EP3767659A1

EP3767659A1 - Circuit breaker with improved exhaust cooling

Info

Publication number: EP3767659A1
Application number: EP19186329.9A
Authority: EP
Inventors: Michael Schwinne; Patrick Stoller; Bernardo Galletti; Martin Seeger
Original assignee: ABB Power Grids Switzerland AG
Current assignee: Hitachi Energy Ltd
Priority date: 2019-07-15
Filing date: 2019-07-15
Publication date: 2021-01-20
Also published as: JP3239773U; WO2021009148A1

Abstract

A circuit breaker which includes at least one quenching chamber is described. The quenching chamber is configured to be filled with insulating gas, extends along a longitudinal axis and includes an arcing zone and an exhaust zone. The exhaust zone is configured to dissipate hot insulating gases from the arcing zone into an exhaust tank. At least one deflection volume is enclosed by a deflection housing and is arranged within an inner volume of the exhaust zone. The at least one deflection volume is configured to fluidly connect the arcing zone with the exhaust tank through a plurality of openings within the deflection housing.

Description

TECHNICAL FIELD

Embodiments of the present disclosure relate to a circuit breaker, a method of operating a circuit breaker, and a method for cooling an exhaust fluid in a circuit breaker.

BACKGROUND

A high voltage circuit breaker is an automatically or manually operated electrical switch designed to protect an electrical circuit from damage caused by excess current from a short circuit and to switch load currents. The basic function of a high voltage circuit breaker is to interrupt current flow, for instance, after a fault is detected. Unlike a fuse, which operates once and then must be replaced, a high voltage circuit breaker can be reset (either manually or automatically) to resume normal operation.
In a high voltage circuit breaker, a current interruption process involves a mechanical separation of an electrical contact between terminals of an electric circuit carrying current inside the circuit breaker and, more specifically, in an arcing zone of the high voltage circuit breaker. When the separation occurs, an arc discharge between the electrodes in the arcing zone of the high voltage circuit breaker is established, wherein the nature and properties of the arc are dependent on a fluid, i.e. a gaseous medium, present between the open terminals of the high voltage circuit breaker. Examples of gaseous media commonly used in circuit breakers are air, sulphur hexafluoride (SF₆) and, more recently, carbon dioxide (CO₂).
After an arc discharge in a circuit breaker is established, the arc in the arcing zone of the circuit breaker has to be extinguished as quickly as possible before voltage builds up sufficiently to re-strike the arc. One option of extinguishing the arc is by quickly removing heat from the arc and arcing zone developed by ohmic heating of current passing through an arc resistance. Herein, the heat capacity of the gaseous medium in the arcing zone, and more particularly around the arc, mostly determines the time required to remove heat from the arc and arcing zone.
In a process to remove the heat from the arc and arcing zone, a gaseous medium is injected in the arcing zone of the high voltage circuit breaker. The gaseous medium can be cold (for example, in the case when low currents are interrupted), but can reach high temperatures in the range 1000 K to 2000 K. In a so-called puffer circuit breaker, the gaseous medium used for current interruption is compressed mechanically in a so-called puffer volume. The puffer volume is connected directly to the arc zone, so that hot gas from the arc zone also enters the puffer volume and mixes with the cold gas. The resulting "warm" gas is still much colder than the hot gas and plasma / "ionized gas" present in the arcing zone and can be used to effectively cool the arc. In a self-blast circuit breaker, the mechanically compressed cold gas in the "puffer volume" is separated from the hot gas injected from the arc zone into the "heating volume" via an intermediate valve. The intermediate valve closes above a certain threshold arc energy / pressure build-up in the heating volume. The mixing of cold, mechanically compressed gas with hot gas from the arcing zone in the "puffer volume" (puffer circuit breaker) or the "heating volume" (self-blast circuit breaker) happens during one or two or more AC half-waves of current. At the same time as this mixing is occurring (via gas from the arc zone flowing into the puffer / self-blast volumes), most of the hot gas from the arc is actually being exhausted from the arcing zone to the exhaust part of the circuit breaker and onward to the surrounding tank. Gas that enters the exhaust is not reused to cool the arc.
The key aspect of the design of the exhaust and the tank is to avoid dielectric breakdown between the exhaust (which is at high voltage) to the surrounding tank (which is grounded).
During conduction of the hot gaseous medium to an exhaust tank, the hot gaseous medium is dissipated (e.g. moves) axially with respect to an axis extending along the high voltage circuit breaker.
For obtaining high voltage circuit breakers with a high removal of heat from an arc and arcing zone there remain several challenges to be mastered. In particular, the introduction of more eco-friendly gaseous media (like CO₂) in high voltage circuit breakers in recent years has motivated the search for solutions (i.e. innovative designs) to improve the extinguishing (e.g. quenching) of the arc in the high voltage circuit breakers as the extinguishing performance of CO₂ is lower than the extinguishing performance of the most commonly used gaseous medium SF₆. In this regard, the installation of bigger tanks for rapidly uptaking the hot gaseous medium from the arc of high voltage circuit breakers is a very costly alternative.
Therefore, there is a continuous demand to provide high voltage circuit breakers containing more eco-friendly gaseous media and having improved extinguishing capacities, methods of operating a high voltage circuit breaker and methods for cooling an exhaust fluid in a high voltage circuit breaker.

