Proceedings of the Combustion Institute最新文献_第6页

Detailed Modeling of Flame-Wall-Interactions under the influence of phosphorous-containing Flame Retardants and development of a reduced kinetic model 含磷阻燃剂影响下火焰-壁面相互作用的详细建模及简化动力学模型的建立

IF 5.2 2区工程技术 Q2 ENERGY & FUELS

Proceedings of the Combustion Institute

Pub Date : 2025-01-01 DOI: 10.1016/j.proci.2025.105833

Vanessa Stegmayer, Ulrich Maas, Christina Strassacker

Fire safety engineering plays a vital role in safeguarding lives, property, and the environment by preventing and mitigating fire hazards in buildings, materials, and systems. Phosphorus-based flame retardants, such as dimethyl methylphosphonate (DMMP), are studied for their effectiveness in inhibiting combustion processes. This study investigates the impact of flame retardants on Flame-Wall Interactions by adding varying amounts of DMMP to a premixed methane/air Head-On Quenching flame, where the flame propagates towards a cold wall and extinguishes. Reduced kinetic models for these systems with different DMMP concentrations are developed using the Reaction-Diffusion Manifold (REDIM) method. The REDIM is constructed and validated by comparing results of detailed and reduced kinetics. In this way, the quality of the REDIM reduced kinetics can be verified for the different phenomena resulting due to the inhibiting character of flame retardants. It is shown that the reduced kinetics reproduce the results of the Flame-Wall Interactions under the influence of flame retardants very accurately. The inhibiting character of the flame retardants with respect to the chemical kinetics is well captured, even though it challenges the generation of the reduced kinetics as the amount of added DMMP is very low and in the magnitude of minor species. Additionally, the sensitivity of the simulation with reduced kinetics on the gradient estimate is investigated, showing little to no sensitivity. This model offers significant potential for fire safety engineering, as the drastic reduction in the number of equations enables the analysis of realistic scenarios facilitating the design of safer systems.

消防安全工程通过预防和减轻建筑物、材料和系统中的火灾隐患，在保护生命、财产和环境方面发挥着至关重要的作用。磷系阻燃剂，如甲基膦酸二甲酯（DMMP），研究其在抑制燃烧过程中的有效性。本研究通过在预混甲烷/空气中加入不同数量的DMMP来研究阻燃剂对火焰-壁相互作用的影响，在预混甲烷/空气中，火焰向冷壁传播并熄灭。采用反应-扩散歧管（REDIM）方法建立了不同DMMP浓度下这些体系的简化动力学模型。通过比较详细和简化的动力学结果，构建了REDIM并对其进行了验证。通过这种方法，可以验证由于阻燃剂的抑制特性而产生的不同现象的REDIM还原动力学的质量。结果表明，还原动力学可以很准确地再现在阻燃剂作用下的火焰壁相互作用的结果。阻燃剂在化学动力学方面的抑制特性被很好地捕获，尽管它挑战了减少动力学的产生，因为添加DMMP的量非常低，并且在次要物种的量级上。此外，研究了减少动力学的模拟对梯度估计的敏感性，显示出很少或没有敏感性。该模型为消防安全工程提供了巨大的潜力，因为方程式数量的急剧减少使分析现实情况有助于设计更安全的系统。

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引用次数: 0

Two-stage optimization for chemical kinetic mechanisms with improved deep reinforcement learning 基于改进深度强化学习的化学动力学机制两阶段优化

