JP5432040B2 - Switchgear - Google Patents

Description

  The present invention relates to a metal-closed switchgear, and more particularly to the structure of the pressure relief part.

As a conventional switchgear having a pressure relief plate, for example, the inside of a casing has a plurality of circuit breaker rooms, a control room, a control equipment room, a common pressure relief room, a current transformer room, a bus room, a vertical bus room, and a cable. There is disclosed a switchgear that is partitioned into a chamber and the like, and a pressure relief plate is provided on the ceiling of the common pressure relief chamber, the cable chamber, and the upper circuit breaker chamber. When an accident occurs in the cable room or upper circuit breaker room, the pressure relief plates on the ceilings of those rooms are opened, and heat compression is performed by an arc generated in the lower circuit breaker room or vertical bus room that does not have a direct pressure release room. The air thus discharged is released to the upper part of the housing via the common release chamber (see, for example, Patent Document 1).
Further, there are disclosed a switchgear in which a partition is erected so as to surround the entire pressure relief plate of the ceiling of the casing, and a switchgear provided with a duct that covers the entire pressure relief of the casing ceiling. This prevents high-temperature gas released from the pressure relief part of the ceiling of the case due to an accident in the busbar room, circuit breaker room, or cable room from flowing into the maintenance space around the switchgear (patented) Reference 2).
As another method, a cooling chamber is provided in communication with the electrical equipment storage chamber, a porous material made of non-combustible solid particulate material is disposed in the cooling chamber, and a gas flow caused by an arc in the storage chamber is ejected into the cooling chamber. In some cases, a method of absorbing the energy of high-temperature gas with a porous material is also disclosed (see Patent Document 3).

Japanese Patent Laid-Open No. 10-322811 (page 4, FIG. 1-2) JP 2007-221878 (second page, FIGS. 1 and 7) JP 2005-528743 A (6th page, Fig. 1-3)

  In the conventional switchgear as shown in Patent Document 1, when an arc occurs due to an internal short circuit accident or the like, the internal pressure of the accident occurrence chamber rises, and the pressure relief plate on the casing ceiling is opened by the pressure, and the internal switchgear The rise in pressure inside the housing is restricted by releasing the high-temperature and high-pressure gas to the outside. Normally, the height of the ceiling of the electrical room in which the switchgear is installed is limited, and the height of the switchgear needs to have a predetermined dimension. There was a problem that the space distance to the ceiling was small, the high-temperature high-pressure gas bounced off the ceiling, and the high-temperature gas circulated into a wide maintenance space around the switchgear.

In addition, in the conventional switchgear as shown in Patent Document 2 where a partition is provided around the pressure relief part of the casing ceiling, the streamline of the high-temperature and high-pressure gas released from the casing ceiling is changed. The purpose is to reduce the influence of hot gas on the maintenance space near the switchgear by lowering the gas temperature with ambient room temperature air by flowing as far as possible, but the fault current is large and the fault duration When a large-scale electric accident such as a long period of time is assumed, the momentum of the high-temperature and high-pressure gas increases, and the high-temperature gas collides with the ceiling and bounces off. Since the behavior of high-pressure gas becomes complicated and it becomes difficult to control high-temperature gas flow lines by partitions, the size of the electrical room where the switchgear is installed (especially the ceiling height)
There is a problem that the construction cost becomes high.

  Further, as shown in another embodiment of Patent Document 2, a ceiling portion is provided on a partition around the pressure release portion of the casing ceiling portion, and a duct shape is formed, and the released gas is guided by the duct. In conventional switchgear that does not release hot gas into the electrical chamber, it is necessary to consider the effect of hot gas on the periphery of the switchgear in the event of an arc accident occurring inside the switchgear, corresponding to the size of the electrical chamber. However, it is necessary to design a duct to be installed in each electrical room where the switchgear is installed, which has the disadvantage of increasing the cost of the entire facility, such as an increase in installation costs for the electrical room, in addition to the duct manufacturing cost. It was.

