Research On The Emission And Propagation Characteristics Of Ambient Air Pollutants And Control Technology In Typical Underground Passage Space

Mine tunnels,traffic tunnels,underground air defense passages and urban underground corridors are all underground passages.The cross section of the underground passage space is usually tabular in shape,with a large aspect ratio of transverse direction to longitudinal direction,and with limited contact to the external environment.With the continuous development of industrial production and urban construction,the use of underground passages is increasing,and the environmental pollution of underground passage space has become increasingly prominent,which has become an urgent problem to be solved in health and environmental protection.The air pollutants in the underground passage space are mainly particulate pollutants and harmful gases.These air pollutants could exist in the underground passage space for a long time,which brings great harm to the safety of production and the health of personnel,especially the occupational diseases caused by long-term work in the underground passage space.In this thesis,the emission characteristics and control technology of ambient air pollutants,which are mainly particulate matter in underground passage space,are studied based on the typical tunnel as the object,combined with the mature research work and results of tunnel space.For the environmental pollution control in underground passage space,ventilation methods are adopted including induced ventilation,local air supply and roadway return air.The control and treatment of emitted pollutants is mainly manifested as a dilution effect,causing a considerable amount of pollutants to remain in the underground passage space for a long time.Therefore,it is necessary to study more effective control methods.In this study,field investigation and testing and numerical simulation were preformed to study and analyze the characteristics of particulate pollutants emitted by stationary sources of roadway mining surfaces,the characteristics of pollutants emitted from mobile sources of vehicles,and the propagation of pollutants in induced ventilation.The control technology was proposed and prediction method was put forward.The main research work and results of this paper are as follows:(1)The typical underground passage space ambient air pollutants were investigated and tested,the emission characteristics of ambient air pollutants in the underground passage space were studied and analyzed,the operation status of ventilation system in the typical underground passage space was tested and analyzed,and the pollutant emission and ventilation field control rules were analyzed and summarized.In this part,the characteristics of particulate pollutants emitted from fixed sources of roadway excavation surface in typical underground passage space were analyzed The propagation of pollutants in induced ventilation was measured,the particle size distribution and emission intensity of particulate pollutants were counted,the emission intensity and distribution rule of particulate matter and CO under traffic conditions were measured and calculated,and the problems of cumulative pollution and emission pollution in the whole area existed in the ventilation dilution control system were analyzed.(2)The theoretical model and numerical model required by the research on the emission and propagation characteristics of environmental air pollutants in typical underground passage space and the control technology are established and verified.For the fan and jet flow field of the underground passage involved in the tunnel ventilation field,experimental tests platform were established for the study of particulates and air flow field coupling.The experimental conditions were numerically calculated by orthogonal design,and the numerical calculation and the test results were verified by literature data.To study the problem of line source pollution caused by the passage of mechanical vehicles,a calculation model for the source-intensity emission of motor vehicles was established and verified based on measured data.This part provides the theoretical basis and the basis of model calculation method for the study of the emission and propagation characteristics of environmental air pollutants in typical underground passage space and the control technology,and provides the reference standard for the optimization and evaluation of ventilation purification and control system.(3)The characteristics and control technology of environmental air pollutant emission and propagation in typical underground passage space are studied and analyzed.In view of the environmental pollution control of underground passage space,the ventilation methods including induced ventilation,local air supply and roadway return air are mostly adopted.As a result,a considerable amount of pollutants still exist in underground passage space for a long time,resulting in the accumulation of pollution hazards and pollution emissions in the whole area.This study put forward the dry dust removal purification Partition risk control system,complementary ventilation duct conveying clean wind system and the technical measures,such as the environment outside low pollution emission for underground space environment air pollution control requirements in harmony with the control effect,underground space environment air pollution control is consistent with the external environment protection goal.An evaluation method based on human health was introduced to quantify the pollution and control problems of underground passage space construction and production operation.Percentage system was used to quantitatively evaluate the advantages and disadvantages of the design and operation conditions of local space and the whole ventilation and purification system,so as to provide indicators for the evaluation and comparison of ventilation and purification system.(4)The engineering applications of air pollutant control in typical underground passage space environment are analyzed,and the advantages of cleaning control in this study are compared with the dilution scheme of jet induced ventilation.Based on the practical engineering cases of typical underground passage spaces,excavation roadway,vehicle passage tunnel,and mine excavation tunnel,this paper analyzes the purification control effect of cleaning control measures and schemes for air pollutants in the underground passage space,and summarizes the research on the control of air pollutants in the typical underground passage space.