不同环境下特高压主变压器火灾蔓延特性研究

Study on the main transformer fire spread characteristics of ultrahigh voltage station under different environment conditions

特高压技术在远距离电力传输中扮演着重要的角色,但近年来特高压站变压器火灾频发、后果严重。针对不同环境风和防火墙设置条件,对特高压主变压器火灾的蔓延特性开展了研究,探讨了环境风和防火墙耦合条件下温度场和热辐射分布规律。研究结果表明:无风条件下主变压器在着火150 s左右达到最大热释放速率70 MW左右,火灾增长速率系数可达3.11,属于超快速火范畴;下风向防火墙失效、环境风增大时,下风向相邻变压器被引燃的风险增大;上风向防火墙失效、环境风增大时,下风向防火墙上方温度升高;当风速为2 m/s时,温度可达150℃,引燃防火墙上部物质的风险增大。同时对主变上方线缆高度处(14 m高度)温度分布规律进行了分析总结,结果可为线缆及构架防火保护提供理论依据。

Ultra-high voltage(UHV)technology plays an important role in long-distance power transmission,but in recent years,transformer fires in ultra-high voltage substation occur frequently,resulting in serious consequences.For different environmental wind and firewall setting conditions,the fire spreading characteristics of UHV main transformer are studied,and the temperature field and thermal radiation distribution laws under the coupling conditions of ambient wind and firewall are discussed.The results show that the maximum heat release rate of the main transformer is about 70 MW at 150 s after ignition,and the fire growth rate coefficient can reach 3.11,which belongs to the category of ultra-fast fire.If the downwind firewall fails,the greater the ambient wind,the greater the risk that the downwind adjacent transformer will be ignited.If the upwind firewall fails,the greater the ambient wind,the higher the temperature above the downwind firewall.When the wind speed is 2 m/s,the temperature can reach 150℃,and the risk of ignition of substances above the firewall increases.In addition,this paper also analyzes and summarizes the temperature distribution law at the cable height(14 meters above the ground)above the main transformer.The results can provide a theoretical basis for the fire protection of the cable and the structure.