhesion promoter

34

second PE-RT wall

Claims (17)

Method for producing pipes ( 2 ) with fiber optic cable ( 3 ) for measuring environmental variables, the tube ( 2 ) at least one pipe wall ( 4 ; 5 . 6 ), which at least at least one with the pipe ( 2 ) in conjunction optical fiber cable ( 3 ) is formed, wherein in the optical fiber cable ( 3 ) to be measured at least in a section of the optical fiber cable ( 3 ), at least one connection ( 16 . 17 ) of the optical fiber cable ( 3 ) to a light emitting unit ( 18 ) for emitting light signals and to a detection unit ( 19 ) is present for detecting the received light signals, with the following steps, for the integration of the optical fiber cable ( 3 ) within the pipe wall material: - creation of a recess ( 7 ) within the pipe wall ( 4 ; 5 . 6 ), - insertion of the optical fiber cable ( 3 ) in the created recess ( 7 ) such that the optical fiber cable ( 3 ) from the pipe wall ( 4 ; 5 . 6 ), and - attaching at least one connection ( 16 ; 17 ) of the optical fiber cable ( 3 ) in the start-side pipe region ( 28 ) on the pipe wall ( 4 ) for transfer from the light-emitting unit ( 18 ) transmitted light signals in the optical fiber cable ( 3 ) and for transferring the received light signals from the optical fiber cable ( 3 ) to the detection unit ( 19 ) characterized in that the optical fiber cable ( 3 ) in the form of a loop in one in the pipe wall ( 4 ; 5 . 6 ) as a loop ( 72 ) formed recess ( 7 ), wherein the loop ( 72 ) in the pipe wall ( 4 ; 5 . 6 ) at least in the end pipe region ( 14 ), wherein - two axially directed shaft-like recesses ( 7 . 71 ) in the form of a cut-free longitudinal groove ( 71 ) from the outer surface ( 22 ) of the pipe wall ( 4 ) out into the pipe wall ( 4 ), wherein the two longitudinal grooves ( 71 ) in the end pipe region ( 14 ) by one of the two ends of the longitudinal grooves ( 71 ) connecting cut-away transverse groove ( 73 ) with each other to a free-cut loop groove ( 72 ), - subsequently the insertion of the optical fiber cable ( 3 ) into the cut-out loop groove ( 72 ) and - after that the loop groove ( 72 ) by means of a slot closure ( 13 ) is sealed sealed. A method according to claim 1, characterized in that the remaining cavity in the recess ( 7 . 71 . 72 . 73 ) with a filler ( 8th ) is filled. A method according to claim 1, characterized in that instead of a pipe wall ( 4 ) several, in particular two contacting pipe walls - an outer pipe wall ( 5 ) and an inner tube wall ( 6 ) - be used. Method according to claim 3, characterized in that the optical fiber cable ( 3 ) in the axial direction to the tube axis ( 23 ) between the outer pipe wall ( 5 ) and the inner tube wall ( 6 ) into the two partial recesses ( 26 . 27 ) of the two pipe walls ( 6 . 5 ) existing recess ( 7 ) is inserted, optionally with the remaining free cavity of the recess ( 7 ) with filler ( 8th ) is filled. Method according to claim 3, characterized in that the inner tube wall ( 6 ) of the pipe ( 2 ) with a recess ( 7 ) in the form of a tube axis ( 23 ) arched axially directed fold ( 9 ) or a cut groove for receiving the optical fiber cable ( 3 ) and the outer pipe wall ( 5 ) on the outer surface ( 12 ) of the inner pipe wall ( 6 ) is applied surface contacting. Method according to claim 3, characterized in that the outer pipe wall ( 5 ) with a recess ( 7 ) in the form of a pipe axis ( 23 ) directed arched fold ( 10 ) or a cut groove for receiving the optical fiber cable ( 3 ) and the inner tube wall ( 6 ) on the inner surface ( 11 ) of the outer pipe wall ( 5 ) is applied surface contacting. Method according to claim 1, characterized in that the detection unit ( 19 ) to an evaluation unit ( 20 ) and optionally to one of the evaluation unit ( 20 ) downstream display unit ( 21 ) is connected. Pipe ( 2 ) with fiber optic cable ( 3 ) for measuring environmental variables, the tube ( 2 ) at least one pipe wall ( 4 ; 5 . 