Switchboard structure

Abstract

The present invention secures the safety of surrounding workers by safely discharging, with a simple structure, hot gas from a switchboard, the hot gas being generated by a short-circuit fault, or the like. The inside of a housing 1 of the switchboard is partitioned into a plurality of compartments 12-14. A pressure release plate 16 that opens and closes in accordance with pressure changes in the compartments 12-14 is provided at an opening of each compartment 12-14, and the structure comprises a pressure relief chamber 18 communicating with the openings and a pair of front and rear pressure relief frames 19 arranged in the pressure relief chamber 18. An opening 19d is formed in a side surface part 19b of each pressure relief frame 19, a reinforcing plate 20 in which a vent hole group 25 is formed is installed in the front-side pressure relief frame 19, and a louver plate 21 is installed in the rear-side pressure relief frame 19. The reinforcing plate 20 is provided with a pair of double-opening pressure release plates 22 with the vent hole group 25 sandwiched therebetween, and a single-opening pressure release plate 23 is supported on a rear portion of the louver plate 21.

Description

Structure of Switchboard

[0009]

[0001] The present invention relates to a housing structure of a switchboard that discharges (emits) hot gas generated by a short - circuit accident or the like.

[0002] In a closed - type switchboard or the like, a structure is adopted in which the inside of a grounded metal box is partitioned into a plurality of compartments, and main circuit components such as circuit breakers, busbars, and connecting conductors are housed in each compartment.

[0003] When an internal arc accident accompanied by the generation of an arc due to a short - circuit accident or the like occurs in each compartment, the internal pressure of the compartment rises, and there is a risk that arc gas may be discharged from the housing, door, monitoring window, etc.

[0004] Also, when an internal arc accident occurs in the compartment, the components housed in the compartment may generate high - temperature decomposition products that are gasified or vaporized, and there is also a risk of being discharged outside the compartment.

[0005] Therefore, as shown in Patent Document 1, for a closed - type switchboard such as a switchgear, a structure for reducing the released gas pressure has been proposed in order to reduce the momentum of the high - temperature decomposition products released from the compartment to the outside.

[0006] Japanese Patent No. 5804223

[0007] Publication No. 2020 - 501166 of the Technical Report of the Japan Institute of Invention and Innovation

[0008] When a switchgear having an internal arc rating (IAC) is housed, a structure must be provided that can ensure the safety of workers even when a short - circuit occurs. In particular, the released gas (hot gas) containing high - temperature decomposition products during a short - circuit is generally discharged to the upper part of the switchboard housing, but it is necessary to consider the extremely powerful discharge momentum such as the rebound of the ceiling.

[0009] In this case, the structure of Patent Document 1, as shown in Figure 6(a), is provided with ducts 4 that communicate with each compartment of the housing 1. With this structure, in the event of an internal arc accident, the pressure relief plate 5 at the top of the compartment opens, and the discharged hot gas is guided into a shared pressure relief chamber 2. The pressure relief frame 3 disperses the force, and the attenuated hot gas is released to the top of the housing 1. However, as shown by the hot gas G3 in Figure 6(b), since it is discharged in the vertical direction, it tends to accumulate in the corners of the ceiling 9 and the rear wall 10, which is hardly safe.

[0010] Therefore, Non-Patent Document 1 employs a structure in which a pair of front and rear louver plates 8 are attached to the upper outlet of the pressure relief frame 3, as shown in Figure 7(a), thereby discharging the hot gas to the front (front side) rather than the rear where the hot gas tends to accumulate.

[0011] Although this structure yielded some results, when vortices were generated in the flow of hot gas, as shown in Figure 7(b) for hot gas G2, there was a risk that it could reach a location where workers might be present. Under certain conditions, this could compromise worker safety, and the expected effects could not be achieved.

[0012] Furthermore, there are often concerns about the presence of an opening above the switchgear inside the enclosure 1, and a structure is desired that allows for the control of hot gas discharge and also allows the opening to be closed.

[0013] This invention was made to address such conventional demands, and aims to solve the problem of safely discharging hot gases from a power distribution panel caused by short-circuit accidents, etc., with a simple structure, thereby ensuring the safety of surrounding workers.

