Liquid leak detecting line

Abstract

The present invention addresses the problem of providing a liquid leakage detection line capable of suppressing erroneous detection while suppressing a significant decrease in liquid leakage detection performance. In order to solve the problem, the liquid leakage detection line is provided with a plurality of detection lines, each detection line is provided with a conductor and a woven body covering the conductor, the plurality of detection lines include a first detection line and a second detection line, and the woven body is composed of a yarn having electrical insulation properties. And a woven body through which a liquid showing electrical conductivity is electrically connected to the conductor of the first detection line and the conductor of the second detection line, thereby detecting the liquid, the woven body of one or both of the first detection line and the second detection line is provided with a first yarn and a second yarn intersecting the first yarn, and the second yarn is thinner than the first yarn.

Description

(19) State Intellectual Property Office (12) Invention Patent Application (10) Application Publication Number (43) Application Publication Date (21) Application Number 202480057399.9 (22) Application Date 2024.08.23 (30) Priority Data 2023-202477 2023.11.30 JP (85) PCT International Application Entering National Phase Date 2026.03.09 (86) PCT International Application Application Data PCT / JP2024 / 029934 2024.08.23 (87) PCT International Application Publication Data WO2025 / 115314 JA 2025.06.05 (71) Applicant: Takushida Electric Wire Co., Ltd. Address: Japan (72) Inventors: Satoko Nonaka, Hiroshi Araki (74) Patent Agency: Beijing J&J Intellectual Property Agency Co., Ltd. 11227 Patent Attorney Hu Nairui (51) Int.Cl. G01M 3 / 16 (2006.01) (54) Invention Title: Leakage Detection Line (57) Abstract: The object of the present invention is to provide a leakage detection line that can suppress false detection while suppressing a significant decrease in leakage detection capability. To solve the above-mentioned problem, a leakage detection line is provided, which has a plurality of detection lines, each having a conductor and a braid covering the conductor. The plurality of detection lines includes a first detection line and a second detection line. The braid is made of electrically insulating yarn. A conductive liquid passes through the braid to electrically connect the conductor of the first detection line and the conductor of the second detection line, thereby detecting the liquid. The braid of one or both of the first detection line and the second detection line has a first yarn and a second yarn intersecting the first yarn, wherein the second yarn is thinner than the first yarn. Claims 1 page, Description 14 pages, Drawings 2 pages, CN 121794555 A 2026.04.03 CN 1 21 79 45 55 A 1. A leakage detection line, the leakage detection line comprising a plurality of detection lines, the detection line comprising a conductor and a braid covering the conductor, the plurality of detection lines including a first detection line and a second detection line, the braid being composed of electrically insulating yarn, a conductive liquid passing through the braid electrically connecting the conductor of the first detection line to the conductor of the second detection line, thereby detecting the liquid, characterized in that the braid of one or both of the first detection line and the second detection line comprises a first yarn and a second yarn intersecting the first yarn, the second yarn being thinner than the first yarn. 2. The leakage detection line according to claim 1, characterized in that the first yarn is a monofilament yarn or multifilament yarn with a diameter of 0.2 mm or more and 0.3 mm or less.The second yarn is a monofilament yarn or multifilament yarn with a diameter of 0.05 mm or more and less than 0.2 mm. 3. The leakage detection line according to claim 2, characterized in that the first yarn in the braid has 1 ply, and the second yarn has 1 ply. 4. The leakage detection line according to any one of claims 1 to 3, characterized in that, the conductor is covered by the braid in such a manner as to satisfy the following inequality (1), with a length occupancy rate ≤ 45% … (1) Length occupancy rate = {(Wn1×Cn1×D1) / P1+(Wn2×Cn2×D2) / P2}×100%, Wn1 = number of plies of the first yarn, Wn2 = number of plies of the second yarn, Cn1 = number of yarn tubes of the first yarn, Cn2 = number of yarn tubes of the second yarn, D1 = diameter of the first yarn (mm), D2 = diameter of the second yarn (mm), P1 = wrapping pitch of the first yarn in the length direction of the detection line (mm), P2 = wrapping pitch of the second yarn in the length direction of the detection line (mm). Claims 1 / 1 Page 2 CN 121794555 A Cross-Reference to Related Applications for Leak Detection Lines

[0001] This application claims priority to Japanese Patent Application No. 2023-202477, which is incorporated herein by reference. Technical Field

[0002] The present invention relates to leak detection lines. Background Art

[0003] Conventionally, leak detection lines as shown in Patent Document 1 have been used to detect leaks from pipes or other liquids that exhibit conductivity, such as water supply pipes. As such leak detection lines, leak detection lines with the following configuration are known: multiple detection lines are provided, each detection line having a conductor and a braid covering the conductor. The braid is made of electrically insulating yarn. Under normal circumstances, the braid ensures electrical insulation between the conductors. When liquid leaks from pipes or other liquids, the liquid electrically connects the conductors of one detection line to the conductors of another detection line through the braid, thereby detecting the leak. In addition, as such leak detection lines, detection lines with an outer braid that bundles the detection lines are known.

[0004] For example, in cases where the leak detection line is installed along a piping, it is sometimes installed across sections where the piping is connected by flanges. Furthermore, leak detection lines are often laid in confined spaces. Therefore, leak detection lines with excellent flexibility are used as leak detection lines.

[0005] Patent Document 1: Japanese Utility Model Publication No. 6-35294

[0006] In leak detection lines, there is a problem where accidental electrical connection between the conductors of two detection lines can lead to false detection of a leak even when no leak has occurred, and countermeasures are being sought. In solving this problem, a method can be considered...A detection line is constructed by covering the conductor with a braided material with mesh blocking. However, this approach can lead to poor electrical connection between conductors when the leakage is small, potentially resulting in a significant reduction in leakage detection accuracy. Furthermore, no effective means to address this problem has been provided to date. Therefore, the objective of this invention is to provide a leakage detection line that can suppress false detections while simultaneously mitigating a significant reduction in leakage detection accuracy.

