2022年柴油机喷油系统的排放控制技术研究.docx

柴油机喷油系统的排放掌握技术讨论摘要：柴油机净化的关键是如何有效地排除NO 和微粒碳烟的生成量；文章从喷油系统动身，提出了改进排放的五种切实可行的方法，具有明显的现实意义；Abstract: purifying diesel engine is the key to how to effectively eliminate the NO and carbon particles in the smoke generation. Article embarks from the fuel injection system, and puts forward the improved emissions of five kinds of practical methods, has obvious practical significance.关键词：柴油机；排放掌握；措施Key words: diesel engine ； Emission control ； measures柴油机的有害排放取决于柴油机混合气形成及缸内燃烧过程， 而这些归根究竟是由喷油、气流、燃烧系统以及缸内工作特质的配合所打算的；柴油机净化的关键，是如何有效地排除NO 和微粒碳烟的生成量；恰恰这两项排放物的生成规律经常是相互冲突的；因此，任何一个单项措施总有它的负面影响；人们总是在实行某项措施的同时，应用另一项措施来加以补救和平稳；最终，经常是多项措施的综合应用，才使排放性能达到一个新的水平；柴油机是一个多性能、多工况、多因素综合影响的统一体，再加上各种各样的排放净化措施，如何进行优选、折中和综合掌握是一个极为困难和复杂的问题；柴油机的电子掌握和综合治理是有效解决这一问题的正确途径，也是使各种机内净化措施得以充分发挥效用的保证；在全部净化措施中，喷油系统的改进无疑是最为重要的环节；The harmfulemissionsof diesel enginedependson the mixture formationandcombustionprocessin cylinderof dieselengine, which are in the final analysis is by injectionin cylinder, air flow, combustionsystemandworkingcharacteristicsof cooperation. Purification of diesel engine key is how to effectively eliminate theNO and carbonparticlesin the smokegeneration.Just this twoemissions generated rules are often contradictory. Therefore, any single measure always has its negative effects. People are alwaysin a measuresat the same time, applicationof anothersteps toremedythemandbalance.Finally,oftenisacomprehensive application of measures to make emissions performance to a new level.Dieselengineismorethana performanceandworking conditionand factor synthesisinfluencecontinuum,plus various emissionspurificationmeasures,howto carryout optimization, compromise,and integratedcontrolis an extremelydifficultand complexproblem.Diesel engine electronic control and integrated management is the best way to solve this problem, effective alsoallowsvariousinternalpurificationmeasuresto give full play toutility. Of amongall the purificationmeasures,improvethe fuel injection system is undoubtedly the most important link.车用柴油机中常用的机械燃油喷射系统有两大类，直列泵系统和转子安排泵系统；直列泵系统包括直列多缸泵、单体泵和泵喷嘴系统，多用于大、中型车用柴油机上；转子安排泵系统有端面凸轮驱动的 VE 泵系统，和内凸轮驱动的径向对置柱塞系统，多用于轻型客车和柴油轿车的小型高速柴油机上；上述各系统都是应用柱塞往复运动、脉动供油的方式工作；以下是五种掌握柴油机排放的详细措施：Automotivedieselenginethat is commonlyused in mechanical fuel injectionsystem has two types, inline pump system and the distribution of the rotor pump system. Inline pump system including inlinemulti-cylinderpump,singlepumpandthepumpnozzle system,used in largeand medium-sizedvehicledieselengine. Distributionof the rotorpump systemhas end CAMdrivenVE pump system, and the radial opposed piston CAM driven system,more for passenger cars and diesel cars, small high-speed dieselengine.Theabovesystemsareapplicationofplunger reciprocating motion, and pulse oil supply work. Here are five kindsof diesel engine emission control measures:一、推迟喷油提前角降低 NO 排放A, delay the injection advance Angle to reduce NO emissions喷油提前角是喷油始点早于汽缸压缩上止点的角度；柴油机都要求喷油提前，这是由于从喷油到着火有一段滞燃期，为保证明际燃烧放热中心能接近上止点，防止燃烧拖后，经济性下降，所以喷油要提前；单从动力、经济性角度动身，正确提前角随转速上升而增大；随负荷加大而略有增加；车用柴油机由于在宽广的转速范畴内工作，所以有专设的转速自动提前装置来满意此要求；同一工 况，如提前角转变，会使滞燃期转变；一般推迟喷油时，因初期喷油更接近上止点，故缸内压力、温度较高，滞燃期缩短；其结果是滞燃期的预混喷油量削减；当然，如喷油太迟，使滞燃期挪到上止点之后，就缸内压力、温度未必上升；这种情形一般难于遇到；预混燃烧阶段是影响NO 排放最重要的时期；预混油量及混合气量的削减将使速燃期中压力、温度上升程度降低，从而大大削减NO 的排放量；同时，由于压力上升率的下降，噪声也大大降低；因此推迟喷油提前角这一措施，是最早应用的有效降低NO 排放和噪声的计策；推迟喷油，直喷机的NO 大幅下降，而间接喷射式涡流室柴油机的下降幅度就小一些；但是喷油过迟，就燃油消耗率和烟度都会恶化，对 CO 和 HC 也有不利影响；油耗和烟度的恶化是喷油推迟，燃烧跟着推迟以及缓燃期油量增加，燃烧时期也拉长的必定结 果；早期掌握排放的措施不多，为了排放达标，不得不牺牲经济性 能；近期已可通过提高喷射压力等多种方法来综合解决这一问题；Fuel injectionadvanceAngleis