为满足日趋严格的环保法规和减少碳排放的需求，燃气轮机的技术发展呈现出低排放、高参数、多燃料和宽工况灵活运行的趋势。现有的单一旋流贫预混燃烧技术已经不能适应这些新的变化。因此，该文挑选了10种有潜力的先进燃烧技术展开综述，首先简要介绍其原理和发展现状，然后针对燃气轮机未来发展趋势，从技术成熟度、污染物排放等方面分析其应用前景和可行性，并提出下一步需要突破的技术瓶颈和关键问题。在此基础上，提出了一种评价方法，分析和比较各技术的综合性能和实施难易程度，为技术路线和攻关方向的筛选提供参考依据。

Hydrogen is receiving increasing attention as a versatile energy vector to help accelerate the transition to a decarbonised energy future. Gas turbines will continue to play a critical role in providing grid stability and resilience in future low-carbon power systems; however, it is recognised that this role is contingent upon achieving increased thermal efficiencies and the ability to operate on carbon-neutral fuels such as hydrogen. An important consideration in the development of gas turbine combustors capable of operating with pure hydrogen or hydrogen-enriched natural gas are the significant changes in thermoacoustic instability characteristics associated with burning these fuels. This article provides a review of the effects of burning hydrogen on combustion dynamics with focus on swirl-stabilised lean-premixed combustors. Experimental and numerical evidence suggests hydrogen can have either a stabilising or destabilising impact on the dynamic state of a combustor through its influence particularly on flame structure and flame position. Other operational considerations such as the effect of elevated pressure and piloting on combustion dynamics as well as recent developments in micromix burner technology for 100% hydrogen combustion have also been discussed. The insights provided in this review will aid the development of instability mitigation strategies for high hydrogen combustion.

燃烧不稳定性问题广泛出现在各类航空发动机燃烧室内，该问题是火焰非定常热释放和声波充分耦合的结果，发生时伴随着大幅度的压力脉动，严重威胁发动机的稳定工作及结构安全。目前，包括中国在内的各航空发动机研制国家在多数发动机型号的研制过程中，均遇到了严重的燃烧不稳定性问题，且发动机越先进，该问题越复杂且难以解决。在深入认识其发生机理的基础上，对其进行准确预测并设计有效的控制手段，对航空发动机的研制具有重要意义。系统阐述了该问题的研究现状，介绍了燃烧不稳定性问题发生关键，即军用的钝体燃烧加力燃烧室和民用的贫油预混环形燃烧室的非定常流动及火焰响应特征。综述了该问题研究常用的燃烧不稳定性声网络预测分析模型，重点报告了为了耦合考虑燃烧室声软壁面被动控制设计，团队所发展的三维燃烧不稳定性预测控制模型。基于该模型，介绍了壁面声衬参数及布局对燃烧不稳定模态控制效果影响的研究进展，为先进发动机燃烧不稳定性的排故提供技术储备。

The problem of combustion instability widely exists in various types of aero-engine combustion chambers. This problem is the result of the coupling between the unsteady heat release of the flame and acoustic waves. Its occurrence is accompanied by a large pressure pulsation， which seriously threatens the stable operation and structural safety of the engine. At present， all aero-engine development countries have encountered serious combustion instability problems in the development process of most engine models. The more advanced the engine is， the more complex and difficult it is to solve the problem. It is of great significance for the development of aero-engines to accurately predict and design effective control methods based on its occurrence mechanism. The research status of this problem is systematically described. The key factor of the problem is introduced， that is， the unsteady flow and flame response characteristics of the military bluff body combustion afterburner and the civil lean premixed annular combustor. Furthermore， the eigenvalue-based predictive acoustic network models commonly used in the study of this problem are reviewed. The three-dimensional combustion instability prediction model developed by our team is highlighted， which considers the acoustic soft wall control design of the combustion chamber wall. Based on this model， the research progress of the influence of the parameters and layout of the wall acoustic lining on the combustion instability mode is reviewed， providing technical reserves for improving the combustion instability troubleshooting capability.

