Article
Energy & Fuels
Zinong Zuo, Zhennan Zhu, Kun Liang, Xiuchao Bao, Dongjian Zeng, Lingan Kong
Summary: Diluents decrease adiabatic flame temperature and thermal diffusivity, resulting in decreased laminar burning velocity; carbon dioxide has a stronger inhibitory effect than nitrogen. Flame instability is not sensitive to diluent gas fraction or type.
Article
Energy & Fuels
Jun Cheng, Bo Zhang
Summary: This study investigates the explosion characteristics and flame instability of ammonia-air/oxygen mixtures and provides fundamental research on the combustion characteristics, which can serve as an experimental reference for the development of chemical reaction mechanisms for ammonia combustion in oxygen-rich environments. The results also offer data support for the possibility of using ammonia fuel as a propellant for hypersonic vehicles in the future.
Article
Energy & Fuels
Wenjun Lin, Jinhua Wang, Runze Mao, Weijie Zhang, Hao Xia, Meng Zhang, Zuohua Huang
Summary: In this study, experimental research was conducted to investigate the differential diffusion and turbulence effects on the flame structure when adding DME to a lean premixed CH4/air Bunsen flame. The results showed that DME addition and turbulence can make the flame curvature distribution more symmetrical, with DME having a minor effect on curvature as turbulence intensity increases. Additionally, DME addition decreased turbulent burning velocity, while the interaction between turbulence and differential diffusion effect promoted changes in the flame surface density distribution.
Article
Thermodynamics
Zongming Yu, Yuhua Ai, Yue Wang, Chuanzhi Luo
Summary: The study investigated the thermoacoustic instability of a laminar lean premixed flame in gas turbine combustors through theoretical analysis and numerical simulation, focusing on the autoignition and propagation mechanism of the flame. Results showed that the three-step mechanism could effectively describe the high-temperature chemistry involved in autoignition and flame propagation.
COMBUSTION AND FLAME
(2021)
Article
Chemistry, Physical
Zhiqiang Chen, Yong Jiang
Summary: This study systematically investigated the laminar premixed combustion characteristics of NH3/air flame with various H-2/CO/SYN addition loadings, and found that H-2 has the greatest effects on increasing laminar burning velocities and net heat release rates, while CO significantly improves the adiabatic flame temperatures. The addition of H-2/CO/SYN can accelerate NH3 decomposition rates and promote the generation of radicals, showing a positive linear correlation with laminar burning velocities.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2021)
Article
Chemistry, Physical
Yongseok Choi, Kyu Tae Kim
Summary: To enable reliable lean-premixed gas turbine combustion with pure hydrogen or high hydrogen content fuels, multi-element injector configurations comprising numerous small-scale jet nozzles are required. The integration of large numbers of millimeter-scale injectors in tightly clustered arrays is likely to produce peculiar topological states determined by the collective dynamics of strongly interacting premixed hydrogen flames. Experimental investigation of two different pure hydrogen flame ensembles reveals that the characteristic dimension of a single injector element is the main determinant of the fundamental frequency of self-induced pressure oscillations, and that flame dynamics play a mechanistic role in the growth of higher harmonics, defining the thermoacoustic state of clustered lean-premixed hydrogen flames.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2023)
Article
Thermodynamics
B. Cuenot, F. Shum-Kivan, S. Blanchard
Summary: Modeling turbulent non-premixed combustion is challenging, and this study applies the Thickened Flame concept to diffusion flames, deriving a model suitable for these flames. The results demonstrate the effectiveness of the Thickened Flame concept in combustion modeling and provide an expression for the thickening factor related to mesh coarsening.
COMBUSTION AND FLAME
(2022)
Article
Chemistry, Applied
Youping Li, Yiran Zhang, Reggie Zhan, Zhen Huang, He Lin
Summary: The study found that the addition of NH3 can inhibit the formation of PAH in n-heptane flames, mainly due to competition between NH3 and radicals in fuel decomposition. Therefore, NH3 addition effectively inhibits PAH formation by suppressing the production of C2H2.
FUEL PROCESSING TECHNOLOGY
(2021)
Article
Chemistry, Physical
Du Wang, Changwei Ji, Shuofeng Wang, Jinxin Yang, Zhe Wang
Summary: This study extensively investigated the combustion properties of ammonia/hydrogen/air premixed combustion and found that most properties of ammonia/hydrogen combustion could be comparable to that of hydrocarbon fuels, except for a slightly lower mixture heating value. The NO mole fraction of stoichiometric ammonia/hydrogen could be even lower than that of hydrocarbons. Promising working conditions for ammonia/hydrogen mixtures are phi from 1.0 to 1.05 and alpha from 40% to 60%.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2021)
Article
Energy & Fuels
Yuzhou Cheng, Tai Jin, Kun Luo, Zongyan Li, Haiou Wang, Jianren Fan
Summary: The combustion instability in laminar premixed flames is influenced by flame holder temperature, with different instability modes at different temperatures being affected by flame characteristics, recirculation zones, and acoustic modes. ITA modes affect combustion instability in different ways, either causing intrinsic instability or coupling with acoustic modes to create new instability modes, highlighting the importance of considering ITA modes in the analysis of combustion instability in realistic systems.
