• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Fuel >Experimental study on the auto-ignition and combustion characteristics in the homogeneous charge compression ignition (HCCI) combustion operation with ethanol-heptane blend fuels by port injection
【24h】

Experimental study on the auto-ignition and combustion characteristics in the homogeneous charge compression ignition (HCCI) combustion operation with ethanol-heptane blend fuels by port injection

机译：进气道喷射乙醇/正庚烷混合燃料在均质充量压缩点火（HCCI）燃烧操作中自燃和燃烧特性的实验研究

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

This article investigates the auto-ignition, combustion, and emission characteristics of homogeneous charge compression ignition (HCCI) combustion engines fuelled with n-heptane and ethanol-heptane blend fuels. The experiments were conducted on a single-cylinder HCCI engine using neat n-heptane, and 10 percent, 20 percent, 30 percent, 40 percent, and 50 percent ethanol-heptane blend fuels (by volume) at a fixed engine speed of 1800 r/min. The results show that, with the introduction of ethanol in n-heptane, the maximum indicated mean effective pressure (IMEP) can be expanded from 3.38 bar of neat n-heptane to 5.1 bar, the indicated thermal efficiency can also be increased up to 50 percent at large engine loads, but the thermal efficiency deteriorated at light engine load. Due to the much higher octane number of ethanol, the cool-flame reaction delays, the initial temperature corresponding the cool-flame reaction increases, and the peak value of the low-temperature heat release decreases with the increase of ethanol addition in the blend fuels. Furthermore, the low-temperature heat release is indiscernible when the ethanol volume increases up to 50 percent. In the case of the neat n-heptane and 10 percent ethanol-heptane blends, the combustion duration is very short due to the early ignition timing. For 20-50 percent ethanol-heptane blend fuels, the ignition timing is gradually delayed to the top dead center (TDC) by the ethanol addition. As a result, the combustion duration prolongs obviously at the same engine load when compared to the neat n-heptane fuel. At overall stable operation ranges, the HC emissions for n-heptane and 10-30 percent ethanol-heptane blends are very low, while HC emissions increase substantially for 40 percent and 50 percent ethanol-heptane blends. CO emissions show another tendency compared to HC emissions. At the engine load of 1.5-2.5 bar, CO emissions are very high for all fuels. Beside this range, CO emissions decrease both for large load and light load. In terms of operation stability of HCCI combustion, for a constant energy input, n-heptane shows an excellent repeatability and light cycle-to-cycle variation, while the cycle-to-cycle variation of the maximum combustion pressure and its corresponding crank angle, and ignition timing deteriorated with the increase of ethanol addition.
机译：本文研究了以正庚烷和乙醇/正庚烷混合燃料为燃料的均质充量压燃式（HCCI）内燃机的自燃，燃烧和排放特性。实验是在使用纯正庚烷和10％，20％，30％，40％和50％乙醇/正庚烷混合燃料（按体积计）的单缸HCCI发动机上进行的，固定转速为1800转/分钟结果表明，在正庚烷中引入乙醇后，最大指示平均有效压力（IMEP）可以从纯正庚烷的3.38 bar扩大到5.1 bar，指示热效率也可以提高到50在大发动机负载下，热效率降低了5％，而在轻发动机负载下，热效率降低了。由于乙醇的辛烷值高得多，冷焰反应延迟，与冷焰反应相对应的初始温度升高，并且随着混合燃料中乙醇添加量的增加，低温放热的峰值降低。 。此外，当乙醇体积增加到50％时，低温放热是不明显的。在纯正庚烷和10％乙醇/正庚烷混合物的情况下，由于提前点火正时，燃烧持续时间非常短。对于20-50％的乙醇/正庚烷混合燃料，通过添加乙醇，点火正时逐渐延迟到上止点（TDC）。结果，与纯正庚烷燃料相比，在相同发动机负载下，燃烧持续时间明显延长。在总体稳定运行范围内，正庚烷和10％至30％的乙醇/正庚烷混合物的HC排放量非常低，而HC排放量对于40％和50％的乙醇/正庚烷混合物的HC排放量显着增加。与HC排放相比，CO排放显示出另一种趋势。在1.5-2.5 bar的发动机负载下，所有燃料的CO排放量都很高。超出此范围，无论是大负荷还是轻负荷，CO排放量都会减少。就HCCI燃烧的运行稳定性而言，对于恒定的能量输入，正庚烷具有出色的可重复性和轻巧的周期变化，而最大燃烧压力及其对应的曲柄角的周期变化，随着乙醇添加量的增加，点火正时变差。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号