injectionstartingpointis earlier than the checkpoint on the cylindercompressionAngle.Dieselengines requireinjectionin advance,becausefrom the oil to the fire for a periodof ignitiondelay period,in orderto ensurethe check point on the actual combustionexothermiccentre close to avoidburningaftertheeconomyfell,soinjectioninadvance. Single from the perspective of power, economy, the best advance Angle increases with rising speed； A slight increase with the loadincreasing. Automotive diesel engine because of working within awide speed range, therefore have set up automatic speed device in advance to meet this requirement. The same working condition, if the advance Angle change, change can make the ignition delayperiod.Generaldelayedinjection,becausetheinitialinjection closer to the top dead center, consequentlyhigher pressureand temperaturein cylinder,shortenthe ignitiondelayperiod.As a result, the ignition delay period of premixedfuel injection quantity is reduced. , of course, if the oil is too late to make on the ignitiondelayperiodto checkpoint,thepressureandtemperaturein cylindermaynotrise.Itisdifficulttoencounteringeneral. Premixedcombustionphase is NO emissionsthe most important period.Less premixed oil and mixed gas will reduce fast-burning mid-termdegreeofpressure,temperaturerise,thereby significantly reducing the NO emissions. At the same time, due to reduced pressurerise rate, noise is greatly reduced.So delayedfuel injection advance Angle the measure, is the earliest application effectively reduce NO emissions and noise countermeasures. Delayed injection, injection machine NO has fallen sharply, and indirect injection type swirl chamber diesel engine decline is smaller. But injection too late, the specific fuel consumption and smoke worsens, is have an adverse effect on COand HC. Fuel consumption and the deterioration of the smoke is injection delay, burning with phase delay and slow burning oil increased, the combustion time is also the inevitable result of thelong. Early few measures to curb emissions, for the sake ofemissionstandardand have to sacrificeeconomicperformance. Have recently can through increaseinjection pressureand so on the many kinds of ways to solve this problem.二、燃油高压喷射降低微粒碳烟排放Second,thehighpressurejetfueltoreducecarbonsmoke emission近年来，提高喷油压力的高压喷射措施，日渐成为直喷式柴油机机内净化的正确手段；而间接喷射式柴油机，由于主要依靠气流进行雾化、混合，所以对喷油压力要求较低；在循环喷油量及喷孔大小和分布不变的情形下，提高喷油压力就是加大喷油速率，它直接产生两方面的成效；In recentyears, increasethe injectionpressureof high pressureinjection measures, is the best means of di diesel engine machine purification. And indirect injection diesel engine, because the mainrely on air flowfor atomizationand mixing,and so on injectionpressure is low. In cycle fuel injection quantity and the size of thesprayholeandundertheconditionofinvariabledistribution, improvethe injectionrate andinjectionpressureis increasedit directly result in two aspects.（一）降低微粒碳烟的排放量a reduce the carbon emissions of smoke particles可以看出，喷油压力增高，就粒径减小，贯穿距加大，雾锥角加大，喷雾区的总体积也跟着加大，再加上紊流的增强，（版权声明：本文转载自论文网在线，版权归原作者全部；）这些都直接促进了燃油与空气的混合；其直接成效是降低了每一时刻浓混合气成分的比例，使生成微粒碳烟的范畴自然缩小；即使不行防止仍有过浓混合气显现，但因粒子小，四周空气 多，也会加快燃烧和氧化速率，使碳烟形成之初就被加速氧化；所以高压喷射必定使微粒碳烟排放降低；大量试验都证明了这一点；As you can see, the injection pressure increased, the particle sizedecreases, and through the distance, spray cone Angle increases,thevolumeof sprayzonestartstoincrease,coupledwiththe increase of the turbulence net of paper of copyright statement: this articlereprintedfromonline,allpeeroriginator. These are directly promoted the fuel and air mixture. Its direct effect is to reduce the proportion of the amount of the every momentrich mixture,and makes the generatedparticlescarbon smoke natural narrowed down. Even inevitable there are still a rich mixture,but becauseof the small particles,the surroundingair, also can acceleratecombustionand oxidationrate, make carbon smoke form is at the beginning of accelerated oxidation. Thereforehigh-pressure jet will reduce particulate carbon smoke emission. A large number of tests have confirmed that.