RU2685542C2 - Sealed input of power electrical conductors through a protective shell - Google Patents

Abstract

FIELD: electrical engineering.SUBSTANCE: invention relates to the field of electrical engineering and electric power industry and, in particular, to the structures of power hermetic electrical inputs and can be used in various electrical and energy technology installations and apparatus, for example, at nuclear power plants. Device is designed to enter the power electrical circuits in sealed rooms or volumes with normal atmospheric pressure, for example, in the sealed zone of the containment of a nuclear power plant with any type of reactor. Sealed input of power electrical conductors through a protective sheath containing an internal sealing unit formed by combining two sealing sleeves in the input through a central metal pipe of the input case with a rigid current guide passing inside it, hermetically passing inside one or more centering couplings with its subsequent hermetic transmission through side dielectric pipes and composite bushing insulators, covered by a central dielectric pipe, which is the main fence of the main biological protection circuit, reinforced by common bushings input.EFFECT: invention provides increased reliability and increased functionality of the electrical input.1 cl, 5 dwg

Description

The invention relates to electric power devices and can be used to transmit electrical energy through cables, wires, harnesses of various designs in sealed systems with fire resistance, seismic resistance and radiation protection, for example, in nuclear power plants, chemical reactors, test benches and other similar objects and building structures.

H01B 17/26) в герметичную зону атомных электростанций, содержащее изолирующий многоканальный элемент, расположенный в закладной трубе соосно с электрическими проводниками, проходными изоляторами, закрепленными на фланцах по обе стороны закладной трубы.A device for transmission of electrical conductors (invention according to application 2656406 / 24-07

H01B 17/26) into the hermetic zone of nuclear power plants, containing an insulating multi-channel element located in the inset pipe coaxially with electrical conductors, bushing insulators fixed on the flanges on both sides of the inset pipe.

The disadvantage of this device is element-by-element assembly in a protective shell, the lack of continuous monitoring of tightness, the possibility of moisture inside the device and at the same time there is a decrease in electrical parameters, the complexity of installation and dismantling.

Closest to the technical nature stated in this application device is a tight input of electrical conductors through the protective sheath (RU 2322717 C1).

The sealed lead in the given patent contains a metal case inside which in a cement mixture there are ceramic tubes reinforced with their inside conductors with a flexible insert, bushing insulators hermetically connected to the flanges welded hermetically at the ends of the case, and hermetic casing. Some improvements in the electromechanical characteristics of the pressure input are achieved by:

Filling under the overpressure of the internal free space of the body with dry nitrogen, gas and their mixture

The disadvantages of the considered analog is the following:

- the internal volume of the metal case of the hermetic input when the electric conductors are passed through is not effectively used.

- the use of cement-sand mixture as a reinforcing element of ceramic tubes and as radiation protection inside the hermetic inlet volume reduces the electrical insulating properties of ceramic bushing insulators during operation and reduces the reliability of the inlets as a whole.

The closest analogue, the technical base for the claimed in this application of the invention is patent No. 2572824 RU Block sealed input for this patent provides for blockiness of the construction with the number of blocks n = 1, 2, ... The sealing assembly also consists of sealing clips, arranged both perpendicularly and parallel to the input axis. But while in the formula itself there are no restrictions on the angle in question in the block input and this angle can be in the range of 0 ÷ 90 degrees. In addition, in this patent No. 2572824 there are also no restrictions on the distance between the block holders in the direction of its reduction to the minimum possible value, determined only by the need to carry out technological operations for sealing the junction of metallic insulator fittings (caps) with rigid tokovods passing inside the insulators.

In the existing constructions of power hermetic inputs of electrical conductors through a protective sheath (patent No. RU 2322717), temperature compensation of the temperature extensions of tokovods appearing during operation is carried out using composite tokovodov. Composite tokovods are flexible strings of a given length (stranded conductor), at the ends of which, by means of soldering and welding, segments of a hard current lead are connected with which the metal fittings of the lead-through insulators of the lead-in insulators are hermetically connected. In this patent, the distance between the flanges (sleeves) of the input is determined by the thickness of the protective sheath, reaching 1500 cm and thereby determining the length of the composite tokovod itself. Electrical isolation of the tokovod is carried out by placing it inside a ceramic pipe, fixed by cement mortar inside a sealed volume of a metal input casing. During the operation of these inputs, the cement mixture is dried out and dehydrated; humidity inside the hermetic volume increases, dust-like inclusions appear, which are deposited on the insulating surfaces of insulators and reduce the electrical insulating characteristics of the power hermetic inputs.

