平面微燃烧室氨/氢-空气预混火焰辐射和能量转换的数值分析

IF 6.7 1区工程技术 Q2 ENERGY & FUELS

Fuel Pub Date : 2025-05-23 DOI:10.1016/j.fuel.2025.135734

Zhongnong Zhang , Nimeti Kalaycı , Chun Lou , Weihua Cai

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引用次数: 0

摘要

本文基于热力学第二定律，对平面微燃烧器中NH3/ h2 -空气预混火焰进行了系统的理论分析，探讨了燃烧机理，并对燃烧效率进行了评价。对三维平面微燃烧室的燃烧过程进行了数值模拟，并在此基础上计算了不同的熵产率和火用通量率。在熵产分析中，利用化学熵产率来还原化学机理，评价各种化学途径和物质的影响。研究了火焰的形态特征（包括火焰的位置、火焰表面的跨度和形状）与化学熵的产生之间的关系。在用能分析中，给出了化学用能通量率、热力用能通量率和辐射用能通量率的分布。计算了不同阶段的能量转换效率（化学转化为热力，热力转化为辐射）。对于火焰中的热辐射，研究了NH3/H2预混火焰中辐射能的传递过程，分析了火焰发出的辐射能的光谱特征。结果表明：该化学反应的不可逆性产生的熵产率为40 ~ 67.5%，是NH3/H2预混火焰熵产的主要来源。NH2是NH3燃烧过程中发生化学反应的重要物质。当当量比为1.0、0.9和0.8时，NH2的影响因子分别达到0.353、0.367和0.273，在所有含氮物质中影响因子最高。热力学到辐射的转换效率（20-30%）低于化学到热力学的转换效率（约75%）。

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Numerical analysis of radiative and energy conversion for ammonia/hydrogen-air premixed flame in a planar micro-combustor

In this paper, we carry out a systemic theoretical analysis, based on the second law thermodynamics, of an NH₃/H₂-air premixed flame in a planar micro-combustor to investigate the mechanism of combustion and to evaluate the combustion efficiency. The combustion process in a 3D planar micro-combustor is simulated numerically, and based on the numerical results, various entropy generation rates and exergy flux rates are calculated. In the entropy generation analysis, the chemical entropy generation rate is used to reduce the chemical mechanism and to evaluate the influence of various chemical pathways and substances. The relationships between the morphological characteristics of the flames, including their locations, the spans and shapes of the flame surfaces, and the generation of chemical entropy, are investigated. In the exergy analysis, the distributions of the chemical exergy flux rate, thermomechanical exergy flux rate and radiative exergy flux rate are given. The efficiencies of energy conversion (chemical to thermomechanical, and thermodynamic to radiation) are calculated for the various stages. For thermal radiation in flames, the transfer process of the radiative exergy in NH₃/H₂ premixed flames is studied, and the spectral characteristics of the radiative exergy emitted by the flames are analysed. The results indicate that the irreversibility of the chemical reaction produces an entropy generation rate of 40–67.5%, which is the main source of entropy generation for NH₃/H₂ premixed flames. NH₂ is an important substance in terms of the chemical reaction in the combustion process of NH₃. At equivalence ratios of 1.0, 0.9 and 0.8, the values of the influence factor for NH₂ reach 0.353, 0.367 and 0.273, respectively, which are the highest for all nitrogen-containing substances. The thermodynamic-to-radiation conversion efficiency (20–30%) is lower than the chemical-to-thermomechanical conversion efficiency (approximately 75%).

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来源期刊

Fuel 工程技术-工程：化工

CiteScore

12.80

自引率

20.30%

发文量

3506

审稿时长

64 days

期刊介绍： The exploration of energy sources remains a critical matter of study. For the past nine decades, fuel has consistently held the forefront in primary research efforts within the field of energy science. This area of investigation encompasses a wide range of subjects, with a particular emphasis on emerging concerns like environmental factors and pollution.