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An Innovative Method for Hand Protection from Extreme Cold Using Heat Pipe

出版	United States Army Natick Research, Development and Engineering Center, Individual Protection Directorate, 1992
URL	http://books.google.com.hk/books?id=zOjUf2zdR7sC&hl=&source=gbs_api
EBook	FULL_PUBLIC_DOMAIN

註釋Due to the danger of frostbite at very low ambient temperatures, there is a need to develop new handwear technology to protect the fingers at temperatures down to about -80 deg F ( -62 deg C). The shortcomings of the existing technology, a glove with a heating element, are need for maintenance, size and limited capacity of the current batteries. An innovative method was investigated to transfer some of the body core thermal energy to the hands. This method involves the use of heat pipe technology, which has the advantages of very high effective heat conductivity, fast response time, flexibility low mass, compact size, and ease of maintenance. The design uses the person's elbow area as the heat source. The heat pipe extends along the arm and terminates at the surface of the back of the hand. From a simple model of the insulated arm and hand, the required heat transfer to the hand by the heat pipe to maintain a hand temperature of -81 deg F (27 deg C) with ambient temperature of -80 deg F 62 deg C) was shown to vary from 5.8 to 21 W for an insulation 'R' value from 0.741 to 0.185m 0 C/W. A very efficient and flexible heat pipe was developed and tested to show the feasibility of the use of heat pipe technology in the above application. Heat capacities between 1 and 5 W were measured, depending upon orientation with respect to gravity. Due to the necessity of transferring 1 to 5 times this amount of heat and to provide for more uniform heat distribution, these results indicate that multiple heat pipes may be required in the design of a handwear system.