發(fā)布時間：2018-04-30 03:37

  本文選題：柴油機(jī) + 變組分進(jìn)氣��； 參考：《吉林大學(xué)》2016年碩士論文

【摘要】：本文提出了變組分進(jìn)氣對柴油機(jī)燃燒特性和排放特性影響的研究,該項技術(shù)通過改變發(fā)動機(jī)進(jìn)氣中各類組分的濃度,能夠有效改善柴油機(jī)的燃燒特性,同時降低諸多有害氣體的排放,并且能夠改善高海拔環(huán)境下發(fā)動機(jī)著火困難、動力性下降、熱效率低、燃燒不完全等一系列問題。不過目前該項技術(shù)手段還處于研究階段,距離實際應(yīng)用還存在很多技術(shù)問題。本文研究的變組分進(jìn)氣對柴油機(jī)的燃燒特性和排放特性的影響。主要分為兩部分,一部分是富氧進(jìn)氣燃燒,另一部分是富氮進(jìn)氣燃燒。為了實現(xiàn)研究目的,本文采用Chemkin-pro和AVL-Fire進(jìn)行相關(guān)的模擬分析。首先是利用Chemkin-pro建立正庚烷化學(xué)反應(yīng)機(jī)理,為了能夠更好的預(yù)測變組分進(jìn)氣對柴油機(jī)排放特性的影響,在原有化學(xué)反應(yīng)機(jī)理的基礎(chǔ)上添加NO生成的機(jī)理模型,由此建立了新的化學(xué)反應(yīng)機(jī)理。將利用Pro/e建立的幾何模型導(dǎo)入AVL-Fire生成動網(wǎng)格。本文在研究富氧進(jìn)氣燃燒的過程中,分別設(shè)置了4種不同的富氧進(jìn)氣濃度,分別為23%、25%、27%和29%,研究了與自然進(jìn)氣狀態(tài)下相比的溫度、放熱率、累計放熱率、壓力、壓力升高率等相關(guān)參數(shù)的變化趨勢。通過研究發(fā)現(xiàn)隨著進(jìn)氣氧氣濃度的升高,這些參數(shù)都有不同程度的升高,因此富氧進(jìn)氣能夠有效增加柴油機(jī)工作過程中的動力性。在研究富氧進(jìn)氣對柴油機(jī)排放特性的影響時發(fā)現(xiàn),低溫和缺氧是導(dǎo)致CO生成的主要因素,因此富氧進(jìn)氣可以有效降低CO的排放量。為了研究富氧進(jìn)氣對HC生成量的影響,選取CH3、CH4、CH3O、CH2O、C2H5和C3H6六種主要生成物最為研究對象,通過模擬分析發(fā)現(xiàn),隨著氧氣濃度的升高,這些HC的生成量不斷降低。在研究NO的生成量時發(fā)現(xiàn),隨著氧氣濃度的升高,NO的生成量急劇升高,并且增長幅度和增長速率都越來越大,NO開始生成的時刻也逐漸提前。為了研究噴油正時對NO生成量的影響,設(shè)定了三種不同的噴油持續(xù)期,分別為15°CA、20°CA、25°CA,設(shè)定了三種不同的噴油提前角,分別是3°CA、7°CA、11°CA。通過研究發(fā)現(xiàn),相同富氧濃度的條件下,隨著噴油持續(xù)期的縮短,NO的排放量降低,隨著噴油提前角的減小,NO的排放量降低,因此可以通過改變噴油正時來優(yōu)化NO的排放量。本文在研究富氮進(jìn)氣燃燒的過程中,分別設(shè)置了2種不同的富氮進(jìn)氣濃度,分別為81%和83%。通過研究發(fā)現(xiàn),富氮進(jìn)氣與自然進(jìn)氣相比,富氮進(jìn)氣會導(dǎo)致燃燒室內(nèi)的溫度峰值和壓力峰值下降。同時富氮進(jìn)氣對柴油機(jī)的排放特性也有很大的影響,富氮進(jìn)氣會加劇燃料的不完全燃燒,導(dǎo)致CO和HC的生成量升高。在研究不同轉(zhuǎn)速對CO和HC的生成量的影響時發(fā)現(xiàn),隨著發(fā)動機(jī)轉(zhuǎn)速的降低,CO和HC的生成量均不斷降低。同時還研究了富氮進(jìn)氣對NO排放的影響,由于氮氣的阻燃作用,NO的生成量隨著氮氣濃度的升高而逐漸降低。
[Abstract]:In this paper, the effect of variable component intake on combustion and emission characteristics of diesel engine is studied. This technology can effectively improve the combustion characteristics of diesel engine by changing the concentration of various components in the intake. At the same time, it can reduce the emission of many harmful gases, and can improve a series of problems such as the difficulty of engine ignition, the decline of power performance, the low thermal efficiency, the incomplete combustion and so on. However, the technology is still in the research stage, and there are still many technical problems in practical application. In this paper, the influence of variable component intake on combustion and emission characteristics of diesel engine is studied. It is mainly divided into two parts, one is oxygen-enriched intake combustion, the other is nitrogen-rich intake combustion. In order to achieve the purpose of the study, Chemkin-pro and AVL-Fire are used to carry out the relevant simulation analysis. Firstly, the mechanism of n-heptane chemical reaction is established by using Chemkin-pro. In order to better predict the effect of variable component intake on diesel engine emission characteristics, the mechanism model of no generation is added on the basis of the original chemical reaction mechanism. A new chemical reaction mechanism was established. The geometric model established by Pro/e is imported into AVL-Fire to generate dynamic mesh. During the study of oxygen-enriched intake combustion, four different oxygen-enriched inlet concentrations were set up, which were 2325% and 29%, respectively. The temperature, heat release rate, cumulative heat release rate and pressure were studied in comparison with natural air intake. Change trend of pressure rise rate and other related parameters. It is found that these parameters increase in varying degrees with the increase of inlet oxygen concentration, so the oxygen-enriched intake can effectively increase the dynamic performance of diesel engine in the working process. It is found that the low temperature and hypoxia are the main factors that lead to CO formation, so the oxygen-enriched intake can effectively reduce the emission of CO in diesel engine by studying the effect of oxygen-enriched intake on the emission characteristics of diesel engine. In order to study the effect of oxygen-enriched air intake on HC production, the six main products of Ch _ 3H _ 4 Ch _ 3O _ 3 Ch _ 3O _ 3 Ch _ 2O _ 3 Ch _ 2O _ 2 H _ 2H _ 5 and C3H6 were selected as the most important research objects. Through simulation analysis, it was found that the HC production decreased with the increase of oxygen concentration. When the amount of no was studied, it was found that with the increase of oxygen concentration, the production of no increased sharply, and the increasing amplitude and growth rate of no increased gradually. In order to study the effect of injection timing on no production, three different fuel injection durations were set up, which were 15 擄CA-20 擄CA-25 擄CAand 3 擄CA-7 擄CA11 擄CA. It is found that under the same oxygen enrichment concentration, no emission decreases with the shortening of fuel injection duration and the decrease of fuel injection advance angle. Therefore, no emission can be optimized by changing the injection timing. In this paper, two different concentrations of nitrogen-rich intake are set up, which are 81% and 83% respectively. It is found that compared with natural air intake, nitrogen-rich intake will lead to the decrease of temperature and pressure peak in the combustor. At the same time, nitrogen-rich intake also has a great influence on the emission characteristics of diesel engine. The nitrogen-rich intake will aggravate the incomplete combustion of fuel and lead to the increase of CO and HC production. It is found that with the decrease of engine speed, the amount of CO and HC is decreasing with the decrease of engine speed, and the effect of different rotational speeds on the production of CO and HC is studied. At the same time, the effect of nitrogen-rich intake on no emission was also studied. The amount of no produced decreased with the increase of nitrogen concentration due to the flame retardation of nitrogen.
【學(xué)位授予單位】：吉林大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2016
【分類號】：TK421.2

