JP5209000B2 - Switchgear - Google Patents

Description

  The present invention relates to a switch gear, and more particularly to a switch gear having a function of preventing moisture absorption of a main circuit insulator.

  A metal closed switchgear (hereinafter referred to as a switchgear) used as a substation facility in a power plant or the like has devices such as a circuit breaker housed inside a casing, and the ambient temperature of these devices is the allowable temperature of the device. Therefore, the inside of the housing is ventilated by natural ventilation (ventilation by natural convection) and forced ventilation (forced ventilation by a ventilation fan) (for example, Patent Document 1).

JP 2000-261916 A

  However, since the outside air is taken into the housing during ventilation, if the relative humidity of the outside air is high, the relative humidity inside the housing rises, the main circuit insulation deteriorates due to moisture absorption, and the insulation resistance This causes a problem of lowering.

  For this reason, a heater is installed inside the housing, the heater is operated or stopped based on the humidity data detected by the humidity detector, and the relative humidity inside the housing is not affected by the main circuit insulator. It is adjusted in.

  However, in switch gears compliant with JEM standard PW class and MW class, the inside of the housing is divided into a plurality of sections (a section for storing the main busbar, a section for storing the circuit breaker, a section for storing the power cable, etc.) ), It is difficult to adjust the overall relative humidity inside the housing within a range where the main circuit insulator is not affected.

  That is, in the above type of switchgear, air convection inside the housing is inhibited by the partition plate, so that a portion where air stagnates is formed inside the housing. In addition, the air heated by heat generated by the heater, the main bus, etc. rises mainly along the partition plate in each compartment by the draft force, but hardly air flows between the adjacent compartments. For this reason, only the natural ventilation and forced ventilation described above cannot sufficiently raise the temperature of the portion where the relative humidity inside the housing is to be lowered, and the main circuit insulator is unavoidably affected by moisture absorption.

  The results of thermal fluid analysis using temperature measurement data of actual switchgear are shown in FIG. 3 and FIG. FIG. 3 shows an analysis model, and FIG. 4 shows a partial air flow of the analysis result. In this analysis model, the inside of the housing 2 accommodates a section for storing the main bus 40 by the partition plates 21 to 25, a section for storing the circuit breaker 42, a section for storing the instrument transformer 43, and the power cable 41. It is divided into compartments, intake ports 5a and 6a are provided at the bottom of the housing 2, exhaust ports 11 are provided at the top, heaters 30 and 31 are provided at the bottom inside the housing 2, and natural ventilation and forced ventilation are provided. This is a switch gear 51 of the type that ventilates the inside of the housing 2.

  From this analysis result, in this type of switchgear 51, there is almost no air flow between adjacent compartments inside the housing 2, and the air heated by the heaters 30 and 31 is distributed throughout the inside of the housing 2. It can be seen that the relative humidity inside the housing 2 cannot be adjusted within a range in which the main circuit insulator is not affected. It can also be seen that although there is a local dehumidifying effect in the vicinity of the heaters 30 and 31, the entire interior of the housing 2 has almost no dehumidifying effect due to the influence of outside air taken into the housing 2.

  The present invention has been made in view of the above-described conventional problems, and provides a switchgear that can adjust the overall relative humidity inside the housing within a range in which the main circuit insulator is not affected. The purpose is to provide.

In order to solve the above problems, the present invention employs the following means.
That is, the present invention has a housing that is partitioned into a plurality of compartments by a partition plate, the interior of the housing is ventilated by natural ventilation and forced ventilation, and the housing is placed at the bottom of the housing. A switchgear provided with a heater for heating the air inside the body, provided at the lower end of the front part and the rear part of the case with an intake port for taking outside air into the case, In the upper part, there is provided an exhaust port through which the outside air taken into the housing and circulated through the housing flows out to the outside of the housing, and a ventilation fan is provided in the exhaust port, and the partition At least a part of the plate is made of a material having air permeability, and air can flow between adjacent compartments through the ventilation portion of the partition plate, and in the vicinity of the intake port inside the housing. Circulates air inside the housing , and A circulation fan is provided for limiting the amount of outside air taken into the housing from the air inlet .

