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|Title:||Numerical simulation & analysis of sprinkler system in high-rise domestic building||Authors:||Woo, Yuen Kwong Wilson||Degree:||Ph.D.||Issue Date:||2020||Abstract:||For most of the domestic units in Hong Kong, they are located at the tall structures in dense urban zone. Every once in a while, some unintentional fire did happen and caused a few casualties and fatalities. Improvement/ enhancement on the local fire safety requirements for the domestic buildings may deem necessary and expedient. Given the fact that Hong Kong likes many other countries over the world, more than half of the fires occurred at the domestic premises. It is likewise legitimate for the circumstance in Hong Kong. As uncovered by the report from Hong Kong Fire Services Review (2014-2019), excluded from false alarm and unwanted alarm, about 80 percent of the fire was occurred at domestic buildings. It is not hard to presume that domestic portions have higher possibility of having lost and damage in case of fire. Prevention and mitigation measures ought to be forced to elevate the fire safety requirements now and again. In general, small domestic units of less than 30 m2 with an open kitchen are constructed in very tall residential buildings. Apart from open kitchen, glass partition is also common because of architectural design consideration. In case of fire, fire could be developed due to the mentioned features within a truly short period and the spread of fire would be another major issue should be addressed. Fire hazards in such tall residential buildings would be discussed in this study. Nevertheless, in many developed counties, sprinkler installation is as yet required to be provided at the domestic unit. Physical characteristics of domestic sprinkler under different pressures and flow rates studied earlier will be reported in this paper. Thermal sensitivity and the activation time of sprinkler heads were studied. The spray pattern of the sprinkler and resultant water density distribution will also be reported. Water characteristic tests studied are useful in determining their operating pressure and flow rate. Finally, small propanol pool fires were used in the fire test to find out whether the domestic sprinkler could be able to control the fire size. An experimental study was carried out which provided research information and data to assist in understanding the efficiency, effectiveness and benefit of automatic sprinkler protection system in domestic unit. By analyzing the temperature profiles, water consumption and relevant data, the efficiency, effectiveness and beneficial of using domestic sprinkler system in domestic unit in Hong Kong could be evaluated.
A fire chamber was constructed for the experiments. Two sets of experiments were designed with specified fire load density of 1,135 MJ/m2. The first set was burning of wood cribs with/ without sprinkler protection whilst the other set was burning of furniture with the same amount of fire load with / without sprinkler protection. Eventually, 4 fire experiments were conducted for analysis and comparison. Another focus of the study was the application of water curtain system for blockage of fire spread as it is widely used in fire protection of lives and properties in Hong Kong. By using the system, water is discharged in the form of a linear curtain for protection against internal or external exposure to fire spread; or as a fire separation barrier to segregate the fire side and the non-fire side. Many studies on the physics and chemistry of the water curtain in fire protection conducted by the researchers and scientists in the past both experimentally and academically, provide valuable results and findings. The relationship amongst the operating physical factors for the water curtain in radiation attenuation is investigated and general equations on their co-relation are established. By using the Computational Fluid Dynamics (CFD), the radiation intensity was identified accordingly. Radiation attenuation performance by water curtain system is defined by the radiation attenuation ratio when there is or there is no water curtain protection under different designed fire scenarios. Multiple regression analysis is adopted to estimate the coefficient and power factors of the variables in the derived formula. Data test is also conducted to verify the formula for the prediction of radiation attenuation by water curtain. The performance of water curtain in the attenuation of radiation from fire would be evaluated as well. With the aid of the wind tunnel, the standard plunge test has been conducted to evaluate the thermal response/ sensitivity of sprinkler heads. As the heat collector plates could reflect the radiation back to the sprinkler bulbs, theoretically, the sprinkler heads should be actuated in a shorter testing time. Thus, the performance of the domestic sprinkler with heat collect plate under the perforated/ baffle ceiling were studied consequently. Key aspects of the international standards and related fire safety codes for domestic buildings were reviewed. Measures to mitigate the concerned fire risks were also discussed.
|Subjects:||Dwellings -- Fires and fire prevention
Fire sprinklers -- China -- Hong Kong
Hong Kong Polytechnic University -- Dissertations
|Pages:||xxv, 70 pages, T-1 to T-17, F-1 to F-53, N-1 to N-22 : color illustrations|
|Appears in Collections:||Thesis|
View full-text via https://theses.lib.polyu.edu.hk/handle/200/10717
Citations as of Oct 1, 2023
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