Characterization of Pyromark 2500 Paint for High-Temperature Solar Receivers

2013 ◽  
Vol 136 (1) ◽  
Author(s):  
Clifford K. Ho ◽  
A. Roderick Mahoney ◽  
Andrea Ambrosini ◽  
Marlene Bencomo ◽  
Aaron Hall ◽  
...  
Keyword(s):  
Crystal Structure ◽  
High Temperature ◽  
Elevated Temperatures ◽  
Normal Incidence ◽  
Radiative Properties ◽  
Solar Absorptance ◽  
Thermal Emittance ◽  
Percentage Points ◽  
Original Coating

Pyromark 2500 is a silicone-based high-temperature paint that has been used on central receivers to increase solar absorptance. The radiative properties, aging, and selective absorber efficiency of Pyromark 2500 are presented in this paper for use as a baseline for comparison to high-temperature solar selective absorber coatings currently being developed. The solar absorptance ranged from ∼0.97 at near-normal incidence angles to ∼0.8 at glancing (80°) incidence angles, and the thermal emittance ranged from ∼0.8 at 100 °C to ∼0.9 at 1000 °C. After thermal aging at temperatures of ∼750 °C or higher, the solar absorptance decreased by several percentage points within a few days. It was postulated that the substrate may have contributed to a change in the crystal structure of the original coating at elevated temperatures.

Characterization of Pyromark 2500 for High-Temperature Solar Receivers

2012 ◽  
Author(s):  
Clifford K. Ho ◽  
A. Roderick Mahoney ◽  
Andrea Ambrosini ◽  
Marlene Bencomo ◽  
Aaron Hall ◽  
...  
Keyword(s):  
High Temperature ◽  
Elevated Temperatures ◽  
Normal Incidence ◽  
Radiative Properties ◽  
Plant Laboratory ◽  
Solar Absorptance ◽  
Total Hemispherical Emittance ◽  
Curing Methods ◽  
The Cost ◽  
Solar Receiver

Pyromark 2500 is a silicone-based high-temperature paint that has been used on central receivers to increase solar absorptance. The cost, application, curing methods, radiative properties, and absorber efficiency of Pyromark 2500 are presented in this paper for use as a baseline for comparison to high-temperature solar selective absorber coatings currently being developed. The directional solar absorptance was calculated from directional spectral absorptance data, and values for pristine samples of Pyromark 2500 were as high as 0.96–0.97 at near normal incidence angles. At higher irradiance angles (>40°–60°), the solar absorptance decreased. The total hemispherical emittance of Pyromark 2500 was calculated from spectral directional emittance data measured at room temperature and 600°C. The total hemispherical emittance values ranged from ∼0.80–0.89 at surface temperatures ranging from 100°C – 1,000°C. The aging and degradation of Pyromark 2500 with exposure at elevated temperatures were also examined. Previous tests showed that solar receiver panels had to be repainted after three years due to a decrease in solar absorptance to 0.88 at the Solar One central receiver pilot plant. Laboratory studies also showed that exposure of Pyromark 2500 at high temperatures (750°C and higher) resulted in significant decreases in solar absorptance within a few days. However, at 650°C and below, the solar absorptance did not decrease appreciably after several thousand hours of testing. Finally, the absorber efficiency of Pyromark 2500 was determined as a function of temperature and irradiance using the calculated solar absorptance and emittance values presented in this paper.

High Thermal Stability of Mo/Si3N4/Mo/Si3N4/SiO2 Multilayer Solar Selective Coatings

2015 ◽  
Vol 1102 ◽  
pp. 67-71 ◽  
Author(s):  
Rui Hua Yang ◽  
Jin Yang Liu ◽  
Li Mei Lin ◽  
Fa Chun Lai ◽  
Yan Qu ◽  
...  
Keyword(s):  
Thermal Stability ◽  
High Temperature ◽  
Multilayer Structure ◽  
High Thermal Stability ◽  
Solar Absorptance ◽  
Selective Coating ◽  
Thermal Emittance ◽  
Quartz Substrates ◽  
Thermal Stability Of

In terms of good optical properties and high thermal stability, Mo/Si3N4/Mo/Si3N4/SiO2 coatings based on metal/dielectric multilayer structure were adapted to the solar selective coating at high operating temperatures. The coatings exhibited high solar absorptance in the range of 0.924 ~ 0.936 and low thermal emittance of 0.114 ~ 0.118. The coatings deposited on quartz substrates were thermally stable up to 625 °C in air for 2 h, while they were degraded at 650 °C from the characterization of the absorptance and emittance. The degradation of the coatings was mainly due to the oxidation of molybdenum in air, which was confirmed by Raman spectroscopy. Compared with the thermal stability in air, the coatings were much more stable in vacuum under high temperature. The remarkable thermal stability of the Mo/Si3N4/Mo/Si3N4/SiO2 coatings in air and in vacuum makes them suitable to be applied at high temperature applications.

