JP2586568B2 - Gas liquefaction prevention device for gas circuit breaker - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a gas circuit breaker. More particularly, it relates to preventing gas inside a circuit breaker from liquefying in a low temperature environment.

[Prior Art] FIG. 3 is a cross-sectional view showing a part of a conventional gas circuit breaker, in particular, the vicinity of an operation rod protruding from a shutoff portion. In the figure, (1) is a blocking part, (2) is a supporting insulator for supporting the blocking part (1), and (3) is a gas filled in the blocking part (1) and the supporting insulator (2). This is a gas seal mechanism for preventing leakage from the gap at the operation rod (4), which is a movable part. (5) is a housing of the gas circuit breaker.

Next, the operation will be described. The inside of the circuit breaker is filled with high-pressure gas. When such a gas circuit breaker was installed in a cold region and the environmental temperature dropped to, for example, −40 ° C., liquefaction of the high-pressure gas filled in the cutoff section (1) and the support insulator (2) occurred. Since the gas inside the circuit breaker is not supplied from the outside, the liquefaction of the gas deteriorates the breaking performance of the gas circuit breaker. To prevent this, the gas inside the circuit breaker must be heated forcibly. By the way, conventionally, there was no good gas heating device.

[Problems to be Solved by the Invention] Therefore, the conventional gas circuit breaker is configured as shown in FIG. 3, and in order to cope with gas liquefaction in cold regions, gas liquefaction is performed in anticipation of performance degradation. There have been problems such as the necessity of using a gas circuit breaker having a large shutoff ability.

The present invention has been made in order to solve the above-mentioned problems, and a circuit breaker that satisfactorily heats a liquefied gas so as not to use a large gas circuit breaker having a margin in anticipation of performance degradation. It is an object to obtain a device for preventing gas liquefaction in the inside.

Means for Solving the Problems A gas liquefaction prevention device for a gas circuit breaker according to the present invention uses a thermosiphon to circulate a heat medium and return a thermosiphon to return a liquefied gas to an original gas. The liquid and the gas are circulated by utilizing the heat medium and heat exchange is performed with the heat medium as a heat source.

[Operation] In the gas liquefaction prevention apparatus according to the present invention, the liquid / gas guided from below into the liquid / gas heating pipe for heat exchange with the heat medium is reduced in density by being heated, and gains buoyancy to obtain its own power. Enter the cut-off part and the support insulator with. In addition, the liquefied gas condensed on the inner wall of the blocking part and the support insulator flows down the inner wall and reaches the liquid / gas heating pipe by itself. On the other hand, the heat medium also circulates by natural fall for cooling by heat exchange with the liquid / gas and natural rise for heating by a heat source. Thus, a pump for forcibly circulating the gas is not required, and the liquefied gas is efficiently returned to the original gas.

Embodiment An embodiment of the present invention will be described below with reference to FIG. In the figure, (1) is a breaking part, (2) is a supporting insulator,
(3) is a gas seal, (4) is an operation rod, and (5) is a circuit breaker housing, which is the same as the conventional one.
(6) is a chamber for storing liquefied gas. Liquefied gas (13) accumulates in this chamber. Know the amount with the first level gauge (19).
(15) is an evaporator. This evaporator (15) is connected to the chamber (6) via a gas gate valve (10). The gas gate valve (10) is normally open. The evaporator (15) has a plurality of liquid / gas heating tubes (8) extending vertically. This liquid
An upper end and a lower end of the liquid / gas heating pipe (8) communicate with each other through the inside of the gas (8). The liquid level of the liquefied gas (13) of these liquid / gas heating pipes (8) is measured by a second liquid level gauge (20).
To know. (21) is a gas intake / exhaust valve. (16) is a heater. The heater (16) has a heating medium (14) and a heating source (17) such as an electric heater for heating the heating medium (14). The heat medium (14) passes through the passage (7) inside the evaporator (15) and outside the liquid / gas heating pipe (8) in a zigzag manner but in a vertical direction as a whole. In addition, (22) is a gas chamber for absorbing a volume change of the heat medium when the heat medium (14) is heated and cooled. Also, (1
1) is a heat insulating material surrounding the heater (16) and the evaporator (15).

