Area balance method for calculation of air interchange in fire-resesistance testing laboratory for building products and constructions

• Main Authors: Sargsyan Samvel Volodyaevich, Spirin Aleksandr Dmitrievich
• Format: Article
• Language: English
• Published: Moscow State University of Civil Engineering (MGSU) 2014-09-01
• Series: Vestnik MGSU
• Subjects: control volume; air interchange; controlled environment; ventilation; mathematical model
• Online Access: http://vestnikmgsu.ru/files/archive/issues/2014/8/ru/13.pdf

Fire-resistance testing laboratory for building products and constructions is a production room with a substantial excess heat (over 23 W/m ). Significant sources of heat inside the aforementioned laboratory are firing furnace, designed to simulate high temperature effects on structures and products of various types in case of fire development. The excess heat production in the laboratory during the tests is due to firing furnaces. The laboratory room is considered as an object consisting of two control volumes (CV), in each of which there may be air intake and air removal, pollutant absorption or emission. In modeling air exchange conditions the following processes are being considered: the processes connected with air movement in the laboratory room: the jet stream in a confined space, distribution of air parameters, air motion and impurity diffusion in the ventilated room. General upward ventilation seems to be the most rational due to impossibility of using local exhaust ventilation. It is connected with the peculiarities of technological processes in the laboratory. Air jets spouted through large-perforated surface mounted at the height of 2 m from the floor level, "flood" the lower control volume, entrained by natural convective currents from heat sources upward and removed from the upper area. In order to take advantage of the proposed method of the required air exchange calculation, you must enter additional conditions, taking into account the provision of sanitary-hygienic characteristics of the current at the entrance of the service (work) area. Exhaust air containing pollutants (combustion products), is expelled into the atmosphere by vertical jet discharge. Dividing ventilated rooms into two control volumes allows describing the research process in a ventilated room more accurately and finding the air exchange in the lab room during the tests on a more reasonable basis, allowing to provide safe working conditions for the staff without the use of PPE.