Maximum smoke temperature beneath the ceiling in an enclosed channel with different fire locations. (25th January 2017)

• Record Type: Journal Article
• Authors: Yao, Yongzheng; Cheng, Xudong; Zhang, Shaogang; Zhu, Kai; Zhang, Heping; Shi, Long
• Is Part Of: Applied thermal engineering. Volume 111(2017:Jan.)
• Page Start: 30
• Page End: 38
• Publication Date: 2017-01-25
• Subjects: Maximum smoke temperature -- Enclosed channel -- Fire location -- Smoke movement -- Flame inclination; Heat engineering -- Periodicals; Heating -- Equipment and supplies -- Periodicals; Periodicals; 621.40205
• DOI: 10.1016/j.applthermaleng.2016.08.161
• Languages: English
• ISSNs: 1359-4311

Abstract

Highlights: Maximum smoke temperature was studied by a reduced-scale enclosed channel model. Fire locations showed significant influence on the maximum smoke temperature. Existing model was improved to predict maximum smoke temperature in enclosed channel. The improved model obeys reasonably well with the experimental results. Abstract: Smoke movement and the temperature beneath the ceiling in enclosed channel were investigated experimentally and theoretically. The experimental results show that the maximum smoke temperature decreases with an increasing flame inclination angle when fire source is moving away from the channel center in Region I (within the dimensionless distance for 0.64), which is caused by the gas velocity difference of the two sides of flame. However, when the dimensionless distance is >0.64, the maximum smoke temperature was observed to rise. In addition, an existing model was improved to predict the maximum smoke temperature in enclosed channel applying it to different boundary conditions. Its predictions fit reasonably well when the fire source located at Region I. Beyond that, the predictions are lower than the experiments, which is probably because of the absent consideration of bouncing process of the hot smoke from end walls. Therefore, an extra correction coefficient was proposed to the improved model in Region II with a consideration of bouncing process of the hot smoke from both end walls. As a result, it was found that the experimental results can be well predicted by this model in Region II.