Evaluation method for motor vehicle exhaust gas diffusion at structured intersection

Abstract

An evaluation method for motor vehicle exhaust gas diffusion at a structured intersection comprises the following steps of: 1, calculating the intensity of an emission source of a road segment line source according to parameters such as traffic flow of vehicles passing through a road segment, the proportions of various vehicle models and an emission factor; 2, converting idling emission of a queuing road segment into the intensity of a virtual line source according to parameters such as traffic flow arrival rate of the traffic flow queuing road segment, traffic signal green ratio, lane saturation flow rate, the proportions of various vehicle models and the emission factor and with reference to a CAL3QHC mode of an intersection exhaust gas diffusion mode; 3, building a coordinate system by taking an intersection center as an original point, and calculating corresponding concentration component values CA, CB, CC and CD of an arbitrary receiving point in an intersection region on a plane with a height value z in intersections A, B, C and D respectively, wherein CA is in the intersection A and is the pollutant concentration far away from the virtual line source 1 by L1; 4, calculating the pollutant concentration C of the receiving point according to the concentration of two segments of street canyons and a wind angle Theta in an upwind direction of the receiving point in the intersections; and 5, acquiring the pollutant concentration value C of the receiving point of which the concentration is within the period.

Description

technical field [0001] The invention relates to the technical field of environmental forecasting, in particular to an evaluation method for the diffusion of motor vehicle exhaust pollutants in the vicinity of a structured intersection with three sides being buildings and one side being a street park. Background technique [0002] Motor vehicle exhaust contains carbon monoxide, hydrocarbons, nitrogen oxides, particles and photochemical smog and other harmful pollutants, which is one of the main sources of urban air pollution. Road intersections are the most polluted areas of automobile exhaust emissions in the city. On the one hand, because urban intersections are the gathering and distributing intersections of traffic flows, traffic lights interrupt the smooth traffic flow and cause additional driving conditions such as acceleration and deceleration. Vehicles often stop and wait at intersections, resulting in idling, which emits more exhaust pollutants than ordinary roads; ...

AI Technical Summary

Problems solved by technology

There are buildings and open spaces around this structured intersection, and the exhaust emission and diffusion of traffic flow are more complicated than those of ordinary intersections.

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