  Furthermore, in the thing shown in patent document 3, the cooling chamber which absorbs the fluid energy discharged | emitted by filling incombustible porous substances, such as a pumice and Sipolex (brand name), in the exterior of the pressure-release opening of an electrical equipment storage chamber is provided. Although it is provided, a compartment and a cooling chamber for storing the non-combustible porous material are necessary, so that there is a problem in that the size of the electric equipment is increased, leading to an increase in the cost of the entire equipment including the installation work cost.

  The present invention has been made to solve the above-described problems, and it is an object of the present invention to reduce the gas temperature of the hot gas flowing out from the pressure release means provided in the switch gear in the event of an internal arc accident in the switch gear. .

  In the switchgear according to the present invention, the inside of the housing is partitioned into a plurality of compartments, and an opening is provided in the ceiling portion of the housing that communicates with the compartment in which the main circuit components are accommodated. In a switchgear equipped with a pressure release means for releasing the generated high-pressure and high-temperature gas, the pressure release means has a pressure release plate that closes the opening and a heat absorption member fixed to the inside of the housing of the pressure release plate. However, the opening is normally closed by the pressure release plate, and when an accident occurs in the main circuit component, the pressure release plate is opened due to abnormal pressure, and the heat absorbing member is inserted into the gas flow path formed in the opening. The dislocation is performed and the high-temperature gas passes through the endothermic member and is cooled.

  According to the switchgear of the present invention, the pressure release means includes the pressure release plate that closes the opening and the heat absorbing member that is fixed to the inside of the housing of the pressure release plate, and the opening is normally closed by the pressure release plate. When an accident occurs in the main circuit parts, the pressure release plate is opened with abnormal pressure, the heat absorbing member is displaced into the gas flow path formed in the opening, and high-temperature gas passes through the heat absorbing member. In the event of an arc accident inside the housing, the heat absorbing member is exposed to high-temperature gas and melted / evaporated to absorb the heat, and the gas temperature is lowered and discharged outside the housing. Therefore, without the need for special equipment such as screens and exhaust ducts for safely guiding the hot gas, or cooling chambers for absorbing the energy of the hot gas to be ejected, Impact can be reduced and safety Fine reliable, and it can provide a compact switchgear.

It is side surface sectional drawing of the switchgear by Embodiment 1 of this invention. It is a perspective view of the pressure release means part of FIG. It is a conceptual diagram which shows the aspect at the time of the internal arc accident of a switchgear. It is a figure which shows the time-dependent change of an electric current, temperature, and pressure in the simulation experiment of the internal arc accident of a switchgear. It is a figure explaining the time-sequential change of the housing internal pressure rise at the time of the internal arc accident of a switchgear. It is side surface sectional drawing which shows the other structural example of the switchgear of Embodiment 1 of this invention. It is a perspective view of the pressure release means part of the switchgear by Embodiment 2 of this invention. It is a perspective view which shows the other example of the pressure release means part of the switchgear by Embodiment 2 of this invention. It is a perspective view of the pressure release means part of the switchgear by Embodiment 3 of this invention. It is a perspective view which shows the other example of the pressure release means part of the switchgear by Embodiment 3 of this invention.

Embodiment 1 FIG.
1 is a side sectional view of a switchgear according to Embodiment 1 of the present invention. First, the internal structure of the switchgear will be described with reference to FIG.
The interior of the ground metal casing 1 is partitioned into a plurality of compartments. On the left side (front side) of the figure, a circuit breaker compartment 3 in which a drawer type circuit breaker 2 is accommodated is disposed, and the circuit breaker 2 can be pulled out from the front side. On the rear wall of the circuit breaker compartment 3, disconnecting portions 4 a and 4 b of the main circuit are fixedly provided at a predetermined interval in the vertical direction, and can be attached to and detached from a connection terminal protruding from the back surface of the circuit breaker 2. The disconnecting portions 4a and 4b are provided with main circuit terminals 5a and 5b on the back side.
Above the circuit breaker compartment 3 is a control device compartment 6 in which a control instrument (not shown) is accommodated.

