高层住宅厨房集中排烟气道系统导流构件实验与模拟研究

发布时间：2018-08-11 18:41

【摘要】：近年来，随着人口城镇化的发展趋势，多层、高层建筑将逐渐成为今后城市住宅的主要趋势。但是随着大规模高层建筑的建造，往日多层住宅厨房排烟问题的隐患，就在高层建筑中显现出来。厨房作为家居环境中最大的污染物发生地，时刻危害着室内人员的健康。为了不污染室内环境，保障居住人员的身体健康，快速有效地排除室内受污染的空气是室内通风设计中的重中之重。本文通过对集中排烟气道的排烟状况进行了现场实测，并对导致厨房排烟困难、住户厨房间串烟、串味等热点问题进行了总结，最后通过CFD数值模拟方法对一些排烟问题做了进一步深入研究。首先，分别对两种不同类型D*-型、E*-型33层等截面集中排烟气道的排烟情况进行了测试。对比分析了系统在不同吸油烟机开启率下，各层排烟道支管、主管的速度值与静压值。在相同测试条件下，对比各层用户的排风量发现，E*-型等截面变压式33集中排烟道排烟情况很不理想，，面排烟道系统排烟情况较好，在专家推荐的吸油烟机开启率下，各层用户基本能各层用户的排烟量很难达到设计要求，且各层用户排烟量也不均匀。D*-型等截基本满足排烟需求。总结原因，E*-型排烟气道截面尺寸偏小，系统内部构件局部阻力偏大。建议增大系统主烟道截面尺寸，并对局部构件进行优化。此外，本文还对安装屋顶动力风帽的排烟系统的排烟情况进行了测试，与未安装屋顶动力风帽工况对比发现，在系统出口安装初始全压小的动力风帽，并不会提高系统的排烟量，相反当系统开机率较大时，由于动力风帽自身阻力偏大，反而阻碍了系统排烟。通过对以上两种排烟气道排烟的实测发现，吸油烟机初始压头有限，要想提高系统排烟能力，必须降低烟道内气体在流动过程中所受的阻力。笔者利用CFD技术对几种常见的烟道内部导流构件进行了数值模拟，得出了各导流构件的局部合流阻力系数；分析在主、支管道不同面积比、不同流量比下导流构件局部合流阻力的变化规律，并对导流构件的性能及防串烟能力进行了评价。最后本文还通过数值模拟技术，分析了烟气的热压作用对系统排烟能力的影响。本文根据不同室外温度的变化设置了多个工况，模拟了不同室外温度下系统各层用户的排烟量，并与不考虑温度的工况进行对比。结果发现，当模拟条件设置相同时，随着室外温度的降低，排烟气道系统排烟能力相应的逐渐增大。尤其对于底部用户，受热压作用更加明显。但当排烟温度与室外空气温差值不大时，其热压作用并不明显。因此，在住宅厨房集中排烟道设计中，可以将烟气的热压作用当做其中的安全因素，忽略其对系统排烟的影响。
[Abstract]:In recent years, with the development of population urbanization, multi-storey, high-rise buildings will gradually become the main trend of urban housing in the future. However, with the construction of large-scale high-rise buildings, the hidden trouble of smoke exhaust in the past multi-storey residential kitchens appears in the high-rise buildings. Kitchen as the largest pollution in the home environment, always endangering the health of indoor personnel. In order not to pollute the indoor environment and to ensure the health of the occupants, it is the most important in the indoor ventilation design to remove the indoor polluted air quickly and effectively. In this paper, the field measurement of the smoke exhaust condition of the centralized exhaust pipe is carried out, and the hot problems, such as the difficulty of exhaust smoke in the kitchen, the series of smoke in the household kitchen, the string taste, and so on, are summarized. Finally, some problems of exhaust smoke are further studied by CFD numerical simulation method. First of all, the exhaust smoke of two different types of D- EN-EN-33-layer constant-section concentrated exhaust ports were tested. The velocity value and static pressure value of each layer exhaust flue branch pipe are compared and analyzed under the different smoke absorber opening rate of the system. Under the same test conditions, by comparing the exhaust air volume of different layers of users, it is found that the situation of exhaust smoke is not ideal in the 33 centralized flue of the Ela-type constant cross-section variable pressure type, and the smoke exhaust condition of the surface exhaust flue system is better. Under the open rate of the smoke absorber recommended by the experts, It is difficult to meet the design requirements for the amount of smoke discharged by the users of each layer, and the amount of smoke discharged by the users in each layer is not even. Da-type basically meets the needs of the exhaust smoke. The reason is that the cross section size of E- type exhaust duct is small and the local resistance of the internal components of the system is too large. It is suggested that the section size of the main flue should be increased and the local components should be optimized. In addition, the exhaust smoke of the exhaust system installed with the roof power hood is tested. Compared with the working condition of the uninstalled roof power hood, it is found that the initial full pressure small power hood is installed at the outlet of the system. On the contrary, when the system boot rate is high, the system exhaust smoke is hindered because of the larger resistance of the power hood itself. It is found that the initial pressure head of the smoke absorber is limited and the resistance of the gas in the flue must be reduced in order to improve the exhaust capacity of the system. By using CFD technique, several common internal diversion components of flue are numerically simulated, and the local confluence resistance coefficient of each diversion member is obtained, and the ratio of different areas of main and branch pipes is analyzed. The variation law of local combined flow resistance of diversion component under different flow ratio is studied. The performance of diversion member and its ability to prevent smoke are evaluated. Finally, the influence of hot pressure on the exhaust capacity of the system is analyzed by numerical simulation technology. In this paper, according to the change of different outdoor temperature, several working conditions are set up, and the smoke output of different layers of the system is simulated under different outdoor temperature, and compared with the condition without considering the temperature. The results show that with the decrease of outdoor temperature, the smoke exhaust capacity of exhaust port system increases gradually when the simulation conditions are the same. Especially for the bottom of the user, by the role of more obvious hot pressing. However, when the difference between smoke exhaust temperature and outdoor air temperature is small, the effect of hot pressing is not obvious. Therefore, in the design of centralized exhaust flue in residential kitchen, the hot pressing of flue gas can be regarded as the safety factor, and the influence on the exhaust smoke of the system can be ignored.
【学位授予单位】：西安建筑科技大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU241.8;TU976.9

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