SUMMARY

In light of the above, a circuit breaker, a method of operating a circuit breaker, and a method for cooling an exhaust fluid in a circuit breaker according to the independent claims are provided. The present disclosure aims to improve cooling the gas that leaves the arcing zone of a circuit breaker. In particular, the present disclosure aims to increase the heat transfer from an exhaust fluid to a deflection housing in a circuit breaker while the exhaust fluid is flowing from the arcing zone via an exhaust zone into an exhaust tank. Furthermore, the present disclosure aims to decrease a temperature of the exhaust fluid in an exhaust tank. Moreover, the present disclosure aims to extinguish an arc in a high voltage circuit breaker without the need of additional equipment.
Further aspects, advantages, and features are apparent from the dependent claims, the description, and the accompanying drawings.
According to an aspect of the present disclosure, a circuit breaker is provided which includes at least one quenching chamber. The quenching chamber is configured to be filled with insulating gas, extends along a longitudinal axis and includes an arcing zone and an exhaust zone. The exhaust zone is configured to dissipate (e.g. remove) hot insulating gas from the arcing zone into a tank. At least one deflection volume is enclosed by a deflection housing and is arranged within an inner volume of the exhaust zone. The at least one deflection volume is configured to fluidly connect the arcing zone with the exhaust tank through a plurality of openings within the deflection housing.
According to another aspect of the present disclosure, a method of operating a circuit breaker according to the present disclosure is provided. The method of operating a circuit breaker includes breaking an electric current by the circuit breaker.
According to another aspect of the present disclosure, a method for cooling insulating gas in a circuit breaker is provided. The circuit breaker includes at least one quenching chamber filled with insulating gas. The method includes conducting the insulating gas through at least one deflection volume. The at least one deflection volume is enclosed by a deflection housing which is arranged within an exhaust zone. The exhaust zone is configured to fluidly connect an arcing zone with an exhaust tank.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above recited features of the present disclosure can be understood in detail, a more particular description of the disclosure, briefly summarized above, may be had by reference to embodiments. The accompanying drawings relate to embodiments of the disclosure and are described in the following:

FIG. 1: shows a schematic cross-section of a portion of a high voltage circuit breaker 100 according to embodiments described herein;
FIG. 2: shows a schematic cross-section of a portion of a high voltage circuit breaker 200 according to according to embodiments described herein;
FIG. 3: shows a schematic cross-section of a portion of a high voltage circuit breaker 300 according to according to embodiments described herein;
FIG. 4: shows a schematic cross-section of a portion of a high voltage circuit breaker 400 according to according to embodiments described herein;
FIG. 5: shows a schematic cross-section of a portion of a high voltage circuit breaker 100, 200 according to according to embodiments described herein;
FIG. 6: shows a schematic cross-section of a portion of a high voltage circuit breaker 600 according to according to embodiments described herein;.