[0007] To solve the above-mentioned problems, the present invention provides a leakage detection line.

[0008] The leakage detection line includes a plurality of detection lines, each having a conductor and a braid covering the conductor.

[0009] The plurality of detection lines includes a first detection line and a second detection line.

[0010] The braid is made of electrically insulating yarn, through which a conductive liquid electrically connects the conductor of the first detection line to the conductor of the second detection line, thereby detecting the liquid.

[0011] The braid of one or both of the first and second detection lines includes a first yarn and a second yarn intersecting the first yarn, wherein the second yarn is thinner than the first yarn. Brief Description of the Drawings

[0012] FIG1 is a simplified perspective view showing a leakage detection line according to one embodiment. Specification 1 / 14 pages 3 CN 121794555 A

[0013] FIG2 is a simplified diagram showing the shape of the cross-section along line II-II in FIG1.

[0014] FIG3 is a simplified diagram showing the shape of the cross-section along line III-III in FIG1. ​​Detailed Description

[0015] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0016] As shown in FIG1, the leakage detection line 100 of this embodiment includes a plurality of detection lines 10. The leakage detection line 100 of this embodiment includes a first detection line 10a and a second detection line 10b in pairs. The first detection line 10a and the second detection line 10b of this embodiment each include a conductor 11 and a braid 12 covering the conductor 11. In this embodiment, the first detection line 10a includes a first conductor 11a that becomes the first conductor 11 in the leakage detection line 100 and a first braid 12a covering the first conductor 11a, and the second detection line 10b includes a second conductor 11b that becomes the second conductor 11 in the leakage detection line 100 and a second braid 12b covering the second conductor 11b.

[0017] The first conductor 11a and the second conductor 11b are each made of conductive wire. The first braid 12a and the second braid 12b are each made of yarn, which is formed of a material having electrical insulation properties (e.g., a volume resistivity of 1 × 10⁸ Ω·cm or higher at 25°C). The leakage detection line 100 of this embodiment has the following structure: when a conductive liquid leaks from a pipe or the like, the liquid passes through the first braid 12a to reach the first conductor 11a, and the liquid flows through…The second conductor 11b is reached through the second braid 12b, thereby electrically connecting the first conductor 11a and the second conductor 11b, and significantly reducing the resistance between the two detection lines 10, which should have been electrically insulating, thereby detecting the presence of the liquid.

[0018] The leakage detection line 100 of this embodiment is not particularly limited in its application, and can be configured, for example, along a pipe connected by a flange. In addition, it can be extended in parallel with a pipe with a small diameter and many bends, such as the pipe of a water-cooled high-capacity data server, or extended in a coiled manner. The leakage detection line 100 of this embodiment, which can be configured in a narrow part due to its small radius of curvature (e.g., a radius of curvature of 10 mm or less), has a small diameter and excellent flexibility and bending performance.

[0019] The first detection line 10a and the second detection line 10b in the leakage detection line 100 are configured to be in contact with each other and extend along the length direction DL of the leakage detection line 100, and are parallel to each other in the length direction DL of the leakage detection line 100. In the leakage detection line 100 of this embodiment, an outer braid 20 is provided to bundle and cover these detection lines 10, so as to maintain the contact state between the first detection line 10a and the second detection line 10b. The outer braid 20 is configured to be a cylindrical shape that can enclose the thickness of the first detection line 10a and the second detection line 10b, and extends along the length direction DL of the leakage detection line 100.

[0020] The first detection line 10a and the second detection line 10b can be configured to be arranged only laterally, or they can be provided in a twisted state on the leakage detection line 100. Assuming that the leakage detection line 100 is bent, if the first detection line 10a and the second detection line 10b are stacked in the bending direction, the contact state between the detection lines 10 is easily maintained in a good state. On the other hand, at the bending point, the first detection line 10a and the second detection line 10b are arranged laterally. For example, if the first detection line 10a and the second detection line 10b are encountered at the midpoint of the flange of the pipe and local stress is applied to that point, the first detection line 10a and the second detection line 10b may separate, thereby reducing the detectability of the liquid. In addition, even if the bending stress is applied equally to the two laterally arranged detection lines 10, if the first braid 12a and the second braid 12b are laterally extended and their cross-sectional shape is deformed into a laterally elongated elliptical cylinder, the distance between the first conductor 11a and the second conductor 11b may be increased.

[0021] By twisting the first detection line 10a and the second detection line 10b together, accidental separation can be suppressed. For the first detection line 10a and the second detection line 10b, it is easier to maintain contact by twisting with a short pitch. From this point of view, the specification 2 / 14 pages 4 CN 121794555 AStarting from this point, the number of twists between the first detection line 10a and the second detection line 10b per unit length of the leak detection line 100 can be, for example, 15 times / m or more. The number of twists between the first detection line 10a and the second detection line 10b can also be 20 times / m or more, or 25 times / m or more. On the other hand, twisting the first detection line 10a and the second detection line 10b with a long pitch is advantageous in terms of giving the leak detection line 100 good flexibility. From this point of view, the number of twists between the first detection line 10a and the second detection line 10b per unit length of the leak detection line 100 can be, for example, 90 times / m or less. The number of twists between the first detection line 10a and the second detection line 10b can be 80 times / m or less, or 70 times / m or less.

[0022] The leak detection line 100 may also include three or more detection lines 10, including a third detection line. Furthermore, the leakage detection line 100 can also be configured to detect leakage not only based on the electrical connection between the first detection line 10a and the second detection line 10b, but also based on the electrical connection between the first detection line and the third detection line, the electrical connection between the second detection line and the third detection line, etc.