According to the switchgear of the present invention, the air heated by the heat generated by the heater, the main bus, etc. inside the housing rises along the partition plate by the drafting force, and by the operation of the circulation fan, The adjacent compartments circulate with each other through the ventilation portion of the partition plate, and circulate throughout the interior of the housing.
Accordingly, since the heated air can be circulated throughout the inside of the housing, the overall temperature inside the housing can be adjusted almost uniformly, and the relative humidity inside the housing can be mainly controlled. The circuit insulator can be adjusted within a range not affected.
In addition, air inlets that take in outside air into the inside of the housing are provided at the lower ends of the front and rear of the housing, and outside air that is taken into the inside of the housing and circulated inside the housing is provided at the top of the housing. Provide an exhaust port to flow outside the housing, provide a ventilation fan at the exhaust port, circulate the air inside the housing near the intake port inside the housing, By providing a circulation fan that restricts the amount of outside air taken into the air, the air flow from the circulation fan blocks the outside air flowing into the housing through the intake port by the operation of the ventilation fan, This prevents the outside air from being taken in more than necessary. Thereby, when the relative humidity of the outside air is high, the relative humidity inside the housing is not increased by the outside air.

  In the present invention, circulation fans may be provided above and below the inside of the casing.

According to the switchgear of the present invention, the circulation fan provided in the upper part inside the casing can circulate the air in the upper part inside the casing, and the circulation fan provided in the lower part inside the casing. The air in the lower part inside the housing can be circulated. Therefore, the heated air can be efficiently circulated throughout the interior of the housing.
In addition, the circulation fan provided at the lower part of the inside of the housing makes it difficult for outside air to enter the inside of the housing, so it is possible to prevent outside air from being taken into the inside of the housing more than necessary. When the humidity is high, the relative humidity inside the housing can be prevented from being increased by outside air.

  Furthermore, in the present invention, a humidity detector for detecting the humidity inside the housing is provided at the bottom inside the housing, and the operation of the circulation fan is controlled based on the detection data of the humidity detector. It may be configured as described above.

  According to the switchgear of the present invention, the relative humidity inside the housing is maintained within a predetermined range by controlling the operation of the circulation fan based on the relative humidity inside the housing detected by the humidity detector. Will be.

  Furthermore, in the present invention, a temperature detector for detecting the temperature inside the casing is provided at the bottom of the casing, and the operation of the circulation fan is controlled based on the detection data of the temperature detector. It may be configured as described above.

  According to the switchgear of the present invention, the relative humidity inside the housing is maintained within a predetermined range by controlling the operation of the circulation fan based on the temperature inside the housing detected by the temperature detector. It will be.

  Furthermore, in this invention, it is good also as providing the circulation fan in the division in which the apparatus inside the said housing | casing is accommodated.

  According to the switchgear of the present invention, air can be circulated efficiently in the compartment in which the device is accommodated, so that it is possible to prevent the metal part and the insulating part of the device from being affected by moisture.

As described above, according to the switchgear of the present invention, the air heated by the heat generated by the heater, the main bus, and the like rises inside the compartment along the partition plate, and the circulation fan. As a result of the operation, the adjacent compartments mutually circulate through the partition plate. Therefore, since the heated air can be circulated throughout the inside of the housing, the overall relative humidity inside the housing can be kept within a predetermined range, and the main circuit insulator absorbs moisture and deteriorates. And it can prevent that insulation resistance falls.
In addition, the flow of air from the circulation fan blocks the outside air flowing into the housing through the air intake by the operation of the ventilation fan, and prevents the outside air from being taken into the housing more than necessary. When the relative humidity of the outside air is high, the relative humidity inside the housing is not increased by the outside air, and the entire relative humidity inside the housing can be kept within a predetermined range.

It is the schematic which showed one Embodiment of the switchgear by this invention. It is explanatory drawing which shows the result (flow velocity distribution) which carried out the thermal fluid analysis using the temperature measurement data of the switchgear of FIG. It is the schematic which showed an example of the conventional switchgear. It is explanatory drawing which shows the result (flow velocity distribution) which carried out the thermal fluid analysis using the temperature measurement data of the conventional switchgear.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows an embodiment of a switchgear according to the present invention. A switchgear 1 according to the present embodiment is a metal closed type switchgear (hereinafter referred to as a switchgear 1) used as a substation equipment such as a power plant, and has a housing 2 that is divided into a plurality of compartments. The main bus 40, the power cable 41, and various devices (the circuit breaker 42, the instrument transformer 43, etc.) are housed inside the housing 2.

