Thermionic energy conversion (TEC) topping thermoelectrics [electronic resource].
- Published:
- Cleveland, Ohio : Lewis Research Center, 1981.
Oak Ridge, Tenn. : Distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy. - Physical Description:
- Pages: 17 : digital, PDF file
- Additional Creators:
- Lewis Research Center and United States. Department of Energy. Office of Scientific and Technical Information
Access Online
- Restrictions on Access:
- Free-to-read Unrestricted online access
- Summary:
- Long-respected international experts on thermoelectrics (Dixon, Ertl and Goldsmid supported by Ure) determine the probable maximum figure of merit (ZT) for fully matured thermoelectric generators as about unity from ordiary temperatures to 2000 K. Thus the maximum efficiency for fully matured thermoelectrics would be approximately 0.414 (l - r/sub T/)/(1.414 + r/sub T/) where r/sub T/ is the ratio of cold and hot junction temperatures. This limitation contrasts with the recent burst of enthusiasm for high-temperature thermoelectrics - based on calculated figures of merit and efficiencies that increase more and more rapidly with rising temperatures. Unfortunately these calculations neglect internal radiation effects which diminish thermoelectric figures of merit significantly at 1000 K and substantially at 2000 K: The effective thermal-conductivity contribution of intrathermoelectric radiative dissipation increases with the third power of temperature. Therefore the quotation from Thermoelectricy: Science and Engineering by Heikes and Ure apparently still prevails: ...thermoelectric devices appear difficult to extend in the direction of high temperature, while thermionic devices become inefficient at low temperature. Accordingly consideration of thermoelectric power generation with high-temperature heat sources should include utilization of TEC topping thermoelectrics. However TEC alone or TEC topping more-efficient conversion systems like steam or gas turbines, combined cycles or Stirling engines would be more desirable generally.
- Report Numbers:
- E 1.99:doe/nasa/1062-8
E 1.99: nasa-tm-81677
E 1.99: conf-810527-1
conf-810527-1
nasa-tm-81677
doe/nasa/1062-8 - Subject(s):
- Other Subject(s):
- Combined-Cycle Power Plants
- Topping Cycles
- Thermionic Converters
- Thermoelectric Generators
- Efficiency
- Bottoming Cycles
- Cost
- Gas Turbines
- High Temperature
- Performance
- Power Density
- Power Generation
- Radiant Heat Transfer
- Stirling Engines
- Temperature Dependence
- Very High Temperature
- Direct Energy Converters
- Energy Transfer
- Engines
- Heat Engines
- Heat Transfer
- Machinery
- Power Plants
- Thermal Power Plants
- Thermodynamic Cycles
- Turbines
- Turbomachinery
- Nesdps Office Of Nuclear Energy Space And Defense Power Systems
- Note:
- Published through SciTech Connect.
01/01/1981.
"doe/nasa/1062-8"
" nasa-tm-81677"
" conf-810527-1"
International conference on plasma science, Sante Fe, NM, USA, 18 May 1981.
Morris, J.F. - Funding Information:
- AI01-77ET13111
View MARC record | catkey: 14068611