Optimal circulation ratio calculation method of open controllable circulation ventilation of extra-long highway tunnel

Abstract

The invention discloses an optimal circulation ratio calculation method of open controllable circulation ventilation of an extra-long highway tunnel. The method mainly includes: an energy-saving coefficient formula of the open controllable circulate ventilation system is determined, and then the first derivative and the second derivative of the cycle rate with respect to the energy saving coefficient are obtained according to the formula; according to the extreme value principle in higher mathematics, when the second derivative is less than 0 and the first derivative is equal to 0, the independent variable expression of the maximum value of dependent variable is obtained, and the optimal cycle ratio is obtained. Compared with a conventional ventilation system of air supply and exhaust shaft, the system of the invention has the advantages that the maximum energy saving of the open controllable circulating ventilation system can be obtained by using the circulating ratio, which is related to the equivalent coefficient of the frictional wind resistance coefficient of the circulating duct and the dust removal efficiency of the dust collector. The circulating ratio corresponding to themaximum energy saving coefficient of the dust removal efficiency and the equivalent coefficient of the dust collector can be calculated by using the formula.

Description

technical field [0001] The invention belongs to the technical field of disaster prevention and reduction in tunnels, and in particular relates to an optimal circulation ratio calculation method for open controllable circulation ventilation of extra-long highway tunnels. Background technique [0002] Highway tunnels are long and narrow spaces that are semi-submerged or shallowly buried. The treatment of pollutants such as smoke and dust generated by cars driving in tunnels has always been an important issue of concern to the industry. Generally, mechanical ventilation is used to dilute pollutants such as smoke and CO, and the dirty air is discharged to the environment outside the tunnel, and it belongs to the direct current system scheme. The ventilation system of long-distance or extra-long-distance road tunnels must cooperate with ventilation shafts to meet the wind demand for diluting pollutants in the tunnel. The ventilation of extra-long highway tunnels specifically inv...

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Problems solved by technology

However, problems such as the high cost of ventilation in super-long tunnels and the location of shaft excavation are restricted by geology and urban planning are still prominent, and the optimal cycle ratio calculation method for open-type controllable circulation ventilation in super-long highway tunnels has not yet been formed.

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