DETAILED DESCRIPTION OF EMBODIMENTS

Reference will now be made in detail to the various embodiments of the disclosure, one or more examples of which are illustrated in the figures. Within the following description of the drawings, the same reference numbers refer to same components. Only the differences with respect to individual embodiments are described. Each example is provided by way of explanation of the disclosure and is not meant as a limitation of the disclosure. Further, features illustrated or described as part of one embodiment can be used on or in conjunction with other embodiments to yield yet a further embodiment. It is intended that the description includes such modifications and variations.
According to some embodiments, which can be combined with other embodiments described herein, a circuit breaker is provided having at least one quenching chamber. In the present disclosure, the circuit breaker may be rotationally symmetrical.
In the present disclosure, a circuit breaker is typically a high voltage circuit breaker. The term high voltage relates to voltages that exceed 1 kV, and typically relates to nominal voltages in the range from 72 kV to 550 kV, for example about 145 kV, about 245 kV or about 420 kV. Nominal current ratings of a high voltage circuit breaker are typically in the range from 3 kA to 5 kA, for example about 3.15 kA or about 4 kA. The current, which flows during the abnormal conditions in which the high voltage circuit breaker performs its duty, may be interchangeably referred to as the switching current, the breaking current or the short circuit current. The switching current may be in the range from 31.5 kA to 80 kA, which is termed high short-circuit current duty. In low short-circuit current duties, the switching current is typically larger than the nominal current and smaller than 0.3 times the rated short-circuit current, e.g. is at most 24 kA. During a switching/breaking operation, switching/breaking voltages may be very high, e.g. in the range from 110 kV to 1200 kV.
According to some embodiments, the circuit breaker is typically a high voltage generator circuit breaker. The term high voltage when used in relation to a high voltage generator circuit breaker typically relates to nominal voltages in the range from 10 kV to 32 kV, for example about 15 kV, about 25 kV or about 31.5 kV. Nominal currents of a high voltage generator circuit breaker are typically in the range from 4 kA to 35 kA, for example about 4 kA or about 25 kA. The current, which flows during the abnormal conditions in which the high voltage generator circuit breaker performs its duty, may be interchangeably referred to as the switching current, the breaking current or the short circuit current. The switching current may be in the range from 50 kA to 300 kA.
In the present disclosure, a high voltage circuit breaker can be a self-blast circuit breaker, a generator circuit breaker, a puffer circuit breaker, or a gas-insulated circuit breaker, such as a gas insulated medium voltage circuit breakers and a gas insulated high voltage circuit breakers. Typically, the circuit breaker of the present disclosure is a gas-insulated high voltage circuit breaker using SF₆ alternative gases, such as e.g., CO₂ as insulating gases in the quenching chamber.
According to some embodiments, which can be combined with other embodiments described herein, the quenching chamber may contain at least two power contact pieces. According to an aspect, the power contact pieces may be part of a head to head contact system. According to another aspect, at least one of the power contact pieces may be in the form of a movable or stationary tubular hollow contact. The tubular hollow contact may further be provided as tulip contact on a side of the arcing zone.
According to some embodiments, which can be combined with other embodiments described herein, the quenching chamber of the circuit breaker extends along a longitudinal axis and contains at least one arcing zone and at least one exhaust zone. The arcing zone is typically a zone or volume of the quenching chamber where an arc discharge occurs upon separation of the two or more power contact pieces that are movable relative to one another along an axis. The axis may be a symmetry axis of the quenching chamber, in particular an axis of n-fold or continuous rotational symmetry. The short term "rotational symmetry" shall mean a continuous rotational symmetry. An n-fold rotational symmetry means a discrete symmetry regarding rotations by angles which are multiples of 360°/n, where n is an integer number larger than one. The term "axial" designates an extension, distance etc. in the direction of the axis. An axial separation between parts means that these parts are separated from each other when seen or measured in the direction of the axis. The term "sideways" is to be understood with respect to the axial direction. The term "radial" designates an extension, distance etc. in a direction perpendicular to the axis. The term "cross-section" means a plane perpendicular to the axis, and the term "cross-sectional area" means an area in such a plane. The exhaust zone is typically a zone or volume of the quenching chamber through which the hot insulating gases from the arcing zone are conducted into an exhaust tank.
According to some embodiments, which can be combined with other embodiments described herein, the exhaust zone is configured for dissipating hot insulating gases from the arcing zone into an exhaust tank. In particular, the exhaust zone may have an inner volume and may be configured to fluidly connect the arcing zone with the exhaust tank via specific means which contribute in cooling the hot insulating gases on their way from the arcing zone to the exhaust tank. Typically, the exhaust zone may have the same radial extension as the quenching chamber. The exhaust zone may have a radial extension that is smaller than the radial extension of the quenching chamber. The exhaust zone may share a wall with the quenching chamber. The exhaust zone may have an outer wall that has a smaller radial distance to the longitudinal axis than a wall of the quenching chamber. The outer walls of the quenching zone may be the outer walls of the exhaust zone, i.e. the inner surface of the outer wall of the quenching chamber may be equivalent to the outer surface of the exhaust zone.
