Tomoyuki Kumano

Energy Conversion From Fossil Fuel Into Spectral-Controlled Radiation for TPV by Super-Adiabatic Combustion in Porous Quartz Glass

Characteristics of energy conversion from fossil fuel into radiant energy in the energy-recirculated thermophotovoltaic (TPV) generation system with piled porous quartz glass plates have been investigated through numerical simulation. When the total thickness of the quartz glass plates is fixed, it is revealed that the conversion efficiency of the system does not almost depend on a combination of the number of the quartz glass plates and the individual thickness. However, the spectral efficiency with respect to the specific TPV cell may be improved as both the number of the quartz plates is larger and the individual thickness is smaller. As a result, it is suggested that the achievable total efficiency of the TPV system is expected to be over 15% under the condition that the emitter of the system is regarded as gray body and the total thickness of the quartz media is 30mm.Copyright

TPV Power Generation System using Super‐Adiabatic Combustion in Porous Quartz Glass

Electric power was obtained using the super‐adiabatic combustion TPV power generation system. In the system, a porous emitter made of alumina (Ceramic Foam) is installed at the middle. At both sides of the emitter, porous quartz glass plates with many pores are set up. A mixture of air and methane is introduced into the porous media, and flows uniformly across the cross section, where the flow direction changes regularly. Combustion occurs around the surface of the porous emitter. Through energy recirculation, the temperature of the emitter reaches about 1500K under the condition of the equivalence ratio of 0.2. Furthermore, the long‐wavelength components of the radiation emitted from the porous emitter are partially absorbed by the porous quartz glass, then, the short wavelength components are introduced into the TPV cell. Though the view factor was very small and there was multiple‐surface reflection by the quartz glass, we obtained the output power, which was small, using the super‐adiabatic combustion...

Energy Conversion from Fossil Fuel into Spectral-controlled Radiation for TPV by Super-Adiabatic Combustion

Characteristics of energy conversion from fossil fuel into radiant energy in the energy-recirculated thermophotovoltaic (TPV) generation system with specific porous quartz media such like piled porous quartz glass plates are investigated through numerical simulation. When the total thickness of the quartz media is fixed, the conversion efficiency of the system depends mainly on the design parameter of coefficient heat transfer and porosity for the porous quartz media. It is suggested that the achievable total efficiency of the TPV system is expected to be over 10% under the condition that the emitter of the system is regarded as gray body and the total thickness of the quartz media is 15mm.

A Feasibility Study on Spectral Control using Piled AR‐coated Quartz Filters for Application to TPV

Piled AR‐coated quartz filters enable to control spectral transmittance for diffuse irradiation without designing the complex multi‐layer coatings. In this study, spectral transmission characteristics of the piling quartz filters with simple double‐layer coat and the optimum condition for TPV application were investigated through Ray Tracing numerical simulation. As a result, it was revealed that the piled quartz filters was very useful to achieve good spectral performance in the ideal energy recirculated TPV system when the number of the filters was enough large and thickness of each filter was enough thin. Then, the achievable spectral efficiency in the TPV system can be expected to exceed 70%. In the filtering method, the most striking feature is that the spectral efficiency can be controlled flexibly by changing the number of the filters and the individual thickness according to the situation.

Spectral Control of Transmission of Diffuse Irradiation using Piled AR Coated Quartz Glass Filters

Spectral transmission characteristics of piled quartz glass filters with anti‐reflection (AR) coating and without coating were investigated for diffuse irradiation through ray tracing numerical simulation. The spectral transmittance for diffuse irradiation is lower than that for normal irradiation because surface reflection becomes large with increasing incident zenith angle. By using the AR coating, the transmittance for diffuse irradiation becomes much higher than that without coating around a wavelength of 1.1 μm that is specified for the coating thickness design. On the other hand, for the long wavelength region, the transmittance reduced largely due to multiple‐surface and absorption. The most striking feature is that difference between transmittances for the specified and the long wavelength region is enhanced using the piled AR coated quartz glass filters. If the refractive index of the coating material were 1.19, which was an ideal value for the design of the coating, the effect is the most remark...