Influence of High Temperature Exposure on the Thermal and Optical Properties of Thermal Oil-Based Solar Nanofluids

2018 ◽  
Vol 7 (6) ◽  
pp. 1045-1052 ◽  
Author(s):  
A. Gimeno-Furio ◽  
N. Navarrete ◽  
R. Martinez-Cuenca ◽  
J. E. Julia ◽  
L. Hernandez
Keyword(s):  
Optical Properties ◽  
High Temperature ◽  
High Temperature Exposure ◽  
Temperature Exposure ◽  
Thermal Oil

Optical Properties of Select Particulates After High-Temperature Exposure

2014 ◽  
Author(s):  
Jonathan Roop ◽  
Sheldon Jeter ◽  
Said I. Abdel-Khalik ◽  
Clifford K. Ho
Keyword(s):  
Optical Properties ◽  
High Temperature ◽  
High Temperatures ◽  
Viable Option ◽  
Solar Absorptance ◽  
High Temperature Exposure ◽  
Central Receiver ◽  
Total Hemispherical Emittance ◽  
Receiver System ◽  
Temperature Exposure

One increasingly viable option for high temperature concentrator solar power (CSP) is a central receiver system with a particle heating receiver (PHR). A PHR system uses suitable particulates to capture and store energy. It is expected that the particles will be sustained at high temperatures (in the range of 300°C or 400°C to 700°C or 800°C or even 1000°C) on most typical days of plant operation, so there is interest in how the particle optical properties might change after prolonged high-temperature exposure. This paper presents the results from experiments conducted over a 5-month period in which samples of various types of particulates including silica sands and alumina proppants were exposed to high temperatures for extended periods of time. The reflectance of a bed of particles was measured at room temperature in 8 wavelength bands using the 410-Solar reflectometer device developed by Surface Optics Corporation. The infrared emittance was determined using the ETS-100 emissometer instrument, also developed by Surface Optics Corporation [1,2]. Particles were heated to 950°C and 350°C, and measurements were recorded at intervals during the exposure so that trends in the optical properties over time could be observed. From the measured data, the total solar absorptance and total hemispherical emittance at high temperature were computed; these results are also presented.

Creep Properties and Interfacial Microstructure of SiC Whisker Reinforced Si3N4

1989 ◽  
Vol 170 ◽  
Author(s):  
Håkan A. Swan ◽  
Colette O'meara
Keyword(s):  
High Temperature ◽  
Creep Resistance ◽  
Interfacial Microstructure ◽  
Deformation Mechanisms ◽  
Amorphous Films ◽  
Creep Tests ◽  
Creep Properties ◽  
High Temperature Exposure ◽  
Temperature Exposure

AbstractPreliminary creep tests were performed on SiC whisker reinforced and matrix Si3N4 material fabricated by the NPS technique. The material was extensively crystallised in the as received material, leaving only thin amorphous films surrounding the grains. No improvement in the creep resistance could be detected for the whisker reinforced material. The deformation mechanisms were found to be that of cavitation in the form of microcracks, predominantly at the whisker/matrix interfaces, and the formation of larger cracks. Extensive oxidation of the samples, as a result of high temperature exposure to air, was observed for the materials tested at 1375°C.

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