Effect of hydrogen addition on combustion and emissions performance of a spark ignition gasoline engine at lean conditions
Effect of hydrogen addition on combustion and emissions performance of a spark ignition gasoline engine at lean conditions
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DOI：
10.1016/j.ijhydene.2009.06.082
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发表时间：
2009-09-01
影响因子：
7.2
通讯作者：
Wang, Shupfeng
中科院分区：
文献类型：
--
作者：
Ji, Changwei;Wang, Shupfeng
氢气具有许多优异的燃烧特性，可用于改善汽油燃料火花点火（SI）发动机的燃烧和排放性能。本文在四缸1.6 L发动机上进行了实验研究，探讨加氢对增强发动机稀薄运行性能的影响。对该发动机进行改造，在进气歧管内安装4个氢气喷射器，实现氢气端口喷射。氢气和汽油的喷射时间和持续时间由自主开发的电子控制单元（DECU）根据校准计算机的命令控制。发动机以 1400 rpm 的转速、61.5 kPa 的歧管绝对压力 (MAP) 和各种过量空气比运行。采用总进气量中3%和6%的两个氢气体积分数来检验氢气添加分数对发动机燃烧的影响。试验结果表明，加氢后制动热效率得到提高，并在较宽的过量空气比范围内基本保持恒定，最大制动热效率由原发动机的26.37%提高到掺氢水平6%发动机的31.56%。然而，在化学计量条件下，制动平均有效压力（Bmep）因添加氢气而降低，但当发动机进一步倾斜时，制动平均有效压力（Bmep）随着氢气添加比例的增加而增加。添加氢气可减少火焰形成和传播持续时间、循环变化、HC 和 CO2 排放。当过量空气比接近化学计量条件时，CO排放量随着氢气的添加而增加。然而，当发动机逐渐倾斜时，富氢发动机的CO排放量低于原来的发动机。由于汽缸温度升高，NOx 排放随着氢添加量的增加而增加。 (C) 2009 T. Nejat Veziroglu 教授。由爱思唯尔有限公司出版。保留所有权利。
Hydrogen has many excellent combustion properties that can be used for improving combustion and emissions performance of gasoline-fueled spark ignition (SI) engines. In this paper, an experimental study was carried out on a four-cylinder 1.6 L engine to explore the effect of hydrogen addition on enhancing the engine lean operating performance. The engine was modified to realize hydrogen port injection by installing four hydrogen injectors in the intake manifolds. The injection timings and durations of hydrogen and gasoline were governed by a self-developed electronic control unit (DECU) according to the commands from a calibration computer. The engine was run at 1400 rpm, a manifold absolute pressure (MAP) of 61.5 kPa and various excess air ratios. Two hydrogen volume fractions in the total intake of 3% and 6% were applied to check the effect of hydrogen addition fraction on engine combustion. The test results showed that brake thermal efficiency was improved and kept roughly constant in a wide range of excess air ratio after hydrogen addition, the maximum brake thermal efficiency was increased from 26.37% of the original engine to 31.56% of the engine with a 6% hydrogen blending level. However, brake mean effective pressure (Bmep) was decreased by hydrogen addition at stoichiometric conditions, but when the engine was further leaned out Bmep increased with the increase of hydrogen addition fraction. The flame development and propagation durations, cyclic variation, HC and CO2 emissions were reduced with hydrogen addition. When excess air ratio was approaching stoichiometric conditions, CO emission tended to increase with the addition of hydrogen. However, when the engine was gradually leaned out, CO emission from the hydrogen-enriched engine was lower than the original one. NOx emissions increased with the increase of hydrogen addition due to the raised cylinder temperature. (C) 2009 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved.