The current experimental work aims to improve an accumulative yield of tubular solar distillers. This was achieved by utilizing the pin fins and external condenser coupled with the tubular solar distiller. The tubular distillers are characterized by having a large receiving and condensing surface area compared to a traditional single-slope distiller; therefore, the utilization of pin fins is very effective to increase the evaporation rate, as well as the external condenser was utilized to increase the condensation rate. In order to achieve this vision, the experimental study mainly included two axes: namely, in the first axis, the effect of utilizing the pin fins on the cumulative yield of tubular solar distillers was studied, as well as obtaining the optimal orientation of the pin fins to reduce the shadow effect generated inside the basin. In the second axis, the effect of utilizing an external condenser and the inclined pin fins on an accumulative yield of the tubular solar distiller was studied. To investigate this idea, in the first study axis, three tubular distillers were constructed and tested at the same conditions, namely conventional tubular solar still (CTSS), modified tubular solar still with vertical pin fins (MTSS-VPF), and modified tubular solar still with inclined pin fins (MTSS-IPF). In the second study axis, two tubular distillers were constructed and tested at the same conditions, namely CTSS and modified tubular solar still with inclined pin fins and condenser (MTSS-IPF+Condenser). The results presented that the enhancement in accumulative yield reached 18% and 27.6% for utilizing the vertical and inclined pin fins, respectively, as compared to CTSS. These results show that the utilization of inclined pin fins represents a good option to improve the accumulative yield of tubular distillers. Also, the accumulative yield and the daily efficiency achieved by utilization of the external condenser and the inclined pin fins (MHSS-IPF+Condenser) reached to 5.94 L/m2/day and 54.9% with an improvement of 70.2% and 71.6%, respectively, as compared to CTSS.
Keywords: Condenser; Optimum orientation; Performance improvement; Pin fins; Tubular solar still.