Method and device for controlling ventilation amount with respect to sealed pipe

Abstract

The present disclosure relates to a method of controlling a ventilatory volume for inhibiting a release of a harmful gas such as an offensive odor or a toxic substance from a closed-type duct. The method of controlling a ventilatory volume is characterized in that (i) the closed-type duct is divided into a single main duct and multiple branch ducts in a planned area and depends on a harmful gas prevention closed-type duct model in which a negative pressure may be formed by a separately provided means for forcedly discharging gas, (ii) in a state in which no forced gas discharge from the closed-type duct is made, the harmful gas is determined as a standard flow velocity by comparing inverse velocity values of natural positive-pressure flow velocities according to a difference in temperature, a difference in concentration, a difference in elevation of the duct, a stack effect, and the like, (iii) the standard flow velocity is assigned in a lump to flow velocities in the single main duct and the multiple branch ducts provided in the closed-type duct, a sum of the flow rate in the main duct and the flow rate in the multiple branch ducts is basically determined as a ventilatory volume by the means for forcedly discharging gas, and particularly, only the flow rates in the branch duct at the junction points are corrected and determined in a lump based on a ratio of a pressure loss in the main duct to a pressure loss in the branch duct. The method of controlling a ventilatory volume may be applied to the closed-type duct having various usages and shapes and may provide a quantitative criterion related to a minimum ventilatory volume required to inhibit a release of a harmful gas, thereby reducing costs, maximizing operational efficiency, and an operational criterion practical to various types of ventilation devices.