Performance and Reliability of MEMS Gyroscopes and Packaging at High Temperatures

2010 ◽  
Vol 2010 (HITEC) ◽  
pp. 000359-000366 ◽  
Author(s):  
Patrick McCluskey ◽  
Chandradip Patel ◽  
David Lemus
Keyword(s):  
High Temperature ◽  
Indoor Environment ◽  
Elevated Temperatures ◽  
High Sensitivity ◽  
Effect Of Temperature ◽  
Gps Tracking ◽  
Mems Gyroscope ◽  
Mems Gyroscopes ◽  
Gyroscope Sensor

Elevated temperatures can significantly affect the performance and reliability of MEMS gyroscope sensors. A MEMS vibrating resonant gyroscope measures angular velocity via a displacement measurement which can be on the order on nanometers. High sensitivity to small changes in displacement causes the MEMS Gyroscope sensor to be strongly affected by changes in temperature which can affect the displacement of the sensor due to thermal expansion and thermomechanical stresses. Analyzing the effect of temperature on MEMS gyroscope sensor measurements is essential in mission critical high temperature applications, such as inertial tracking of the movement of a fire fighter in a smoke filled indoor environment where GPS tracking is not possible. In this paper, we will discuss the development of the high temperature package for the tracking application, including the characterization of the temperature effects on the performance of a MEMS gyroscope. Both stationary and rotary tests were performed at room and at elevated temperatures on 10 individual single axis MEMS gyroscope sensors.

Mn-Mg disordering in cummingtonite: a high-temperature neutron powder diffraction study

2000 ◽  
Vol 64 (2) ◽  
pp. 255-266 ◽  
Author(s):  
J. J. Reece ◽  
S. A. T. Redfern ◽  
M. D. Welch ◽  
C. M. B. Henderson
Keyword(s):  
Crystal Structure ◽  
Phase Transition ◽  
New York ◽  
High Temperature ◽  
Powder Diffraction ◽  
Elevated Temperatures ◽  
Neutron Powder Diffraction ◽  
Site Preference ◽  
A Site

AbstractThe crystal structure of a manganoan cummingtonite, composition [M4](Na0.13Ca0.41Mg0.46Mn1.00) [M1,2,3](Mg4.87Mn0.13)(Si8O22)(OH)2, (Z = 2), a = 9.5539(2) Å, b = 18.0293(3) Å, c = 5.2999(1) Å, β = 102.614(2)° from Talcville, New York, has been refined at high temperature using in situ neutron powder diffraction. The P21/m to C2/m phase transition, observed as spontaneous strains +ε1 = −ε2, occurs at ˜107°C. Long-range disordering between Mg2+ and Mn2+ on the M(4) and M(2) sites occurs above 550°C. Mn2+ occupies the M(4) and M(2) sites preferring M(4) with a site-preference energy of 24.6±1.5 kJ mol−1. Disordering induces an increase in XMnM2 and decrease in XMnM4 at elevated temperatures. Upon cooling, the ordered states of cation occupancy are ‘frozen in’ and strains in lattice parameters are maintained, suggesting that re-equilibration during cooling has not taken place.

Structural properties and presence of protons in Ba0.9Gd0.1Zr1−x−ySnxInyO3−(y−0.1)∕2 perovskites

2016 ◽  
Vol 09 (04) ◽  
pp. 1641005 ◽  
Author(s):  
Wojciech Skubida ◽  
Konrad Świerczek
Keyword(s):  
Crystal Structure ◽  
High Temperature ◽  
Solid Electrolytes ◽  
Dominant Role ◽  
Spectroscopy Analysis ◽  
High Temperature Xrd ◽  
Thermogravimetric Studies ◽  
Perovskite Type ◽  
Mass Spectroscopy Analysis

In this work, structural characterization of selected perovskite-type compounds from Ba[Formula: see text]Gd[Formula: see text]Zr[Formula: see text]SnxInyO[Formula: see text] group is given, including high temperature XRD measurements. An evidence of water incorporation into the crystal structure of the materials in a form of OH[Formula: see text] is discussed on a basis of thermogravimetric studies, with mass spectroscopy analysis of the gases released from samples on heating/cooling. As expected, oxygen non-stoichiometry was found to play a dominant role concerning possibility of water uptake. In addition, a rather strong affinity of the materials towards CO2 was documented, which seems to be a problem concerning possible application of the compounds as proton conducting solid electrolytes.