[0023] The leakage detection line 100 may also include wires other than the detection line 10. When a voltage or the like is applied between the first detection line 10a and the second detection line 10b at one end of the leakage detection line 100 to determine the electrical connection between the first detection line 10a and the second detection line 10b, the first detection line 10a and the second detection line 10b become open circuits (insulated) at the other end of the leakage detection line 100. As wires other than the detection line 10, for example, it may be an electric wire that is electrically connected to the first detection line 10a and the second detection line 10b at the other end of the leakage detection line 100. In this case, if the conductor 11 (first conductor 11a) of one of the detection lines 10 (e.g., the first detection line 10a) is made to be the same conductor as a general electrical wire (e.g., copper wire, aluminum wire, etc.), and the conductor 11 (second conductor 11b) of the other detection line 10 (e.g., the second detection line 10b) is made to be, for example, a conductor made of a material with a higher resistance value than that of a general electrical wire (hereinafter referred to as "resistance conductor"), and the above-mentioned wire is connected to the detection line having the resistance conductor, then when detecting leakage, the location of leakage can be easily determined.

[0024] The above-mentioned wire can be a wire that functions as a tensile member, or a wire that fills the gap between the outer braid 20 and the detection line 10. If the first detection line 10a and the second detection line 10b are covered with the outer braid 20 together with such a clamping material, the fastening force formed by the outer braid 20 can easily function as the abutting force between the first detection line 10a and the second detection line 10b, even with a particularly small radius of curvature (e.g.Even if the radius of curvature is less than 8 mm, bending the leakage detection line 100 can also suppress the separation of the detection lines 10 from each other (conductors 11 from each other).

[0025] The first braid 12a described above includes: a first yarn (hereinafter also referred to as "right-hand yarn"), which is wound around the first conductor 11a in a clockwise direction around the first conductor 11a when the length direction DL of the leakage detection line 100 is set as the travel direction; and a second yarn (hereinafter also referred to as "left-hand yarn"), which is wound around the first conductor 11a in a counterclockwise direction around the first conductor 11a. In the first braid 12a, the right-hand yarn and the left-hand yarn are braided in such a way that their positions on the radial direction DD of the leakage detection line 100 are interchanged in the direction of travel. The second braid 12b described above is also the same, and is braided by a right-handed yarn wound around the second conductor 11b while rotating to the right in the direction of travel, and a left-handed yarn wound around the second conductor 11b while rotating to the left.

[0026] In the detection lines 10 of the first detection line 10a and the second detection line 10b included in the leakage detection line 100, the thickness of two yarns is generated at the intersection of the right-handed yarn and the left-handed yarn constituting the braid 12. Therefore, as shown in FIG2, if the calculated outer diameter is expressed in terms of radius (hereinafter also referred to as "theoretical radius (Ri)"), it becomes the value of adding the radius of the conductor 11 and the thickness of the two yarns. If it is expressed in terms of diameter (hereinafter also referred to as "theoretical diameter (Di)"), it becomes the value of adding the diameter Dc of the conductor 11 and the thickness of the four yarns.

[0027] As described above, if the yarn constituting the braid 12 is made thinner, the thickness of the detection line 10 can be made thinner, and the leakage detection line 100 can also be made thinner. Regarding this, based on the inventor's observation regarding the construction of the leakage detection line, not all parts of the braid have a thickness of two yarns. For example, at the intermediate point between when a right-handed yarn passes over a left-handed yarn and when it passes under the next left-handed yarn, the thickness of the braid is equal to the amount of one yarn. That is, at this intermediate point, when the direction of the conductor 10 around the detection line 10 is set to the circumferential direction, the right-handed and left-handed yarns are arranged laterally in the circumferential direction, and therefore the thickness of the braid in the radial direction of the detection line 10 is equal to the amount of one yarn. Therefore, if all the yarn constituting the braid is made thinner, it is difficult to ensure the distance between the conductors. Furthermore, if the leak detection line is bent with a small radius of curvature along the flange of the piping, the gaps between adjacent yarns in the braid may widen significantly. In such locations, due to the difference in bending rigidity between the braid and the conductor, there is a concern that the conductor may fly out through the gaps. Therefore, simply thinning the yarns constituting the braid will not only prevent the conductor from slipping out, but also...The conductor is prone to flying out, and the flying-out conductor can easily invade the braid of the adjacent detection line from the outside and come into contact with the conductor of the detection line. Therefore, if the yarn is only made thinner, there is a concern that the insulation between the conductors cannot be adequately ensured and false detection may occur. In order to prevent the conductor of the detection line from being exposed, it is also possible to use fine yarn to form a braid in the form of mesh blockage, but in this case, the time for the liquid to reach the conductor through the braid becomes longer, which may also reduce the responsiveness of the leakage detection.

[0028] In this embodiment, the above-mentioned problem is solved by making the right-hand and left-hand yarns different in thickness. That is, by making one of the right-hand and left-hand yarns thinner, the theoretical diameter of the detection line 10 (Di in FIG2) can be reduced. As shown in FIG3, in the part where the right-hand and left-hand yarns are arranged laterally in the circumferential direction, the distance between the conductors 11 is maintained by the amount of the thicker side yarn (first yarns 121a, 121b). Therefore, in this embodiment, false detection of the leakage detection line 100 can be suppressed.

