Other
Scientific paper
Jan 2006
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2006aipc..813..573m&link_type=abstract
SPACE TECH.& APPLIC.INT.FORUM-STAIF 2006: 10th Conf Thermophys Applic Microgravity; 23rd Symp Space Nucl Pwr & Propulsion; 4th C
Other
Thermoelectric, Electrogasdynamic And Other Direct Energy Conversion, Spaceborne And Space Research Instruments, Apparatus, And Components
Scientific paper
This paper reports on Phase 1 of a multifaceted effort to develop a more efficient radioisotope thermoelectric generator (RTG) for future NASA missions. The conversion efficiency goal is 10% or higher at a power level of 20 watt or higher. The thermoelectric (T/E) efficiency achievable with present T/E materials is about 8% for favorable temperatures. Thermoelectric converter designs, T/E material properties, and T/E couple thermal and electrical performance were investigated in Phase 1 of this program to find paths to improve conversion efficiency. T/E properties can be improved by optimizing the composition of the materials and by improving the micro structural characteristics such as homogeneity, grain size, and phases present. T/E couple performance can be improved by reducing the electrical and thermal contact resistances of the couple and within the segmented T/E elements. Performance and reliability improvements can be achieved by reducing the thermo-mechanical stresses, improving the quality of the bonds and interfaces, minimizing the number of required bonds, and reducing the degradation rates of both the T/E materials and the bonds. This paper focuses on one portion of the activity, i.e., the design of a small converter. In the converter design effort, a prototypic 20-watt device, suitable for use with a single general-purpose heat source (GPHS), was built using an optimized converter design of segmented thermoelectric elements of heritage composition. The 20-watt prototype achieved the power predicted for the test conditions. The chosen couple design used segmented BiTe/PbTe for the n-type element and BiTe/TAGS/PbSnTe, for the p-type T/E element. Use of the BiTe segment exploits the opportunity of the small RTG to operate at lower heat rejection temperatures and results in much higher conversion efficiency, the main objective of the NASA program. Long term data on similarly segmented couples at Teledyne together with the 20-watt module test results confirm that a small RTE based on a single GPHS and heritage materials can now reach a high readiness level, without need of material improvement. It is also anticipated that a more efficient version will be developed in the future that will also incorporate the material and process improvements identified in this phase.
Cummer Keith
McAlonan Malachy
Patel Kalpesh
No associations
LandOfFree
Radioisotope Thermoelectric Generators Based on Segmented BiTe/PbTe-BiTe/TAGS/PbSnTe does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Radioisotope Thermoelectric Generators Based on Segmented BiTe/PbTe-BiTe/TAGS/PbSnTe, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Radioisotope Thermoelectric Generators Based on Segmented BiTe/PbTe-BiTe/TAGS/PbSnTe will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1283556