Comparison Between the Performance of Multi-Stage Flash Desalination Once-Through and Brine Recirculation in Extracting Marine Diesel Engines Waste Energy

There are numerous methods for utilizing waste heat energy from marine diesel engines; however, selecting these methods depends on the load and capacity of these engines, as well as the available area. As a result, the purpose of this paper is to utilize waste heat energy from scavenge air to operate the multi-effect evaporator forward feed (MEE-FF) and assess its performance based on the distillate water’s mass flow rate at various engine loads. A comparison is also made between the multistage flash desalination once-through (MSF-OT) and multistage-desalination brine recirculation (MSF-BR) to determine which is best in extracting engine exhaust waste energy within the available area. Detailed mathematical models were built for three different plants using MATLAB software. On these plants, the effect of various variables like steam temperature, intake water flow rate, and the temperature on the plant performance have been studied. The main result showed that the performance ratio, surface area and distilled mass amount in the MSF-BR are increased by 55%, 50.19%, and 55% for the same input data respectively, while the feed water mass and brine mass are decreased by 50.87% and 34.36%, respectively in comparison to MSF-OT.