Improving the tubular solar still performance using square and circular hollow fins with phase change materials

Abstract

Tubular solar still has large evaporative and condensing surface areas compared to the conventional single slope solar still. The current study aims at improving the performance of the tubular solar still via additional performance improvers. The array of copper hollow fins was fitted on the absorber surface. In addition, PCM reservoir was installed below the absorber surface to extend the time of distilled water production after sunset. To experimentally investigate the effects of copper hollow fins shape and PCM on the performance of tubular solar still, two experimental scenarios were studied. In the first experimental scenario, the effects of copper hollow fins shape were studied. To investigate this idea, the traditional tubular still, tubular solar still with hollow square fins, and tubular solar still with hollow circular fins were tested at the same climatic conditions. In the second experimental scenario, the effect of copper hollow circular fins and PCM was studied. To investigate this idea, traditional still and tubular solar still with hollow circular fins and PCM were tested at same environmental conditions. The results showed that the traditional tubular still produced accumulated productivity of 4.15 L/m2/day, while the hollow square fins utilization improved the productivity to 5.52 L/m2/day with 33% improvement. Besides, the hollow circular fins utilization improved the productivity to 6.11 L/m2/day with 47.2% enhancement. Additionally, the PCM with hollow circular fins increased the accumulated productivity to 7.89 L/m2/day representing a 90.1% improvement. A comparison between the present modifications with previous studies in Egypt showed that the tubular solar still with hollow circular fins and PCM has an effective and distinctive performance.