Article
Energy & Fuels
Harun Yilmaz, Serhat Karyeyen, Ahmet Umit Tepe, Dieter Bruggemann
Summary: The colorless distributed combustion technique reduces pollutants emissions for a fuel/oxidizer mixture. In this study, the characteristics of colorless distributed combustion of hydrogen/air mixtures were numerically investigated in a micro combustor to overcome the difficulties associated with micro combustion and to obtain a more uniform temperature profile. It was found that colorless distributed combustion could be achieved by decreasing the oxygen concentration at different mixture inlet temperatures.
Article
Chemistry, Physical
Qingbo Lu, Yunchao Wang, Yi Zhang, Baowei Fan, Yu Wang, Evans K. Quaye, Jianfeng Pan
Summary: The heterogeneous reaction characteristics of premixed H2/Air mixture in a micro combustor with a platinum (Pt) catalyst coating on the inner wall were numerically investigated. The presence of an inserted baffle improved the transport of bulk species on the catalytic surface, leading to enhanced fuel conversion ratio. A two-dimensional numerical model with a detailed heterogeneous reaction mechanism was developed and validated, showing significant improvement in the heterogeneous reaction rate and fuel conversion ratio in the combustor with an inserted baffle.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2023)
Article
Chemistry, Physical
Abdelbasset Lachraf, Mohamed Si Ameur
Summary: This paper presents a new design of micro combustor with trapezoidal ribs on its inner wall, which shows promising improvements in thermal performance. Numerical simulations demonstrate the favorable effects of the ribs on temperature distribution and flow residence time. The study also compares the performance of this design with a simple backward facing step micro combustor, highlighting the benefits of the trapezoidal ribs. The results provide valuable insights into heat transfer mechanisms and suggest optimal operating conditions for efficiency and reliability.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2023)
Article
Chemistry, Physical
Yaosong Huang, Yanjun Chen
Summary: A novel technique combining numerical simulation and machine learning is proposed to optimize the combustor geometry of micro thermophotovoltaic system, improving combustion conditions and system performance. Numerical simulations are used to investigate the influences of combustor geometric parameters on flame shape and performance, and the artificial neural network is trained to determine the optimization success. The radiation power of the combustor is optimized to 34.51 W using only 197 data samples.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2022)
Article
Thermodynamics
Hui Rong, Dan Zhao, Tao Cai, Sid Becker
Summary: This study proposes a reverse flow single-channel inlet and double-channel outlet (SIDO) microcombustor for analyzing the thermal performance and nitrogen oxide emission characteristics of ammonia/hydrogen-fuelled energy conversion systems. The findings show that the SIDO combustor has improved thermal performance and reduced nitrogen oxide emissions. Increasing the inlet pressure improves exergy efficiency and reducing nitrogen oxide emissions. Increasing the inlet flow velocity enhances the temperature uniformity of the combustor wall. This study confirms the viability of using the SIDO reverse flow structure to enhance thermodynamic performances in microcombustion energy conversion systems.
APPLIED THERMAL ENGINEERING
(2023)
Article
Energy & Fuels
Qingbo Lu, Qiongyao Wang, Baowei Fan, Yi Zhang, Yu Wang, Muhammad Nauman, Jianfeng Pan
Summary: This numerical investigation explores the effects of an inserted blunt body on the heterogeneous reactions in a micro-catalytic combustor. The study shows that the blunt body enhances the chemical reaction rate and hydrogen conversion ratio by increasing the velocity and adsorption-desorption process near the catalytic surface. Additionally, the increase in blockage ratio has a positive impact on the heat transfer characteristics of the combustor.
Article
Engineering, Environmental
Tao Cai, Aikun Tang, Chong Li
Summary: This study reveals the flame dynamics and stability of ammonia/hydrogen co-firing combustion using experimental and numerical techniques. Experimental results confirm five types of micro-flame structures and delineate a flame stability diagram. The study shows that increasing the blending ratio extends the blowoff limit and enhances flame stability.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Chemistry, Physical
Yi Zhang, Qingbo Lu, Baowei Fan, Lin Long, Evans K. Quaye, Jianfeng Pan
Summary: The effects of multiple rectangular bluff bodies on the H2/air combustion characteristics were studied by changing the total width and number of bluff bodies. The combined use of multiple bluff bodies can further expand the blow-out limit of H2/air. The main factors for flame morphology are the effects of high temperature and viscous force on flow velocity.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2023)
Article
Thermodynamics
Jiangjun Ding, Jiaqiang E, Jintao Li, Lei Cai, Bo Luo
Summary: This study focuses on the thermoelectric conversion system based on porous medium micro-combustor, using the high energy density of micro-combustor to replace traditional battery energy and improve the working time of small equipment. The results show that lower flow rates can improve energy conversion efficiency by using semiconductor materials with better thermoelectric performance, while higher flow rates have a significant impact on thermoelectric conversion performance but are limited by the temperature of thermoelectric materials. Optimization methods include improving temperature uniformity, enhancing thermal conductivity, using mixed combustion, and using segmented thermocouple.
ENERGY CONVERSION AND MANAGEMENT
(2023)
Article
Thermodynamics
E. Jiaqiang, Tian Meng, Jingwei Chen, Weiwei Wu, Xiaohuan Zhao, Bin Zhang, Qingguo Peng
Summary: The study focused on enhancing the non-premixed combustion performance of hydrogen/air in micro combustors, revealing the influence of combustor diameter and inlet velocity on stable combustion. An enhanced combustion method was proposed, showing that reducing hydrogen inlet velocity can significantly improve combustion stability.