IF 5.2 2区工程技术 Q2 ENERGY & FUELS

Proceedings of the Combustion Institute

Pub Date : 2025-01-01 DOI: 10.1016/j.proci.2025.105953

Hao Hu , Huangwei Zhang

Accurate modeling of fuel chemistry remains a fundamental yet challenging task in combustion research due to significant uncertainties in reaction rate parameters. Existing approaches for chemical kinetic mechanism optimization, ranging from stochastic searches to Bayesian inference, are often limited by local optima or excessive computational cost when applied to high-dimensional problems. To overcome these challenges, we propose a novel two-stage optimization framework, IDRL-MCMC, which combines a stochastic optimizer based on improved deep reinforcement learning (IDRL) with Bayesian inference via Markov chain Monte Carlo (MCMC). As a key innovation, IDRL enhances canonical actor-critic DRL by embedding a surrogate model into the critic and applying an active sampling strategy, enabling efficient and scalable exploration for complex uncertainty spaces. MCMC is then performed within a reduced space identified by IDRL to accurately estimate the posterior distributions of the rate parameters. This framework effectively bridges stochastic optimization and probabilistic inference, leveraging the global search capability of DRL with the statistical rigor of MCMC. A 550-dimensional ammonia combustion mechanism is used for validation, benchmarked against conventional stochastic optimizers and surrogate-assisted Bayesian methods. Results show that IDRL-MCMC achieves a 3-6 times reduction in computational costs while delivering significantly improved optimization accuracy, demonstrating its potential for high-dimensional and complex mechanism development.

由于反应速率参数存在很大的不确定性，燃料化学的精确建模一直是燃烧研究中一项基本而又具有挑战性的任务。现有的化学动力学机制优化方法，从随机搜索到贝叶斯推理，在应用于高维问题时，往往受到局部最优或计算成本过高的限制。为了克服这些挑战，我们提出了一个新的两阶段优化框架，IDRL-MCMC，它结合了基于改进深度强化学习（IDRL）的随机优化器和通过马尔可夫链蒙特卡罗（MCMC）的贝叶斯推理。作为一项关键创新，IDRL通过将代理模型嵌入到评论家中并应用主动采样策略来增强规范的行动者-评论家DRL，从而实现对复杂不确定性空间的高效和可扩展的探索。然后在IDRL识别的缩小空间内进行MCMC，以准确估计速率参数的后验分布。该框架有效地连接了随机优化和概率推理，利用了DRL的全局搜索能力和MCMC的统计严谨性。550维氨燃烧机制用于验证，对传统的随机优化器和代理辅助贝叶斯方法进行基准测试。结果表明，IDRL-MCMC的计算成本降低了3-6倍，同时显著提高了优化精度，显示了其在高维复杂机构开发中的潜力。

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引用次数: 0

Experimental study on combustion and emission characteristics of an ammonia-diesel dual-fuel engine under single and double injection strategies 氨柴油双燃料发动机单喷和双喷燃烧与排放特性试验研究

IF 5.2 2区工程技术 Q2 ENERGY & FUELS

Proceedings of the Combustion Institute

Pub Date : 2025-01-01 DOI: 10.1016/j.proci.2025.105872

Shouzhen Zhang, Qinglong Tang, Rui Yang, Haifeng Liu, Mingfa Yao

This study compares the effects of single and double diesel injection strategies on the combustion and emission characteristics of an ammonia-diesel dual-fuel engine at medium loads, as well as their potential for reducing greenhouse gas (GHG) emissions under different ammonia substitution ratios. At a 70% ammonia substitution ratio, single injection with early injection timing enhances the local mixture reactivity, shortens the ignition delay, and strengthens the diesel ignition, thereby improving ammonia combustion efficiency. Under the double injection strategy, the pilot injection of diesel forms a premixed charge with ammonia in the cylinder, accelerating the overall combustion speed and shortening the combustion duration compared to single injection, which benefits thermal efficiency. Overall, at a low ammonia substitution ratio (50%), the double injection strategy shows advantages in terms of indicated thermal efficiency (ITE) and GHG emissions. However, at a higher ammonia substitution ratio (70%), the ITE of both single and double injection strategies is nearly identical, but single injection results in lower emissions of GHG, N₂O, and unburned NH₃. At a 70% ammonia substitution ratio, the minimum GHG emissions of the single injection strategy reach 229.9 g/kW·h, representing a 61.5% reduction compared to the pure diesel mode. This demonstrates that the ammonia-diesel dual-fuel mode has significant potential for GHG reduction in internal combustion engines.

