共查询到19条相似文献,搜索用时 109 毫秒
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贾继德 《小型内燃机与摩托车》1997,(1)
汽油机爆燃具有较大的危害,采用爆燃控制系统可以控制爆燃的发生,及改善发动机的经济性和动力性。本文介绍了已装车实用化的爆燃控制点火系统的组成、工作原理,并对爆燃传感器的特点进行了论述 相似文献
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采用加速度传感器测量SQR480车用电控汽油机机体振动情况来反映其爆燃情况.通过在线调整点火提前角,为产生或消除爆燃提供条件,获得相应的发动机机体振动信号.采用Welch功率谱估计法对机体振动信号进行频谱分析,可确定适用于爆燃检测的爆燃特征频率为7.9~8.3kHz. 相似文献
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主要论述汽油机中燃料燃烧时中间产物OH(306.4nm)、CH(431.5nm)、C2(516.5nm)自由基的吸光度在正常燃烧和爆燃时的不同变化,在燃烧室中心区和终燃区的差别,并分析了发生爆燃时柴油机及快速压缩机型中的压力-时间变化关系,这有助于进一步弄清爆燃的机理。 相似文献
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缸内直喷和增压已成为当今汽油机技术的主流方向,然而,随着发动机小型化和动力性的提高,增压直喷汽油发动机出现了一种新的异常燃烧现象——超级爆燃,其严重影响着发动机性能和使用寿命。根据国内外超级爆燃的研究现状,在典型增压直喷汽油机上对不同的超级爆燃抑制方法进行了研究。结果表明:加浓、二次喷射、冷型火花塞都能够抑制超级爆燃。 相似文献
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管内爆燃转爆轰的热力学原理 总被引:2,自引:0,他引:2
本文首先说明了燃烧的两种传播机制,一种是燃烧自身的蔓延,国一种是由运动速度比火焰传播速度快的点火源引导而形成的传播,进而指出了可能存在的两种不稳定燃烧状态和两种极端物理过程的爆轰波,一种不稳定燃烧状态由爆燃加速到超过临界速度而致,另一种不稳定燃烧状态则由激波诱导燃烧引起,并采用简化理论计算了燃烧产物的压力和熵增随燃烧度的变化规律。由此出发,本文试图从热力学角度说明管内火中速及爆燃转爆轰的原理。爆燃 相似文献
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基于火花塞离子电流信号的发动机爆震检测研究 总被引:4,自引:0,他引:4
气缸内燃烧时产生大量的离子,在火花塞上施加适当偏置电压就会形成离子电流。离子电流信号包含了丰富的燃烧信息。作者研究了焰后区的离子电流信号与爆震的关系。试验表明离子电流高频部分的平均能量的大小与爆震有关,可以用于检测爆震的发生和强度。同时还给出了基于离子电流信号的临界爆震强度与转速之间的关系。 相似文献
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《International Journal of Hydrogen Energy》2022,47(87):37072-37089
In this paper, the knock phenomenon of reactivity controlled compression ignition (RCCI) engine fueled with natural gas/diesel was numerically studied. The knock mechanism of the RCCI engine is explained and the strategy of suppressing knock is put forward. The knock characteristics were studied by setting monitoring points in different spaces positions of the cylinder. The results show that the pressure oscillation amplitude at the center and edge of the cylinder is large under the high load condition of RCCI engine. In addition, the knock mechanism was studied by using pressure difference method, maximum amplitude of pressure oscillation, important components, temperature isosurface, pressure fluctuation and heat release rate. The results show that the knock of RCCI engine is mainly caused by the end-gas auto-ignition. The pressure difference results show that the characteristic frequency is consistent with the natural resonance mode (0,1) of the cylindrical combustion chamber. On this basis, the effects of pilot oil injection timing and compression ratio on engine knock are further studied. It is confirmed that diesel knock and end-gas knock may exist simultaneously in the same cycle when RCCI engine knock occurs. And diesel knock occurs before top dead center, and end-gas knock occurs after top dead center. Proper adjustment of pilot oil injection timing and reduction of compression ratio can effectively suppress engine knock. 相似文献
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Yong Li Wenzhi Gao Pan Zhang Zhen Fu Xingda Cao 《International Journal of Hydrogen Energy》2021,46(21):11982-11993
Hydrogen has become an ideal alternative fuel for internal combustion engines. However, with an increase in the equivalence ratio and compression ratio, knock combustion is more likely to occur, which limits its engineering application. In this study, the effects of the equivalence ratio on the knock under different compression ratios were studied through numerical simulation. The signal energy ratio (SER) were used to evaluate the knock onset (KO). The knock intensity (KI) and engine performance were compared and analyzed under different equivalence ratios and compression ratios. The results revealed that a high compression ratio can significantly amplify the effect of the equivalence ratio on combustion and knock. Under the compression ratio of 17.5, KI increases more quickly, with the constant equivalence ratio rise and is more sensitive to ignition timing with equivalence ratio increasing. For the compression ratio of 11, the ignition timing limited by knock is about 4°CA earlier than that of compression ratio of 17.5, and the engine performance is more stable in the low-knock zone. However, when KI exceeds 1 MPa, the power and ITE decreases 20.6% and 20.9% respectively. 相似文献
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本文应用自行研制的火花塞光纤传感测量系统对 BJ492Q汽油机爆震燃烧进行测量和研究,同时用压力传感器、振动传感器进行对比,分析了爆震燃烧时火焰光辐射的变化情况。正常燃烧时,CH(431.5nm)、C2(516.5nm)、H2O*(588nm自由基的光强曲线出现双峰值,着火延迟期内为自由基光辐射。爆震较强工况,只出现一个光强峰值,主要是碳粒子热辐射,峰值处出现剧烈波动,相位提前,无自由基的光辐射。压力曲线与光强曲线有很好的一致性。试验表明,火花塞光纤传感器抗干扰好,成本低,工作可靠,信号强,完全可用于爆震测量。 相似文献
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火花点火发动机爆震强度评价指标的研究 总被引:13,自引:4,他引:13
在CA1102单缸汽油试验机上测量采集了不同工况,不同爆震强度时的压力示功图,用国外现有的7种爆震强度评价指标对测得的数据进行了计算分析,阐述了各种指标的优缺点及用于汽车发动机实时控制的可能性,讨论了实现爆震精确测量和实时控制的要求。 相似文献