大变压器线圈典型油道分流合流阻力特性

本文以25~＃变压器油为工作介质,对狭缝状直角三通进行了阻力特性的实验研究,按分流合流的四种模态,在流量比依次为1,2,3,4和5,通道截面比依次为1,1.2,1.4,1.6,1.8和2的条件下,按各种组合进行了实验,并就此进行分析讨论,导出了各种模态下的经验公式.

The Drag Behavior of Diffluent and Confluent Oil Flow along Typical Oil Channels in Large Transformers

An experimental study of the drag behavior in narrow right-angle tee with No. 25 transformer oil as the working medium is reported. Various combinations have been made, including four flow models, five oil flux ratios and six channel cross-sectional area ratios. Experimental results show that the drag coefficient varies with flux ratios and area ratios, but the effect of the area ratio is relatively small. In a diffluent oil flow, the drag coefficients of bent channels increase with the flux ratio. In a confluent oil flow, however, the situation is much more complicated. The drag coefficients are much smaller in straight channels than those in bent ones. It is quite obvious that the drag coefficients in straight channels decrease with an increase of the flux ratio no matter the flow is diffluent or confluent. The total drag coefficients of both flows in a tee decrease as the Reynolds number Re increases. The total drag coefficients become stable soon with an increase of Re.