Above the rear side of the circuit breaker compartment 3 is a bus compartment 9 in which a three-phase bus 7 is supported by a support insulator 8 and is arranged in the main part of a disconnecting portion 4 a connected to one end of the circuit breaker 2. The circuit terminal 5a and the bus 7 are connected and accommodated by the branch conductor 10.
Behind the bus compartment 9 is a cable compartment 12 in which the load-side cable 11 is accommodated. The main circuit terminal 5b of the disconnecting portion 4b connected to the other end side of the circuit breaker 2 and the cable 11 are connected by a load-side conductor 13, and the current transformer 1 is in the middle of the load-side conductor 13.
4 is provided penetrating. A ground switch 15 is connected to the main circuit terminal 5b via a load-side conductor 13.

A door 16 that is opened and closed by a hinge is provided on the front side of the housing 1, and each of the circuit breaker compartment 3, the control equipment compartment 6, the bus compartment 9, and the cable compartment 12 constitutes an independent chamber.
The circuit breaker compartment 3, the bus compartment 9, and the cable compartment 12, which are the compartments in which the main circuit components are stored, communicate with the top plate of the ceiling of the housing 1, and the openings provided in the top plate of each compartment 1a, 1b, and 1c are provided with a pressure releasing means 17 as described below.

  Note that the internal configuration of the housing 1 illustrated in FIG. 1 is an example, and is not limited to the arrangement configuration illustrated. Usually, it is composed of a compartment for accommodating a drawing device such as a circuit breaker, a bus compartment, a cable compartment and a control device compartment, but there may be no cable compartment, and other configurations may be used. In either case, the pressure release means is provided in a compartment in which main circuit components that may generate high-pressure and high-temperature gas in the event of an accident are stored.

FIG. 2 is a perspective view showing details of the pressure release means 17 of FIG. In addition, although the magnitude | size of the pressure release means 17 provided in each compartment may change with the magnitude | sizes of an opening part, since it is fundamentally the same shape, it demonstrates as the same pressure release means in the following description.
In FIG. 2, the pressure release means 17 includes a pressure release plate 18 that is a portion covering each of the openings 1 a, 1 b, and 1 c, and a heat absorbing member that is fixed to one side of the pressure release plate 18 (a surface on the inner side of the housing 1). It is comprised with the fin 19 which is. The fin 19 is a feature of the present invention.

The pressure relief plate 18 includes a movable portion 18a to which the fins 19 are fixed, a fixing portion 18b joined to the top plate of the housing 1 by means of a fastening member such as a bolt or welding or adhesion, and a part of the slit 18 or the like. And a bent portion 18c which is weakened and easily bent. The fixed portion 18b is attached to the housing 1, and when the internal pressure of the housing 1 increases, the movable portion 18a bends outwardly with respect to the fixed portion 18b in a “<” shape around the bent portion 18c. Further, the structure is plastically deformed.
The mounting hole 18d is a hole used when the fixing portion 18b is fixed to the top plate of the housing 1 with, for example, bolts or rivets. When the fixing portion 18b is fixed to the top plate of the housing 1 by welding or bonding, The mounting hole 18d is not necessary.

  The bent portion 18c is flat as shown in the figure during normal operation (although the operation will be described later). When an accident occurs inside the switchgear housing 1, this portion is the top plate of FIG. It is bent into a state as indicated by a broken line in the part. That is, the function is the same as that of a general hinge, and of course, the hinge may be attached. However, since the pressure release means 17 functions only when an accident occurs, it is not necessary to consider the reuse of the members so much. From the viewpoint of cost reduction, an example adopting a structure in which a slit is inserted and plastically deformed is illustrated. doing.

As shown in FIG. 2, the fin 19 is made of a plurality of thin metal plates having a substantially circular shape of a circle, and is perpendicular to the surface of the pressure release plate 18 and in the direction of the folding axis of the folding portion 18 c. Are arranged side by side and are erected on the pressure release plate 18. If the expected cooling effect and the space for the installation part can be ensured, it may be a semicircular shape of 1/2 circle, or it may be a fan shape with a sharper angle than 1/4 circle.
In any case, when the pressure release means 17 operates and the pressure release plate 18 opens outward from the bent portion 18c, the shape is set so as not to interfere with the openings 1a to 1c, and the operating state ( FIG.
In a state indicated by a broken line in FIG. 2, the internal gas can pass through the fin gap.