[0014] (1) The present invention relates to a structure for a power distribution panel comprising a housing divided into a plurality of compartments, for discharging hot gas from within the compartments, comprising: a pressure relief plate provided at the opening of one of the compartments and opening and closing in accordance with changes in pressure within the compartments; a pressure relief chamber communicating with the opening; a pressure relief frame disposed within the pressure relief chamber; a grid-shaped reinforcing plate installed on one side of the pressure relief frame and having ventilation holes formed therein for guiding the hot gas upward to the housing; a louver plate installed on the other side of the pressure relief frame; a pair of double-opening pressure relief plates provided on the reinforcing plate, flanking the group of ventilation holes; a single-opening pressure relief plate supported on the other side of the louver plate and having one side open, wherein the structure comprises: a path for guiding and discharging the hot gas upward to the housing from between the group of ventilation holes in the reinforcing plate and the double-opening pressure relief plates; and a path for guiding and discharging the hot gas to the one side of the housing via the louver plate and the single-opening pressure relief plate. The discharge from both of the aforementioned paths is combined, resulting in a gradual flow to one of the paths.

[0015] (2) Another aspect of the present invention is characterized in that a pair of pressure relief frames are arranged in the pressure relief chamber, the reinforcing plate is installed on one of the pressure relief frames, and the louver plate is installed on the other of the pressure relief frames.

[0016] (3) Yet another aspect of the present invention is characterized in that the pair of pressure-relieving plates are provided in an opposing inclined manner on one side and the other side of the group of ventilation holes, respectively.

[0017] (4) Yet another aspect of the present invention is characterized in that the pressure relief frame is formed in a concave cross-section and comprises a bottom surface and two side surfaces, openings are formed in the two side surfaces, the hot gas flowing from the compartment into the pressure relief chamber is interrupted at one end when it hits the bottom surface, then flows around to the side surfaces and enters the pressure relief frame through the openings, and the hot gas in the pressure relief frame is discharged through both paths.

[0018] (5) In the case of a panel configuration consisting of multiple housings, the pressure relief chambers of each housing can be connected, and the hot gas in any of the housings can be distributed and discharged into the pressure relief chambers of each housing.

[0019] According to the present invention, hot gas generated in a power distribution panel due to a short circuit or the like can be safely discharged with a simple structure, ensuring the safety of surrounding workers.

[0020] A vertical cross-sectional view showing the main structure of the switchboard according to the embodiment. An exploded perspective view thereof. A perspective view of the upper part of the housing. A vertical cross-sectional view showing the heat gas discharge situation. An image diagram thereof. (a) is a perspective view of the switchboard of Patent Document 1, and (b) is a diagram of the heat gas discharge situation of (a). (a) is an upper perspective view of the switchboard of Non-Patent Document 1, and (b) is a diagram of the heat gas discharge situation of (a).

[0021] The structure (panel structure) of a switchboard according to an embodiment of the present invention will be described below. This switchboard is configured as a closed-type switchboard as described above, and by combining a simple structure, it controls the flow of hot gas generated by short-circuit accidents and other incidents to the upper front of the enclosure, thereby ensuring the safety of workers around the enclosure.

[0022] An embodiment of the distribution panel will be described with reference to Figures 1 to 5. In Figure 1, 11 indicates the grounding metal housing (metal box) of the distribution panel.

[0023] <<Configuration Example>> As shown in Figure 1, the inside of the enclosure 11 is divided into multiple compartments 12 to 14. Here, as an example, compartments 12 to 14 are designated as a circuit breaker room (VCB room) 12, a busbar room 13, and a cable room 14. The circuit breaker room 12 is located on the front side (front side: arrow F side) of the distribution panel and houses, for example, switchgear with an internal arc grade (IAC). Note that 15 in Figure 1 indicates a relay box in which controllers and the like are housed.

[0024] Behind the circuit breaker room 12 (rear side: arrow B side), there is a busbar room 13 where, for example, a three-phase busbar is installed. This busbar is connected to the main circuit terminal of the disconnecting section connected to one end of the circuit breaker.

[0025] Behind the busbar chamber 13 is a cable chamber 14 where the load-side cables are housed. These cables are connected to the main circuit terminal of the disconnecting section, which is connected to the other end of the circuit breaker.

[0026] Each of the compartments 12 to 14 is provided with an openable and closable pressure relief plate 16 at its upper end opening 12a to 14a to exhaust the hot gas from within the compartments 12 to 14. Furthermore, the upper part of the housing 11 is provided with a discharge structure to expel the hot gas exhausted from the compartments 12 to 14 to the outside of the housing 11.

