Studies On Natural Ventilation Network Simulation And Application Of The Underground Excavation Cluster Of Hydropower Station

Natural ventilation in the mine has been forbidden in China because of the security, while it is popular in the world. Now hydropower stations have been constructing on a large scale in our country. So the problem whether natural ventilation can be used in the underground excavation cluster of hydropower station urgently needs to be solved. This paper carries on the research systematically, establishes analyses method based on network model about the natural ventilation in the underground excavation cluster of hydropower station, reveals natural ventilation's mechanism and characteristics in the underground excavation cluster of hydropower station, demonstrates natural ventilation's feasibility in the national important project- Xiaowan underground hydropower station, and brings forward a new viewpoint that natural ventilation should be adopted firstly in the underground excavation cluster of hydropower station.This paper puts forward the concept and method about the network graphics of underground excavation cluster of hydropower station firstly. Confirms the property of the network graph's elements; establishes the concept about network graph's rank; brings forward rank combination's analysis method; offers the basic method about the network graph of underground excavation cluster of hydropower station referring to actual project; puts forward the concept about the fringe node; and proves the number and the connecting method about the atmospheric virtual embranchment. Additionally, puts forward the concept about the impedance value U of the embranchment of the network and the theory and the method about the model experiment; gains the pressure distribution of the key places of the underground excavation cluster of Xiaowan hydropower station and the impedance value U of the key embranchment by the model experiment.And then establishes the natural ventilation network model about the underground excavation cluster of hydropower station with network graph which includes the network flow model,network temperature model and network heat pressure model. Puts forward the concept of the embranchment heat pressure,embranchment temperature distribution model, and the calculation method about the embranchment heat pressure. And brings forward the concept about network temperature model, sets up universal equations about the network temperature, educes their matrix expressions, and proves...