Study and Evaluation of the Effect of Exhaust Heat Recovery Tube Structure on the Efficiency of Heat Recovery in a Sea Water to Fresh Water Distillation System ☆

Energy and fuel are the most important factors affecting the progression of country worldwide. However, fossil fuel reserves were forecasted that it will be exhausted in the near future. Therefore, managing and improving energy usage efficiency has been a major challenge. Regarding Internal Combustion engine, utilizing waste heat sources (from coolant, exhaust gas) is a simple but effective method on improving the engine heat efficiency. This paper will demonstrate the simulation research results by Ansys Fluent program to optimize the exhaust heat recovery tube structure in the utilizing exhaust and coolant heat to distill fresh water from sea water system. The outcomes show that the heat exchange area and heat transfer coefficient are two important parameters, which directly affect the heat recovery efficiency. With a reasonable structure, the exhaust heat recovery efficiency can archive 10.44%, thus heat usage efficiency of Internal Combustion Engine can increase from 32.09% to a peak of 42.53%. In addition, predicting the heat recovery efficiency will be a fundamental base of the upcoming researches to determine other specifications of the sea water to fresh water distillation system.