Effects of ethanol enrichment on in-cylinder thermochemical fuel reforming (TFR) spark ignition natural gas engine
Effects of ethanol enrichment on in-cylinder thermochemical fuel reforming (TFR) spark ignition natural gas engine
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DOI：
10.1016/j.fuel.2017.02.053
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发表时间：
2017-06
期刊：
影响因子：
7.4
通讯作者：
Zhuoyao He;Lei Zhu;Zhengxia Xu;O. Kaario;Ang Li;Zhen Huang
中科院分区：
文献类型：
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作者：
Zhuoyao He;Lei Zhu;Zhengxia Xu;O. Kaario;Ang Li;Zhen Huang
在这项研究中，在四缸火花点火天然气 (NG) 发动机上检验了缸内热化学燃料重整 (TFR) 的概念，该概念涉及使一个气缸充满化学计量并将其全部废气送回进气歧管。额外的天然气燃料（NG浓缩）通过端口喷射到#4气缸（TFR气缸）以实现其浓运行。结果表明，当TFR气缸的当量比(Φ TFR)约为1.25时，重整气中含有大量H 2 和CO，#2气缸(典型的#1、2和3气缸)的燃烧得到显着改善。然而，随着Φ TFR 的增大，不仅TFR 气缸的稳定性变差，而且#2 气缸与TFR 气缸的IMEP 差异也显着增大。为了提高发动机性能，进行了使用乙醇代替天然气加浓 TFR 气缸的试验。结果表明，乙醇富集提高了重整气中H 2 和CO的浓度，使发动机运行更加稳定。此外，乙醇浓缩还降低了#2气缸和TFR气缸之间的IMEP差异，表明发动机均匀性更好。然而，与天然气浓缩相比，乙醇浓缩并没有严重影响发动机HC和CO排放，同时显着降低了NOx排放。
In this study, the concept of in-cylinder thermochemical fuel reforming (TFR), which involves running one cylinder rich of stoichiometric and routing its entire exhaust back into the intake manifold, were examined on a four-cylinder spark ignition natural gas (NG) engine. Extra natural gas fuel (NG enrichment) was port injected into cylinder# 4 (TFR cylinder) to realize its rich running. Results indicated that the combustion of cylinder# 2 (typical of cylinder# 1, 2 and 3) was significantly improved with substantial H 2 and CO fraction in the reformed gas when equivalence ratio of TFR cylinder (Φ TFR) was about 1.25. However, not only the stability of TFR cylinder was worsened, but also the discrepancy of IMEP between cylinder# 2 and TFR cylinder remarkably increased with the increase of Φ TFR. To improve engine performances, a trial of enriching TFR cylinder using ethanol instead of NG was performed. Results manifested that ethanol enrichment improved H 2 and CO concentration in reformed gas and led to a more stable engine operation. Besides, ethanol enrichment also lowered the discrepancy of IMEP between cylinder# 2 and TFR cylinder, indicating a better engine uniformity. However, ethanol enrichment did not severely affect engine HC and CO emissions while remarkably lowered NOx emission compared with NG enrichment.