JP2005019273A - Gas circuit breaker - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gas circuit breaker in which the discharge of heated gas can be made smoothly and the breaking performance of an arc can be improved. <P>SOLUTION: In the gas circuit breaker, a gas outflow direction changing means (22) which changes the direction of heated gas raised in temperature by being blown by an arc in a direction separating from the insulator 7 to the ground that supports a fixed side conductor 8 on the outflow direction side of the heated gas is provided on the anti-movable arc contactor 6 side of the fixed arc contactor 5. This gas outflow direction changing means (22) is constructed of a straight line section La formed on the upstream side of the heated gas and a direction changing section Lb which is formed on the downstream side and connected to the straight line section La, and the straight line section La and the direction changing section Lb are formed in a semi-circular cross section. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a gas circuit breaker, and more particularly, to a gas circuit breaker devised for treating a hot gas heated by extinguishing an arc.
[0002]
[Prior art]
Conventional gas circuit breakers are configured as described in Patent Document 1 and Patent Document 2.
[0003]
[Patent Document 1]
JP 58-16321 A (FIG. 3)
[Patent Document 2]
Japanese Patent Laid-Open No. 60-130016 (FIG. 5)
[0004]
[Problems to be solved by the invention]
Since the gas circuit breakers described in Patent Literature 1 and Patent Literature 2 are configured to change the hot gas discharge direction by 180 degrees, a part of the hot gas that has collided with the gas outflow direction changing means flows backward and the fixed arc contactor And the movable arc contact may be returned to the opening, and in such a case, the arc is not cooled and the interruption performance is deteriorated.
[0005]
The objective of this invention is providing the gas circuit breaker which can discharge | emit hot gas smoothly and can improve the interruption | blocking performance of an arc.
[0006]
[Means for Solving the Problems]
In order to achieve the above-mentioned object, the present invention supports the fixed-side conductor on the anti-movable arc contact side of the fixed arc contact with the hot gas heated by being blown by the arc on the outflow direction side of the hot gas. Gas outflow direction changing means for changing the outflow direction in a direction away from the ground insulator is provided, and the gas outflow direction changing means includes a straight section formed on the upstream side of the temperature rising gas, and the straight section formed on the downstream side. The straight section and the turning section are formed in a semicircular cross section.
[0007]
As described above, by the gas outflow direction changing means, the hot gas outflow direction is changed to a direction away from the ground insulator supporting the fixed conductor on the outflow direction side of the hot gas, thereby eliminating the backflow of the hot gas. . As a result, the hot gas can be discharged smoothly and the arc blocking performance can be improved.
[0008]
Furthermore, by forming the straight section and the direction change section of the gas outflow direction changing means into a semicircular cross section, the hot gas flowing through the gas outflow direction changing means is brought into contact with the room temperature arc extinguishing insulating gas in the ground tank. Can be cooled rapidly. Thereby, since the dielectric strength of the arc-extinguishing insulating gas that has become the hot gas can be recovered, the ground tank can be reduced in size.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a first embodiment of a gas circuit breaker according to the present invention will be described with reference to FIGS. The gas circuit breaker 1 includes a ground tank 2 whose main shape is cylindrical and filled with sulfur hexafluoride gas inside, two through conductors 3 and 4 penetrating from the ground tank 2 with an insulating material interposed therebetween, A fixed arc contact 5 and a movable arc contact 6 electrically connected to the through conductors 3 and 4 are provided.
[0010]
The fixed arc contact 5 is connected to the through conductor 3 and supported by a fixed conductor 8 supported by the ground tank 2 via a ground insulator 7, and is disposed in parallel with the longitudinal direction of the ground tank 2. ing. The cylindrical fixed-side energizing contact 9 supported by the fixed-side conductor 8 is disposed concentrically so as to cover the fixed arc contact 5.
