介绍无烟气持续渗入竖井和有烟气持续渗入竖井的中性面与质量流率计算模型,研究火灾时竖井的烟囱效应.根据质量平衡与热量平衡推导竖井开口质量流率与竖井内部压力中性面位置的计算方法,并进行简化.选取横截面内部尺寸为4 m×4 m、高度为304 m、顶部与底部开口的面积4 m2的竖井,设定火灾烟气从50 m高处连续渗入到竖井内部空间,渗入烟气的初始温度为177℃,烟气渗入的质量流率为10、20、30 kg/s,对比分析理论计算结果与FDS模拟结果.研究发现,KLOTE模型获得的压力中性面位置明显高于数值模拟结果,且该偏差会随着烟气渗入质量流率的增大而增大.提出的简化计算方法与数值模拟结果的差异较小,具有可靠性与高效性.%The calculation models of neutral plane location and the mass flow rate with or without smoke penetration were introduced to research the stack effect in shaft in fire. The mass balance and heat balance equations were proposed and analyzed and the calcula-tion methods for the vent flow rate and neutral plane location of a shaft were deduced, and the corresponding simplified calculation method was proposed. Taking a shaft with cross section of 4 m × 4 m and height of 304 m as example, the exits on top or bottom were 4 m2, the smoke penetrated from 50 m from bottom, the mass flow rate were 10, 20 and 30 kg/s, the theoretical calculation results were compared against the numerical simulations performed by FDS. The results showed that the neutral plane locations predicted by the traditional Klote′s model are generally higher than the nu-merical simulation results, and the discrepancy between the Klote′s model and the FDS simulation result increases with the in-crease of flow rate of smoke penetration. The simplified calculation method has good capability in stack effect prediction and high cal-culation efficiency as well.
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