Background technology
System is the critical facility that guarantees power equipment safety reliability service power ground.The earth electrode of existing power equipment mainly has the following disadvantages: (1) resistance to corrosion is poor.Common metal earth electrode is estimated 20 years useful life, the even i.e. seriously corrosion in 3~5 years having.(2) cost is high.The high domestic application rate of copper earthing material cost is low, galvanized steel have certain antiseptic effect, but price is also far above common iron.(3) not high with soil bonding tightness.Metal earth electrode is due to the hard fragility feature of itself, is combined defective tightness in laid processes with soil, and contact resistance forms greatly and easily the electrochemical corrosion of oxygen concentration difference.(4) inconvenience transportation and construction.Metal earthing material Heavy Weight, the large inconvenience transportation of volume and construction.(5) metal material subjects to theft destruction.Due to metal material secondary, peddle and be worth highly, ground lead, ground connection box, earth electrode etc. suffer artificial theft, destruction repeatly.
Graphite material electric conductivity is excellent, has good plasticity and stability, is again good resistant material simultaneously, abundant China's reserves.Graphite material is widely used in the industrial circles such as smelting, battery.In Grounding Technology of Modern Power System field, cuboid and tubular graphite grounding module and graphite resistance reducing agent have become a kind of grounding reconstruction material.The Chinese patent < < thunder-preventing graphite grounding device of notification number CN1042077C and making thereof and construction method > >, the Chinese patent < < anti-corrosion grounding module > > of notification number CN201478468U, Chinese patent < < graphite grounding module > > of publication No. CN102496790A, the Chinese patent < < anti-thunderstrock grounding device of composite carbon material of publication number CN1110013A and manufacture method > > thereof, the manufacture method > > of the Chinese patent < < low resistance earthing module material of notification number CN1047881C, the Chinese patent < < metal-graphite carthing body > > of notification number CN2454912Y, the Chinese patent < < grounding conductive concrete > > of notification number CN1194930C, the Chinese patent < < ground mould with physical resistance reducing agent > > of notification number CN2845202Y, the Chinese patent < < integrated connection formula expandable graphite nonmetal grounding device > > of notification number CN2733631Y, the patents such as the Chinese patent < < non-corrosive assembled grounding electrode of notification number CN101030458B and resistance-lowering material and production method > > thereof have been recorded square or cylindrical graphite have been connected with metal, imbed and undergroundly can realize corrosion resistant ground connection.
Graphite also has application in electric power system ground connection as resistance reducing agent material, the Chinese patent < < long-effective corrosion-prevention physical resistance-reducing agent > > of notification number CN101752021B, Chinese patent < < long service life, corrosion-proof, and electric resistance reducing agent for earthing (modified model) the > > of notification number CN100498978C, Chinese patent < < resistance reducing agent > > of notification number CN100490020C, the Chinese patent < < solid grounded resistance reducing agent of notification number CN1249730C and preparation method thereof > > etc. has recorded the graphite resistance reducing agent for grounding reconstruction.
Graphite grounding module is due to problems such as production cost is high, fragility easy fracture, installation inconvenience, and actual popularization faces some difficulties; Graphite resistance reducing agent is still subject to certain limitation because its poor stability, resistance reducing effect shortcoming limited, that easily cause the aspects such as metal earth electrode burn into contaminated soil make its application.
Utility model content
The problem existing for existing electric power system lightning-proof grounding body, the utility model provide a kind of corrosion-resistant, conductivity is good, pliability good, the compound earthing material of novel graphite with low cost.
