Method of calculating reduction factor of fresh air quantity of air supply vertical shaft for tunnel opened circulatory ventilation

Abstract

The invention discloses a method of calculating a reduction factor of fresh air quantity of an air supply vertical shaft for tunnel opened circulatory ventilation. The method mainly includes: an equivalent fresh air quantity calculation formula for a circulatory flow that flows through a dust remover and is purified; in a controllable circulatory ventilating system, allowing quantity of fresh airinto the air supply vertical shaft to be equal to quantity of discharged polluted air from a discharge vertical shaft, and determining a calculation formula for equivalent quantity of fresh air sent by the air supply vertical shaft; in the controllable circulatory ventilating system, determining a calculation formula for equivalent quantity of fresh air discharged by the discharge vertical shaft;applying the three formulas above in the controllable circulatory ventilating system according to the conservation principle of physics so as to obtain a calculation formula of equivalent quantity offresh air for an ejector segment of a circulatory air duct; acquiring, from the calculation formula, a calculation formula for a reduction factor of fresh air quantity of the air supply vertical shaftin the controllable circulatory ventilating system. When the reduction factor of the fresh air quantity of the air supply vertical shaft in the open controllable circulatory ventilating system is less than 1, the controllable circulatory ventilating system can be executed to reduce actual air supply-discharge quantity.

Description

technical field [0001] The invention belongs to the technical field of tunnel disaster prevention and mitigation, and in particular relates to a method for calculating the fresh air volume reduction coefficient of an air supply shaft for open controllable circulation ventilation of an extra-long highway tunnel. 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 e...

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Problems solved by technology

However, the high cost of ventilation for extra-long tunnels and the location of shaft excavation are restricted by geology and urban planning are still prominent, and the calculation method for the reduction coefficient of fresh air volume in the air supply shaft for open-type controllable circulation ventilation of extra-long highway tunnels has not yet been formed.

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