Next, the appearance at the time of an arc accident inside the switchgear casing will be described with reference to FIG.
When an electrical accident occurs in the main circuit inside the switchgear, an arc is generated in that part, and the part is in a plasma state of about 1 to 20,000 degrees C. Therefore, the air around the arc in the compartment where the accident occurred suddenly When heated, the pressure in the compartment rises rapidly. This state is the “compressed phase” shown in FIG. At this time, for example, the release pressure of the pressure release means 17 is designed so as to limit the pressure increase in the housing so as not to damage or destroy the front door 16 or the like. In about 10 to several milliseconds, the pressure release means 17 of the compartment opens.

When the pressure release means 17 is opened, a high-pressure and high-temperature gas in which air heated and compressed in the compartment is mixed with steam such as a metal melted by an arc, a coating film, or an insulator is formed in the opening of the housing 1. From the pressure relief means to the outside of the switchgear. This state is the “expanded phase”.
After that, the ejected high-pressure and high-temperature gas diffuses into the surrounding air, and this state is the “radiation phase”. At this time, most of the air in the compartment is released at a time, and therefore the pressure suddenly drops in the compartment. This time is about 10 to several tens of milliseconds.
It is known that the air temperature in the compartment rises slightly behind the pressure rise.

Fig. 4 shows a paper (ED) presented at the Joint Discharge, Stationary, Opening and Shutting Protection Research Group of the Institute of Electrical Engineers of Japan
-08-79) is a graph showing changes over time in current, housing pressure and housing air temperature in an experimental example simulating a relatively small-scale accident with a switchgear model.
Since the air around the arc generated by the accident current is instantaneously heated and suddenly expands after the start of energization of the accident current, the pressure inside the enclosure is propagated to the pressure release means at the speed of sound and released. The pressure means is released in about 5 milliseconds by the first impact pressure, and then reaches the maximum value of the pressure increase in about 7 milliseconds after the start of energization. After about 26 milliseconds after the start of energization, the high-pressure gas inside the enclosure is released. Therefore, it can be seen that the pressure increase value becomes 0 and then becomes a slight negative pressure.
The air temperature in the housing gradually increases after the accident current energization is started, is about 25 milliseconds after the release of the pressure release means, and reaches a maximum temperature in about 30 milliseconds after the energization is started. Of course, there is a delay in the response time of the instrument in measuring the gas temperature, so the actual temperature rise time is slightly earlier than the above time, but even if the time delay is taken into account, it is slightly behind the pressure rise time. Is proved from the theoretical calculation in this paper.

When an electrical accident occurs, the current status of abnormal current passing or abnormal voltage in the main circuit is detected by a current transformer or instrument transformer, and the protective relay operates. Since the relevant circuit breaker of the section is opened and the fault circuit is disconnected, the duration of the fault is the sum of the operating time of the protection relay and the arc time when the circuit breaker is cut off.
Although it depends on the type of electrical accidents such as ground faults and short circuit accidents, and the operation time setting of protection relays through protection coordination, it is generally in the range of about a few tens of milliseconds to about 1 second. Also in the switch gear standard IEC62271-200, 0.1 seconds, 0.5 seconds, and 1.0 seconds are selected as test conditions, and the maximum is assumed to last about 1.0 seconds. Yes. Therefore, an arc generated by an electrical accident may be continuously generated during the accident duration unless self-extinguishing is performed.

For this reason, the arc continues inside the switchgear even in the process of diffusion cooling to the surrounding space in the “radiation phase” after the high pressure gas is released in the “expansion phase” once the release plate is opened, and the compartment Continue to burn and melt the metals and insulators inside. As a result, the air that remains slightly and the air taken in from the gaps in the compartments and the housing due to the negative pressure in the compartment are further heated and released from the pressure relief outlet along with the combustion and molten steam. The state to continue continues.
The released gas temperature at this time may be several thousand degrees C depending on the scale of the accident and the duration of the accident, and this state is the “thermal phase”. When the above-described failure removal time is long, the “thermal phase” state continues for a long time.

  FIG. 5 is a diagram showing the time course of the “compression phase”, “expansion phase”, “radiation phase”, and “thermal phase” in the above description and the situation of the internal pressure P of the enclosure. It can be seen that the thermal phase continues for a long time even after the pressure P decreases. Therefore, it is very important in maintenance of the switchgear to efficiently cool the released gas until the “thermal phase” duration ends.