[0027] To explain in detail, the top plate (not shown) of the housing 11 is formed in a frame shape, and as shown in Figure 1, a pressure relief chamber 18 is provided above the pressure relief plate 16 of the compartments 12 to 14. This pressure relief chamber 18 communicates with the inside of each of the compartments 12 to 14 when the pressure relief plate 16 opens, and hot gas from the compartments 12 to 14 flows into the pressure relief chamber 18. Note that Figure 1 shows the state when the pressure relief plate 16 is in the open position, and ventilation with the compartments 12 to 14 may be made possible by attaching a mesh to the pressure relief plate 16.

[0028] In this configuration, a pair of front and rear pressure relief frames 19 are arranged within the pressure relief chamber 18. The front pressure relief frame 19 is equipped with a grid-shaped reinforcing plate 20, the rear pressure relief frame 19 is equipped with a louver plate 21, a pair of double-opening pressure relief plates 22 provided on the reinforcing plate 20, and a single-opening pressure relief plate 23 supported on the rear side of the louver plate 21. The reinforcing plate 20, louver plate 21, and pressure relief plates 22 and 23 are installed on the opening (outside discharge section) of the top plate.

[0029] (1) Pressure relief frame 19 As shown in Figures 1 and 2, each pressure relief frame 19 is formed in a U-shape in cross-section and has a bottom plate (bottom surface) 19a, side plates (side surfaces) 19b erected on both sides of the bottom plate 19a, mounting pieces 19c bent outward from the upper end of each side plate 19b, and a horizontally elongated rectangular opening 19d formed in each side plate 19b, through which the hot gas from the pressure relief chamber 18 enters the pressure relief frame 19.

[0030] Furthermore, each mounting piece 19c of the front and rear pressure relief frames 19 has three female screw holes c1 and c2, each at equal intervals (in Figure 2, the reference numerals for the female screw holes c1 and c2 on the mounting piece 19c on one side are omitted).

[0031] (2) Reinforcement plate 20 As shown in the figure, the reinforcement plate 20 is formed in a roughly square shape and has a group of ventilation holes 25 that discharge hot gas that has entered the front pressure relief frame 19 to the upper part of the housing 1, and has a grid-like structure as described above.

[0032] This group of ventilation holes 25 is formed in a "four row and four column" configuration, with holes d1 communicating with female screw holes c1 formed on both sides of the group of ventilation holes 25, while female screw holes d2 are formed on the front and back sides of the group of ventilation holes 25 (in Figure 2, the reference numerals for the holes d1 on one side and the female screw holes d2 on the rear side are omitted).

[0033] At this time, a first through-hole (not shown) communicating with the female screw hole c1 and hole d1 is formed at the opening edge of the top plate, and the shaft portion of the bolt B1 (see Figure 3), which is inserted through hole d1 and the first through-hole, is fastened together with the female screw hole c1. In this way, the reinforcing plate 20 and the front pressure relief frame 19 are attached to the top plate.

[0034] (3) Louver plate 21 The louver plate 21 is formed in a roughly rectangular shape and is equipped with a group of vanes 26 that guide the hot gas that has entered the rear pressure relief frame 19 to the front of the housing 1 and discharge it. That is, as shown in Figure 3, a plurality of vents 26b are formed parallel to each other at equal intervals, and vanes 26a are bent downward from each vent 26b.

[0035] Holes d3 communicating with female screw holes c2 are formed on both sides of the vane group 26, while a female screw hole d4 is formed on the rear side of the vane group 26 (in Figure 2, the reference numeral for the hole d3 on one side is omitted).

[0036] Here, a second through-hole is formed in the opening edge of the top plate, communicating with the female screw hole c2 and the hole d3. The shaft of a bolt B3, which is inserted through the hole d3 and the second through-hole, is fastened to the female screw hole c2, thereby fastening the louver plate 21 and the rear pressure relief frame 19 to the top plate.

[0037] (2) Pressure relief plates 22, 23 Each pressure relief plate 22 has a flat body 22b and a bent mounting piece 22a formed at the lower end of the body 22b, as shown in Figures 2 and 3. The mounting piece 22a has a hole f1 that communicates with a female screw hole d2, and the two pressure relief plates 22 are attached to the reinforcing plate 20 in a double-opening manner by fastening the shafts of bolts B2 inserted through the front and rear holes f1 to the female screw holes d2.

[0038] At this time, the main bodies 22b of both pressure relief plates 22 face each other at an inclined angle, guiding the hot gas discharged by the ventilation holes 25 directly above the housing 11. In Figure 3, the inclination angles of each main body 22b are different, but as shown in Figure 1, each main body 22b may be at the same inclination angle, and the inclination angle can be adjusted as appropriate depending on the installation environment of the housing 11.

