Line Well Of Underground Hydropower Station Experimental And Numerical Simulation Analysis Of SF₆ Leakage Diffusion

Today's rapid social and economic development, energy has become tighter, especially the renewable, clean and stability of hydroelectric energy, so that the construction of hydropower stations in China's energy strategy is important and be concerned. The electric energy produced by the hydropower station can be conveyed through the GIL cable, and the electric power equipment will inevitably have problem or damage in the operational course of the hydropower station,electric power equipment will appear the SF6 gas leakage problem.Because the special topography and complex workshop space of underground hydropower station, the gas ventilation system is important to protect the personal safety and Normal operation of hydropower station. In Baihetan SF6 gas ventilation model experiment research project, through the method of combining similar model test and numerical simulation, studying the well cable leakage model and evaluating to the ventilation system.GIL cable exist the possibility of heavy SF6 gas leakage in the hydropower station, analyze the structural parameters of GIL, understand the pipeline leakage model, analysis the principle of heavy gas leakage and diffusion process, get the leakage calculation formula, for the next step to lay the theoretical foundation of experiment and numerical simulation analysis.Using the similarity theory, seting up similarity model, the amount of leakage according to leaked model calculations, experiment of gas leakage and diffusion process, By measuring the concentration of SF6 gas, dense gas leakage and diffusion rules, to analyze the relationship between the ventilation system and the law of diffusion, and validate the reliability and feasibility of the CFD numerical simulation method.Establish mathematical model, access CFD numerical simulation, expand the analysis and research. In the numerical simulation of various conditions, analying the influence of obstacles on the SF6 gas diffusion in the outlet of hydropower station; and GIL cable heat sinking effect on the heavy gas concentration field distribution;As well as the analysis on the SF6 gas leakage occurs normal divulge, the influence of different leakage and ventilation rate of SF6 gas diffusion; And analyzed in the normal leakage, SF6 gas concentration field distribution in each space structure, the impact of ventilation system velocity on the heavy gas dispersion,to obtain the safer more energy- efficient ventilation case in daily operation.When the cable leakage accident occurred, simulating the transient numerical simulation, analysis in different spatial structure, different ventilation rates and different leak location conditions, the limited space of SF6 concentration distribution and concentration changes over time; get safe and economical ventilation program in leakage accident conditions.Therefore, through the model experiment and CFD numerical simulation, determine the safe and economical ventilation program in outlet structure of Baihetan Hydropower Station,and to establish foundation for the ventilation scheme of the hydropower station.