The evaluation of GOES black paint materials

1992 ◽  
Author(s):  
PHILIP CHEN ◽  
LONNY KAUDER ◽  
JACK TRIOLO
Keyword(s):  
2021 ◽  
pp. 128303
Author(s):  
Hussain H. Al-Kayiem ◽  
Ali A. Ismaeel ◽  
Aklilu T. Baheta ◽  
Mohammed A. Aurybi

Author(s):  
Jesus D. Ortega ◽  
Julius E. Yellowhair ◽  
Clifford K. Ho ◽  
Joshua M. Christian ◽  
Charles E. Andraka

Direct solar power receivers consist of tubular arrays, or panels, which are typically tubes arranged side by side and connected to an inlet and outlet manifold. The tubes absorb the heat incident on the surface and transfer it to the fluid contained inside them. To increase the solar absorptance, high temperature black paint or a solar selective coating is applied to the surface of the tubes. However, current solar selective coatings degrade over the lifetime of the receiver and must be reapplied, which reduces the receiver thermal efficiency and increases the maintenance costs. This work presents an evaluation of several novel receiver shapes which have been denominated as fractal like geometries (FLGs). The FLGs are geometries that create a light-trapping effect, thus, increasing the effective solar absorptance and potentially increasing the thermal efficiency of the receiver. Five FLG prototypes were fabricated out of Inconel 718 and tested in Sandia’s solar furnace at two irradiance levels of ∼15 and 30 W/cm2 and two fluid flow rates. Photographic methods were used to capture the irradiance distribution on the receiver surfaces and compared to results from ray-tracing models. This methods provided the irradiance distribution and the thermal input on the FLGs. Air at nearly atmospheric pressure was used as heat transfer fluid. The air inlet and outlet temperatures were recorded, using a data acquisition system, until steady state was achieved. Computational fluid dynamics (CFD) models, using the Discrete Ordinates (DO) radiation and the k-ω Shear Stress Transport (SST) equations, were developed and calibrated, using the test data, to predict the performance of the five FLGs at different air flow rates and irradiance levels. The results showed that relative to a flat plate (base case), the new FLGs exhibited an increase in the effective solar absorptance from 0.86 to 0.92 for an intrinsic material absorptance of 0.86. Peak surface temperatures of ∼1000°C and maximum air temperature increases of ∼200°C were observed. Compared to the base case, the new FLGs showed a clear air outlet temperature increase. Thermal efficiency increases of ∼15%, with respect to the base case, were observed. Several tests, in different days, were performed to assess the repeatability of the results. The results obtained, so far, are very encouraging and display a very strong potential for incorporation in future solar power receivers.


Author(s):  
Rajendra Prasad Arani ◽  
Ravishankar Sathyamurthy ◽  
Ali Chamkha ◽  
Abd Elnaby Kabeel ◽  
Mageshbabu Deverajan ◽  
...  

2017 ◽  
Vol 58 (3) ◽  
pp. 275-299 ◽  
Author(s):  
Kellen Hoxworth

Six African students enact a somber, silent dance. They stage a series of striking images at the base of South African artist Willie Bester's sculptureSara Baartman, in the Chancellor Oppenheimer Library at the University of Cape Town (UCT). Their faces and bodies smeared with black paint, the students articulate their protest ofSara Baartmanin explicitly racial terms, aligning their critiques of economic, colonial, and racial oppression under the sign of blackness.


2000 ◽  
Author(s):  
Doug M. McCroskey ◽  
George C. Abell ◽  
Mike H. Chidester

2019 ◽  
Vol 213 ◽  
pp. 185-191 ◽  
Author(s):  
A.E. Kabeel ◽  
Ravishankar Sathyamurthy ◽  
Swellam W. Sharshir ◽  
A. Muthumanokar ◽  
Hitesh Panchal ◽  
...  

Author(s):  
Onkar Joshi

Water is essential to life. The origin and continuation of mankind is based on water. The supply of drinking water is an important problem for the developing countries. The wooden box has a thickness of 8mm. It consists of a top cover of transparent glass with a tilt of 18°, 26° and is coated with black paint to absorb the maximum possible solar energy. The yield of the single basin solar still is very less and it increases considerably when the solar still was built with copper sheet. An analysis of single slope solar still has done on different tilt angle to optimizing study of tilt angle. They greatly improve the rate of evaporation and the rate of condensation on the cooler surface. The efficiency is higher for solar still made up of copper sheet and its output we have got 1.24 for 18° angle. The optimized tilt angle gave more efficiency than other tilt angle. The optimize water depth is 18mm for 18° angle. This cost-effective design is expected to provide the rural communities an efficient way to convert the brackish water in to potable water.


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