In this work, we focus on the influence of fouling on characteristics of a plate heat exchanger in single-phase convection and on nucleate boiling heat transfer on structured surfaces, as well as on remaining useful life prediction based on degradation of heat transfer effectiveness. For this purpose, we present experimental measurements of salt crystallization in a plate heat exchanger, coupled for the first time with infrared thermography to analyse spatiotemporal changes of heat transfer. In different operating regimes, we show local changes of the cold-water temperature field and identify the areas where the largest fouling deposit is formed. Afterwards, we demonstrate the development of structured surfaces that promote nucleate boiling heat transfer and inhibit fouling deposition. Surfaces are evaluated during long-term boiling in a clean and fouled fluid, where the degradation mechanisms and changes in surface chemistry, topography and wettability are analysed. In both fluids, we demonstrate up to ten times slower degradation of heat transfer effectiveness compared to the untreated surface and up to 112 % higher heat transfer coefficients, even after more than 400 hours of intense boiling. Finally, we present the development of an adaptive algorithm for remaining useful life prediction, the broad applicability of which is verified on experimental data of heat transfer degradation of a plate heat exchanger and of various boiling surfaces.
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