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
Chemistry, Physical
Jordan A. C. Kildare, Michael J. Evans, Douglas B. Proud, Rey Chin, Zhao Tian, Paul R. Medwell
Summary: The elevated temperature of hydrogen combustion increases the formation of thermal NOx. MILD combustion is known to reduce NOx emissions and increase thermal efficiency. Pressure has a greater influence on the kinetics of MILD combustion when the oxygen content is reduced.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2023)
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
Thermodynamics
Xing Li, Shengrong Xie, Jing Zhang, Tao Li, Xiaohan Wang
Summary: The experimental study compared the combustion characteristics of CH4/CO2 and CH4/N-2 non-premixed jet flames, showing that CO2 dilution leads to higher lift-off heights and lower blowout limits in turbulent flames. Additionally, elevated air temperature significantly increases the range of stable lifted flames. Pre-mixed flame models were used to analyze liftoff heights and blowout velocities, revealing a linear relationship between non-dimensional liftoff height and fuel jet velocity, as well as between non-dimensional blowout velocity and Reynolds number.
Article
Energy & Fuels
Chinonso Ezenwajiaku, Midhat Talibi, Ramanarayanan Balachandran
Summary: This study focuses on the formation and growth characteristics of polycyclic aromatic hydrocarbons (PAHs) in inverse diffusion flames of various hydrocarbon fuels enriched with H-2. The results show that only the addition of H-2 to CH4 significantly reduces PAH concentrations as the flame length increases. Additionally, the growth rate of PAHs remains relatively stable regardless of the fuel bonding, molecular structure, and H:C ratio.
Article
Energy & Fuels
Tao Shu, Yuan Xue, Zijun Zhou, Zhuyin Ren
Summary: Experimental investigation of flame properties in ammonia/methane/air mixtures shows significant influence of gas composition and pressure on flame speeds and flammability limits. Linear correlation between flame speed and methane volume fraction is observed, with accurate prediction using Okafor et al. mechanism.
Article
Thermodynamics
S. Zitouni, P. Brequigny, C. Mounaim-Rousselle
Summary: The use of Ammonia (NH3) and blends with either Methane (CH4) or Hydrogen (H2) are potential solutions for decarbonising energy systems. Flame speed and Markstein length were determined using an outwardly propagating spherical flame configuration to study the combustion characteristics of NH3 blends.
COMBUSTION AND FLAME
(2023)
Article
Thermodynamics
Ki Sung Jung, Seung Ook Kim, Suk Ho Chung, Chun Sang Yoo
Summary: The characteristics and stabilization mechanisms of autoignited laminar lifted n-heptane jet flames in heated coflow air were investigated through numerical simulations. The study found that autoignition of lean mixtures plays a critical role in stabilizing lifted flames with the MILD combustion mode, and different flame forms can be stabilized depending on inlet temperature and fuel jet velocity. A flame regime diagram was constructed to summarize the flame structures and stabilization mechanisms.
COMBUSTION AND FLAME
(2021)
Article
Energy & Fuels
Zhe Wang, Changwei Ji, Du Wang, Ruifeng Hou, Tianyue Zhang, Shuofeng Wang
Summary: Adding dissociated ammonia can improve the combustion properties of NH3, but may slightly reduce combustion efficiency. Markstein length, heat release reactions, and NO formation are related to the dissociating degree under different conditions.
Article
Thermodynamics
Sayed Mehrdad Bathaei, Mohammad Parsa Ghofrani Maab, Golnaz Zarabian Ghaeini, Mirae Kim, Javad Abolfazli Esfahani, Kyung Chun Kim
Summary: A numerical investigation was conducted to study the characteristics of N2-diluted ammonia combustion in a counterflow diffusion configuration with an elevated oxidizer temperature. The effect of different combustion regimes on ammonia combustion was examined, and specific working conditions for each regime were identified. The results showed that a high dilution of at least 0.8 is required for MILD combustion of ammonia, and the heat release rate, temperature, and species composition were enhanced with combustion regime transition, indicating favorable combustion characteristics in terms of stability and emissions in HiTAC and MILD regimes.
THERMAL SCIENCE AND ENGINEERING PROGRESS
(2023)
Article
Thermodynamics
Krishna Prasad Shrestha, Charles Lhuillier, Amanda Alves Barbosa, Pierre Brequigny, Francesco Contino, Christine Mounaim-Rousselle, Lars Seidel, Fabian Mauss
Summary: This study experimentally investigated the laminar flame speeds of ammonia and ammonia-hydrogen blends under different temperature, pressure, and oxygen content conditions, and developed a new kinetic model for predicting the oxidation mechanisms, considering the formation and reduction of nitrogen oxides. The results showed that the laminar flame speed increases with increasing initial temperature, fuel hydrogen content, or oxidizer oxygen content, but decreases with increasing initial pressure. The proposed kinetic model predicts the same trends as experiments and highlights the importance of N2H2 formation under rich conditions.
