Experimental Study on Gas Temperature During Fire in a Compartment with a Sloped Roof Vent

Twenty-two experiments have been conducted, with six different sloped roof vent areas, three fire source areas, and five door sizes, in a model-scale compartment with geometric dimensions of 150 cm length by 80 cm width by 150 cm height, to explore fire growth behavior and the temperature distribution in a compartment with a sloped roof vent (natural ventilation). It has been found in the experiments that, with increase of the sloped roof vent area, the maximum mass burning rate decreases gradually and the total combustion duration increases, in the condition of equal weight of total fuel in each test. This phenomenon demonstrates that the influence of the weakening effect owing to more energy loss via the roof vent is stronger than the strengthening effect due to combustion acceleration by enlarging the roof vent area, in the current experimental configuration. Moreover, the relationships between the average gas temperature rise and the roof vent area, as well as between the average gas temperature rise and the ratio of the roof vent area to total vent area, in the steady fire stage are summarized and quantified. In addition, it is found that, even when the roof vent area reaches 6.7 % of the floor area, the smoke layer height descends quickly, which poses a challenge to human evacuation.