EP2063445B1 - Improved high-voltage circuit breaker with gas release - Google Patents

Description

TECHNICAL FIELD AND PRIOR ART

The invention relates to the field of high-voltage circuit breakers under metal tanks, type GIS (Gas Insulated Switchgear) or Dead tank type. These circuit breakers can be part of a metal enclosure.

The invention relates more particularly to a method for evacuating the hot gases generated by a break in such a circuit breaker and the associated circuit breaker structure.

In this type of circuit breaker, for some short-circuit current values that correspond to a maximum fault current, the hot gases (i.e., plasma and exhaust gases) generated can promote reboots between the various live cut-off parts and the parts connected to the earth such as the metal tank.

In metal cased circuit breakers currently marketed, different types of exhaust or exhaust arrangements are provided.

A first type of arrangement, for example provided on Japanese type circuit breakers, such as that disclosed in the patent application JP2003217411 , comprises a short tube implanted at the outlet of the nozzle blowing hot gases and which also makes it possible to blow these directly into the metal tank. The dielectric insulation is obtained by maintaining great distances between the discharge ring formed with the tube and the metal tank.

A second type of arrangement, for example provided on the "Dead tank" as published in the patent application EP1806760 , allows to have a volume of dielectric gas present in the metal part of the exhaust sufficiently large to absorb all the hot gases generated during the longest arc period of the maximum short-circuit current. This exhaust arrangement includes lateral openings on the side through which the hot gases escape into the interior of the metal vessel.

The first type referred to above encloses volumes of insulating gas which are by construction less than the amount of hot gases blown during a break. Therefore, larger overall dimensions of the metal tank than the second type are provided because these hot gases are discharged in an uncontrolled manner, and therefore dimensional safety margins must be taken to ensure dielectric strength to the tank.

The closure provided in the arrangement of the second type involves a sufficient volume to keep the hot gases inside the metal part of the exhaust. Also, the dimensional safety margin between the outside of the exhaust and the metal tank can be reduced.

The documents US 4'236'053 , DE 9314779 and DE 2947957 as for them, disclose means for cooling hot gases through heat exchangers comprising solids. Heat exchanges are limited to the only exposed surface of the parts and require time.

The document EP1185996B1 discloses an exhaust structure with an alternation of means for varying the section through which the hot gas flow passes on its exhaust path and thus cool before its exit to the longitudinal end of the surrounding contact tube the fixed arc contact.

Finally, the document EP-A-1 768 150 discloses a method and a circuit breaker according to the preambles of claims 1 and 2.

In order to purge the cutoff gases between the satisfactory arc contacts, it is not recommended to use the section variations described in this document.

The object of the invention is to further reduce the overall dimensions of the exhaust or evacuation of hot gases and also to further reduce the dimensions of the metal vessel.

Another object of the invention is to provide a hot gas evacuation solution which has satisfactory cooling while maintaining a satisfactory purge of the cutoff gases between the arcing contacts.

STATEMENT OF THE INVENTION

To do this, the object of the invention is a process according to Claim 1, namely a method for evacuating hot gases from a break in a high-voltage circuit breaker, comprising a tank metal filled with insulating gas, an envelope comprising gas outlet openings and arranged inside the metal vessel communicating through the openings.

According to the invention, insulating gas is sucked from the inside of the casing, parallel to all the hot gas flows from the cut, so as to mix them inside the casing, before their evacuation. through the gas outlet openings of the casing and towards the inside of the metal tank.

According to the invention, therefore, insulating gas present before cut-off is used in the circuit breaker exhaust structure, a gas which by definition is colder than the hot gases from the cut-off and blends with said hot gases before they escape. towards the inside of the tank. In the circuit breaker structures of the prior art, the cold insulating gas already present in the exhaust is simply pushed into the interior of the metal tank by the hot gases, which therefore undergo no cooling by mixing with the insulating gas.

The invention is particularly interesting for very large fault currents, i.e. maximum fault currents and the longest arc durations.

