CN101482066A - 用于点火液喷射器的检验方法 - Google Patents

用于点火液喷射器的检验方法 Download PDF

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CN101482066A
CN101482066A CNA2009100029066A CN200910002906A CN101482066A CN 101482066 A CN101482066 A CN 101482066A CN A2009100029066 A CNA2009100029066 A CN A2009100029066A CN 200910002906 A CN200910002906 A CN 200910002906A CN 101482066 A CN101482066 A CN 101482066A
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fluid injector
ignition fluid
inspection
multifuel engine
firing chamber
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CN101482066B (zh
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N·博克霍夫
A·哈南坎普
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MAN Energy Solutions SE
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MAN Diesel SE
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Abstract

本发明涉及用于点火液喷射器的检验方法，其中，在相同负荷的运行状态中改变点火液喷射器的喷射持续时间。由此有更多或更少的点火液到达气缸的燃烧室，从而相关气缸的排气温度升高或降低。这实现了在液体燃料运行状态期间识别出非正常工作的点火液喷射器。

Description

用于点火液喷射器的检验方法
技术领域
本发明涉及一种用于多燃料发动机点火液喷射器的检验方法，该发动机具有用于有选择地输送液体和气体燃料到燃烧室的输送装置、至少一个用于输送点火液的点火液喷射器、以及用于检测排气温度的测量装置和用于对经测量装置测得的排气温度进行评估的评估装置。
背景技术
当多燃料发动机在燃气运行状态下工作时，燃烧室内通常稀薄的燃气空气混合物通过少量点火液的点火能量点燃。点火液通过适当的输送系统借助点火液喷射器例如在活塞式发动机的活塞快要到达上死点前被导入燃烧室。
借助喷射器将点火液输送到活塞式发动机燃烧室中的公知系统使得喷射过程几乎可以任意构建。所以通过喷射器可以自由选择喷射开始和喷射结束以及点火液的体积流量。此外，多燃料发送机大多配设有发动机电子控制器，它们持续地检测发动机工作数据、例如燃料和排出气体的温度、功率值、燃烧参数、转速、压力或类似物。
由燃烧副产品或点火液输送中的未知错误造成的喷射器的损坏或堵塞会引起点火液喷射故障。在燃气运行状态下这会导致相关气缸内的燃烧中止。这一方面造成了发动机的功率下降，另一方面使得未燃烧的燃气空气混合物到达排气设备，在不利的局部边界条件下甚至会在那里引起爆炸。因此在燃气运行状态下应当避免燃烧中止。所以如果能在转换到燃气运行状态前就能检查点火液喷射的运行能力，就会很有利。
在多燃料发动机转换到燃气运行状态前就已经在之前的液体燃料运行状态期间对点火液喷射器进行检验是迄今没有实现的。点火液喷射器的故障至今只有基于发动机在燃气运行状态下功率的下降和运转平稳性的降低或基于排出气体中燃气的含量来识别。受损或堵塞的点火液喷射器的定位至今只能以直观检测的形式或基于单个气缸的功率检测或运行情况实行。
