THE EFFECTS OF VARIATION IN SHAPE OF SMOKE RESERVOIRS AND NUMBERS AND DISTRIBUTION OF SMOKE EXTRACTION POINTS ON THE TENABILITY WITHIN A COMPARTMENT

Abstract

This study has examined some important aspects of the engineered smoke control system, namely the shape of smoke reservoirs and the quantity and distribution of smoke extract points within a smoke compartment. Three different shapes of smoke reservoirs have been selected for analysis, namely square, rectangular, and T-shaped. The shape of the smoke reservoir has been varied, but the area, length and height have been kept identical. Four different configurations of extract points have been used in each shape of the reservoir: a single extract point located at the corner of the smoke reservoir, a single extract point located at the centre of the smoke reservoir, two extract points evenly distributed within the smoke reservoir and four extract points distributed within the reservoir. These configurations were implemented in three different shaped reservoirs: square, rectangular and T-shaped. The area, length and height of the reservoirs have been kept identical. In this work, the design parameters such as area and length of the reservoir, extract rate of smoke, replacement of air in the reservoir and other parameters have been stipulated from the Singapore Fire Code and Building Research Establishment Report. Fire Dynamics Simulator (FDS) model has been employed for this research, and results show that variations in the shape of smoke reservoirs or quantity and distribution of smoke extract points do have an effect on the tenability within the smoke compartment. Generally, it has been found that the untenable conditions within a square-shaped smoke reservoir increased at the slowest rate, given the fact that the smoke compartment is symmetrically shaped with equal dimensions on all four sides of the compartment. The smoke compartment with the most number of bends, i.e. the T-shaped smoke reservoir, has shown that the untenable conditions increase at the fastest rate, followed by the most elongated shaped smoke compartment (i.e. rectangular). For the other part of the research, results have shown that the provision of four extract points evenly distributed within the smoke reservoir resulted in the most favourably stable smoke layer and the untenable conditions within the smoke compartment increased at the slowest rate. However, one vent in the centre shows a better outcome than two evenly distributed points. It has been exhibited in this research that varying the shape of the smoke reservoirs, the quantity and/or the distribution of smoke extract points does affect its tenability within a smoke compartment. A sensitivity analysis has confirmed these findings.