The invention also relates to a high voltage circuit breaker according to claim 2, particularly adapted to the implementation of the method according to the invention.

• une cuve métallique remplie d'un gaz isolant,
• une enveloppe comprenant des ouvertures de sortie de gaz, l'enveloppe étant agencée à l'intérieur de la cuve métallique en communiquant par les ouvertures,
• une paire de contacts d'arc dont au moins un mobile en translation selon un axe, qui est solidaire d'une buse isolante pour souffler des gaz chauds générés lors de la séparation des contacts,
• des moyens pour aspirer du gaz isolant, depuis l'intérieur de l'enveloppe, parallèlement à la totalité de flux de gaz chauds soufflés lors de la séparation des contacts, de manière à les mélanger à l'intérieur de l'enveloppe avant leur évacuation par les ouvertures de sortie de gaz de l'enveloppe et vers l'intérieur de la cuve métallique.

According to the invention, it comprises:

• a metal tank filled with an insulating gas,
• an envelope comprising gas outlet openings, the envelope being arranged inside the metal tank by communicating through the openings,
• a pair of arcing contacts at least one mobile in translation along an axis, which is integral with an insulating nozzle for blowing hot gases generated during the separation of the contacts,
• means for sucking insulating gas from the inside of the casing parallel to the entire flow of hot gas blown during the separation of the contacts, so as to mix them inside the casing before their evacuation through the gas outlet openings of the casing and towards the inside of the metal tank.

• un fourreau entourant le contact fixe et agencé à l'intérieur de l'enveloppe en délimitant un passage débouchant,
• au moins un élément formant déflecteur, agencé à l'intérieur du fourreau, de sorte que les gaz chauds aspirent du gaz isolant depuis le passage débouchant, le(s) déflecteur(s) dévie(nt) le gaz isolant aspiré parallèlement au flux de gaz chauds et, le gaz isolant aspiré et dévié se mélange avec les gaz chauds à l'intérieur de l'enveloppe.

According to the invention, the circuit breaker comprises, as insulating gas suction means:

• a sheath surrounding the fixed contact and arranged inside the casing delimiting an opening passage,
• at least one baffle element, arranged inside the sheath, so that the hot gases suck insulating gas from the opening passage, the deflector (s) deflects (s) the insulating gas sucked parallel to the flow of hot gases and, the insulated and deflected insulating gas mixes with the hot gases inside the envelope.

The deflector (s) thus provided within the scope of the invention thus force the insulating gas, sucked from the opening passage, to be completely deflected and to flow parallel to the flow of hot gases generated by blowing before their subsequent mixing inside the envelope and their exit through the openings provided.

According to an advantageous variant, the gas outlet openings are made at one of the longitudinal ends of the envelope.

The opening passage comprises a plurality of holes distributed uniformly at the periphery of the sheath. Thus, when the gas outlet openings are made at the periphery of the casing, the hot gases leaving the nozzle blowing the gas at high speed can suck the colder insulating gas from the outside of the exhaust (that is, that is, between the sheath and the casing) and through the portion of the gas return passage (i.e. from the bowl to the apertures) and the through-holes.

According to a variant which does not form part of the invention, two deflectors coaxial with respect to the axis of translation of the moving contact are provided, one of the two baffles comprising at least one indentation made at one of its ends. longitudinal, the arrangement formed between the casing, the sheath and the two baffles creating a baffle insulating gas supply by the notch.

One of the two arcing contacts is fixed to the casing and the other is movable in translation along the axis.

According to a variant, which does not form part of the invention, the two arc contacts are movable in translation along an axis.

A variant, which is not part of the invention, finally relates to a circuit breaker module as described above, which comprises the casing, the sheath and the baffles.

• deux pièces moulées dont :
  • une forme un couvercle comprenant les ouvertures de sortie des gaz,
  • l'autre comprend une base à laquelle peut être fixé le contact d'arc fixe et forme une partie du fourreau et un des deux déflecteurs qui comprend une partie dans laquelle la buse isolante peut coulisser,
• trois pièces tubulaires formant respectivement l'enveloppe, l'autre partie du fourreau et l'autre déflecteur, réalisées chacune à partir d'une feuille roulée.

