Proceedings of the Combustion Institute最新文献

{"title":"Experimental investigation of air-fuel equivalence ratio effects on advanced dual-fuel ammonia/diesel combustion on a single-cylinder medium-duty diesel engine at high load","authors":"Daanish S. Tyrewala,&nbsp;Brian C. Kaul,&nbsp;Scott J. Curran,&nbsp;Derek A. Splitter","doi":"10.1016/j.proci.2025.105794","DOIUrl":"10.1016/j.proci.2025.105794","url":null,"abstract":"<div><div>Ammonia (NH₃) has garnered significant interest as an alternative fuel for meeting international emissions reduction mandates in sectors with high weight and distance requirements, such as shipping. Technical barriers and unanswered questions remain on the combustion strategies that can maximize ammonia utilization and minimize emissions. Prior research studies at the US Department of Energy’s Oak Ridge National Laboratory have shown strong performance with NH₃ under dual-fuel mode using conventional diesel combustion (CDC) manifold air pressure settings. Diesel airflow was initially used to simplify retrofitting (no turbocharger modification), which resulted in air-fuel equivalence ratios (<em>λ</em>) greater than 1.5. To characterize potential improvements in dual-fuel NH₃ combustion performance at richer in-cylinder conditions, a global <em>λ</em> sweep compared the use of early (E-pilot) and late (L-pilot) single diesel injections. The experiments were conducted at 1200 RPM and 12.8 ± 0.2 bar (75 % load), and <em>λ</em> was varied by decreasing the commanded air flow to the engine at greater than 90 % ammonia energy substitution level. A diesel injection timing sweep was conducted for both the injection strategies at fixed <em>λ</em>, and the timing with the lowest engine-out N₂O emissions was identified. The results indicated an optimal balance between CO_2,eq and thermal efficiency benefits both E-pilot and l-pilot injection strategy cases compared with CDC at a <em>λ</em> of 1.4. The indicated nitrogen-based emissions exhibited a strong correlation to the ratio of CA5–50 and ignition delay for l-pilot, but no apparent trend emerged for the E-pilot injection strategy at the tested boundary conditions.</div></div>","PeriodicalId":408,"journal":{"name":"Proceedings of the Combustion Institute","volume":"41 ","pages":"Article 105794"},"PeriodicalIF":5.2,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144841804","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tangential diffusion effects in thermodiffusively unstable ammonia/hydrogen/nitrogen-air laminar premixed flames","authors":"Sydney L. Rzepka,&nbsp;Katie VanderKam,&nbsp;Michael E. Mueller","doi":"10.1016/j.proci.2025.105804","DOIUrl":"10.1016/j.proci.2025.105804","url":null,"abstract":"<div><div>Partially cracked ammonia is a promising hydrogen-carrying fuel with logistical advantages compared to pure hydrogen. However, like hydrogen-air premixed flames, under fuel-lean conditions, ammonia/hydrogen/nitrogen-air premixed flames can be thermodiffusively unstable. These instabilities affect the flame propagation speeds as well as the local formation of nitrogen oxides and nitrous oxide (reactive nitrogen emissions). To assess the viability of partially cracked ammonia as a zero-carbon fuel, understanding and ultimately modeling these pollutants in thermodiffusively unstable flames is critical. In this work, detailed two-dimensional simulations of laminar premixed planar flames were conducted to understand the development of thermodiffusive instabilities in flames of ammonia/hydrogen/nitrogen mixtures and air. The degree of ammonia cracking was varied to understand the influence of fuel composition on the instability behavior and subsequent formation of nitrogen oxides and nitrous oxide. The detailed simulation results exhibit considerable differential diffusion effects and regions of increased and decreased reactive nitrogen emissions corresponding to local flame curvature. The databases from these detailed simulations were then used to evaluate a premixed manifold model. Manifold models significantly decrease computational cost by mapping the high-dimensional thermochemical state to a lower-dimensional manifold. A premixed manifold model is considered that includes differential diffusion and flame curvature. However, analysis of the databases from these detailed simulations revealed a very strong effect of transport orthogonal to the progress variable gradient, that is, tangential diffusion. Direct tangential diffusion effects are actually stronger for less cracked mixtures due to the larger flame thickness of flames with more ammonia content. For pollutants, direct tangential diffusion effects are important for all cracking ratios, and the existing formulation of the manifold model cannot accurately predict these species. Furthermore, indirect effects of tangential diffusion on pollutants through the local radical pool and equivalence ratio also influence pollutants and are apparently stronger for the higher cracking ratio. Implications for manifold modeling are discussed, and a generally applicable strategy for predicting pollutant mass fractions in partially cracked ammonia flames must directly model tangential diffusion effects rather than rely only a mixture fraction variable to account for only indirect tangential diffusion effects that are most important for fuels containing purely or mostly hydrogen.