Ceramic Heat Pipes for High Temperature Application

High temperature heat pipes with a ceramic container consisting out of sintered silicon carbide (SSiC) and with zinc as working fluid are investigated. To summarize the results, the performance of a singular bench-scale ceramic heat pipe (length 1,070 mm, outer diameter 22 mm) can achieve up to more than 1,000 W under test conditions. The best performance is reached with a filling amount of 100 g zinc as working fluid, which comes up to a filling height of about 11% of the total heat pipe length under liquid conditions. The present operating temperature of the heat pipes on the heating gas side could be tested up to 980 degrees C, so that the temperature inside the heat pipe, which is equal to the boiling temperature of the working fluid, has to be a little bit lower than that point. The pressure inside the heat pipe is beneath the ambient pressure at up to 907 degrees C working fluid temperature. (C) 2017 The Authors. Published by Elsevier Ltd.