Dynamic characteristics of heat pipes
Abstract
The dynamic response of a heat pipe at start-up or variable thermal input under buffered conditions relates to various properties of the working fluid. Both water and sodium charged heat pipes were tested with air and helium buffering, respectively. The experimental determination of dynamic response of each heat pipe, under varying operating conditions, was compared to theoretical predictions. The sodium heat pipe was heated by a fluidized bed combustion system since the study was aimed at establishing the start-up time for a fluidized bed/heat pipe energized Stirling engine under development. Problems associated with high rates of extraction of heat from a fluidized bed, by use of heat pipes, create the basic problem of maximizing surface to volume ratio for heat transfer. This is seen to involve the use of multi-limb heat pipe design. Tests were undertaken to establish the difference in start-up conditions of multi-limb thermosiphon and heat pipe designs. The apparatus was constructed in glass, with acetone as the working fluid, to allow for visual observation to determine the influence of variable thermal input to the limbs on migration of the working fluid.
- Publication:
-
Heat Pipes
- Pub Date:
- 1976
- Bibcode:
- 1976hepi.rept..153R
- Keywords:
-
- Air;
- Dynamic Response;
- Heat Pipes;
- Sodium;
- Water;
- Buffers (Chemistry);
- Fluidized Bed Processors;
- Heat Transfer;
- Performance Tests;
- Starting;
- Stirling Cycle;
- Stirling Engines;
- Thermosiphons;
- Wicks;
- Working Fluids;
- Fluid Mechanics and Heat Transfer