Article
Thermodynamics
Jun Li, Hongcheng Xiao, Qingqing Li, Junrui Shi
Summary: The study aims to analyze heat fluxes in porous micro-combustors and discuss the effects of wall thermal conductivity and porous media properties on flame temperature. Results show that smaller porous micro-combustors have a higher proportion of heat recirculation relative to heat losses, and flame temperature is inversely related to the ratio of total heat losses to total heat recirculation.
Article
Chemistry, Physical
Yunfei Yan, Chenghua Zhang, Gange Wu, Shuai Feng, Zhongqing Yang
Summary: This paper investigates the temperature distribution and exhaust species in a heat-recirculating micro-combustor embedded with porous media. The results indicate that embedding porous media improves temperature uniformity and preheating capacity. SiC material performs better in thermal stability and heat recirculating than Al(2)O(3) and ZrO2. The optimal equivalence ratio for methane/air combustion is in the range of 0.1-0.5, enabling super-enthalpy combustion.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2022)
Review
Computer Science, Interdisciplinary Applications
Mayssaa Jbeili, Junfeng Zhang
Summary: Extensive pore-scale simulations have been conducted to study microscopic flow and heat transfer processes in porous materials. However, the validity and assumptions of the boundary conditions used in these simulations have not been examined or discussed. In this article, various methods for thermal conditions on periodic unit boundaries and solid-fluid interfaces are reviewed and analyzed. The analysis reveals the constraints and assumptions behind these methods and raises concerns about their applications in porous thermal flow simulations. This study is valuable for new researchers in computational heat transfer and can aid in the development of new boundary conditions in heat and fluid flow simulations in periodic structures.
ARCHIVES OF COMPUTATIONAL METHODS IN ENGINEERING
(2022)
Article
Engineering, Chemical
Siqi Cai, Ziyi Su, Pengfu Xie, Qinghua Zeng, Jianlong Wan
Summary: A novel miniature double-layer disc-combustor with porous media and Swiss-roll preheated channel is developed for the first time. The combustion characteristics of 60%CH4-40%H2-air in this combustor are investigated, showing an anomalous blow-off phenomenon in the radial channel. Additionally, the flame diameter slightly decreases with the decreased equivalence ratio due to the thermal expansion effect. Overall, the present double-layer disc-combustor exhibits good thermal performance in a wide operating range.
CHEMICAL ENGINEERING SCIENCE
(2023)
Article
Chemistry, Multidisciplinary
Qingqing Li, Jiansheng Wang, Jun Li, Junrui Shi
Summary: Inserting porous media into the micro-scale combustor space enhances heat recirculation, extending flammability limits and improving flame stability. A pore-scale model (PSM) is developed to consider the detailed structure of the porous media, showing better understanding of combustion characteristics and flame stability limits compared to the volume-averaged model (VAM). The PSM predicts scattered flame zones, larger flame stability range, and other improved parameters compared to VAM, indicating its suitability for simplification in certain configurations of porous micro-combustors.
APPLIED SCIENCES-BASEL
(2021)
Article
Thermodynamics
Xinjian Chen, Junwei Li, Dan Zhao, Muhammad Tahir Rashid, Xinyuan Zhou, Ningfei Wang
Summary: The experimental investigation in this work reveals that foamed porous media significantly enhance heat transfer efficiency in meso-scale burners, showing notable impacts on flame structure and temperature distribution.
Article
Energy & Fuels
Joseph Harper, Eliot Durand, Philip Bowen, Daniel Pugh, Mark Johnson, Andrew Crayford
Summary: This study investigates the impact of different fuels on non-volatile particulate matter (nvPM) and gaseous emissions from aircraft gas turbine engines. The results show that the use of low aromatic Sustainable Aviation Fuel (SAF) can significantly reduce nvPM mass, number, and size.
Article
Energy & Fuels
Guiyun Zhang, Qingzhao Li, Xinxin Liu, Baiquan Lin, Xiaowen Li
Summary: An improved dual-channel porous combustor was designed and compared with a single-channel combustor under different conditions. The study introduced a new effective thermal conductivity model based on the Kelvin decahedron and quantitatively analyzed external and internal heat circulation efficiency. Results show that the pores density of foam ceramics has varying effects on the burner performance, with significant reductions in temperature nonuniformity observed in the improved dual-channel combustor. Additionally, the addition of external heat recirculation in porous media burners greatly minimized the preheat zone inside the porous medium.
Article
Thermodynamics
Philipp Wachter, Philipp Hoedl, Juraj Raic, Wieser Gerald, Christian Gaber, Martin Demuth, Christoph Hochenauer
Summary: This paper presents the first report of experimental investigations into thermochemical recuperation (TCR) in industrial scale, demonstrating its high methane conversion rates, effective temperature control, and increased furnace power input.
APPLIED THERMAL ENGINEERING
(2022)
Article
Thermodynamics
Ningguang Chen, Yunhua Gan, Dunfeng Shi, Yanlai Luo, Zhengwei Jiang
Summary: An experimental study was conducted to investigate the electrospray counterflow combustion of ethanol in a new type combustor using a porous media as the grounding electrode. The electrospray process was visually separated from the combustion system, and four typical spraying modes were identified. The study discussed the characteristics and classification of flame shapes, as well as the impact of fuel mass fraction on flame diameter and temperature.
