Steam condensation heat transfer on lubricant-infused surfaces
Ryan Stoddard, Karthik Nithyanandam, R. Pitchumani
Abstract
Steam condensation is fundamental to several industrial processes, including power generation, desalination, and water harvesting. Lubricant-infused surfaces (LISs) promote sustained dropwise condensation, leading to significantly higher heat transfer performance that trades off with durability. Here, we present a systematic study on lubricant-infused copper tubes in a partial vacuum environment typical of power plant condensers to elucidate the influence of the design parameters-texturing, functionalizing agent, and lubricant viscosity-on condensation heat transfer performance and durability. Heat transfer effectiveness is introduced as a relevant parameter to quantify the effects of condensation heat transfer coefficient enhancement on the overall system heat transfer performance. Analytical expressions are developed for lubricant retention fraction and heat transfer effectiveness in terms of Bond number, viscosity ratio, and a dimensionless logarithmic mean temperature difference that can be used for predicting the performance of a LIS or for designing surfaces for a desired performance.