Reliability of low-cost liquid metal heat pipes
Abstract
Low-cost stainless steel heat pipes containing sodium or potassium working fluids have been proven to have long-term reliability. Heat pipes fabricated from 304 stainless steel with wicks of the same material have exhibited over 10,000 hours of reliable operation at 600 C (potassium) and 700 C (sodium) in ambient environments. Temperature stability was maintained to within 5 C over the test period. Extensive metallurgical analyses of inner and outer surfaces of the heat pipes and of the wicks have shown only minor amounts of material transport and of leaching from inner surfaces. External oxidation was negligible and there were no indications of electrolytic corrosion. The depth of inner surface attack was only 0.001 to 0.003 cm in thickness after 10,000 hours of operation. From this information lifetimes in excess of 50,000 hours can be reliably predicted.
- Publication:
-
3rd International Heat Pipe Conference
- Pub Date:
- 1978
- Bibcode:
- 1978ihp..conf..297E
- Keywords:
-
- Heat Pipes;
- Liquid Metals;
- Low Cost;
- Performance Tests;
- Reliability Engineering;
- Stainless Steels;
- Cost Reduction;
- Electrochemical Corrosion;
- Environmental Tests;
- Microstructure;
- Oxidation Resistance;
- Sodium;
- Thermal Stability;
- Working Fluids;
- X Ray Spectra;
- Fluid Mechanics and Heat Transfer