Ni6B22O39·H2O – extending the field of nickel borates

2017 ◽  
Vol 72 (12) ◽  
pp. 967-975 ◽  
Author(s):  
Martin K. Schmitt ◽  
Hubert Huppertz
Keyword(s):  
Crystal Structure ◽  
High Pressure ◽  
High Temperature ◽  
Temperature Reaction ◽  
Orthorhombic Space Group ◽  
X Ray ◽  
High Temperature Reaction ◽  
High Pressure High Temperature ◽  
Related Phase

AbstractNi6B22O39·H2O was synthesized in a high-pressure/high-temperature reaction at 5 GPa/900°C. It crystallizes in the orthorhombic space group Pmn21 (no. 31) with the lattice parameters a=7.664(2), b=8.121(2) and c=17.402(2) Å. The crystal structure is discussed with regard to the isotypic compounds M6B22O39·H2O (M=Fe, Co) and the structurally related phase Cd6B22O39·H2O. Furthermore, the characterization of Ni6B22O39·H2O via X-ray powder diffraction and vibrational spectroscopy is reported.

scholarly journals Improved High Temperature Solar Absorbers for Use in Concentrating Solar Power Central Receiver Applications

2011 ◽  
Author(s):  
Andrea Ambrosini ◽  
Timothy N. Lambert ◽  
Marlene Bencomo ◽  
Aaron Hall ◽  
Kent vanEvery ◽  
...  
Keyword(s):  
High Temperature ◽  
Solar Power ◽  
Low Cost ◽  
Concentrating Solar Power ◽  
Solar Absorptance ◽  
Thermal Emittance ◽  
Solar Absorbers ◽  
Operating Temperatures ◽  
Stability Issues ◽  
The Cost

Concentrating solar power (CSP) systems use solar absorbers to convert the heat from sunlight to electric power. Increased operating temperatures are necessary to lower the cost of solar-generated electricity by improving efficiencies and reducing thermal energy storage costs. Durable new materials are needed to cope with operating temperatures < 600°C. The current coating technology (Pyromark High Temperature paint) has a solar absorptance in excess of 0.95 but a thermal emittance greater than 0.8, which results in large thermal losses at high temperatures. In addition, because solar receivers operate in air, these coatings have long term stability issues that add to the operating costs of CSP facilities. Ideal absorbers must have high solar absorptance (>0.95) and low thermal emittance (<0.3 at receiver surface operating temperatures), be stable in air, and be low-cost and readily manufacturable. Recent efforts at Sandia National Laboratories have begun to address the issue of more efficient solar selective coatings for tower applications. This paper will present an overview of these efforts which address the development of new coatings on several fronts.

Synthesis and structural characterization of Li3Y(BO3)2

2017 ◽  
Vol 72 (2) ◽  
pp. 153-158 ◽  
Author(s):  
Sebastian Bräuchle ◽  
Hubert Huppertz
Keyword(s):  
Crystal Structure ◽  
High Temperature ◽  
Solid State ◽  
Boric Acid ◽  
Structural Characterization ◽  
Diffraction Data ◽  
Lithium Carbonate ◽  
X Ray Diffraction ◽  
X Ray

AbstractLi3Y(BO3)2 was prepared by high-temperature solid state synthesis at 900°C in a platinum crucible from lithium carbonate, boric acid, and yttrium(III) oxide. The compound crystallizes monoclinically in the space group P21/c (no. 14) (Z=4) isotypically to Li3Gd(BO3)2. The structure was refined from single-crystal X-ray diffraction data: a=8.616(3), b=6.416(3), c=10.014(2) Å, β=116.6(2)°, V=494.9(3) Å3, R1=0.0211, and wR2=0.0378 for all data. The crystal structure of Li3Y(BO3)2 consists of [Y2O14] dinuclear units, which are interconnected to each other by planar B(1)O3 groups and LiO4 tetrahedra via common edges and corners along the a axis.

Influence of Ni/Cr Substitution for Mn on Crystal Structure and Electrochemical Performance of LiMn2O4 Cathode Materials

2014 ◽  
Vol 912-914 ◽  
pp. 204-209 ◽  
Author(s):  
Fei Luo ◽  
Lin Zhang ◽  
Jian Hua Wang ◽  
Yu Zhong Guo
Keyword(s):  
Crystal Structure ◽  
High Temperature ◽  
Cathode Materials ◽  
Spinel Structure ◽  
Solution Process ◽  
Electrochemical Tests ◽  
Cr Substitution ◽  
Co Precipitation ◽  
Discharge Capacities

LiMn2O4and LiNi0.5-xCr2xMn1.5-xO4(x=0, 0.05) cathode materials of spinel structure were prepared via co-precipitation derived precursors and subsequent high-temperature sintering between the precursors and LiOH. XRD, SEM and electrochemical tests were performed for the characterization of the as-prepared samples. The results show that the substitutions of Ni and Cr for Mn can not prevent Mn2+from being oxidized into Mn3+in solution process, yet do not change their final crystal structures of spinel with or without substitution, and after substitution the first charge and discharge capacities decrease but its cyclic capability is improved significantly, especially for the Ni and Cr co-substitution

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