Experimental study on thermal efficiency and emission characteristics of a lean burn hydrogen enriched natural gas engine
Experimental study on thermal efficiency and emission characteristics of a lean burn hydrogen enriched natural gas engine
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DOI：
10.1016/j.ijhydene.2007.07.048
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发表时间：
2007-12
影响因子：
7.2
通讯作者：
Fanhua Ma;Yu Wang;Haiquan Liu;Yong Li;Junjun Wang;Shuli Zhao
中科院分区：
文献类型：
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作者：
Fanhua Ma;Yu Wang;Haiquan Liu;Yong Li;Junjun Wang;Shuli Zhao
为了分析掺氢对天然气发动机热效率和排放的影响，在火花点火天然气发动机上进行了可变组分氢气/天然气混合气（HCNG）的试验研究。结果表明，富氢可显著延长发动机的稀燃极限，提高发动机的稀燃能力，缩短燃烧持续期。然而，氮氧化物（NOx）被发现增加与氢除了如果火花正时没有根据氢的高燃烧速度进行优化。还发现，当点火正时设定为恒定时，由于更小的淬火距离和更高的燃烧温度，添加氢气实际上增加了从气缸向外的热传递，因此如果与非理想点火正时的影响相结合，则不利于提高热效率。但如果点火提前角延迟到MBT，利用氢气燃烧速度快的特点，添加氢气后NOx排放没有明显增加，发动机热效率随着氢气含量的增加而提高。未燃碳氢随氢分率的增加而减少。
In order to analyze the effect of hydrogen addition on natural gas (NG) engine's thermal efficiency and emission, an experimental research was conducted on a spark ignition NG engine using variable composition hydrogen/CNG mixtures (HCNG). The results showed that hydrogen enrichment could significantly extend the lean operation limit, improve the engine's lean burn ability, and decrease burn duration. However, nitrogen oxides (NOx) were found to increase with hydrogen addition if spark timing was not optimized according to hydrogen's high burn speed. Also found when spark timing was set at constant was that hydrogen addition actually increases heat transfer out of the cylinder due to smaller quenching distance and higher combustion temperature, thus is not good to improve thermal efficiency if combined with the effect of non-ideal spark timing. But if spark timing was retarded to MBT, taking advantage of hydrogen's high burn speed, NOxemissions exhibited no obvious increase after hydrogen addition and engine thermal efficiency increased with the increase of hydrogen fraction. Unburned hydrocarbon always decreased with the increase of hydrogen fraction.