[0011]
On the other hand, the movable arc contact 6 is supported on the side of the puffer cylinder 10 facing the fixed arc contact 5. The puffer cylinder 10 has an inner peripheral wall 11 and an outer peripheral wall 12 that are concentric with the axial center AC of the fixed arc contact 5, and the movable arc contact 6 is supported on the end of the inner peripheral wall 11 of the puffer cylinder 10. Has been. The side of the inner peripheral wall 11 and the outer peripheral wall 12 facing the fixed arc contact 5 is closed with a partition wall 13, and a gas discharge hole 14 is provided in the partition wall 13. Further, an insulating nozzle 15 covering the movable arc contact 6 is provided so as to protrude toward the fixed arc contact 5 from the outer peripheral side of the gas discharge hole 14 of the partition wall 13. The insulating nozzle 15 is configured to face the fixed arc contact 5 with a small gap therebetween.
[0012]
The puffer cylinder 10 is supported so that its outer peripheral wall 12 is slidable on the inner diameter portion of the movable energizing contact 16. The movable-side conductive contact 16 is supported by a movable-side conductor 18 connected to the through conductor 4 and supported by the ground tank 2 via a ground insulator 17. The puffer cylinder 10 is configured to move in the same direction as the axial center AC by connecting the inner peripheral wall 11 to the operation rod 19. The operation rod 19 extends outside through the ground tank 2 and is driven by an operation mechanism (not shown).
[0013]
In addition, a puffer piston 20 is inserted between the inner and outer peripheral walls 11 and 12 of the puffer cylinder 10, and the outer peripheral portion of the puffer piston 20 is fixed to the inner diameter portion of the movable conductor 18. The inner peripheral wall 11 of the puffer cylinder 10 is slidably supported on the inner diameter portion of the puffer piston 20.
[0014]
A puffer chamber 21 is formed adjacent to the partition wall 13 by the puffer cylinder 10 and the puffer piston 20.
[0015]
The configuration described above is basically the same as the configuration of the conventional gas circuit breaker. However, in the present embodiment, the cover 22 that is a gas outflow direction changing unit and a hot gas guiding unit is further connected to the fixed side. It is fixed to the conductor 8.
[0016]
The cover 22 has a straight section La fixed to the fixed conductor 8 in a direction along the axis AC, and a direction changing section Lb having a radius R continuous with the straight section La. As shown in FIG. 3, the entire section of the cover 22 has a semicircular cross section, and the semicircular opening 23 is directed in a direction not facing the ground insulator 7. This opening 23 serves as a hot gas cooling section that cools the hot gas discharged from contact with the arc-extinguishing insulating gas at room temperature.
[0017]
FIG. 4 shows a state in which the through conductors 3 and 4 are electrically connected in the above configuration. When the through conductors 3 and 4 are conducting, the movable arc contact 6 is mounted on the outer periphery of the fixed arc contact 5, and the outer peripheral wall 12 of the puffer cylinder 10 is connected to the fixed-side energizing contact 9 and the movable-side energizing contact. In this case, the volume of the puffer chamber 21 is maximized and filled with sulfur hexafluoride gas, which is an arc extinguishing insulating gas.
[0018]
When the operation rod 19 is instantaneously pulled out of the installation tank 2 (right direction in FIG. 4) by an operation mechanism (not shown) by the shut-off command, the fixed arc contact 5 and the movable arc contact 6 are separated, The stationary energizing contact 9 and the outer peripheral wall 12 of the puffer cylinder 10 are also separated. At the same time, the maximum volume puffer chamber 21 is reduced, and the arc extinguishing insulating gas filled at this time is compressed and ejected along the insulating nozzle 15 from the gas discharge hole 14 provided in the partition wall 13. The injected arc extinguishing insulating gas is blown off while the arc generated between the fixed arc contact 5 and the movable arc contact 6 is cooled, and the temperature rises to become a hot gas and proceeds to the cover 22 side. To do. FIG. 5 shows a state around the movable arc contact 6 at the time of completion of the interruption.
[0019]
As shown by arrows in FIGS. 1 and 2, a part of the hot gas traveling toward the cover 22 side is released from the opening 23 of the semicircular cover 22 into an arc extinguishing insulating gas atmosphere at room temperature. A part of the cover 22 travels along the straight section La of the cover 22 and changes its direction of travel by the direction change section Lb of radius R, and the outflow direction in the direction away from the ground insulator 7 on the outflow direction side of the hot gas. From there, it is discharged into an arc extinguishing insulating gas atmosphere at room temperature and cooled.
[0020]
Thus, by forming the straight section La and the direction changing section Lb of the cover 22 which is a gas outflow direction changing means in a semicircular cross section, the hot gas flowing through the cover 22 is turned off at room temperature in the ground tank 2. It can be contacted with arcuate insulating gas and can be cooled rapidly. Thereby, since the dielectric strength of the arc-extinguishing insulating gas that has become the hot gas can be recovered, the ground tank can be reduced in size.
[0021]
Further, by changing the outflow direction of the hot gas to the direction away from the ground insulator 7 on the outflow direction side of the hot gas by the cover 22, the hot gas flows backward as in the conventional case to prevent rapid interruption of the arc. Nothing will happen. As a result, it is possible to smoothly discharge the hot gas and quickly bring it into contact with the arc extinguishing insulating gas at room temperature for cooling, thereby improving the arc breaking performance.
[0022]
The arc-extinguishing insulating gas that has turned into a hot gas by extinguishing the arc has a lower density than the arc-extinguishing insulating gas at room temperature, and further has a lower dielectric strength because it is partially ionized. Yes. Therefore, quenching the arc and quenching the hot gas is an essential condition for downsizing the ground tank.
[0023]
FIG. 6 shows the relationship between the moving distance L of the hot gas from the tip of the fixed arc contact 5 and the hot gas temperature T, and quantitatively includes the temperature region of the hot gas, the blowing pressure, and further the insulating nozzle 15. Although somewhat different depending on the shape of the arc extinguishing chamber, it can be assumed that T is proportional to (1 / L) to (1 / (L × L)).
[0024]
FIG. 7 shows the relationship between the hot gas temperature T and the allowable electric field E at the hot gas outlet, and quantitatively varies slightly depending on the temperature region of the hot gas, but in the case of sulfur hexafluoride gas, Up to 3000K, T can be assumed to be proportional to (−logE + α) as shown. Α is a constant.
[0025]
From the relationship shown in FIG. 6, in order to lower the hot gas temperature T, the hot gas moving distance L may be increased. However, if the hot gas moving distance L is increased, the length of the ground tank 2 is consequently increased. Therefore, the gas circuit breaker cannot be downsized. Thus, if the desired minimum value of the hot gas temperature T is known, the required travel distance L of the hot gas can be found. Therefore, the minimum value of the hot gas temperature T can be determined by the relationship with the allowable electric field E in FIG. That is, when the static electric field at the outlet of the hot gas is E1, it is necessary to set the temperature of the hot gas passing therethrough to be equal to or lower than T1, so that the hot gas moving distance at the hot gas temperature T1 in FIG. It turns out that it is. Therefore, by forming the direction change section Lb of the cover 22 at a position about L1 away from the tip of the fixed arc contact 5, it is possible to release the hot gas into the arc extinguishing insulating gas at room temperature.
[0026]
By the way, the cover 22 is made of a metal material in consideration of heat resistance and mechanical strength. And considering the price, it is desirable to make the cover 22 made of casting.
[0027]
Further, by forming a coating film made of a heat-resistant insulating material on the surface of the cover 22 made of a metal material, the hot gas does not directly touch the cover 22 made of the metal material. One cause of the flash of the cover 22 is the emission of electrons from the cover 22, and the flash is suppressed by suppressing the emission of electrons with a heat-resistant insulating coating. In addition, by applying a heat-resistant coating to the portion exposed to the hot gas inside the cover 22 to which the heat-resistant insulating coating is applied, peeling of the heat-resistant insulating coating can be prevented and electron emission can be effectively suppressed. it can. In addition, although a general thing may be sufficient as a coating material for coating films, application | coating of tetrafluoroethylene resin etc. is also technically possible.
[0028]
As described above, applying a coating film made of a heat-resistant insulating material to the cover 22 can prevent flashing from the cover 22 due to hot gas, and thus contributes to the downsizing of the gas circuit breaker.
[0029]
It should be noted that it is desirable to cope with the increase in the rated breaking current in the gas circuit breaker having a certain rated voltage only by changing the cover 22. That is, since the hot gas generated at the time of current interruption increases due to the increase of the rated interruption current, it is necessary to enlarge the cover 22, but when the cover 22 is formed of a metal material, the distance from the ground tank 2 becomes larger if the cover 22 is made larger. As a result, the electric field at the tip of the cover 22 is increased. Therefore, by forming the cover 22 from a heat-resistant insulating material, the electric field at the front end of the cover that changes the outflow direction of the hot gas can be kept low. As a result, it is not necessary to ensure a large insulation distance between the ground tank 2 and a large rated breaking current can be handled without increasing the size of the ground tank 2.
[0030]
Next, 2nd Embodiment of the gas circuit breaker by this invention is described based on FIG.8 and FIG.9. The structure shown here is a gas flow agitating means for lowering the temperature of the hot gas, and the agitating member 24 that is also a cooling means is fixed to the fixed arc contact 5 facing the vicinity of the non-movable arc contact 6 side end. It is provided on the conductor 8.
[0031]
According to the above configuration, the flowing hot gas collides with the stirring member 24 and is stirred or dispersed in the process of flowing out, so that the temperature of the hot gas reaching the cover 22 can be lowered.
[0032]
The stirring member 24 has a circular cross section, but the cross sectional shape is not particularly limited as long as it has a function of stirring and dispersing hot gas. Further, the stirring member 24 may be provided integrally with the fixed side conductor 8 or may be attached to the fixed side conductor 8 so as to be detachable.
[0033]
FIG. 10 shows a third embodiment of the gas circuit breaker according to the present invention, in which an obstacle wall 25 is provided in a straight section La inside the cover 22. By providing the obstacle wall 25, a part of the hot gas changes its direction before reaching the direction changing section Lb of the cover 22, and enters the arc-extinguishing insulating gas atmosphere at room temperature from the opening of the cover 22 having a semicircular cross section. Released and cooled. Further, the hot gas whose direction has been changed by the obstacle wall 25 has a function of changing the discharge direction of the hot gas to be moved straight to the opening side of the cover 22 or stirring and cooling the gas. Or it becomes a cooling means.
[0034]
FIG. 11 shows a fourth embodiment of the gas circuit breaker according to the present invention, in which an obstacle wall 26 is provided in the direction change section Lb inside the cover 22. By providing this obstacle wall 26, the same operational effects as those of the third embodiment can be obtained. Furthermore, according to the present embodiment, since the amount of hot gas reaching the end portion of the cover 22 can be limited, the dielectric strength of the end portion of the cover 22 can be maintained.
[0035]
The fifth embodiment of the gas circuit breaker according to the present invention shown in FIG. 12 is that the cover 22 is fixed to the fixed conductor 8 so as to be detachable.
[0036]
As described above, the cover 22 can be attached and detached so that the fixed arc contact 5, the movable arc contact 6, and the insulating nozzle 15 that are consumables can be easily replaced. That is, after the cover 22 is removed, the replacement work can be performed by releasing the fixed arc contact 5, the movable arc contact 6, and the insulating nozzle 15, which are consumables, and moving them sequentially in the direction of the arrow. is there. In addition, by preparing a plurality of types of covers 22 corresponding to the amount of generated hot gas, it is possible to cope with each rating, so that the productivity of the gas circuit breaker can be improved.
[0037]
【The invention's effect】
As described above, according to the present invention, it is possible to obtain a gas circuit breaker capable of smoothly discharging hot gas and improving the arc breaking performance.
[Brief description of the drawings]
FIG. 1 is a longitudinal side view showing a first embodiment of a gas circuit breaker according to the present invention.
2 is a partially enlarged view of FIG.
3 is an enlarged cross-sectional view taken along line AA in FIG.
4 is an enlarged view of a main part showing when the gas circuit breaker of FIG. 1 is cut off. FIG.
5 is an enlarged view of a main part showing when the gas circuit breaker of FIG. 1 is energized.
FIG. 6 is a diagram showing a relationship between a hot gas temperature and a hot gas moving distance.
FIG. 7 is a diagram showing a relationship between an allowable electric field and a hot gas temperature.
FIG. 8 is a longitudinal side view showing a second embodiment of the gas circuit breaker according to the present invention.
9 is a sectional view taken along line BB in FIG.
FIG. 10 is a longitudinal side view showing a third embodiment of a gas circuit breaker according to the present invention.
FIG. 11 is a longitudinal side view showing a fourth embodiment of a gas circuit breaker according to the present invention.
FIG. 12 is a longitudinal side view showing a fifth embodiment of a gas circuit breaker according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Gas circuit breaker, 2 ... Ground tank, 5 ... Fixed arc contact, 6 ... Movable arc contact, 7 ... Ground insulator, 8 ... Fixed side conductor, 10 ... Puffer cylinder, 15 ... Insulation nozzle, 19 ... Operation Rod, 20 ... Puffer piston, 21 ... Puffer chamber, 22 ... Cover, 24 ... Stirring member, 25, 26 ... Obstruction wall.

Claims (7)

A grounding tank filled with an arc-extinguishing insulating gas, a fixed arc contact housed in the grounding tank, a fixed side conductor connected to the fixed arc contact, and the fixed side conductor to the ground tank Insulating and supporting ground insulator, a movable arc contact disposed so as to be able to contact and separate from the fixed arc contact, and a buffer that compresses the arc-extinguishing insulating gas in cooperation with the movable arc contact A gas circuit breaker configured to blow an arc-extinguishing insulating gas in the puffer chamber to a separation portion of the fixed arc contactor and the movable arc contactor when the current is interrupted,
The hot gas heated by blowing an arc-extinguishing insulating gas to the separation part of the fixed arc contact and the movable arc contact on the anti-movable arc contact side of the fixed arc contact is discharged from the hot gas. Gas outflow direction changing means for changing the outflow direction in a direction away from the ground insulator on the direction side is provided, and the gas outflow direction changing means has a semicircular cross section and a straight section upstream of the temperature rising gas And the gas circuit breaker characterized by having a direction change area connected with the said linear area downstream. The gas circuit breaker according to claim 1, wherein a length of the direction change section in the same direction as the straight section is longer than the straight section. A gas flow agitating means for agitating the gas flow of the hot gas is provided between an end of the stationary arc contact on the side opposite to the movable arc contact and the end of the gas outflow direction changing means. Item 1. The gas circuit breaker according to Item 1. 2. The gas according to claim 1, wherein cooling means for cooling the hot gas is provided between an end of the stationary arc contact on the side of the counter-movable arc contact and a terminal of the gas outflow direction changing means. Circuit breaker. 2. The gas circuit breaker according to claim 1, wherein the gas outflow direction changing means is detachably supported on the side of the stationary arc contact opposite to the movable arc contact. The gas circuit breaker according to claim 1, wherein the gas outflow direction changing means is made of a heat-resistant insulating material. A fixed arc contact housed in a ground tank filled with arc-extinguishing insulating gas, a fixed side conductor connected to the fixed arc contact, and the fixed side conductor is insulated and supported from the ground tank. A grounding insulator, a movable arc contact disposed so as to be able to contact and separate from the fixed arc contact, and a puffer chamber for compressing the arc-extinguishing insulating gas in cooperation with the movable arc contact; In the gas circuit breaker configured to blow the arc extinguishing insulating gas in the puffer chamber to the opening portion of the fixed arc contactor and the movable arc contactor at the time of current interruption,
An arc extinguishing insulation of a hot gas heated at a room temperature by blowing an arc extinguishing insulating gas to the opening part of the fixed arc contactor and the moving arc contact on the anti-moving arc contact side of the fixed arc contactor There is provided a hot gas guide means comprising a hot gas cooling section that comes into contact with a gas and a gas outflow direction changing section that changes the outflow direction in a direction away from the ground insulator on the outflow direction side of the hot gas. A gas circuit breaker.

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