Fresh Water Generator Smart Chemical Dosing System

Abstract

Onboard merchant vessels, the efficient utilization of waste energy is essential, particularly for the generation of freshwater. To achieve this, ships are typically equipped with freshwater generators (distilling plants) that operate using waste heat from engine operations. The main advantage of using onboard distillation systems is the significant reduction in operational costs by minimizing dependency on shore-based freshwater supplies, while simultaneously maximizing energy recovery from waste heat. This study focuses on the importance of chemical dosing in maintaining the performance and efficiency of the distilling plant. The findings of the research highlight three key factors affecting system efficiency which is reduction in freshwater production caused by improper dosing and system fouling, salt deposit formation (scaling) on the evaporator plates, which hinders heat transfer and reduces efficiency. To mitigate this, the plant must be operated within the optimal temperature range of 35°C to 45°C to minimize the risk of excessive evaporation and foam formation. Lastly, key factor affecting efficiency is lack of operator knowledge and training, which often results in poor maintenance practices and suboptimal chemical dosing, ultimately affecting the long-term performance of the system. The integration of automated chemical dosing systems is recommended to improve operational stability, reduce maintenance costs, and ensure reliable freshwater production onboard.