RU217419U1 - Heat-resistant winding wire for power plants - Google Patents

Abstract

The utility model relates to the field of electrical engineering, in particular to the designs of heat-resistant winding wires. The technical result is to increase the reliability of the wire when exposed to high temperatures. It is achieved by the fact that the heat-resistant winding wire of power plants contains a conductive core insulated with layers of insulation layer by layer and superficially impregnated with an electrical insulating composition, while the conductive core is made in a sheath of austenitic steel, and the insulation is made in the form of a braid of quartz filaments. 1 ill.

Description

The utility model relates to the design of heat-resistant winding wires intended for use as part of impregnated or compounded windings of electrical machines (MHD equipment), control equipment for nuclear power plants and other equipment operated at high temperatures, for example, in nuclear power plants.

The operation of electrical equipment, such as electromagnetic pumps, in nuclear reactors and power plants is associated with prolonged exposure to temperatures in the range of 400-650 ° C, which, in turn, leads to heating of the equipment winding and materials of its components. In this regard, the choice of materials that are resistant to prolonged exposure to high temperatures and do not deteriorate their properties during operation is paramount in the task of developing the design of winding wires.

In the technology of manufacturing winding wires, methods are known for applying insulation with a winding and a braid (Privezentsev VA, Peshkov IB Winding and mounting wires. M .: Energy, 1971. - 552 p.). The technology of applying insulation with a winding is characterized by lower technological costs, while applying with a braid is more laborious. Nevertheless, wires with braided insulation are characterized by greater mechanical strength, which is an important advantage in their further technological processing - the manufacture of winding coils, installation, etc.

It is known from the prior art that inorganic fibers glued and impregnated with heat-resistant compounds are used as insulation for heat-resistant winding wires (Asnovich E.Z., Kolganova V.A. Highly heat-resistant electrical insulation. - M .: Energoatomizdat, 1988).

High-temperature-resistant wires from 81СSET (Italy), AnHui TianKang (Group) Shares Co. are known from the prior art. (China), the conductive core of which is made of copper plated with nickel or pure nickel, and the insulation is a layer-by-layer applied glass mica tape and a braid made of fiberglass. Such insulation provides resistance to high temperatures and fire, but has a significant thickness of the insulation, which reduces the fill factor of the motor slot, which consequently affects its performance. In addition, glass mica tape is made on a glass mesh or fiberglass substrate, usually made of type E glass (59-60% SiO ₂ ), the strength of which after exposure to a temperature of 450 ° C is reduced by 34% compared to the initial state (Jenkins PG, Yang L, Liggat JJ, Thomason JL (2015) Investigation of the strength loss of glass fiber after thermal conditioning J Mater Sci 50:1050-1057 doi: 10.1007/s10853-014-8661-x; Lund MD, Yue Y ( 2010) Impact of Drawing Stress on the Tensile Strength of Oxide Glass Fibers J Am Ceram Soc 93:3236-3243 doi: 10.1111/j.1551-2916.2010.03879.x). In addition, since the mica component of the mica tape is applied to the glass substrate using adhesive compositions based on organosilicon and phosphate-containing binders, in which destruction processes occur when exposed to temperatures (in organosilicon lacquer at temperatures above 200 ° C, combustion processes of the organic component - solvents based on xylene, toluene; phosphate binders undergo dehydration processes) (Study of the thermal stability of electrical insulating materials of electrical machines under high-temperature exposure. Vitkovsky I.V., Komov K.A., Federyaeva BC et al. // Perspective materials. 2017. No. 8 p. 21 -29), leading to delamination of the mica component from the glass substrate, local delaminations, porosity can cause insulation breakdown, which reduces the life of the product, reduces reliability indicators.

Known taken as a prototype winding heat-resistant wire (Utility Model Certificate of the Russian Federation No. surface impregnated with an organosilicate composition and varnished with an organosilicon varnish.

The disadvantage of this wire is that when exposed to high temperatures of 400-650°C, the insulation of the wire, made of high-modulus fiberglass, having a deformation onset temperature of 670°C, is destroyed, the surface of the conductive core is exposed, the galvanically deposited iron-nickel layers and the base material of the conductor are destroyed, and also diffusion penetration of products of destruction of electrical insulating coatings into metal and destruction of the metal-insulation contact surface (Asnovich E.Z., Kolganova V.A. High heat-resistant electrical insulation. - M .: Energoatomizdat, 1988), which ultimately leads to a significant decrease in its electrophysical indicators and resource of both the winding wire and the product as a whole.