【參考文獻(xiàn)】

相關(guān)期刊論文 前8條

1 宮長明;彭樂高;張自雷;陳天翔;李棟;;DISI甲醇發(fā)動機(jī)分層稀薄燃燒試驗研究[J];車用發(fā)動機(jī);2014年06期

2 劉剛;周平;任曉江;張恒超;;車輛發(fā)動機(jī)高原增壓措施探討[J];內(nèi)燃機(jī);2011年02期

3 楊菁;;光化學(xué)煙霧的形成機(jī)理及防治措施[J];安陽師范學(xué)院學(xué)報;2007年05期

4 李樹德;水冷發(fā)動機(jī)工程機(jī)械的高原低溫起動改造[J];鐵道工程學(xué)報;2003年04期

5 左承基,李海海,徐天玉,路蘇君;柴油機(jī)富氧燃燒排放特性的試驗研究[J];熱科學(xué)與技術(shù);2003年01期

6 王大興,張欣,劉建華;均質(zhì)壓燃式(HCCI)燃燒的研究[J];內(nèi)燃機(jī)工程;2002年04期

7 劉應(yīng)書,馮俊小,樂愷,李洪利;富氧燃燒對汽油機(jī)性能指標(biāo)的影響[J];工業(yè)加熱;2001年06期

8 沈光林;膜法富氧的應(yīng)用進(jìn)展[J];現(xiàn)代化工;1997年12期

相關(guān)博士學(xué)位論文 前6條

1 張韋;柴油機(jī)富氧燃燒及排放的實驗研究與理論計算[D];天津大學(xué);2010年

2 金英愛;不同進(jìn)氣組分發(fā)動機(jī)燃燒機(jī)理及排放特性研究[D];吉林大學(xué);2009年

3 孫俊;內(nèi)燃機(jī)燃燒模擬理論與應(yīng)用研究[D];武漢理工大學(xué);2008年

4 石秀勇;噴油規(guī)律對柴油機(jī)性能與排放的影響研究[D];山東大學(xué);2007年

5 覃軍;降低柴油機(jī)NO_X排放的SCR系統(tǒng)控制策略研究[D];武漢理工大學(xué);2007年

6 朱昌吉;車用柴油機(jī)電控EGR系統(tǒng)設(shè)計及性能研究[D];吉林大學(xué);2005年

相關(guān)碩士學(xué)位論文 前4條

1 蘇德淵;汽油機(jī)富氧富氮進(jìn)氣的控制與燃燒模擬[D];吉林大學(xué);2013年

2 楊慶剛;柴油機(jī)富氧燃燒機(jī)理與排放性能數(shù)值模擬研究[D];大連理工大學(xué);2012年

3 曲振愛;船艇柴油機(jī)膜法富氧燃燒技術(shù)的研究[D];浙江大學(xué);2012年

4 周鵬;柴油機(jī)燃燒機(jī)理及缸內(nèi)燃燒過程仿真研究[D];哈爾濱工程大學(xué);2012年

，

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