Thermodynamic analysis of a hybrid novel solar powered humidification-dehumidification coupled with direct contact membrane distillation system

Abstract

Water scarcity is a well-known global issue, and obtaining potable water in many regions is challenging. Some technologies exist but require high-grade energy for freshwater production, which is not universally accessible. This work emphasizes desalinating saline water using low-grade energy, such as solar energy. The study introduced a novel design of hybrid solar-powered humidification-dehumidification coupled with direct contact membrane distillation (HDH-DCMD), including modeling heat transfer, mass transfer, and fluid flow. The obtained results are further validated against previously published findings. Additionally, a thermodynamic analysis of the hybrid system was conducted to examine the effects of several parameters, including variation in membrane area, top brine temperature (TBT), feed temperature, mass flow rate ratio (MR), and dimensions of the membrane module. The objective was to assess the influence of these factors on the overall distillate production, gain output ratio (GOR), and recovery ratio (RR). The hybrid system offers a significantly improved solution, yielding nearly double the distillate production and GOR compared to standalone HDH and DCMD systems. The performance of HDH and DCMD is interconnected, meaning that if one outperforms the other, the overall output remains constant. The overall distillate production remains unaffected by MR, while GOR is influenced by it, resulting in varying optimal points depending on the specific operating parameters. It has been observed that increasing the TBT results in an increase in distillate production, RR, and GOR. However, when the feed temperature increases, the distillate production and RR remain almost constant while the GOR continues to increase.