Article
Energy & Fuels
Chengfei Tao, Hao Zhou
Summary: This study experimentally investigated the effects of preheated steam on combustion instabilities and NOx emissions in a lean-premixed model gas turbine combustor. The results showed that preheated steam injection can effectively reduce sound pressure and NOx emissions, but careful consideration should be given to the design of steam injectors and injection heights.
Article
Thermodynamics
Qiaonan Zhao, Feng Liu, Anyao Jiao, Qiguo Yang, Hongtao Xu, Xiaowei Liao
Summary: A prediction model for NOx emissions in heavy-duty gas turbine combustors based on MILD combustion was proposed. The sensitivity analysis of inlet parameters was conducted to determine their impact on the operation of gas turbines. The results identified the optimal combination of parameters and established a novel prediction model for accurately calculating NOx emissions under complex boundary conditions in MILD combustion.
Article
Engineering, Multidisciplinary
Hazem S. Gitar, Yehia A. Eldrainy
Summary: Novel combustion techniques, such as colorless distributed combustion (CDC) or flameless combustion (FC), have been investigated to reduce emissions from gas turbines due to strict regulations on harmful emissions. The study examined the impact of factors like air diameter, confinement size, and excess air ratio on recirculation ratio in flameless combustion. Results showed a significant influence of combustor diameter and air jet diameter on NOx emissions.
ALEXANDRIA ENGINEERING JOURNAL
(2021)
Article
Chemistry, Physical
Jianbing Gao, Guohong Tian, Chaochen Ma, Yuanjian Zhang, Shikai Xing, Phil Jenner
Summary: Lean-burn was adopted as an effective method in this study to reduce NOx emissions from hydrogen combustion in ORP engines. The equivalence ratio has a significant impact on combustion and NOx emission characteristics, with effects varying with engine speeds. High NOx emissions were observed under low engine speed conditions due to hydrogen combustion near stoichiometric ratio.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2021)
Article
Energy & Fuels
Truc Huu Nguyen, Jungkyu Park, Changhun Sin, Seungchai Jung, Shaun Kim
Summary: This study investigated the influence of pressure on NOx formation in a lean-premixed gas turbine combustor, revealing the changes in NO formation pathways under different pressures. Path analysis was conducted to understand the effect of pressure on NOx emissions.
Article
Chemistry, Physical
Zhaoxing Li, Suhui Li
Summary: This paper conducted a kinetics modeling study on the NO(x) emission characteristics of a staged rich-lean combustor cofiring NH3/H-2 mixture, revealing that the equivalence ratio in the rich-burn stage is a key factor influencing NOx emissions. Balancing NO production and unburnt NH3 in the rich-burn stage is crucial for reducing NOx emissions.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2021)
Article
Chemistry, Physical
V. Viswamithra, M. Gurunadhan, S. Menon
Summary: The search for carbon-free fuel alternatives has led to the consideration of ammonia as a potential source for power generation. However, ammonia combustion poses challenges due to reduced flame speed and reactivity. This study evaluates the effectiveness of two strategies, distributed fuel injection and inlet air pre-heating, in widening the stability limits of swirl combustors operating on methane-ammonia mixtures and analyzes their impact on NOx emissions.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2023)
Article
Thermodynamics
Won Joon Song, Dong -Jin Cha
Summary: This study examines the strength of the coupling between the acoustic field and thermal field in a combustor by analyzing the coherence function between dynamic pressure and heat release rate signals. The results reveal decoupling of the two fields during stable combustion and linear interdependence between the signals at the combustor's acoustic eigenfrequencies during unstable combustion. The formation of interdependence precedes the onset of limit cycle oscillation, suggesting its role in combustion instability.