[0029] For the leakage detection line 100 of this embodiment, the left-handed yarn can be finer than the right-handed yarn, and the right-handed yarn can also be finer than the left-handed yarn. In the leakage detection line 100 of this embodiment, the braid 12 can be made of yarns with different diameters (thickness) only for one of the first braid 12a and the second braid 12b, or it can be made of yarns with different diameters for both. In this embodiment, in order to more reliably achieve the above-mentioned effect, the braid 12a and the second braid 12b are made of yarns with different diameters. In addition, as shown in FIG1, in the first braid 12a of this embodiment, a left-handed yarn that is finer than the right-handed yarn is used. On the other hand, in the second braid 12b, a right-handed yarn that is finer than the left-handed yarn is used. In this way, in this embodiment, the two adjacent detection lines 10 can easily bring the first yarns 121 into contact with each other, and can easily maintain a certain distance between the conductors 11.

[0030] Right-handed and left-handed yarns can be monofilament yarns, multifilament yarns, or textile yarns. Right-handed and left-handed yarns are preferably monofilament yarns or multifilament yarns. Right-handed and left-handed yarns are preferably not deformed by forces applied in the radial direction (thickness direction). In the case of monofilament yarns or multifilament yarns, twisted yarns are preferred. Monofilament yarns can be, for example, polyolefin resin monofilaments such as polyethylene resin monofilaments and polypropylene resin monofilaments; polyester resin monofilaments such as polyethylene terephthalate resin monofilaments, polybutylene terephthalate resin monofilaments, polylactic acid resin monofilaments, and polyethylene naphthalate resin monofilaments; polyamide 6 resin monofilaments, polyamide 66 resin monofilaments, polyamide 610 resin monofilaments, semi-aromatic polyamide resin monofilaments, and fully aromatic polyamide resin monofilaments; polytetrafluoroethylene resin monofilaments...Monofilament yarns include: ethylene-tetrafluoroethylene copolymer resin monofilaments, polytetrafluoroethylene-perfluoroalkyl ether copolymer resin monofilaments, tetrafluoroethylene-hexafluoropropylene copolymer resin monofilaments; polyvinylidene fluoride resin monofilaments and other fluoropolymer monofilaments; polyethersulfone resin monofilaments, polysulfone resin monofilaments, polyphenylene sulfone resin monofilaments, polyphenylene sulfide resin monofilaments, polyetherimide resin monofilaments, polyphenylene ether resin monofilaments and other super engineering plastic monofilaments; ethylene-vinyl acetate copolymer resin monofilaments; polyvinyl chloride resin monofilaments; polyurethane resin monofilaments; thermoplastic elastomer monofilaments, etc. Considering the excellent detection performance when the target is water, monofilament yarns can also be made of highly hydrophilic resins such as polyester resin monofilaments and polyamide resin monofilaments. Furthermore, in terms of improving the flame retardancy of the leak detection line 100, monofilament yarns can also be made of super engineering plastic monofilaments.

[0031] As the material for multifilament yarn, the same material as the monofilament yarn exemplified above can be used. When the multifilament yarn is a twisted yarn, it can be a weakly twisted yarn with fewer than 500 twists (500T / m) per 1m length, a medium-twist yarn with more than 500 twists (500T / m) but less than 1000 twists (1000T / m), a strongly twisted yarn with more than 1000 twists (1000T / m) but less than 2500 twists (2500T / m), or an extremely strongly twisted yarn with more than 2500 twists (2500T / m). For right-hand and left-hand yarns, one can be a monofilament yarn and the other a multifilament yarn. When one or both of the right-hand and left-hand yarns are twisted, the twisted yarn can be an S-twist yarn or a Z-twist yarn. For right-hand and left-hand yarns, one can be an S-twist yarn and the other a Z-twist yarn, or both can be S-twist yarns, or both can be Z-twist yarns.

[0032] The thickness of the thicker yarn (i.e., the first yarn, which is a right-hand yarn in the first detection line 10a and a left-hand yarn in the second detection line 10b) and the thinner yarn (which is a left-hand yarn in the first detection line 10a and a right-hand yarn in the second detection line 10b) can be appropriately changed depending on the application of the leakage detection line 100, the thickness of the first conductor 11a, the second conductor 11b, etc. However, in this embodiment, the thickness (diameter: D1) of the first yarn 121 can be any one in the range of 0.2 mm or more and 0.3 mm or less. In this embodiment, the thickness (diameter: D1) of the first yarn 121 can be 0.21 mm or more, or 0.22 mm or more. The thickness (diameter: D1) of the first yarn 121 can be less than 0.29 mm or less than 0.28 mm. In this embodiment...The thickness (diameter: D2) of the second yarn 122 can be any value within the range of 0.05 mm or more and less than 0.2 mm. In this embodiment, the thickness (diameter: D2) of the second yarn 122 can be 0.08 mm or more, or 0.10 mm or more. The thickness (diameter: D2) of the second yarn 122 can be 0.18 mm or less, or 0.17 mm or less.

[0033] The thicknesses (D1, D2) of the first yarn 121 and the second yarn 122 can be measured using a digital micrometer, and can be obtained by arithmetic averaging the values ​​obtained by measuring the thickness of one yarn at multiple randomly selected locations (e.g., 10 locations) using a digital micrometer.

[0034] The difference in thickness between the first yarn 121 and the second yarn 122 (ΔD = D1 - D2) can, for example, be 0.05 mm or more and 0.15 mm or less. The difference in thickness between the first yarn 121 and the second yarn 122 (ΔD) can be 0.06 mm or more or 0.07 mm or more. The difference in thickness between the first yarn 121 and the second yarn 122 (ΔD) can be 0.14 mm or less or 0.13 mm or less.

[0035] The ratio of the thickness of the second yarn 122 to the thickness of the first yarn 121 (D2 / D1) can, for example, be 0.30 or more and 0.80 or less. This ratio (D2 / D1) can also be 0.35 or more or 0.40 or more. This ratio (D2 / D1) can be 0.75 or less or 0.70 or less.

