c-C_4F_8及其与N_2混合气体传热性能研究

Study on Cooling Performances of c-C_4F_8 and Its Mixtures with N_2 in GIL Model

氟碳气体c-C_4F_8温室效应小,耐电强度高,是一种良好的SF_6替代气体。使用氟碳气体与N_2的混合气体作为绝缘介质的气体绝缘开关,将成为一类新型的环境友好的设备。文中以管道输电模型为研究平台,通过散热分析结合实验测量的方法研究了0.1、0.25 MPa两种气压下氟碳气体、20%氟碳气体与80%N_2混合气体的散热性能并与N_2、SF_6散热性能进行比较。结果显示对于同一气体介质气压升高,气体综合传热系数增大,传热性能变好;对于不同的气体介质,气体综合传热系数大小排序有:SF_6≈c-C_4F_8>c-C_4F_8/N_2>N_2,但在管道输电模型下不同气体综合传热系数的差别对传热总量的影响较小,因而可认为这几种气体的传热性能相差不大。

Owing to its low global warming potential （GWP） and high dielectric performance, fluorocarbon gas c- C4F8 is a potential substitute for SF6 Gas insulated switchgear filled with c-C4F8/N2 gas mixture will become a new type of environmentally-friendly equipment. With a combination of heat transfer analysis and experimental measurement, the cooling performances of fluorocarbon gas and its mixture with N2 at pressures of 0.1 MPa and 0.25 MPa has been studied using a gas-insulated transmission line（GIL） and the results are compared with those of N2 and SF6 gas. Results show that the equivalent heat transfer coefficient of the same gas increases with pressure while for different gases we have SF6≈c-C4F8〉c-C4F8/N2〉N2.However, the effect of heat transfer coefficient is nonsignificant to the overall rate of heat loss. The cooling performance of the above mentioned gases is similar.