01515282

Component

Newly built urban vehicular tunnels are generally geometrically complex with multiple pollutant discharge points, like exits of mainline and ramps and upper vents along the tunnel. The pollutant level must meet several air quality standards, such as maximum CO concentration inside the tunnel and NOx emission rates from discharge points. There's a need to incorporate multi-emission standards at when conducting ventilation controls. Therefore, this study focuses on the optimized quantitative control method that can deal with distributed discharge points and multiple emission targets for complex urban tunnels. The aerodynamic model and steady state pollutant dispersion model are established for such tunnel systems. According to the models, the air flow speed in one segment is mainly linearly affected by the numbers of running fans in the local and adjacent segments, with the linearization parameters influenced by traffic intensity. Emission standards at certain discharge points can be translated into nonlinear constraints for system inputs. Then an optimal pollutant discharge control method using nonlinear programming (NP) techniques is designed, which aims to meet multiple control constraints with minimal energy cost. The method is simulated for an urban tunnel in China. The results show that the proposed method can effectively keep the pollutant levels at corresponding emission targets under traffic variation in an energy efficient way. The special control sequences of fans deduced by the method are hard to get and the multiple emission targets are hard to fulfill simultaneously by heuristic approaches based on experience.

This paper was sponsored by TRB committee AFF60 Tunnels and Underground Structures. Alternate title: Nonlinear Programming Approach for Multipoint Pollutant Discharge Control in Urban Vehicular Tunnels

01503729

14-0442

English

18p

2014

Transportation Research Board 93rd Annual Meeting

Digital/other

Figures; References; Tables

Air quality management; Carbon monoxide; Flow; Nitrogen oxides; Nonlinear programming; Standards; Urban areas; Vehicular tunnels; Ventilation systems

Air flow

China

Bridges and other structures; Environment; Highways; Planning and Forecasting; I15: Environment; I72: Traffic and Transport Planning

Transportation Research Board Annual Meeting 2014 Paper #14-0442

TRIS, TRB, ATRI

Jan 27 2014 2:14PM