典型特高压换流变压器火灾数值模拟研究

通过文献调研及事故资料分析，阐释了特高压换流变压器的结构特点和事故工况。采用CFD 数值模拟技术，根据典型事故工况的油料状态、边界条件和环境条件等，设计5 个工况，研究典型特高压换流站变压器火灾的发生和发展过程。分析典型变压器火灾的燃烧形式、热释放速率大小及火源周边温度特性等，获得阀厅外壁面温度对阀厅的影响。设计可脱落式Boxin顶板时，应考虑其在火灾过程初期温度上升较慢、温度较低的特点。为创造换流变火源窒息熄灭的有利条件，应保证阀厅封堵及顶部Box-in 降噪板不受破坏，火灾时主动封闭下3 行散热风扇，阻止空气流入；阀厅封堵破坏时，可以将换流变压器正面散热风扇洞口全部封闭，阻止空气进入。

Numerical simulation study on fire of typical UHV converter transformer

Based on literature review and analysis of accident data,the structural characteristics and accident conditions of UHV converter transformer were elaborated. By means of CFD numerical simulation, according to the oil states, boundary conditions and environmental conditions of typical accident conditions, the occurrence and development process of transformer fire in typical UHV converter station were studied based on 5 scenarios. The combustion form, heat release rate and temperature around fire source of typical transformer fire were analyzed. The influence of the temperature of the outer wall of the valve chamber on the valve chamber were obtained. The characteristics of slow temperature rise and low temperature in the early stage of fire should be considered during the design of the detachable Box- in roof. In order to create favorable conditions for the extinction of the converter fire source,the sealing of the valve hall and the Box- in noise reduction plate should not be damaged at fire, and the lower 3 rows of cooling fans should be closed actively to prevent air from flowing in. The front cooling fan hole of the converter should be completely closed to prevent air from entering when the valve hall plugging is damaged.