Mechanical Smoke Exhaust for Small Retail Shop Fires

Abstract

The performance of mechanical smoke exhaust systems in a small retail shop fire will be evaluated. A series of full-scale burning tests will be carried out and the results will be justified by numerical experiments. A zone model has been developed to predict the fire growth in small retail shops with different equations on axisymmetric fire plume entrainment and spill plume. In addition to verifying the developed model, the results will also be compared with those predicted by another zone model CFAST (version 5.01) and a field or computational fluid dynamics model Fire Dynamics Simulator FDS code (version 3). The correlation between the mechanical exhaust rate and plume entrainment rate for keeping the smoke layer interface at a certain height under a steady burning fire will be analyzed. Further, the application of different plume correlations will be investigated. The effectiveness of mechanical exhaust in retail shop fires will be discussed and some factors affecting the system performance will be analyzed.

Investigation on mechanical exhaust of cabin fire in large-space building

“…According to the performance-based design, the volume rate of subsidiary exhaust system in cabin can be calculated by eqs. (5) and (6). Take the hall and cabin in the simulation as the example and keep air change rate of the large space at 6 ACH according to the code.…”

“…Fires commonly occurring in a large-space building include the free fire and the enclosure fire such as the inside cabin fire. A great deal of experimental studies [2][3][4][5][6] have been done on mechanical exhaust under free-burning fire in large space buildings. However, there has been few full-scale experimental studies on cabin fire inside the large space [7] and the resultant smoke descending, especially on smoke exhaust efficiency of operating fans in large spaces in the case of such cabin fire, which need to be studied through full-scale experiments.…”

Ventilation effect on fire smoke transport in a townhouse building

“…He et al at the CESARE's Experimental Building-Fire Facility (EBFF) conducted an experiment consisting of a four-story full-scale building [2], presenting the natural ventilation effect for fire and smoke movement. Other researches, such as smoke control for underground car parks [3], the small retail shop [4], and the atria [5,6] have also emphasized that vent sizes and ventilation positions impact fire and smoke movement in the fire building.…”

The Analysis of the Natural Smoke Filling Times in an Atrium

“…It should be noted that in McCaffrey correlation equations, plume properties are assumed to be independent of fuel and only dependent on heat release rateQ [9]. The correction of the smoke plume region is given bẏ…”

“…Many of them are widely applied to the zone model. For example, CFAST [8] computer simulation software used two-layer zone model (upper hot layer and lower cold layer) and McCaffrey's correction to calculate the plume entrainment rate [9]. However, different entrainment rates were obtained under same fire source because some equations were obtained by theoretical research and others by experimental results.…”