Abstract:

In carbon capture and storage (CCS) technology, CO₂ is transported from the capture point to the storage point primarily through high pressure piping. The potential for pipeline rupture and leakage, possibly resulting in catastrophic accidents, will presents a risk to human and animal populations. Therefore, to ensure pipeline safety, an essential risk assessment involving an accurate prediction of CO₂ pipe flow following the pipeline fracture, especially obtaining the conditions at rupture, provides effective technical support for the implementation of large-scale CCS projects and contribute to pipeline safety. In the present paper, a one-dimensional (1D) Computational Fluid Dynamics (CFD) pipe flow model to predict pipeline fracture is developed. Precise Equation of States (EOSs), PR and GERG, is used to achieve more accurate source strength estimates. The effects of friction and heat transfer through the pipe wall are accounted for through momentum and energy source terms. The model is applicable for both single-phase and gas-liquid two-phase flow. In terms of two-phase simulation, liquid/vapour transition is implemented by introducing mass and energy source terms. The model predictions are validated by data from three independent depressurization experiments. Also, the effects of pipe wall roughness and pipe diameter on mass outflow rate are investigated. This research helps provide a reliable method for risk assessment related to CCS.

Key words: gas-liquid?flow, phase transition, carbon capture and storage, computational fluid dynamics, equation of state

摘要：

在碳捕捉和储存（CCS）技术中，CO₂主要通过高压管道从捕获点输送到储存点。一旦发生管道破裂引起泄漏，管道破裂条件、泄漏量大小与事故后果直接相关。因此，为了确保安全，必须对管道破裂后CO₂管道流量等进行准确预测，特别是获取破裂条件，为大规模CCS项目的实施提供有效的技术支持。建立了一维（1D）计算流体动力学（CFD）管道破裂减压预测模型，通过使用精确的状态方程(PR,GERG)来实现更好的源强度估计。摩擦和传热的影响是通过动量和能量项来实现的。该模型适用于单相和气液两相减压流动。在两相模拟方面，通过引入质量和能量项来实现液/气转变。通过三个独立的减压流动实验验证了模型预测。此外，还研究了管壁粗糙度和管径对泄漏流量的影响。这项研究有助于提供一个可靠的与CCS相关的风险评估方法。

关键词: 气液两相流, 相变, 碳捕捉技术, 计算流体力学, 状态方程