建模 氢 Dispersion Mitigation in an Enclosed Space

Background

氢, a pivotal element in the net-zero 能源 transition, finds its applications spanning across 能源，民用基础设施，以及 运输. 集装箱化的发电厂, offering mobile and modular green hydrogen solutions, are increasingly adopted for remote applications. 然而, the unique properties of hydrogen – such as a wide flammability range, 一种无色无味的火焰, 高扩散率, being lighter than air – elevated the risk of hydrogen dispersion in confined spaces.

这个案例研究展示了如何 数字工程 利用 计算流体动力学(CFD) 模拟，以加强 安全评估 of mobile containerized workshop units servicing hydrogen fuel cells in remote power applications. The workshop in question features a pressurized 35-bar hydrogen supply pipe, posing a potential risk for hydrogen dispersion due to leakage. 已安装的泄漏缓解系统, equipped with a shutoff valve and an extraction fan driven by 气体 detection sensors, 旨在管理这种风险. The failure scenario analyzed involves a full-bore hydrogen feed pipe failure, leading to pressurized hydrogen dispersion into the workshop unit.

A critical aspect under review was the sensor placement’s efficacy in ensuring the leak mitigation system’s performance, crucial for keeping hydrogen concentrations below 25% of the Lower Explosive Limit (LEL) throughout the event, thereby minimizing the risk of hydrogen dispersion.

所面临的挑战

The core challenge addressed in this study was understanding the implications of a pipe failure event on system performance, particularly concerning pressurized H2 气体 release into an unventilated, sealed room and its subsequent hydrogen dispersion. Accurately predicting the dynamics of the hydrogen 气体 jet at the leak source and the 气体 plume’s behavior, 尤其是靠近天花板的地方, 是很重要的. 这需要对气体检测过程进行建模, 激活安全机制, and key outcomes like the residence time and concentration of the hydrogen 气体 cloud, providing insights into the overall efficacy of the safety system against hydrogen dispersion.

解决方案

数字工程 boasts a wealth of experience in employing 计算流体动力学(CFD) for assessing the safety and performance of critical engineering systems across sectors. This expertise extends to simulating 气体 dispersion and 气体 cloud explosion scenarios, 包括氢分散. 利用商业CFD代码 西门子STAR-CCM+, 该小组将泄漏事件模拟为不稳定, 动荡不安的, 和可压缩的多组分气体流, enabling an accurate depiction of hydrogen dispersion within the container environment. Adaptive mesh refinement methods and custom field functions modeled the safety systems’ response to detected hydrogen concentrations, 将激活阈值设置为25% LEL.

结果

The analysis successfully predicted the pipe failure scenario’s consequences, underscoring the hydrogen dispersion risk – a vital input for the system’s overall safety evaluation. The simulation revealed that the failure produced a high-velocity jet, 在天花板附近形成了一个集中的H2云, with the central sensor’s detection and mitigation system activation occurring within approximately 19 seconds of hydrogen dispersion. This CFD simulation capability facilitated a cost-effective virtual verification of the mitigation system’s effectiveness against hydrogen dispersion, 作为一个重要的风险管理工具. The insights gained also informed the optimization of sensor placement, enhancing system performance and coverage against hydrogen dispersion scenarios.