6 ) and with at least one optical fiber cable ( 3 ), wherein the optical fiber cable ( 3 ) at least with a connection for a light signal transmission unit ( 18 ) and a detection unit ( 19 ) for the acquisition of measured variable signals and an evaluation unit ( 20 ) according to the method of any one of claims 1 to 7, wherein in a recess ( 7 . 71 . 72 . 73 ) within the pipe wall ( 4 ; 5 . 6 ) of the pipe ( 2 ) the fiber optic cable ( 3 ) is arranged protected to detect the predetermined environmental variables, so that the pipe wall ( 4 ) in the contact area with the optical fiber cable ( 3 ) the fiber optic cable ( 3 ) for the integration of the optical fiber cable ( 3 ) Surrounds within the pipe wall material, characterized in that the optical-fiber cable ( 3 ) in the form of a loop ( 72 ) in one in the pipe wall ( 4 ; 5 . 6 ) loop-shaped recess ( 7 ), wherein the loop ( 72 ) in the end pipe region ( 14 ) is formed, wherein - for the loop-shaped optical fiber cable ( 3 ) two axially directed recesses in the form of a respective longitudinal groove ( 71 ) from the outer surface ( 22 ) of the pipe wall ( 5 ) out into the pipe wall ( 5 ) are spaced from each other, wherein the two longitudinal grooves ( 71 ) in the end pipe region ( 14 ) by one of the two ends of the longitudinal grooves ( 71 ) connecting transverse groove ( 73 ) for forming a loop groove ( 72 ), wherein the optical fiber cable ( 3 ) into the loop groove ( 72 ) is inserted and - the loop groove ( 72 ) by means of a slot closure ( 13 ) is sealed and closed. Pipe according to claim 8, characterized in that the pipe wall ( 4 ) consists of at least two pipe walls, wherein the outer surface ( 12 ) of the inner pipe wall ( 6 ) the inner surface ( 11 ) of the outer pipe wall ( 5 ) touched. Pipe according to claim 9, characterized in that between the inner pipe wall ( 6 ) and the outer tube wall ( 5 ) a recess ( 7 ), which is composed of a tube axis ( 23 ) directed concave curvature ( 24 ) in the inner tube wall ( 6 ) and one to the tube axis ( 23 ) directed convex curvature ( 25 ) in the outer tube wall ( 5 ). Pipe according to claim 9, characterized in that between the inner pipe wall ( 6 ) and the outer tube wall ( 5 ) a recess ( 7 ), one to the tube axis ( 23 ) directed concave curvature ( 24 ) in the inner tube wall ( 6 ), wherein the curvature ( 24 ) on the vault-open side of the inner surface ( 11 ) of the outer pipe wall ( 6 ) is limited. Pipe according to claim 9, characterized in that between the inner pipe wall ( 6 ) and the outer tube wall ( 5 ) a recess ( 7 ), one to the tube axis ( 23 ) directed convex curvature ( 25 ) in the outer tube wall ( 6 ), wherein the curvature ( 25 ) on the vault-open side of the outer surface ( 12 ) of the inner pipe wall ( 6 ) is limited. Pipe according to claims 8 to 12, characterized in that the optical fiber cable ( 3 ) in the start-side pipe region ( 28 ) from the pipe wall ( 4 ) or outer tube wall ( 5 ) over the connection ( 16 ; 17 ) and to a light-emitting unit ( 18 ) for the introduction of light signals into the optical fiber cable ( 3 ) and to a detection unit provided for the acquisition of measured values ( 19 ) with connected evaluation unit ( 20 ) is connected to the processing of the acquired measured values of the environment-relevant variables and the evaluation unit ( 20 ) optionally with a downstream display unit ( 21 ). Pipe according to claims 8 to 13, characterized in that the light-emitting unit ( 18 ) and the detection unit ( 19 ) have a common connection. Pipe according to claims 8 to 14, characterized in that the pipe wall ( 4 ) and the pipe walls ( 5 . 6 ) made of metal and / or composite materials according to need and application. Pipe according to claims 8 to 15, characterized in that the cavities of the recesses ( 7 . 71 . 72 . 73 ) between the fiber optic cable ( 3 ) and the surrounding pipe wall ( 4 ) or the surrounding pipe wall (s) ( 5 . 6 ) with filler ( 8th ) are filled. Pipe according to claims 8 to 16, characterized in that a plurality of optical fiber cables ( 3 ) as required within the pipe wall ( 4 ; 5 . 6 ) are introduced.

Images