PROCEEDINGS OF THE COMBUSTION INSTITUTE
(2021)
Article
Thermodynamics
Sophie Colson, Manuel Kuhni, Akihiro Hayakawa, Hideaki Kobayashi, Cedric Galizzi, Dany Escudie
Summary: Ammonia is a promising alternative fuel for CO 2 emission reduction, especially in existing facilities running on natural gas. This study focuses on ammonia/methane blend fuels and investigates the effect of ammonia on methane jet flame stabilization. The research highlights the impact of ammonia addition on flame position, heat transfer, and the transition between different stabilization regimes.
COMBUSTION AND FLAME
(2021)
Article
Thermodynamics
Sophie Colson, Manuel Kuhni, Cedric Galizzi, Dany Escudie, Hideaki Kobayashi
Summary: This study investigates the effects of ammonia addition on conventional fuels flame stabilization. It is found that ammonia addition leads to a sharp reduction in the stabilization domain and the flame cannot be stabilized. Additionally, an increase in the coflow velocity results in a decrease in the re-attachment velocity of the flame.
COMBUSTION SCIENCE AND TECHNOLOGY
(2022)
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
Thermodynamics
Mino Woo, Byung Chul Choi
Summary: The study focused on the formation characteristics of nitrogen oxides in ammonia-added methane flames, where the fast N-related reactions were found to significantly influence the predicted fuel-NO formation trends with increases in oxygen concentration in the oxidizer.
Article
Thermodynamics
Yong Cheng, Fukai Song, Lei Fu, Saishuai Dai, Zhiming Yuan, Atilla Incecik
Summary: This paper investigates the accessibility of wave energy absorption by a dual-pontoon floating breakwater integrated with hybrid-type wave energy converters (WECs) and proposes a hydraulic-pneumatic complementary energy extraction method. The performance of the system is validated through experiments and comparative analysis.
Article
Thermodynamics
Jing Gao, Chao Wang, Zhanwu Wang, Jin Lin, Runkai Zhang, Xin Wu, Guangyin Xu, Zhenfeng Wang
Summary: This study aims to establish a new integrated method for biomass cogeneration project site selection, with a focus on the application of the model in Henan Province. By integrating Geographic Information System and Multiple Criterion Decision Making methods, the study conducts site selection in two stages, providing a theoretical reference for the construction of biomass cogeneration projects.
Article
Thermodynamics
Mert Temiz, Ibrahim Dincer
Summary: The current study presents a hybrid small modular nuclear reactor and solar-based system for sustainable communities, integrating floating and bifacial photovoltaic arrays with a small modular reactor. The system efficiently generates power, hydrogen, ammonia, freshwater, and heat for residential, agricultural, and aquaculture facilities. Thermodynamic analysis shows high energy and exergy efficiencies, as well as large-scale ammonia production meeting the needs of metropolitan areas. The hybridization of nuclear and solar technologies offers advantages of reliability, environmental friendliness, and cost efficiency compared to renewable-alone and fossil-based systems.
Editorial Material
Thermodynamics
Wojciech Stanek, Wojciech Adamczyk
Article
Thermodynamics
Desheng Xu, Yanfeng Li, Tianmei Du, Hua Zhong, Youbo Huang, Lei Li, Xiangling Duanmu
Summary: This study investigates the optimization of hybrid mechanical-natural ventilation for smoke control in complex metro stations. The results show that atrium fires are more significantly impacted by outdoor temperature variations compared to concourse/platform fires. The gathered high-temperature smoke inside the atrium can reach up to 900 K under a 5 MW train fire energy release. The findings provide crucial engineering insights into integrating weather data and adaptable ventilation protocols for smoke prevention/mitigation.
Article
Thermodynamics
Da Guo, Heping Xie, Mingzhong Gao, Jianan Li, Zhiqiang He, Ling Chen, Cong Li, Le Zhao, Dingming Wang, Yiwei Zhang, Xin Fang, Guikang Liu, Zhongya Zhou, Lin Dai
Summary: This study proposes a new in-situ pressure-preserved coring tool and elaborates its pressure-preserving mechanism. The experimental and field test results demonstrate that this tool has a high pressure-preservation capability and can maintain a stable pressure in deep wells. This study provides a theoretical framework and design standards for the development of similar technologies.
