压力容器泄放过程建模与仿真分析

Modeling and simulation analysis of relief process of pressure vessel

关键词:  压力容器  气体组分  物性参数  AGA8状态方程  动力学模型

Key words:  pressure vessel  gas component  physics property  AGA8 equation of state  dynamic model

摘要:

在石油化工领域压力容器被广泛应用于存储和运输压缩气体。在特殊工况下,需要将压力容器气体进行泄放,以保证设备和管路的安全。基于热力学第一定律、质量守恒和AGA8状态方程,建立了压力容器泄放过程的动力学模型,分析了容器内气体压力、温度、压缩因子和绝热指数等参数的变化规律,研究了外界温度、气体组分和孔板面积对泄放时间的影响,给出了计算孔板直径的方法。结果 表明,泄放过程中,压缩因子和绝热指数是变值,气体组分对泄放时间有明显的影响,在仿真计算时应该充分考虑。泄放时间随外界温度升高而增加。该研究结果可以为压力容器放空系统的设计和优化提供参考和帮助。 

Abstract:

In petrochemical field, the pressure vessels are widely applied for storing and transporting compressed natural gas. In order to guarantee the safety of equipment and pipeline, the gas filled in the pressure vessels should be released under some special conditions. Based on the first law of thermodynamic, mass balance and AGA8 equation of state, a novel dynamic model was established to stimulate the relief process in this paper. According to this model, the variation of the compressor parameters, such as pressure, temperature, compressor factor and adiabatic index were predicted. Meanwhile, the influences of external temperature, gas component and orifice area on discharge time were investigated. Besides, a method for calculating orifice diameter was presented. The simulation results showed that the compressor factor and adiabatic index are variables and the gas component has significant effect on discharge time, which should not be ignored in calculations. Moreover, the discharge time increased with the elevation of the external temperature. All the above findings could provide reference and support for the design and optimization of the pressure vessel vent system.