公路隧道侧壁排烟系统效率计算方法优化研究

Optimization study of highway tunnel lateral exhaust smoke system efficiency calculation method

排烟系统效率及排烟系统输出量是定量评价侧壁排烟系统性能的两个重要全局参数,一般基于烟气中CO/CO2输运特性对排烟系统效率进行间接评价,尚无直接计算方法。采用数值模拟的方式,在定性分析排烟口附近烟气温度(波动)分布及速度矢量分布规律基础上,提出一种计算额定排烟质量流率中烟气流率的方法,进而可求得上述参数。计算结果表明:利用该方法计算的各排烟口排烟效率与传统方法计算结果误差均在20%以内,说明两种方法计算结果都具有一定的参考价值;该方法能直接计算排烟系统效率及排烟系统输出量,相较于传统方法,物理意义更加明确;基于计算结果得出相关规律,为侧壁排烟系统的优化设计提供参考。

Ventilation System Efficiency(VSE)and Ventilation System Output(VSO)are important global parameters evaluating lateral exhaust smoke system property.Traditional method evaluates the efficiency based on CO/CO2 transport properties and there is no direct method to calculate these two parameters.Based on the qualitative analysis of distribution of temperature(fluctuation)and velocity vector near the smoke vent by numerical simulation,a new method to calculate the flue gas flow rate in rated smoke exhaust mass flow rate was put forward.The calculated results showed that compared to the tradition method,the difference ratio of ventilation efficiency at all smoke vents calculated by this method was less than 20%,that means the results calculated by both methods are meaningful.The superiority of the new method is that VSE and VSO can be calculated directly with explicit physical significance.At last,some laws have been acquired which is meaningful for lateral exhaust smoke system design.