Next, the operation and action of the pressure release plate 18 and the fin 19 of the pressure release means 17 shown in FIG. 2 according to the present embodiment when an accident occurs will be described.
During normal operation, the pressure relief plate 18 is a switch for the openings 1a, 1b, 1c provided in the main circuit compartment of the housing 1, that is, the ceiling top plates of the circuit breaker compartment 3, the bus compartment 9 and the cable compartment 12. It is closed so that falling objects and dust from above the gear do not enter the inside of the housing 1.

Here, for example, when an electrical accident occurs inside the circuit breaker compartment 3, an arc is generated between the phases of the main circuit or between the charged part of the main circuit and the ground metal, and explosive inside the circuit breaker compartment 3. As a result, a pressure rise occurs, and a “compressed phase” state is first obtained. The movable part 18a of the pressure release plate 18 of the pressure release means 17 provided on the ceiling part of the switchgear due to the shocking pressure rise.
However, it is integral with the fin 19 fixed to the inner side and bends approximately 90 degrees outward from the bent portion 18c, and the opening 1a on the ceiling of the circuit breaker compartment 3 is opened. Since the fin 19 moves simultaneously with the opening operation of the movable portion 18a, the fin 19 is transferred into the gas flow path formed in the opening 1a, and then the high-pressure and high-temperature gas is ejected through the fin 19. It becomes the state of the “expanded phase”.
The high-pressure and high-temperature gas ejected from the opening 1a in the “radiation phase” and “thermal phase” thereafter passes through the gaps of the fins 19 and melts the surface of the fins 19 at that time. At this time, the heat of melting at the time of melting is taken away, so that the high-temperature gas is cooled and discharged to the surrounding space.

  When an electrical accident occurs inside the busbar compartment 9 and the cable compartment 12, as in the case of the circuit breaker compartment 3, the pressure release means 17 provided corresponding to each compartment is operated, and the fins 19 are the same. To work.

  As described above, by providing the fin 19 as the heat absorbing member in the pressure release means 17, the temperature of the high-pressure and high-temperature gas generated in the switchgear internal arc accident is lowered by the fin 19 and discharged to the outside of the housing. Therefore, the hot gas can be prevented from entering the maintenance space around the switchgear. As a result, as described in the background art section, the switchgear ceiling screen for changing the streamline of the hot gas, the duct that traps the hot gas and discards it outside the electric room, or the hot gas that is ejected from the pressure release port In order to absorb this energy, special equipment such as a cooling chamber provided outside the pressure release port of the switch gear is not required. For this reason, no additional construction is required on site, and the production quality at the factory can be secured as it is, so that a switch gear with excellent reliability can be provided in a small size. In addition, the cost for construction such as transportation and installation can be reduced, and the electrical room for storing the switchgear can be made smaller.

Next, another example of the structure for attaching the pressure release means 17 to the housing 1 will be described.
FIG. 6 shows a configuration substantially the same as that of the switch gear shown in FIG. 1, but the attachment portion of the pressure release means 17 is a fin fixed to the pressure release means 17 in the openings 1 a to 1 c of the ceiling portion of the housing 1. A box part 20 in which 19 is accommodated is provided, and a pressure release plate 18 is attached to the upper surface of the box part 20 so that the pressure release means 17 part is unitized. The hot gas cooling effect at the time of the accident is the same as in FIG.
According to this configuration, it is not necessary to confirm the insulation distance between the main circuit inside the housing and the fin 19 each time depending on the form of the switchgear, and further, the reliability is improved by the standardization of the design, and the parts are standardized. There are advantages such as productivity improvement in module production.

