Experimental and kinetic study on O2 reduced and enriched premixed ammonia/DME flames

IF 6.2 2区工程技术 Q2 ENERGY & FUELS

Journal of The Energy Institute Pub Date : 2025-08-28 DOI:10.1016/j.joei.2025.102276

Chengcheng Zhang , Liming Dai , Yuesheng Wang , Xiangjun Qu , Xiying Chen , Qian Wang

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引用次数: 0

Abstract

Co-firing ammonia (NH₃) with dimethyl ether (DME) offers a promising pathway for utilizing ammonia in compression ignition engines. In this study, the laminar burning velocities (LBV) of NH₃/DME flames were measured at a wide range of conditions, with initial temperatures varying from 298 K to 473 K, pressure changing from 1 to 5 bar and equivalence ratio (

) varying from 0.4 - 2.1. The DME fraction in the fuel was set at 0%, 20%, 40% and 100% and oxygen (O₂) fraction in the oxidizers was set at 18%, 21%, 25% and 35% to cover O₂ reduced and O₂ enriched conditions. The measurements suggest that either adding DME or increasing O₂ fraction has almost linear enhancing effect on the LBV of NH₃ flames and widens the flammable range of premixed NH₃ flames. An optimized NH₃/DME is proposed in this study, which can accurately reproduce the measured LBVs from this study and measured ignition delay times (IDT) from our previous study. Kinetic analysis suggests that with 20% DME addition, the LBV is mainly controlled by DME chemistry, whereas O₂ variation has marginal effect on the dominating reactions for LBV and reaction path. Sensitivity analysis on IDT implies that with 20% DME addition, the low temperature autoignition chemistry of DME primarily dominates the autoignition process. DME addition has a non-monotonical effect on NO because of a ‘trade-off’ relationship between HNO and the radical pool induced by DME addition, while O₂ shows a linear correlation with NO concentration due to linearly boosted flame temperature and radical pool concentration.

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O2还原和富集氨/二甲醚预混火焰的实验与动力学研究

氨（NH3）与二甲醚（DME）共烧为氨在压缩点火发动机中的应用提供了一条很有前途的途径。在本研究中，测量了NH3/DME火焰在不同条件下的层流燃烧速度（LBV），初始温度为298 ~ 473 K，压力为1 ~ 5bar，等效比（）为0.4 ~ 2.1。二甲醚在燃料中的分数分别为0%、20%、40%和100%，氧（O2）在氧化剂中的分数分别为18%、21%、25%和35%，以覆盖O2还原和O2富集的条件。结果表明，添加二甲醚或增加O2分数对NH3火焰的LBV均有近似线性的增强作用，并扩大了预混NH3火焰的可燃范围。本研究提出了一种优化的NH3/DME，可以准确地再现本研究测量的LBVs和我们之前研究测量的点火延迟时间（IDT）。动力学分析表明，当二甲醚添加量为20%时，LBV主要受二甲醚化学反应的控制，而O2变化对LBV的主导反应和反应路径影响较小。IDT敏感性分析表明，二甲醚添加量为20%时，二甲醚的低温自燃化学反应主导了自燃过程。二甲醚的加入对NO的影响是非单调的，因为二甲醚的加入导致HNO和自由基池之间存在“权衡”关系，而O2与NO浓度呈线性相关，因为火焰温度和自由基池浓度呈线性升高。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Journal of The Energy Institute 工程技术-能源与燃料

CiteScore

10.60

自引率

5.30%

发文量

166

审稿时长

16 days

期刊介绍： The Journal of the Energy Institute provides peer reviewed coverage of original high quality research on energy, engineering and technology.The coverage is broad and the main areas of interest include: Combustion engineering and associated technologies; process heating; power generation; engines and propulsion; emissions and environmental pollution control; clean coal technologies; carbon abatement technologies Emissions and environmental pollution control; safety and hazards; Clean coal technologies; carbon abatement technologies, including carbon capture and storage, CCS; Petroleum engineering and fuel quality, including storage and transport Alternative energy sources; biomass utilisation and biomass conversion technologies; energy from waste, incineration and recycling Energy conversion, energy recovery and energy efficiency; space heating, fuel cells, heat pumps and cooling systems Energy storage The journal''s coverage reflects changes in energy technology that result from the transition to more efficient energy production and end use together with reduced carbon emission.