INTERNATIONAL COMMUNICATIONS IN HEAT AND MASS TRANSFER
(2023)
Article
Green & Sustainable Science & Technology
Jianbing Gao, Guohong Tian, Chaochen Ma, Shikai Xing, Liyong Huang
Summary: Opposed rotary piston engines have high power density and can be used as an ideal power source for hybrid vehicles and range extended electric vehicles. Hydrogen applications can demonstrate the advantages of these engines but worsen nitrogen oxides emissions. Lean-burn was adopted in this investigation to achieve low nitrogen oxides emissions, with results showing that engine speed of 3000 r/min had the highest in-cylinder pressure during combustion and significant increase in heat loss rates through cylinder walls with engine speed.
JOURNAL OF CLEANER PRODUCTION
(2021)
Article
Thermodynamics
P. Zhu, Q. Li, X. Feng, H. Liang, J. Suo, Z. Liu
Summary: This paper develops a new combustor for commercial aircraft engines that can effectively reduce emissions, especially NOx, by adjusting the inlet conditions and fuel ratios. Experimental results show that the combustion efficiency can exceed 99% within a certain range of test conditions, and NOx emissions decrease with the change of test conditions.
JOURNAL OF APPLIED FLUID MECHANICS
(2023)
Article
Thermodynamics
F. Pignatelli, S. Derafshzan, D. Sanned, N. Papafilippou, R. Z. Szasz, M. A. Chishty, P. Petersson, X. -S. Bai, R. Gebart, A. Ehn, M. Richter, D. Lorstad, A. . A. . Subash
Summary: This study investigated the impact of CO2 dilution on the combustion of syngas. The findings showed that CO2 dilution affects the flame structures and the emissions of CO and NOx. The operability range of syngas flames shifted towards fuel-richer conditions with increased CO2 dilution. Syngas flames exhibited flame-pocket structures, and the NOx emission decreased while the CO emission increased with increasing CO2 dilution.
COMBUSTION AND FLAME
(2023)
Article
Chemistry, Physical
Zhigang Liu, Yan Xiong, Ningjing Yang, Lele Ren, Yan Liu, Shijie Zhang, Zhedian Zhang, Xiang Xu
Summary: Key issues in hydrogen gas turbine development include achieving low NOx emissions, prevention of flashback, and thermoacoustic instability. Experimental investigation shows that multi-nozzle array combustion exhibits a broader range of stable combustion compared to MILD combustion. It also ensures nozzle safety and prevents flashback at 40% hydrogen content.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2023)
Article
Energy & Fuels
Donato Fontanarosa, Maria Grazia De Giorgi, Giuseppe Ciccarella, Elisa Pescini, Antonio Ficarella
Summary: The study demonstrates that adding urea to water emulsified fuels can reduce nitrogen oxide emissions without significantly affecting combustion performance.
Article
Thermodynamics
Hamidreza Khodayari, Fatholah Ommi, Zoheir Saboohi
Summary: This study investigated the effects of geometrical characteristics variations on pollutant emissions in a laboratory lean premixed combustor through both numerical and experimental methods. An optimization algorithm based on CFD, CRN, and RSM was utilized to optimize combustion chamber geometry for minimized emissions. The results demonstrated the effectiveness of the CFD-CRN hybrid approach in design and optimization of combustion chambers.
THERMAL SCIENCE AND ENGINEERING PROGRESS
(2021)
Article
Energy & Fuels
Xinlei Liu, Hammam Aljabri, Mickael Silva, Abdullah S. AlRamadan, Moez Ben Houidi, Emre Cenker, Hong G. Im
Summary: The combustion of hydrogen in engines produces few harmful emissions, with the exception of nitric oxides (NOx), which can be reduced under lean-burn conditions. This study investigated the feasibility of hydrogen pre-chamber combustion in a heavy-duty diesel engine using CFD modeling. The results showed that the pre-chamber combustion effectively controlled heat release and reduced NOx emissions, but also decreased complete combustion and combustion stability. The engine operating range could be extended by introducing fuel into the pre-chamber and adjusting the pre-chamber throat diameter to control the pressure rise rate.