Tungsten Copper for Switch
The circuit breaker is one of the systems the most important of the high-pressure equipment. When systems failure, to trip the circuit breaker protection devices excision of failure to maintain system stability. The circuit breaker in accordance with its interrupter media sub-divided into the oil circuit breakers, compressed air circuit breakers, vacuum circuit breakers and SF6 circuit breakers. Oil circuit breaker is divided into two types of oil and less oil. Products are eliminated more oil has basically not used; less oil circuit breaker is not to say that in our country there is a certain range of applications, but this performance is very good, but relative to the same voltage level of vacuum its cheaper price and s breaker can basically meet the requirements, the specific use down. Oil circuit breaker has a fatal flaw, it is in the long-running the insulating oil prone carbonation phenomenon, especially in the case of a short time repeated resection failure are more likely to insulating oil carbonization, which will greatly reduce its ability to interrupter. The second is the maintenance workload, maintenance interval shorter in the new project is not recommended to use.
Compressed air circuit breaker must be equipped with a compressed air device, relying on compressed gas interrupter larger area and greater wear contacts, and therefore a very small range of applications. The vacuum circuit breaker is a vacuum (pressure of l0 ~ l0-6 Pa) to the interrupter of a circuit breaker, the contact is mounted in the vacuum interrupter chamber. Since there is almost no free gas in the vacuum, therefore, when such contacts of the circuit breaker in the disconnected only emitted because of the high electric field, and the thermoelectric emission produces little vacuum arc so that it can in the first current zero crossing off, so that both ensures that the interrupter can be within a very short time, but not so in the system to produce a high pressure changes due to the Shaanxi speed current. Vacuum circuit breaker has small size, light weight, fast action, long service life, high security and reliability, and eases of maintenance overhaul many advantages, but the price is more expensive than oil circuit breaker. SF6 Circuit Breaker is the use of a circuit breaker of the SF6 gas as the insulating and arc extinguishing medium, s is a colorless, odorless, non-toxic and flammable gases, its chemical properties are fairly stable below 150 ℃, although at a high temperature will break down to produce toxic gas interrupter state, and will produce a small amount of the active substance, but through the use of the adsorbent and the contact has a self-cleaning function, equipment and personal will not cause harm.
SF6 breaker roughly experienced three stages: the double pressure of a single-pressure thermal expansion, thermal expansion is the development direction of the current and future period. SF6 does not contain the oxygen element, and therefore does not oxidize at high temperatures also contacts, it is not the element carbon, so maintenance more convenient, and can be done almost maintenance-free. The SF6 insulating properties and dielectric strength of the insulating oil is roughly 3 atm. particularly advantageous that the SF6 gas having a rapid recovery of the dielectric strength characteristics, which makes it possible within a very short period of time to extinguish the arc. SF6 circuit breakers and oil circuit breaker interrupter speed, breaking capacity, good electrical insulation properties, long servicing intervals. S circuit breaker is now a major component of GIS (enclosed Switchgear), in a certain period of time, the application prospect is considerable. 2 the development of domestic and foreign high-voltage electrical switches.
Tungsten copper alloy in the aerospace used as a missile, rocket engine nozzle vane air rudder, the nose cone, the main requirement is to require high temperature (3000K to 5000K), high temperature airflow flushing capacity, using mainly copper at high temperatures. The volatiles formed diaphoretic refrigeration (copper melting point 1083 ° C), to reduce the surface temperature of the copper tungsten, use in high temperature and under extreme conditions.