Chen Y.,Chinese Peoples Armed Police forces Academy |
Shu Z.-J.,Chinese Peoples Armed Police forces Academy |
Li S.-C.,Chinese Peoples Armed Police forces Academy |
Ji J.,State Key Laboratory of Fire Science
Procedia Engineering | Year: 2011
Mechanical air supply method is the most common smoke proof method that be used in stairwell to control the spread of smoke. The determination of the amount of mechanical air supply is a difficult problem in engineering design of mechanical smoke control. Comparison and analysis on the smoke control volume flow rate of the actual project were performed in this paper, and then CFD simulation was performed with different smoke control volume flow rate. Results show that the mechanical smoke control volume flow rate provided by either codes provision or calculation method has value range, thus uncertainty is brought into the determination of smoke control volume flow rate. In actual engineering design, appropriate smoke control volume flow rate can be obtained through numerical simulation on the basis of formula calculation and code provision. © 2011 Published by Elsevier Ltd.
Liu S.,Hefei University of Technology |
Zhang Y.,State Key Laboratory of Fire Science |
Gu Q.,Hefei University of Technology
Chinese Journal of Sensors and Actuators | Year: 2010
Multiparameter fire detection nodes based on Wireless sensor network is designed, which can detect temperature , humidity and smoke concentration. The distorted fire rate is decreased with multiparameter coincidence technique. And a shortest path routing algorithm is proposed according to multi-hop transceiver based on CSMA/CA principle ; the sensor nodes can connect each other automatically, the sensor data can be transmitted within minimum hops. Using this type nodes, a real-time fire monitoring system is built up. As the experiment result ; the maximum distance of single hop transmission is 100m, the delay time of every hop within multi-hop communications is about 50ms, the sensitivity of fire smoke reaches the first class level, the parameter of humidity is used to eliminate the distorted effect of water vapor.
Wang C.,State Key Laboratory of Fire Science |
Guo J.,State Key Laboratory of Fire Science
Procedia Engineering | Year: 2011
Jet fire is one of the most frequent fire accidents occurring due to leakage in storage and transportation process of combustible gas and liquids. For fire safety consideration, computer simulation was performed on liquid jet fire with various injection conditions, based on LES and mixture-fraction combustion model. In liquid jet fire simulation, it is suggested that D */δx reach 18 or more. With increasing, the fire length and lift-off height decreases as injection angle increases. Maximum centerline temperature is not dependent on injection angle. Large injection pressure causes the fire length and lift-off height to rise, and also leads maximum centerline temperature to drop slightly. Various nozzle heights above the ground have little influence on jet fire. © 2011 Published by Elsevier Ltd.
Xie Q.,State Key Laboratory of Fire Science |
Zhang H.,State Key Laboratory of Fire Science |
Tong L.,State Key Laboratory of Fire Science
Journal of Hazardous Materials | Year: 2010
The objective of the present study is to analyze the fire protection properties of old and new cables through TG, FTIR and MCC experiments. The results show that the mass loss of old cable sheath is clearly larger than the new one when the temperature is higher than 550. K in air or nitrogen atmosphere. It suggests that the old cable sheath starts to pyrolyze generally at the same temperature based on the analysis of the onset temperatures of mass loss. The results also show that there is a main peak DTG for the old and new cable sheath under each condition. However, the main peak DTG of old cable sheath is larger than that of the new cable sheath, especially in air atmosphere. The FTIR experiments show that the HCl is released by the new cable later but more quickly than the old cable. The MCC experiments suggest that compared with the new one, the peak heat release rate is larger for the old cable. It illustrates that the old cable sheath generally pyrolyzes and combusts more strongly and completely than the new one. Namely, the fire protection properties of the old cable in old buildings are relatively weak. © 2010 Elsevier B.V.
Zhang T.,State Key Laboratory of Fire Science |
Yang L.,State Key Laboratory of Fire Science |
Chen Y.,State Key Laboratory of Fire Science
Proceedings of the 9th Asia-Pacific Conference on Combustion, ASPACC 2013 | Year: 2013
In order to investigate the combustion characteristics of solar cell under different radiation heat fluxes, a series of experiments were conducted, in which the HRR and mass loss were measured; the heat flux of which varied from 30 to 40kW/m2 in a step of 10kW/m2 and the solar cell was ignited by the electrical spark. The HRR of the solar cell are 800-960 kW/m 2 in the radiation intensity of 30-40 kW/m2. The mass loss under the two heat flux ranges between 100-87%. The radiation intensity and the solar cell itself thermophysical properties determine the HRR and total mass loss in the combustion process. The change of CO concentration and HRR in various radiation intensities is very similar.