[0036] Each of the first knitting body 12a and the second knitting body 12b can be composed of multiple right-handed yarns and multiple left-handed yarns. The material and thickness of the right-handed yarns in the first knitting body 12a can be the same as or different from the material and thickness of the right-handed yarns in the second knitting body 12b. The material and thickness of the left-handed yarns in the first knitting body 12a can be the same as or different from the material and thickness of the left-handed yarns in the second knitting body 12b. The structure of the first knitting body 12a and the second knitting body 12b can be the same or different.

[0037] The first knitting body 12a and the second knitting body 12b can be, for example, knitted in a plain weave, twill weave, or satin weave using right-hand and left-hand yarns. In the satin weave, one of the right-hand or left-hand yarns crosses over four or more of the other yarns. Therefore, while the yarns can be in close contact where the detection line is straight, the gaps between the yarns can widen where the detection line is bent with a small radius of curvature, potentially allowing a significant exposure of the conductor. In a plain weave where the right-hand and left-hand yarns are...In this structure, each yarn of the right-hand and left-hand yarns crosses with the yarn of the other, thus preventing adjacent right-hand yarns from being arranged in close contact with each other, and adjacent left-hand yarns from being arranged in close contact with each other. Furthermore, in a plain weave structure where the right-hand and left-hand yarns form a plain weave, compared to a satin weave structure, although it is easier to reduce the softness when bending the detection thread, even in areas where the detection thread is bent with a small radius of curvature, the yarns are less likely to widen. A knitted structure with the above-described structure, woven with a twill weave of right-hand and left-hand yarns, can achieve a balance between softness and the suppression of conductor exposure. In particular, a knitted structure woven with right-hand and left-hand yarns in a 2 / 2 twill weave is suitable as the first knitted structure 12a and the second knitted structure 12b of this embodiment.

[0038] For the first braid 12a and the second braid 12b, in order to suppress the formation of gaps between the yarns to prevent the conductor 11 from being exposed, it is preferable that the number of right-handed yarns (ply) and left-handed yarns constituting a mesh is small, preferably 2 or less for each ply, and more preferably 1 for each ply.

[0039] The number of meshes (yarn tubes) formed in the section around the first conductor 11a in the first braid 12a and the number of meshes (yarn tubes) formed in the section around the second conductor 11b in the second braid 12b also varies depending on the size of the first conductor 11a and the second conductor 11b, for example, 4 or more and 20 or less. The number of yarn tubes in the first braid 12a and the second braid 12b can be 16 or less or 12 or less.

[0040] The wrapping pitch (the distance traveled during one revolution around the first conductor 11a) of the right-hand and left-hand yarns in the first detection line 10a can be, for example, 4 mm or more and 20 mm or less. The same applies to the wrapping pitch (the distance traveled during one revolution around the second conductor) of the right-hand and left-hand yarns in the second detection line 10b; for example, it can be 4 mm or more and 20 mm or less. This wrapping pitch can be 5 mm or more, 6 mm or more, or 7 mm or more. This wrapping pitch can be 18 mm or less, 16 mm or less, or 14 mm or less.

[0041] The conductor diameters (Dc) of the first conductor 11a and the second conductor 11b can be the same or different; for example, they can be 0.20 mm or more and 1.00 mm or less, respectively. The conductor diameters (Dc) of the first conductor 11a and the second conductor 11b can be 0.25 mm or more, or 0.30 mm or more. The conductor diameter (Dc) of the first conductor 11a and the second conductor 11b can be less than 0.80 mm or less than 0.60 mm.

[0042] The first conductor 11a and the second conductor 11b can also be single wires, but are preferably twisted wires.11b may be a twisted wire with a nominal cross-sectional area of ​​0.024 mm² or more and 0.5 mm² or less. The nominal cross-sectional area of ​​the first conductor 11a and the second conductor 11b may be 0.035 mm² or more or 0.05 mm² or more. The nominal cross-sectional area of ​​the first conductor 11a and the second conductor 11b may be 0.3 mm² or less, 0.2 mm² or less, or 0.15 mm² or less.

[0043] When the first conductor 11a and the second conductor 11b are twisted wires, they may be bundled conductors or concentric stranded conductors. When the first conductor 11a and the second conductor 11b are twisted wires, the stranding pitch of the bare wire located on the outermost radial side may be, for example, 3 mm or more and 50 mm or less. The stranding pitch may be 4 mm or more or 5 mm or more. The stranding pitch may be 30 mm or less, 20 mm or less, or 15 mm or less.

[0044] The first conductor 11a and the second conductor 11b are preferably made of soft copper wire. The soft copper wire may be tin-plated soft copper wire or soft copper wire without plating.

[0045] In the braid 12, the coarser first yarn 121 (in the first detection line 10a, it is a right-handed yarn) is more rigid than the finer second yarn 122 (in the first detection line 10a, it is a left-handed yarn), and has a higher resistance to twisting relative to the direction of tightening towards the coarser yarn (clockwise in the first detection line 10a). When the first conductor 11a and the second conductor 11b are twisted yarns, by making the twisting direction of the outermost bare yarn opposite to the twisting direction of the first yarn 121 (counterclockwise in the first detection line 10a), it is expected to suppress the effect of the bare yarn flying out of the braid 12 due to the twisting unraveling. On the other hand, in the braid 12, the fine second yarn 122 (which is a left-handed yarn in the first detection line 10a) has excellent following properties toward the surface of the conductor 11 compared to the coarse first yarn 121 (which is a right-handed yarn in the first detection line 10a). When the first conductor 11a and the second conductor 11b are twisted yarns, by making the twisting direction of the outermost bare yarn opposite to the twisting direction of the second yarn 122 (clockwise: Z twist in the first detection line 10a), it is expected to suppress the effect of the front end of the bare yarn that breaks off from the braid 12 in the event of a breakage.