Thus, the aim of the claimed invention is to improve the electrical insulating characteristics of the hermetic input, increase its functionality, increase the reliability of the design. The claimed invention will increase the number of conductors of electrical conductors in the sealed input unit, while the number of blocks can be equal to n = 1, 2, ... The utility model allows to increase the reliability of the pressure seals, increase their radiation (biological) protection and fire resistance.

These technical results are achieved by the fact that the invention can be technically realized, which is a sealed input of power electrical conductors of fig. 1 through a protective sheath containing an internal sealing assembly formed by combining two sealing sleeves 2 in the inlet by means of a central metal pipe 21 of the entry housing with a rigid current conductor 5 passing inside its linear or special profile, tightly passing inside one or more centering sleeves 9, followed by hermetically passing through the side dielectric pipes 20a and composite bushing insulators 1, covered by a central dielectric pipe 20, which is the outline of the fence for the ovine biological protection 15 in the internal sealing unit, reinforced with common clips 2 pressure seals, secured in supporting flanges 8, installed in side metal pipes 22, hermetically connected on the holders 2 inputs to the central metal pipe 21 and mechanically 13 fixed with protective covers 12 inside which on the “clean zone” side, there is a remote control connection 18 with a leak test tube 17, passing through the additional biological protection 15 to the internal sealing assembly Yes.

From the presented input design fig. 1 that the sealing unit 2, 21 is located directly inside the inlet, at a considerable distance from the enclosing outer surfaces of the containment shell, which in the case of a fire situation at the facility excludes the effect of high temperatures on the considered unit. Another important element for all high-voltage inputs is the method of compensating for the temperature expansion of the current leads when passing load currents. In the sealed power unit invention presented by us, this problem is solved by installing special couplings (9) together with bellows temperature compensation 4a on composite bushing insulators using a bent rigid current lead of a special configuration in the middle part of the sealing assembly between the centering couplings (Fig. 1a).

When developing highly reliable tight inputs, apparently, it is necessary to be guided by the following provisions:

узлы герметизации, как наиболее уязвимые при пожаре элементы ввода, должны располагаться внутри конструкции ввода, то есть внутри самой защитной оболочки, выполненной из бетона.

sealing units, as the most vulnerable in the event of a fire input elements, should be located inside the input structure, that is, inside the protective shell made of concrete.

жесткие тоководы, являющиеся сплошными металлическими стержнями, должны иметь компенсаторы термических расширений оптимальной конфигурации.

rigid tokovods, which are solid metal rods, must have thermal expansion compensators of optimal configuration.

в качестве электрической изоляции вводов должна выбираться высоконадежная изоляция из проходных составных изоляторов, используемых, как самостоятельно, на примере вводов рис. 1, так и совместно с другой диэлектрической средой при формировании в конструкциях вводов участков литых тоководов, образуемых методом вакуумной заливки диэлектрическим радиационностойким компаундом на основе кремний-органических материалов с минеральным наполнителем.

highly reliable insulation should be chosen as the electrical insulation of the bushings from the composite insulators through passage, used independently as an example, using the inputs of fig. 1, and in conjunction with another dielectric medium when forming in the designs of bushings sections of cast tokovods formed by the method of vacuum filling with a dielectric radiation-resistant compound based on silicon-organic materials with mineral filler.