According to some embodiments, which can be combined with other embodiments described herein, the exhaust zone may contain at least one deflection volume. A deflection volume as described herein may refer to a volume that deflects the flow direction of the hot insulating gases on their way from the arcing zone to the exhaust tank. In principle, deflection occurs when the hot gas flow contacts at least one wall of a deflection housing enclosing the deflection volume. Contacting a housing wall by a gas stream is also known as "impinging event". Such an "impinging event" leads to a heat transfer from the hot gases to the walls which finally results in cooling the hot gases to a certain degree. Cooling the gas flow is necessary since too high gas temperatures in the exhaust tank lead to dielectric failure. As such, the deflection volume may be enclosed by a deflection housing having housing walls. Since the gas flow of the hot insulating gases from the arcing zone to the exhaust tank gas should not be interrupted, it is required that the deflection housing comprises at least two (a plurality of) openings through which the gas can pass the deflection chamber. A "deflection volume" as described herein may further refer to a volume that has an inner surface and an outer surface (in a radial direction). The term "deflection volume" as described herein may refer to a volume that has a surface that is closer to an arcing zone and a surface that is - in a longitudinal direction - further away from the arcing zone.
According to some embodiments, which can be combined with other embodiments described herein, the deflection volume may be arranged within an inner volume of the exhaust zone. This means that the surface of the deflection volume has a radial distance from the longitudinal axis of the quenching chamber substantially equal to or smaller than a radial extension of the exhaust zone. Arranging the deflection volume within an inner volume of the exhaust zone provides the advantage that the deflection of the gas flow and as a result thereof, the cooling of the gas on its way to the exhaust tank can occur without the necessity of increasing the size of the quenching chamber in a radial direction. In addition, the necessity of using bigger exhaust tanks for decreasing the electric field in the exhaust can be avoided. Using bigger exhaust tanks is theoretically possible but is not a feasible option in view of the costs thereof. The present inventors found out that by arranging one or more deflection volumes in series within the inner volume of an exhaust zone leads to an efficient cooling of hot insulating gases and provides a feasible, space saving, and therefore cost effective solution for significantly transferring energy from the hot gases to surface walls, thereby leading to lower gas temperatures in the exhaust tank. In principle, the proposed flow arrangement allows to put several of these deflection volumes in series along a longitudinal axis of the quenching chamber which can strongly enhance the aforementioned beneficial effects that already occur by using one deflection volume. The present inventors particularly focused on removing heat from the hot gas exhausted from the arcing zone in order to avoid dielectric breakdown from the exhaust (at high voltage) to the tank walls (grounded). Such dielectric breakdown may occur after the arc is extinguished and voltage rises across the circuit breaker.
As indicated above, the deflection volume may be enclosed by a deflection housing having a plurality of openings. Alternatively, the deflection housing may have one opening. These openings allow the hot insulating gases to pass through the deflection volume. The deflection housing may further have at least two housing walls. For instance, the deflection housing may include at least two substantially radial walls. In addition, the deflection housing may further have at least one substantially axial wall. Some of these housing walls may have openings while others do not have openings. "Substantially radial(ly)" as described herein may refer to a direction extending in a direction that is perpendicular (e.g. extending perpendicularly) to a longitudinal axis or that has an angle of less than 45°, additionally or alternatively an angle of less than 15°, additionally or alternatively an angle of more than 0.01° to a direction that is perpendicular to a longitudinal axis. "Substantially axial(ly)" as described herein may refer to a direction that is parallel to a longitudinal axis or that has a deviation of less than 45°, additionally or alternatively less than 15°, additionally or alternatively more than 0.01° to a direction that is parallel to a longitudinal axis.
According to some embodiments, which can be combined with other embodiments described herein, the deflection housing may include at least two substantially radial walls having no openings. In this particular case, the deflection housing may additionally include at least one substantially axial wall having at least two openings. Alternatively, the deflection housing may include at least two substantially radial walls wherein at least one of the substantially radial walls has at least one opening. For instance, the deflection housing may include two substantially radial walls, each having at least one opening and may further have no additional substantially axial wall. Alternatively, the deflection housing may include two substantially radial walls, wherein only one of the substantially radial walls has at least one opening while the other substantially radial wall has no openings. In this particular case, the deflection housing may additionally include one substantially axial wall having at least one opening, or may include two substantially axial walls, each having at least one opening.
According to some embodiments, which can be combined with other embodiments described herein, the deflection volume may be configured to both axially and radially deflect the insulating gas before entering the exhaust tank. In other words, some walls of the deflection housing may interact with the plurality of openings thereof such that the insulating gas is both axially and radially deflected before entering the exhaust tank.
