摘要
LNG空温式气化器是气化站内的核心设备,其管内气化传热特性对于设计与运行优化具有重要意义。以实际运行中的空温式气化器单根翅片管为原型,运用计算流体力学软件Fluent,采用VOF(Volume of Fluid)多相流模型及Lee冷凝相变模型,对LNG管内气化传热与流型进行了数值研究。结果表明:LNG在空温式气化器内气化的主要流型为泡状流、弹状流、搅拌状流及雾状流,且与Hewitt和Roberts流型图吻合较好;在LNG管内气化过程中,随着气相体积分数的增大,局部传热系数呈先增大后减小的趋势;管内局部传热系数随着壁面加热热流密度的增大而升高,LNG在空温式气化器内的气化传热以核态沸腾传热为主。
LNG ambient air vaporizer（AAV） is the key equipment in LNG vaporization stations, so its vaporization and heat transfer performance inside the pipe is of great significance to its design and operation optimization. In this paper, the single finned tube of AAV in service was taken as the model for study. The vaporization, heat transfer performance and flow pattern of LNG inside the pipe were numerically investigated in Volume of Fluid（VOF） multiphase flow model and Lee condensation phase change model by using the fluid mechanics calculation software Fluent. It is shown that the vaporization flow patterns of LNG in AAV are mainly bubbly flow, slug flow, churn flow and mist flow, which are in line with Hewitt and Roberts flow pattern maps. During the vaporization of LNG inside the pipe, the local heat transfer coefficient increases firstly and then decreases as the gas volume fraction gets higher. The local heat transfer coefficient inside the pipe increases with the increasing of heating flow density at the wall surface. The vaporization and heat transfer of LNG in AAV is dominantly in the form of nucleate boiling.
出处
《油气储运》
CAS
北大核心
2017年第8期918-923,共6页
Oil & Gas Storage and Transportation
关键词
LNG
气化
空温式气化器
流型
传热
LNG
vaporization
ambient air vaporizer
flow pattern
heat transfer
