1. School of Energy Science and Engineering, Harbin Institute of Technology, Harbin 15001, China 2. College of Metallurgy and Energy, North China University of Science and Technology, Tangshan 063009, China
This paper investigated radiation heat transfer and temperature distributions of solar thermochemical reactor for syngas production using the finite volume discrete ordinate method (fvDOM) and P1 approximation for radiation heat transfer. Different parameters including absorptivity, emissivity, reflection based radiation scattering, and carrier gas flow inlet velocity that would greatly affect the reactor thermal performance were sufficiently investigated. The fvDOM approximation was used to obtain the radiation intensity distribution along the reactor. The drop in the temperature resulted from the radiation scattering was further investigated using the P1 approximation. The results indicated that the reactor temperature difference between the P1 approximation and the fvDOM radiation model was very close under different operating conditions. However, a big temperature difference which increased with an increase in the radiation emissivity due to the thermal non-equilibrium was observed in the radiation inlet region. It was found that the incident radiation flux distribution had a strong impact on the temperature distribution throughout the reactor. This paper revealed that the temperature drop caused by the boundary radiation heat loss should not be neglected for the thermal performance analysis of solar thermochemical reactor.
Radiation inlet: T = Parameter study Carrier gas inlet: T = 300
300
300
U/(m?s–1)
Fixed value Carrier gas inlet: v = Parameter study Radiation inlet: u = Parameter study
Zero gradient
Zero gradient
Prgh/atm
Fixed flux pressure Value: Parameter study
Zero gradient
Fixed flux pressure Value: Parameter study
P/atm
Calculated Value: internal field
Calculated Value= internal field
Calculated Value: internal field
G/(W?m–2)
Marshak radiation T = Parameter study Emissivity= 1.0 Value: 0.0
Marshak radiation T = Parameter study Emissivity= 1.0 Value: 0.0
Marshak radiation T = Parameter study Emissivity= 1.0 Value: 0.0
I/(W?m–2?sr–1)
Grey diffuse radiation
Grey diffuse radiation
Grey diffuse radiation
aeff/(m2?s–1)
Alphat wall function Value: 0.0
Alphat wall function Value: 0.0
Alphat wall function Value: 0.0
meff/(kg?m–1?s–1)
Mutk wall function Value: 0.00
Mutk wall function Value: 0.00
Mutk wall function Value: 0.00
εT/(m2?s–3)
Epsilon wall function Value: 0.01
Epsilon wall function Value: 0.01
Epsilon wall function Value: 0.01
K/(m2?s–2)
kqR wall function Value: 0.1
kqR wall function Value: 0.1
kqR wall function Value: 0.1
Tab.1
Fig.2
Fig.3
Fig.4
Fig.5
Fig.6
Fig.7
Fig.8
Fig.9
C
Linear anisotropic phase function coefficient
cP
Specific heat capacity at constant pressure, J/(kg?K)
DP
Pressure diffusivity
G
Incident radiation flux, W/m2
Gw
incident radiation flux at the wall, W/m2
g
Gravitational acceleration, m/s2
h
Specific enthalpy, J/kg
Ib,r
Blackbody radiation intensity, W/(m2?mm?sr)
Ir,s
Radiation intensity, W/(m2?sr)
K
Kinetic energy, m2/s2
k
Thermal conductivity, W/(m?K)
Unit normal vector to the wall
P
Total pressure, atm
Pr
Prandtl number
Reference pressure, atm
Prgh
Dynamic pressure, atm
qr
Radiative flux vector, W/m2
r
Point
s
Direction
Sf
Patch face area vectors
T
Temperature, K
Tw
Wall temperature, K
u
Velocity, m/s
Greek letters
α
Absorptivity
αeff
Effective thermal diffusivity, m2/s
εT
Thermal dissipation rate, m2/s3
ε
Emission coefficient
εw
Wall emissivity
ϕ
Flux
Predicted flux field
Absorption coefficient, m-1
μeff
Molecular viscosity, kg/m?s
μ
Dynamic viscosity, kg/m?s
Scattering phase function
ρ
Density, kg/m3
σ
Stefan-Boltzmann constant, W/(m2?K4)
σs
Scattering coefficient
1
Shuai Y, Wang F Q, Xia X L, Tan H P, Liang Y C. Radiative properties of a solar cavity receiver/reactor with quartz window. International Journal of Hydrogen Energy, 2011, 36(19): 12148–12158 https://doi.org/10.1016/j.ijhydene.2011.07.013
2
Suter S, Steinfeld A, Haussener S . Pore-level engineering of macroporous media for increased performance of solar-driven thermochemical fuel processing. International Journal of Heat and Mass Transfer, 2014, 78: 688–698 https://doi.org/10.1016/j.ijheatmasstransfer.2014.07.020
3
Palumbo R, Keunecke M, Möller S , Steinfeld A . Reflections on the design of solar thermal chemical reactors: thoughts in transformation. Energy, 2004, 29(5–6): 727–744 https://doi.org/10.1016/S0360-5442(03)00180-4
