Performance enhancement of a hybrid CPV/DCMD system using convergent microchannel cooling and finned DCMD feed channel

Concentrated solar energy for electricity and freshwater production constrained by thermal management in concentrated photovoltaic systems and temperature polarization in membrane distillation. In this study, a hybrid concentrated photovoltaic/direct contact membrane distillation system is numerically investigated using a sequentially coupled framework to enhance both thermal regulation and desalination performance through passive geometry induced flow acceleration. A convergent outlet microchannel heat sink is proposed for concentrated photovoltaic cooling and compared with a four compartment design, while an internally finned direct contact membrane distillation feed channel is evaluated against a wide channel configuration. The proposed microchannel reduces concentrated photovoltaic cell temperature nonuniformity by 92–94 % compared with the conventional four compartment microchannel configuration across all investigated concentration ratios, suppressing hot spots from 20.16 °C to 1.65 °C, at concentration ratio of 1000 suns and 100 mL/min, while maintaining nearly identical electrical output (difference < 0.1 %). The recovered waste heat preheats the saline feed to approximately 60 °C without auxiliary heating, defining the practical operating envelope of the hybrid system. On the other side, for the desalination unit, the proposed finned channels improve the permeate flux at 60 °C from 4.58 (i.e., for the conventional wide channel) to 6.2 kg/m²·hr, which accounts for 35 % enhancement, and improved the efficiency from 24.5 % to 35.3 %, which is 44 % enhancement. These enhancements are attributed to the temperature polarization mitigation in the feed channel. Additionally, increasing the concentration ration from 700 to 1000 showed a permeate flux improvement of 91 %, and electric power output of 39 %.