建築物正負壓區劃性能式 煙控設計之實測與模擬研究

Field Test and Computer Modeling of Zone Pressurization for Performance Based Smoke Control

張家豪(Cha-How Chang)

指導教授 ： 蔡尤溪

國立臺北科技大學/機電學院/能源與冷凍空調工程系碩士班/碩士(2011年)

摘要

本研究利用正負壓控制作為防煙區劃，防止火場煙流入相對正壓之非火災區，並探討維持火災區域控制為負壓、另非火災區域則為正壓之無害環境。本研究將建築物平面分為多個防煙區劃，運用送排風造成各區劃不同之相對正負壓差，進一步探討各防煙區劃氣流與風量控制等相關設計研究。透過案例實測與電腦軟體模擬結果進行比對驗證，證明加壓設備建立空間正壓可防止煙霧進入，有利於火災時避難逃生。
本研究考量各項參數如：牆面及樓版隔間材質孔隙率、門窗材質孔隙率及各項設備送排氣等數值，並使用美國NIST 發展CONTAM軟體進行多區域氣流氣壓進行分析，建立建築物內外部氣流滲透、不同區域氣流狀態、外部風壓及溫度之各種參考條件，分析正負壓區劃氣流壓差數值。
在實測方面以一辦公大樓建築物進行實際驗證，並利用建築物十九樓進行本研究之正負壓區劃實驗，針對各區劃相對壓差、風速、溫度及追踪氣體濃度，進行模式量測，以SF6為示蹤氣體模擬煙流，量測紀錄氣體的擴散濃度及各區壓差數值，實測結果印證建議之正負壓區劃防煙規範之可行性。
模擬結果與實測值進行比對分析後發現與模擬數值相當接近，且由模擬可知當室內辦公室發生火災時，逃生路徑動線上之相對壓力值，符合實際量測之壓力值且各區之SF6示蹤氣體濃度皆為背景值，觀察得氣體沒有向上下樓層擴散，有利人員避難逃生。

關鍵字

正負壓區劃 ； 建築防煙 ； 性能式設計 ； 空調送風 ； CONTAM

並列摘要

In this study pressure control is investigated as a mean of smoke zones, so to prevent the fire smoke flowing into the non-fire areas that are maintained at relative higher pressure. Smoke exhaust is a mean to cause relative negative pressure in the fire zones. The building floor can be divided into multiple smoke zones, by the use of supply and exhaust of air flows. The study investigate the control of air flows in the smoke zones using computer modeling and further comparison with field test results. It is shown that pressurization can prevent smoke entering in case of fire and is important for safe evacuation.
This study considers various parameters such as: the leakage area of walls, floors, partitions, doors and windows. The air volume of the air moving equipment is also included in the analysis. Computer program CONTAM as developed by NIST is used in the multi-zone air flow analysis. The flow infiltration and exfiltration across the outer and inner boundaries in the building is studied. The external wind pressure and temperature is included in the analysis of pressure zones.
Field test was carried out in an office building for validation of the computer analysis. Trace gas SF6 was release into a room in the nineteenth floor to simulate the smoke. Measurements pressure difference, air flow, wind speed, temperature, and trace gas concentration were in the different pressure zones on the same floor. Field test results confirm that the positive and negative pressure zoning is feasible to present smoke entering the relative higher pressure zones.
The measured results were compared with the simulation analysis and close agreement was found. The simulation shows that the pressure measurements along the evacuation route from the fire site agree well with the field test data. Moreover, the concentration of the trace gas SF6 was measured to be the background value along the evacuation route. It was also observed that the trace gas did not spread to the upper and lower floors. The above results obtained show the viability of pressurized zoning as an effective measure of smoke control.

並列關鍵字

pressurized zoning, building smoke control ； performance based design ； air conditioning air flow ； CONTAM

參考文獻

[1] R. S. Miller and D. Beasley, On stairwell and elevator shaft pressurization for smoke controlin tall buildings, Building and Environment, Vol 44, 2009, pp.1306-1317.

[6] NFPA 92A, Recommended Practice for Smoke-Control Systems, Chapter4-8, 1996.

[11] J.H. Klote and J.A. Milke, Principles of Smoke Management Systems, ASHRAE, Chpa12, 2002, pp.87–118 .

[17] ASHRAE Guideline 5, Commissioning Smoke Management Systems, 1994.

[2] A. K. Persily and E. M. Ivy, Input Data for Multizone Airflow and IAQ Analysis, NISTIR 6585, Jan 2001.