内燃机尾气余热重整制氢混燃性能试验

Mixed Combustion Performance Experiment of Syngas Produced by Ethanol Steam Reforming for Engine

摘要:

针对氢气在汽车上不易存储和携带的问题，利用自行设计的一套燃料重整制氢系统回收发动机尾气余热，实现乙醇水蒸气重整制氢。通过改装发动机进气管，将制取的重整气引入发动机，和汽油一起实现混合燃烧。试验中汽油机的转速为1800r/min，进气压力为61.5kPa，在不同的过量空气系数下，分别对原机和重整气掺混体积分数2.5%的汽油机的性能进行研究。研究结果表明，随着过量空气系数的增大，重整气中氢气的体积分数越来越大，而一氧化碳的变化趋势则相反。重整气的引入缩短了火焰发展期和快速燃烧持续期，提高了发动机的指示热效率，并降低了HC的排放量，而CO和NOx的排放量略有增加。

Abstract:

Aiming at solving the difficulties in hydrogen on-board storage and carriage, a self-designed system was designed in an SI gasoline engine to recover the exhaust heat and produce hydrogen by the ethanol steam reforming. The engine intake manifolds were specially modified so that the produced syngas could be injected and mixed with gasoline simultaneously. During the experiment, the engine was kept at 1800r/min and a manifolds absolute pressure of 61.5kPa. The combustion and emissions performance of the 2.5% syngas-enriched gasoline engine was compared with that of the original engine under various excess air ratios. The experimental results demonstrated that the enhancement of excess air ratio could improve the hydrogen volume fraction whereas reduce the CO concentration in the syngas. The blending of syngas was beneficial for accelerating the flame development and propagation, elevating the indicated thermal efficiency and reducing the HC emissions. Meanwhile, the CO and Nox emissions were slightly increased after the syngas addition.