</div></div>","PeriodicalId":408,"journal":{"name":"Proceedings of the Combustion Institute","volume":"41 ","pages":"Article 105804"},"PeriodicalIF":5.2,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145044043","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Understanding the impact of cycloalkane additives on the combustion of HEFA jet fuel","authors":"Alka Panda ,&nbsp;Andrew Klingberg ,&nbsp;Ronald K. Hanson","doi":"10.1016/j.proci.2025.105803","DOIUrl":"10.1016/j.proci.2025.105803","url":null,"abstract":"&lt;div&gt;&lt;div&gt;Drop-in biofuels, such as Hydroprocessed Esters and Fatty Acids (HEFA), are designed to deliver performance comparable to petroleum-based jet fuels without requiring modifications to existing aircraft engines. These biofuels, which are primarily n- and isoalkanes, have been certified by ASTM for use in blends of up to 50% with conventional Jet A to take advantage of the physical properties of cycloalkanes and aromatics. Cycloalkanes and aromatics are integral components of conventional jet fuels, contributing to desirable physical and combustion properties. However, aromatics are both carcinogenic and major precursors to soot formation, prompting the need for safer and more sustainable alternatives. Bio-derived cycloalkanes have emerged as promising aromatic substitutes, offering comparable fuel properties while mitigating environmental and health risks. HEFA fuels provide an ideal platform for investigating how variations in cycloalkane structures (e.g., monosubstituted, polysubstituted, ring size) uniquely influence fuel reactivity at engine relevant conditions. While the physical properties of cycloalkanes blended with Jet A have been reported in the literature, this study examines the impact of cycloalkane additives on the formation of stable intermediates during HEFA pyrolysis. Combustion studies of jet fuels have shown that larger hydrocarbon molecules undergo pyrolysis to form stable intermediates, such as methane, ethylene, and &lt;span&gt;&lt;math&gt;&lt;mo&gt;&gt;&lt;/mo&gt;&lt;/math&gt;&lt;/span&gt;C2 alkenes. As these intermediates govern the oxidation of the fuel, measuring their time histories and yields provides insight into the fuel reactivity at engine relevant conditions and supports the development of combustion models. Shock tube experiments were conducted to study the pyrolysis of HEFA blends with bio-derived cycloalkanes such as 1,4 dimethylcyclooctane, p-menthane, and n-butylcyclohexane. Multiwavelength laser absorption spectroscopy (LAS) was employed to measure the time-resolved evolution of the stable pyrolysis products. All three cycloalkanes have the same carbon number, allowing for a direct comparison of how structural differences influence the formation of pyrolysis products. Blends containing 30% cycloalkanes by volume in HEFA were analyzed in experiments utilizing 1% fuel/argon test mixtures at a nominal pressure of 2 atm over the temperature range of 1150–1450 K. Additionally, ignition delay times were measured for stoichiometric mixtures for HEFA and cycloalkane blends with oxygen at a nominal pressure of 2 atm over a temperature range of 1200–1400 K. These ignition delay times were used to compare the effect of blending on global combustion behavior. These results suggest that the addition of bio-derived cycloalkanes, which improve the energy density of jet fuels, do not negatively impact the combustion performance of HEFA. Hence, the comparative performance against aromatics should ultimately guide the selection of the most suitable cycl","PeriodicalId":408,"journal":{"name":"Proceedings of the Combustion Institute","volume":"41 ","pages":"Article 105803"},"PeriodicalIF":5.2,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144810146","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhanced catalytic upgrading of biomass wastes pyrolysis vapors over Ni-Co modified HZSM-5 catalyst derived from spent ternary lithium-ion batteries","authors":"Xianqing Zhu ,&nbsp;Liping Wu ,&nbsp;Mian Xu ,&nbsp;Zhipeng Shi ,&nbsp;Xuhui Jiang ,&nbsp;Yun Huang ,&nbsp;Ao