基于变质量热力学的油舱气相区动态模型

根据变质量系统热力学原理,基于浓度边界层理论作出油舱气相区中舱气均一性的系列假设,应用控制容积质量守恒方程、能量守恒方程和连续性方程及气体状态方程,针对液货作业建立油舱气相区数学模型。该模型普适于表征各种液货作业过程油舱中舱气组分、压力和温度等参数的变化。研究表明,气相状态受到液货作业行为及环境因素的扰动,具体行为取决于液货装卸、惰气充注、透气速率、环境温度和货物物性参数等。该研究为气相状态安全控制和液货作业优化提供了理论依据。

Dynamic Model of Oil Tank Ullage Space Based on Variable-Mass Thermodynamics

Based on thermodynamics principle of multi-component and variable mass system and hypothesis on concentration boundary layer,a mathematical model of oil tank ullage space is established for liquid cargo operation by applying mass balance law,energy balance law,continuity equation and state equation in the thermodynamics system.The model adopting Lumped method can characterize hydrocarbon gas concentration,oxygen concentration,pressure and temperature of vapor/gas phase during cargo operation.It's manifested that the behavior of vapor phase is disturbed by liquid cargo loading/unloading speeds,inert gas charging and venting,environmental temperatures and features of liquid cargo etc.,the mechanism of mass,heat and momentum transfer between vapor phase of oil tank and surroundings are figured out.This study provides a theoretical basis for controlling vapor phase safely and optimizing cargo operation.