柴油机掺烧生物柴油燃烧过程的数值模拟研究
发布时间：2019-05-24 03:58
【摘要】：由于现有的能源资源过度开采和环境污染越来越严重,人们希望找到传统化石燃料的替代产品。生物柴油是一种可再生性替代燃料,以其原料来源广、污染小等特点越来越受到人们的关注。开展柴油机渗烧生物柴油燃烧过程的研究有较大的理论意义和应用前景。逡逑通过试验和数值模拟相结合的方式,研究了186FA柴油机渗烧不同比例生物柴油的燃烧和排放特性。在试验过程中柴油机不作任何调整,基于实测示功图分析比较了不同燃料的放热规律和燃烧噪声。结果表明:燃料中生物柴油的渗烧比率越大,缸内压力峰值也越大,峰值压力对应的曲轴转角越提前;同时放热率峰值降低,燃烧始点也有所提前;渗烧生物柴油提高了燃料的燃烧效率和经济性;渗烧生物柴油后,燃烧噪声增大。在相同负荷下,燃料的烟度值随生物柴油渗烧比的增大而减小,NOx排放量随生物柴油渗烧比的增加而增大。逡逑本文开展了柴油机渗烧生物柴油的燃烧和排放特性的数值模拟研究。在使用Pro-E软件进行燃烧室S维建模的基础上,利用HyperMe sh和AVL-F IRE软件进行燃烧室内网格的划分,并利用FIRE软件进行B0、B50、B100=种燃料的燃烧过程模拟。通过与实测示功图的比较,分析了κ-ε、LES和PANS模型的模拟精度,然后研究了不同渗烧比生物柴油的燃烧、喷雾及排放特性。模拟结果表明PANS模型预测燃烧始点、缸内最高爆发压力的精确度高于LE S模型,捕捉端流满团的能力强于标准κ-ε模型。渗烧生物柴油后,燃料的密度和粘度变大,使得B 5 0和B100燃料的喷雾贯穿距大于B0燃料,燃油着壁后附着于缸壁的燃油量较多,B50和B100燃料的雾化、蒸发和混合气形成情况比B0燃料差。由于生物柴油中的氧含量增大了局部空燃比,与B 0燃料相比,B 5 0和B10 0燃料有较高的局部燃烧n群蚇Ox排放物,在燃烧过程中B 5 0和B10 0燃料的化高浓度区域较广,有利于降低soot排放。优化满流比和喷油提前角能够控制soot和NOx污染物的生成量。逡逑
[Abstract]:Due to the overexploitation of existing energy resources and more serious environmental pollution, people hope to find alternatives to traditional fossil fuels. Biodiesel is a renewable alternative fuel, which has attracted more and more attention because of its wide source of raw materials and low pollution. It is of great theoretical significance and application prospect to study the combustion process of diesel engine infiltrated biodiesel. The combustion and emission characteristics of 186FA diesel engine with different proportion of biodiesel were studied by means of test and numerical simulation. The heat release law and combustion noise of different fuels are analyzed and compared based on the measured indicator diagram without any adjustment during the test. The results show that the higher the penetration ratio of biodiesel in fuel is, the greater the peak pressure in cylinder is, the earlier the crankshaft rotation angle corresponding to the peak pressure is, and the lower the peak exothermic rate is and the combustion starting point is also advanced. The combustion efficiency and economy of the fuel are improved by infiltrating biodiesel, and the combustion noise increases after the infiltration of biodiesel. Under the same load, the smoke value of fuel decreases with the increase of biodiesel penetration ratio, and the NOx emission increases with the increase of biodiesel penetration ratio. In this paper, the numerical simulation of combustion and emission characteristics of diesel engine infiltrated biodiesel is carried out. On the basis of S dimensional modeling of combustion chamber with Pro-E software, the grid of combustion chamber is divided by HyperMe sh and AVL-F IRE software, and the combustion process of B0, B50, B100 = fuel is simulated by FIRE software. By comparing with the measured indicator diagram, the simulation accuracy of k-蔚, LES and PANS models is analyzed, and then the combustion, spray and emission characteristics of biodiesel with different penetration ratio are studied. The simulation results show that the PANS model is more accurate than the LE S model in predicting the starting point of combustion, and the ability to capture the end flow is stronger than that of the standard k-e model. After infiltrating biodiesel, the density and viscosity of the fuel increase, so that the spray penetration distance of B50 and B100 fuel is greater than that of B0 fuel, and the fuel quantity attached to the cylinder wall is more than that of B50 and B100 fuel, and the atomization of B50 and B100 fuel is more than that of B50 and B100 fuel. Evaporation and mixture formation are worse than B 0 fuel. Because the oxygen content in biodiesel increases the local air fuel ratio, compared with B 0 fuel, B 50 and B 100 fuel have higher local combustion n? The high concentration range of B50 and B100 fuels in the combustion process is wide, which is beneficial to the reduction of soot emissions. Optimizing the full flow ratio and injection advance angle can control the formation of soot and NOx pollutants. Balk
