Thermal analysis of a conical solar still performance: An experimental study

• Conventional and conical solar stills have been experimentally compared.
• Detailed experiments have been conducted under a wide range of weather conditions.
• The productivity of conical still is higher than that of the conventional still.
• Correlations for the heat and mass transfer coefficients have been obtained.
• Predicted heat and mass transfer coefficients agree well with experimental values.

In this paper, an attempt is made to estimate the heat transfer coefficients of a conical solar still. Many researches and development works tried to enhance the productivity of solar stills using different methods. So in this study the productivity enhancement of solar still by decreasing the shadow effect and maximize utilization of solar radiation is discussed. A conical solar still was designed and manufactured at faculty of engineering Sheben El-Kom – Egypt (latitude 30.56 N and longitude 31.01 E). The still base area was 0.8 m2, and the acrylic cover of still inclined at 31° which equal to the city latitude. The experimental results of conical solar still were compared with a conventional type solar still which has the same area. The results showed that, the daily productivity for conical and conventional solar stills was 3.38 and 1.93 L/m2 day, respectively. Heat and mass transfer coefficients were evaluated and the Nusselt and Sherwood numbers were calculated with the aid of both evaporation measurements and Chilton–Colburn analogy. The maximum value of the total heat transfer coefficient were 66 and 32 W/m2 °C for conical and conventional solar stills, respectively. The analogy between heat and mass transfer coefficients was also investigated.

The heat and mass transfer in conical and conventional solar stills are investigated experimentally. It is found that the daily productivity of conical solar still is higher than that of the conventional one.Figure optionsDownload as PowerPoint slide