Circuit breaker as well as arc extinguishing chamber and nozzle thereof

Abstract

The invention discloses a circuit breaker as well as an arc extinguishing chamber and a nozzle thereof. The nozzle comprises a casing-like nozzle body, two ports of the nozzle body are respectively a gas inlet for charging arc extinguishing gas and a gas outlet for jetting the arc extinguishing gas, a throat narrower than the gas inlet and the gas outlet is formed in the nozzle body, the inner wall of the throat is an annular necking step convexly formed on the inner wall of the nozzle body, the necking step is provided with a bridge-type airflow hole, the inlet orifice of the airflow hole is located on the annular end face of the necking step facing the gas inlet, the outlet orifice of the airflow hole is located on the inner wall of the necking step, and the airflow hole is communicated with the throat and the gas inlet. The airflow hole in the necking step achieves the effect of enhancing the circulation performance of the throat, and at the moment when a static arc contact is separated from the throat, the arc extinguishing gas in the inlet of the nozzle can act on the end of the static arc contact via the airflow hole to enhance the blowing strength at the moment when the throat is separated from the static arc contact, so that the arc extinguishing effect is enhanced.

Description

technical field [0001] The invention relates to a circuit breaker and its arc extinguishing chamber and spout. Background technique [0002] At present, the 66 kV voltage level power grid is only distributed in the northeast region of China, and the annual domestic demand for 72.5 kV switchgear applied to this voltage level is not as huge as that of other voltage level products, so most switch manufacturers are not willing to invest A lot of resources are devoted to the development of products of this voltage level, and the switchgear of 126 kV voltage level is usually applied to 72.5 kV. For the manufacturing plant, it only reduces the R&D investment and management cost of the product, but in the long run, the consumption of materials and the pollution to the environment are undoubtedly not worth the candle. [0003] The most critical component circuit breakers in high-voltage switchgear currently mainly include sulfur hexafluoride circuit breakers and vacuum circuit break...

AI Technical Summary

Problems solved by technology

For the manufacturer, it only reduces the R&D investment and management cost of the product, but in the long run, the consumption of materials and the pollution of the environment are undoubtedly not worth the candle.

[0003] The most critical component circuit breakers in high-voltage switchgear currently mainly include sulfur hexafluoride circuit breakers and vacuum circuit breakers. At present, the insulation strength of 72.5kV vacuum circuit breakers in the process of breaking large currents and small currents, and the rated current The problem of temperature rise during flow still needs to be improved due to immature technology, so most manufacturers at home and abroad use SF6 circuit breakers to bid

Among similar products at home and abroad, the rated inflation pressure of SF6 is mostly above 0.5MPa, and the liquefaction pressure of the gas is relatively high, which is not conducive to the use in the low-temperature environment in Northeast China; at the same time, the amount of greenhouse effect SF6 gas is large, the environmental friendliness is poor, and the cost of gas use is high; The moving part of the product is in a high-pressure interrupter environment, the instantaneous damping at startup increases, the required operating work increases, and the burden on the strength design and reliability design of the structural parts is increased, which virtually increases the cost of materials and also increases the energy consumption

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