Study On Dust Removal And Ventilation System Of Underground Caverns In Pumped Storage Power Station

Fengning Pumped Storage Power Station is located in Fengning Manchu Autonomous County,Chengde,Hebei Province.Its planned installed capacity is 3600 MW.It is the largest Pumped Storage Power Station under construction in the world.During the construction of underground cavern excavation,the working environment of excavation face is poor,dust and blasting smoke can not be eliminated in time,which seriously affects the health of the constructors and the progress of the project.The conventional treatment method is to use ventilators with air ducts to supply air to the construction tunnel in order to transport fresh air and reduce the concentration of pollutants.But in the process of dilution and diffusion of pollutants,the whole cavern will be polluted and the workers and working environment in the cavern will be endangered.In addition,the use of fans is accompanied by high electricity costs.Taking the underground caverns of Fengning Pumped Storage Power Station as the research background,by means of theoretical analysis,numerical simulation and engineering test,the ventilation and smoke dissipation during tunnel construction are separated and studied.The main achievements are as follows:A movable tunnel smoke and dust purification system has been developed and tested on the construction site of the main powerhouse of Fengning Pumped Storage Power Station.The results show that the system has high mobility,simple operation system and good dust removal effect.It can reduce the smoke and dust concentration effectively,improve construction efficiency and reduce energy consumption,and can be widely used in similar projects.Combining with engineering data,the ventilation system of underground caverns in Fengning Pumped Storage Power Station during construction period is planned by stages,and the ventilation situation of underground caverns in different construction periods is simulated by computational fluid dynamics(CFD).According to the calculation results,the flow and dust distribution law of underground caverns are obtained.According to different ventilation stages of caverns,the ventilation system of underground caverns in Fengning Pumped Storage Power The corresponding ventilation optimization suggestions are put forward.The permanent ventilation law of Fengning Pumped Storage Power Station's underground caverns under different ventilation schemes during the operation period is simulated.The operation law of the permanent ventilation of the caverns and theventilation efficiency of the ventilation shaft under different space locations are obtained.The optimal ventilation shaft arrangement mode to satisfy the ventilation of the underground caverns is given,and the corresponding optimization suggestions of the permanent ventilation system are put forward,so as to pump water for Fengning.The design of ventilation system for underground caverns in storage power station during operation period provides theoretical support.Through the study on the smoke and ventilation system of underground caverns in Fengning Pumped Storage Power Station,the problem of dust during construction is solved,the construction environment and the health of workers are guaranteed,and the reference is provided for the ventilation design of related hydropower projects.