发明内容
因此本发明所要解决的技术问题是，提供一种用于点火液喷射器的检验方法，该方法实现了在液体燃料运行状态期间就已对多燃料发动机点火液喷射器进行功能检验。
按本发明，该技术问题通过按权利要求1所述的方法解决。从属权利要求的内容则是有利的改型。
本发明的方法包括以下步骤：
a)让多燃料发动机在液体燃料运行状态下运行，其中至少一个点火液喷射器将点火液喷入到多燃料发动机气缸的燃烧室中，
b)改变一个或多个点火液喷射器的喷射持续时间和/或喷射体积，以及
c)评估由测量装置在变动期间测得的排气温度的值。
本发明的方法适用于可用各种液体及气体燃料工作的多燃料发动机。其中液体燃料优选考虑使用十六烷值大于30的、可以让发动机按照柴油机原理运行的易燃燃料。此外，可燃性较小的即十六烷值小于30的液体燃料也适用，它们需要附加装置例如火花塞来点燃。
适合使用本发明方法的多燃料发动机设计为，它们的运行方式可从用液体燃料运行转换为用一种优选易燃的稀薄的燃料空气混合物运行，该燃料空气混合物优选具有气体燃料。此外，就气体燃料而言，该方法同样可应用于用来点燃稀薄的液体燃料空气混合物的点火液喷射器。可使用例如天然气、液化气、木炭气、生物气、填埋气、沼气或氢气作为这类多燃料发动机的燃烧气体。
在燃气运行状态或稀薄混合物运行状态下输送到燃烧室的稀薄燃气空气混合物通常包含明显的过剩空气，因此为了进行外源点火将点火液喷入燃烧室，它的点火能量点燃燃气空气混合物。通常使用适用于此目的的液体燃料作为点火液，它也优选用在多燃料发动机的液体燃料运行状态下。
适合实行本发明检验方法的多燃料发动机具有用于将液体燃料输送到第一燃烧室中的第一输送装置。其中，多燃料发动机的气缸可具有一个或多个燃烧室。下文将气缸的主燃烧室称为第一燃烧室。输送装置也可适用于输送多种不同的液体燃料。第一输送装置优选具有泵送装置、燃料管道以及将燃料直接送入到多燃料发动机燃烧室中的喷射装置或用于形成和输送燃料空气混合物的装置，后者在混合物形成后才将液体燃料送入到燃烧室中。
这种多燃料发动机还具有用于将气体燃料输送到发动机燃烧室中的第二输送装置，该装置优选设计为，使得优选稀薄的燃气空气混合物在输送燃烧室之前就已形成。
此外，该多燃料发动机还具有用于将点火液输送到发动机燃烧室中的第三输送装置。该第三输送装置优选针对多燃料发动机的每个气缸都具有一个或多个点火液喷射器。其中点火液喷射器可设置为使点火液直接喷射到多燃料发动机气缸的第一燃烧室内。点火液喷射器当然也可设置在第二燃烧室内，例如设置在所谓的预燃室内。点火液在燃烧室中自动点燃或借助适当的点火装置点燃。如果点火液喷射器设置在气缸的第二燃烧室内，那么它就有一个或多个到第一燃烧室的连接装置，点火能量通过该连接装置从第二燃烧室传递至第一燃烧室，从而点燃位于那里的燃气空气混合物。根据燃烧室的构造，第二燃烧室内也可设置多个点火液喷射器，此外也可让多个第二燃烧室与气缸的第一燃烧室相连。点火液喷射器优选在液体燃料运行状态和气体燃料运行状态下都向气缸输送点火液，以便避免喷射器发生堵塞。该方法也同样适用于设计为与第一输送装置的喷射器集成的点火液喷射器，这种点火液喷射器的喷射可与第一输送装置的喷射功能无关地得到控制。
此外，适用于本发明检验方法的多燃料发动机还具有优选作为发动机控制器零件的测量装置，该测量装置检测多燃料发动机的排气温度。该测量装置优选检测多燃料发动机的每个单独气缸的排气温度。此外，为了实施该方法还设置了评估装置以用于对测量装置测得的排气温度值进行评估。测量装置和评估装置在此优选设计为，使得在检验过程期间排气温度的短暂变化也能被检测和评估。排气温度的变化优选地在少数几个活塞冲程后就可确定。
在实施本发明的方法时，发动机在液体燃料运行状态下运行。如上所述，待检验的点火液喷射器优选也在液体燃料运行状态下激活。检验方法优选在多燃料发动机处于低负荷或部分负荷的情况下运行时实施，优选在5至25％负荷的范围内实施。在这一范围内利用本发明的检验方法能获得特别可靠的结果。
