Study on fire-rescue command system and key technology of ultra high-rise building
Ultra high-rise buildings always regarded as a landmark of a city. But it also brings some fire safety problems due to crowded people, long evacuation distance, fast fire spread, etc. So the fire consequences are very serious, and it is also difficult to search the personnel in the building under emergency, which make the fire-rescue action of the ultra high-rise building very difficult. As a result, a set of effective information collection and analysis method are needed, which includes the collection of trapped personnel location information, fire information, evacuation routine, similar fire case in history and so on. There has not been a mature ultra high-rise building fire rescue system worldwide so far. In the study, we focused on several key technologies related to this problem, including indoor personnel locating, multisensory fire information fusion, fire source identification and so on. Based on the above technologies, the framework and functional design of an ultra high-rise building fire command and rescue system has been developed.
Experimental Studies of Electromagnetic Wave Attenuation by Flame and Smoke in Structure Fire
Attenuation of electromagnetic waves in the fire scene is an important issue when the stability of wireless communication is concerned, especially in fire rescue scenarios of high-rise buildings. Therefore, it is of importance to study the effects of flame and smoke on the attenuation of electromagnetic waves in structure fire. In this article, the influence of flame was studied through using alcohol as fuel. Different types of fuels were used to produce different concentrations of smoke. Different ranges of electromagnetic wave frequency from 350 MHz to 400 MHz were also used to investigate the frequency-dependent properties of the attenuation effect. The results show that flame itself does not have significant effects on the electromagnetic wave attenuation, but smoke plays an important role. Smoke from diesel fuel results in larger signal attenuation than other fuels, with attenuation of 1.16 dB at 300 MHz. The relationship between the concentration of smoke and signal attenuation follows the first-order exponential function. It also indicates that electromagnetic wave attenuation is frequency-dependent. The attenuation is 5.43 dB at 360 MHz when the smoke concentration is 20 dB/m, but only 0.26 dB at 400 MHz. It is suggested that a frequency-dependent assessment should be considered for investigating the reliability of the wireless communication system in structure fire in high-rise buildings.
Design Of Neural Net To Detect Early Stage Of Fire And Evaluation By Using Real Sensors' Data
Sensitive fire sensors are necessary to detect fires in their early stage, but they often produce false alarms from non-fire phenomena. It has lately became clear that fire and non-fire patterns exist as a result of analyzing fire and non-fire testing data. Changing the rate of sensor output per minute and normalized sensor output are used as patterns for analyzing sensors' data in various condition. An odor sensor and a smoke sensor are very effective in discriminating between fire / non-fire phenomena by adopting artificial neural net which has been trained to recognize their patterns.