1673-159X

CN 51-1686/N

氢气射流点燃氨气火焰发展特性数值模拟研究

Numerical Simulation Study on the Flame Development Characteristics of Ammonia Ignited by Hydrogen Jet

  • 摘要: 基于CFD方法,采用Converge流体仿真软件对氢气射流点燃氨气燃烧特性进行分析,研究不同预燃室当量比和不同主燃室当量比下射流火焰发展情况、射流强度、化学组分变化及主燃室湍动能的变化。仿真结果表明:预燃室的当量比对射流点燃效果的影响明显,固定主燃室当量比为0.8,随着预燃室当量比从1.0增加到1.6,预燃室射流点火效果先增强后减弱,当量比为1.2时具有最佳射流引燃效果。固定预燃室当量比为1.2时,随着主燃室当量比从0.6增加到1.0,主燃室火焰发展速度也在提高,在主燃室当量比为1.0时,主燃室具有最佳的火焰发展速度及燃烧效果。主燃室中湍流影响射流物质与主燃室物质的交换,湍动能变化越大,在定容燃烧弹内引起的扰动就越大,燃烧速度就越快。

     

    Abstract: Based on the CFD method, the hydrogen jet ignition characteristics of ammonia combustion were analyzed by Converge fluid simulation software. The development of jet flames, jet intensity, changes in chemical composition, and variations in turbulent kinetic energy in the main combustion chamber were studied under different equivalence ratios in the pre-chamber and main combustion chamber. The results from the simulation indicated that the equivalence ratio in the pre-chamber had a significant effect on the jet ignition performance. When the equivalence ratio in the main combustion chamber was fixed at 0.8 and the pre-chamber equivalence ratio increased from 1.0 to 1.6, the jet ignition effect in the pre-chamber was initially enhanced and then weakened. The best jet ignition effect was observed at an equivalence ratio of 1.2. When the equivalence ratio in the pre-chamber was fixed at 1.2 and the main combustion chamber equivalence ratio increased from 0.6 to 1.0, the flame development speed in the main combustion chamber increased. The best flame development speed and combustion performance were exhibited when the equivalence ratio was 1.0. The turbulence in the main combustion chamber affected the exchange of matter between the jet and the main combustion chamber. The greater the variation in turbulence kinetic energy, the greater the disturbance caused inside the constant volume combustion bomb, and the faster the combustion rate.

     

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