Experimental investigation of a double slope active solar still: Effect of a new heat exchanger design performance. (5th November 2020)

• Record Type: Journal Article
• Authors: Mohammadi, Kamran; Taghvaei, Hamed; Rad, Ebrahim Goshtasbi
• Is Part Of: Applied thermal engineering. Volume 180(2020)
• Publication Date: 2020-11-05
• Subjects: Solar still -- Solar energy -- Desalination -- Heat exchanger -- Constructal theory -- Parabolic trough collector; Heat engineering -- Periodicals; Heating -- Equipment and supplies -- Periodicals; Periodicals; 621.40205
• DOI: 10.1016/j.applthermaleng.2020.115875
• Languages: English
• ISSNs: 1359-4311

Abstract

Graphical abstract: Highlights: Average brine temperature is about 3 °C higher in the system with NDHE. The highest overall efficiency of 39.4% is obtained using the NDHE. Using the new heat exchanger increased the distillate production by 34.1%. Lower pressure drop of HTF was obtained using NDHE. Using the new heat exchanger leads to better thermal performance of the still. Abstract: Heat exchanger design is one of the most important design parameters, which affects the performance of active solar stills equipped with heat exchanger. However, up to the present, there is a limited number of experimental studies investigate the impact of this parameter. The present work aims to study the integration of a novel designed multi-scale heat exchanger to active solar still coupled with a parabolic trough collector experimentally. This novel design is based on the practical implications of the constructal theory. The performance of the proposed heat exchanger is then compared with the conventional ones such as parallel channels and serpentine heat exchangers. Total distillate production of active solar still integrated with new heat exchanger is 34.1% and 30.4% higher than the stills integrated with parallel channels and serpentine heat exchangers, respectively. Furthermore, the highest overall energy efficiency of 39.4% was obtained utilizing the novel design heat exchanger. The enhancement in distillate production and efficiency for the still with the new design heat exchanger is in fact due to the higher brine temperature, the higher temperature difference between brine (i.e. evaporation surface) and the condensing surface, lower pressure drop, and consequently higher volumetric flow rate of heat transfer fluid.