Study On Ventilation And Air Conditioning Scheme For Underground Workshop Of Seawater Pumped Storage Power Station

In recent years,under the background of vigorously promoting the comprehensive utilization of seawater resources in China,the construction of seawater pumped storage power station has become imperative.The workshop of seawater pumped storage power station is buried deep underground,with strong closure degree and high salt content in outdoor air.If the ventilation and air conditioning system is not designed reasonably,problems such as humidity and stuffiness,equipment corrosion and poor air quality are likely to occur in the underground workshop.At present,there is no seawater pumped storage power station in operation in the world.Therefore,it is necessary to study the ventilation and air conditioning system scheme of the underground building of seawater pumped storage power station.The determination method of ventilation and air conditioning parameters in the workshop and the selection of system scheme are analyzed,and the airflow path is reasonably arranged to provide a good working environment for the underground workshop.Considering the heat and humidity exchange process between underground air duct and outdoor fresh air,the calculation method of indoor and outdoor air design parameters for ventilation and air conditioning in underground plant of seawater pumped storage power station is analyzed.In view of the high salt content in the air around the power station,it is necessary to control the salt spray of the fresh air entering the plant,the existing filter technology of salt spray removal is described,and the calculation method of the design parameters of indoor and outdoor salt spray is discussed.This paper studies the types of harmful gases in underground powerhouse and the fresh air volume required to remove them,and analyzes the minimum demand for fresh air volume in underground powerhouse.In this paper,two kinds of ventilation and air conditioning schemes suitable for the underground building of seawater pumped storage power station are put forward,namely,the direct flow scheme and the small fresh air scheme,and the design process and parameter determination of each scheme are analyzed.Taking the initial investment,operation cost and scrap cost of the system as the objective parameters,the life cycle cost calculation model of the ventilation and air conditioning system was established,which was used for economic analysis of each scheme.With Dawanshan Island Sea Water Pumped Storage Power Station underground powerhouse,calculation of thermal and moisture load in factory building and indoor and outdoor air design parameters,the whole life cycle cost model of once-through plan are calculated respectively,and the small new wind come to the conclusion that small new wind scheme is more economic.In view of the problem of air distribution in the main function room of the underground plant of seawater pumped storage,the research method of air distribution in the underground plant of hydropower station is summarized in this paper,and CFD numerical simulation is adopted to study it.Then,the theoretical basis of CFD numerical simulation is expounded,and the physical modeling,mesh division,mathematical model and discrete equation selection,boundary condition setting and convergence judgment in the simulation process are discussed.In this paper,CFD is used to simulate the airflow distribution in the main area of the underground powerhouse of Dawanshan Island Seawater Pumped Storage Power Station.Variables in the simulation condition mainly include ventilation and air conditioning scheme,air supply mode and air supply speed.According to the simulation results,the air distribution in the indoor work area was analyzed by using the non-uniformity coefficient,energy utilization coefficient and other evaluation indexes,and the recommended air distribution design scheme was proposed.