For solving the problems of the technologies described above, the utility model adopts following technical scheme:
The compound earthing material of novel graphite, its outward appearance is rope form or twisted wire shape, comprises the composite stone line of ink marker braid of composite stone line of ink marker inner core and composite stone line of ink marker inner core outside parcel, wherein:
Composite stone line of ink marker inner core is many composite graphite wire harness or the single first composite stone lines of ink marker that the first composite stone line of ink marker forms, the first composite stone line of ink marker is obtained through twisting by the first composite stone ink ribbon, and the first described composite stone ink ribbon comprises upper and lower worm graphite linings and the fibrous skeleton between upper and lower worm graphite linings;
Composite stone line of ink marker braid is obtained by the second composite stone line of ink marker braiding, the second composite stone line of ink marker is obtained through twisting by the second composite stone ink ribbon, and the second described composite stone ink ribbon comprises upper and lower worm graphite linings and the fibrous skeleton between upper and lower worm graphite linings.
The fibrous skeleton between upper and lower worm graphite linings of the first composite stone ink ribbon and the second composite stone ink ribbon mainly plays " skeleton " supporting role, and the described fibrous skeleton between upper and lower worm graphite linings is one or more in organic fiber, inorfil and metallic fiber.The fibrous skeleton between upper and lower worm graphite linings of the first composite stone ink ribbon and the second composite stone ink ribbon can be identical or different.
For strengthening the conductivity of composite stone line of ink marker inner core, a kind of preferred version is: the fibrous skeleton between upper and lower worm graphite linings of the first composite stone ink ribbon at least comprises conductive fiber, described conductive fiber is one or more in metallic fiber, alloy fiber and conductive carbon fibre, and conductive fiber accounts for the ratio of fibrous skeleton depending on actual fabrication cost.If conductive fiber is conductive carbon fibre, in the first composite stone ink ribbon, conductive carbon fibre preferred amount is no more than 2.
For strengthening the mechanical property of composite stone line of ink marker braid, a kind of preferred version is: the fibrous skeleton between upper and lower worm graphite linings of the second composite stone ink ribbon at least comprises toughened fiber, described toughened fiber is preferably one or more in Kafra fiber, carbon fiber and nickel fiber, and toughened fiber accounts for the ratio of fibrous skeleton depending on actual fabrication cost.In the second composite stone ink ribbon, toughened fiber preferred amount is to be no more than 1/3 of fibrous skeleton quantity.
Above-mentioned composite stone line of ink marker inner core consists of 1 ~ 120 sub-thread, the first composite stone line of ink marker, and sub-thread the first composite stone line of ink marker quantity that composite stone line of ink marker inner core adopts is determined according to the compound earthing material diameter of needed graphite.
Above-mentioned composite stone line of ink marker braid consists of the second composite stone line of ink marker braiding of 12 ~ 64 sub-threads.
The fibrous skeleton outer surface between upper and lower worm graphite linings of above-mentioned the first composite stone ink ribbon and the second composite stone ink ribbon is coated with adhesive phase.
The compound earthing material of the utility model graphite adopts nonmetal manufacture, has solved the etching problem that existing metal earthing material exists; The characteristic of major diameter, flexible can increase the contact area with soil, reduces earth resistance.In addition, convenient transportation, construction are not subject to landform restriction, cost advantage low, that prevent the aspects such as artificial pilferage that the applicable large-scale production of the compound earthing material of the utility model graphite is manufactured, and social benefit is obvious.
Composite stone line of ink marker inner core consists of the first composite stone line of ink marker of linear array, with respect to composite stone line of ink marker braid, material application is few, and current lead-through path is short, that wire harness straight line is arranged is long-pending large with soil contact, compactness is high, conductivity that can the compound earthing material of Integral lifting graphite.The first composite stone line of ink marker can be selected composite conducting fiber by demand.
Outer field composite stone line of ink marker braid mainly plays global formation and electric action, can select as required composite toughening fiber further to improve the mechanical property of the second composite stone line of ink marker, thereby improves mechanical strength and the conductance of graphite composite material integral body.According to described, the weaving manner that outer composite stone line of ink marker braid can adopt multilayer cover to compile, the method can greatly improve the compactness of composite graphite earthing material.In addition, while carrying out multilayer cover volume, each braid adopts graphite line quantity to increase progressively successively from inside to outside, and its manufacturing cost is completely controlled.
