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1、第6期內(nèi)燃機(jī)No.6墊!!竺!塑—————————』竺些竺竺塵竺些二—————————』:些不同工況下對(duì)OPOC柴油機(jī)全周期循環(huán)的仿真分析劉若凡,續(xù)彥芳,許俊峰,郭勇,李樹宇(中北大學(xué)機(jī)械與動(dòng)力工程學(xué)院,山西太原030051)摘要:利用三維分析軟件AVL—FIRE對(duì)OPOC發(fā)動(dòng)機(jī)在不同工況下的二沖程全周期三維瞬態(tài)上作循環(huán)L自由排氣、掃氣、過后充氣、壓縮、燃燒和膨脹做功)進(jìn)行分析,研究了全周期循環(huán)過程中不同轉(zhuǎn)速下的掃氣質(zhì)量、氣體流動(dòng)、混合氣形成與燃燒以及排放物的生成等瞬態(tài)變化規(guī)律。分析表明,隨著轉(zhuǎn)速的升高,掃氣效率和給氣比逐漸降低,捕獲率增加,最大氣缸壓力不斷減小,缸內(nèi)平均溫度
2、在換氣過程和膨脹過程中隨轉(zhuǎn)速的升高而升高,在燃燒過程中隨轉(zhuǎn)速變化不大。NO的生成量隨著轉(zhuǎn)速的升高而降低,Soot的生成峰值也隨著轉(zhuǎn)速的升高而降低,但是由于受到氧化作用,Soot的最終生成量隨轉(zhuǎn)速的升高而升高。關(guān)鍵詞:對(duì)置活塞;對(duì)置氣缸發(fā)動(dòng)機(jī);循環(huán);掃氣;燃燒;排放中圖分類號(hào):TK421文獻(xiàn)標(biāo)識(shí)碼:A文章編號(hào):1000—6494(2016)06—0027一04SimulationandAnalysisofFullCycleofOPOCDieselEngineunderDifferentWorkingConditionsLIURuofan,XUYanfang,XUJunfeng,
3、GUOYong,LIShuyu(NorthUniversityofChina,Taiyuan030051)Abstract:Byusingthree——dimensionalnumeficMsimulationsoftwareAVL——FIREtosimulatethetwostrokethree——dimensionaltransientcycle(includingfreeexhaust,scavenging,afterinflation,compression,combustionandexpansion)oftheOPOCengineindifferentworkin
4、gconditions,thispaperinvestigatesthetransientchanginglawofthecycleunderdifferentspeed,includingsweepgasq眥aty,gasflow,mixtureformationandcombustionandemissionsgeneration.AnMysisshowed:withtheincreaseoftherotatingspeed,thescavengingefficiencyandthedeliveryratiodecreasedgradually,thecapturerat
5、eincreased,andthemaximumcylinderpressuredecreased.Theaveragetemperatureinthecylinderincreaseswiththeincreaseoftherotatingspeedintheprocessofsweepinggasandexpansion,whileitdoesnotvarywiththespeedintheprocessofcombustion.ThemeanNOmassfractiondecreaseswiththeincreaseofrotationalspeed,themaximu
6、mmassfractionofSootalsodecreaseswiththeincreaseofrotationalspeed.Butduetooxidation,thefinalmeanSootmassfractionincreaseswiththeincreaseofrotationalspeed.Keywords:opposedpiston;opposedcylinderengine;workingcycle;sweepgas;combustion;emission0前言雙對(duì)置二沖程柴油機(jī)在結(jié)構(gòu)上是對(duì)置活塞對(duì)置汽缸發(fā)動(dòng)機(jī)(opposedpistonandopposed
7、cylinderengine),所以又簡(jiǎn)稱OPOC發(fā)動(dòng)機(jī),見圖1,OPOC發(fā)動(dòng)機(jī)有兩個(gè)水平對(duì)置的氣缸,曲軸位于兩個(gè)氣缸中間,每個(gè)氣缸中有兩個(gè)向相反方向運(yùn)動(dòng)的活塞。其結(jié)作者簡(jiǎn)介:劉若凡(1992一),女,河南人,碩士,主要從事發(fā)動(dòng)機(jī)缸內(nèi)燃燒仿真模擬。收稿日期:2016—06—01構(gòu)與傳統(tǒng)的四沖程發(fā)動(dòng)機(jī)相比,消除了傳統(tǒng)發(fā)動(dòng)機(jī)的氣缸蓋和氣門控制組件,使其具有結(jié)構(gòu)緊湊,質(zhì)量輕,振動(dòng)小,噪聲小,油耗低,功率密度大等優(yōu)點(diǎn),同時(shí)發(fā)動(dòng)機(jī)還能夠?qū)崿F(xiàn)自我平衡。國(guó)外針對(duì)對(duì)置二沖程柴油機(jī)的研究工作已廣泛展開“叼,其中以FEV和