Study on Ventilation Chaos and Safety of Fire Smoke Exhaust System

火灾排烟系统通风混沌及安全研究

• 批准号: 13650653
• 负责人: NITTA Katsumichi
• 金额: $ 0.96万
• 依托单位: Kyoto Institute of Technology
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2001
• 资助国家: 日本
• 起止时间: 2001 至 2002
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-13650653/
• 关键词: Fire Smoke Venting System; Network Model; Ventilation Variety; Non-linear System; Chaos; CFD Analysis; Symmetric Ventilation; Stairwell; 換気ネットワークモデル; 壁体吸熱応答; 浮力換気; 換気回路網モデル; CFD

This survey related to the generation of variety modes in natural ventilation or fire smoke venting system and its effect on the indoor environmental comfortability or fire safety for refugee. The ventilation variety means the possibility of the generation of different ventilation modes such as ventilation rates, flow direction or room temperatures under same physical conditions for identical buildings. Regardless of deterministic physical system, the realization of a certain mode is stochastic process containing Chaos characteristics.In the study, it was shown that the usual buoyancy ventilation may potentially possess plural solutions or modes due to the non-linear system on condition that the ventilation in a building with multi rooms could be simulated with the (lumped constant closed circuits) network model. The ventilation variety was tested with the CFD analysis to verify that the variety is not particular in the network model but general in physical phenomena.The neglect of the ventilation variety would not bring the fire safety as the most important matter, and so the detection and counterplan for the unexpected and undesirable ventilation were surveyed using various building types, especially for the symmetrical buildings and multi-story houses with stairwells. From the simulation results, interesting knowledge was gotten that the ventilation for the symmetric building scarcely resulted in the symmetric ventilation modes. The smoke flow in the stairwell could be modeled with a set of simple orifice at each floor and the equivalent flow resistance was identified by the aid of CFD analysis.In conclusion, the network model for the multi-room ventilation calculation must have the great confidence of success as the technical method for ensuring against risks in fire smoke prediction, as far as the generation of ventilation variety is taken into consideration.

本研究探讨了自然通风或火灾排烟系统中各种模式的产生及其对难民室内环境舒适性或消防安全性的影响。通风多样性是指在相同的物理条件下，同一建筑物产生不同通风方式的可能性，如通风量、气流方向或室内温度。无论是确定性的物理系统，某一模式的实现都是具有混沌特性的随机过程，研究表明，在多房间建筑通风可以用（集总常数闭合回路）网络模型模拟的条件下，由于系统的非线性，通常的浮力通风可能具有多个解或模式。通过CFD分析验证了通风变化在网络模型中不是特殊的，而是普遍的物理现象，忽视通风变化不会带来消防安全的首要问题，因此针对不同建筑类型，探讨了通风异常和不良的检测和对策。特别适用于对称的建筑物和带有楼梯间的多层住宅。从模拟结果中，有趣的知识，对称建筑的通风几乎不会导致对称的通风模式。楼梯间内的烟气流动可以通过在每层设置一组简单的节流孔来模拟，并通过CFD分析来确定等效流阻，因此，考虑通风变化的产生，多房间通风计算的网络模型作为火灾烟气预测风险防范的技术手段，具有很大的成功把握。

项目成果

Nitta, Katsumichi: "Heat Response of Semi-infinite Walls in Transient Phenomena"Proc. 7th Int. Symp. on Building & Urban Environment Engineering. (in press). 8 (2003)

Nitta，Katsumichi：“瞬态现象中半无限壁的热响应”Proc。

Katsumichi NITTA: "Heat Response of Semi-infinite Walls in Transient Phenomena"Proc. 7th Int. Symp. on Building and Urban Environment Engineering. (in press). 8p (2003)

Katsumichi NITTA：“瞬态现象中半无限壁的热响应”Proc。

Katsumichi NITTA: "Modeling of the flow resistance of the stairwell on the ventilation network calculation, Proc. on 2nd Int. Building Physics Conference"Balkema Publishers (in press). 8p (2003)

Katsumichi NITTA：“通风网络计算中楼梯间流阻的建模，第二届国际建筑物理会议论文集”Balkema Publishers（正在出版）。

新田勝通: "多数室自然換気系におけるカオスと相似則"日本建築学会近畿支部研究報告集. 41号. 313-316 (2001)

新田胜道：《多房间自然通风系统中的混沌与相似律》日本建筑学会近畿分会研究报告第41. 313-316号（2001）。

Katsumichi NITTA: "Generation of Variety Modes in Building Ventilation"Study on Environmental Engineering (in Japanese). No.230. 17-28 (2001)

Katsumichi NITTA：“建筑通风多种模式的生成”环境工程研究（日语）。