Abstract :
THERMOSIPHON COOLING of oil-immersed transformers has been in use for many years, and cooling tubes and radiators in standard configuration may be applied to transformers with confidence. In the development of new cooling equipment, however, the performance and efficiency of new shapes and arrangements are determined empirically. The theoretical analysis of thermosiphon flow is quite complicated. Actually, although it may be used qualitatively in many cases, the theoretical approach is directly applicable only to idealized circuits, and the basic assumptions concerning modes of flow, for example, must be checked experimentally.