Compared to the prior art, the utlity model has following distinguishing feature:
1, the compound earthing material of the utility model graphite have that corrosion-resistant, electric conductivity is good, flexible, cheap, easy transportation, the accurate advantages of higher of being combined with soil; Due to cheap, also can avoid artificial theft to destroy.
2, the utility model is for electric power system Lightning protection field provides a practicable approach, and all need the engineering field of electrical grounding to be used in transformer station, overhead power transmission line pole tower, elevation building etc.
Embodiment
Fig. 2 is shown in a kind of concrete enforcement of the compound earthing material of novel graphite that the utility model provides, and comprises double-layer structure, the composite stone line of ink marker inner core (5) of internal layer for being formed by the first composite graphite wire harness, and skin is composite stone line of ink marker braid (4).
Below in conjunction with embodiment and accompanying drawing, describe the preparation method of the compound earthing material of the utility model graphite in detail.
1, preparation worm graphite.
Worm graphite can directly be bought, and also can prepare voluntarily.This concrete enforcement be take crystalline flake graphite as raw material, prepares voluntarily worm graphite, is specially:
(1) prepare expansible graphite:
Adopt sulfuric acid or nitric acid acidifying crystalline flake graphite, employing strong oxidizer (as, KMnO
4, KClO
4or H
2o
2) oxidation crystalline flake graphite, can obtain expansible graphite;
(2) prepare worm graphite:
By expansible graphite expanded 5 ~ 6s at 850 ~ 950 ℃ of temperature, obtain worm graphite.
2, preparation the first composite stone ink ribbon and the second composite stone ink ribbon.
(1) adopt rolling equipment to be depressed into less and to be pressed into worm graphite paper 2 times myrmekite ink roller, individual layer worm graphite paper thickness is greater than 0.1mm, arranges and soaked fibrous skeleton (2) the acquisition composite graphite paper of adhesive between two-layer worm graphite paper (1,3).
It is upper that fibrous skeleton (2) uniform spreading that one or more were soaked to adhesive is located at lower floor's worm graphite paper (3), carries out the thermosetting of 10 ~ 40s and process at 110 ~ 300 ℃ of temperature, afterwards, lays upper strata worm graphite paper (1).Adopt rolling equipment to make composite graphite paper through at least twice roll-in, composite graphite paper thickness is greater than 0.2mm.Composite graphite paper bag is drawn together the first composite graphite paper and the second composite graphite paper, and the fibrous skeleton of laying in the first composite graphite paper and the second composite graphite paper can be the same or different.
As a kind of preferred version, between the two-layer worm graphite paper of the first composite graphite paper, at least comprise conductive fiber, conductive fiber can be one or more in metallic fiber, alloy fiber and conductive carbon fibre.Between the two-layer worm graphite paper of the second composite stone ink ribbon, at least comprise toughened fiber.
Above-mentioned adhesive can be thermosetting polymer glue or conducting resinl, wherein, thermosetting polymer glue can-formaldehyde resin adhesive stupid for acrylic size, polyurethane/PU glue, amino resin adhesive, phenolic resin glue, epoxide-resin glue, furane resins glue, resorcin-formaldehyde resin adhesive, diformazan, unsaturated polyester ester gum, composite resin glue, polyimides glue or urea-formaldehyde resin adhesive etc.; Conducting resinl can be cupric powder conductive adhesive, nickel powder conducting resinl, plating macromolecular compound conducting resinl, carbon black conducting resin, chopped carbon fiber conducting resinl or graphite conductive adhesive.
