Evaluation of a rough-surface evaporator applied to an absorption heat transformer for water desalination

Abstract The purpose of this work is to evaluate the performance of a rough-textured evaporator applied to a single-stage absorption heat transformer for water desalination (SAHT-WD). The stainless-steel evaporator was subjected to an abrasive material release treatment (sandblast texture) to provide a texture that fosters phase change heat transfer compared to a smooth surface. To determine the performance of the evaporator, the evaluation has been divided into an experimental and a theoretical analysis. The experimental analysis focused on determining the operating conditions that favor the performance of the evaporator and the SAHT-WD. For the theoretical analysis, a mathematical model was developed to predict the wetting efficiency and the heat-transfer coefficients of the evaporator. To quantify the improvement in the performance of the rough-surface evaporator, the experimental results were compared with those reported in a reference work. The results indicate that the sandblasted texture improved the performance of the evaporator as well as that of the SAHT-WD. The results of the mathematical model suggest that the rough tube improved the wetting efficiency of the evaporator.