本研究比较了单喷和双喷柴油策略对氨柴油双燃料发动机中负荷燃烧和排放特性的影响，以及在不同氨替代比下减少温室气体排放的潜力。在氨替代比为70%时，单次喷油提前喷油，增强了混合气的局部反应性，缩短了点火延迟，增强了柴油机的点火能力，从而提高了氨燃烧效率。双喷策略下，柴油先导喷与氨在缸内形成预混装药，与单喷相比，整体燃烧速度加快，燃烧时间缩短，有利于热效率的提高。总体而言，在低氨替代比（50%）下，双注入策略在指示热效率（ITE）和温室气体排放方面显示出优势。然而，在较高的氨替代比（70%）下，单次和双次喷注策略的ITE几乎相同，但单次喷注导致GHG、N2O和未燃烧NH3的排放更低。当氨替代率为70%时，单次喷射策略的最小温室气体排放量达到229.9 g/kW·h，比纯柴油模式减少61.5%。这表明氨-柴油双燃料模式在内燃机中具有显著的温室气体减排潜力。

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引用次数: 0

Bayesian MCMC estimation of the limiting oxygen concentrations for laboratory electrical wires in various gravity levels 不同重力水平下实验室电线极限氧浓度的贝叶斯MCMC估计

IF 5.2 2区工程技术 Q2 ENERGY & FUELS

Proceedings of the Combustion Institute

Pub Date : 2025-01-01 DOI: 10.1016/j.proci.2025.105869

Yuxuan Ma , Taro Takemata , Fangsi Ren , Shinji Nakaya , Mitsuhiro Tsue

Scaling analysis offers a promising approach for predicting the flammability of electrical wires in manned space missions, yet determining the high-dimensional model parameter vector remains challenging, particularly when extrapolating to unknown gravities. This study introduces an effective method for predicting the limiting oxygen concentration (LOC) of electrical wires across different gravities, by integrating physical flame spread modeling with the data-driven technique and ground-based experimental data. A flame spread model for thin wires was developed based on the energy conservation law, and the LOC is determined by the existence of a stable-physical solution to the resulting nonlinear equation. Model parameters were estimated using a Bayesian approach, specifically the Markov Chain Monte Carlo (MCMC) method, trained on experimental LOC data under various hypergravity and opposed flow conditions. The results demonstrate the model’s capability to predict LOC curves accurately across gravity levels, providing fire safety margins based on uncertainties in model parameters and experimental measurements. The physics underlying the inferred parameter values was discussed, showing the important role of boundary layer effect and structure of the flame front. The interdependence of model parameters governing the blowoff or quenching branches allows for their values to be inferred via posterior distributions or inherent correlations. Interestingly, despite notable variations in quenching and blowoff branches, the predicted minimum LOC (MLOC) remains largely unchanged from 0 g to 4 g, thus it appears feasible to consider MLOC as a quasi-intrinsic property of the tested wire itself. Stable flame spread cannot be sustained in low-speed, low-gravity environments, even in oxygen-enriched atmospheres, due to the significant radiative heat loss. This “physics-informed data-driven” modelling approach bridges the gap between uncertainties in scaling analysis and practical flammability evaluations, thereby offering a more reliable methodology for screening spacecraft materials using ground-based facilities that support fire safety for space missions to Moon and Mars.

尺度分析为预测载人航天任务中电线的可燃性提供了一种很有前途的方法，但确定高维模型参数向量仍然具有挑战性，特别是在推断未知重力时。本文介绍了一种有效的方法，通过将物理火焰传播模型与数据驱动技术和地面实验数据相结合，预测不同重力下电线的极限氧浓度（LOC）。基于能量守恒定律建立了细导线的火焰传播模型，并通过求解的非线性方程的稳定物理解来确定LOC。模型参数的估计使用贝叶斯方法，特别是马尔可夫链蒙特卡罗（MCMC）方法，在各种超重力和反向流动条件下的实验LOC数据进行训练。结果表明，该模型能够准确预测不同重力水平的LOC曲线，并基于模型参数和实验测量的不确定性提供火灾安全裕度。讨论了推导出的参数值背后的物理性质，说明了边界层效应和火焰锋面结构的重要作用。控制排气或淬火分支的模型参数的相互依赖性允许通过后验分布或固有相关性来推断它们的值。有趣的是，尽管淬火和吹断分支有显著变化，但预测的最小LOC （MLOC）在0 g到4 g期间基本保持不变，因此将MLOC视为被测线材本身的准本征特性似乎是可行的。由于大量的辐射热损失，在低速、低重力环境中，甚至在富氧大气中，火焰的稳定蔓延也无法持续。这种“物理数据驱动”的建模方法弥补了尺度分析中的不确定性和实际可燃性评估之间的差距，从而为使用支持月球和火星空间任务消防安全的地面设施筛选航天器材料提供了更可靠的方法。

