Thermophotovoltaic Emitter Material Selection and Design
Abstract
Direct energy conversion is an attractive option for the Navy because it eliminates the need for complex machinery and reduces maintenance concerns by eliminating moving parts. Thermophotovoltaic (TPV) generators offer all of the advantages of direct energy conversion, and can be run from waste heat. Current TPV generators are either inefficient or impractical. The focus of this research is to further technical understanding of the material issues involved in designing a TPV generator. Much like a solar power system, TPV generators use photocells to collect radiant energy and produce electric power. In this system, radiation is collected from a high temperature emitter material which emits photons with a wide spectrum of energies, the peak in the spectrum being directly related to the material temperature. Current TPV cell technology dictates that the emitter material needs to withstand 1300 deg. C in a combustion gas atmosphere and achieve an emissivity of at least 0.90. Initial material screening included ceramics, refractories, metallics, and ceramic matrix composites. Candidate materials were selected based on available published data. Thermal shock and oxidation experiments were conducted, and materials were evaluated for emissivity in conjunction with NASA Lewis Research Center. Machinability, thermal conductivity, and thermal expansion properties were also considered. The most viable emitter candidates were determined to be C/SiC with a SiC overcoat and SiC/Si.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 07, 1997
- Accession Number
- ADA418470
Entities
People
- Patrick C. Saxton
Organizations
- United States Naval Academy