Article
Thermodynamics
Aolin Lai, Qunwei Wang
Summary: This study assesses the impact of China's de-capacity policy on renewable energy development efficiency (REDE) using the Global-MSBM model and the difference-in-differences method. The findings indicate that the policy significantly enhances REDE, promoting technological advancements and marketization. Moreover, regions with stricter environmental regulations experience a higher impact.
Article
Thermodynamics
Mostafa Ghasemi, Hegazy Rezk
Summary: This study utilizes fuzzy modeling and optimization to enhance the performance of microbial fuel cells (MFCs). By simulating and analyzing experimental data sets, the ideal parameter values for increasing power density, COD elimination, and coulombic efficiency were determined. The results demonstrate that the fuzzy model and optimization methods can significantly improve the performance of MFCs.
Article
Thermodynamics
Zhang Ruan, Lianzhong Huang, Kai Wang, Ranqi Ma, Zhongyi Wang, Rui Zhang, Haoyang Zhao, Cong Wang
Summary: This paper proposes a grey box model for fuel consumption prediction of wing-diesel hybrid vessels based on feature construction. By using both parallel and series grey box modeling methods and six machine learning algorithms, twelve combinations of prediction models are established. A feature construction method based on the aerodynamic performance of the wing and the energy relationship of the hybrid system is introduced. The best combination is obtained by considering the root mean square error, and it shows improved accuracy compared to the white box model. The proposed grey box model can accurately predict the daily fuel consumption of wing-diesel hybrid vessels, contributing to operational optimization and the greenization and decarbonization of the shipping industry.
Article
Thermodynamics
Huayi Chang, Nico Heerink, Junbiao Zhang, Ke He
Summary: This study examines the interaction between off-farm employment decisions between couples and household clean energy consumption in rural China, and finds that two-paycheck households are more likely to consume clean energy. The off-farm employment of women is a key factor driving household clean energy consumption to a higher level, with wage-employed wives having a stronger influence on these decisions than self-employed ones.
Article
Thermodynamics
Hanguan Wen, Xiufeng Liu, Ming Yang, Bo Lei, Xu Cheng, Zhe Chen
Summary: Demand-side management is crucial to smart energy systems. This paper proposes a data-driven approach to understand the relationship between energy consumption patterns and household characteristics for better DSM services. The proposed method uses a clustering algorithm to generate optimal customer groups for DSM and a deep learning model for training. The model can predict the possibility of DSM membership for a given household. The results demonstrate the usefulness of weekly energy consumption data and household socio-demographic information for distinguishing consumer groups and the potential for targeted DSM strategies.
Article
Thermodynamics
Xinglan Hou, Xiuping Zhong, Shuaishuai Nie, Yafei Wang, Guigang Tu, Yingrui Ma, Kunyan Liu, Chen Chen
Summary: This study explores the feasibility of utilizing a multi-level horizontal branch well heat recovery system in the Qiabuqia geothermal field. The research systematically investigates the effects of various engineering parameters on production temperature, establishes mathematical models to describe their relationships, and evaluates the economic viability of the system. The findings demonstrate the significant economic feasibility of the multi-level branch well system.
Article
Thermodynamics
Longxin Zhang, Songtao Wang, Site Hu
Summary: This investigation reveals the influence of tip leakage flow on the modern transonic rotor and finds that the increase of tip clearance size leads to a decline in rotor performance. However, an optimal tip clearance size can extend the rotor's stall margin.
Article
Thermodynamics
Kristian Gjoka, Behzad Rismanchi, Robert H. Crawford
Summary: This paper proposes a framework for assessing the performance of 5GDHC systems and demonstrates it through a case study in a university campus in Melbourne, Australia. The results show that 5GDHC systems are a cost-effective and environmentally viable solution in mild climates, and their successful implementation in Australia can create new market opportunities and potential adoption in other countries with similar climatic conditions.
Article
Thermodynamics
Jianwei Li, Guotai Wang, Panpan Yang, Yongshuang Wen, Leian Zhang, Rujun Song, Chengwei Hou
Summary: This study proposes an orientation-adaptive electromagnetic energy harvester by introducing a rotatable bluff body, which allows for self-regulation to cater for changing wind flow direction. Experimental results show that the output power of the energy harvester can be greatly enhanced with increased rotatory inertia of the rotating bluff body, providing a promising solution for harnessing wind-induced vibration energy.