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
Chemistry, Physical
Jianfeng Pan, Xiaojie Wang, Qingbo Lu, Linlin Chen, Yu Wang, Evans K. Quaye
Summary: The setting of a convex platform can significantly increase the maximum velocity while reducing the outlet velocity; increasing the height of the convex platform will increase turbulent kinetic energy, but has little effect on combustion intensity; increasing the inlet velocity can raise the axial temperature but decrease fuel conversion rate.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2021)
Article
Chemistry, Physical
Ziqiang He, Yunfei Yan, Ruiming Fang, Zhiliang Ou, Zhonghui Zhang, Zhongqing Yang, Zhien Zhang
Summary: The newly designed MCSB, with a central and bilateral slotted blunt body, shows significant improvement in combustion performance by effectively preventing flame tip opening and exhibiting higher combustion efficiency and blown-off limit. The blown-off limit of MCSB can reach up to 756 cm(3)/s at a flow rate ratio of 0.2 and a bluff body angle of 90 degrees, which is 61.5% higher than that of conventional combustors.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2021)
Article
Energy & Fuels
Qingguo Peng, Jia Wei, Wenming Yang, E. Jiaqiang
Summary: The combustion characteristics and thermal performance of premixed H-2/C3H8/air in a micro planar combustor with a block insert were experimentally and numerically tested. The effects of hydrogen blended fraction, equivalence ratio, flow rate, and block width on flame stability and heat transfer were discussed and analyzed. The results showed that adding hydrogen improved combustion stability in the micro combustor, and the lowest hydrogen blending mole fraction for a steady flame of the premixed H-2/C3H8/air was obtained through experimental study.
Article
Thermodynamics
Linhong Li, Guangyao Yang, Aiwu Fan
Summary: The study verified that a symmetrical configuration of micro-combustor can improve combustion efficiency and radiation efficiency, allowing it to operate at higher average velocities. Furthermore, as the average velocity increases, combustion efficiency decreases monotonically while radiation efficiency and radiant energy output increase first and then decrease.
Article
Energy & Fuels
Harun Yilmaz, Omer Cam, Ilker Yilmaz
Article
Thermodynamics
Harun Yilmaz, Omer Cam, Ilker Yilmaz
Summary: The study looked at the combustion and emission characteristics of H-2/CO/CH4/CO2 blends, investigated stable operating ranges of different mixtures, and found that the addition of CH4 improves rich flammability limits and emissions. Under externally modified acoustic conditions, flame behavior slightly altered but pollutant emissions improved in a more environmentally friendly manner.
COMBUSTION SCIENCE AND TECHNOLOGY
(2021)
Article
Energy & Fuels
Harun Yilmaz, Omer Cam, Ilker Yilmaz
Article
Thermodynamics
Harun Yilmaz, Ilker Yilmaz
Summary: This study investigated combustion and emission characteristics of different gas mixtures in a laboratory-scale combustor, as well as the flame response to acoustic perturbations. Results showed significant differences in NO emissions between gas mixtures, and the onset of flame instability was found to be independent of gas composition. Additionally, pressure and heat release rate oscillations weakened as hydrogen content in the gas mixture increased.
Article
Energy & Fuels
Bugrahan Alabas, Guven Tunc, Murat Tastan, Ilker Yilmaz
Summary: This study investigates the instability changes of oxygen-enriched fuel mixtures under acoustic enforcement in a premixed and swirl supported system. Experimental results show that increasing oxygen enrichment up to 24% ratio can increase stability by enhancing the laminar flame speed, but stability decreases at 26% oxygen content in the oxidizer. Additionally, the addition of oxygen increases NOx emissions due to higher adiabatic temperature, while reducing CO emissions.
Article
Chemistry, Physical
Ilker Sivri, Harun Yilmaz, Omer Cam, Ilker Yilmaz
Summary: This study experimentally investigated the effects of fuel composition, swirl number, and hydrogen addition on combustion and emission characteristics of various biogas mixtures, and concluded that hydrogen addition can lead to changes in temperature distribution and emission characteristics of biogas mixtures.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2022)
Article
Chemistry, Physical
Bugrahan Alabas, Guven Tunc, Murat Tastan, Ilker Yilmaz
Summary: This study investigated the effects of hydrogen content and oxygen enrichment on synthetic gas mixtures. The results showed that increasing hydrogen content decreased the oxygen enrichment limit and caused flame instabilities. Furthermore, oxygen enrichment resulted in reduced CO emissions but increased NOx values for all synthetic gas mixtures.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2022)
Article
Energy & Fuels
Ilker Yilmaz, Yakup Cam, Bugrahan Alabas
Summary: The study found that the combustion stability of biogas mixtures increases with nitrogen ratio up to 30% N2, but decreases when exceeded. Nitrogen dilution helps the flame resist against 110 Hz frequency while increasing CO emissions and reducing NOx pollutants up to 20% N2, but NOx emissions increase after 20% N2.
Article
Energy & Fuels
Bugrahan Alabas, Guven Tunc, Murat Tastan, Ilker Yilmaz
Summary: The effect of enriching a low calorific biogas mixture with hydrogen and oxygen on combustion stability and exhaust emissions in a premixed burner was investigated. It was found that adding hydrogen to the biogas increased the heating value of the mixture and reduced instabilities. The mixture containing 20% H2 burned at the 23% O2 ratio showed the lowest emission and resistance to acoustic perturbation.
Article
Energy & Fuels
Ilker Yilmaz, Bugrahan Alabas, Murat Tastan, Guven Tunc
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.
