Design, manufacturing and testing of an aperture mechanism for a solar reactor

This study presents the test results of our variable aperture mechanism which allows a solar reactor to dynamically respond to the changes in incoming solar radiation. Virtual prototyping was used to check the control system implemented, while experimental testing helped us to identify the drawbacks of the mechanism and the loop holes in the control system. A comparison of variable aperture verses fixed aperture is given to show the benefits of this mechanism. Numerical methods such as Euler and the trapezoidal rule were used in modeling. Tests results show that varying aperture size saves 2.2% energy during a cloudy day and 0.3% on a sunny day. The results from these experiments have also shown that there is a slight deviation of the aperture blades from their required position (by ±0.5 mm to ±1 mm). But overall, the combination of the control system and the selected hardware along with the aperture assembly responded to the changes successfully. The results of our experimental findings and theoretical calculations showed that this variable aperture concept is able to provide more stable internal temperature inside a solar reactor compared to fixed aperture concepts.© 2011 ASME

[1]  A. Steinfeld,et al.  Radiative transfer in a solar chemical reactor for the co-production of hydrogen and carbon by thermal decomposition of methane , 2004 .

[2]  Gilles Flamant,et al.  Experimental study and modeling of a high-temperature solar chemical reactor for hydrogen production from methane cracking , 2007 .

[3]  C. Maffezzoni,et al.  Dynamic analysis and control of a solar power plant—I Dynamic analysis and operation criteria , 1982 .

[4]  Akiba Segal,et al.  Optimized working temperatures of a solar central receiver , 2003 .

[5]  G. Flamant,et al.  Solar hydrogen production from the thermal splitting of methane in a high temperature solar chemical reactor , 2006 .

[6]  A. Steinfeld,et al.  Unsteady radiative heat transfer within a suspension of ZnO particles undergoing thermal dissociation , 2006 .

[7]  Aldo Steinfeld,et al.  Hydrogen production by hydrogen sulfide splitting using concentrated solar energy – Thermodynamics and economic evaluation , 2010 .

[8]  Jörg Petrasch,et al.  Dynamics and control of solar thermochemical reactors , 2009 .

[9]  Nesrin Ozalp,et al.  Solar decomposition of fossil fuels as an option for sustainability , 2009 .

[10]  Nesrin Ozalp,et al.  Effect of Cameralike Aperture in Quest for Maintaining Quasi-Constant Radiation Inside a Solar Reactor , 2011 .

[11]  M. Israeli,et al.  Production of hydrogen and carbon by solar thermal methane splitting. IV. Preliminary simulation of a confined tornado flow configuration by computational fluid dynamics , 2007 .

[12]  Aldo Steinfeld,et al.  The solar thermal decarbonization of natural gas , 2001 .

[13]  G. Flamant,et al.  Solar thermal reduction of ZnO and SnO2: Characterization of the recombination reaction with O2 , 2010 .

[14]  Aldo Steinfeld,et al.  Kinetic investigation of the thermal decomposition of CH4 by direct irradiation of a vortex-flow laden with carbon particles , 2004 .

[15]  Aldo Steinfeld,et al.  Optimum aperture size and operating temperature of a solar cavity-receiver , 1993 .

[16]  R. A. Hill.  Variable aperture neutron collimator — II , 1984 .