Calculation Approach for Ceramic Heat Pipe Heat Exchangers for High-Temperature Applications

Metal materials show poor lifetime behavior under high-temperature conditions and aggressive atmospheres. An alternative solution is the use of ceramic material, e.g., silicon carbide ceramics. These ceramics cannot be processed and joined like metal materials. For this reason, the simple geometry of a heat pipe can be used as a basic design for ceramic heat exchanger systems in the high-temperature process technology for industrial and power plant applications. Heat pipes are hermetically sealed tubes filled with a working fluid. By transferring heat to one side and by releasing heat from the other side a two-phase cycle is set up. For these apparatuses a numerical calculation model for a more exact determination of the working behavior of large units under high-temperature conditions is introduced, considering both convective and radiative heat transfer.