New 5 Kilowatt Free Piston Stirling Space Convertor Developments
- Paper number
IAC-07-C3.2.07
- Author
Dr. Henry Brandhorst, Auburn University, United States
- Coauthor
Peter Chapman, United States
- Year
2007
- Abstract
The NASA Vision for Exploration of the moon envisions a nuclear reactor coupled with a free piston Stirling convertor at a power level of about 30 kW. In the 1990s, NASA developed a 25 kW free piston Stirling Space Power Demonstrator Engine for the SP-100 program. This system consisted of two 12.5 kW engines connected at their hot ends and mounted in a linear arrangement to cancel vibration. It operated successfully for 1500 hours. Since that time, NASA and DoE have been developing the Stirling Radioisotope Generator (SRG110) – dual 55 W Stirling convertor systems for use with radioisotope heat sources. Test times over 20,000 hrs have been accumulated on the one set of engines and total operation times of all the convertors totals over 105,000 hours. The program was recently changed to the Advanced Stirling Radioisotope Generator system with hermetically-sealed 80 W convertors. These convertors are being tested and are showing excellent performance and reliability. However, these smaller units are not suitable for a surface nuclear reactor application because studies project the power level to be around 25-30 kW. Thus a larger convertor is needed as well as “assumed” reference requirements defined in preparation for development of a 5 kW free piston Stirling conversion system for such a reactor power systems. A 5 kW single piston convertor allows two of these units to be operated in tandem to eliminate vibration. A group of three dual-convertor combinations would yield the desired 30 kW. Goals of this development program include a specific power in excess of 140 W/kg at the convertor level, lifetime in excess of five years and a control system that will safely manage the convertors in case of an emergency. Auburn University has awarded a contract to Foster-Miller, Inc. to undertake development of this single 5 kW Stirling Convertor Assembly. The characteristics of the design will be described along with progress in developing the system. Other testing results of a 1-3 kW terrestrial system will also be described. A 1 kW system heated with propane has been in operation at Auburn for two years and this system will be expanded to obtain results at higher power levels. This system has also operated without any problems from the free piston Stirling convertor. The results of both laboratory testing of the existing unit and progress in design, fabrication and component testing of the new 5 kW assembly will be presented.
- Abstract document
- Manuscript document
IAC-07-C3.2.07.pdf (🔒 authorized access only).
To get the manuscript, please contact IAF Secretariat.