According to some embodiments, which can be combined with other embodiments described herein, a first substantially radial wall and a second substantially radial wall of the deflection housing may be positioned opposite to each other at a minimal distance in a range of 15 mm to 60 mm, typically 20 mm to 45 mm, and more typically 25 mm to 35 mm. According to some embodiments, which can be combined with other embodiments described herein, a first substantially radial wall and a second substantially radial wall of the deflection housing may be positioned opposite to each other at a maximum distance in a range of 200 mm to 300 mm, typically 220 mm to 280 mm, and more typically 240 mm to 260 mm.
According to some embodiments, which can be combined with other embodiments described herein, the deflection housing may have a plurality of openings. A shape of each of the plurality of openings within the deflection housing may be circular, polygonal, or irregular.
According to some embodiments, which can be combined with other embodiments described herein, a maximum width of the plurality of openings may be in a range of 1 mm and 100 mm, typically 3 mm to 80 mm, and more typically 5 mm to 60 mm.
According to some embodiments, which can be combined with other embodiments described herein, a minimum width of the plurality of openings may be in a range of 1 mm and 10 mm, typically 2 mm to 8 mm, and more typically 3 mm to 5 mm.
According to some embodiments, which can be combined with other embodiments described herein, a combined area of first openings may be 1850 mm², a combined area of second opening may be 3800 mm², a combined area of third openings may be more than 4000 mm². First opening as referred to herein may be openings that fluidly connect an exhaust zone with a first deflection volume. Second openings as referred to herein, may be openings that fluidly connect a first deflection volume with a second deflection volume or with an exhaust tank. Third openings as referred to herein may be openings that fluidly connect a second deflection volume with a third deflection volume or with an exhaust tank.
According to some embodiments, which can be combined with other embodiments described herein, the plurality of openings may be positioned in the deflection housing, typically in a wall of the deflection housing, following a random pattern or a regular pattern. A regular pattern may for example be a pattern that is regular in one direction, such as for example a circumferential direction or a longitudinal direction. A regular pattern may for example be a pattern that is regular in two directions, such as e.g. a circumferential and a longitudinal direction.
According to some embodiments, which can be combined with other embodiments described herein, the plurality of openings in the deflection housing may comprise a total number of more than 2, more than 4, more than 8, additionally or alternatively, less than 100, less than 50, or less than 20 openings. The plurality of openings may comprise a total number of 2 to 100 openings, typically 4 to 60 openings, more typically 6 to 20 openings.
According to some embodiments, which can be combined with other embodiments described herein, the plurality of openings may be spaced apart by a distance in a range of 1 mm to 200 mm, typically 5 mm to 150 mm, and more typically 10 mm to 100 mm.
According to some embodiments, which can be combined with other embodiments described herein, the plurality of openings may be arranged offset with respect to one another. For instance, arranging the plurality of openings with an offset may refer to first openings that fluidly connect an exhaust zone with the deflection volume via a first deflection housing wall, said first openings being offset from second openings that fluidly connect the deflection volume with the exhaust zone via a second deflection housing wall. As a result thereof, the insulating gas cannot flow directly through the deflection volume into the exhaust tank without impinging a housing wall. This guarantees one or more impinging effect(s) of the gas flow resulting in a heat transfer to the wall, thereby decreasing the temperature of the insulating gases. In other words, offsetting first and the second openings to one another may beneficially increase the number of impinging events occurring when gas flow on housing walls of the deflection volume. Accordingly, offsetting the first and the second openings to one another may improve the cooling effect for cooling hot insulating gases.
According to some embodiments, which can be combined with other embodiments described herein, the at least one deflection volume may be configured to deflect the hot insulating gases to be dissipated along at least one axially extending volume with a smaller radial extension than the exhaust zone. A deflection volume may have a distance between an inner surface and an outer surface of the deflection volume that is smaller than a distance between a surface of the deflection volume that is closer to an arcing zone and a surface of the deflection volume that is further away from the arcing zone in a longitudinal direction. The relation between the aforementioned distances may be vice versa. In particular, a deflection volume may have a distance between an inner surface and an outer surface of the deflection volume that is greater than a distance between a surface of the deflection volume that is closer to an arcing zone and a surface of the deflection volume that is further away from the arcing zone in a longitudinal direction.
According to some embodiments, which can be combined with other embodiments described herein, two or more deflection volumes may be arranged in series within the exhaust zone along the longitudinal axis of the quenching chamber. Typically, two to ten, more typically two to five deflection volumes may be arranged in series within the exhaust zone along the longitudinal axis of the quenching chamber. Arranging two or more deflection volumes in series along the longitudinal axis of the quenching chamber can significantly enhance the energy absorbed by wall surfaces, resulting in lower gas temperatures in the exhaust. The present inventors realized that for the ongoing development of SF₆ free high voltage circuit breakers, gas mixing is not sufficient to cool the hot plasma from the arc. It has been found out that by using two or more (most typically two to five) deflection volumes, the heat transfer coefficient is nearly an order of magnitude higher as compared to tangential flow. As such, arranging two or more deflection volumes in series provides an efficient way to lower gas temperatures in the exhaust while at the same time minimizing the additional space required for provoking as many impinging events as possible, thereby decreasing the overall costs of the cooling procedure.
