对于采用止回阀的集中排烟道系统 ,通过建立连续性方程及各流线上的能量方程 ,计算出采用普通排油烟机时在不同截面下烟道内沿程的流量及压力分布。分析表明由于温差很小 ,热压对流动的影响力较小 ,烟气流动的动力主要来自于排烟机本身。烟道内压力自上而下逐渐增加 ,底层住户的排烟最为不利。计算方程和程序可用于工程设计。 For the centralized exhaust duct system with check valve, the flow and pressure distribution along the flue duct with different cross sections were calculated by establishing the continuity equation and the energy equation of each streamline. The analysis shows that due to the small temperature difference, the influence of hot pressing on the flow is small, and the power of the flue gas flow mainly comes from the smoke exhausting machine itself. The pressure inside the flue gradually increased from top to bottom, the bottom of the households smoke the most adverse. Calculation equations and procedures are available for engineering design.