Characteristics Of Pool Fires Research Articles

Study of Baffle Height and Wind Velocity Effect on the Characteristics of Pool Fires in a Wind Tunnel

Wind-blown pool fire accidents in a ventilated tunnel usually pose and present serious risks to properties and personal safety. In this paper, the flame characteristics and flow field changes of pool fires under the combined influence of baffles and crosswinds were investigated using wind tunnel experiments and numerical simulations. The fire experiments reveal that the flame length increases first, then decreases with increasing crosswind speeds up to 3 m/s and then becomes almost constant. Finally, as the wind speed continues to increase, the flame length remains constant. The flame height decreases with crosswind speed up to 3 m/s and then remains almost unchanged. As for the flame tilt angle, the flame above the baffle increases first and then remains unchanged when the velocity of crosswind increases from 2 to 5 m/s. According to the simulation results, the clockwise rotating eddy will be generated downstream of the baffle. The recirculation zone on the surface of the pool transfers the fresh air to the flame. The vortex zone downstream of the pool can retain heat and send back unignited fuel vapor to be burned rather than being blown away. The results may provide beneficial suggestions for understanding flame development behind obstacles for ventilated tunnels.

Fire Risk Assessment and Experimental Study of Transformer Insulating Oil

Most previous works concentrated on burning characteristics of pool fire using common fuels such as heptane, propane, biodiesel, and diesel, whereas burning characteristics for transformer oil are barely involved, although transformer oil is arguable of more practical importance in power system. This study performed a series of pool fire experiments using transformer oil to study the burning characteristics in open and confined spaces. Three fuel thicknesses and five initial temperatures are changed in open space. The essential parameters of mass loss rate, flame height, and fire plume temperature are obtained and analyzed. Moreover, three oil pool diameters are varied in a chamber. The main conclusions are summarized as follows: the variations of mass loss rate, flame height, and fire plume temperature not only obviously increase as the fuel thickness increases from 0.5 cm to 1.0 cm, but also insignificantly increase as the fuel thickness changes from 1.0 cm to 2.0 cm. The mass loss rate is less sensitive to the initial temperature of transformer oil, but the flame height and fire plume temperature significantly rise with the initial temperature. Moreover, the modified models to predict the flame height and fire plume temperature for 25°C initial temperature conditions are proposed, but the fitting coefficients are obviously different from that for common liquid fuels. The flame height in confined space is higher and will rapidly increase to the maximum, then decreases, and tends to be stable, which is obviously different from the oil pool fire burning in open space. In addition, the phenomenon of burning blast and the ignition of the adjacent oil pool will be observed with a high‐temperature ignition source and a certain high temperature in a chamber under 30 cm oil pool diameter, which will not be recorded in 15 cm and 20 cm.

Efficient water deluge nozzles arrangement on offshore installations for the suppression of pool fires

Offshore installations that handle hydrocarbons are in serious danger of fires and/or explosions. Pool fires are a significant risk related to major fire accidents, and active protection systems such as water deluge systems are used to reduce the consequences of high temperature and radiation resulting from pool fires. Thus, it is important to decide on the locations of water deluge nozzles for effective fire suppression, and the aim of this study is to introduce an efficient methodology for selecting the locations of water deluge nozzles. The locations of water deluge nozzles are selected using a proposed water deluge location index based on the characteristics of pool fires. The methodology is based on probabilistic approaches associated with credible scenarios representing possible events on offshore topside structures. This methodology, applied to examples, is used to determine the efficient arrangement of water deluge nozzles on a hypothetical FLNG topside structure. The effectiveness of the new methodology is verified through comparison with uniformly distributed nozzles using a computational fluid dynamics simulation.

Pool Fires Of Biofuels And Their Blends With Petroleum Diesel

The combustion characteristics of pool fires of biofuels, canola methyl ester (CME), soy methyl ester (SME), and their blends with a petroleum fuel (No. 2 diesel) were studied. The fuels were burned in cups of two sizes (0.042 m and 0.057 m in diameter and 0.038 m height) that simulated convection-dominated small pool fires of liquids. Blends of CME and SME with diesel fuel were tested with biofuel concentrations of 25, 50, and 75% by volume. The mass burn rate, the fuel surface regression rate, the radiation emission from the flames, the flame temperature field, and the emission indices of CO and NOx were recorded. The fuel surface regression rate in both containers was comparable. Both the fuel mass burning rate and surface regression rate varied non-monotonically with the volume concentration of biofuel in the blend. The radiation fraction of heat release and the temperature profiles were similar for all the flames. The CO emission index decreased with the biofuel content in the fuel. The NOx emission index did not show a systematic and significant dependence on the fuel blend; however, it was smaller than that measured in the turbulent gas jet and liquid spray flames of the corresponding fuels.