| Summary: | 碩士 === 國立雲林科技大學 === 環境與安全衛生工程系 === 106 === Taiwan is a densely populated island and its urban population is growing rapidly to result the phenomena of aggregated, high density, diversified and with complex equipment within the buildings. There are many. townhouses in the early days of Taiwan; however, the design of these buildings are out of date and their fire prevention plans are not complete with the evolution of times. Heavy casualty and property loss may happen once a fire broke out.
The most common type of townhouse is the long-type. This study collects the commonly seen long-type townhouse model and employs the open published Fire Dynamics Simulator (FDS) software to implement the fire simulation of the townhouse model. The extended burnings are discussed according to the following items: the burning status of the three-state fire, comparisons of different FDS versions, and differences analysis in different combustion modes. In addition, since the heat release rates of the three-state fire source are not the same, we employ a small model to observe the three-state fire source with same heat release rate. The results show that the extended burnings effect isn’t shown up by using the Material Reaction object. Instead, it is recommended to use the Surface Reaction setting to observe the extended burnings result. According to the results of flame distribution, temperature profile analysis and smoke flow concentration analysis of the gaseous fire source simulation, it shows that the temperature and the burning species in the early FDS 4 have the conditions of losing too fast inside a building. These drawbacks have been improved by the internal thermal insulation effect of the FDS 5. As for the solid-state fire source burning results, the temperature rising too fast and the burning species generated too low in the early FDS 5. By improving the characteristics of the species, all these have been controlled accordingly in the FDS 6 simulation results. The simulation result of liquid-state fire source combustion confirms that the liquid-state fire source in the early FDS 5 version is closer to the combustion result of the gas-state fire source, which can be proved by the combustion result and the computational speed ratio. By adding the combustion heat calculation of liquid evaporation in the FDS 6, its liquid-state combustion result is closer to the real one; however, the corresponding calculation speed is also slower than that of the solid- and gas-state. All three-state combustion results do not show much different while maintain at the same heat release rate. However, of the CO concentration in the FDS 5 is closer to the result of the real fire according to the calculation result.
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