（二）降低燃油消耗率2 reduce the specific fuel consumption喷油速率增大必定缩短喷油时期，使燃烧加速，使燃烧放热更 集中于上止点邻近，从而降低了燃油消耗率；大量试验结果也证明 了这一点；以上高压喷射降低烟度和油耗的优点，恰恰补偿了推迟 喷油所带来的缺点；反过来，高压喷射不行防止地使混合气快速变 稀，燃烧加速，温度上升，从而NO 排放必定有所增大；这一弱点又会被推迟喷油，降低的 NO 功效所补偿；应当记住，高压喷射并没有过大减弱推迟喷油，减小滞燃期喷油量所带来的改善NO 排放的显著成效；因此如两种措施同时应用，进行合理调配后，NO和微粒碳烟排放都会同时降低；目前，两种措施并用是最常见的手段； 三、喷油率掌握技术Injectionrateincreaseswillshortentheinjectionperiod,theburningspeed,the combustionheat releasemore concentrated near the top dead center, reducingthe fuel consumptionrate. A large number of experimental results also confirm this. Above thelowersmokeandfuelconsumption,theadvantagesofhigh pressure jet just makes up for the delay the disadvantages broughtby the injection. High-pressure jet inevitably, in turn, make the mixture quickly dilute and combustion speed, temperature rise, and NO emission will increase somewhat. This weakness would beput off oil, reduce the availability of nitric oxide NO, made up for efficacy. Too much should keep in mind that high-pressure jet doesnot weakenthe delay sprayoil, reducethe ignitiondelay period improvedfuel injectionquantity brings NO emissionssignificantly effect. So if two measuresappliedat the same time, reasonable allocate,NOandsmokeparticlesof carbonemissionswillbe reducedat the sametime. At present,and is the most common means of two kinds of measures. Third, fuel injection rate control technology广义的喷油率掌握，指的是喷油规律掌握，应包括定时（喷油提前角）掌握、喷油期长短掌握和喷油率大小（喷油率曲线形状） 掌握；此处撇开喷油定时，单指在定时和循环油量不变时，喷油长短和喷油率形状的掌握；喷油率是除混合气形成因素外，对燃烧过程又一重大的影响因素；当然，喷油率本身也和混合气形成是密不可分的；可以设想，如喷油时期掌握得很长，即使大幅度提高喷油 压力，也无法缩短放热和燃烧时间；又如，初期喷油量很大，即使 推迟喷油，也无法把 NO 和噪声降得很低；反过来，如能把初期喷油量掌握得很小，就是不推迟喷油，也可达到同样成效；可见，喷 油率如能掌握，将极富成果，因此，成为近年来喷油系统讨论、开 发的热门课题；General fuel injection rate control, refers to the fuel injection law control, and shall include timing, fuel injection advance Angle, injection period length control size and injection rate control fuel injection rate curve shape. Here apart from fuel injection timing, single refers to the timing and at constant circulation of oil, fuel injection duration and injection rate shape control. The injection rate is in addition to the mixture to form factors, another major influence factors of the combustion process. The fuel injection rate,of course, itself and mixture formation is inseparable. Can imagine,such as fuel injection control during the period of very long, even iftheincreaseinjectionpressure,canshortentheheatingand burning time ； As another example, initial fuel injection quantity is very big, even if delayedinjection,also can't get NO and noise drop too low. If you can, in turn, controlthe initial fuel injection quantityisverysmall,justdon'tdelaytheinjection,alsocan achievethe same effect. Visible, if can control, fuel injectionratewillbeextremelyrichachievement,therefore,inrecentyears become a hot topic of research, development, fuel injection system.