с торцевой арматурой 4 следующего изолятора, образуя заданное количество секций изолятора, определяемое необходимой величиной разрядных напряжений. При этом реализуется принцип конструирования составных проходных изоляторов по типу «подвесной изоляции», широко используемой в энергетике на линиях электропередачи.The most complex element in the design of the input of Fig. 1, “Sealed input of power electroconductors through a protective sheath”, is a pass-through composite insulator. Pass-through composite insulator 1 provides electrical isolation of the current lead 5 from the metal cage 2 input. The design of the composite bushing 1 includes a tubular insulating body, which is hermetically connected to metal reinforcement 3, 4 by means of reinforcement. clip 2 input. At the same time, in the construction of hermetic inlet, composite reinforced bushing insulators are used, when typical reinforced bushing insulators are connected in series with each other, and end fittings 4 of the previous insulator

with end fittings 4 of the next insulator, forming a specified number of insulator sections, determined by the required value of discharge voltages. In this case, the principle of constructing composite bushing insulators of the type of “suspension insulation”, widely used in power engineering on power lines, is implemented.

In the hermetic input of rice. 1, temperature compensation for linear displacements of a rigid conductor is provided in the internal sealing assembly.

In the composite bushing, the armature of two adjacent sections has a specific configuration, which allows for mounting the sections by laser welding (welding seam, position 4a) to obtain in the composite insulator a bellows compensator for linear displacements of the hard current conductor.

Где;

- коэф. термического расширения,The distance AB, equal to the length of the centering coupling, on the current path between the end fittings 3 of two adjacent composite insulators input fig. 1 is chosen in advance as low as possible, in this case equal to 0.1 m. The relation between the elongation of the metal rod and its heating temperature is known:

Where;

- coefficients thermal expansion,

- длина токовода, °С

- the length of the current lead, ° C

t - tokovod temperature, ° C

будем иметь минимальное удлинение токовода на участке AB и минимально возможные механические нагрузки в местах герметичного соединения арматуры составного изолятора с центрирующей муфтой 9. Влияние указанной компенсации может быть усилено за счет введения на участке AB токовода рис. 1 специальных типов компенсаторов:At the lowest possible distance

we will have the minimum elongation of the current conductor in section AB and the minimum possible mechanical loads in the places of tight connection of the reinforcement of the composite insulator with centering coupling 9. The influence of this compensation can be enhanced by introducing the current conductor in section AB. 1 special types of compensators:

- zigzag, - spiral, - sawtooth and others, formed by mechanical deformation of the metal rod of the tokovod. When using the above versions of compensators, the design of the centering coupling splits into two similar coupling halves 9, in the gap between which, in the section AB, compensating devices are formed from a rigid conductor.

Based on the above information, fig. 1, the construction of the invention “The introduction of a sealed power electrical conductors through a protective sheath” is expanded due to the additional performance versions of this model, proposed in fig. 1a, fig. 1b, fig. 1c, fig. 1g.

In fig. 1a, a “Hermetic input of power cast current leads with a spiral compensator of thermal expansion” is presented. The temperature compensation unit (24) and the internal sealing unit are located inside the input. In contrast to the basic design of the hermetic input of fig. 4, the spiral-shaped compensator is located between two similar coupling halves 9, and the biological protection (concrete) directly in the internal sealing assembly is replaced by the technology of vacuum filling of compounds with material 19 based on the known radiation-resistant organosilicon compounds. The presented scheme allows you to implement a block version of the design of hermetic power input.

The design of fig. 1b "Hermetic input of power cast current leads with L - shaped compensator of thermal expansion" differs from the schemes of hermetic inputs of fig. 1, Fig. 1a using an L-shaped thermal expansion compensator, allows you to create a block version of a pressure seal.

In fig. 1c implemented the “Sealed input of power cast current leads, mineral-insulated cables with a zigzag compensator for thermal expansion”. In this variant of the hermetic inlet, the cast-iron conductor itself (26) itself is a compensator for thermal expansion, the sealing assembly (1) is brought into the input casing,

The information in fig. 1g "Block multichannel hermetic inlet of power cast current conductors with a U-shaped compensator for thermal expansion of electrical conductors" characterizes the design with the number of channels n = 1, 2, ...

The main advantages of the newly developed invention are the hermetic insertion of electric power conductors through a protective sheath:

разработан вариант силового электроэнергетического устройства, в том числе и в блочном исполнении, позволяющий максимально полно использовать полезный внутренний объем закладной трубы ввода для увеличения в 1,5÷2 раза количества пропускаемых через герметичный ввод силовых электропроводников класса напряжений 0,4÷10 КВ в сравнении с аналогом.

