發(fā)布時(shí)間：2018-01-09 02:02

  本文關(guān)鍵詞：兩種技術(shù)路線的重型車整車載荷對(duì)排放的影響研究　出處：《江蘇大學(xué)》2017年碩士論文　論文類型：學(xué)位論文

  更多相關(guān)文章： 國(guó)Ⅵ 重型車 整車排放 載荷 EGR

【摘要】：本文以兩輛符合國(guó)Ⅵ排放水平的重型車整車為研究對(duì)象,開(kāi)展國(guó)Ⅵ重型車整車排放實(shí)驗(yàn)研究。實(shí)驗(yàn)在重型底盤測(cè)功機(jī)上進(jìn)行,選取0%、25%、50%、75%和100%整車載荷為不同工況點(diǎn),運(yùn)行C-WTVC循環(huán)。兩輛樣車分別采用DOC+SCR+DPF+EGR和DOC+SCR+DPF的后處理技術(shù)路線,實(shí)驗(yàn)前首先對(duì)兩輛樣車進(jìn)行重復(fù)性排放驗(yàn)證,確定兩輛樣車的數(shù)據(jù)一致性與工況跟蹤性是否符合實(shí)驗(yàn)要求,并對(duì)兩輛樣車進(jìn)行不同載荷下的阻力參數(shù)分析。將氮氧分析儀與CVS全流稀釋采樣系統(tǒng)的采樣設(shè)備并聯(lián)安裝,構(gòu)建了符合本研究要求的實(shí)驗(yàn)系統(tǒng)。實(shí)驗(yàn)獲得了不同整車載荷工況下的NOx、HC、CO等氣體污染物的排放數(shù)據(jù),測(cè)量了整車顆粒物質(zhì)量及數(shù)量排放情況,利用氮氧分析儀對(duì)NOx排放進(jìn)行了細(xì)化分析并對(duì)NH3的排放進(jìn)行了測(cè)量,同時(shí)采集了排氣溫度、NOx原機(jī)排放、EGR流量等車輛基本運(yùn)行參數(shù)。通過(guò)數(shù)據(jù)處理,分析了國(guó)Ⅵ重型車在不同載荷工況下NOx和顆粒物的排放規(guī)律,以及NOx主要組成成分NO、NO2和N2O的排放規(guī)律。探討了車輛氣體和顆粒污染物排放受載荷變化的影響,以及不同技術(shù)路線車輛排放受載荷影響差異性。全文工作內(nèi)容及所得的主要結(jié)論概括如下:(1)通過(guò)兩輛樣車的氣體污染物排放受載荷變化的影響研究發(fā)現(xiàn),對(duì)于達(dá)到國(guó)Ⅵ排放標(biāo)準(zhǔn)的重型車整車,兩種后處理技術(shù)路線重型車的HC和CO排放均不受載荷影響。未采用EGR技術(shù)的車輛,其NOx排放會(huì)隨著載荷的增大而降低;采用EGR技術(shù)的車輛,NOx排放會(huì)隨著載荷的增大先升高后降低。(2)通過(guò)對(duì)NOx排放規(guī)律研究發(fā)現(xiàn),在C-WTVC循環(huán)實(shí)驗(yàn)中,兩種技術(shù)路線的重型車,其NOx排放均主要由循環(huán)起始前半段提供。在循環(huán)前500~800s,NOx排放占整個(gè)循環(huán)的80%以上,且這一比例會(huì)隨著載荷的增大而增加。載荷通過(guò)影響排氣溫度,改變后處理SCR催化器工作時(shí)間點(diǎn)來(lái)影響排放。采用不同技術(shù)路線車輛的排氣溫度受載荷影響不同,采用EGR技術(shù)的車輛其排溫上升快,但排氣溫度隨載荷變化的波動(dòng)范圍小;未采用EGR技術(shù)的車輛其排溫上升慢,但排氣溫度隨載荷變化的波動(dòng)范圍大。綜合來(lái)看,未采用EGR技術(shù)的車輛,其NOx排放對(duì)載荷變化的影響比較敏感,較易受到載荷變化的影響;采用EGR技術(shù)的車輛,其NOx排放受載荷變化影響相對(duì)較小。(3)通過(guò)對(duì)NOx原機(jī)排放研究發(fā)現(xiàn),在同載荷工況下,NOx原機(jī)排放對(duì)后NOx的排放影響較大。在循環(huán)起始前幾百秒,SCR催化器未開(kāi)始高效轉(zhuǎn)化,此時(shí)原機(jī)排放水平將直接影響整個(gè)循環(huán)的排放水平。未采用EGR技術(shù)的車輛,其NOx原機(jī)排放隨著載荷的增大而升高;采用EGR技術(shù)的車輛,其NOx原機(jī)排放隨著載荷的增大先升高后保持平穩(wěn)。在不同載荷工況下,兩技術(shù)路線的車輛,其NOx排放均主要受排氣溫度變化的影響,不受NOx原機(jī)排放隨載荷變化趨勢(shì)的影響。(4)對(duì)NOx進(jìn)一步分析,以及對(duì)NO、NO2和N2O的排放規(guī)律進(jìn)行研究發(fā)現(xiàn),兩種技術(shù)路線的重型車,NOx各組成成分的排放最大值均會(huì)隨著載荷的增大而升高,隨著載荷的增大更容易出現(xiàn)極端排放情況。對(duì)于未采用EGR技術(shù)的國(guó)Ⅵ重型車,其N2O排放量較低,N02排放略高;NO、NO2和N2O的排放都會(huì)隨著載荷的升高而降低,三者都主要生成于循環(huán)的前半段,與NOx總量的排放趨勢(shì)一致。采用EGR技術(shù)的國(guó)Ⅵ重型車,其N2O排放量較高,NO2排放量極低,且N2O的排放趨勢(shì)與EGR流量具有對(duì)應(yīng)一致關(guān)系。其中NO和NO2主要產(chǎn)生于循環(huán)的前半段,N2O主要產(chǎn)生于循環(huán)的后半段。(5)通過(guò)對(duì)顆粒物排放規(guī)律和受載荷變化影響研究發(fā)現(xiàn),未采用EGR技術(shù)的車輛其顆粒物排放主要集中在C-WTVC循環(huán)開(kāi)始和末尾位置;采用EGR技術(shù)的車輛,其顆粒物排放由整個(gè)循環(huán)提供。相對(duì)于未采用EGR技術(shù)的車輛,其顆粒物排放極端情況較少,在整個(gè)循環(huán)內(nèi)呈平穩(wěn)波動(dòng)狀態(tài),顆粒物排放值范圍較小,排放比較穩(wěn)定,受車輛行駛工況影響較小。未采用EGR技術(shù)的車輛,其顆粒物排放隨著整車載荷的變化呈逐漸下降趨勢(shì)。采用EGR技術(shù)的車輛,其顆粒物排放隨著增和的增加先降低后升高。究其原因,低載荷時(shí),少量的EGR流量會(huì)使燃燒持續(xù)期變長(zhǎng),延長(zhǎng)顆粒物的氧化時(shí)間。隨著整車載荷的增加,EGR流量逐漸增加,會(huì)導(dǎo)致氣缸內(nèi)氧含量減少,燃燒情況變差,降低缸內(nèi)溫度,從而降低顆粒物的氧化速率。
