Energy conversion systems and after treatment systems supported by nano/micro-scale phenomena

Transcription

1 Tokyo Tech-MIT Workshop 2015 Energy conversion systems and after treatment systems supported by nano/micro-scale phenomena Katsunori Hanamura Graduate School of Science and Engineering

2 Spectral Control of Emission of Radiation and TPV Generation of Electricity 2 Spectral Control by Microstructure Emitter (1000K) Nano-Gap GaSb TPV Cell(300K) Evanescent wave effect Burners Emitter Radiation GaSb Cell Electricity 1 mm Cavities on Ni Metal surface 2mm 2 Polished surface (1000K) Strong Electric Field 500nm Week Electric Field MBE System Spectral Control of near-field radiation Pillar Array structure TPV Cells for Generation of Electricity Spectral control of near-field radiation by pillar array structure SEM image of W pillar array

3 Heat loss by radiation in steel industry 3 Rotational furnace Cutting Continuous casting wiring Rolling

4 Exergy loss by hot water server 4 Exhaust gas (~50 ) out-flow energy <10% Water (~20 ) Hot water (~80 ) Energy conversion (>90% latent heat recovery) Exergy rate (<10%) Combustion gas (~2000 ) Exergy rate (~70%) City gas Exergy rate (~94%) Hot water maker Air blow fan

5 TPV Generation of Electricity by Radiation Surface Flame Burner 5 Power density: 0.3W/cm 2 Surface Temp.: 1000 Application to practical hot water server Surface Flame Burner Thermo-couple Thermo-couple 2 st Exch. Cooling water outlet 1 st Exch. City Gas Thermo-couple for TPV Burner Fan Burner Fan Air Thermo-couple Cooling water inlet In Out No.24 Hot Water Server Gap between burner and TPV cell

6 Thermophotovoltaic Generation of Electricity 6 - using propagating and near-field radiation - Near-field Radiation Intensity increases exponentially with decreasing distance from the surface Energy Sources Nano-Gap less than wavelength P N Propagating wave High Density Energy Transfer Requirements 1. Smooth surfaces with nano-scale roughness 2. No electrode on the Emitter TPV Cell GaSb, InGaSb, InAsPSb, etc. - + Electricity cell surface, flat surface

7 Current density[a/cm 2 ] Experimental results Emitter 7 p-n junction cell Cell 約 2.5 倍 dark 0μm 1.1μm 1.2μm 1.5μm No change Far-field with V.F. of unity Voltage[V] Increase in current density by a factor of 2.5 Near- and far-fields

8 Spectral control of radiation transfer by pillar array structure 8 SEM image of W pillars Spectral control was achieved by the height of pillar. Radiation transfer was increased by pillar structure by a factor of 10. 8

9 Spectral control of emission of radiation by microcavities 0.5x0.5x0.5 μm 3 Maximum of emittance ( μm) 2x2 mm 2 25mm Cutoff wavelength λ c Rectangular microcavities

10 Filament with periodical nanoscaled cavities 10 w=150nm d=500nm Ni plane surface 800 h=7 m m a=350nm 2mm 2mm 1 mm

11 Integration between SOFC and biomass gasification 燃料極過電圧 [V] Cathode Air H 2 O O 2- H 2 O 2- H 2 H 2 Steam CO 2, H 2 O Electrolyte Steam reforming reactor with H2 separation film Woody biomass powder + H 2 O Ni/GDC H O 2- ad Electrolyte Ni/GDC+10%BCY 電流密度 [A/cm 2 ] Membrane reactor with H 2 separation film SOFC with an anode including proton conductor H Adsorbed 2 Hydrogen H e - H 2 ad H BCY H Separation film 2 made of silica Ni ad e - Porous aluminum Over-potential for reaction deceases drastically Ni GDC H ad BCY H ad e - O 2- H 2 O, CO 2 Ni catalyst H 2 Increase in area of TPB H 2,CO, H 2 O, C n H m, CO 2 Cellulose with steam

12 Maximum Power Density [W/cm 2 ] Power density of Ni/GDC-BCY anode Terminal Voltage [V] Power Density [W/cm 2 ] Single cell Ni GDC BCY I-V curve and power density Ni/GDC-BCY(20%) 2 15% Ni/GDC-BCY(15%) Ni/GDC-BCY(10%) Ni/GDC-BCY(5%) % 5% 10% Current Density [A/cm 2 ] GDC network is not enough (30%) % 10% 15% 20% BCY ratio Power density increases with amount of BCY if GDC network is enough 1

13 Diesel Particulate Filter (DPF) SiC membrane layer SiC porous supporter (wall-flow DPF) Nano-particle membrane filter (DPMF) Diesel Engine Diesel Particulate Filter (DPF) 1970 Particulate Matter (PM) Cross section of filter

14 DPMF with single Nano-size Pt Particles in silicon oxicarbide DPF Wall membrane membrane DPF Wall 200 µm 10 µm 2.4 µm fine surface pore Single nano-scaled Pt particle emerged in silicon oxicarbide

15 Microscopic Visualization Setup Polish Lens for an All-In-Focus Quartz Glass Lens for microscope 0.5mm long-focusing-lens microscope Adjustor dial for correction Put a glass on Wall 8mm 8mm 15mm Small-sized DPF Quartz glass Insulator Visualization window Small-sized DPF Exhaust gas or High temperature working-gas

16 Microscopic Visualization Setup Setup for microscopic visualization of diesel particulate trapping and oxidation inside the DPF wall. Exhaust gas Glass suction pipe Working gas (O 2 7%, N 2 93%) Regeneration Trapping process