Solar Blind Pyrometer Temperature Measurements in High Temperature Solar Thermal Reactors: A Method for Correcting the System-Sensor Cavity Reflection Error

We developed a method that enables one to correct solar blind pyrometer cavity temperature measurements for the system-sensor reflection error. The method is valid for measurements made on diffusely emitting and reflecting cavity surfaces when there is no participating medium between the pyrometer and the surface of interest. The surfaces' emissivities must be known. The procedure gives the uncertainty interval associated with the correction. The procedure was validated by measuring surface temperatures in a solar reactor insulated with Yttria-stabilized Zirconia felt receiving concentrated solar radiation. The temperature range of the experimental study was from 1100-1600 K. Temperature measurements made with a pyrometer having a narrow band filter centered at 1.398 μm were compared to temperatures measured with Zirconia felt shielded thermocouples. Uncorrected pyrometer measurements differed from the thermocouple measurements by as much as 350 K. The thermocouple measurements mostly fell within the system-sensor uncertainty interval of the corrected temperature measurements. The uncertainty interval depends both on the number of surfaces probed with the pyrometer and the nature of the solar blind filter. A numerical simulation study showed that a UV filter centered at a wavelength near 0.285 μm gives tighter system-sensor uncertainty intervals than an IR filter centered at 1.398 μm.

[1]  Aldo Steinfeld,et al.  A new high-flux solar furnace for high-temperature thermochemical research , 1999 .

[2]  Anke Weidenkaff,et al.  A solar chemical reactor for co-production of zinc and synthesis gas , 1998 .

[3]  Robert Palumbo,et al.  DESIGN ASPECTS OF SOLAR THERMOCHEMICAL ENGINEERING—A CASE STUDY: TWO-STEP WATER-SPLITTING CYCLE USING THE Fe3O4/FeO REDOX SYSTEM , 1999 .

[4]  Nicola Rohner,et al.  Measurement of High Temperatures in the DLR Solar Furnace by UV-B Detection , 2003 .

[5]  K. J. Ives,et al.  Experimental Methods (2) , 1978 .

[6]  Wolfgang Hoffelner,et al.  Recycling of hazardous solid waste material using high-temperature solar process heat. 2. Reactor design and experimentation. , 2003, Environmental science & technology.

[7]  A theory of reflections for traceable radiation thermometry , 1995 .

[8]  Robert Palumbo,et al.  A two-cavity reactor for solar chemical processes: heat transfer model and application to carbothermic reduction of ZnO , 2004 .

[9]  C. Gueymard,et al.  Analysis and Experimental Results of Solar-Blind Temperature Measurements in Solar Furnaces , 2004 .

[10]  H. R. Tschudi,et al.  Simultaneous measurement of irradiation, temperature and reflectivity on hot irradiated surfaces , 1995 .

[11]  Y. S. Touloukian,et al.  Thermal radiative properties: Nonmetallic solids. , 1972 .

[12]  Entwicklung eines Reaktors zur solarthermischen Herstellung von Zink aus Zinkoxid zur Energiespeicherung mit Hilfe konzentrierter Sonnenstrahlung , 2001 .

[13]  Robert Palumbo,et al.  The production of zinc by thermal dissociation of zinc oxide - Solar chemical reactor design , 1999 .

[14]  Aldo Steinfeld,et al.  Experimental Investigation of a Vortex-Flow Solar Chemical Reactor for the Combined ZnO-Reduction and CH4-Reforming* , 2001 .

[15]  Aldo Steinfeld,et al.  Pulsed Gas Feeding for Stoichiometric Operation of a Gas-Solid Vortex Flow Solar Chemical Reactor , 2001 .

[16]  M. Schubnell,et al.  Measuring temperatures in the presence of external radiation by flash assisted multiwavelength pyrometry , 1999 .

[17]  Chr. Müller,et al.  Temperature measurement under concentrated radiation , 1996 .

[18]  Robert Palumbo,et al.  Reflections on the design of solar thermal chemical reactors: thoughts in transformation , 2004 .

[19]  H. Tschudi,et al.  Pyrometric Temperature Measurements in Solar Furnaces , 2001 .

[20]  The development of a solar chemical reactor for the direct thermal dissociation of zinc oxide , 2001 .

[21]  P. Saunders.  Reflection errors and uncertainties for dual and multiwavelength pyrometers , 2000 .

[22]  Paul C. Ivey,et al.  An overview of the measurement errors associated with gas turbine aeroengine pyrometer systems , 2002 .