According to a variant, which does not form part of the invention, the module can be obtained from five metal parts assembled together, of which:

• two molded parts including:
  • a form a cover comprising the gas outlet openings,
  • the other comprises a base to which the fixed arcing contact can be fixed and forms a part of the sheath and one of the two deflectors which comprises a part in which the insulating nozzle can slide,
• three tubular parts respectively forming the envelope, the other part of the sleeve and the other baffle, each made from a rolled sheet.

• trois pièces moulées dont :
  • une forme un couvercle comprenant les ouvertures de sortie des gaz,
  • une autre forme une partie du fourreau et une partie d'un des déflecteurs et comprend une base à laquelle peut être fixé le contact d'arc fixe,
  • et une dernière comprenant l'autre partie d'un des déflecteurs dans laquelle la buse isolante peut coulisser,
• trois pièces tubulaires formant respectivement l'enveloppe, une partie du fourreau et l'autre partie du fourreau, réalisées chacune à partir d'une feuille roulée.

The module can also be made from six metal parts assembled together, including:

• three molded parts including:
  • a form a cover comprising the gas outlet openings,
  • another form a part of the sheath and a part of one of the deflectors and comprises a base to which the fixed arc contact can be fixed,
  • and a last one comprising the other part of one of the baffles in which the insulating nozzle can slide,
• three tubular pieces respectively forming the envelope, a portion of the sleeve and the other part of the sleeve, each made from a rolled sheet.

Such modules are advantageous because they are of a lower cost of implementation because, in particular, the molding of parts is reduced and the assembly between the different parts is simplified.

The module comprising six metal parts has the advantage of having simpler moldings.

BRIEF DESCRIPTION OF THE DRAWINGS

• la figure 1 est une vue schématique, en coupe longitudinale, d'un disjoncteur selon un mode de réalisation de l'invention,
• la figure 2 est une vue de face d'un module de disjoncteur selon une variante qui ne fait pas partie de l'invention,
• les figures 2A, 2B, 2C et 2D sont des vues en coupe longitudinale de la figure 2 respectivement selon les plans AA, BB, CC et DD,
• la figure 3 est une vue de face d'un module de disjoncteur selon une variante qui ne fait pas partie de l'invention,
• les figures 3A à 3E sont des vues en perspective représentant les différentes pièces du disjoncteur selon la figure 3,
• la figure 3F est une vue partielle en coupe longitudinale de la figure 3 selon le plan FF.

Other advantages and characteristics will emerge more clearly on reading the detailed description given with reference to the appended figures in which:

• the figure 1 is a schematic view, in longitudinal section, of a circuit breaker according to one embodiment of the invention,
• the figure 2 is a front view of a circuit breaker module according to a variant which does not form part of the invention,
• the Figures 2A, 2B, 2C and 2D are views in longitudinal section of the figure 2 respectively according to plans AA, BB, CC and DD,
• the figure 3 is a front view of a circuit breaker module according to a variant which does not form part of the invention,
• the FIGS. 3A to 3E are perspective views representing the different parts of the circuit breaker according to the figure 3 ,
• the figure 3F is a partial view in longitudinal section of the figure 3 according to the FF plan.

DETAILED PRESENTATION OF PARTICULAR EMBODIMENTS

On the figure 1 , in longitudinal sectional view, a circuit breaker 1 is shown in a metal envelope (GIS). This high-voltage circuit breaker 1 comprises a metal tank 2 filled with an insulating gas (GI), an envelope 3 comprising gas outlet openings 30. The envelope is arranged inside the metal tank and communicates with the gas outlet openings for evacuating insulating or hot gases (GI and GC represented by the arrows). More exactly, in this embodiment according to the figure 1 , the gas outlet openings are made at the periphery of the casing 3 near its longitudinal end 3b which is closest to the cutoff zone.