按照本发明的一种实施例，在以尽可能不变的负荷运行时，点火液喷射器的喷射持续时间在检验过程中改变。在喷射持续时间延长的情况下，体积流量不变时，会有更多的点火液通过点火液喷射器到达气缸的第一燃烧室或视发动机构造而定到达第二燃烧室，相关气缸的排气温度由此升高。
以同样方式可缩短点火液喷射器的喷射持续时间，因此只有较少量的点火液到达燃烧室，从而引起排气温度的下降。
在此可能的是，当喷射延长时，将喷射开始提前和/或将喷射结束延后。相反，当喷射持续时间缩短时，将喷射开始延后和/或将喷射结束提前。
以同样的方式可以让点火液的喷射体积借助通过喷射器的体积流量的改变而发生变化，以便在液体燃料运行状态下也能向多燃料发动机的燃烧室输送更多或更少的点火液，这同样会使气缸的排气温度升高或下降。
在本发明方法的一种优选构成方案中，经检验的喷射器的喷射持续时间按预定的检验周期变化，其中，喷射例如从点火液喷射器的最小喷射持续时间上升至点火液喷射器的最大喷射持续时间。对于最大喷射持续时间而言，当点火液喷射器正常运行时，排气温度上升超过所属负荷的平均值，对于最小喷射持续时间而言，排气温度下降为低于该负荷的平均值。
当点火液喷射器由于故障而向燃烧室输送过多、过少或不输送点火液时，测量装置就会检测到多燃料发动机上排气温度过强、过弱的变化或无变化。因而在激活多燃料发动机的燃气运行状态前就能检验点火液喷射器的运行能力。
如果在一个气缸内设有多个点火液喷射器，那么优选依次对单个点火液喷射器进行功能测试。当借助设置在多燃料发动机上的测量装置不检测单个气缸的排气温度、而是只检测多燃料发动机多个或所有气缸的排气温度时优选以相同的方式进行。
评估装置用于评估由测量装置检测到的排气温度，并优选将测得的测量值配于已检验的点火液喷射器，从而对未正常运行的点火液喷射器定位。假如由于点火液喷射器故障而会出现燃烧错误甚至中断，那么通过本发明检验方法获得的评估结果就能避免多燃料发动机转换到燃气运行状态。
此外，通过基于评估结果获得的对按规定或不按规定运行的相关点火液喷射器的了解，例如也可以只让多燃料发动机的单个气缸不被加载燃气。假如一个气缸内设有多个点火液喷射器，那么其它点火液喷射器的喷射持续时间和/或喷射体积就会加大。最后，检验结果对所需维修措施的计划和实施形成支持。
附图说明
下面结合附图对本发明的其它优点、特征和应用可能性加以说明。图中：
图1示出了适合使用本发明检验方法的多燃料发动机；
图2示出了在点火液喷射器工作的情况下，气缸的排气温度在一个示例性检验周期内的示例性时间变化曲线；以及
图3示出了在点火液喷射器停止工作的情况下，气缸的排气温度在一个检验周期内的时间变化曲线。
具体实施方式
图1示出了适合使用本发明检验方法的多燃料发动机的各个元件。该发动机具有气缸2，气缸2具有以已知方式设计的气缸盖3。由连杆5引导的活塞4在气缸2内运动。
气缸盖3内固定着燃料喷射器6，液体燃料可通过它经由燃料管道7从燃料泵8直接喷入第一燃烧室9。燃料喷射器6、燃料管道7以及燃料泵8是用于将液体燃料输送到第一燃烧室9中的第一输送装置10的元件。在气缸盖3内在燃料喷射器6附近设置了第二燃烧室11，它通过一条或多条连接通道12与第一燃烧室9相连(这里涉及一个优选的实施例，燃烧室9中也能设置点火液喷射器13)。第二燃烧室11内设置了点火液喷射器13，点火液借助点火液泵16经由点火液管道14供给点火液喷射器13。第三输送装置15的点火液管道14内的压力借助点火液泵16提供。
发动机的换气以公知方式通过通入第一燃烧室9中的进气阀和出气阀(17，18)进行。在该实施例中，燃气空气混合物在燃烧室外制备。属于第二输送装置19的组件、即混合物形成单元20以及燃气供应管道21参与了此过程。
在实施检验周期时，与评估装置25相连的温度传感器26检测气缸2的排气温度并对此进行评估，点火液喷射器13的喷射持续时间和/或喷射体积在此检验周期内发生改变。
