The present study aimed at performing a hydrodynamic analysis of the safety device's behavior in a gas relay, using computational fluid dynamics techniques and experimental data validation obtained in a protective relay pilot unit (PRP) using different safety flaps geometries for fault detection within high-power transformers. The proposed methodology was carried out in four stages: (i) development of computational meshes from the three-dimensional geometry of the protective relay and safety flaps; (ii) specification of the physical properties of fluids, boundary conditions, and fluid dynamic models; (iii) obtaining speed profiles, flap angle, oil flow and system pressure difference; and (iv) comparison of simulated and experimental data. The devices installed in the relay showed satisfactory performance for failures caused by the oil volumetric expansion. It was observed that from the flap 10° tilt, the orifice ceases to be the preferred path oil, reducing detection sensitivity of the flow. Using the CFD (computational fluid dynamics) computational tool, it was possible to understand the flow behavior within the relay, allowing to detect quickly and efficiently cases of failure with oil expansion.

本研究旨在对气体继电器中的安全装置的行为进行流体动力学分析，使用计算流体动力学技术和在保护继电器先导单元 (PRP) 中获得的实验数据验证，使用不同的安全瓣几何形状进行大功率故障检测变压器。所提出的方法分四个阶段进行：(i) 从保护继电器和安全襟翼的三维几何形状开发计算网格；(ii) 流体物理特性、边界条件和流体动力学模型的规范；(iii) 获得速度曲线、襟翼角、油流量和系统压差；(iv) 模拟数据和实验数据的比较。安装在继电器中的装置对于因油体积膨胀引起的故障表现出令人满意的性能。据观察，从襟翼倾斜 10° 开始，孔口不再是首选的油路，从而降低了流量的检测灵敏度。使用 CFD（计算流体动力学）计算工具，可以了解继电器内的流动行为，从而能够快速有效地检测油膨胀故障情况。