Article
Chemistry, Physical
Mustafa Ilbas, Osman Kumuk, Serhat Karyeyen
Summary: This study investigates the distributed regime of hydrogen-enriched kerosene combustion in a gas turbine combustion chamber. By utilizing advanced combustion techniques such as colorless distributed combustion (CDC), the flame temperature can be controlled and the NOX emissions reduced, allowing gas turbines to operate with hydrogen enrichment within wider flammability limits.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2022)
Article
Energy & Fuels
Mengmeng Ren, Yi Kang, Junxue Zhao, Chong Zou, Ruimeng Shi, Bin Li, Dirk Roekaerts
Summary: Oxy-fuel combustion of coal pyrolysis gas can be used as an internal heat source in low-temperature pyrolysis furnaces, resulting in nitrogen-free and versatile pyrolysis gas. Numerical studies reveal the variation of flame temperature and species under ultra-rich conditions, with super-adiabatic flame temperatures occurring at equivalence ratios larger than 3.
Article
Chemistry, Multidisciplinary
Fangyuan Si, Hongming Zhang, Xiangrui Feng, Jiawei Dou, Long Wu, Linglong Li, Lingyun Wang, Lanming Zhao
Summary: The thermal analysis behavior of pulverized coal combustion in different oxygen-rich atmospheres and the effects of heating rate on combustion characteristic were studied. The results showed that the combustion rate of pulverized coal increased and the burnout time decreased under the conditions of an oxygen-enriched atmosphere and high heating rate. The changes in oxygen concentration and heating rate mainly affected the combustion stage of coal samples.
Article
Chemistry, Physical
Neil S. Rodrigues, Colin T. McDonald, Oluwatobi O. Busari, Aman Satija, Robert P. Lucht
Summary: This study investigated the transverse injection of rich, premixed natural gas and air, and natural gas, hydrogen, and air into a high-speed vitiated crossflow under engine-relevant conditions. The research found that flame stabilization near the injector resulted in a significant increase in NOX emissions for both NG-air and NG-H-2-air reacting jets. The flame position and structure were observed to be different for various jet equivalence ratios, indicating different combustion behaviors.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2021)
Article
Energy & Fuels
Xin Wang, Weidong Fan, Jun Chen, Guanyu Feng, Xiang Zhang
Summary: This paper investigates the application of ammonia/coal co-firing in a wall-temperature controlled staged combustion furnace for low carbon and low NOx emissions. The study examines the effects of burnout air addition positions and combustion environmental temperatures on emissions, as well as the release characteristics of co-firing products. Experimental results and chemical kinetic calculations provide insights into the release patterns and mechanisms, presenting a promising solution for reducing CO2 and NOx emissions from coal-fired power plants.
Article
Thermodynamics
Zhenbao Li, Fengshuang Wang, Yongqiao Wei, Rui Liang, Wei Gao, Xiaofeng Zhang
Summary: Coal spontaneous combustion is a worldwide hazard that causes energy resource waste, worker health risk, and atmospheric environmental pollution. This study proposes a novel method to assess the degree of coal spontaneous combustion and provides a theoretical basis for predicting such accidents.
Article
Energy & Fuels
Ming Qiao, Ting Ren, Jon Roberts, Hongwei Liu, Xiaohan Yang, Lihai Tan, Jianming Wu
Summary: Computational fluid dynamics (CFD) is an effective method for solving engineering problems related to spontaneous combustion and abnormal gas emissions. This study used field data to conduct extensive CFD modeling and analysis, investigating the impact of ventilation design and operational measures on managing spontaneous combustion and gas exceedance. Real-time gas monitoring data was used to validate the models. The results showed the importance of goaf seal tightness, inertization parameter optimization, injection flow rate, and the installation of curtains and brattices in preventing heating and reducing methane exceedance.