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引用次数: 0

Sectional modelling of TiO2 particle size distribution and crystallinity in burner-stabilised stagnation flames 在燃烧器稳定停滞火焰中TiO2粒度分布和结晶度的截面建模

IF 5.2 2区工程技术 Q2 ENERGY & FUELS

Proceedings of the Combustion Institute

Pub Date : 2025-01-01 DOI: 10.1016/j.proci.2025.105855

Jiajun Qiu , Lu Tian , Adrian Spencer , R. Peter Lindstedt

The use of flames as heat sources for producing high-quality nanoparticles has gained significant attention due to its one-step, high-throughput nature and the absence of liquid by-products compared to traditional wet chemistry methods. Titanium nanoparticles, such as, Titanium Dioxide (TiO₂), have been widely used as photocatalysts for solar cells and semiconductors for gas sensors. Macroscopic properties of the produced

are directly influenced by nanoscale characteristics of particles, such as, Particle Size Distributions (PSDs) and crystalline phase composition. Accurate modelling of nanoparticles characteristics is vital for producing high-quality nanomaterials in industrial applications. A mass- and number-density-preserving sectional method, originally developed for soot PSDs, is here extended to compute titanium dioxide nanoparticle size distributions. The gas-phase chemistry combines a detailed C/H/N/O mechanism with a Ti 25-species 65-reaction chemical mechanism for Titanium Tetra-Iso-Propoxide (TTIP) decomposition to

. The mechanism features inception of

particles through barrierless dissociation of

. Coagulation and aggregation using varying primary particle diameters are explored and surface growth is assumed via condensation of

molecules on the particle surface. Crystalline phase transport equations are proposed and integrated with the sectional model to provide the crystalline phase fraction in each section, while two distinct phase identification models are used to determine the boundary conditions. The methodology is applied to the formation of TiO₂ in three sets of laminar, premixed, ethylene-oxygen-argon stagnation flame experimentally studied by Tolmachoff et al. (Proc. Combust. Inst., 2009) and Manuputty et al. (Combust. Flame, 2021 and J. Aerosol Sci, 2019). Results are compared with experimental data for PSDs of TiO₂ and phase composition with TTIP loading from 194 ppm to 1454 ppm. Satisfactory results are obtained for all datasets under fuel-lean, stoichiometric, and fuel-rich conditions, supporting the applicability of the augmented sectional model in simultaneously predicting both PSDs and crystalline phase fractions.

与传统的湿化学方法相比，使用火焰作为热源生产高质量纳米颗粒由于其一步，高通量和无液体副产物的性质而受到了极大的关注。钛纳米颗粒，如二氧化钛（TiO2），已被广泛用作太阳能电池的光催化剂和气体传感器的半导体。颗粒的纳米尺度特征，如粒径分布（psd）和晶相组成，直接影响所生产的宏观性能。纳米粒子特性的精确建模对于在工业应用中生产高质量的纳米材料至关重要。一种质量和数量密度保持截面方法，最初是为煤烟psd开发的，在这里扩展到计算二氧化钛纳米颗粒的尺寸分布。气相化学结合了详细的C/H/N/O机制和Ti 25种65反应化学机制，将四异丙醇钛（TTIP）分解成。该机制的特点是粒子通过无障碍解离而开始。研究了不同原始颗粒直径的凝聚和聚集，并通过分子在颗粒表面的凝聚假设表面生长。提出了晶体相输运方程，并将其与截面模型相结合，给出了各截面的晶体相分数，同时采用两种不同的相识别模型确定了边界条件。该方法应用于由Tolmachoff等人（Proc. comust）实验研究的三组层流、预混、乙烯-氧-氩气停滞火焰中TiO2的形成。Inst., 2009)和Manuputty等人(燃烧。火焰，2021；J.气溶胶科学，2019)。将实验结果与TTIP在194 ~ 1454 ppm范围内负载TiO2的psd和相组成的实验数据进行了比较。在低燃料、化学计量和富燃料条件下，所有数据集都获得了令人满意的结果，支持了增强截面模型在同时预测psd和结晶相分数方面的适用性。