A version of a power electropower device, including a block version, has been developed, which makes it possible to make the most of the useful internal volume of the inlet pipe to increase by 1.5 ÷ 2 times the number of power voltage class 0.4 ÷ 10 KV passed through a hermetic input compared to with analog.

исключение непосредственно из внутреннего герметизирующего узла ввода цементных растворов значительно улучшает электроизоляционные характеристики вводов

exclusion directly from the internal sealing unit for the introduction of cement mortars significantly improves the electrical insulating characteristics of the inputs

Designation of sealed entry positions:

уменьшение расстояния между обоймами блока до достаточной величины порядка 0,1 м. с надежной дополнительной изоляцией рассматриваемого промежутка позволяет создать герметичные вводы со стабильным и надежным уровнем изоляции внутри герметичного объема ввода

reducing the distance between the clips of the block to a sufficient size of about 0.1 m. with reliable additional insulation of the considered gap allows you to create sealed glands with a stable and reliable level of insulation inside the sealed volume of the input

использование в конструкции ввода температурной компенсации на составных проходных изоляторах, на различных схемах: спиралеобразных, зигзаго образных, пилообразных и других видах компенсаций позволяет надежно и эффективно решить проблему компенсирования механических нагрузок, возникающих в процессе эксплуатации в тоководах и проходных изоляторах в результате воздействия термических расширений, прохождения токов короткого замыкания

The use of temperature compensation in the construction of composite bushing insulators, on various schemes: spiral-shaped, zigzag, sawtooth and other types of compensation allows reliably and effectively solving the problem of compensating the mechanical loads that occur during operation in tokovods and bushing insulators as a result of thermal expansions passage of short circuit currents

все пожароопасные зоны герметизации вводов находятся внутри блоков вводов, а торцевые выступы боковых металлических труб вводов с выходящими из них кабелями дополнительно герметизируются на расчетную длину бетоном, герметиком холодного отвердевания и др.

all fire-hazardous zones of sealing of the bushings are inside the bushings, and the end protrusions of the side metal tubes of the bushings with cables coming out of them are additionally sealed to the calculated length with concrete, cold-curing sealant, etc.

использование различных схем температурной компенсации позволяет увеличить количество типоисполнений герметичных вводов по предлагаемому изобретению.

The use of various temperature compensation schemes allows to increase the number of types of sealed bushings according to the invention.

использование в конструкции герметичных вводов литых токопроводников, образуемых при вакуумной пропитке, заливке элементов ввода кремний-органическими радиационностойкими компаундами с минеральными наполнителями позволит усилить уровень электрической изоляции и герметичности изделий данной полезной разработки

the use in the design of hermetic bushings of molded current conductors formed during vacuum impregnation, the pouring of the input elements with silicon-organic radiation-resistant compounds with mineral fillers will enhance the level of electrical insulation and tightness of products of this useful development

применение силовых герметичных вводов позволяет получить значительный экономический эффект на объектах атомной энергетики.

the use of power sealed bushings allows to obtain a significant economic effect at nuclear power facilities.

Claims (2)

1. Sealed inlet of power electrical conductors through a protective sheath containing an internal sealing unit formed by combining two sealing sleeves in the input through a central metal pipe of the input case with a linear rigid current lead passing inside it, hermetically passing inside one or more centering sleeves with its subsequent hermetic transmission through side dielectric pipes and composite bushing insulators, covered by a central dielectric pipe, which is the circuit fences of the main biological protection, reinforced with common bushings of the input, with fastening in supporting flanges installed in side metal pipes, hermetically connected to the inlet cages with the central metal pipe and mechanically fixed with protective covers, inside which there is a remote control fitting on the “clean zone” side with a leak test tube passing through the additional biological protection to the internal sealing unit of the inlet. 2. Input according to Claim 1, characterized in that two centering couplings are tightly installed on the tokovod in a hermetic inlet in its middle part, in the gap between which a different type of thermal expansion expansion is formed from a rigid topox, for example: spiral-shaped, zigzag-shaped, sawtooth.

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