Kenji Watanabe, Atsushi Kimura, Kenya Kawabata, Tomoki Yanagida, Mamoru Yamauchi
In order to reduce the cost of electric power, efforts have been made to increase utilization efficiency by means of load leveling. One way of accomplishing this is with sodium-sulfur (NAS) batteries, but for these to provide stable long-term service, a temperature control mechanism that operates at high temperatures is required. The variable-conductance heat-pipe (VCHP) described here meets this need. Unlike conventional heat-pipes the VCHP is controllable, and its heat-radiating structure requires no external power source or sensors, and has no moving parts. Installing VCHPs provides a level of heat control ample for the NAS battery, thereby contributing to improved charge/discharge efficiency. This paper describes a VCHP developed for high-temperature applications.