Xia ,&nbsp;Jun Li ,&nbsp;Xun Zhu ,&nbsp;Qiang Liao","doi":"10.1016/j.proci.2025.105853","DOIUrl":"10.1016/j.proci.2025.105853","url":null,"abstract":"<div><div>Spent ternary lithium-ion batteries (NCM) are rich in catalytically active transition metals (such as Ni and Co) and have high potential for constructing a catalyst used for the catalytic reforming of biomass pyrolysis volatiles. Therefore, in this study, a novel Ni-Co bimetallic catalyst (MPyNCM/HZSM-5) was fabricated by simultaneously recovering the Ni and Co components from the magnetic components of pyrolysis products of spent NCM (MPyNCM) and loading them on HZSM-5 support. The catalytic reforming performance and mechanism of MPyNCM/HZSM-5 for wheat straw (WS) pyrolysis volatiles were explored for the first time. The results showed that the MPyNCM/HZSM-5 catalyst had a mesoporous structure (average pore size around 5 nm), with the uniform distribution of the active metals Ni and Co on its surface. The MPyNCM/HZSM-5 catalytic reforming had the highest syngas yield, H₂ yield and H₂ concentration, with the H₂ yield reaching 1.19 mmol/g WS and 1.38 times higher than that of the HZSM-5 support. In addition, the MPyNCM/HZSM-5 significantly boosted the generation of aromatic hydrocarbons compounds and reduced the oxygen content of the obtained bio-oils, with the content of aromatic hydrocarbons reaching 29.36 %, which was 48.6 % higher than that of the HZSM-5 support. The synergistic effect between the Ni and Co metals made MPyNCM/HZSM-5 have comparable acid sites amount, high-temperature oxygen defects and reducibility to those of the Ni-Co/HZSM-5 catalysts. These chemical properties jointly promoted the deoxygenation and aromatization reactions of volatile macromolecules under MPyNCM/HZSM-5 catalysis. This study provides a novel approach to constructing a highly efficient catalyst from spent lithium-ion batteries for catalytic pyrolysis of biomass.</div></div>","PeriodicalId":408,"journal":{"name":"Proceedings of the Combustion Institute","volume":"41 ","pages":"Article 105853"},"PeriodicalIF":5.2,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145104310","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Detailed Modeling of Flame-Wall-Interactions under the influence of phosphorous-containing Flame Retardants and development of a reduced kinetic model","authors":"Vanessa Stegmayer,&nbsp;Ulrich Maas,&nbsp;Christina Strassacker","doi":"10.1016/j.proci.2025.105833","DOIUrl":"10.1016/j.proci.2025.105833","url":null,"abstract":"<div><div>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.</div></div>","PeriodicalId":408,"journal":{"name":"Proceedings of the Combustion Institute","volume":"41 ","pages":"Article 105833"},"PeriodicalIF":5.2,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145104441","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental study on combustion and emission characteristics of an ammonia-diesel dual-fuel engine under single and double injection strategies","authors":"Shouzhen Zhang,&nbsp;Qinglong Tang,&nbsp;Rui Yang,&nbsp;Haifeng Liu,&nbsp;Mingfa Yao","doi":"10.1016/j.proci.2025.105872","DOIUrl":"10.1016/j.proci.2025.105872","url":null,"abstract":"<div><div>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.</div></div>","PeriodicalId":408,"journal":{"name":"Proceedings of the Combustion Institute","volume":"41 ","pages":"Article 105872"},"PeriodicalIF":5.2,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145154430","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A shock tube study of chaperon efficiencies for the NH3 + M → NH2 + H + M reaction during ammonia pyrolysis","authors":"Padmanabha Prasanna Simha,&nbsp;Taylor M. Rault,&nbsp;Sean Clees,&nbsp;Jesse W. Streicher,&nbsp;Christopher L. Strand,&nbsp;Ronald K. Hanson","doi":"10.1016/j.proci.2025.105797","DOIUrl":"10.1016/j.proci.2025.105797","url":null,"abstract":"<div><div>Ammonia (NH₃) pyrolysis behind reflected shock waves was studied using laser absorption spectroscopy. Experimental measurements of the rate coefficient for the <figure><img></figure> forward reaction were obtained by targeting the NH radical. The mole fraction of the NH radical is uniquely sensitive to the rate coefficient of the <figure><img></figure> reaction under dilute conditions since it is slower than other NH producing reactions. The NH₃ mole fraction prior to the arrival of the shock wave was measured using a scanned-wavelength infrared laser absorption diagnostic at <span><math><mrow><mn>10</mn><mo>.