ANALYSIS OF METHODS FOR INTENSIFYING HEAT TRANSFER IN SHIP FRESHWATER GENERATORS

Abstract

This article investigates the problem of improving energy efficiency and reducing operating costs of vacuum-type freshwater generators used in modern shipping. Tubular heat exchangers employed in seawater evaporation and condensation processes are considered as the main object of the study. The combined effect of passive methods (Annularly corrugated tube) and active methods (low-frequency flow pulsation) on the hydrodynamic regime and heat transfer performance has been examined. Based on theoretical and experimental analyses, it has been established that the proposed method ensures turbulence enhancement in the boundary layer, allowing the Nusselt number (Nu) to increase by  times compared to the initial operating configuration of the unit. As a result of accelerated heat transfer, it becomes possible to use smaller and more compact units to produce the same amount of freshwater, which enables significant space savings in the ship engine room. In addition, maintaining the cleanliness of the internal tube surfaces eliminates the need for frequent shutdowns for maintenance or chemical cleaning. At the same time, the non-stationary flow regime significantly reduces the intensity of scale (salt deposit) formation on heat transfer surfaces, thereby further enhancing heat transfer efficiency.

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