  As described above, according to the switchgear of Embodiment 1, the inside of the housing is partitioned into a plurality of compartments, and the opening is provided in the ceiling portion of the housing that communicates with the compartment in which the main circuit component is accommodated. The switchgear is provided with a pressure release means for releasing high-pressure and high-temperature gas generated by an accident of the main circuit parts at the part, and the pressure release means is disposed on the inside of the housing of the pressure release plate and the pressure release plate that closes the opening. In the normal state, the opening is closed by the pressure release plate. When an accident occurs in the main circuit component, the pressure release plate is opened by the abnormal pressure and formed in the opening. Since the heat absorbing member is dislocated into the gas flow path, and the high temperature gas passes through the heat absorbing member and is cooled, the heat absorbing member is exposed to the high temperature gas in the event of an arc inside the housing and is dissolved and evaporated. Heat absorbed by As the temperature of the gas is lowered and discharged to the outside of the housing, special equipment such as a screen for safely guiding the hot gas, an exhaust duct, or a cooling chamber for absorbing the energy of the hot gas to be ejected is provided. It is possible to reduce the influence of the high-temperature gas around the switchgear without necessity, and to provide a switchgear that is highly safe and reliable and that is compact.

  Further, since the heat absorbing member is composed of a plurality of metal thin plate fins erected substantially perpendicular to the pressure release plate, in addition to the above effects, the heat of the high temperature gas generated at the time of the accident can be effectively absorbed. .

Embodiment 2. FIG.
7 and 8 are perspective views showing the configuration of the pressure release means portion of the switchgear according to the second embodiment, which corresponds to FIG. 2 of the first embodiment. Since the main body configuration of the switchgear is the same as that of the first embodiment shown in FIG. 1 (or FIG. 6), illustration and description thereof are omitted. Below, it demonstrates centering on difference with FIG. 2 that are the same as those in FIG.
The pressure release means of the second embodiment is similar to the fin 19 described with reference to FIG. 2, but is provided with an obstacle on the surface of the fin.

First, FIG. 7 will be described. As shown in the figure, the pressure release means 21 is composed of a pressure release plate 18 and fins 22 which are heat absorbing members fixed to the pressure release plate 18, and a large number of through holes 22 a are formed on the surface of each fin 22. It is characterized in that it is provided. The outer shape is the fin 19 in FIG.
It is the same.
In order to peel off the boundary layer film formed between the surface of the fin 22 and the hot gas fluid by partially generating a turbulent flow when the hot gas passes through the gap between the fins 22 by the through hole 22a, There is an effect of further enhancing the cooling effect of the high-temperature gas.

  In FIG. 7, the fin 22 provided with a plurality of through holes 22a has been described. However, instead of the through holes 22a, a plurality of protrusions may be formed by stamping or the like. Processing such as roughening the surface roughness of may be performed. Furthermore, if these are used in combination, the cooling effect can be expected to be further enhanced.

FIG. 8 is a perspective view showing another example of the pressure release means. As shown in the figure, the pressure release means 23 is formed by corrugating the surface of the fin 24 fixed to the pressure release plate 18. In the figure, the waveform is formed in a direction parallel to the surface of the pressure release plate 18, but may be a waveform perpendicular to the surface of the pressure release plate 18.
According to this configuration, since the surface area of the fin 24 is increased, the contact area with the fin 24 when the high-temperature gas passes through the gap between the fins 24 is increased, the endothermic action is enhanced, and the cooling effect of the high-temperature gas is enhanced. be able to.
Note that the corrugated fins 24 may be combined with a process of providing a plurality of through holes or a plurality of protrusions as formed in the fins 22 of FIG. Furthermore, if the process of roughening the surface roughness of the fins 21 is performed, the cooling effect can be further enhanced.

  As described above, according to the switchgear according to the second embodiment, the heat absorbing member attached to the inside of the pressure release plate of the pressure release means of the switchgear is a plurality of thin metal plate fins erected vertically to the pressure release plate. Each fin has a plurality of through-holes or protrusions, so when the hot gas passes through the gaps between the fins, a partial turbulence occurs and the fin surface and the hot gas fluid Since the boundary layer film formed therebetween is peeled, in addition to the effect of the first embodiment, the cooling effect of the high temperature gas can be further enhanced.

  In addition, since each fin provided inside the pressure relief plate is formed in a corrugated shape, the endothermic effect is enhanced by increasing the contact area with the fin when the high-temperature gas passes through the gap between the fins, and Similarly, the cooling effect of the high temperature gas can be further enhanced.

