Diagnosis of damage to the ventilation system

Abstract

The article is devoted to solving of urgent problem to eliminate damages of two types in ventilation systems for air distribution efficiency increasing in the premises by swirled air flow, compact air jet, flat air stream and rectangular air jet. A mathematical model of air supply with swirled air flow, compact air jet, flat air jet and rectangular air stream in the room has been developed. It is shown that in order to achieve the maximum efficiency of air distribution it is necessary to ensure its supply by jets. Graphical and analytical dependences on the basis of the conducted experimental research are presented. Parameters of swirled air flow, compact air jet, flat air stream and rectangular air jet during the formation of a comfortable indoor climate are determined. The results of experimental studies of air supply to the room by the air distribution devices, which form a swirled air flow, compact air stream, flat air flow and rectangular air jet with adequate turbulence and long range of the supply air flow, are presented. It is established that with the increase of the angle of swirling plates inclination and ratio of the slit sides the air jets long range increases.

Diagnosis of three types damages to the ventilation system

“…If the velocity attenuation coefficient m is high, it indicates insufficient stream turbulence and a significant advantage of dynamic forces over friction ones. The velocity attenuation is directly related to air jet long range [31]. When the air jet long range becomes too high it needs to be reduced, because the conditions of comfort are violated [21].…”

“…When the air jet long range becomes too high it needs to be reduced, because the conditions of comfort are violated [21]. This phenomenon means that the ventilation system has a damage type 1 [31].…”

“…This is a round shape of air jet. Another suitable one is rectangular shape of air jet: a flat, compact or rectangular one [31].…”

“…There is opposite problem, connected with insufficient air velocity attenuation coefficient. As a result stagnant unventilated areas in the room are formed due to insufficient air jets long-range [31]. Air distribution devices have a high coefficient of aerodynamic resistance ζ and the ventilation system becomes energy consuming [18,22].…”

“…Air distribution devices have a high coefficient of aerodynamic resistance ζ and the ventilation system becomes energy consuming [18,22]. Thus, the air stream long range becomes too low and needs to be increased [31]. This results in to an excessive CO2 concentration in the premise [5,12].…”