4
Rupesh S, Muraleedharan C, Arun P . Energy and exergy analysis of syngas production from different biomasses through air-steam gasification. Frontiers in Energy, 2016, [Epub ahead of print]
5
Ni W, Chen Z. Synergistic utilization of coal and other energy—key to low carbon economy. Frontiers in Energy, 2011, 5(1): 1–19 https://doi.org/10.1007/s11708-010-0136-4
6
Müller R, Haeberling P, Palumbo R D . Further advances toward the development of a direct heating solar thermal chemical reactor for the thermal dissociation of ZnO(s). Solar Energy, 2006, 80(5): 500–511 https://doi.org/10.1016/j.solener.2005.04.015
7
Bellan S, Alonso E, Gomez-Garcia F , Perez-Rabago C , Gonzalez-Aguilar J , Romero M . Thermal performance of lab-scale solar reactor designed for kinetics analysis at high radiation fluxes. Chemical Engineering Science, 2013, 101: 81–89 https://doi.org/10.1016/j.ces.2013.06.033
8
Levêqque G, Abanades S. Investigation of thermal and carbothermal reduction of volatile oxides (ZnO, SnO2, GeO2, and MgO) via solar-driven vacuum thermogravimetry for thermochemical production of solar fuels. Thermochimica Acta, 2015, 605: 86–94 https://doi.org/10.1016/j.tca.2015.02.015
9
Alonso E, Romero M. A directly irradiated solar reactor for kinetic analysis of non-volatile metal oxides reductions. International Journal of Energy Research, 2015, 39(9): 1217–1228 https://doi.org/10.1002/er.3320
10
Ackermann S, Takacs M, Scheffe J , Steinfeld A . Reticulated porous ceria undergoing thermochemical reduction with high-flux irradiation. International Journal of Heat and Mass Transfer, 2017, 107: 439–449 https://doi.org/10.1016/j.ijheatmasstransfer.2016.11.032
11
Bachirou G L, Shuai Y, Zhang J , Huang X , Yuan Y, Tan H P. Syngas production by simultaneous splitting of H2O and CO2 via iron oxide (Fe3O4) redox reactions under high-pressure. International Journal of Hydrogen Energy, 2016, 41(44): 19936–19946 https://doi.org/10.1016/j.ijhydene.2016.09.053
12
Kodama T, Gokon N. Thermochemical cycles for high-temperature solar hydrogen production. Chemical Reviews, 2007, 107(10): 4048–4077 https://doi.org/10.1021/cr050188a
13
Steinfeld A, Schubnell M. Optimum aperture size and operating temperature of a solar cavity-receiver. Solar Energy, 1993, 50(1): 19–25 https://doi.org/10.1016/0038-092X(93)90004-8
14
Costandy J, El Ghazal N, Mohamed M T , Menon A , Shilapuram V , Ozalp N . Effect of reactor geometry on the temperature distribution of hydrogen producing solar reactors. International Journal of Hydrogen Energy, 2012, 37(21): 16581–16590 https://doi.org/10.1016/j.ijhydene.2012.02.193
15
Kodama T. High-temperature solar chemistry for converting solar heat to chemical fuels. Progress in Energy and Combustion Science, 2003, 29(6): 567–597 https://doi.org/10.1016/S0360-1285(03)00059-5
16
Guene Lougou B , Hong J, Shuai Y, Huang X , Yuan Y, Tan H P. Production mechanism analysis of H2 and CO via solar thermochemical cycles based on iron oxide (Fe3O4) at high temperature. Solar Energy, 2017, 148: 117–127 https://doi.org/10.1016/j.solener.2017.03.050
17
Loutzenhiser P G , Galvez M E , Hischier L , Stamatiou A , Frei A, Steinfeld A. CO2 splitting via two-step solar thermochemical cycles with Zn/ZnO and FeO/Fe3O4 redox reactions II: kinetic analysis. Energy & Fuels, 2009, 23(5): 2832–2839 https://doi.org/10.1021/ef801142b
18
Gokon N, Mataga T, Kondo N , Kodama T . Thermochemical two-step water splitting by internally circulating fluidized bed of NiFe2O4 particles: successive reaction of thermal-reduction and water-decomposition steps. International Journal of Hydrogen Energy, 2011, 36(8): 4757–4767 https://doi.org/10.1016/j.ijhydene.2011.01.076
19
Romero M, Steinfeld A. Concentrating solar thermal power and thermochemical fuels. Energy & Environmental Science, 2012, 5(11): 9234–9245 https://doi.org/10.1039/c2ee21275g
20
Alonso E, Pérez-Rábago C, González-Aguilar J, Romero M . A novel lab-scale solar reactor for kinetic analysis of nonvolatile metal oxides thermal reductions. Energy Procedia, 2014, 57: 561–569 https://doi.org/10.1016/j.egypro.2014.10.210
21
Abanades S, Charvin P, Flamant G . Design and simulation of a solar chemical reactor for the thermal reduction of metal oxides: case study of zinc oxide dissociation. Chemical Engineering Science, 2007, 62(22): 6323–6333 https://doi.org/10.1016/j.ces.2007.07.042
