Modeling of Cryogenic Liquefied Natural Gas Ambient Air Vaporizers

Abstract

Ambient air vaporizers (AAVs) are used to vaporize cryogenic liquefied natural gas (LNG) using the ambient air as a heat source, offering an economical and environmentally friendly alternative to combustion-based vaporization. This study investigates the thermal-hydraulic performance of AAV systems using computational fluid dynamics (CFD) to support improved design and operation.

The research analyses heat transfer between ambient air and cryogenic LNG under supercritical flow conditions from a thermodynamic perspective. Since actual LNG flow data was unavailable for direct validation, the CFD model was validated using empirical correlations and experimental data from supercritical flows of water and carbon dioxide as surrogate fluids. The validated model was then applied to investigate supercritical LNG flow inside AAV units across various operating conditions including ambient air flow velocity and operating pressure. The study optimises fin configurations by systematically investigating the effects of the number of fins, fin length, and fin thickness on heat transfer performance. The methodology and results provide critical insights for designing AAV systems with improved thermal efficiency and reduced susceptibility to frost formation and performance degradation under various operating conditions.

@article{sun2018modeling,
  title         = {Modeling of Cryogenic Liquefied Natural Gas Ambient Air Vaporizers},
  author        = {Sun, Biao and Wadnerkar, Divyamaan and Utikar, Ranjeet P and Tade, Moses
                  and Kavanagh, Neil and Faka, Solomon and Evans, Geoffrey M and Pareek, Vishnu K},
  year          = 2018,
  journal       = {Industrial \& Engineering Chemistry Research},
  publisher     = {American Chemical Society},
  volume        = 57,
  number        = 28,
  pages         = {9281--9291}
}