[Abstract]:In this paper, two vehicles comply with the level of the heavy vehicle emission as the research object, research on vehicle emission experiment in heavy vehicles. In experiment VI heavy chassis dynamometer, select 0%, 25%, 50%, 75% and 100% of vehicle load for different operating points, running C-WTVC. Two prototypes were used to DOC+SCR+DPF+EGR DOC+SCR+DPF and postprocessing techniques, the experiment before the first of two prototypes of repetitive discharge verification, determine the two prototypes of the data consistency and condition tracking whether meet the requirements, and the two cars were analyzed under different load resistance parameters. The nitrogen oxygen analyzer and CVS full flow dilution sampling system sampling equipment installed in parallel, built in line with the experimental requirements of the system. The experiment obtains different vehicle load conditions NOx, HC, CO and other gas pollutant emissions data, vehicle particulate matter measurement The amount and quantity of emissions, emissions of NOx and makes a detailed analysis on the NH3 emissions were measured by nitrogen oxygen analyzer, collected at the same time the exhaust gas temperature, NOx engine emissions, the basic operation parameters of EGR traffic vehicles. Through data processing, analysis of the emissions of heavy vehicles in China VI different load conditions NOx and the particles, as well as NOx main component of NO, emission of NO2 and N2O. To investigate the effect of vehicle gas and particle emission by the change of load, and the different technical route of vehicle emission load effect difference. The main conclusions and the contents are summarized as follows: (1) the effect of gas two vehicle emission load changes, to reach the discharge standard of heavy vehicle VI, two kinds of postprocessing technique route of heavy-duty vehicle HC and CO emissions were not affected by the load impact. Without using the EG R technology of the vehicle, the NOx emission will decrease with the increase of load; using the technology of EGR vehicles, NOx emissions with the increase of the load is increased first and then decreased. (2) through the research of emission of NOx found in the C-WTVC cycle experiment, heavy truck two techniques, the NOx emissions were mainly by the first half cycle starting. 500~800s in circulation, NOx emissions accounted for more than 80% of the whole cycle, and this ratio will increase with the increase of load. The load through the influence of exhaust gas temperature, SCR catalytic converter working time points after changing to influence emissions. Using different technical route of the vehicle exhaust temperature load effect of different, using EGR technology the vehicle exhaust temperature rising fast, but the exhaust temperature fluctuation range with the change of load; EGR technology with its vehicle exhaust temperature rises slowly, but the exhaust temperature fluctuation range with load change. To comprehensive See, EGR did not use the vehicle, the NOx emissions impact on the change of load sensitive effects are more susceptible to the load change; using EGR technology of the vehicle, the NOx emission load change is relatively