Embodiment 3 FIG.
FIGS. 9 and 10 are perspective views showing the configuration of the pressure release means portion of the switch gear according to the third embodiment, which corresponds to FIG. 2 of the first embodiment. Since the main body configuration of the switchgear is the same as that of the first embodiment shown in FIG. 1 (or FIG. 6), illustration and description thereof are omitted. Below, it demonstrates centering on difference with FIG. 2 that are the same as those in FIG.
The pressure release means of the third embodiment is not a plurality of fins instead of the fins 19 described in FIG. 2, but a member that allows the internal gas to pass through the opening when the pressure release plate operates as a heat absorbing member. Adopted.

First, FIG. 9 will be described. As shown in the figure, the pressure release means 25 is obtained by fixing a metal mesh 26 as a heat absorbing member to the back surface (side facing the inside of the housing 1) of the movable portion 18 a of the pressure release plate 18. The fixing position is in the vicinity of the bent portion 18c, and is erected vertically to the pressure release plate 18 in a direction along the bent portion 18c.
The metal mesh 26 has a shape and a size that substantially cover the opening 1a (or 1b, 1c) of the housing 1, and is fixed to the mounting frame 27 by a joining means such as welding, fitting, crimping, or adhesion, The necessary strength and form are secured. When the pressure release means 25 operates and the pressure release plate 18 is bent and opened from the bent portion 18c with the pressure release means 25 incorporated in the housing 1, the wire mesh 26 is also rotated together. It covers the opening 1a and is configured to displace into the gas flow path formed in the opening 1a.

With such a configuration, in the event of an internal accident, the pressure release plate 18 is opened by an instantaneous pressure increase immediately after the occurrence of the accident and opens almost at a right angle, and the opening is covered with the wire mesh 26. When the gas is ejected from the part, it passes through the metal mesh 26 and is absorbed by the surface of the metal mesh 26 to cool the high temperature gas.
Note that the wire net 26 may be an expanded metal or a metal net-like member.

Next, FIG. 10 shows another example of the pressure release means. The pressure release means 28 is obtained by fixing a metal porous plate 29 in which a plurality of pores 29a are formed as a heat absorbing member, instead of the wire mesh 26 of FIG. As the perforated plate 29, for example, a well-known punching metal is suitable, and the shape of the pore is not limited to a circle but may be any shape.
As in FIG. 9, the porous plate 29 has a shape and size that substantially covers the opening of the housing 1, and is secured to the support frame 30 by a joining means such as welding or adhesion to ensure the necessary strength and form. ing. The fixing position is the same as that of the wire mesh 26 of FIG. 9, and is erected in a substantially vertical state on the back surface of the movable portion 18a.
In the event of an accident, as in FIG. 9, the pressure release plate 18 is opened by an instantaneous pressure increase immediately after the occurrence of the accident and opens almost at a right angle, so that the porous plate 29 covers the opening. When it is ejected from, it passes through the pores 29a of the perforated plate 29 and is absorbed by the surface of the perforated plate 29 to be cooled.

In each of the pressure release means of the first to third embodiments described above, the heat absorbing member provided inside the pressure release plate, that is, the fin 19 of FIG. 2, the fin 22 of FIG. 7, the fin 24 of FIG. 8, and FIG. The metal mesh 26 and the perforated plate 29 shown in FIG. 10 may be made of a porous sintered metal or a foamed alloy.
Since the porous sintered metal has a large contact area with the high temperature gas and is excellent in high temperature resistance, it is effective for enhancing the cooling effect of the high temperature gas.
Since the foamed alloy has a high porosity in the metal porous body, the contact area with the high temperature gas becomes larger, which is effective in enhancing the cooling effect of the high temperature gas.

Further, the surface of each endothermic member may be coated with a metal hydroxide compound such as magnesium hydroxide, a material that generates a lot of water molecules during combustion, or a film of a polymer material that contains a lot of water molecules. good.
By taking these measures, there is an effect of maintaining the cooling effect of the hot gas for a long time.

