Completion of high-efficiency water pipe cooling system for underground transmission line

An advanced, high-efficient, forced cooling system was developed and employed for a bulk power underground transmission cable line called Nankou-Karyoku Line. A principal feature of this system is an efficient computer-controlled operation method of cooling equipment to reduce the running cost of the equipment by optimizing the cooling rate according to load changes of the cable line. This paper introduces an actual performance of the cooling operation measured and evaluated on the cable line, as well as the outline of the cooling system. KEYWORD - Indirect Forced Cooling; Water Pipe Cooling in Tunnel; Cooling System;