Mathematical modeling and experimental validation for square pyramid solar still

Area of Science:

• Renewable Energy Engineering
• Thermal Engineering
• Solar Energy Conversion

Background:

• Solar stills are crucial for freshwater generation.
• Accurate thermal modeling is essential for optimizing solar still efficiency.
• Previous studies often lack detailed mathematical models for pyramid solar stills.

Purpose of the Study:

• To develop and validate a detailed mathematical model for a square pyramid solar still.
• To investigate the thermal performance and daily productivity of the solar still.
• To analyze the impact of key design parameters on the still's efficiency.

Main Methods:

• Development of computer programs in Pascal for thermal analysis.
• Estimation of hourly solar intensity on tilted covers.
• Validation of the mathematical model through comparison with experimental data.

Main Results:

• The daily productivity (Pd) ranges from 4.22 to 4.43 kg/m² day with tilt angles of 10°-60°.
• Productivity decreases from 3.88 to 1.52 kg/m² day as water depth increases from 0.01 to 0.30 m.
• Top heat losses decrease with increasing glass cover surface area and tilt angles.

Conclusions:

• The proposed mathematical model accurately predicts the performance of pyramid solar stills.
• Optimal tilt angles and water depths can significantly enhance daily productivity.
• Understanding thermal losses is key to improving solar still design and efficiency.