As described above, according to the switchgear of the third embodiment, the heat absorption member attached to the inside of the pressure release plate of the pressure release means of the switchgear is a metal mesh member erected substantially perpendicular to the pressure release plate,
Or, because it is composed of a metal perforated plate having a plurality of pores, at the time of an internal accident, the pressure release plate opens by an instantaneous pressure increase immediately after the accident occurs and opens at a substantially right angle, and the opening is formed by a mesh member or perforated plate. The high temperature gas that is covered and subsequently ejected passes through the mesh member or the perforated plate and is absorbed by the surface of the mesh member or the perforated plate to cool the high temperature gas. Can be obtained at

  In addition, since the endothermic member is formed of a porous sintered alloy, a high temperature released from the pressure release means at the time of an accident by a porous sintered alloy having a large contact area with a high temperature gas and excellent high temperature resistance. The gas cooling effect can be further enhanced.

  Moreover, since the endothermic member is formed of the foam metal, the contact area with the high-temperature gas is increased by the foam metal having a large porosity, and the cooling effect of the high-temperature gas can be further enhanced.

  In addition, since the surface of the endothermic member is coated with a metal hydroxide compound, the cooling effect of the high temperature gas can be maintained for a long time, so that the failure duration is long and the thermal phase in which the high temperature gas is released continues for a long time. In particular, a cooling effect can be expected.

  Furthermore, since the surface of the endothermic member is coated with a polymer material containing a large amount of water molecules, the cooling effect of the high temperature gas can be maintained for a long time, and the same effect as described above can be obtained.

DESCRIPTION OF SYMBOLS 1 Housing | casing 1a-1c Opening part 2 Circuit breaker 3 Circuit breaker compartment 4a, 4b Disconnection part 5a, 5b Main circuit terminal 6 Control equipment compartment 7 Busbar 8 Supporting insulator 9 Busbar compartment 10 Branch conductor 11 Cable 12 Cable compartment 13 Load side conductor DESCRIPTION OF SYMBOLS 14 Current transformer 15 Ground switch 16 Door 17, 21, 23, 25, 28 Pressure release means 18 Pressure release plate 18a Movable part 18b Fixed part 18c Bending part 18d Mounting hole 19, 22, 24 Fin (heat absorption member)
20 Box part 22a Through-hole 26 Wire mesh (endothermic member) 27 Mounting frame 29 Perforated plate (endothermic member) 29a Pore 30 Support frame.

Claims (9)

The inside of the housing is partitioned into a plurality of compartments, and an opening is provided in the ceiling portion of the housing that communicates with the compartment in which the main circuit component is accommodated, and the high voltage generated by the accident of the main circuit component in the opening. In a switchgear provided with a pressure release means for releasing a high-temperature gas,
The pressure release means includes a pressure release plate that closes the opening, and a heat absorbing member fixed to the inside of the casing of the pressure release plate,
Normally, the opening is closed by the pressure release plate. When an accident occurs in the main circuit component, the pressure release plate is opened by an abnormal pressure and into the gas flow path formed in the opening. The switchgear is configured so that the heat absorbing member is dislocated and the high-temperature gas passes through the heat absorbing member and is cooled. The switchgear according to claim 1, wherein
The switchgear is characterized in that the heat-absorbing member is composed of a plurality of thin metal-plate fins erected substantially perpendicularly to the pressure release plate. The switchgear according to claim 2,
Each of the fins is provided with a plurality of through holes or protrusions. The switchgear according to claim 2,
Each said fin is formed in the waveform, The switchgear characterized by the above-mentioned. The switchgear according to claim 1, wherein
The switchgear is characterized in that the heat-absorbing member is constituted by a metal net-like member erected substantially perpendicularly to the pressure release plate or a metal perforated plate having a plurality of pores. In the switchgear according to any one of claims 1 to 5,
The switchgear is characterized in that the heat absorbing member is formed of a porous sintered alloy. In the switchgear according to any one of claims 1 to 5,
The switchgear is characterized in that the heat absorbing member is made of foam metal. In the switchgear according to any one of claims 1 to 5,
A switchgear, wherein a surface of the heat absorbing member is coated with a metal hydroxide compound. In the switchgear according to any one of claims 1 to 5,
The switchgear is characterized in that the surface of the heat absorbing member is coated with a polymer material containing a large amount of water molecules.

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