抱负的喷油率图形可分为三个时期，即喷油初期，喷油中期， 喷油后期；抱负的喷油率图形一般公认为：初期要求喷油率低，喷 油量少，以降低 NO 和噪声；中期要求短而高的喷油率段，以提高喷油压力，缩短缓燃期，促进混合气（下接第182 页） 上接第 173页 形成，使微粒碳烟排放和耗油率降低；后期就要求快速终止喷油，以削减后燃油量和促进碳烟氧化；喷油中期的掌握，一般是通过提高喷油压力来实现；掌握初期喷油率的主要技术有：机械式预喷射装置，双弹簧喷油器，电控喷油系统掌握预喷射；大量试验结果说明，要获得良好的成效，预喷射油量、主预喷射的间隔角度以及油量和时间的掌握精度都有严格的规定；只有电控高压共轨式喷油系统才能全面满意这些要求；末期喷油段要求快速关闭，可以通过减轻油嘴往复运动部分（针阀、推杆、弹簧）的质量，加速针阀关闭速度来掌握；这就是已广泛推广使用的低惯量喷油器和P 型 J型小型喷油器；此外，增大针阀开启压力也可加速针阀落座；但是真正有效掌握的手段，仍是使用电磁阀的电控喷射系统的快速断 油；Graphicsidealinjectionrate can bedividedintothreeperiods, namely early injection, fuel injection, in the middle of the injection period. Graphics ideal injection rate generally recognized as: initial requestlow injectionrate,injectionquantityis little,in ordertoreduce NO and noise ； Medium-term required short and high injection rate period, in order to improve the injection pressure, shorten the slow-burning period, promote mixture next pick p. 182on page 173 is formed, reduce particulate carbon smoke emission and fuel consumption rate ； Late to a swift end to injection to reduce the fuel quantity and promote carbon smokeafteroxidation.Injectionin themiddleof control,generalis to achieveby increasinginjectionpressure.Controlof fuel injection ratein the early yearsof the main techniquesare:mechanical spraying device, double spring injectors, injection electronic controlfuel injection system control. A large number of experimental results show that, to obtain good results, pilot injection, main injection oil interval Angle and oil control precision and time, thereis strict rules. Only electronically controlled high pressure commonrail fuel injectionsystem can fully meet theserequirements.Late injectionrequirementsquicklyshutdown,canreducethe reciprocating motion of nozzle part needle valve, push rod, spring quality, accelerate the speed of needle valve closed to control. Thisis already widely used the low inertia of injector and small injectortype P J type. In addition, increase the needle valve opening pressure also can accelerate the needle valve seat. But truly effective control means, still is the use of electromagnetic valve ofthe electronic control injection system of rapid cut-off.四、小直径、多喷孔加速雾化混合More than four, small diameter, nozzle hole accelerated atomized mixture在喷油速率不变情形下 ,可以通过减小喷孔直径，增加喷孔数目，使喷注在燃烧室内分布更匀称、更布满的方法，来加速油、气混合，获得较好排放成效；六孔喷嘴与四孔喷嘴相比，六孔的总混合容积加大，单个喷注较窄，芯部浓混合气易于扩散、燃烧；这些都与加大喷油压力的成效相像；增加喷孔数后，可以降低对气流的要求；涡流比可以减小，从而改善了燃油经济性；如喷孔过多，由于贯穿不足和相邻喷注的干扰，反有不利成效；Undertheconditionofconstantinjectionrate,canreducethe nozzlehole diameter,increasethe numberof nozzle,jet in the combustionchamberdistributionmoreuniform,morefullof methods, to speed up the oil, gas mixture, obtain good effect. Six, comparedwithfourholeson thenozzleholenozzleholetotal mixed volume increase, a single injection is relatively narrow, corerich mixture is easy to spread, burning. These are similar to increase the effect of injection pressure. Increase injection hole number, can reduce the requirement for air flow. Eddy current ratiocan be reduced, so as to improve the fuel economy. If the nozzle is overmuch, caused by a lack of penetrating and adjacent jetinterference, have an adverse effect.双语对比查看五喷油系统的其他净化措施5. Other purification measures of fuel injection system目前已广泛应用的降低HC 排放的措施就是减小孔式喷嘴压力室容积或采纳无压力室式喷油嘴；大量使用试验说明，柴油机长期 运行后，其有害排放值基本没有增加；这同汽油机长期使用后，有 害排放量增幅较大的情形是不一样的；假如柴油机使用过程中，排 放性能突然恶化，就相当部分是喷油系统不能保持正常工作状态所 致；当使用中发觉过量冒烟时，第一要检查各个喷油器开启压力是 否明显下降，或喷雾状态是否良好；有条件时，应在油泵试验台上 测试循环油量是否超过所规定之值以及各缸油量是否严峻不匀称； 造成循环油量不匀称及超标的缘由是许多的，如柱塞副的磨损，出 油阀密封性变差，油孔的堵塞等等；应查明缘由，该更换的更换， 或进行清洗；但应留意，油泵及调速器一经拆动，必（版权声明： 本文转载自论文网在线 ，版权归原作者全部；）须重新在台架上调整；假如冒烟现象很难解决，无法达标上 路，可以适当降负荷运行；这样做会牺牲一些动力性能；西方国家为了达标，也会实行同样措施；如德国大众汽车公司推出的TDI1 ；9L 轿车增压直喷机，无排放限制（赛车）时，标定功率达125K