The circuit breaker 1 also comprises a pair of arcing contacts of which only the fixed contact 40 is represented ( figure 1 ) and is fixed to the casing 3. The other movable contact in translation along the axis XX ' is integral with an insulating nozzle 41 provided for blowing hot gases generated during the separation of the contacts.

According to the invention, there are provided means 5 for sucking insulating gas GI from the inside of the casing 3, parallel to the flow of hot gases GC blown during the separation of the contacts, so as to mix them (GI and GC) inside the casing before their evacuation through the gas outlet openings of the casing 3, towards the inside of the metal tank 2.

In the embodiment of the figure 1 , the suction means 5 comprise a sheath 50 surrounding the fixed contact 40 and arranged inside the casing 3 by defining a through passage 6 via a plurality of through holes 500 distributed uniformly to the The suction means also comprise a single deflector in the form of a tubular portion 51, arranged inside the sheath, so that the hot gases (GC) suck insulating gas (GI) from the holes 500, that is to say exclusively from inside the casing 3, the baffle 51 deflects the insulating gas (GI) sucked parallel to the flow of hot gases. The arrangement of the deflector 51 in the sheath 50 is thus provided so that only the insulating gas (GI) coming from the inside of the casing 3 is sucked up and not for example the gases at the periphery of the nozzle 41. Then, the insulated and deflected insulating gas mixes with the hot gases inside the casing 3.

Thus, according to the embodiment illustrated in figure 1 , the hot gases GC leaving the nozzle 41 at high speed can suck the insulating gas, colder, respectively, from the outside of the exhaust (that is to say between the sleeve 50 and the envelope 3 ), through the portion of the gas return passage (i.e. from the bowl 3a to the side openings) and then through the through holes 500.

On the variant of Figures 2 to 2D , as well as that of Figures 3 to 3F , the gas outlet openings 30 are made at one of the longitudinal ends 3a of the casing 3 and the suction means comprise two baffles 51, 52 coaxial with the axis XX 'of translation of the movable contact and of the nozzle 41, one of the two deflectors 52 comprising a plurality of notches 520 made at one of its longitudinal ends 52a, the arrangement formed between the casing, the sleeve and the two baffles 51, 52 creating a baffle 7 insulating gas supply by the notches 520 (see bent arrows on Figures 2A and 2C for example).

More precisely, in these two variants shown, one of the two baffles 51 comprises two parts of the walls 510, 511 parallel to each other. The other deflector 52 is arranged between these two parts of the walls 510, 511 parallel so that the insulating gas supply baffle, or suction baffle 7, is shaped in Z with the interior of the sleeve 50 parallel to the wall 511 (see for example the Figure 2A ).

In the variant illustrated in Figures 2A to 2D , the module 8 according to the invention is obtained from six metal parts interleaved and screwed together. Of these, three pieces are molded. One forms a cover 80 including the gas outlet openings 30. The other part 81 forms part of the sheath 50 with a base 50A to which the fixed arcing contact can be fixed, and a part 511 of one of the two deflectors 51. The last molded part comprises another part 510 of the deflector 51 in which the nozzle 41 can slide. Finally, three tubular pieces respectively form the envelope 3, the other part of the sleeve 50 and the other deflector 52, each made from a rolled sheet.

In the variant illustrated in Figures 3 to 3F , the module 8 'according to the invention is obtained from five metal parts nested and screwed together. Of these, two pieces are molded ( FIG. 3A and FIG. 3B ). One forms a lid 80 'comprising the gas outlet openings 30 ( figure 3A ). The other part 81 'forms part of the sleeve 50 with a base 50A to which the fixed arc contact 40 can be fixed. The other part comprises integrally one of the two baffles 51, a part 510 in which the insulating nozzle can slide. Finally, three tubular pieces respectively form the envelope 3 ( figure 3C ), the other part of the sleeve 50 ( 3D figure ) and the other baffle 52 ( figure 3E ), each made from a rolled sheet.

