| 摘要 |
PURPOSE:To contrive imoprovement in long-term or short-term cooling reliability and cooling efficiency at the time when the title transformer is overloaded by a method wherein the flow of refrigerant in each cooling panel built-in in a winding is brought to a controllable state. CONSTITUTION:Flow rate adjusting valves 23 are attached to a part in the middle of each insulated pipe 12 located on the flow-out side of cooling panels 6a-6d. The main body of said flow-rate adjusting valve 23 is formed with a shape memory alloy which is operated based on the temperature of a refrigerant, and when the refrigerate reached the stabilized set value, the shape memory alloy is deformed, and a flow-rate adjustment is performed automatically. The flow rate of refrigerant flowing to each of cooling panels 6a-6d built-in in a winding can be controlled by the maximum temperature of the winding and the temperature of the refrigerant. As a result, the flow of refrigerant can be adjusted immediately to the optimum flow rate automatically even when a change is generated in fludization characteristics caused by the deterioration of the refrigerant by the long-term operation of the transformer, the leakage of the liquid refrigerant and the like. |