Article
Energy & Fuels
Tawanda Matamba, Stefan Iglauer, Alireza Keshavarz
Summary: This review paper explores the research progress in the formation of hydrogen rich gas from innovative coal gasification parameters, including the effects of pressure, temperature, catalyst, coal type, and the advantages of coal and biomass co-gasification. The study found that co-gasification and elevated temperatures, pressures, and steam-carbon ratios positively influence hydrogen gas yields, while the presence of different catalysts and sorbents enhances hydrogen concentration in the gaseous products.
JOURNAL OF THE ENERGY INSTITUTE
(2022)
Article
Chemistry, Physical
Alejandro Restrepo, Mateo Viana, Andres Colorado, Andres A. Amell
Summary: The present paper experimentally analyzes the morphology of non-premixed diffusion reactions of hydrogen enriched natural gas (NG). By varying the H2 content from 0 to 100 vol.-% and pre-heating temperatures, the visible flame height is observed to decrease with increasing H2 content in NG at any preheating temperature. The effects of air pre-heating on the visible flame height are influenced by the H2 content in NG.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2023)
Article
Energy & Fuels
Chunjing Liu, Xiude Hu, Gang Chen, Jianyi Lu
Summary: In this study, a diffusion-flamelet-based Hencken burner was used to conduct MILD-OCC combustion experiments of coal particles under low-oxygen dilution conditions. The effects of fuel-air ratio, secondary air, and particle size of pulverized coal on temperature and NOx distributions were investigated. The research provides important insights into the understanding of MILD-OCC regime and the generation mechanism of fuel NOx.
JOURNAL OF THE ENERGY INSTITUTE
(2022)
Article
Thermodynamics
Taesong Lee, Kyu Tae Kim
Summary: The experimental investigation focuses on the combustion dynamics of lean-premixed multislit hydrogen-air flames, revealing complex modal dynamics under high-frequency pressure oscillations. The study demonstrates that pressure fluctuations intensify exponentially with increasing flame temperature, showcasing previously unidentified dynamics induced by lean-premixed multislit hydrogen-air flames.
COMBUSTION AND FLAME
(2022)
Article
Thermodynamics
Alireza Rahbari, Sajad Homayoonfar, Esmaeil Valizadeh, Mohammad Reza Aligoodarz, Davood Toghraie
Summary: The major challenge in the development of micro-combustors is flame instabilities, which lead to non-uniform wall temperature distribution and lower combustion efficiency. This research investigates the combustion characteristics and geometrical configurations on flame stability and combustion efficiency, with a detailed chemical reaction mechanism developed and parametric study conducted. Increasing thermal conductivity coefficient, equivalence ratio, and using a micro-combustor with bluff body are identified as effective ways to improve combustion performance.
Article
Energy & Fuels
Wei Liu, Yunliang Qi, Ridong Zhang, Qihang Zhang, Zhi Wang
Summary: This paper investigates the hydrogen production from ammonia-rich combustion under varying pressures, temperatures, and equivalence ratios. The results show that the current ammonia mechanisms are inadequate in predicting the hydrogen production trend. Moreover, the increase in initial temperature is found to enhance the hydrogen production.
Article
Energy & Fuels
Tao Zhu, Chunli Tang, Xing Ning, Limin Wang, Lei Deng, Defu Che
Summary: The NOx formation characteristics of Zhundong coal in a cyclone furnace were experimentally investigated in this study. The key to reducing NOx emissions in the cyclone furnace is to create a strong reducing atmosphere. Lowering the primary air rate and avoiding centralized air supply can effectively reduce NOx formation. The near-wall zone in the cyclone barrel has higher NOx formation due to elevated O-2 concentration.
Article
Energy & Fuels
Zhichao Chen, Zhenhua Yuan, Yufei Wang, Zhengqi Li
Summary: This study aims to optimize the over-fired air (OFA) distribution by evaluating important gas-particle (GP) parameters that influence the pulverized coal (PC) combustion performance. The results show that an OFA ratio of 1:1 achieves the best combustion performance and reduces NOx emissions.