Sulfur hexafluoride high-voltage circuit breaker for cold region

Abstract

The invention relates to a sulfur hexafluoride high-voltage circuit breaker. The sulfur hexafluoride high-voltage circuit breaker for a cold region comprises a device body of the high-voltage circuit breaker. A sulfur hexafluoride gas chamber, a density relay and a transmission mechanism are arranged inside the device body. Sulfur hexafluoride gas is filled inside the sulfur hexafluoride gas chamber, the high-voltage circuit breaker further comprises a sulfur hexafluoride gas liquefying prevention device. The sulfur hexafluoride gas liquefying prevention device comprises a gas storage tank filled with the sulfur hexafluoride gas and a connecting pipe. One end of the connecting pipe is connected on a gas compensation port or a special connecting port of a high-voltage circuit breaker body in a sealing mode, and the other end of the connecting pipe is connected on the gas storage tank to enable the inside of the gas storage tank and the sulfur hexafluoride gas chamber to be mutually communicated, and a thermal insulating layer is arranged outside the gas storage tank. The sulfur hexafluoride high-voltage circuit breaker can prevent the sulfur hexafluoride gas from being liquefied or liquefied too much, and the safe operation of the sulfur hexafluoride high-voltage circuit breaker in cold weather can be guaranteed.

Description

technical field [0001] The invention relates to high-voltage electrical equipment, in particular to a sulfur hexafluoride high-voltage circuit breaker. Background technique [0002] Because sulfur hexafluoride gas has excellent insulation and arc extinguishing properties, it is an ideal insulation and arc extinguishing medium in high-voltage circuit breakers, and has been widely used at home and abroad. The excellent performance of sulfur hexafluoride gas is realized at a certain density and pressure. When the temperature drops to a certain level, the sulfur hexafluoride gas inside the high-voltage circuit breaker will liquefy, and its liquefaction temperature is related to density and pressure. The greater the density, the higher the liquefaction temperature. Due to the liquefaction of sulfur hexafluoride gas inside the high-voltage circuit breaker, part of the gas becomes liquid, the density and pressure of sulfur hexafluoride gas will gradually decrease, which will c...

AI Technical Summary

Problems solved by technology

[0005] 1. Use mixed gas (sulfur hexafluoride / N 2 ; Sulfur hexafluoride / CF4, etc.) as an arc extinguishing and insulating medium, its disadvantages are: the breaking power capacity of high-voltage circuit breakers is only about 80% of the original, and the manufacturing technology requirements are high and the cost is expensive; the proportion of mixed gas The mixing method requires a reasonable ratio, otherwise the insulating properties and arc extinguishing properties of the mixed gas will be severely weakened. At the same time, once the gas leaks, but because the two high-pressure gases are mixed together, the leakage rate is different, and the supplementary gas process is very complicated. Failure to meet the technical requirements of the product has brought a lot of inconvenience to the use, testing and management of the product, so it cannot be promoted

[0006] 2. Reduce the pressure of sulfur hexafluoride to reduce the liquefaction point of sulfur hexafluoride gas. However, due to the reduction of gas pressure, the gas density also decreases, resulting in a decrease in the arc extinguishing performance and insulation performance of high-voltage circuit breakers.

The disadvantage of this method is: since the sulfur hexafluoride gas of the tank-type sulfur hexafluoride circuit breaker is well sealed in the tank, it can only be heated by heat conduction, the structure is complex, and the thermal efficiency is low. Direct heating will also accelerate the aging of the sealing ring of the tank-type sulfur hexafluoride circuit breaker, causing air leakage and serious safety problems; The following measures are taken: that is, a heater is installed inside or outside the sulfur hexafluoride gas chamber of the high-voltage circuit breaker, and is automatically controlled by an intelligent temperature controller. When the ambient temperature drops below a certain temperature, the thermostat turns on the power supply of the heater Heating the sulfur hexafluoride gas chamber to keep the temperature of the sulfur hexafluoride gas chamber above a certain temperature

[0009] To sum up, the current SF6 high-voltage circuit breaker has the problem of liquefaction of SF6 gas when operating in cold regions, which brings hidden dangers to the safe operation of the power grid.

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