[0046] The first braid 12a and the second braid 12b preferably cover the first conductor 11a and the second conductor 11b in a manner that satisfies the following inequality (1).

[0047] Length occupancy rate ≤ 45% … (1)

[0048] Length occupancy rate =

[0049] {(Wn1×Cn1×D1) / P1+(Wn2×Cn2×D2) / P2}×100%,

[0050] Wn1 = number of plies in the first yarn, Wn2 = number of plies in the second yarn,

[0051] Cn1 = number of yarn tubes in the first yarn, Cn2 = number of yarn tubes in the second yarn,

[0052] D1 = diameter of the first yarn (mm), D2 = diameter of the second yarn (mm),

[0053] P1 = wrapping pitch of the first yarn (thick yarn) in the length direction of the detection line (mm), P2 = wrapping pitch of the second yarn (fine yarn) in the length direction of the detection line (mm),

[0054] Furthermore, for the wrapping pitch (P1) of the first yarn 121 and the wrapping pitch (P2) of the second yarn 122, the length direction of the first detection line 10a and the second detection line 10b can be used as the direction of travel, and the length of the advance (length of the detection line) up to the time when the right-hand yarn and the left-hand yarn wrap around the conductor 11 a predetermined number of times (e.g., 10 times) can be measured, and the length can be divided by the number of wraps to obtain the result.

[0055] The length occupancy rate calculated according to the above formula can be 43% or less, 41% or less, 39% or less, 37% or less, or 35% or less. The length occupancy rate can also be 10% or more, for example. The length occupancy rate can be 12% or more, 15% or more, or 18% or more.

[0056] For the first braid 12a and the second braid 12b, the cross-sectional area occupancy rate, calculated as the area ratio of the exclusive area (π·(Di2-Dc2) / 4) of the braid 12 in the cross-section of a plane orthogonal to the length direction of the first detection line 10a and the second detection line 10b, is preferably 30% or more and 50% or less. The cross-sectional area occupancy rate can be 32% or more, 33% or more, or 34% or more. The cross-sectional area occupancy rate can also be 35% or more. The cross-sectional area occupancy rate can be 48% or less, 46% or less, or 44% or less. The cross-sectional area occupancy rate can also be less than 40%.

[0057] The cross-sectional area occupancy rate is calculated according to the following formula (2).

[0058] Cross-sectional area occupancy rate (%) = {(Σ S1 + Σ S2) / (Si - Sc)} × 100,

[0059] Σ S1: Cross-sectional area of ​​the first yarn (coarse yarn) (π·D1² / 4) × number of the first yarn (coarse yarn) in the detection line cross-section,

[0060] Σ S2: Cross-sectional area of ​​the second yarn (fine yarn) (π·D2² / 4) × number of the second yarn (fine yarn) in the detection line cross-section,

[0061] Si: Theoretical cross-sectional area of ​​the detection line (={(π×Di²) / 4}),

[0062] Di: Theoretical diameter of the detection line (= conductor diameter + diameter of the first yarn (coarse yarn) (D1) × 2 + diameter of the second yarn (fine yarn) (D2) × 2),

[0063] Sc: Conductor cross-sectional area (={(π×Dc2) / 4}),

[0064] Dc: Conductor diameter, Specification 7 / 14 page 9 CN 121794555 A

[0065] The outer braid 20 covering the first detection line 10a and the second detection line 10b can be, for example, a braid made of glass fiber yarn, basalt fiber yarn, aramid fiber yarn, polyester fiber yarn, etc.

[0066] The leakage detection line 100 of this embodiment can be used not only for the detection of water, but also for the detection of aqueous solutions, organic solvents with high conductivity, etc. As the liquid to be detected, it is preferable to be a liquid that exhibits a conductivity of 1×10-3 (μS / cm) or more at room temperature (e.g., 25°C). The conductivity of the liquid to be detected at room temperature (e.g., 25°C) can be 1×10-2 (μS / cm) or more, or 1×10-1 (μS / cm) or more, or 1 (μS / cm) or more. If we give specific names of liquids suitable for detection, for example: water; acidic solutions such as hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, and acetic acid; alkaline aqueous solutions such as ammonia and sodium hydroxide; hydrophilic organic solvents such as methanol, ethanol, acetone, propylene glycol, and ethylene glycol.

[0067] The leak detection line 100 of this embodiment is useful for leak detection in devices with limited installation space, such as water-cooled data servers, but its application is not particularly limited. It can also be used for leak detection of piping, joints, valves, etc. in general equipment, and can also be used for leak detection of heat exchangers, tanks, etc. That is, the disclosure of the leak detection line 100 in this embodiment is limiting, and the leak detection line 100 of the present invention is not limited in any way to the examples shown above.

[0068] In addition, this specification includes the following disclosures regarding the invention of the leak detection line.

[0069] [1]A leakage detection line,

[0070] The leakage detection line comprises a plurality of detection lines, the detection line comprising a conductor and a braid covering the conductor,

[0071] the plurality of detection lines includes a first detection line and a second detection line,

[0072] the braid is composed of electrically insulating yarn, and a conductive liquid passes through the braid to electrically connect the conductor of the first detection line to the conductor of the second detection line, thereby detecting the liquid, wherein,

[0073] the braid of one or both of the first detection line and the second detection line comprises a first yarn and a second yarn intersecting the first yarn, the second yarn being thinner than the first yarn.

[0074] [2] According to the leakage detection line described in [1], wherein,

[0075] the first yarn is a monofilament yarn or multifilament yarn with a diameter of 0.2 mm or more and 0.3 mm or less,

[0076] the second yarn is a monofilament yarn or multifilament yarn with a diameter of 0.05 mm or more and less than 0.2 mm.