图2示出了实施本发明检验方法时从气缸2排出气体的温度变化曲线。该检验方法在此例如以一个检验周期的形式来实施。图中示出了实施该检验方法时气缸2的排气温度的时间变化曲线。标记“m”为负荷温度的平均值，发动机在检验过程之前以及在检验过程期间以该温度运行至时间点t1。喷射持续时间在时间点t1开始下降至最小值。由于喷射持续时间下降，在一段较为短暂的过渡时间后，出现了低于负荷温度平均值“m”的稳定温度，其中，发动机在检验过程之前以及在检验过程期间以该平均温度运行至时间点t1。点火液喷射器的喷射持续时间在时间点t2从最小喷射持续时间延长至最大喷射持续时间。因此，温度在一段较短的过渡时间后重新升高并超过平均值“m”。
点火液喷射器13的喷射持续时间在时间点t3重新回到原来的值。排气温度在一段短暂的过渡持续时间后，再次处于气缸2的平均值“m”的范围内。
图3示出了在实施图2所示检验周期期间从气缸2排出气体的温度变化曲线，点火液喷射器13此时是损坏的。测量开始时，同样出现了与负荷温度平均值一致的排气温度，发动机在检验过程之前以及在检验过程期间以该平均温度运行至时间点t1。无论在时间点t1缩短喷射持续时间还是在时间点t2延长喷射持续时间都不会引起气缸2的排气温度改变。由该检验结果推断出，点火液喷射器13是损坏的。
附图标记
2 气缸
3 气缸盖
4 活塞
5 连杆
6 燃料喷射器
7 燃料管道
8 燃料泵
9 第一燃烧室
11 第二燃烧室
12 连接通道
13 点火液喷射器
14 点火液管道
16 点火液泵
17 进气阀
18 排气阀
20 混合物形成单元
21 燃气供应管道
25 评估装置
26 温度传感器

Claims (18)

1.用于多燃料发动机点火液喷射器的检验方法，该多燃料发动机具有用于将液体燃料输送到气缸(2)的第一燃烧室(9)中的第一输送装置(10)、用于将气体燃料输送到气缸(2)的第一燃烧室(9)中的第二输送装置(19)、带有至少一个用于将点火液输送到第一燃烧室(9)中或输送到与第一燃烧室(9)相通的第二燃烧室(11)中的点火液喷射器(13)的第三输送装置(15)、用于检测多燃料发动机排气温度值的测量装置(26)、以及用于评估由测量装置(26)检测到的排气温度值的评估装置(25)，其中，该方法包括下列步骤：
a)让所述多燃料发动机在液体燃料运行状态下运行，其中所述至少一个点火液喷射器(13)将点火液喷入到第一或第二燃烧室(9，11)中，
b)改变一个或多个点火液喷射器(13)的喷射持续时间和/或喷射体积，以及
c)评估由测量装置(26)在改变期间测得的排气温度值。
2.按权利要求1所述的用于多燃料发动机点火液喷射器的检验方法，其特征在于，所述多燃料发动机在实施所述检验方法期间在低负荷或部分负荷范围内运行。
3.按权利要求2所述的用于多燃料发动机点火液喷射器的检验方法，其特征在于，所述多燃料发动机在额定负荷的5至25％的范围内运行。
4.按前述权利要求之一所述的用于多燃料发动机点火液喷射器的检验方法，其特征在于，所述多燃料发动机在液体燃料运行状态下按柴油机方法工作。
5.按前述权利要求之一所述的用于多燃料发动机点火液喷射器的检验方法，其特征在于，使用柴油作为在液体燃料运行状态下的燃料。
6.按前述权利要求之一所述的用于多燃料发动机点火液喷射器的检验方法，其特征在于，液体燃料运行状态的燃料被用作燃气运行状态的点火液。
7.按前述权利要求之一所述的用于多燃料发动机点火液喷射器的检验方法，其特征在于，第二燃烧室(11)设计为第一燃烧室(9)的预燃室并与第一燃烧室(9)相连。
8.按前述权利要求之一所述的用于多燃料发动机点火液喷射器的检验方法，其特征在于，用于将点火液输送到第一燃烧室(9)中的、所述第三输送装置的点火液喷射器(13)与所述第一输送装置的喷射器(6)集成地构成。
