Inverse Identification Of Outdoor Pollutant Sources In Industrial Park Based On Adjoint Probability Method

In industrial parks,there are often enterprises that do not meet exhaust emission requirements,and toxic gas leakage occurs from time to time.These phenomena endanger the health of the human body and the environment,and have aroused strong attention of the state.At present,the industrial gas pollution control methods have been upgraded from the overall management,which mainly readjusts the industrial structure and energy structure,to the precise management.Due to the suddenness and complexity of exhaust gas pollution in industrial parks,the actual application effect of source list method and grid method is not satisfactory,and he control of gas pollution in industrial parks is still a problem.Probability based adjoint method has shown the feasibility of locating multiple outdoor contaminant sources in constant wind field and shows superiority compared to traditional trial and error method.However,in actual situation,the outdoor wind field changes momentarily which results in the unsteady of flow field and concentration field.The change of wind,especially the change of wind direction,can be the decisive factor in source identification.This paper proposes an advanced adjoint probability method to track pollutant sources in dynamic flow field and develops a source identification strategy with limited information detected by a pollutant monitoring vehicle.The practicability of this strategy is discussed and verified in simulations and wind tunnel experiments.This paper mainly includes the following research contents:(1)The algorithm of the adjoint probability method used in the dynamic flow field is proposed,including the simulation method of dynamic boundary conditions and the selection principle of measuring points.An open space field of 2 km × 2 km is conducted to illustrate and validate the developed method.In two cases with a single source and multiple sources of pollution,forward dynamic simulation result of weather conditions is considered "real data" contaminant concentration.The developed algorithm and process promptly and accurately identify the source locations in both cases.(2)In a two-dimensional open space field,The effects of wind simplification,turbulent diffusion coefficient,concentration tolerance and wind stability on positioning accuracy are discussed.An optimal simplified method of unsteady wind field and the recommended values of calculation parameters are proposed.When the parameters are appropriate,the positioning accuracy(the ratio of distance error to the diameter of the affected range)of this method can reach less than 10%.(3)In a three-dimensional detailed model of the actual industrial park,forward dynamic simulation result of weather conditions is considered "real data" contaminant concentration.The measurement and source-finding process using a pollutant monitoring vehicle is explained to prove the feasibility of applying this method in a real park.(4)The wind tunnel experiment of a certain building group model is carried out,the forward simulation results are compared with the experimental data to verify the accuracy of the simulation.Experimental data is used in source location to verify this strategy.In addition,the use of only one fixed monitoring station’s records in different time periods for single source tracing is discussed and verified,which extends the application scenarios of this method.