[0077] [3] According to the leakage detection line described in [2], wherein,

[0078] The number of strands of the first yarn in the braid is 1, and the number of strands of the second yarn is 1.

[0079] [4] According to any one of [1] to [3], wherein,

[0080] the conductor is covered by the braid in such a way that one or both of the first detection line and the second detection line satisfy the following inequality (1).

[0081] Length occupancy rate ≤ 45% … (1)

[0082] Length occupancy rate =

[0083] {(Wn1×Cn1×D1) / P1+(Wn2×Cn2×D2) / P2}×100%,

[0084] Wn1 = number of plies of the first yarn, Wn2 = number of plies of the second yarn,

[0085] Cn1 = number of yarn tubes of the first yarn, Cn2 = number of yarn tubes of the second yarn,

[0086] D1 = diameter of the first yarn (mm), D2 = diameter of the second yarn (mm),

[0087] P1 = wrapping pitch of the first yarn in the length direction of the detection line (mm), P2 = wrapping pitch of the second yarn in the length direction of the detection line (mm)

[0088] Examples

[0089] The present invention will be further described in detail by way of examples, but the present invention is not limited to these examples. Instruction manual, page 8 / 14, 10 CN 121794555 A

[0090] (Comparative Example 1 (Conventional Example))

[0091] As shown in Table 1, a leakage detection line of Comparative Example 1 (Conventional Example) was manufactured by braiding basalt yarn in a bundled manner with the first detection line and the second detection line.

[0092] The first detection line and the second detection line have the same structure.

[0093] Each conductor uses a twisted wire (twisting pitch 6 mm) made by twisting 7 tinned soft copper wires with a thickness of 0.127 mm.

[0094] The conductor is braided with monofilament yarn with a thickness of 0.25 mm.

[0095] The braided body is made with 1 right-hand twisted yarn and 4 left-hand twisted yarns, and the wrapping pitch of each yarn is 10 mm.

[0096] The thickness (theoretical diameter) of the leakage detection line in Comparative Example 1 is 1.76 mm. The length occupancy rate and cross-sectional area occupancy rate were calculated using the following formulas, and the results were 20.0% (length occupancy rate) and 19.8% (cross-sectional area occupancy rate), respectively.

[0097] · Length occupancy rate = {(number of right-hand yarn strands 1 × number of right-hand yarn tubes 4 × diameter of right-hand yarn 0.25) / pitch 10 + (number of left-hand yarn strands 1 × number of left-hand yarn tubes 4 × diameter of left-hand yarn 0.25) / pitch 10} × 100 (%),

[0098] · Cross-sectional area occupancy rate = {cross-sectional area of ​​right-hand yarn (π·0.252 / 4) × number of right-hand yarn tubes 4 + cross-sectional area of ​​left-hand yarn tubes 4 + cross-sectional area of ​​left-hand yarn tubes 4 + cross-sectional area of ​​right ...=Cross-sectional area of ​​the line (π·0.252 / 4) × number of left-handed yarn tubes 4} / [theoretical cross-sectional area of ​​the detection line {π×(conductor diameter 0.76 + right-handed yarn diameter 0.25×2 + left-handed yarn diameter 0.25×2)2 / 4} - conductor cross-sectional area (π× conductor diameter 0.762 / 4)] × 100 (%),

[0099] (Evaluation)

[0100] The detection performance, flexibility, and ease of recovery after leakage detection of the leakage detection line of Comparative Example 1 were evaluated.

[0101] The specific evaluation method is as follows. In addition, the evaluation results are shown in Table 1.

[0102] (Detectability)

[0103] The leakage detection line was held in a manner that was approximately horizontal in the air, and water with a conductivity of 100.0 μS / cm was dripped from a position 1 cm directly above it at approximately constant intervals. The water was dripped at a rate of 0.6 ml per minute. Then, the number of drops until the resistance between the detection lines became below 100kΩ was measured. Ten leakage detection lines were tested, and the average number of drops was calculated.

[0104] (Bendability)

[0105] Six leakage detection lines were used as test samples. Each leakage detection line was bent at 180° and subjected to 100 bending stretches. After this bending stretch, two detection lines were taken out for observation. The number of conductors flying out of the braid was measured, and the total number of the 12 detection lines was calculated.

[0106] (Recovery (Removal))

[0107] The detection capability was evaluated by wiping away the moisture from the leakage detection lines where the resistance between the detection lines became below 100kΩ, and confirming whether the resistance value recovered due to the removal of moisture. If the recovery of the resistance value was observed, it was evaluated as "0"; if no recovery was observed, it was evaluated as "×".

[0108] (Comparative Examples 2-4)

[0109] Except for setting up a braid with the thickness of the right-hand and left-hand yarns reduced from 0.25 mm to 0.15 mm and the loop pitch as shown in Table 1, the leakage detection line was made in the same manner as in Comparative Example 1, and the same evaluation was performed as in Comparative Example 1. The evaluation results are shown in Table 1.

[0110] As can be seen from the results in Table 1, if only the yarn constituting the braid is made thinner, the conductor is prone to flying out, which may lead to false detection.

[0111] (Comparative Examples 5-8)

[0112] Except that the thickness of the right-hand and left-hand yarns was reduced from 0.25 mm to 0.15 mm, and the number of yarn tubes of the right-hand and left-hand yarns was increased from 4 to 8, and a braid with the loop pitch shown in Table 1 was formed, the leakage detection line was manufactured in the same manner as in Comparative Example 1, and the same evaluation was performed as in Comparative Example 1. The evaluation results are shown in Table 1.

[0113] As can be seen from the results in Table 1, conductor ejection can be suppressed to some extent by making the yarn constituting the braid thinner and increasing the number of yarn tubes, but it is difficult to sufficiently suppress conductor ejection when the number of yarn tubes is doubled.

