Confinement of fire-induced smoke and carbon monoxide transportation by air curtain in channels

A Review of Ventilation and Environmental Control of Underground Spaces

Because of rapid urbanization, traffic problems, and other factors, underground spaces have been used more in the twenty-first century. Large underground spaces are required for underground city, metro, tunnel, mine, industrial and agricultural engineering, and civil air defense engineering. Underground spaces with varying thermal, ventilation, and lighting environments can face problems of comfort, health, and safety. High temperatures, high humidity, difficulty in flue gas emission, harmful microorganisms, radon, and physical and psychological problems are examples of issues. Air quality control technologies for underground spaces, such as ventilation, dehumidification, natural energy utilization, smoke extraction, and ventilation resistance reduction, are discussed. Ventilation for smoke-proofing/evacuation is also extensively addressed.

A catalyst powder-based spraying approach for rapid and efficient removal of fire-generated CO：From laboratory to pilot scale

In confined space fires, the large amount of CO generated by incomplete combustion of carbon-based materials poses a serious threat to the trapped people. However, the efficient method of removing CO in such disasters remains a great challenge. Herein, a spraying catalyst powder (SCP) approach is proposed for CO removal by oxidizing CO to harmless CO₂. Cu/Mn catalyst, synthesized by using ethylene glycol as solvent, was employed in this study. The influence of catalyst concentration, temperature, CO₂ concentration and initial CO concentration on CO removal performance of SCP approach was investigated. With 500 g/m³ catalyst, 25,000 ppm CO could be reduced to 2550 ppm within 1 min and completely removed in less than 2.83 min at 200 °C. The feasibility of SCP approach in practical application was validated by the remarkable CO removal performance for charcoal combustion in confined tunnel. SCP approach could effectively reduce the CO concentration, which would reach up to 12,659 ppm in the absence of SCP approach, to less than 1500 ppm within 30 min. The experiment results suggest that SCP technology can effectively remove the fire-generated CO and is promising for practical application in crowded occupancies, such as underground space and aircraft compartment.

Experimental study on fire smoke control using water mist curtain in channel

The hazards of the spread of fire smoke in a channel have been recognized. This paper relates to the potential use of a water mist curtain (WMC) for preventing the spread of fire smoke, focusing particularly on smoke control at the early stage of a fire, with the aim of reducing the harm of fire smoke and allowing time for people to escape. Fatal factors for occupant evacuation in a fire, such as carbon monoxide concentration, smoke temperature, and visibility, were measured in the section controlled by the WMC. The results indicate that the WMC can be effective in preventing fire smoke from spreading at the early stage, and may provide a useful reference for developing a novel method of smoke control. Furthermore, the effects of nozzles with different spray characteristics were investigated and an optimal working pressure was suggested. In addition, a mathematical model was simplified and used to analyze the interaction between the fire-induced smoke layer and WMC spray.