Advanced M-Cycle System for Simultaneous Cooling and Water Desalination

Abstract

Access to safe drinking water and a healthy living environment is essential for human survival. With growing populations and decreasing availability of potable water, producing safe water from non-drinkable sources has become increasingly important. One effective method to achieve this is through water desalination. Among desalination techniques, humidification and dehumidification stand out as simple, low-cost, and portable solutions that do not require advanced equipment. These systems can be integrated with other technologies to fulfill multiple needs. One such integration involves air conditioning systems, where the innovative M-cycle concept has shown great promise. This cycle can cool air to its dew point without humidification and without using environmentally harmful refrigerants – essentially, water acts as the working fluid.

In this study, an M-cycle-based cooler has been creatively modified to generate fresh water alongside cooling the air, serving both desalination and air conditioning purposes. A comprehensive mathematical model has been developed and solved using finite element methods. The system's heat and mass exchanger has been optimized, and two configurations for its operation have been proposed. A new performance metric, PR (Performance Ratio), has been introduced to assess the system's dual-function efficiency.

Results indicate that an infiltration rate of 0.3 yields the highest water distillation rate and optimal cooling performance. The proposed design achieves a 9.2% higher gain-output ratio compared to conventional humidification-based desalination systems and offers 50% more cooling capacity than standard M-cycle air conditioning units, while demonstrating up to 8 times greater energy efficiency for desalination.