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引用次数: 0

Combustion dynamics of axially-staged lean-premixed H2/CH4/air flames 轴向分级贫预混H2/CH4/空气火焰的燃烧动力学

IF 5.2 2区工程技术 Q2 ENERGY & FUELS

Proceedings of the Combustion Institute

Pub Date : 2025-01-01 DOI: 10.1016/j.proci.2025.105877

Yongseok Choi , Gyeonghyun Han , Kyu Tae Kim

Axial fuel staging methods employed at gas turbine combustors—dividing the combustor’s reaction zone into multiple stages along the axial direction—provide improved management of combustion processes, thereby enhancing efficiency and decreasing nitrogen oxide emissions. However, such multi-flame configurations can provoke complex and severe thermoacoustic instabilities due to the intricate interactions between the flame dynamics and combustor acoustics. In this study, we investigate the key thermoacoustic behaviors of an axially staged combustor, with particular emphasis on the nonlinear dynamics of the second-stage jet-in-crossflow flame. To address these phenomena, we carry out measurements of self-excited combustion instability under various staged operating conditions and analyze the data by means of a time-series analysis, high-speed imaging, and phase-synchronized evaluation. The findings demonstrate that the acoustic modes, driven by the primary and secondary flames, arise at different timescales and occur either individually or concurrently. Under the simultaneous excitation of two distinct acoustic modes, the transverse jet flame undergoes complex modal dynamics characterized by seemingly aperiodic amplitude fluctuations in its heat release rate, influenced by a crossflow oscillating at a different frequency, which is induced by the dynamics of the primary flame. Visualized flame dynamics show that the interaction between the crossflow and transverse jet flame itself affects the formation and development of the flame structure, either hindering or promoting coherent flame fronts, and consequently influencing the heat release. Interestingly, the Rayleigh index distribution for the jet flame reveals that, even under crossflow-induced flapping, its energy-contributing region remains concentrated near the nozzle exit.

燃气轮机燃烧室采用的轴向燃料分级方法——沿着轴向将燃烧室的反应区划分为多个阶段——改善了燃烧过程的管理，从而提高了效率，减少了氮氧化物的排放。然而，由于火焰动力学和燃烧室声学之间复杂的相互作用，这种多火焰结构会引起复杂而严重的热声不稳定性。在这项研究中，我们研究了轴向分级燃烧室的关键热声行为，特别强调了第二级交叉流火焰射流的非线性动力学。为了解决这些现象，我们在不同的阶段操作条件下进行了自激燃烧不稳定性的测量，并通过时间序列分析、高速成像和相位同步评估来分析数据。结果表明，在主火焰和次火焰的驱动下，声波模式在不同的时间尺度上出现，可以单独发生，也可以同时发生。在两种不同声模的同时激励下，横向射流火焰受主火焰动力学诱导的不同频率的横流的影响，其放热速率呈现出看似非周期的幅值波动的复杂模态动力学。可视化火焰动力学表明，横流与横向射流火焰本身的相互作用影响火焰结构的形成和发展，或阻碍或促进火焰锋面的相干，从而影响热量的释放。有趣的是，射流火焰的瑞利指数分布表明，即使在横流诱导的扑动下，其能量贡献区域仍然集中在喷管出口附近。

