Ceramic Heat Pipes for High Temperature Application
To summarize the results, the performance of a singular benchscale ceramic heat pipe (length 1070 mm, outer diameter 22 mm) can achieve up to more than 1000 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 fi lling height of about 11 % of the total heat pipe length under liquid conditions. The present oper ating temperature of the heat pipes on the heating gas side could be tested up to 980 °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 °C working fluid temperature.