Experimental and Simulation Study of Solar-Powered Air-Gap Membrane Distillation Technology for Water Desalination

Area of Science:

• Renewable Energy Engineering
• Membrane Science and Technology
• Water Desalination

Background:

• Solar-powered air-gap membrane distillation (SP-AGMD) is a promising technology for water desalination.
• Temperature polarization (TP) and concentration polarization (CP) are critical phenomena affecting SP-AGMD efficiency.
• Optimizing operating conditions is essential for maximizing SP-AGMD system performance.

Purpose of the Study:

• To investigate the impact of temperature polarization (TP) and concentration polarization (CP) on SP-AGMD performance.
• To analyze the influence of various operating conditions on SP-AGMD system parameters.
• To develop and validate a mathematical model for the SP-AGMD system.

Main Methods:

• Experimental investigation and mathematical modeling of the SP-AGMD system.
• Simulation of the SP-AGMD system using TRNSYS, incorporating an evacuated tube collector (ETC) and photovoltaic (PV) system.
• Statistical analysis including one-way ANOVA and Spearman's correlation to assess the significance of operating parameters (p < 0.05).

Main Results:

• Feed flow rate (M_f) significantly impacted productivity (P_r) and heat-transfer (h_f) coefficients (p < 0.001) and temperature polarization coefficient (τ) (p < 0.05).
• Increased feed temperature (T_f) to 60 °C and feed flow rate (M_f) to 12 L/h enhanced P_r by 99% and 146%, respectively.
• Under high solar radiation (1002 W/m²), the system achieved an inlet heat temperature of 73 °C and a P_r of 1.62 kg/(m²·h).

Conclusions:

• Feed flow rate is the most influential parameter for SP-AGMD system performance.
• Optimized operating conditions, particularly feed flow rate and temperature, significantly enhance water production.
• The study provides valuable insights for improving the efficiency and productivity of solar-driven membrane distillation systems.