[0039] The pressure relief plate 23 has a flat body 23b, similar to the pressure relief plate 22, and a bent mounting piece 22a formed at the lower end of the body 23b. However, the pressure relief plate 23 is larger than the pressure relief plate 22. In addition, a hole f2 is formed in the mounting piece 23a that communicates with the female screw hole d4, and the pressure relief plate 23 is cantilevered to the rear of the louver plate 21 (the rear side of the slat group 26) by fastening the shaft of a bolt B4 inserted through the hole f2 to the female screw hole d4.

[0040] In particular, because the pressure relief plate 23 is large, its main body 23b is positioned above the vane group 26, which prevents the hot gas discharged from the vent 26b from circulating around to the rear (back side) of the housing 11.

[0041] <Discharge of Hot Gas> (1) When an internal arc accident occurs in each compartment 12 to 14, such as a short circuit, the internal pressure rises and hot gas (arc gas) is released. This causes the pressure relief plate 16 to open, and as shown by arrow P1 in Figure 1, the hot gas flows into the pressure relief chamber 18.

[0042] Here, the hot gas that flows into the pressure relief chamber 18 hits the bottom plate 19a of the pressure relief frame 19, temporarily blocking its flow and preventing it from being discharged outside the panel. After that, it flows around to the side plate 19b and enters the front and rear pressure relief frames 19 through the opening 19d.

[0043] Thus, the hot gas that has entered each pressure relief frame 19 rises toward the reinforcing plate 20 and the louver plate 21 as indicated by the arrow P3 in FIG. 5, and is discharged through a two-way path.

[0044] First, to explain the discharge path of the hot gas that has entered the front pressure relief frame 19, the hot gas rises toward the reinforcing plate 20 and is then guided upward by the ventilation hole group 25 and both pressure relief plates 22 and exhausted. That is, after flowing upward through the ventilation hole group 25 of the reinforcing plate 20, it rises while being guided by the inner surfaces of both pressure relief plates 22 and is discharged upward (substantially directly above) the housing 1 from between both pressure relief plates 22 as indicated by the arrow P4.

[0045] Next, to explain the discharge path of the hot gas that has entered the rear pressure relief frame 19, the hot gas rises toward the louver plate 21 and is then guided by the inclination of the vane group 26 and discharged from the ventilation port 26b toward the front side of the housing 11 as indicated by the arrow P5. In this case, since the main body 23b of the pressure relief plate 23 is disposed above the vane group 26 as described above, it is possible to control the hot gas from flowing around to the rear (rear side) of the housing 11. In this regard, it is possible to prevent the hot gas from staying at the corner portion (corner) of the ceiling 9 and the rear wall 10 as in the case of the hot gas G1 in FIG. 6(b).

[0046] As a result, as shown in FIG. 4, the hot gas (arrow P4) discharged substantially directly above the housing 1 and the hot gas (arrow P5) discharged to the front side of the housing 1 are combined to form a relatively gentle flow of hot gas G3 toward the front of the housing 1. That is, by controlling the discharge to the front side of the housing 11 (arrow P5) by the discharge substantially directly above the housing 11 (arrow P4), the spread of the hot gas G2 due to vortex generation as in FIG. 7(b) is suppressed.

[0047] Therefore, according to the present embodiment, the hot gas G3 does not reach a position where an operator may be present, and it is possible to protect the surrounding operators from the hot gas and ensure its safety even under severe conditions that could not be achieved with the conventional structure.

[0048] At this time, since the simple bending members 19 to 23 are used, the hot gas in the switchboard generated by a short-circuit accident or the like can be safely discharged with a simple structure, and the cost can be suppressed compared with conventional products such as Patent Document 1 and Non-Patent Document 1.

[0049] Further, by making the reinforcing plate 20 lattice-shaped, the discharge of flying objects (for example, components inside the panel) of 60 g or more at the time of explosion to the outside of the panel during a short-circuit accident is suppressed. As a result, not only the standard of the internal arc test is satisfied, but also the strength can be ensured when working at heights on the panel.

[0050] Furthermore, the housing 11 of this embodiment can secure the protection level (IP4X) of "JIS C 0920" with the pressure relief plates 22 and 23 at the uppermost part. In this sense, the opening (the part discharged to the outside of the panel) is blocked by a structure capable of controlling the discharge of hot gas, and it can be expected to eliminate the concern about the opening above the conventional switchgear.