为明确不同NO_x数值模型对甲烷/空气燃烧NO_x生成特性的适用性和差异性,以射流扩散火焰、旋流预混火焰、燃气轮机燃烧室为研究对象,分析了NO_x后处理模型法、解耦详细反应机理法和附加NO_x输运方程法对甲烷/空气燃烧NO_x生成特性模拟的适用性和差异性。结果表明：火焰后方N₂O的生成量较少,NO₂的生成量极少,NO含量占总NO_x的95.00%以上;NO_x后处理模型法可准确模拟火焰附近的NO_x生成位置和火焰后方的NO_x生成速率,但该模型低估了火焰位置的NO_x生成量和生成速率,并且不能再现火焰锋面附近N₂O浓度先升高后下降的变化规律;附加NO_x输运方程法对火焰锋面处的NO_x生成位置、生成量和生成速率的计算精度最高,但该模型低估了火焰锋面后方的NO_x生成速率;解耦详细反应机理法对NO_x生成特性的预测精度最差。

This review overviews combustion technologies for reduced emissions and better fuel economy in the industrial gas turbine. Lean premixed combustion (LPM) technology is introduced as a low-temperature combustion technique to control NOx emissions. The dry low NOx (DLN) is one of the most promising LPM-based combustors for controlling NOx emissions. However, DLN combustors suffer from limited flame stability, especially under low load (near blowout) operating conditions, in addition to the difficulty of separating CO2 from the exhaust stream for reducing the gas-turbine carbon footprint. Trying to overcome such difficulties, the gas turbine manufacturers developed enhanced-design burners for higher turndown and lower NOx emissions, including the Dual Annular Counter Rotating Swirl (DACRS) and environmental-vortex (EV) burners. The volume of the DACRS combustors is almost twice the conventional burners, which provide ample residence time for complete combustion. The mixing effectiveness is improved in EV-burners resulting in higher flame stability at low load or startup conditions. To widen the operability, control the emissions, and improve the turndown ratio of gas turbine combustors, the concept of flame stratification, i.e., heterogenization of the overall equivalence ratio, was introduced. This technique can widen the stability range of existing LPM flames for industrial applications. Integrating stratified combustion techniques with oxy-fuel combustion technology is a way forward that may result in complete control of gas turbine emissions with a higher operability turndown ratio. The recent developments and challenges toward the application of hydrogen gas turbines are introduced.

The article reviews gas turbine combustion technologies focusing on their current ability to operate with hydrogen enriched natural gas up to 100% H2. The aim is to provide a picture of the most promising fuel-flexible and clean combustion technologies, the object of current research and development. The use of hydrogen in the gas turbine power generation sector is initially motivated, highlighting both its decarbonisation and electric grid stability objectives; moreover, the state-of-the-art of hydrogen-blend gas turbines and their 2024 and 2030 targets are reported in terms of some key performance indicators. Then, the changes in combustion characteristics due to the hydrogen enrichment of natural gas blends are briefly described, from their enhanced reactivity to their pollutant emissions. Finally, gas turbine combustion strategies, both already commercially available (mostly based on aerodynamic flame stabilisation, self-ignition, and staging) or still under development (like the micro-mixing and the exhaust gas recirculation concepts), are described.

通过建立轴向分级燃烧室的化学反应器网络模型，在燃气轮机典型工况下研究第一级与第二级燃烧段之间的燃料分配、流量分配和停留时间分配等因素对NO_x排放的影响。结果表明：在燃烧室出口温度恒定的条件下，减少第一级的燃料分配比例使第二级出口烟气温度高于第一级，调节第二级喷嘴位置来缩短第二级燃烧段的停留时间，可以显著降低NO_x排放；但是当第一级燃烧产物与第二级燃料/空气混合物混合不均匀时，会严重影响分级燃烧的NO_x减排效果。

A chemical reactor network (CRN) model was established for the axially-staged combustor to study the effects of following key staging parameters on the NO_<i>x</i> emission under typical operating conditions of advanced gas turbines, such as the fuel split, residence time split and flow rate split between the two stages. Results show that under constant exit temperature of combustor, the NO_<i>x</i> emission could be reduced significantly when running the second stage hotter than the first one, by splitting more fuels to the second stage, and/or by shortening the residence time in the second stage through adjusting the layout of the second stage nozzles. In addition, poor mixing of the first-stage combustion products with the second stage mixture of fuel and air would remarkably affact the NO_<i>x</i> emission reduction of the staged combustion system.