【学位授予单位】：江苏大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TE667
本文编号：2484540
[Abstract]:Due to the overexploitation of existing energy resources and more serious environmental pollution, people hope to find alternatives to traditional fossil fuels. Biodiesel is a renewable alternative fuel, which has attracted more and more attention because of its wide source of raw materials and low pollution. It is of great theoretical significance and application prospect to study the combustion process of diesel engine infiltrated biodiesel. The combustion and emission characteristics of 186FA diesel engine with different proportion of biodiesel were studied by means of test and numerical simulation. The heat release law and combustion noise of different fuels are analyzed and compared based on the measured indicator diagram without any adjustment during the test. The results show that the higher the penetration ratio of biodiesel in fuel is, the greater the peak pressure in cylinder is, the earlier the crankshaft rotation angle corresponding to the peak pressure is, and the lower the peak exothermic rate is and the combustion starting point is also advanced. The combustion efficiency and economy of the fuel are improved by infiltrating biodiesel, and the combustion noise increases after the infiltration of biodiesel. Under the same load, the smoke value of fuel decreases with the increase of biodiesel penetration ratio, and the NOx emission increases with the increase of biodiesel penetration ratio. In this paper, the numerical simulation of combustion and emission characteristics of diesel engine infiltrated biodiesel is carried out. On the basis of S dimensional modeling of combustion chamber with Pro-E software, the grid of combustion chamber is divided by HyperMe sh and AVL-F IRE software, and the combustion process of B0, B50, B100 = fuel is simulated by FIRE software. By comparing with the measured indicator diagram, the simulation accuracy of k-蔚, LES and PANS models is analyzed, and then the combustion, spray and emission characteristics of biodiesel with different penetration ratio are studied. The simulation results show that the PANS model is more accurate than the LE S model in predicting the starting point of combustion, and the ability to capture the end flow is stronger than that of the standard k-e model. After infiltrating biodiesel, the density and viscosity of the fuel increase, so that the spray penetration distance of B50 and B100 fuel is greater than that of B0 fuel, and the fuel quantity attached to the cylinder wall is more than that of B50 and B100 fuel, and the atomization of B50 and B100 fuel is more than that of B50 and B100 fuel. Evaporation and mixture formation are worse than B 0 fuel. Because the oxygen content in biodiesel increases the local air fuel ratio, compared with B 0 fuel, B 50 and B 100 fuel have higher local combustion n? The high concentration range of B50 and B100 fuels in the combustion process is wide, which is beneficial to the reduction of soot emissions. Optimizing the full flow ratio and injection advance angle can control the formation of soot and NOx pollutants. Balk
【学位授予单位】：江苏大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TE667
【参考文献】
相关期刊论文 前1条
1 毛功平;王忠;许广举;李铭迪;;生物柴油燃烧过程中氧、氮元素的迁移历程分析[J];车用发动机;2011年04期
，本文编号：2484540
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