  The housing 2 has a box shape composed of a bottom plate 3, a top plate 4, a front door 5, a rear door 6, and two side plates 7, and a rectangular parallelepiped space 8 is provided therein. The space 8 is divided into a plurality of sections. The lower ends of the front door 5 and the rear door 6 of the housing 2 are provided with intake ports 5a and 6a communicating with the inside and outside of the space 8, and the outside air is a space inside the housing 2 through the intake ports 5a and 6a. 8 is taken in. Note that the front door 5 and the rear door 6 of the housing 2 are configured to be openable and closable.

  Above the top plate 4 of the housing 2, a roof plate 9 having a predetermined gradient is provided at an interval, and a ventilation duct 10 is provided between the roof plate 9 and the top plate 4. The ventilation duct 10 communicates with the space 8 inside the housing 2 through a plurality of ventilation holes 4 a provided in the top plate 4. At both ends (left and right ends in the figure) of the ventilation duct 10 are respectively provided exhaust ports 11 that communicate the inside and outside of the ventilation duct 10, and a ventilation fan 12 is provided inside the exhaust port 11 on one end side (left end side in the figure). It has been. By the operation of the ventilation fan 12, outside air is taken into the space 8 inside the housing 2 from the intake ports 5 a and 6 a, and the outside air circulates in the space 8 inside the housing 2 to vent holes 4 a of the top plate 4. Flows into the ventilation duct 10 and flows out from the ventilation duct 10 through the discharge port 11 to the outside of the housing 2.

  In the present embodiment, the space 8 inside the housing 2 is divided into a first compartment 15 in which the power cable 41 is accommodated and a second compartment 18 in which the main bus 40 is accommodated by the plurality of partition plates 21 to 25. Are divided into four sections, a third section 19 in which the instrument transformer 43 is housed, and a fourth section 20 in which the circuit breaker 42 is housed. It is divided into two sections, a first section 16 and a first-second section 17. Note that the lower ends of the first section 15 and the second section 18 communicate with each other.

  The partition plates 21 to 25 have a plate shape formed from a material having air permeability. In the present embodiment, the partition plate is made of an expanded metal having an opening ratio of 76% and a ventilation resistance coefficient of 0.4. The expanded metal is provided with ventilation portions 22a to 25a having a plurality of ventilation holes in a part of the partition plates 21 to 25. The partition plate 21 is not provided with a ventilation portion.

  With the partition plates 22 to 25 having the vent portions 22 a to 25 a configured as described above, air is circulated between the upper ends of the first compartment 15 and the second compartment 18 via the vent portion 23 a of the partition plate 23. Then, air is circulated between the second section 18 and the third section 19 via the ventilation portion 24a of the partition plate 24, and the ventilation of the partition plate 25 is performed between the second section 18 and the fourth section 20. The air can be mutually circulated through the section 25a, and the air can be circulated between the 1-1 section 16 and the 1-2 section 17 through the ventilation section 22a of the partition plate 22. it can.

  In addition, the ventilation parts 22a-25a of the partition plates 22-25 may be comprised not only with an extended metal but what has the same function. Moreover, in this Embodiment, although a part of partition plates 22-25 are comprised by the expanded metal, you may comprise the whole partition plates 22-25 by an expanded metal.

  Heaters 30 and 31 are provided on the bottom of the first and second sections 17 and 17 at the lower stage of the first section 15 and the bottom of the second section 18, respectively. The air at the bottom and the air at the bottom of the second compartment 18 are heated. Further, the air in the first section 15 is also heated by the heat generated by the power cable 41. Furthermore, the air in the second compartment 18 is also heated by the heating of the main bus 40.

  The heated air in the first-second section 17 rises along the left and right partition plates 21 and 23 of the first-second section 17 by the draft force, and the first-second section 17 and the first-first section 16 It flows into the 1-1 section 16 through the ventilation part 22a of the partition plate 22 between the two. The heated air that has flowed into the first section 16 flows into the second section 18 through the ventilation portion 23 a of the partition plate 23 between the first section 16 and the second section 18. Alternatively, the air flows into the ventilation duct 10 from the first section 16 through the vent hole 4 a of the top plate 4.