Article
Energy & Fuels
Binchuan You, Xiao Liu, Rui Yang, Shilin Yan, Yong Mu, Zhihao Zhang, Jialong Yang, Hongtao Zheng, Shuying Li
Summary: In this study, the flame characteristics and extinction modes of blast furnace gas combustion were investigated using gliding arc plasma assistance. The results demonstrate that gliding arc plasma can extend the extinction limits of blast furnace gas at low air volume flow rates, and the oscillations of heat release rate can be used as a predictive indicator for flameout.
Article
Thermodynamics
Atin Kumar, Jerome Vicente, Jean-Vincent Daurelle, Yann Favennec, Benoit Rousseau
Summary: Porous cellular materials have distinct textures and are of interest for engineering applications. Understanding the conduction-radiation behavior in these materials is crucial for design and optimization. Numerical methods using 3D digitized images and computational techniques have been developed to study coupled heat transfers. A parallelized discrete scale numerical approach is proposed to solve heat transfer in large scale complex cellular materials, which significantly reduces computational efforts and provides accurate results.
HEAT AND MASS TRANSFER
(2023)
Article
Astronomy & Astrophysics
D. Herman, B. Hensley, K. J. Andersen, R. Aurlien, R. Banerji, M. Bersanelli, S. Bertocco, M. Brilenkov, M. Carbone, L. P. L. Colombo, H. K. Eriksen, M. K. Foss, U. Fuskeland, S. Galeotta, M. Galloway, S. Gerakakis, E. Gjerlow, M. Iacobellis, M. Ieronymaki, H. T. Ihle, J. B. Jewell, A. Karakci, E. Keihanen, R. Keskitalo, G. Maggio, D. Maino, M. Maris, S. Paradiso, B. Partridge, M. Reinecke, A. -S. Suur-Uski, T. L. Svalheim, D. Tavagnacco, H. Thommesen, I. K. Wehus, A. Zacche
Summary: We used Planck LFI and WMAP polarization data to constrain the polarized anomalous microwave emission (AME) on large angular scales. By modeling synchrotron emission and the sum of AME and thermal dust emission, we were able to minimize assumptions on the frequency dependence of AME using a template-based dust emission model. Our results showed that the level of polarized AME is sensitive to the prior synchrotron spectral index. Combining Planck, WMAP, and other low-frequency experimental data will be crucial in improving these limits further.
ASTRONOMY & ASTROPHYSICS
(2023)
Review
Engineering, Chemical
Asif Khan, Fazle Hadi, Naveed Akram, Muhammad Anser Bashir, Hafiz Muhammad Ali, Muhammad Mansoor Janjua, Abid Hussain, Riffat Asim Pasha, Ajaz Bashir Janjua, Farukh Farukh
Summary: This study reviews the application of nano fluids in micro/micro channel heat sinks to enhance heat transfer in cooling systems. The use of hybrid nano fluids in different systems is critically analyzed, and other related technologies are discussed.
JOURNAL OF THE TAIWAN INSTITUTE OF CHEMICAL ENGINEERS
(2022)
Article
Thermodynamics
Varanyu Thongkhao, Somboon Sukpancharoen, Boonrit Prasartkaew
Summary: Nowadays, the depletion of fossil-based energy and environmental issues have become important concerns for all life on Earth. Utilizing renewable energy through an efficient system provides an opportunity to address both the depletion of fossil fuels and environmental problems. Among renewable energies, biomass is considered one of the most advantageous forms of energy and can be effectively managed through strategies like energy crops. Gasification, a thermal process that converts hydrocarbon feedstocks into gas fuel, offers high potential in this matter. This research focuses on improving the efficiency of gasification reactors using Porous Media Heat Recuperators (PMHR) to enhance the gasification process and reduce the temperature requirement for running internal combustion engines (ICE).
CASE STUDIES IN THERMAL ENGINEERING
(2023)
Article
Energy & Fuels
Laura L. Trinkies, Marlene Crone, Michael Tuerk, Manfred Kraut, Roland Dittmeyer
Summary: In this study, mono- and bimetallic Pd and Pt catalysts were deposited via supercritical fluid reactive deposition (SFRD) on TiO2 coated additively manufactured substrates. The focus of this work was to evaluate the suitability of these catalysts for the direct synthesis of H2O2 in the liquid phase. The results showed that all catalysts exhibited high activity and productivity, with PdPt bimetallic catalysts showing the highest productivity and an increase in Pd loading leading to a decrease in productivity. Comparison with literature data demonstrated the high suitability of the SFRD method for the proposed application, with the added benefits of simplicity and environmental friendliness in catalyst production.
CHEMICAL ENGINEERING AND PROCESSING-PROCESS INTENSIFICATION
(2024)
Article
Energy & Fuels
Xiongbao Hu, Zuguo Shen, Yu Wang
Summary: It is impossible to control the outer wall temperature of the micro-combustor below the maximum allowable temperature of commercial thermoelectric generators simply through increasing the equivalent heat transfer coefficient. Three simple strategies were developed to improve temperature uniformity, yet none of them could ensure full temperature control.
CHEMICAL ENGINEERING AND PROCESSING-PROCESS INTENSIFICATION
(2024)