[0051] In particular, since the protection level can be ensured, there is no restriction on the openings (vent hole groups 25 and vent port 26b groups) between the reinforcing plate 20 arranged inside the pressure relief plate 22 and the louver plate 21 arranged inside the pressure relief plate 23, and it can be manufactured at a lower cost than the structure of Non-Patent Document 1.

[0052] (2) The pressure relief chamber (the space from the pressure relief plate 16 of each sectional chamber 12 to 14 to the uppermost pressure relief plates 22 and 23) 18 functions as a room (device) that temporarily receives the expansion pressure propagated through the pressure relief plate 16. Such a room has a greater effect of relaxing the expansion pressure as its volume is larger.

[0053] Therefore, when a row of switchboards is configured by a plurality of housings 11, it is preferable to communicate and connect the pressure relief chambers 18 of adjacent housings 11 to increase the relaxation effect. In this case, as shown by the arrow P1 in FIG. 5, when hot gas is discharged from the sectional chambers 12 to 14 where a short-circuit accident has occurred to the pressure relief chamber 18, it hits the bottom plate 19a of the pressure relief frame 19 and branches in the left-right direction (L-B direction).

[0054] A portion of the hot gas that is branched here enters the opening 19d, as shown by arrow P2, and is discharged through the path indicated by arrows P3 to P5. The remaining hot gas flows into the pressure relief chamber 18 of the adjacent housing 11, as shown by arrows P6 and P7, and is discharged from there through the path indicated by arrows P3 to P5. This allows the hot gas from the housing 11 where the short-circuit fault occurred to be distributed and discharged into the pressure relief chamber 18 of the adjacent housing 11.

[0055] It should be noted that the present invention is not limited to the embodiments described above, and can be implemented with modifications within the scope of each claim. For example, the inside of the housing 11 may be divided into a plurality of compartments, and is not limited to the circuit breaker room 12, busbar room 13, and cable room 14.

[0056] 11... Enclosure 12-14... Compartment 16, 22, 23... Pressure relief plate 18... Pressure relief chamber 19... Pressure relief frame 19a... Bottom 19b... Side 19d... Opening 20... Reinforcement plate 21... Louver plate

Claims

1. A structure for a power distribution panel comprising a housing divided into multiple compartments, for discharging hot gas from within the compartments, comprising: a pressure relief plate provided at the opening of one of the compartments and opening and closing in accordance with changes in pressure within the compartment; a pressure relief chamber communicating with the opening; a pressure relief frame positioned within the pressure relief chamber; a grid-like reinforcing plate installed on one side of the pressure relief frame and having ventilation holes formed therein to guide the hot gas upward to the housing; a louver plate installed on the other side of the pressure relief frame; a pair of double-opening pressure relief plates provided on the reinforcing plate, flanking the group of ventilation holes; and a single-opening pressure relief plate supported on the other side of the louver plate, with one side open, wherein the structure includes a path for guiding and discharging the hot gas upward to the housing from between the group of ventilation holes in the reinforcing plate and the double-opening pressure relief plates; and a path for guiding and discharging the hot gas to the one side of the housing via the louver plate and the single-opening pressure relief plate. A switchboard structure characterized in that the discharge from both of the aforementioned paths is combined and flows slowly to one of the aforementioned paths.

2. The structure of the switchboard according to claim 1, characterized in that a pair of pressure relief frames are arranged in the pressure relief chamber, the reinforcing plate is installed on one of the pressure relief frames, and the louver plate is installed on the other of the pressure relief frames.

3. The structure of the switchboard according to claim 1, characterized in that the pair of pressure relief plates are provided in an opposing inclined manner on one side and the other side of the group of ventilation holes, respectively.

4. The structure of the switchboard according to claim 3, wherein the pressure relief frame is formed in a concave cross-section and comprises a bottom surface and two side surfaces, openings are formed in the two side surfaces, the hot gas flowing from the compartment into the pressure relief chamber is interrupted at one end when it hits the bottom surface, then flows around to the side surfaces and enters the pressure relief frame through the openings, and the hot gas in the pressure relief frame is discharged through both paths.

5. In the case of a panel configuration consisting of multiple enclosures, the structure of the power distribution panel according to any one of claims 1 to 5 is characterized in that the pressure relief chambers of each enclosure are connected, and the hot gas in any of the enclosures is dispersed and discharged into the pressure relief chambers of each enclosure.

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