  The heated air in the second section 18 rises along the left and right partition plates 23, 24, 25 of the second section 18 by the draft force, and the partition plate 24 between the second section 18 and the third section 19. The air flows into the third section 19 and the fourth section 20 through the vent section 24 a and the vent section 25 a of the partition plate 25 between the second section 18 and the fourth section 20. Alternatively, the air flows into the ventilation duct 10 from the second section 18 through the vent hole 4 a of the top plate 4.

  Circulation fans 35 and 36 are provided at the upper ends of the right partition plate 24 of the third section 19 and the right partition plate 25 of the fourth section 20, respectively. By the operation of these circulation fans 35 and 36, In the upper part of the third compartment 19 and the upper part of the fourth compartment 20, air flows in the direction of the arrows in the figure, and these air flows collide with the inner surface of the rear door 6 of the housing 2 and then move up and down. They are distributed in the horizontal direction and circulate in the third compartment 19 and the fourth compartment 20 and in the space 8 inside the housing 2. Alternatively, the air flows into the ventilation duct 10 through the vent hole 4 a of the top plate 4 and flows out from the ventilation duct 10 through the exhaust port 11.

  Due to the flow of air by the circulation fan 36 in the fourth section 20, the outside air flowing into the housing 2 through the intake port 6 a is blocked by the operation of the ventilation fan 12, and the outside air is taken into the housing 2 more than necessary. Is prevented. Thereby, when the relative humidity of the outside air is high, the relative humidity inside the housing 2 is not increased by the outside air.

  A humidity detector 32 that detects the relative humidity near the bottom inside the housing 2 and a temperature detector 33 that detects the temperature near the bottom are provided at the bottom inside the housing 2, and the humidity detector 32 detects the humidity. Based on the humidity data and the temperature data detected by the temperature detector 33, the operation of the circulation fans 35 and 36 is controlled.

  In the present embodiment, the circulation fans 35 and 36 are operated when the relative humidity inside the housing 2 is 60% or more, and when the relative humidity is less than 60%, the circulation fans 35 and 36 are operated. The operation of the circulation fans 35 and 36 is controlled so as to stop the operation. This is because when the relative humidity inside the housing 2 exceeds 60%, the corrosion of the metal is rapidly accelerated, and when the relative humidity is higher than 70%, the insulation resistance of the insulator rapidly decreases.

  Further, in the present embodiment, the circulation fan 35 and 36 are operated so that the circulation fans 35 and 36 are operated when the temperature inside the enclosure 2 becomes about 10 ° C. or less regardless of the relative humidity inside the enclosure 2. The operation of 35 and 36 is controlled. This is because when the internal temperature of the housing 2 is about 10 ° C. or less, the relative humidity changes remarkably with a slight temperature change. If the operation of the circulation fans 35, 36 is controlled in this region, the circulation fan 35, This is because the operation and stop of 36 are frequently repeated, and a sufficient dehumidifying effect cannot be obtained.

  In the switchgear 1 of the present embodiment configured as described above, the outside air is taken into the housing 2 from the intake ports 5a and 6a by the operation of the ventilation fan 12, and flows through the housing 2 to circulate the top plate 4. The inside of the housing 2 is ventilated by flowing into the ventilation duct 10 through the ventilation hole 4a and out of the housing 2 through the exhaust port 11 from the ventilation duct 10.

  In addition, by the operation of the heaters 30 and 31, the air in the bottom of the housing 2 (the bottom of the first and second sections 17 and the bottom of the second section 18) is heated, and the heated air is heated by the draft force. It rises along the partition plates 21 and 23 in the first section 15 and the partition plates 23, 24 and 25 in the second section 18.

  At this time, by operating the circulation fans 35 and 36, the heated air flows from the first section 16 into the second section 18 through the ventilation portion 23 a of the partition plate 23, and the second section 18. The air flows into the third compartment 19 from the compartment 18 through the ventilation portion 24 a of the partition plate 24. Further, the heated air flows from the second section 18 into the fourth section 20 through the ventilation portion 25 a of the partition plate 25. The heated air that has flowed into the third section 19 and the fourth section 20 collides with the inner surface of the rear door 6 of the housing 2 and is distributed in the vertical direction and the horizontal direction along the inner surface of the rear door 6. It circulates in the third compartment 19 and the fourth compartment 20 and in the space 8 inside the housing 2.

  Therefore, there is no portion where air stagnates inside the housing 2, and the heated air can be circulated throughout the interior of the housing 2, thereby increasing the overall temperature inside the housing 2. The relative humidity inside the housing 2 can be adjusted within a range in which the main circuit insulator is not affected.