According to some embodiments, which can be combined with other embodiments described herein, the two or more deflection volumes arranged in series within the exhaust zone along the longitudinal axis of the quenching chamber are spaced from each other by a distance in a range of 10 mm to 500 mm, typically 20 mm to 350 mm, and more typically 50 mm to 250 mm. As used herein, a distance between two deflection volumes is defined as the distance between a first radial housing wall of a first deflection volume and a second radial wall of a second deflection volume, whereby the first and second radial walls are arranged along an outer wall of exhaust zone or along a longitudinal axis of the exhaust zone without any deflection volume there between.
According to some embodiments, which can be combined with other embodiments described herein, the two or more deflection volumes have the shape of a cylinder with a base area A1 and a height HI, wherein A1 is in a range of 300 mm² and 100000 mm², typically 400 mm² to 70000 mm², and more typically 500 mm² to 30000 mm², and wherein HI is in a range of 30 mm to 250 mm, typically 40 mm to 200 mm, and more typically 50 mm to 150 mm.
According to some embodiments, which can be combined with other embodiments described herein, the two or more deflection volumes have the shape of a hollow cylinder with a base area A2 of the circular ring and a height H2, wherein A2 is in a range of 300 mm² and 100000 mm², typically 400 mm² to 70000 mm², and more typically 500 mm² to 30000 mm², and wherein H2 is in a range of 30 mm to 250 mm, typically 40 mm to 200 mm, and more typically 50 mm to 150 mm.
According to some embodiments, which can be combined with other embodiments described herein, the two or more deflection volumes are arranged such that a first deflection volume has the shape of a cylinder and a second deflection volume has the shape of a hollow cylinder, wherein the outer diameter of the first deflection volume substantially corresponds to the inner diameter of the second deflection volume. Further, a difference between a diameter of the first deflection volume in the shape of a cylinder and a diameter of the second deflection volume in the shape of a hollow cylinder corresponding to the second deflection volume is in a range of 5 mm to 60 mm, typically 8 mm to 30 mm, and more typically 10 mm to 20 mm.
According to some embodiments, which can be combined with other embodiments described herein, a first deflection volume and a second deflection volume may overlap at least partially. The overlap may comprise openings for fluid communication (fluidly connecting) between the first and second deflection volume. The two or more deflection volumes may be configured to direct hot insulating gases to be dissipated with a combination of axial and radial deflections. The axial and radial deflections may substantially be along the longitudinal axis of the circuit breaker within the radial extension of the exhaust zone. For example, hot insulating gas may enter a first deflecting volume in a radial direction; the hot insulating gas may then impinge on an outer wall of the deflecting volume to be deflected in an axial direction away from the arcing zone along a longitudinal extension of the deflecting volume; the hot insulating gas may then be deflected in a radial direction pointing towards the longitudinal axis through openings; the hot insulating gas may then be deflected in an axial direction pointing away from the arcing zone by impinging on a wall of either a second deflecting volume or an exhaust tank.
According to some embodiments, which can be combined with other embodiments described herein, a sequence of deflection volumes may be provided within the radial extension of the exhaust zone of the quenching chamber. As such, the deflection volumes may be provided within the radial extension of the quenching chamber. The sequence of deflection volumes may be provided along an outer wall of the exhaust zone which may also be the outer wall of the quenching chamber. The deflection volumes may share an outer wall with the exhaust zone or may have an outer wall adjacent to the outer wall of the exhaust zone. The sequence of deflection volumes may be provided such that a first deflection volume is adjacent to a second deflection volume or that a first deflection volume and a second deflection volume are spaced apart along an outer wall of the exhaust zone or along the longitudinal axis of the exhaust zone. A sequence of deflection volumes may be provided in an alternating pattern, where a first deflection volume is provided on an outer wall of the exhaust zone and a second deflection volume is provided along a longitudinal axis of the exhaust zone. In an alternating pattern, the deflection volumes may partially overlap and the partial overlap may comprise openings for directing a gas flow from a first deflection volume into a second deflection volume. The openings may direct a gas flow in such a manner that it impinges on a wall of the deflection volume' housing.
According to some embodiments, which can be combined with other embodiments described herein, a method of operating a circuit breaker is provided which may comprise breaking an electric current by the circuit breaker of embodiments described herein.
According to some embodiments, which can be combined with other embodiments described herein, a method for cooling an insulating gas in a circuit breaker is provided, the circuit breaker having at least one quenching chamber filled with the insulating gas. The method may comprise conducting the insulating gas through at least one deflection volume enclosed by a deflection housing. The deflection housing may be arranged within an exhaust zone of the quenching chamber. The exhaust zone may be configured to fluidly connect an arcing zone of the quenching chamber with an exhaust tank. Accordingly, the fluid connection between an arcing zone with an exhaust tank may comprise deflecting the insulating gas through at least one deflection volume arranged in an exhaust zone of the quenching chamber.