small. (3) found through the study of NOx engine emissions at the same loading condition, the original NOx the effects of NOx emissions after the engine emissions greatly. In the cycle before the initiation of hundreds of seconds, SCR catalyst has not started high transformation at this time of the original engine emission level will directly affect the entire cycle of emission levels. EGR technology is not used in the original diesel vehicles, NOx increased with the increase of the load; using the technology of EGR vehicles the original NOx engine emission with the increase of the load increased first and then remained stable. Under different load conditions, the two technical route of the vehicle, the NOx emissions were mainly affected by the variation of the exhaust temperature, not by NOx original diesel effect changing with the load (4) of the trend. NOx further analysis, as well as the NO, found that the emission of NO2 and N2O, two kinds of technology of heavy vehicle emissions, maximum value of the components of NOx are increased with the increase of the load, with the increase of the load more prone to extreme emissions. For not using EGR technology in heavy VI the car, the lower N2O emissions, N02 emissions slightly higher; NO, NO2 and N2O emissions will be reduced as the load increases, the three are mainly generated in the first half of the cycle, consistent with the trend of the total NOx emissions. Using EGR technology of VI heavy vehicles, the higher N2O emissions NO2, extremely low emissions, emission trends and EGR flow and N2O is corresponding to the consistent relationship. The main NO and NO2 produced in the first half of the cycle, N2O is mainly produced in the second half cycle. (5) by the law of the emissions of particulate matter and the effect of load change, not by EGR The vehicle the particulate emission is mainly concentrated in the C-WTVC loop start and end position; using EGR technology of the vehicle, the particulate emission provided by the whole cycle. Compared with EGR technology without the use of the vehicle, the less extreme particulate emissions, a steady state in the whole cycle fluctuations within the range of small particle emissions emissions, is relatively stable, the vehicle driving conditions affected. EGR technology is not used in the vehicle, the particulate emission change with the vehicle load decreased gradually. The EGR technology of the vehicle, the particulate emission increases with increasing and decreased firstly and then increased. The reason of low load, a small amount of EGR traffic the combustion duration becomes longer, the oxidation time of particles. With the increase of vehicle load, EGR traffic has increased, will lead to a reduction in the oxygen content of the cylinder combustion variation, reduce the temperature in cylinder, Thus the oxidation rate of particles is reduced.

【學(xué)位授予單位】：江蘇大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：X734.2;U467.48

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本文編號(hào)：1399524