Thermal assessment of a direct contact membrane distillation system with integrated multiple heat recovery: A theoretical analysis

This study presents a novel approach to enhancing thermal management in direct contact membrane distillation (DCMD) systems through infrastructure development, eliminating the need for renewable energy integration, which often involves initial costs. Conventional DCMD systems with single-stage heat recovery are inadequate for dissipating accumulated heat in the cold tank during closed-loop operation, leading to inefficiencies in cooling performance. To address this limitation and improve production efficiency, a multiple heat recovery design integrated with a DCMD system is proposed. The system is evaluated through theoretical energy and exergy analyses based on previous experimental data. The proposed design significantly reduces electrical energy consumption for heating and cooling, especially at higher flow rates, which typically accounts for 67%–72% of total energy use. This enhancement optimizes system performance, reducing the exergy consumption on the cooling system by 57% and on the heating system by up to 50%, as illustrated in the Sankey diagram. Furthermore, it demonstrates the potential for improving membrane distillation (MD) system infrastructure to enhance distillate production at lower operating costs. By refining the DCMD system design with multiple heat recovery, this study contributes to more cost-effectiveness and scalable desalination technologies.