FIG. 1 shows a cross-section of a circuit breaker 100 according to embodiments described herein. The circuit breaker may have at least one quenching chamber 102 that extends along a longitudinal axis A. The quenching chamber 102 may contain an arcing zone. While not necessary, the quenching chamber 102 may additionally contain at least two power contact pieces (not shown). At least one of the power contact pieces may be movable. One of the power contact pieces may be provided as a tubular hollow contact. As illustrated in FIG. 1, the exhaust zone 120 has a radial extension r1. Arrows indicate an exemplary flow direction of hot insulating gas from the arcing zone to the exhaust tank 190. The gas flow passes through first openings 142, 144, 146, 148 and second openings 152, 154, 156, 158. A deflection volume 130 is exemplarily depicted that comprises an outer wall 132, an inner wall 138 and a radial wall 134 on a side of the deflection volume 130 that is closer to the arcing zone and a radial wall 136 on a side of the deflection volume that is further away from the arcing zone than radial wall 136.
FIG. 2 exemplarily shows a cross-section of a circuit breaker 200 according to embodiments described herein. The exemplary circuit breaker 200 has a radial extension r2 of an exhaust zone 220 comprising a male contact at a side of an arcing zone. Arrows indicate an exemplary flow of hot insulating gases. The gases flow through openings that connect the exhaust zone 220 with an exhaust tank 290. In the exemplary figure, the gases are directed from a volume of the exhaust zone 220 through openings 242, 244, 246, 248 into a deflection volume 230. The deflection volume 230 has an inner wall 238, an outer wall 232 and side walls 234 and 236, one of the side walls being arranged closer to the arcing zone.
FIG. 3 exemplarily shows a cross-section of a circuit breaker 300 according to embodiments described herein. The circuit breaker 300 may be rotationally symmetric along an axis A or an axis A* or an axis A** (A* out of axis). The exhaust zone 320 may be rotationally symmetric along an axis A or an axis A*. The arrows indicate an exemplary flow of gas from an arcing zone to an exhaust tank 390. The openings 342, 344 connect a volume of the exhaust zone on a side of the arcing zone to a first deflection volume 330. The openings 346, 348 connect the first deflection volume 330 with a second deflection volume 340. The openings 343 connect the second deflection volume 340 with an exhaust tank 390. The openings 342 and 344 are offset from the openings 346 and 348. The openings 346 and 348 are offset from openings 343. The offset of openings may beneficially improve a cooling of gas, as the gas impinges on a wall of a deflection volume.
FIG. 4 exemplarily shows a cross-section of a circuit breaker 400 according to embodiments described herein. The circuit breaker 400 may be rotationally symmetric along an axis A or an axis A* or an axis A** (A* out of axis). The exhaust zone 420 may be rotationally symmetric along an axis A or an axis A*. The arrows indicate an exemplary flow of gas from an arcing zone to an exhaust tank 490 (through a deflection volume). The openings 442, 444 in a radial wall of a deflection volume 430 lead a gas flow to impinge on a second radial wall of the deflection volume 430. The deflection volume has openings 446, 448 in an axial wall of the deflection volume. The openings 446, 448 lead the gas to impinge on a wall of the exhaust zone 420.
FIG. 5 exemplarily shows a cross-section of a circuit breaker 100, 200 according to embodiments described herein. Openings 552, 556 are depicted that connect a deflection volume 530 to an exhaust tank 590. The arrows indicate a flow of hot insulating gases from the deflection volume 530 to the exhaust tank 590. A previous deflection in deflection volume 530 (the gas entering the deflection volume 530) is indicated with dashed arrows. According to some embodiments, which can be combined with other embodiments described herein, openings 552, 556 may be located on opposite sides, rotationally symmetric or randomly with respect to a longitudinal axis.
FIG. 6 shows a cross-section of a circuit breaker 600 according to embodiments described herein. The circuit breaker 600 may have at least one quenching chamber 602 that extends along a longitudinal axis A. The quenching chamber 602 may contain an arcing zone. While not necessary, the quenching chamber 602 may additionally contain at least two power contact pieces (not shown). At least one of the power contact pieces may be movable. One of the power contact pieces may be provided as a tubular hollow contact. As illustrated in FIG. 6, the circuit breaker 600 may have an exhaust zone 620. As shown in FIG. 6, arrows indicate an exemplary flow direction of hot insulating gas from the arcing zone to an exhaust tank 690. The gas flow passes through first openings 632 and 634, second openings 642 and 644, third openings 652 and 654, and fourth openings 662 and 664. The first openings 632, 634 connect a volume of the exhaust zone on a side of the arcing zone to a first deflection volume 670. The second openings 642, 644 connect the first deflection volume 670 with a second deflection volume 680. The third openings 652, 654 connect the second deflection volume 680 with a third deflection volume 690. The fourth openings 662, 664 connect the third deflection volume 690 with the exhaust tank 690. The first openings 632, 634 are offset from the second openings 642 and 644. The offset of openings may beneficially improve a cooling of gas, as the gas impinges on a wall of a deflection volume.
This written description uses examples to disclose the disclosure, including the best mode, and also to enable any person skilled in the art to practice the described subject-matter, including making and using any apparatus or system and performing any incorporated methods.
While various specific embodiments have been disclosed in the foregoing, mutually non-exclusive features of the embodiments described above may be combined with each other. The patentable scope is defined by the claims, and other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims.
While the foregoing is directed to embodiments, other and further embodiments may be devised without departing from the basic scope, and the scope is determined by the claims that follow.

