| 摘要 |
PURPOSE:To arise and maintain appropriate ebullient condition by a method wherein a bubble generator preventing the abrupt ebullition of coolant is provided in a liquid coolant in a closed container. CONSTITUTION:The main body of an electrical machine 2 such as the main body of a transformer, for example, is accommodated in a closed container 1. An evaporative coolant 3 such as freon immersing the whole part of the main body of an electrical machine 2 is filled in this container 1. A cooler 6 is provided at the upper space 5 in the container 1. A bubble generator 7 such as a heater is provided at the vicinity of the main body of an electrical machine 2 and at the lower part of the closed container 1. The temperature of the coolant 3 increases up to near boiling temperature by the generation of heat from the main body of the electrical machine 2. A power is supplied to the bubble generator 7 before the ebullient temperature and bubble and vibration are provided for easy ebullition to prevent the coolant around an iron core 2a or the like from sudden ebullition by over heating. This prevents sudden ebullition and appropriate ebullient condition can be arisen and maintained. |