[0114] (Comparative Examples 9 to 11)

[0115] Except for reducing the thickness of the right-hand and left-hand yarns from 0.25 mm to 0.15 mm, increasing the number of yarn tubes of the right-hand and left-hand yarns from 4 to 12, and making a braid with the loop pitch shown in Table 1, the leakage detection line was made in the same manner as in Comparative Example 1, and the same evaluation was performed as in Comparative Example 1. The evaluation results are shown in Table 1.

[0116] As can be seen from the results in Table 1, by setting the number of yarn tubes to 3 times that of Comparative Examples 1 to 4 as in Comparative Examples 9 to 11, conductor ejection can be further suppressed compared to Comparative Examples 5 to 8 where the number of yarn tubes is set to 2 times. Furthermore, as can be seen from the results in Table 1, by setting the number of yarn tubes to 3 times, the detection performance is significantly reduced.

[0117] (Examples 1-3)

[0118] Except for setting the thickness of the left-hand yarn in the right-hand yarn and left-hand yarn to be reduced from 0.25 mm to 0.15 mm, and increasing the number of yarn tubes of the right-hand yarn and left-hand yarn from 4 to 12, and making it into a braid with the loop pitch as shown in Table 2, the leakage detection line was made in the same manner as in Comparative Example 1, and the same evaluation was performed as in Comparative Example 1. The evaluation results are shown in Table 2.

[0119] As can be seen from the results in Table 2, by making one of the yarns thinner, the detection performance is slightly worse than in Comparative Example 1, but the conductor flyout is greatly improved, and both detection performance and false detection suppression can be achieved.

[0120] (Examples 4-6, Comparative Examples 12-14)

[0121] Leakage detection lines were manufactured by simply arranging them laterally within an outer braid without twisting the first and second detection lines together, and the same evaluation was performed as before. The results are shown in Table 3.

[0122] As can be seen from Table 3, by making the yarn thickness different, the same effect as shown in Table 2 is achieved even without twisting the first and second detection lines together.

[0123] Furthermore, as can be seen from the results in Tables 1-3, adjusting the length occupancy rate and cross-sectional area occupancy rate to predetermined values ​​is advantageous in terms of significantly improving the effect.

[0124] [Table 1] Specification 10 / 14 pages 12 CN 121794555 A

[0125]

[0126] [Table 2] Specification 11 / 14 pages 13 CN 121794555 A

[0127]

[0128] [Table 3] Specification 12 / 14 pages 14 CN 121794555 A

[0129]

[0130] As can be seen from the above, according to the present invention, it is possible to provide a solution that can significantly reduce the detectability of leakage.Leakage detection lines that suppress false detections. Reference numerals

[0131] 10…detection line (10a…first detection line, 10b…second detection line); 11…conductor (11a…first conductor, 11b…second conductor); 12…braid (12a…first braid, 12b…second braid); 121…first yarn; 122…second yarn; 20…outer braid; 100…leakage detection line; DD…(radial direction of the leakage detection line); DL…(length direction of the leakage detection line). Instruction sheet 14 / 14 Page 16 CN 121794555 A Figure 1 Figure 2 Instruction drawing 1 / 2 Page 17 CN 121794555 A Figure 3 Instruction sheet drawing 2 / 2 Page 18 CN 121794555 A The subject of the present invention is that providing a liquid leak detecting line capable of suppressing erroneous detection while suppressing a significant decrease in liquid leak detection performance. In order to resolve the above mentioned subject, a liquid leak detecting line comprising a plurality of detecting lines is provided, the detecting line comprises a conductor and a braided body covering the conductor, the plurality of the detecting lines include a first detecting line and a second detecting line, the braided body is configured from an electrically insulating yarn, and an electrically conductive liquid electrically connects the conductor of the firstdetecting line and the conductor of the second detecting line through the braided bodies, and thus the liquid is detected, wherein the braided body of one or both of the first detecting line and the second detecting line comprises a first yarn and a second yarn intersecting the first yarn, and the second yarn is thinner than the first yarn. Abstract

Claims

1. A leakage detection line, The leakage detection line has multiple detection lines, and the detection line has a conductor and a braid covering the conductor. The plurality of detection lines include a first detection line and a second detection line. The braided structure is made of electrically insulating yarn. A conductive liquid passes through this braided structure, electrically connecting the conductors of the first detection line and the second detection line, thereby detecting the liquid. Its features are, The braid of one or both of the first detection line and the second detection line has a first yarn and a second yarn that intersects with the first yarn, the second yarn being thinner than the first yarn.

2. The leakage detection line according to claim 1, characterized in that, The first yarn is a monofilament yarn or multifilament yarn with a diameter of 0.2 mm or more and 0.3 mm or less. The second yarn is a monofilament yarn or multifilament yarn with a diameter of 0.05 mm or more and less than 0.2 mm.

3. The leakage detection line according to claim 2, characterized in that, The first yarn in the braid has 1 ply, and the second yarn has 1 ply.

4. The leakage detection line according to any one of claims 1 to 3, characterized in that, The conductor is covered by the braid in such a manner that one or both of the first detection line and the second detection line satisfy the following inequality (1). Length occupancy ≤ 45% … (1) Length occupancy rate = {(Wn1×Cn1×D1) / P1+(Wn2×Cn2×D2) / P2}×100%, Wn1 = number of plies in the first yarn, Wn2 = number of plies in the second yarn Cn1 = Number of yarn bobbins in the first yarn, Cn2 = Number of yarn bobbins in the second yarn D1 = Diameter of the first yarn (mm), D2 = Diameter of the second yarn (mm). P1 = the wrapping pitch of the first yarn along the length of the detection line (mm), P2 = the wrapping pitch of the second yarn along the length of the detection line (mm).

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