INTEGRAL AND DIFFERENCE FORMS OF REVISED CFK EQUATION FOR PREDICTION CARBON MONOXIDE THRESHOLDS IN TUNNELS

摘要

Carbon monoxide is one of the main target pollutants for ventilation in tunnels for it may do harm to human being under certain exposure. The original CFK equation(Coburn et al. 1965) can be calculated for CO concentration under circumstances that the CO concentration profile is uniform. This paper provides both integral and difference forms of revised CFK equations based on carbon monoxide concentration profile in longitudinal, transverse or semi-transverse ventilation tunnels. And CO concentration thresholds can be predicted by calculating under certain carboxyhemoglobyne(COHb) concentration by tools such as Maple or Matlab and etc.. Both the integral and difference forms of revised CFK equations have pros and cons. Although programming for difference form of revised CFK equations may be complicated, it is superior to integral form on feasibility and may not have to compromise too much on precision overall. But caution should be taken before calculation the difference form.