In the present study, the performance of a heat-recirculating combustor that was designed in the previous study for thermophotovoltaic (TPV) power devices in which thermal energy is directly converted into electrical energy through thermal radiation is investigated for a 10-30 W electrical power-generating TPV device. Performance of various types of emitters is evaluated by measuring temperature distribution on the emitter wall surface and the spectral emissive power density onto a spectrometer. Silicon carbide (SiC) and alumina (Al_2O_3) emitters are first considered, and to apply photonic crystal structure SiC and Al_2O_3 are considered as the emitter substrate. Each emitter substrate is simply wrapped by erbium oxide (Er_2O_3) powder. For the Al_2O_3 emitter, higher maximum and average temperatures on the emitter wall surface are observed compared with the SiC emitter. For the Er_2O_3-wrapped Al_2O_3 emitter the wrapping is well-maintained without any crack at high temperature. Also, higher spectral emissive power density is observed in the wavelength range from 800 to 1100 nm and from 1300 to 1800 nm. For the Er_2O_3-wrapped SiC emitter, however, the wrapping is cracked after several tests and spectral emissive power density is not significantly enhanced at the wavelengths of interest compared with the Er_2O_3-wrapped Al_2O_3 emitter.
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