Short-period forecasting algorithm for air pollution concentration in road tunnel with longitudinal ventilation

The computation of road tunnel air pollution model often adopted finite volume method, and was time-consuming, strenuous, difficult to be used in dynamical ventilation control system of road tunnel. Pollution concentration distribution in road tunnels was near linear along tunnel length. According to this characteristic, a new linear iteration formula was deduced from tunnel ventilation pollution model described by partial differential equation of second order. The practical methods to compute new variables in the formula were proposed. And the physical process denoted by the formula was illustrated. Then the formula was validated with detected CO concentrations from Qingling tunnel of Xihan highway, and it is found that the formula can cursorily offline forecast CO concentration in road tunnel outlets. To improve forecast precision, the previous formula was amended using detected data. And another predictive method with observation error correction was put forward and validated with the detected data. The results show this method can more accurately online forecast CO concentration in the tunnel outlets.