9.按前述权利要求之一所述的用于多燃料发动机点火液喷射器的检验方法，其特征在于，测量装置(26)检测所述多燃料发动机的单个气缸的排气温度值。
10.按前述权利要求之一所述的用于多燃料发动机点火液喷射器的检验方法，其特征在于，测量装置(26)在少数几个气缸冲程后就已经检测到排气温度的变化。
11.按前述权利要求之一所述的用于多燃料发动机点火液喷射器的检验方法，其特征在于，在所述步骤b)中，喷射持续时间被延长，因而更多的点火液到达燃烧室(9，11)。
12.按权利要求11所述的用于多燃料发动机点火液喷射器的检验方法，其特征在于，喷射开始被提前和/或喷射结束被延后。
13.按前述权利要求之一所述的用于多燃料发动机点火液喷射器的检验方法，其特征在于，在所述步骤b)中，喷射持续时间被缩短，因而更少的点火液到达燃烧室(9，11)。
14.按权利要求13所述的用于多燃料发动机点火液喷射器的检验方法，其特征在于，喷射开始被延后和/或喷射结束被提前。
15.按前述权利要求之一所述的用于多燃料发动机点火液喷射器的检验方法，其特征在于，点火液喷射器(13)的喷射持续时间按照预定的检验周期改变。
16.按权利要求1至10之一所述的用于多燃料发动机点火液喷射器的检验方法，其特征在于，在所述步骤b)中，喷入点火液的量借助通过点火液喷射器(13)的体积流量的变化发生改变，因而更多或更少的点火液到达燃烧室(9，11)。
17.按权利要求16所述的用于多燃料发动机点火液喷射器的检验方法，其特征在于，点火液喷射器(13)的体积流量按照预定的检验周期改变。
18.按前述权利要求之一所述的用于多燃料发动机点火液喷射器的检验方法，其特征在于，依次检验单个点火液喷射器(13)。
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CN102628408A (zh) * 2011-02-07 2012-08-08 奥迪股份公司 用于识别发动机的燃料箱中的燃料品质的方法和设备
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CN102628408B (zh) * 2011-02-07 2015-08-19 奥迪股份公司 用于识别发动机的燃料箱中的燃料品质的方法和设备
CN103958860A (zh) * 2011-11-30 2014-07-30 爱三工业株式会社 双燃料内燃机的燃料供给控制装置以及在双燃料内燃机中切换燃料的方法
CN106460741A (zh) * 2014-03-17 2017-02-22 伍德沃德有限公司 预燃室在双燃料源发动机中的使用
CN105937469A (zh) * 2015-03-06 2016-09-14 曼柴油机和涡轮机欧洲股份公司 用于对点火流体喷射器进行功能检查的方法和控制装置
CN109958540A (zh) * 2017-12-22 2019-07-02 卡特彼勒发动机有限及两合公司 用于起动气体燃料内燃机的方法
CN109958540B (zh) * 2017-12-22 2022-11-22 卡特彼勒发动机有限及两合公司 用于起动气体燃料内燃机的方法
CN110469439A (zh) * 2019-08-30 2019-11-19 攀钢集团矿业有限公司 排气温度测试判定电磁喷油器性能的方法

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KR101381257B1 (ko) 2014-04-02
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DE102008004078A1 (de) 2009-07-23
KR20090077875A (ko) 2009-07-16
JP4663017B2 (ja) 2011-03-30
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