Numerical simulation of flow and heat transfer characteristics of LNG cryogenic corrugated hoses

Abstract

LNG corrugated hoses have better flexible mechanical properties and compliance. However, due to the influence of its outline structure and the large heat transfer coefficient, large heat loss is caused during LNG transportation, with the transportation efficiency reduced. Therefore, the flow and heat transfer characteristics of LNG in the plain tube and the corrugated hoses with 5 types of different structural parameters were analyzed with the numerical simulation method. Meanwhile, the influence laws of the corrugation depth,corrugation pitch and Reynolds number on the heat transfer characteristics of the hoses were explored, and the heat transfer characteristics of the hoses were characterized with the thermal performance evaluation criterion(PEC). The results show that: The corrugated hoses have higher Nusselt number, greater friction coefficient and better heat transfer characteristics than the plain tubes. The Nusselt number in the corrugated hoses increases with the increase of Reynolds number, while the friction coefficient decreases with the increase of Reynolds number and becomes stable at high Reynolds number. Under the same Reynolds number, the Nusselt number of the corrugated hoses increases with the increase of the corrugation depth, but decreases with the increase of the corrugation pitch. Besides, the friction coefficient is proportional to the change of the corrugation depth and pitch, and the corrugation depth has the greatest influence. Generally, the research results could provide theoretical guidance for the engineering application and the structural optimization design of LNG cryogenic corrugated hoses.

Keywords

• lng
• cryogenic corrugated hose
• plain tube
• heat transfer performance
• flow characteristics
• numerical simulation