Next, the operation will be described. The liquefied gas condensed on the inner wall of the cut-off portion (1) and the support insulator (2) flows down and accumulates in the liquefied gas storage chamber (6). As shown in FIG. 1, the liquid level of the liquefied gas (13) in the liquefied gas reservoir (6) is located between the upper end and the lower end of the liquid / gas heating pipe (8), and as a whole, the reservoir ( Since the evaporator (15) is disposed below the evaporator (6), the liquefied gas (13) freely falls from the storage chamber (6) to the lower end of the evaporator (15). Then, it enters the inside of the liquid / gas heating pipe (8) (see FIG. 2). Also,
A heating medium (14) passes from the top to the bottom outside the liquid / gas heating tube (8). The movement of the heat medium (14) is generated by being heated by the heater (16), and is natural convection by being cooled by the evaporator (15), and is caused by a so-called thermosiphon. The liquefied gas (13) in the liquefied / gas heating pipe (8) is evaporated by the heat medium (14) flowing from the top to the bottom in the evaporator (15), and ascends as shown in FIG. ). This heating gas (9) rises in the support insulator (2) and rises in the cutoff (1). At this time, the heating / cooling gas mixture state (12) is raised with the surrounding cold gas and rises. As the liquefied gas (13) in the liquid / gas heating pipe (8) evaporates, the liquefied gas naturally flows in from the storage chamber (6) and circulates naturally by the heat source pump without a forced drive pump.

As the amount of heat injected by the heat source (17) increases, the action of the heat source pump becomes stronger, and the level of the second level gauge (20) becomes lower than the level of the first level gauge (19). Therefore, if the amount of injected heat is controlled in consideration of the first liquid level gauge (19) and the second liquid level gauge (20), the heat source pump is optimal for the gas condensed amount. Incidentally, the gas gate valve (10) is a valve for repair, and the gas intake / discharge valve (21) sucks and discharges gas during repair.

Although the above embodiment has shown the prevention of gas liquefaction of the circuit breaker, it can be applied to a gas bushing (a bushing structure product having no interruption portion), an interruption path, and other switching devices. To play.

[Effects of the Invention] As described above, according to the present invention, the liquefied gas is guided to the evaporator by free fall, and a heater using a thermosiphon is combined with the evaporator to make it possible to effectively use the heat source pump. In addition, the conventional gas circuit breaker device can be used at low cost even in extremely cold regions without drastically changing the gas circuit breaker device, and can easily perform maintenance (replacement of a heater, etc.).

[Brief description of the drawings]

FIG. 1 is a schematic view showing a gas liquefaction preventing device of a gas circuit breaker according to one embodiment of the present invention, FIG. 2 is a diagram showing a cross section of a liquid / gas heating pipe of FIG. 1, and FIG. It is a figure of a partial section showing the neighborhood of an operation rod of a circuit breaker. In the figure, (6) is a liquefied gas storage chamber, (8) is a liquid / gas heating pipe, (9) is a heated gas, (13) is a liquefied gas, (1)
4) is a heating medium, (15) is an evaporator, (16) is a heater, (17)
Is a heating source, (19) is a first level gauge, and (20) is a second level gauge. In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (1)

(57) [Claims] 1. A gas liquefaction prevention device for a gas circuit breaker arranged in a low temperature environment, wherein a liquefied gas storage chamber in which a liquefied gas flows and is accumulated is disposed below the gas circuit breaker. The liquefied gas storage chamber is provided with an inlet / outlet through which the liquefied gas flows out from below the liquid level of the liquefied gas stored in the gas storage chamber, and the gas that has been evaporated and returned to the original level flows in above the liquid level. And an evaporator connected to the inlet and outlet to form a closed circuit including a vertically disposed heat exchange passage, and a vertical separate parallel to the evaporator heat exchange passage. A gas liquefaction prevention device for a gas circuit breaker, comprising a heater including a passage for passing a heat medium through natural convection.