Article
Chemistry, Physical
Ksenia N. Osipova, Oleg P. Korobeinichev, Andrey G. Shmakov
Summary: This paper presents experimental data on the flame structure of laminar premixed ammonia and ammonia/hydrogen flames at different equivalence ratios and the laminar flame speed of ammonia/hydrogen flames. Experimental data were compared with modeling results obtained using detailed chemical-kinetic mechanisms of ammonia oxidation. The study shows that slightly rich conditions and increasing pressure can reduce NO formation in ammonia flames.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2021)
Article
Thermodynamics
Yao Liu, Jianguo Tan, Zhengwang Gao, Taiyu Wang, Minggang Wan
Summary: The study investigated the characteristics of chemiluminescence and NOx emissions under different conditions, finding a linear relationship between them, enabling the monitoring of NOx emissions through the chemiluminescence technique.
CASE STUDIES IN THERMAL ENGINEERING
(2021)
Article
Energy & Fuels
Yuxuan Zhao, Enhua Wang, Zhicheng Shi
Summary: The combustion characteristics of kerosene blended with hydrogen in SI engines were numerically analyzed, and it was found that the addition of hydrogen can shorten the ignition delay time and increase the laminar flame speed, which is beneficial for knock suppression.
Article
Energy & Fuels
Shixing Wang, Guoqing Wang, Ayman M. Elbaz, Thibault F. Guiberti, William L. Roberts
Summary: This study focuses on the effects of turbulent intensity, ammonia content, and equivalence ratio on the flame structure and NO emissions of ammonia/methane/air flames, as well as their links to OH-PLIF intensity. It is found that the flame shape is determined by the ammonia content and equivalence ratio, and a unified correlation between turbulent intensity and OH-PLIF intensity is proposed. A new description of the link between NO, OH, and ammonia content is provided, improving the correlation performance.
Article
Thermodynamics
Can Shao, Felipe Campuzano, Yitong Zhai, Haoyi Wang, Wen Zhang, S. Mani Sarathy
Summary: This study investigated particle size distributions and chemical compositions of soot in ethylene-oxygen flames with and without ammonia doping. The results showed that ammonia doping inhibits soot formation and decreases the size and volume fraction of soot particles. This was attributed to the generation of C-N species in ethylene-ammonia flames, which prevented carbon from participating in soot precursor formation.
COMBUSTION AND FLAME
(2022)
Article
Green & Sustainable Science & Technology
Cameron Bracken, Nathalie Voisin, Casey D. Burleyson, Allison M. Campbell, Z. Jason Hou, Daniel Broman
Summary: This study presents a methodology and dataset for examining compound wind and solar energy droughts, as well as the first standardized benchmark of energy droughts across the Continental United States (CONUS) for a 2020 infrastructure. The results show that compound wind and solar droughts have distinct spatial and temporal patterns across the CONUS, and the characteristics of energy droughts are regional. The study also finds that compound high load events occur more often during compound wind and solar droughts than expected.
Article
Green & Sustainable Science & Technology
Ning Zhang, Yanghao Yu, Jiawei Wu, Ershun Du, Shuming Zhang, Jinyu Xiao
Summary: This paper provides insights into the optimal configuration of CSP plants with different penetrations of wind power by proposing an unconstrained optimization model. The results suggest that large solar multiples and TES are preferred in order to maximize profit, especially when combined with high penetrations of wind and photovoltaic plants. Additionally, the study demonstrates the economy and feasibility of installing electric heaters (EH) in CSP plants, which show a linear correlation with the penetration of variable energy resources.
Article
Green & Sustainable Science & Technology
M. Szubel, K. Papis-Fraczek, S. Podlasek
Article
Green & Sustainable Science & Technology
J. Silva, J. C. Goncalves, C. Rocha, J. Vilaca, L. M. Madeira
Summary: This study investigated the methanation of CO2 in biogas and compared two different methanation reactors. The results showed that the cooled reactor without CO2 separation achieved a CO2 conversion rate of 91.8%, while the adiabatic reactors achieved conversion rates of 59.6% and 67.2%, resulting in an overall conversion rate of 93.0%. Economic analysis revealed negative net present worth values, indicating the need for government monetary incentives.
Article
Green & Sustainable Science & Technology
Yang Liu, Yonglan Xi, Xiaomei Ye, Yingpeng Zhang, Chengcheng Wang, Zhaoyan Jia, Chunhui Cao, Ting Han, Jing Du, Xiangping Kong, Zhongbing Chen
Summary: This study investigated the effect of using nanofiber membrane composites containing Prussian blue-like compound nanoparticles (PNPs) to relieve ammonia nitrogen inhibition of rural organic household waste during high-solid anaerobic digestion and increase methane production. The results showed that adding NMCs with 15% PNPs can lower the concentrations of volatile fatty acids and ammonia nitrogen, and increase methane yield.
