Investigation of the chemical kinetics of incomplete oxidation processes in shock tubes

激波管中不完全氧化过程的化学动力学研究

• 批准号: 239921643
• 负责人: Professor Dr. Christof Schulz
• 金额: --
• 依托单位: Institut für Energie- und Material-Prozesse (EMPI)
• 依托单位国家: 德国
• 项目类别: Research Units
• 财政年份: 2013
• 资助国家: 德国
• 起止时间: 2012-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/239921643?language=en
• 关键词: Investigation; chemical; kinetics; incomplete; oxidation

The development of polygeneration processes requires detailed knowledge about chemical processes in reaction systems with a large fuel excess. On one hand, information about the limiting conditions between gas-phase processes and soot formation is necessary, on the other hand, validated reaction mechanisms are required to enable a simulation-based development and optimization of polygeneration processes. In the first funding period, partial oxidation of methane was studied at phi = 2. Additives were used to accelerate the autoignition of methane so that engines can be operated in a self-igniting mode at polygeneration conditions. Under the conditions investigated so far, besides CO2 and H2O, mostly synthesis gas (CO & H2) was formed. In the second funding period, the studies were expanded towards mixtures with even higher fuel excess that enable the formation of carbon-carbon bonds and the generation of unsaturated hydrocarbons. Here, natural gas and new additives (DME and DEE) were used. Measured ignition delay times and product compositions served as basis for further development of the FOR1993-based mechanism (PolyMech) in project GM1.Since the additives account for a significant part of the fuel consumption at fuel-rich conditions, the next funding period will focus on ozone as an additive using the previously established experimental approaches. Ozone has the advantage that it increases the reactivity of the fuel even in very low concentrations. An additional advantage is that it can be generated online at low cost with an ozone generator. Its reaction kinetics in fuel-rich conditions, however are not sufficiently studied so far. As validation data within the FOR1993, ignition delay times, end product concentrations, and time-resolved methane, ozone, carbon monoxide concentrations, and temperatures will be measured in the shock tube using methane and natural gas as fuels.Increasing the amount of air in very fuel-rich conditions increases the fuel consumption, but also leads to higher end temperatures that promote the formation of soot. By using oxygenated additives, soot formation can be suppressed because they shift the low- temperature onset of soot formation towards higher temperatures. In this context, the suitability of various additives such as alcohols or ethers will be investigated in the shock tube by measuring soot inception times and soot volume fractions. In addition, time-resolved detection of soot precursors such as benzene and PAH (polycyclic aromatics) via spectrally- and temporally-resolved absorption measurements will help to determine the limiting conditions for soot formation with and without additives. From these results, conditions will be determined, in which the soot formation in polygeneration processes can be avoided in the engine.

多代过程的发展需要有关燃料过量较大的反应系统中化学过程的详细知识。一方面，需要有关气相过程和烟灰形成之间的限制条件的信息，另一方面，需要经过验证的反应机制，以实现基于模拟的发展和优化多代过程。在第一个资金期间，在PHI = 2时研究了甲烷的部分氧化。添加剂被用于加速甲烷的自动签名，以便在多代条件下可以在自我刻击模式下进行发动机。在迄今为止研究的条件下，除了CO2和H2O之外，还形成了合成气（CO＆H2）。在第二个资金期间，研究扩展到具有更高燃料过量的混合物，从而使碳碳键的形成和不饱和烃的产生。在这里，使用了天然气和新添加剂（DME和DEE）。测得的点火延迟时间和产品组成是在项目GM1中进一步开发基于1993的机制（Polymech）的基础。由于添加剂在燃料富裕条件下添加了很大一部分燃料消耗的重要部分，下一个资金将使用先前建立的实验方法作为杂项。臭氧具有一个优势，即即使在非常低的浓度下，它也会增加燃料的反应性。另一个优势是，它可以通过臭氧发电机以低成本在线生产。到目前为止，其在燃料富含燃料条件下的反应动力学尚未得到充分研究。作为1993年内的验证数据，点火延迟时间，最终产品浓度以及时间分辨的甲烷，臭氧，一氧化碳浓度和温度将在冲击管中使用甲烷和天然气体作为燃料作为燃料。在非常燃料的条件下灌输空气量增加了燃油消耗量，但也会增加燃油效果，从而促进更高最终的温度，从而促进促进良好的形式，从而促进了Sopations的形式。通过使用氧化添加剂，可以抑制烟灰的形成，因为它们将烟灰形成的低温发作转移到更高的温度上。在这种情况下，将通过测量烟灰开始和烟灰体积分数来研究各种添加剂（例如醇或醚）的适用性。此外，通过光谱和时间分辨的吸收测量值（苯和PAH（多环芳烃））的烟灰前体的时间分辨检测将有助于确定带有和无添加剂的烟灰形成的限制条件。从这些结果中，将确定条件，其中可以在发动机中避免多代过程中的烟灰形成。