Effect of copper coating on spherical distillers

• DOI: https://doi.org/10.22533/at.ed.8208162614012

• Palavras-chave: Solar distiller, Thermal efficiency, Copper coating.

• Keywords: Solar distiller, Thermal efficiency, Copper coating.

• Abstract:

  This study evaluates the thermal performance and productivity of an improved spherical solar distiller by incorporating a laminated copper coating on the absorber plate, which is also coated with black automotive paint. The prototype, constructed of transparent acrylic with a hemisphere radius of 100 mm and an absorber plate of 90 mm, includes an upper perimeter ring that increases water retention capacity to 550 ml. The research combines experimental tests under real conditions in Dolores Hidalgo, Guanajuato (lat. 21.1687°; long. −100.9339°) with measurements of temperature, relative humidity, and thermal analysis by infrared camera to evaluate heat distribution and evaporation rate. Preliminary results show a more homogeneous heat distribution on the coated plate and a significant increase in volumetric productivity, reaching 150 ml·h⁻¹ with an initial 550 ml in the tray. Likewise, it is identified that the maximum percentage of evaporation occurs with an initial 100 ml. Empirical models are proposed that relate productivity (R, mL·h⁻¹) and the percentage of evaporation (%) to the initial volume V (ml).
  Preliminary findings indicate that copper coating promotes thermal conductivity and homogeneity, which increases heat transfer efficiency and evaporation rate. Experimental limitations and recommendations for the next stage are discussed: quantitative comparative tests, geometric optimization, and verification under different solar radiation conditions.