Thermal resistance analysis of cryogenic frosting and its effect on performance of LNG ambient air vaporizer

摘要

Liquefied natural gas (LNG) ambient air vaporizer (AAV) utilizes renewable energy from ambient air (aerothermal energy) to evaporate LNG in gas terminal stations. Frost may occur on the AAV surface due to cryogenic LNG, leading to poor heat transfer performance. This paper presents a numerical analysis of the thermal resistance of cryogenic frost layer and its effect on the heat transfer coefficient of the air side of AAV. The air temperature near the cryogenic fin tube surface differs from the ambient air and was modified by a three-dimensional integrated model of AAV. An experimental test of the thickness of the frost layer on the MV fin tube was conducted to validate the numerical model of the frost formation, and the test data agrees well with the numerical results. The results show that a "valley heat transfer coefficient temperature" exists under frost conditions, which is the corresponding air temperature of the minimum heat transfer coefficient of MV. (C) 2019 Elsevier Ltd. All rights reserved.