Above-mentioned fibrous skeleton can be organic fiber (for example: polyester fiber/terylene, Fypro/polyamide fibre or nylon, vinal/polyvinyl, polyacrylonitrile fibre/acrylic fibers, polypropylene fibre/polypropylene fibre or polyvinyl chloride fibre/polyvinyl chloride fibre), inorfil (for example, glass fibre, carbon fiber, boron fibre, kevlar fiber or ceramic fibre), metallic fiber (for example: copper wire, nickel wire or stainless steel wire).Being layed in fibrous skeleton between two-layer worm graphite paper can be thread, wire or band shape.
(2) cutting the first composite graphite paper and the second composite graphite paper obtain the first composite stone ink ribbon and the second composite stone ink ribbon.
Along fibrous skeleton, longitudinally cut respectively the first composite graphite paper and the second composite graphite paper obtains the first composite stone ink ribbon and the second composite stone ink ribbon, see Fig. 1.The first composite stone ink ribbon and the second composite graphite bandwidth are 10mm ~ 40mm.
Toughened fiber in the second composite stone ink ribbon is preferably the 600D model Kafra fiber of E.I.Du Pont Company, and 600D Kafra fiber can make the tension load of the sub-thread second composite stone line of ink marker promote more than 2 times, can compound 1 ~ 3 Kafra fiber in the second composite stone ink ribbon.Conductive fiber conductivity in the first composite stone ink ribbon should be greater than 1 * 10
-3Ω cm, can select conductive carbon fibre, alloy fiber and erosion-resisting metallic fiber, preferably copper wire, stainless steel wire or nickel wire.Can compound 1 ~ 3 metallic fiber and/or alloy fiber in the first composite stone ink ribbon, or 1 ~ 2 conductive carbon fibre.
Because outer composite stone line of ink marker braid is high to mechanical property requirements, so can be chosen in the second composite stone ink ribbon, add toughened fiber to strengthen its mechanical property.Because composite stone line of ink marker inner core is more focused on electric conductivity, so can be chosen in the first composite stone ink ribbon, add conductive fiber to strengthen conductivity.
3, respectively the first composite stone ink ribbon and the second composite graphite band are carried out to the twisting acquisition sub-thread first composite stone line of ink marker and the sub-thread second composite stone line of ink marker.
Adopt twisting machine to carry out unidirectional twist system to composite graphite band and obtain sub-thread graphite line, gained sub-thread graphite line diameter 2 ~ 4mm, twisting machine rotating speed is preferably 60 ~ 80r/m.It is 5 ~ 50N that sub-thread the second composite graphite line tension requires.
4, adopt braiding machine at composite stone line of ink marker inner core outside braiding composite stone line of ink marker braid.
Take the first composite stone line of ink marker as composite stone line of ink marker inner core, adopt braiding machine that the sub-thread second composite stone line of ink marker is knitted to composite stone line of ink marker inner core outside and obtain at least one deck composite graphite line braid, braiding speed is 200 ~ 700mm/min.The weaving manner of composite stone line of ink marker braid can adopt single track braiding, double track braiding or many rails weaving manner; Also can adopt cover volume mode to weave MULTILAYER COMPOSITE graphite line braid.
5, reprocessing.
Adopt the connector lug and the graphite that in the compound earthing material braiding of trimmer finishing graphite process, produce to come off, for preventing that the compound earthing material of graphite from damaging, shaping diameter compression ratio should be controlled at more than 85%.
According to engineering design demand, choose the compound earthing material of graphite and the gold utensil joint of preseting length, adopt buckle machine by the compound earthing material crimping of the graphite of gold utensil joint and certain length, see Fig. 3, crimping process will remain a constant speed, and the diameter compression ratio of the compound earthing material of graphite is advisable with 60% ~ 75%.
Below will be by embodiment, and by reference to the accompanying drawings, further illustrate the utility model.
