焦炉气燃料发动机工作过程数值模拟与参数优化

发布时间：2018-03-21 13:20

本文选题：焦炉气燃料发动机　切入点：工作过程　出处：《贵州大学》2016年硕士论文　论文类型：学位论文

【摘要】：近十年,我国汽车保有量增长了3倍,汽车方便了出行的同时,消耗了大量石油资源,也一定程度的污染了社会环境。去年,中国生产焦炭4.48亿吨,伴随产生近2000亿立方米焦炉气,其中一半回炉作为燃料使用,剩下的一半中的大部分被浪费掉。项目参与企业前期研究表明,经过净化后的焦炉气基本满足车用发动机使用要求,能够在汽车发动机上直接使用。但是直接将汽油换成焦炉气使用,依然存在动力性下降较大、经济性差以及其他问题。首先,本文指出了汽车产销及保有量飞速上涨与焦炉气大量浪费的现状,研究了发动机对替代燃料的要求,以及目前各种替代燃料的分类及特点,对比了世界上多个国家的气体发动机和焦炉气燃料发动机研究及使用情况,研究了4种发动机缸内燃烧模型及2种发动机工作过程仿真软件,确定了研究对象及其主要参数以及主要研究内容及方法。其次,参阅相关文献资料,研究了焦炉气及其主要组分的物理特点及化学燃烧特点,并重点研究了氢气、甲烷在气缸内部燃烧的燃烧特性,作为后续工作过程研究的理论基础。然后,将焦炉气简化为多组分的理想混合气,基于理想混合气系统总参数的加和性,以理化参数理论计算公式为基础,利用所建焦炉气理化参数Simulink计算模型,方便快速的计算出了焦炉气的部分主要理化参数数值。再次,研究了内燃机整机性能计算的建模理论基础,并以某型V6汽油发动机为原机型,利用BOOST仿真软件建立了一维的发动机工作过程计算模型,并利用该模型计算了该型发动机分别燃用汽油与焦炉气时,转矩、功率以及燃油消耗率情况。对比发现:燃用焦炉气与燃用汽油相比,该型发动机燃油消耗率减少3%-4%,燃油经济性提高很少,但转矩和功率最高降低近20%,动力性降低较大。最后,以所建的某V6汽油机BOOST一维模型为基础,以焦炉气为燃料,先后对增压比、压缩比、点火提前角、空燃比以及配气相位进行了仿真研究并进行了适当修正,最终将增压比选择为2.08、压缩比为9.5、点火提前角为1°CA、空燃比为17.5、进气门关闭延迟角为57°CA,排气门开启提前角为63°CA,该型发动机燃用焦炉气后,优化后与优化前相比,动力性最高提升约7.25%,经济性最高提升近30%。总之,优化后,该机型焦炉气燃料发动机动力性、经济性均得到不同程度改善。
[Abstract]:In the past ten years, the number of cars in China has increased threefold. While the cars are convenient to travel, they have consumed a lot of oil resources and polluted the social environment to a certain extent. Last year, China produced 448 million tons of coke. With the production of nearly 200 billion cubic meters of coke oven gas, half of the return furnace is used as fuel, and most of the remaining half are wasted. The purified coke oven gas basically meets the requirements of the vehicle engine and can be used directly on the automobile engine. However, if the gasoline is directly replaced by the coke oven gas, the power performance will still decline greatly. First of all, this paper points out the current situation of the rapid increase of automobile production, sales and possession and the waste of coke oven gas, studies the requirements of the engine for alternative fuels, and the classification and characteristics of various alternative fuels at present. The research and application of gas engine and coke oven gas engine in many countries in the world are compared. Four kinds of in-cylinder combustion models and two kinds of simulation software of engine working process are studied. The main research object, main parameters, main contents and methods are determined. Secondly, the physical characteristics and chemical combustion characteristics of coke oven gas and its main components are studied, and the hydrogen gas is emphatically studied. The combustion characteristics of methane combustion in cylinder are used as the theoretical basis for further research. Then, the coke oven gas is simplified as a multi-component ideal mixture, and the summation of total parameters of ideal mixture system is considered. Based on the theoretical calculation formula of physical and chemical parameters and the Simulink calculation model of coke oven gas physical and chemical parameters, some main physical and chemical parameters of coke oven gas are calculated conveniently and quickly. In this paper, the theoretical foundation of modeling for the performance calculation of internal combustion engine is studied. Taking a V6 gasoline engine as the original model, a one-dimensional working process calculation model of the engine is established by using the BOOST simulation software. The torque, power and fuel consumption rate of the engine are calculated by using the model when the engine is burned with gasoline and coke oven gas respectively. The fuel consumption of this type of engine is reduced by 3% to 4%, the fuel economy is improved very little, but the maximum torque and power are reduced by nearly 20%, and the power performance is greatly reduced. Finally, based on the BOOST one-dimensional model of a V6 gasoline engine, the coke oven gas is used as fuel. The pressurization ratio, compression ratio, ignition advance angle, air-fuel ratio and gas distribution phase are simulated and modified. Finally, the turbocharging ratio is 2.08, the compression ratio is 9.5, the ignition advance angle is 1 掳CA, the air-fuel ratio is 17.5, the inlet valve closing delay angle is 57 掳CA, and the exhaust valve opening advance angle is 63 掳CA.After using coke oven gas, the optimized engine is compared with that before optimization. The maximum power performance is about 7.25 and the economy is about 30. In a word, after the optimization, the power performance and economy of the coke oven gas engine are improved to some extent.
【学位授予单位】：贵州大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：U464

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