环境因素影响下GIL温升特性的仿真计算分析

为研究不同环境因素对架空敷设式气体绝缘金属封闭输电线路(GIL)温升特性的影响,建立电磁场-热场-流场多物理场耦合计算模型,进而分析了不同环境因素影响下GIL外壳和导体温度变化特征、外壳外表面的对流换热系数变化及不同负载GIL温升受环境因素影响的差异性。结果表明:风速与GIL温降的关系是非线性的,风速在0～3 m/s时,外壳和导体的温度下降较快,当风速高于3 m/s时,外壳和导体温度随风速增加下降速度越来越小,最终导体温度趋于稳定值,外壳温度逐渐接近于环境温度,当风速相同时,GIL负荷电流越大,导体和外壳温降速度越大;太阳辐射强度对GIL温升的影响基本呈线性关系,且太阳辐射强度对外壳温升的影响更明显,太阳辐射强度相同时,导体和外壳的温升差随负载电流的增加而减小;导体和外壳温度与环境温度基本呈等斜率线性关系。

Simulation and analysis of GIL temperature rise characteristics under effects of environmental factors

In order to study the influence of different environmental factors on temperature rise characteristics of overhead GIL(Gas-Insulated metal enclosed transmission Line),an electromagnetic-thermal-flow coupling model is established, with which, the temperature variation characteristics of GIL shell and conductor, the convective heat transfer coefficient of shell surface and the difference of GIL temperature rise under different environmental factors are analyzed. The results show: the relationship between wind speed and GIL temperature drop is non-linear; if wind speed is in the interval of 0 to 3 m/s, the temperature of shell and conductor decreases rapidly; when wind speed is bigger than 3 m/s, the temperature decrease of shell and conductor becomes smaller along with the increase of wind speed, and finally keeps a stable value, the shell temperature is gradually close to the environmental temperature; when wind speed is the same, the bigger GIL load current is, the greater conductor and shell temperature drops; the effect of solar radiation intensity on GIL temperature rise is basically linear and more obvious on temperature rise of shell; under the same solar radiation intensity, the difference of temperature rise between conductor and shell decreases along with the increase of load current; the temperature of conductor and shell is basically linear with the environmental temperature.