Embodiment 1
Composite graphite bandwidth 20mm, thick 0.22mm, obtain single composite graphite line through twisting, single composite graphite line tension force 9N.In this composite stone ink ribbon, be compounded with 13 impregnated glass fibres in water soluble acrylic resin.Take 48 these composite stone lines of ink marker as composite stone line of ink marker inner core, adopt braiding machine that 24 these composite stone lines of ink marker are knitted to composite stone line of ink marker inner core outside and obtain composite stone line of ink marker braid, adopt double track interlacing mode to obtain the compound earthing material of graphite of diameter 24mm.
Embodiment 2
The first composite stone ink ribbon is compounded with 13 glass fibres, and the second composite stone ink ribbon is compounded with 12 glass fibres and 1 600D Kafra fiber, and sub-thread the second composite graphite line tension is 15N.Take 48 first composite stone lines of ink marker as composite stone line of ink marker inner core, with 24 the second composite stone line of ink marker woven outer layer composite stone line of ink marker braids, adopt double track interlacing mode to obtain the compound earthing material of graphite of diameter 23.5mm.
Embodiment 3
The first composite stone ink ribbon is compounded with 11 glass fibres and 2 nickel fibers, and the second composite stone ink ribbon is compounded with 12 glass fibres and 1 600D Kafra fiber, and sub-thread the second composite graphite line tension is 15N.Take 56 first composite stone lines of ink marker as composite stone line of ink marker inner core, with 24 the second composite stone line of ink marker woven outer layer composite stone line of ink marker braids, adopt double track interlacing mode to obtain the compound earthing material of graphite of diameter 27mm.
Embodiment 4
The first composite stone ink ribbon is compounded with 13 glass fibres, and the second composite stone ink ribbon is compounded with 12 glass fibres and 1 600D Kafra fiber, and sub-thread the second composite graphite line tension is 15N.Take 32 first composite stone lines of ink marker as composite stone line of ink marker inner core, with 24 the second composite stone line of ink marker woven outer layer composite stone line of ink marker braids, adopt double track interlacing mode to obtain the compound earthing material of graphite of diameter 26mm.
The compound earthing material resistivity of graphite that embodiment 1 ~ 4 makes is all less than 2.6 * 10
-5Ω m.By < < GB/T 21698-2008 bonded earth electrode technical conditions > >, the compound earthing material of embodiment 1 ~ 4 graphite is carried out to impulse current resistance test, during test, impulse current amplitude is up to 235kA, the structure of graphite material and outward appearance are all unchanged, resistivity is floated in 2%, meets < < GB/T 21698-2008 bonded earth electrode technical conditions > > standard.
By digging in-situ ground connection ditch and bury the compound earthing material of graphite of embodiment 1 ~ 4 underground, simulate actual transmission line tower grounding network, in soil resistivity 55 Ω m areas, small-sized tower grounding net is set, ground network is 3 meters of 3 * 3m square and 45 ° of direction extensions of 4 corner levels, the about 0.6m of the whole depth of burying, power frequency earthing resistance value approximately 1.87 Ω are (along with the prolongation of the depth of burying and earth mat perimetric length, grounding resistance can further reduce), reach soil resistivity in the overvoltage protection of power industry < < DL/T 620-1997 alternating-current electric device and insulation coordination > > and be less than the standard-required that 100 Ω m area pole tower ground resistances are less than 10 Ω.
Above embodiment shows, the graphite earthing material that adopts the utility model to make has good conductivity, corrosion resistance, pliability and ductility, good with the binding ability of soil, convenient transportation and site operation, it is a kind of novel non-metal grounding material, being applicable to transformer station, transmission line bar and building etc. needs the occasion of electrical grounding, and cost is low, energy-conserving and environment-protective, lay simple and flexible, and social economic effect is remarkable.
Described in above-described embodiment, be to illustrate this patent; though describe by specific term in literary composition; but can not limit with this protection range of this patent; the personage who is familiar with this technical field can change or revise it and reach equivalent object after understanding the spirit of this patent and principle; and this equivalence change and modification all should be covered by claim scope and define in category.