Experimental studies on the key parameters controlling the combustion and emission in premixed charge compression ignition concept based on diesel surrogates
Experimental studies on the key parameters controlling the combustion and emission in premixed charge compression ignition concept based on diesel surrogates
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DOI：
10.1016/j.apenergy.2018.10.104
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发表时间：
2019-02
期刊：
影响因子：
11.2
通讯作者：
Yong Qian;Zhiyong Wu;Jinjing Guo;Zilong Li;Chenxu Jiang;Xingcai Lu
中科院分区：
文献类型：
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作者：
Yong Qian;Zhiyong Wu;Jinjing Guo;Zilong Li;Chenxu Jiang;Xingcai Lu
与传统的柴油机燃烧模式相比，预混充气压缩点火模式只改变了燃油喷射策略，并结合一定比例的废气再循环，对发动机整体性能影响不大。研究柴油十六烷值和挥发分对预混充气压缩着火方式的燃烧、排放和负荷范围扩展的影响。本文以多组分代用燃料为研究对象，通过改变代用燃料的组成及其比例，结合燃油喷射参数的调整，控制柴油代用燃料的十六烷值和挥发分，研究影响预混充气压缩点火方式燃烧和排放的因素。在相同的喷射策略下，燃料的十六烷值在燃烧阶段起决定性作用。直喷燃料十六烷值降低导致CO和HC排放增加。低十六烷值燃料有助于抑制飞行员喷射燃料的过早燃烧。燃料十六烷值的降低可以抑制累积颗粒物的排放。改变燃料的挥发度对燃烧阶段和燃烧速度的影响有限。高挥发分燃料在预混压燃模式下虽然不能从根本上解决预混策略带来的高CO和HC排放问题，但能有效降低CO和HC的排放。增加燃料的挥发度可以降低累积颗粒的浓度。在通过调整喷油参数保证NOx排放低于200ppm的前提下，增加燃油挥发度可以使指示油耗降低到178ppm/ 。
Compared with the traditional diesel combustion mode, the premixed charge compression ignition mode only changes the fuel injection strategy combined with a certain ratio of exhaust gas recirculation, which needs little change to the overall engine. Studies on the effects of the cetane number and volatility of the diesel fuels are critical to the combustion, emissions and load range expansion of the premixed charge compression ignition mode. Based on the multi-component surrogate fuels, this paper controlled the cetane number and the volatility of diesel surrogates by changing the components and their proportions combined with the adjustment of fuel injection parameters to study the factors that affect the combustion and emissions of the premixed charge compression ignition mode. The cetane number of fuels played a decisive role in the combustion phase under the same injection strategy. The decrease of cetane number of the direct injected fuels led to the increase of CO and HC emissions. Low cetane fuels helped to inhibit premature combustion of pilot injected fuel. The decrease in fuel cetane number could suppress the emissions of accumulated particles. Changing the volatility of the fuel had limited effects on the combustion phase and combustion speed. High volatility fuel could effectively reduce the CO and HC emissions in the premixed charge compression ignition mode although it cannot fundamentally solve the high CO and HC emission problems caused by the premixed strategy. Increasing the volatility of the fuel could reduce the concentration of accumulated particles. Under the premise of ensuring that the NOx emissions were lower than 200 ppm via adjusting the injection parameters, increasing fuel volatility may decrease the indicated fuel consumption as low as 178 g/kWh.