22
Schunk L O, Haeberling P, Wepf S , Wuillemin D , Meier A , Steinfeld A . A receiver-reactor for the solar thermal dissociation of zinc oxide. Journal of Solar Energy Engineering, Transactions of the ASME, 2008, 130(2): 0210091–0210096
23
Wang M, Siddiqui K. The impact of geometrical parameters on the thermal performance of a solar receiver of dish-type concentrated solar energy system. Renewable Energy, 2010, 35(11): 2501–2513 https://doi.org/10.1016/j.renene.2010.03.021
24
Chabane F, Hatraf N, Moummi N . Experimental study of heat transfer coefficient with rectangular baffle fin of solar air heater. Frontiers in Energy, 2014, 8(2): 160–172 https://doi.org/10.1007/s11708-014-0321-y
25
Steinfeld A, Schubnell M. Optimum aperture size and operating temperature of a solar cavity-receiver. Solar Energy, 1993, 50(1): 19–25 https://doi.org/10.1016/0038-092X(93)90004-8
Cheng Z D, He Y L, Xiao J, Tao Y B , Xu R J . Three-dimensional numerical study of heat transfer characteristics in the receiver tube of parabolic trough solar collector. International Communications in Heat and Mass Transfer, 2010, 37(7): 782–787 https://doi.org/10.1016/j.icheatmasstransfer.2010.05.002
28
Mao Q, Shuai Y, Yuan Y . Study on radiation flux of the receiver with a parabolic solar concentrator system. Energy Conversion and Management, 2014, 84: 1–6 https://doi.org/10.1016/j.enconman.2014.03.083
29
Villafán-Vidales H I , Abanades S , Caliot C , Romero-Paredes H . Heat transfer simulation in a thermochemical solar reactor based on a volumetric porous receiver. Applied Thermal Engineering, 2011, 31(16): 3377–3386 https://doi.org/10.1016/j.applthermaleng.2011.06.022
30
Wu Z Y, Caliot C, Flamant G , Wang Z. Coupled radiation and flow modeling in ceramic foam volumetric solar air receivers. Solar Energy, 2011, 85(9): 2374–2385 https://doi.org/10.1016/j.solener.2011.06.030
31
Yin J Y, Liu L H. Analysis of the radiation heat transfer process of phase change for a liquid droplet radiator in space power systems. Frontiers in Energy, 2011, 5(2): 166–173 https://doi.org/10.1007/s11708-010-0105-y
32
Guene Lougou B , Shuai Y , Xing H, Yuan Y, Tan H P . Thermal performance analysis of solar thermochemical reactor for syngas production. International Journal of Heat and Mass Transfer, 2017, 111: 410–418 https://doi.org/10.1016/j.ijheatmasstransfer.2017.04.007
33
Wang F Q, Shuai Y, Tan H P , Yu C L . Thermal performance analysis of porous media receiver with concentrated solar irradiation. International Journal of Heat and Mass Transfer, 2013, 62(1): 247–254 https://doi.org/10.1016/j.ijheatmasstransfer.2013.03.003
34
Wang F Q, Shuai Y, Tan H P , Zhang X F , Mao Q J . Heat transfer analyses of porous media receiver with multi-dish collector by coupling MCRT and FVM method. Solar Energy, 2013, 93: 158–168 https://doi.org/10.1016/j.solener.2013.04.004
35
Wang F Q, Tan J Y, Yong S, Tan H P , Chu S X . Thermal performance analyses of porous media solar receiver with different irradiative transfer models. International Journal of Heat and Mass Transfer, 2014, 78: 7–16 https://doi.org/10.1016/j.ijheatmasstransfer.2014.06.035
36
Trépanier J-Y , Melot M , Camarero R , Petro E . Comparison of two models for radiative heat transfer in high-temperature thermal plasmas. Modelling and Simulation in Engineering, 2011, 285108
37
Kräupl S, Steinfeld A. Experimental investigation of a vortex-flow solar chemical reactor for the combined ZnO-reduction and CH4-reforming. Journal of Solar Energy Engineering, Transactions of the ASME, 2001, 123(3): 237–243
38
Modest M F. Radiative Heat Transfer. 3rd edition. San Diego: Academic Press, 2013
39
Modest M F. Radiative Heat Transfer. Burlington: Academic Press, 2003
40
Sazhin S S, Sazhina E M, Faltsi-Saravelou O, Wild P . The P-1 model for thermal radiation transfer: advantages and limitations. Fuel, 1996, 75(3): 289–294 https://doi.org/10.1016/0016-2361(95)00269-3
41
Abanades S, Flamant G. Experimental study and modeling of a high temperature solar chemical reactor for hydrogen production from methane cracking. International Journal of Hydrogen Energy, 2007, 32(10–11): 1508–1515 https://doi.org/10.1016/j.ijhydene.2006.10.038
42
Abanades S, Flamant G. Production of hydrogen by thermal methane splitting in a nozzle-type laboratory scale solar reactor. International Journal of Hydrogen Energy, 2005, 30(8): 843–853 https://doi.org/10.1016/j.ijhydene.2004.09.006
