Zazymko V. Improvement of the method for determining total air leak through sealed fire area

The thesis is devoted to improvement of the method for determining total air leak through sealed fire areas (SFA) of various extent at coal mines adjusted for transient aerodynamic processes occurring at SFA during air leak measurement. Transient process regulations at SFA have been given theoretical treatment with due consideration for aerodynamic parameters of the area (pressure, pressure drop, natural draught). Transient process mathematical model as well as the mathematical model discrete counterpart have been developed enabling to predict pressure field dynamics and air rate at SFA after the area is unsealed. Statistical relationship has been obtained for transient process duration, which includes gob volumes, pressure drop across intake air stopping and open pipe air resistance. It has been established that in a real-life situation the duration of a transient aerodynamic process can be as long as several hours. Measuring pipe parameters (diameter, length, resistance) with due allowance for such factors as conventional equipment measuring uncertainty, gas-content-based category of a mine, safety of a measuring operator, have been well justified. Basic results obtained have been used for further development of the method for determining total air leak through sealed fire areas, which encloses recommendations about stopping erection, preparation for calculating transient process duration and air leaks, direct measurement of pressure drop and air velocity in the measuring pipe of an intake air stopping. Key words: fire areas, sealing, stopping, air leaks, transient aerodynamic process, mathematic modeling, pressure drop, resistance, measuring pipe, length, diameter, method.