Claims

A circuit breaker, having at least one quenching chamber configured to be filled with an insulating gas, wherein the quenching chamber extends along a longitudinal axis and contains:
(a) an arcing zone, and

(b) an exhaust zone,
wherein the exhaust zone is configured for dissipating hot insulating gas from the arcing zone into an exhaust tank,
wherein at least one deflection volume that is enclosed by a deflection housing is arranged within an inner volume of the exhaust zone and is configured to fluidly connect the arcing zone with the exhaust tank through a plurality of openings within the deflection housing.
The circuit breaker of claim 1, wherein the deflection housing is configured to both axially and radially deflect the insulating gas before entering the exhaust tank.
The circuit breaker of any of the preceding claims, wherein the deflection housing comprises housing walls including at least two substantially radial walls.
The circuit breaker of claim 3, wherein a first substantially radial wall and a second substantially radial wall are positioned opposite to each other at a minimal distance in a range of 15 mm to 60 mm, typically 20 mm to 45 mm, and more typically 25 mm to 35 mm, and wherein a first substantially radial wall and a second substantially radial wall are positioned opposite to each other typically at a maximal distance in a range of 200 mm to 300 mm, typically 220 mm to 280 mm, and more typically 240 mm to 260 mm.
The circuit breaker of any of the previous claims, wherein a shape of each of the plurality openings is circular, polygonal, or irregular.
The circuit breaker of any of the previous claims, wherein a maximum width of the plurality of openings is in a range of 1 mm and 100 mm, typically 3 mm to 80 mm, and more typically 5 mm to 60 mm, and wherein a minimum width of the plurality of openings is typically in a range of 1 mm and 10 mm, typically 2 mm to 8 mm, and more typically 3 mm to 5 mm.
The circuit breaker of any of the previous claims, wherein the plurality of openings are positioned in the deflection housing following a random pattern or a regular pattern.
The circuit breaker of any of the previous claims, wherein the plurality of openings comprises a total number of 2 to 100 openings, typically 4 to 60 openings, more typically 6 to 20 openings.
The circuit breaker of any of the preceding claims, wherein two or more deflection volumes are arranged in series within the tubular hollow contact along the longitudinal axis of the quenching chamber.
The circuit breaker of claim 9, wherein the two or more deflection volumes arranged in series within the tubular hollow contact along the longitudinal axis of the quenching chamber are spaced from each other by a distance in a range of 10 mm to 500 mm, typically 20 mm to 350 mm, and more typically 50 mm to 250 mm.
The circuit breaker of any of claims 9 and 10, wherein the two or more deflection volumes have the shape of a cylinder with a base area A1 and a height HI, wherein A1 is in a range of 300 mm² and 100000 mm², typically 400 mm² to 70000 mm², and more typically 500 mm² to 30000 mm², and wherein HI is in a range of 30 mm to 250 mm, typically 40 mm to 200 mm, and more typically 50 mm to 150 mm.
The circuit breaker of any of claims 9 and 10, wherein the two or more deflection volumes have the shape of a hollow cylinder with a base area A2 of the circular ring and a height H2, wherein A2 is in a range of 300 mm² and 100000 mm², typically 400 mm² to 70000 mm², and more typically 500 mm² to 30000 mm², and wherein H2 is in a range of 30 mm to 250 mm, typically 40 mm to 200 mm, and more typically 50 mm to 150 mm.
The circuit breaker of any of claims 9 and 10, wherein the two or more deflection volumes are arranged such that a first deflection volume has the shape of a cylinder and a second deflection volume has the shape of a hollow cylinder, wherein the outer diameter of the first deflection volume substantially corresponds to the inner diameter of the second deflection volume.
A method of operating a high voltage circuit breaker, the method comprising:
breaking an electric current by the circuit breaker according to any of claims 1 to 13.
A method for cooling an insulating gas in a circuit breaker having at least one quenching chamber filled with the insulating gas, the method comprising:
conducting the insulating gas through at least one deflection volume that is enclosed by a deflection housing and is arranged within an exhaust zone that is configured to fluidly connect an arcing zone with an exhaust tank.