Flow Rate Distribution between Windings in a Self-Cooled Transformer

Abstract

The flow rate in a self-cooled transformer was difficult to be measured, because the driving force of the oil flow is very small. By this reason the characteristics of the flow rate distribution between windings have not been made clear. But by using the laser doppler velocimeter we now can measure this flow rate. Authors made the basic model which has vertical flat plate heaters and the larger scale disc winding model. The flow rate distributions between windings of these models are measured. On the other hand the flow rate distribution is calculated by using thermosiphone flow principle. The calculated value is compared with the measured value and both agree fairly well in heat flux range under which real transformer works. Then the characteristics of the flow rate distribution are made clear by using this calculation.