Article
Green & Sustainable Science & Technology
Zhong Ge, Xiaodong Wang, Jian Li, Jian Xu, Jianbin Xie, Zhiyong Xie, Ruiqu Ma
Summary: This study evaluates the thermodynamic, exergy, and economic performance of a double-stage organic flash cycle (DOFC) using ten eco-friendly hydrofluoroolefins. The influences of key parameters on performance are analyzed, and the advantages of DOFC over single-stage type are quantified.
Article
Green & Sustainable Science & Technology
Nicolas Kirchner-Bossi, Fernando Porte-Agel
Summary: This study investigates the optimization of power density in wind farms and its sensitivity to the available area size. A novel genetic algorithm (PDGA) is introduced to optimize power density and turbine layout. The results show that the PDGA-driven solutions significantly reduce the levelized cost of energy (LCOE) compared to the default layout, and exhibit a convex relationship between area and LCOE or power density.
Article
Green & Sustainable Science & Technology
Chunxiao Zhang, Dongdong Li, Lin Wang, Qingpo Yang, Yutao Guo, Wei Zhang, Chao Shen, Jihong Pu
Summary: In this study, a novel reversible liquid-filled energy-saving window that effectively regulates indoor solar radiation heat gain is proposed. Experimental results show that this window can effectively reduce indoor temperature during both summer and winter seasons, while having minimal impact on indoor illuminance.
Article
Green & Sustainable Science & Technology
Alessandro L. Aguiar, Martinho Marta-Almeida, Mauro Cirano, Janini Pereira, Leticia Cotrim da Cunha
Summary: This study analyzed the Brazilian Equatorial Shelf using a high-resolution ocean model and found significant tidal variations in the area. Several hypothetical barrages were proposed with higher annual power generation than existing barrages. The study also evaluated the installation effort of these barrages.
Article
Green & Sustainable Science & Technology
Francesco Superchi, Nathan Giovannini, Antonis Moustakis, George Pechlivanoglou, Alessandro Bianchini
Summary: This study focuses on the optimization of a hybrid power station on the Tilos island in Greece, aiming to increase energy export and revenue by optimizing energy fluxes. Different scenarios are proposed to examine the impact of different agreements with the grid operator on the optimal solution.
Article
Green & Sustainable Science & Technology
Peimaneh Shirazi, Amirmohammad Behzadi, Pouria Ahmadi, Sasan Sadrizadeh
Summary: This research presents two novel energy production/storage/usage systems to reduce energy consumption and environmental effects in buildings. A biomass-fired model and a solar-driven system integrated with photovoltaic thermal (PVT) panels and a heat pump were designed and assessed. The results indicate that the solar-based system has an acceptable energy cost and the PVT-based system with a heat pump is environmentally superior. The biomass-fired system shows excellent efficiency.
Article
Green & Sustainable Science & Technology
Zihao Qi, Yingling Cai, Yunxiang Cui
Summary: This study aims to investigate the operational characteristics of the solar-ground source heat pump system (SGSHPS) in Shanghai under different operation modes. It concludes that tandem operation mode 1 is the optimal mode for winter operation in terms of energy efficiency.
Article
Green & Sustainable Science & Technology
L. Bartolucci, S. Cordiner, A. Di Carlo, A. Gallifuoco, P. Mele, V. Mulone
Summary: Spent coffee grounds are a valuable biogenic waste that can be used as a source of biofuels and valuable chemicals through pyrolysis and solvent extraction processes. The study found that heavy organic bio-oil derived from coffee grounds can be used as a carbon-rich biofuel, while solvent extraction can extract xantines and p-benzoquinone, which are important chemicals for various industries. The results highlight the promising potential of solvent extraction in improving the economic viability of coffee grounds pyrolysis-based biorefineries.
Article
Green & Sustainable Science & Technology
Luiza de Queiroz Correa, Diego Bagnis, Pedro Rabelo Melo Franco, Esly Ferreira da Costa Junior, Andrea Oliveira Souza da Costa
Summary: Building-integrated photovoltaics, especially organic solar technology, are important for reducing greenhouse gas emissions in the building sector. This study analyzed the performance of organic panels laminated in glass in a vertical installation in Latin America. Results showed that glass lamination and vertical orientation preserved the panels' performance and led to higher energy generation in winter.
Article
Green & Sustainable Science & Technology
Zhipei Hu, Shuo Jiang, Zhigao Sun, Jun Li
Summary: This study proposes innovative fin arrangements to enhance the thermal performance of latent heat storage units. Through optimization of fin distribution and prediction of transient melting behaviors, it is found that fin structures significantly influence heat transfer characteristics and melting behaviors.