</mo><mn>35</mn><mspace></mspace><mi>μ</mi><mi>m</mi></mrow></math></span>. A fixed-wavelength ultraviolet laser absorption diagnostic at 336.0998 nm was used to obtain the time history of NH after the passage of the reflected shock. Chemical kinetic model rates were tuned to obtain the best fit to the experimental results. Experiments in a temperature range of 1900 K to 2300 K were conducted with ammonia diluted in argon (Ar), nitrogen (N₂) and hydrogen (H₂) at a pressure of 1 atm. Results of experiments with ammonia diluted in Ar agree with current chemical kinetic models for ammonia pyrolysis. The chaperon (third-body) efficiencies of N₂ and H₂ relative to Ar were obtained. When using a linear mixture rule, N₂ and H₂ are seen to have chaperon efficiencies of 5.2 and 4.4 relative to Ar. These are the first direct measurements of chaperon efficiencies of N₂ and H₂ relative to Ar for this reaction at high temperatures.</div></div>","PeriodicalId":408,"journal":{"name":"Proceedings of the Combustion Institute","volume":"41 ","pages":"Article 105797"},"PeriodicalIF":5.2,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144852893","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Corrigendum to “Early-stage flame acceleration in stratified hydrogen-air mixtures: Theory and simulation” [Proc. Combust. Inst. 40 (2024) 105279]","authors":"Sébastien Missey ,&nbsp;Omar Dounia ,&nbsp;Laurent Selle","doi":"10.1016/j.proci.2025.105822","DOIUrl":"10.1016/j.proci.2025.105822","url":null,"abstract":"","PeriodicalId":408,"journal":{"name":"Proceedings of the Combustion Institute","volume":"41 ","pages":"Article 105822"},"PeriodicalIF":5.2,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145018801","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Flame-flame interactions in lean premixed hydrogen-enriched ammonia-air flames at varying pressures","authors":"Shrey Trivedi ,&nbsp;Martin Rieth ,&nbsp;Hassan F. Ahmed ,&nbsp;Jacqueline H. Chen ,&nbsp;R. Stewart Cant","doi":"10.1016/j.proci.2025.105806","DOIUrl":"10.1016/j.proci.2025.105806","url":null,"abstract":"<div><div>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.</div></div>","PeriodicalId":408,"journal":{"name":"Proceedings of the Combustion Institute","volume":"41 ","pages":"Article 105806"},"PeriodicalIF":5.2,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145018804","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Techno-economic analysis of deep peaking for hydrogen co-firing in a 300 MWe subcritical power plant with hydrogen production from valley electricity","authors":"Tiantian Wang ,&nbsp;Jinwei Sun ,&nbsp;Fuqi Yuan ,&nbsp;Mingye Yang ,&nbsp;Yang Zhang ,&nbsp;Fuyuan Yang ,&nbsp;Minggao Ouyang","doi":"10.1016/j.proci.2025.105839","DOIUrl":"10.1016/j.proci.2025.105839","url":null,"abstract":"<div><div>As the proportion of renewable power generation increases annually, thermal power plants are supposed to operate in deep peaking with high flexibility to balance power supply and power demand as well as ensure grid security. Hydrogen co-firing in thermal power plants is one of the promising approaches to maintaining stable combustion during deep peaking periods, improving peak capacity, and reducing carbon emissions. This paper numerically investigated the thermodynamic performance of deep peaking at 30 % and 20 % heating loads for hydrogen co-firing in a 300 MWe subcritical power plant using the Aspen Plus model and conducted an economic analysis of four scenarios of boiler deep peaking and hydrogen production from valley electricity. The results show that as the hydrogen blending heat ratio increases from 0 % to 15 % with the constant total excess air ratio of 1.15 at 30 % heating load, the boiler thermal efficiency increases from 91.13 % to 92.05 %, the standard coal consumption decreases from 395 g/kWh to 331 g/kWh, and the CO₂ emission per unit of fuel heat input also drops from 132.52 g/MJ to 112.55 g/MJ. If the boiler heating load is further adjusted to 20 %, hydrogen blending and oxygen enrichment can also improve the theoretical combustion temperature and boiler efficiency, as well as save coal and reduce carbon emissions. Regarding the economic analysis, the prices of standard coal and electrolyzers are two key factors affecting the payback time. As the capacity of electrolyzers decreases from 60 MW in Scenario 2 to 20 MW in Scenario 4, the payback time drops from 10.45 years to 3.63 years. In the meantime, the hydrogen blending heat ratio also decreases from 15 % to 5 % at 20 % heating load. There exists a tradeoff between a high hydrogen blending ratio (which means more stable combustion at low heating loads) and a short payback time.</div></div>","PeriodicalId":408,"journal":{"name":"Proceedings of the Combustion Institute","volume":"41 ","pages":"Article 105839"},"PeriodicalIF":5.2,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145104549","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}