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引用次数: 0

Effects of copper nitrate (Cu(NO3)2) addition on soot characteristics of ethylene pyrolysis in a laminar flow reactor 硝酸铜（Cu(NO3)2）的加入对层流反应器中乙烯热解烟尘特性的影响

IF 5.2 2区工程技术 Q2 ENERGY & FUELS

Proceedings of the Combustion Institute

Pub Date : 2025-01-01 DOI: 10.1016/j.proci.2025.105875

Qingyan He , Teng Fei , Sen Shao , Qifeng Guo , Xiaoqing You

The effect of copper (Cu) on soot characteristics was studied by adding copper nitrate (Cu(NO₃)₂) to ethylene pyrolysis in a laminar flow reactor. The addition of Cu(NO₃)₂ altered the particle inception mechanism through the formation of “core-shell” particles with a copper “core” surrounded by carbonaceous “shell” layers, based on the results of transmission electron microscopy equipped with energy dispersive spectroscopy (TEM-EDS) and density functional theory (DFT) calculations. This phenomenon was due to the earlier nucleation of Cu (compared to soot nucleation) from the thermal decomposition of Cu(NO₃)₂. On the other hand, based on the particle size distribution results, the addition of Cu(NO₃)₂ did not enhance soot coagulation as the addition of ferrocene did in previous work, due to weaker interaction between Cu and soot precursors/particles from the DFT and molecular dynamics (MD) simulation results. In addition, thermogravimetric analysis results show that soot particles with “core-shell” structure containing Cu were easier to oxidize because they reached the maximum oxidation rate at a lower temperature than those without Cu, implying that Cu could promote soot oxidation as a catalyst.

通过在层流反应器中加入硝酸铜（Cu(NO3)2）进行乙烯热解，研究了铜（Cu）对烟灰特性的影响。基于能量色散能谱（TEM-EDS）和密度泛函理论（DFT）计算结果，Cu(NO3)2的加入改变了粒子的初始机制，通过形成“核-壳”粒子，其中铜“核”被碳质“壳”层包围。这种现象是由于Cu(NO3)2的热分解使Cu(NO3)2的成核比烟灰的成核早。另一方面，基于粒径分布结果，由于DFT和分子动力学（MD）模拟结果显示Cu(NO3)2与烟尘前驱体/颗粒之间的相互作用较弱，因此Cu(NO3)2的加入并没有像二茂铁的加入那样增强烟尘的混凝作用。此外，热重分析结果表明，含有Cu的“核壳”结构的烟尘颗粒比不含Cu的烟尘颗粒更容易氧化，在较低的温度下达到最大氧化速率，这表明Cu可以作为催化剂促进烟尘氧化。

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引用次数: 0

Corrigendum to “Early-stage flame acceleration in stratified hydrogen-air mixtures: Theory and simulation” [Proc. Combust. Inst. 40 (2024) 105279] “分层氢-空气混合物中早期火焰加速：理论与模拟”的勘误表[燃烧过程]。研究所40 (2024)105279]

IF 5.2 2区工程技术 Q2 ENERGY & FUELS

Proceedings of the Combustion Institute

Pub Date : 2025-01-01 DOI: 10.1016/j.proci.2025.105822

Sébastien Missey , Omar Dounia , Laurent Selle

引用次数: 0

Flame-flame interactions in lean premixed hydrogen-enriched ammonia-air flames at varying pressures 贫富氢氨-空气预混火焰在不同压力下的火焰-火焰相互作用

IF 5.2 2区工程技术 Q2 ENERGY & FUELS

Proceedings of the Combustion Institute

Pub Date : 2025-01-01 DOI: 10.1016/j.proci.2025.105806

Shrey Trivedi , Martin Rieth , Hassan F. Ahmed , Jacqueline H. Chen , R. Stewart Cant

Flame-flame interaction statistics are analyzed using a Direct Numerical Simulation (DNS) dataset for highly turbulent premixed flames in a temporally-evolving shear layer configuration at pressures of 1 atm and 10 atm. The fuel is a blend of ammonia, hydrogen and nitrogen, and the oxidizer is air. The critical point method is used to identify the different types of flame surface topology. Results are obtained for two different and widely-separated instants of time during the development of the flame. These two times correspond to instants with strong flame interaction with sheared turbulence and after the onset of cellular instability. The statistics indicate that there is a change in the distribution of flame-flame interaction events within the flame brush between the two different times. More events occur towards the trailing edge of the flame at the later time, and there is also a change in the type of topology observed. The changes are found to be stronger for the higher pressure case.

