Characterization of the low temperature chemistry of large hydrocarbons for model development in motor control

用于电机控制模型开发的大分子碳氢化合物的低温化学表征

• 批准号: 449599893
• 负责人: Professorin Dr. Tina Kasper
• 金额: --
• 依托单位: Lehrstuhl für Thermodynamik und Energietechnik (ThEt)
• 依托单位国家: 德国
• 项目类别: Research Units
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/449599893?language=en
• 关键词: Characterization; low; temperature; chemistry; large

Low-temperature combustion (NTV) can increase the efficiency of engines while reducing their emissions. In NTV a fuel-air mixture that is as homogeneous as possible is produced and burned after self-ignition. The FOR2401 develops approaches for the control of NTV processes that allow engines to be operated transiently and stably in a wide characteristic field. A particular challenge in the control of NTV processes are the cyclic fluctuations across scales caused by the convolution of reaction-kinetic and fluid mechanical effects. Consequently, the concept of the FOR2401 is to develop a multi-scale control. NTV processes can be controlled through controlled multiple injections, intermediate compression, exhaust gas recirculation and water injection. Since ignition and pollutant formation processes are determined by the kinetics of the substances and reactions involved in the process under the conditions set by the control interventions, kinetic questions arise concerning the reaction sequences during the conversion of partially combusted mixture with additional fuel, during ignition and during the formation of pollutants.To investigate these open questions, the conversion of fuel-air mixtures in a flow reactor and a well-stirred reactor is analyzed by mass spectrometry and gas chromatography. By varying the pressure, the reaction temperature, the residence time and the equivalence ratio, data sets are obtained from which conclusions on the reaction pathways can be drawn. Experimentally, pressures of up to 20 bar are realized, in particular to investigate the conditions of intermediate compressions or multiple injections. The work systematically addresses the reaction kinetics of the n-alkanes from n-heptane to n-dodecane, i-octane, toluene and methylcyclohexane, which are surrogate components of diesel or gasoline. Within the FOR2401, the data will be used to improve the reaction mechanism that predicts the reactivity under engine conditions and thus integrates the kinetic principles into the control strategies.In addition, the relationship between ion formation during combustion and the thermodynamic state of the combusted gas mixture will be investigated to determine how the ion current signal, which is comparatively easy to measure in the engine, can be used in combination with the cylinder pressure as a control parameter. For this purpose, low-pressure flames in which the formation of ions is relatively well known are examined first. The investigations are then extended to the NTV parameter range in the high-pressure reactor in order to find formation reactions at these temperatures. The ion formation is ideally captured in as few formation reactions as possible even at low temperatures and moderate pressures and can then be incorporated in to the control strategies in the form of very small reaction mechanisms.

低温燃烧（NTV）可以提高发动机的效率，同时减少其排放。在NTV中，产生一种尽可能均匀的燃料-空气混合物，并在自燃后燃烧。FOR2401开发了控制NTV过程的方法，使发动机能够在广泛的特性域中瞬态稳定地运行。控制NTV过程的一个特殊挑战是由反应动力学和流体力学效应的卷积引起的跨尺度的循环波动。因此，FOR2401的概念是开发一个多尺度控制。NTV过程可以通过可控多次注入、中间压缩、废气再循环和注水来控制。由于点火和污染物形成过程是由在控制干预措施设定的条件下参与该过程的物质和反应的动力学决定的，因此在部分燃烧的混合物与附加燃料的转化过程中，在点火过程中以及在污染物形成过程中，动力学问题就出现了。为了研究这些悬而未决的问题，用质谱法和气相色谱法分析了流动反应器和均匀搅拌反应器中燃料-空气混合物的转化。通过改变反应压力、反应温度、停留时间和当量比，得到数据集，从而得出反应途径的结论。在实验中，可实现高达20bar的压力，特别是用于研究中间压缩或多次注射的条件。该工作系统地解决了从正庚烷到正十二烷，i-辛烷，甲苯和甲基环己烷的反应动力学，这是柴油或汽油的替代成分。在FOR2401中，这些数据将用于改进反应机制，预测发动机条件下的反应性，从而将动力学原理整合到控制策略中。此外，还将研究燃烧过程中离子形成与燃烧气体混合物热力学状态之间的关系，以确定如何将在发动机中相对容易测量的离子电流信号与气缸压力相结合作为控制参数。为此目的，首先对离子形成相对已知的低压火焰进行研究。然后将研究扩展到高压反应器的NTV参数范围，以便在这些温度下找到地层反应。理想情况下，即使在低温和中压下，也可以在尽可能少的形成反应中捕获离子形成，然后可以以非常小的反应机制的形式纳入控制策略。