In other words, the suction means 5 which are provided in the different embodiments are mechanical means which, as arranged in the metal vessel, consist in producing a suction of all the hot gases by the cold insulating gases. Thus, to obtain optimal suction, the mechanical means provided (deflector (s)) can define paths traveled on the one hand, by the hot gases from the blowing nozzle to the outlet of the tank and other on the other hand, by the cold insulating gases from their suction inlet (baffle inlet 7 in the embodiment of the figure 2 ) to the outlet of the tank which are approximately the same length.

Calculations have shown that the implementation of the method according to the invention on a circuit breaker was effective. In particular, it has been calculated that the static pressure inside the exhaust which guides the hot gases from the insulating nozzle was lower than the pressure prevailing between the exhaust (shell) and the metal tank.

Thanks to the invention, it shortens the exhaust of a high-voltage circuit breaker, which also reduces the longitudinal size of the associated metal vessel. This is particularly important in order to meet the transport requirements, before their installation in-situ, tanks called "Dead Tank".

Claims (3)

1. A method of evacuating hot gases produced in a current breaking operation, by a high voltage circuit breaker (1) which comprises a metal outer tank (2) filled with insulating gas,
   a casing (3) having gas outlet ports (30) and arranged inside the metal tank (2), communicating via the said ports,
   a pair of arcing contacts (4), one of which (40) is fixed and one of which is movable in translation along an axis (XX'), this movable contact being fixed to an insulating nozzle (41) for blowing out hot gases generated in the separating of the contacts;
   wherein insulating gas (GI) is aspirated from inside the casing (3) in a direction parallel to the totality of the flow of the hot gases (GC) produced by the current breaking operation, so as to mix the gases inside the casing (3) before they are evacuated, through the said gas outlet ports (30) of the casing, into the interior of the metal outer tank (2),
   characterized in that:

   - ·a sheath (50) surrounds the fixed contact (40) and is arranged inside the casing (3) to define an open passage (6), comprising a plurality of holes (500) spaced apart uniformly at the periphery of the sheath (50) to allow aspiration of insulating gas (GI),

   - ·at least one deflector element (51, 52) arranged inside the sheath and being such that the hot gases (GC) aspirate insulating gas (GI) from the open passage (6), with the or each deflector (51, 52) diverting the aspirated insulating gas (GI) in a direction parallel to the hot gas flow, and the insulating gas thus aspirated and diverted mixing with the hot gases inside the casing (3).
2. A high voltage circuit breaker (1) comprising:

   - ·a metal tank (2) filled with an insulating gas;

   - ·a casing (3) having gas outlet ports (30), the casing being arranged inside the metal tank, communicating via the gas outlet ports for the purpose of evacuating gases (GI and GC);

   - ·a pair of arcing contacts (4), one of which (40) is fixed and one of which is movable in translation along an axis (XX'), this movable contact being fixed to an insulating nozzle (41) for blowing out hot gases generated in the separating of the contacts; and

   - ·means (5) for aspirating insulating gas (GI) from inside the casing (3) in a direction parallel to the totality of the flow of hot gases (GC) blown out in the separating of the contacts, whereby to mix the gases (GI and GC) inside the casing before they are evacuated, through the gas outlet ports (30) of the casing (3), into the interior of the metal tank (2),

   characterized in that said means (5) for aspirating insulating gas comprise:

   - ·a sheath (50) surrounding the fixed contact (40) and arranged inside the casing (3) to define an open passage (6), comprising a plurality of holes (500) spaced apart uniformly at the periphery of the sheath (50) to allow aspiration of insulating gas (GI),

   - ·at least one deflector element (51, 52) arranged inside the sheath and being such that the hot gases (GC) aspirate insulating gas (GI) from the open passage (6), with the or each deflector (51, 52) diverting the aspirated insulating gas (GI) in a direction parallel to the hot gas flow, and the insulating gas thus aspirated and diverted mixing with the hot gases inside the casing (3).
3. A circuit breaker (1) according to claim 2, wherein the gas outlet ports (30) are formed either at one longitudinal end (3a) or at the other longitudinal end of the casing (3).

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