  In addition, the circulation fans 35 and 36 are provided in the partition plate 24 of the third compartment 19 in which the instrument transformer 43 is accommodated and the partition plate 25 in the fourth compartment 20 in which the circuit breaker 42 is accommodated, respectively. Air in the third compartment 19 and the fourth compartment 20 can be circulated efficiently, and the metal transformer and the circuit breaker 42 can be effectively prevented from being affected by moisture. .

  Furthermore, since the circulation fan 36 provided in the partition plate 25 of the fourth section 20 can make it difficult for outside air to flow into the housing 2 through the intake port 6a, the outside air can enter the housing 2 more than necessary. When the relative humidity of the outside air is high, the relative humidity inside the housing 2 is not increased by the outside air.

  Further, the operation of the circulation fans 35 and 36 is controlled so that it operates when the relative humidity inside the housing 2 becomes 60% or more and stops when the relative humidity becomes less than 60%. Therefore, when the relative humidity inside the housing 2 exceeds 60%, it is possible to prevent the insulation resistance of the main circuit insulator from rapidly decreasing.

  Furthermore, regardless of the relative humidity inside the housing 2, the operation of the circulation fans 35 and 36 is controlled so that the circulation fans 35 and 36 are operated when the temperature inside the housing 2 becomes about 10 ° C. or less. Therefore, at about 10 ° C. or less where the relative humidity changes significantly, the operation and stop of the circulation fans 35 and 36 are not frequently repeated, and a desired dehumidifying effect is obtained.

  FIG. 2 shows a part of air flow by thermal fluid analysis using temperature measurement data of the switchgear 1 of the present embodiment. From this analysis result, in the switchgear 1 according to the present embodiment, air can be efficiently circulated between adjacent compartments inside the housing 2, and the air heated by the heaters 30 and 31 is contained inside the housing 2. It can be seen that the entire relative humidity inside the housing 2 can be adjusted within a range in which the main circuit insulator is not affected.

DESCRIPTION OF SYMBOLS 1,51 Switchgear 2 Housing | casing 3 Bottom plate 4 Top plate 4a Vent hole 5 Front door 5a Intake port 6 Rear door 6a Intake port 7 Side plate 8 Space 9 Roof plate 10 Ventilation duct 11 Exhaust port 12 Ventilation fan 15 First section 16 First 1-1 section 17 1-2 section 18 2nd section 19 3rd section 20 4th section 21 Partition plate 22 Partition plate 22a Ventilation portion 23 Partition plate 23a Ventilation portion 24 Partition plate 24a Ventilation portion 25 Partition plate 25a Ventilation portion 30 Heater 31 Heater 32 Humidity detector 33 Temperature detector 35 Circulation fan 36 Circulation fan 40 Main bus 41 Power cable 42 Circuit breaker 43 Instrument transformer

Claims (5)

The housing has a housing that is partitioned into a plurality of compartments by a partition plate, the interior of the housing is ventilated by natural ventilation and forced ventilation, and the air inside the housing is placed at the bottom of the housing. A switchgear provided with a heater for heating,
An intake port for taking in outside air into the inside of the housing is provided at the front and rear lower ends of the housing, and the air is taken into the housing at the upper part of the housing and flows through the inside of the housing. An exhaust port for allowing the outside air to flow out to the outside of the housing is provided, and a ventilation fan is provided at the exhaust port,
At least a part of the partition plate is formed of a material having air permeability, and air can be circulated between adjacent compartments through the ventilation portion of the partition plate, and the intake port inside the housing A switchgear characterized in that a circulation fan is provided in the vicinity for circulating air inside the casing and for limiting the amount of outside air taken into the casing from the intake port .   The switchgear according to claim 1, wherein circulation fans are provided above and below the inside of the casing.   A humidity detector that detects humidity inside the housing is provided at the bottom of the housing, and the operation of the circulation fan is controlled based on detection data of the humidity detector. The switchgear according to claim 1 or 2, characterized in that   A temperature detector for detecting the temperature inside the housing is provided at the bottom inside the housing, and the operation of the circulation fan is controlled based on detection data of the temperature detector. The switchgear according to claim 1 or 2, characterized in that   The switchgear according to any one of claims 1 to 4, wherein a circulation fan is provided in a section in which equipment inside the casing is stored.

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