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

An advanced, highly-efficient, forced cooling system was developed and employed for a bulk power underground transmission cable line called the Nankou-Karyoku Line. A principal feature of this system is efficient computer-controlled operation 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 the performance of the cooling operation measured and evaluated on the cable line, as well as an outline of the cooling system