The effect of turbulence on the rate of evaporation of LNG on water

• Published in: Journal of loss prevention in the process industries 2011-11, Vol.24 (6), p.791-797
• Main Authors: Morse, Timothy L., Kytömaa, Harri K.
• Format: Article
• Language: English
• Subjects: Computational fluid dynamics; Cryogenic liquid; Evaporation; Fluid flow; Liquefied natural gas; Liquids; LNG; Measurement; Spills; Surface water; Turbulence; Turbulence intensity; Turbulent flow
• ISSN: 0950-4230; 1873-3352
• DOI: 10.1016/j.jlp.2011.06.004

The present study provides new measurements of the rate of evaporation of cryogenic liquids, liquefied natural gas (LNG) and liquid nitrogen (LN 2), floating on a water surface with different levels of turbulence intensity. The turbulent water surface is generated with an upward-pointing submerged jet with controlled jet velocity, an approach which has often been used in studies of free-surface turbulence. Direct measurements of the rate of evaporation were carried out for different pool thicknesses and turbulence intensities of the water surface. These tests reveal a strong dependence of the evaporation rate on the turbulence intensity, as well as a dependence on the thickness of the cryogenic liquid layer above the water surface. Models of LNG spills on water currently use a single rate of evaporation; these findings show that this approach is inadequate. Future models should incorporate the water turbulence intensity, and possibly the LNG spill thickness for improved accuracy. ► The evaporation rate of LNG spilled on water depends on the turbulence intensity. ► We characterize this dependence through experimental measurements. ► We find that the LNG layer thickness also influences the evaporation rate. ► Models of LNG spills should incorporate the water turbulence intensity.