朱小玄，王华，左承基   

    摘要：本文分别建立了天然气发动机所需燃气、空气流量的数学模型，以及文丘里管混合器结构参数的数学模型。在Matlab / Simulink仿真平台上进行了建模和仿真，获得了设计工况下文丘里管混合器的结构参数，并在发动机运行范围内满足过量空气系数稳定在1.7左右的设计要求。

    关键词：天然气发动机；文丘里管混合器；仿真模型；过量空气系数

    Abstract: This paper established the mathematical model considering gas flow and air flow required by a natural gas engine and the model of the structural parameters of a venturi mixer. The structural parameters of the mixer under design conditions were obtained according to the modeling and simulation on the Matlab/Simulink. The simulation result shows that the established mixer modeling meets the design requirements that the excess air coefficient is around 1.7 as the engine is operating.

    Key Words: Natural Gas Engine; Venturi Mixer; Simulation Model, Excess Air Coefficient