Selective Solar Surface Solar Based on Black Chromium: Influence of Electrodeposition Parameters in the Absorption of Surfaces

Abstract

The search for the reduction of costs for the implementation of renewable energies implies in the optimization of the parameters of the manufacturing processes of consolidated technologies. Among these technologies are the solar collectors composed of absorber films characterized by high absorption in the spectrum range corresponding to solar radiation and low emittance in the infrared range, allowing an increase in the collector's operating temperature (300 to 700°C). The present work produced selective surfaces based on black chrome absorber films on stainless steel substrate by electrodeposition. The substrates were immersed in a chromium trioxide bath with hexafluorosilicic acid using a Pb-Sn electrode. In the project some parameters of deposition were evaluated (time, distance and voltage) and their influence on the surface roughness of the coatings obtained by correlating them with the absorptions of the produced surfaces. For this, the surfaces produced were characterized by UV-Vis-NIR, profilometry and SEM. The results indicate that the working distance directly influenced the increase of the films absorption and that the influence of the surface roughness on the film absorption is related to the electrodeposition time as the voltage is raised.

Crescimento de Salicornia ramosissima em resposta a aplicação de diferentes condicionadores e níveis de umidade de um solo salino-sódico

“…A nutrição correta é primordial para a saúde da mãe e do bebê. O diagnóstico de anemia da mãe no período gestacional (diagnosticado nos encontros do pré-natal) e a prematuridade, por exemplo, podem ser fatores de risco para o baixo peso da criança ao nascer (GONÇALVES et. al, 2019).…”

Characterization and application of a selective coating for solar collectors from of the cashew nut shell liquid

“…Therefore, there will be only natural convection between the surface and the glass cover. The loss by natural convection is given by equation (2).…”

“…The depletion of fossil fuel reserves and climate change caused by atmospheric pollution has led the human being to seek alternatives that are less harmful to the environment. 1 Concern and awareness of the population together with the growing world demand for energy, opens space for the study of renewable energies, 2 among them, the best use of solar energy, considered as the most abundant source of energy renewable energy.…”

Deposition of ultra-black nickel phosphorus coatings

“…Galvanic black coatings are used to absorb light in optical devices and collectors, which convert light energy into heat, as well as protective and decorative coatings for various products [1][2][3]. In most cases, black chrome and nickel coatings are used for these purposes [4][5][6][7][8][9][10]. Known disadvantages of chromium plating processes are the difficulty of implementation and high energy intensity, due to the need to heat solutions and losses due to the side reaction of hydrogen evolution.…”