Under forced ventilation,the dust diffusion of underground powerhouse construction is investigated using a 3D high Reynolds number k-ε model.The interfacial momentum transfers and the wall roughness in the wall funct...Under forced ventilation,the dust diffusion of underground powerhouse construction is investigated using a 3D high Reynolds number k-ε model.The interfacial momentum transfers and the wall roughness in the wall function are considered.Ventilation in the third layer of underground powerhouse of Xiangjiaba hydropower station is used as a case.The geometric structure has a decisive effect on the airflow distribution.It is concluded that the dust concentration decreases gradually with the increase of the ventilation time.However,iso-concentration curves have the same tendency after 1 800 s.The dust concentration meets the ventilation and dust-prevention health standard after 2 300 s.The prediction by the present model is confirmed by the experimental measurement by Nakayama.展开更多
At the Mont Terri Underground Research Laboratory （Switzerland）, a field-scale investigation has been conducted in order to investigate the hydro-mechanical and chemical perturbations induced in the argilla- ceous f...At the Mont Terri Underground Research Laboratory （Switzerland）, a field-scale investigation has been conducted in order to investigate the hydro-mechanical and chemical perturbations induced in the argilla- ceous formation by forced ventilation through a tunnel. This experiment has been selected to be used for processing model development and validation in the international project DECOVALEX-2011. The con- ceptual and mathematical representation of the engineered void, which itself forms a major part of the experiment and is not simply a boundary condition, is the subject of this paper. A variety of approaches have been examined by the contributors to DECOVALEX and a summary of their findings is presented here. Two major aspects are discussed. Firstly, the approaches for the treatment of the surface condition at the porous media/tunnel interface are examined, with two equivalent but differing formulations successfully demonstrated. Secondly, approaches for representing the tunnel with associated air and water vapour movement, when coupled with the hydro-mechanical （HM） representation of the porous medium, are also examined. It is clearly demonstrated that, for the experimental conditions of the ventilation experiment （VE） that abstracted physical and empirical models of the tunnel, can be used successfully to represent the hydraulic behaviour of the tunnel and the hydraulic interaction between the tunnel and the surrounding rock mass.展开更多
The underground utility tunnel(UUT)is one of the typical urban underground structures,which usually requires mechanical ventilation systems for forced ventilation.In addition to the ventilation scheme for accident sce...The underground utility tunnel(UUT)is one of the typical urban underground structures,which usually requires mechanical ventilation systems for forced ventilation.In addition to the ventilation scheme for accident scenarios,the normal operating ventilation scheme deserves equal attention as it has a great impact on the air quality as well as the thermal and humidity environment inside the UUT.In this study,a UUT located in southern China is taken as the research object,and the effect of ventilation on its internal thermal and humidity distribution is explored with a combined use of field measurements and numerical simulations.The results of field measurements show that the average temperature inside the closed UUT is 20.5℃and the average humidity ratio is 14.1 g/kgdry;both are lower than those of the external environment.In the plum rain season,if the tunnel is ventilated without any treatment of the external airflows,surface condensation tends to occur near the air inlet while the region with high relative humidity would be distributed on both sides far from the air inlet.The study also discusses the effect of different temperatures and humidity ratios of the inflow air on the humidity inside the UUT,and on this basis,the humidity control strategy for UUT in the plum rain season is proposed.展开更多
基金Supported by Natural Science Fund ation for Major Research Plan of China (No.90815019)National Natural Science Foundation of China (No.50879053)National Key Project of Scientific and Technical Supporting Programs Funded by Ministry of Science and Technology of China (No.2006BAB04A13)
文摘Under forced ventilation,the dust diffusion of underground powerhouse construction is investigated using a 3D high Reynolds number k-ε model.The interfacial momentum transfers and the wall roughness in the wall function are considered.Ventilation in the third layer of underground powerhouse of Xiangjiaba hydropower station is used as a case.The geometric structure has a decisive effect on the airflow distribution.It is concluded that the dust concentration decreases gradually with the increase of the ventilation time.However,iso-concentration curves have the same tendency after 1 800 s.The dust concentration meets the ventilation and dust-prevention health standard after 2 300 s.The prediction by the present model is confirmed by the experimental measurement by Nakayama.
基金the context of the international DECOVALEX Project (DEmonstration of COupled models and their VALidation against EXperiments)EC project NF-PRO (Contract number FI6W-CT-2003-02389) under the coordination of ENRESA (Empresa Nacional de Residuos Radiactivos)
文摘At the Mont Terri Underground Research Laboratory （Switzerland）, a field-scale investigation has been conducted in order to investigate the hydro-mechanical and chemical perturbations induced in the argilla- ceous formation by forced ventilation through a tunnel. This experiment has been selected to be used for processing model development and validation in the international project DECOVALEX-2011. The con- ceptual and mathematical representation of the engineered void, which itself forms a major part of the experiment and is not simply a boundary condition, is the subject of this paper. A variety of approaches have been examined by the contributors to DECOVALEX and a summary of their findings is presented here. Two major aspects are discussed. Firstly, the approaches for the treatment of the surface condition at the porous media/tunnel interface are examined, with two equivalent but differing formulations successfully demonstrated. Secondly, approaches for representing the tunnel with associated air and water vapour movement, when coupled with the hydro-mechanical （HM） representation of the porous medium, are also examined. It is clearly demonstrated that, for the experimental conditions of the ventilation experiment （VE） that abstracted physical and empirical models of the tunnel, can be used successfully to represent the hydraulic behaviour of the tunnel and the hydraulic interaction between the tunnel and the surrounding rock mass.
基金supported by the Sponsored Shanghai Rising-Star Program,China(Grant No.20QB1404900)the National Natural Science Foundation of China(Grant No.52078380)+3 种基金the Ministry of Science and Technology of China(Grant No.SLDRCE19-B-14)the National Key Research and Development Program of China(Grant Nos.2017YFC0805000 and 2016YFC0802400)the Construction Program of Shanghai Engineering Research Center,China(Grant No.17DZ2251800)which are gratefully acknowledged.
文摘The underground utility tunnel(UUT)is one of the typical urban underground structures,which usually requires mechanical ventilation systems for forced ventilation.In addition to the ventilation scheme for accident scenarios,the normal operating ventilation scheme deserves equal attention as it has a great impact on the air quality as well as the thermal and humidity environment inside the UUT.In this study,a UUT located in southern China is taken as the research object,and the effect of ventilation on its internal thermal and humidity distribution is explored with a combined use of field measurements and numerical simulations.The results of field measurements show that the average temperature inside the closed UUT is 20.5℃and the average humidity ratio is 14.1 g/kgdry;both are lower than those of the external environment.In the plum rain season,if the tunnel is ventilated without any treatment of the external airflows,surface condensation tends to occur near the air inlet while the region with high relative humidity would be distributed on both sides far from the air inlet.The study also discusses the effect of different temperatures and humidity ratios of the inflow air on the humidity inside the UUT,and on this basis,the humidity control strategy for UUT in the plum rain season is proposed.