Excess energy generation from renewables can be conveniently stored as hydrogen for later use as a gas turbine fuel. Also, the strategy to sequestrate CO2 from natural gas (NG) will require gas turbines to run with hydrogen-based fuels. In such scenarios, high temperature low emission combustion of hydrogen is a key requirement for the future gas turbine market. Ansaldo Energia's gas turbines featuring sequential combustion have an intrinsic advantage when it comes to fuel flexibility and in particular hydrogen-based fuels. The sequential combustion system is composed of two complementary combustion stages in series: one premix stage followed by an auto-ignited second stage overcoming the limits of traditional premix combustion systems through a highly effective extra tuning parameter, i.e., the temperature between the first and the second stage. The standard constant pressure sequential combustion (CPSC) system as applied in the GT36 engine is tested, at high pressure, demonstrating that a modified operation concept allows stable combustion with no changes in combustor hardware for the whole range of NG and hydrogen blends. It is shown that in the range from 0% to 70% (vol.) hydrogen, stable combustion is achieved at full nominal exit temperature, i.e., without any derating and thus clearly outperforming other available conventional premixed combustors. Operation between 70% and 100% is possible as well and only requires a mild reduction of the combustor exit temperature. By proving the transferability of the single-can high pressure results to the engine, this paper demonstrates the practicality of operating the Ansaldo Energia GT36 H-Class gas turbine on fuels containing unprecedented concentrations of hydrogen while maintaining excellent performance and low emissions both in terms of NOx and CO2.

To avoid flashback issues of the high-H2 syngas fuel, current syngas turbines usually use nonpremixed combustors, which have high NOx emissions. A promising solution to this dilemma is rich-burn, quick-mix, lean-burn (RQL) combustion, which not only reduces NOx emissions but also mitigates flashback. This paper presents a kinetics modeling study on NOx emissions of a syngas–fueled gas turbine combustor using RQL architecture. The combustor was simulated with a chemical reactor network (CRN) model in chemkin-pro software. The combustion and NOx formation reactions were modeled using a detailed kinetics mechanism that was developed for syngas. Impacts of combustor design/operating parameters on NOx emissions were systematically investigated, including combustor outlet temperature, rich/lean air flow split, and residence time split. The mixing effects in both the rich-burn zone and the quick-mix zone were also investigated. Results show that for an RQL combustor, the NOx emissions initially decrease and then increase with combustor outlet temperature. The leading parameters for NOx control are temperature-dependent. At typical modern gas turbine combustor operating temperatures (e.g., &amp;lt;1890 K), the air flow split is the most effective parameter for NOx control, followed by the mixing at the rich-burn zone. However, as the combustor outlet temperature increases, the impacts of air flow split and mixing in the rich-burn zone on NOx reduction become less pronounced, whereas both the residence time split and the mixing in the quick-mix zone become important.

This paper focuses on the potential use of ammonia as a carbon-free fuel, and covers recent advances in the development of ammonia combustion technology and its underlying chemistry. Fulfilling the COP21 Paris Agreement requires the de-carbonization of energy generation, through utilization of carbon-neutral and overall carbon-free fuels produced from renewable sources. Hydrogen is one of such fuels, which is a potential energy carrier for reducing greenhouse-gas emissions. However, its shipment for long distances and storage for long times present challenges. Ammonia on the other hand, comprises 17.8% of hydrogen by mass and can be produced from renewable hydrogen and nitrogen separated from air. Further more, thermal properties of ammonia are similar to those of propane in terms of boiling temperature and condensation pressure, making it attractive as a hydrogen and energy carrier. Ammonia has been produced and utilized for the past 100 years as a fertilizer, chemical raw material, and refrigerant. Ammonia can be used as a fuel but there are several challenges in ammonia combustion, such as low flammability, high NOx emission, and low radiation intensity. Overcoming these challenges requires further research into ammonia flame dynamics and chemistry. This paper discusses recent successful applications of ammonia fuel, in gas turbines, co-fired with pulverize coal, and in industrial furnaces. These applications have been implemented under the Japanese 'Cross-ministerial Strategic Innovation Promotion Program (SIP): Energy Carriers'. In addition, fundamental aspects of ammonia combustion are discussed including characteristics of laminar premixed flames, counterflow twin-flames, and turbulent premixed flames stabilized by a nozzle burner at high pressure. Furthermore, this paper discusses details of the chemistry of ammonia combustion related to NOx production, processes for reducing NOx, and validation of several ammonia oxidation kinetics models. Finally, LES results for a gas-turbine-like swirl-burner are presented, for the purpose of developing low-NOx single-fuelled ammonia gas turbine combustors. (C) 2019 The Authors. Published by Elsevier Inc. on behalf of The Combustion Institute.