Study Of Atmospheric Dispersion Model And Evaluation Of Environmental Economic Losses

The development of human society and economic growth need the support of energy. However, a great deal of requiring and consumption are causing serious environmental pollution, which has constrained the socio-economic development and welfare improvement. Environmental assessment of economic losses plays an important role in energy policy and environmental management. Atmospheric dispersion model is a key link between pollutant emissions from energy consumption model and economic losses evaluation. It is a method to achieve air quality prediction and economic losses.Five parts are included in this dissertation:a) Two-dimensional land-sea breeze circulation coupled random walk model; b) Two-dimensional diffusion model of street canyons; c) Three-dimensional dispersion model of street canyons, residential construction planning model and three dimensional land-sea breeze circulation model of the Dalian region; d) Environmental economic losses assessment model based on the atmospheric diffusion model; e) The prediction model of Environmental economic losses based on the energy-economic model. The objective of this study is to provide evidences for energy and environmental policy.(1) The land-sea breeze circulation model coupled with a particle trajectory model (Random-walk model) is developed by the analysis of the formation and the mechanism of the land-sea circulation physical model. Based on the data of the land-sea circulation in Dalian of China, the model simulates the diurnal variation of pressure, flow velocity, temperature and turbulent kinetic energy field, and also solves the pollutant concentrations in land-sea breeze. The air pollutant concentration in the background of land-sea circulation is also simulated by a Gaussian dispersion model, and the results reveal that the land-sea circulation model coupled with the random-walk model gives a reasonable description of air pollutant dispersion in coastal areas.(2) A pollutant dispersion model in urban street canyon is established by taking geometry of the building layout into account in order to predict the wall temperature, flow field and concentration field effects. Based on the impact of the inlet velocity and turbulence kinetic energy on the flow field, the Fluent-defined functions are used to improve the entrance boundary conditions. Compared with the experimental measurements and other turbulence models, the correctness of the model is validated and the modified RNG turbulence model showed a better prediction. Based on the model, the air pollutant (CO) concentration is calculated of the aspect ratio of five street canyons and the relative height of three buildings in architectural layout. The pollutants concentration distribution and pollutant retention value of different street layouts are compared. The impact on the air pollutant diffusion of street canyon layouts is analyzed. The proposals are also put forward to reduce air pollutants in urban street canyon.(3) Considering the temperature difference between street canyon wall and air, the non-isothermal street canyon model is established. The flow and pollutant concentration field are simulated. The model is validated by the wind tunnel experiments. Based on this model, the effects of six different temperature differences and the variable flow velocity on the street canyon flow field and concentration field was evaluated. The mechanism induced to the varieties of the street canyon flow field and concentration field is analyzed. The suggestions are proposed to improve air quality in street canyons and reduce the heat island effect and building energy consumption. It provides a theoretical and technical support for scientific and rational planning of the building layout.(4) Based on the theory and analysis of two-dimensional model, a plan of district model is established by taking the effects of different seasons and different architectural arrangements into account. It is used to simulate the pollutant concentration distribution of motor vehicles and fixed-point pollution sources. A suitable plan case is selected to help making a decision through the comparison of simulation results. Considering the specific geographical and industrial point source emission distribution of Dalian, a regional three-dimensional land-sea breeze circulation model is established. The PM10 concentration is simulated by this model. The effects of the height of the sea breeze circulation, velocity distribution, length and temperature inversion depth on pollutant concentration is analyzed. The proposals are put forward to defend the accumulation of pollutants in the land-sea breeze circulation. The simulation results provide a basic data for the evaluation of economic losses.(5) Using the PM10 concentration by the three dimensional land-sea breeze model and exposure-response relationship, the environmental economic losses assessment and prediction model is established. The economic losses due to air pollutant are estimated from the year of 2007 to 2010 of Dalian. The effects of future energy consumption and pollutant emission factors on the health of local residents are analyzed. The bearing capacity of the atmospheric environment and the implementation of the system effects of sewage charges are investigated. The policies are proposed to reduce environmental economic losses caused by air pollution, improve air quality and enhance public welfare.