利用直接数值模拟（DNS）数据集，分析了1 atm和10 atm压力下高湍流预混火焰在时间演化剪切层配置下的火焰-火焰相互作用统计。燃料是氨、氢和氮的混合物，氧化剂是空气。采用临界点法识别不同类型的火焰表面拓扑结构。在火焰的发展过程中，得到了两个不同的、间隔很宽的时间瞬间的结果。这两个时间对应于与剪切湍流强烈火焰相互作用的瞬间和细胞不稳定开始后的瞬间。统计结果表明，在两个不同的时间内，火焰刷内火焰-火焰相互作用事件的分布发生了变化。在较晚的时间里，更多的事件发生在火焰的后缘，并且观察到的拓扑类型也发生了变化。发现高压情况下的变化更强。

引用次数: 0

Stabilised combustion of lean hydrogen–air mixtures in the presence of silica 贫氢-空气混合物在二氧化硅存在下的稳定燃烧

IF 5.2 2区工程技术 Q2 ENERGY & FUELS

Proceedings of the Combustion Institute

Pub Date : 2025-01-01 DOI: 10.1016/j.proci.2025.105841

Aki Fujinawa, Ewa J. Marek

The urgent need to transition out of our reliance on fossil fuels motivates the development of emission-free combustion technologies. Here we demonstrate a method to burn hydrogen, a fuel that can be produced with green electricity, in a packed bed of silica particles. The presence of silica particles prevents the significant increase in process temperature encountered in gas-flame arrangements, thereby enabling the conversion of hydrogen to heat while mitigating nitrogen oxide emissions. Partial combustion is observed in packed beds of silica particles below the gas-phase ignition temperature, suggesting that a heterogeneous combustion mechanism dominates at low temperatures. Above the gas-phase ignition temperature, silica particles prevent thermal runaway by acting as a heat sink, suppressing the OH

•

radical-producing chain branching reactions, and instead promoting the conversion of hydrogen to water vapour by a mechanism involving the hydroperoxyl intermediate. Radical quenching and recombination reactions on surfaces of silica particles further reduce the availability of free radicals during in-bed combustion. The combustion of hydrogen with solid particles of silica can easily be scaled up using a fluidised configuration, owing to the low cost and wide availability of quartz sand. We present a unique opportunity for the stabilised, nitrogen oxides-free conversion of hydrogen to heat, offering an economical and scalable solution for large-scale industrial heat production with important economic and environmental value.

摆脱对化石燃料依赖的迫切需要促使了无排放燃烧技术的发展。在这里，我们展示了一种燃烧氢的方法，氢是一种可以用绿色电力生产的燃料，在填充的二氧化硅颗粒床上。二氧化硅颗粒的存在防止了在气体-火焰安排中遇到的工艺温度的显着增加，从而使氢转化为热，同时减少氮氧化物的排放。在低于气相点火温度的二氧化硅颗粒填充床中观察到部分燃烧，表明低温下的非均相燃烧机制占主导地位。在气相点火温度以上，二氧化硅颗粒通过充当散热器来防止热失控，抑制OH•自由基产生的链支反应，并通过涉及羟基中间体的机制促进氢向水蒸气的转化。氧化硅颗粒表面的自由基猝灭和复合反应进一步降低了床内燃烧过程中自由基的可用性。由于石英砂的低成本和广泛可用性，氢与固体二氧化硅颗粒的燃烧可以很容易地使用流化配置进行放大。我们为稳定、无氮氧化物的氢转化为热提供了一个独特的机会，为大规模工业热生产提供了一个经济、可扩展的解决方案，具有重要的经济和环境价值。

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引用次数: 0