The technical result of the utility model is to increase the reliability of the wire when exposed to high temperatures of 400-650°C by using heat-resistant materials used in the construction of the wire.

The claimed technical result is achieved due to the fact that in the heat-resistant winding wire of power plants, containing a conductive core insulated with layers of insulation layer by layer and surface impregnated with an electrical insulating composition, the conductive core is made with a protective sheath made of austenitic steel, and the insulation is made in the form of a braid of quartz filaments .

Indeed, the combination of these features will improve the reliability of the wire during high-temperature operation, since the presence of a sheath made of austenitic steel (for example, 12X18H10T) will protect the copper core or core of chromium-niobium bronze from the formation of Cu ₂ O, CuO, Cu ₂ O oxides and destruction of the contact surface of the metal -insulation due to diffusion penetration of degradation products {Asnovich E.Z., Kolganova V.A. High heat-resistant electrical insulation. - M.: Energoatomizdat, 1988). Quartz fiber contains more than 99% SiO ₂ , its long-term operating temperature is up to 1200 ° C (Privezentsev V.A., Peshkov I.B. Winding and mounting wires. M .: Energia, 1971. - 552 p.), therefore, the manufacture insulation made of quartz fiber will prevent the destruction of the insulation and increase its electrical insulating properties at high temperatures.

In confirmation of the above, the table shows experimental studies of the wire (PM) according to the present technical solution after exposure to temperatures of 450 and 650 ° C for 200 h and 1000 h, respectively, and also shows the characteristics of the compared wire POZH-700 with the same geometric parameters. The wire is a copper conductive core, made in a sheath of 12X18H10T steel, the insulation is made in the form of a two-layer braid of quartz filaments, layer-by-layer impregnated and glued to the core with an organosilicate composition.

It should be noted that this example shows one of the possible embodiments for the manufacture of a wire according to the claimed utility model. Since another heat-resistant composition can be chosen as an electrical insulating composition, including those from inorganic components.

From the data presented in table 1 it can be seen that the wire insulation according to the claimed technical solution (PM) has the best dielectric properties at high temperatures up to 650°C, which confirms the claimed technical result.

In FIG. an example of the design of the winding wire of heat-resistant power plants is given, which clearly demonstrates the possibility of achieving the claimed technical result. The heat-resistant winding wire of power plants is formed by a copper conductive core 1, having a sheath 2 made of steel grade 12X18H10T, to which the first insulation layer 4, made of quartz filaments in the form of a braid, is glued with an electrical insulating composition 3, followed by the application of an electrical insulating composition 5, on which the second is applied. insulation layer 6 of quartz filaments, followed by application of electrical insulating composition 7.

In the manufacture of heat-resistant winding wire for power plants, the following materials can be used:

- bimetallic wire brand PBMM AS (TU 16.K03-64-2020);

- wire made of alloy BrKhNb 0.4-0.25 (alloy 204) or BrKhNb 0.2-0.1 (alloy 204 A) (TU 24.44.23.000-12574667731-2017);

- glass thread brand KS (TU 5952-196-05786904-2009);

- organosilicate composition brand OS-82-05 (TU 84-725-78).

The wire is made according to traditional technology and equipment used in the production of winding wires with fiberglass insulation.

A layer of electrical insulating composition 3 is applied to the conductive core 1, having a sheath 2. Then the first insulation layer 4, made of quartz filaments in the form of a braid, is applied on a horizontal glass winding machine. After applying the first layer of insulation 4 to the copper conductive core 1, having a sheath 2, a layer of electrical insulating composition 5 is applied. layers of insulation and impregnation with electrical insulating compound 3 and electrical insulating composition 5, 7, the wire is dried in a drying oven.

Claims (1)

Heat-resistant winding wire for power plants, containing a conductive core insulated with layers of insulation, layer-by-layer and superficially impregnated with an electrical insulating composition, characterized in that the conductive core is made in a sheath of austenitic steel, and the insulation is made in the form of a braid of quartz filaments.

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