Article
Energy & Fuels
Xiepeng Sun, Xiaolei Zhang, Jiang Lv, Xiaotao Chen, Longhua Hu
Summary: This work studies the characteristics of buoyant turbulent diffusion flames considering different flame intermittent levels and mean flame projection area. Experimental data and models are proposed to describe the behavior of the flame height and flame projection area. The results show that the mean flame height decreases with increasing burner area, and the flame height decreases with lower intermittent levels.
Article
Engineering, Civil
Alexander Snegirev, Georgios Maragkos, Jeri At Thabari, Bart Merci
Summary: A novel approach is proposed to incorporate finite rate reactions in modeling of turbulent diffusion flame. The approach, called SCM, is applied in large eddy simulations of flame combustion and shows promising results in replicating flame behavior under different scenarios.
FIRE SAFETY JOURNAL
(2023)
Article
Thermodynamics
Jiang Lv, Michael A. Delichatsios, Mary Deligiannis, Hongyu Lu, Xin Li, Yuxuan Ma, Xiepeng Sun, Longhua Hu
Summary: This study presents a comprehensive model for horizontal turbulent jet flame geometries under opposing wind conditions, which is lacking in existing literature. The model is particularly relevant for offshore drilling platforms with horizontal flares and opposing wind. Experimental measurements were conducted for horizontal jets discharged from circular nozzles, and a physical model based on dimensional analysis was derived to describe the flame geometries under different wind speeds. The proposed model successfully captures the flame geometry parameters and predicts the trajectories of horizontal jet fires under opposing wind.
PROCEEDINGS OF THE COMBUSTION INSTITUTE
(2023)
Article
Thermodynamics
Bo Li, Huaxian Wan, Long Ding, Jie Ji
Summary: Experimental investigations were conducted to estimate radiative heating downstream of wind-driven buoyant turbulent diffusion flames. A new triangular prism flame model was established to predict radiant heat flux received by downstream objects. Results show that radiative heat flux decreases with increasing flame spacing and intensifies with increasing wind velocity.
PROCEEDINGS OF THE COMBUSTION INSTITUTE
(2021)
Article
Thermodynamics
Jinfei Zhao, Jiahao Liu, Haihang Li, Jian Wang
Summary: Experimental investigation on horizontal buoyancy-controlled jet fires was conducted to study the flame projection length under different ambient air pressures. It was found that the flame projection length increases with an increase in heat release rate and decreases with increasing ambient air pressure. The relationship between flame projection length and atmospheric pressure can be expressed as a power law.
CASE STUDIES IN THERMAL ENGINEERING
(2021)
Article
Energy & Fuels
Taiyu Wang, Zhenguo Wang, Jianguo Tan, Mingbo Sun, Zun Cai, Yao Liu
Summary: This study investigated the combustion characteristics of a highly-turbulent premixed jet flame influenced by a confined space. The results showed that the flame characteristics at different distances were comprehensively investigated, and a critical value for flame extinction was identified. The flame structures were classified into V-shaped flame, converging flame, and fully developed flame. The presence of intense combustion regions related to CH* and OH* reactions was observed in the confined space.
Article
Thermodynamics
Jinfei Zhao, Jiahao Liu, Chao Ding, Xuehui Wang, Jiang Wang
Summary: Ethylene, an important raw material in the petrochemical industry, is widely used in the production of polyethylene and vinyl chloride. In this study, experiments were conducted on inclined ethylene jet fires to investigate their horizontal extension distances. The results showed that the horizontal extension distance of ethylene jet fires increases with the heat release rate but decreases with the inclined angle. Through similarity analysis, a correlation was established between the dimensionless horizontal extension distance (Lph/d) and the flame Froude number (Frf). Additionally, a correlation was derived between the dimensionless horizontal extension distance and the modified flame Froude number Frf*(Frf* = cos theta 3/4. Frf), which can accurately predict the experimental data.
CASE STUDIES IN THERMAL ENGINEERING
(2023)
Article
Engineering, Civil
Qiang Wang, Feng Guo, Adriana Palacios Rosas
Summary: In this study, experimental investigations were conducted to examine the intermittent flame lengths in both reduced and normal pressures. The results showed that the intermittent flame lengths were positively related to the heat release rate and nozzle diameter. Lower ambient pressure led to significantly higher intermittent flame lengths. Furthermore, a model was established to quantify the intermittent flame lengths in the reduced pressure environment.
FIRE SAFETY JOURNAL
(2023)
Article
Energy & Fuels
Kai Xie, He Liu, Yunjing Cui, Gan Cui, Xingqi Qiu, Jianxin Wang
Summary: The safety of a horizontal spray combustion flame and the design of a heating device for a low-pressure area of a plateau have been widely examined. The shape equation and length of a flame's trajectory are the two most important indexes. The study demonstrates that maintaining rated volume air flow results in coinciding flame trajectories under different atmospheric pressures.
Article
Thermodynamics
Jie Ji, Chen Wang, Longxing Yu
Summary: This study investigated the flame height and air entrainment of two adjacent buoyant turbulent jet non-premixed flames with different heat release rates. Results showed that with increasing burner spacing, the flame merging behaviors can be divided into three stages. The study provided innovative methods for calculating flame height and global air entrainment volume, extending the application scope of interaction fires.
PROCEEDINGS OF THE COMBUSTION INSTITUTE
(2021)
Article
Thermodynamics
Jiarui Zhang, Zhixun Xia, Likun Ma, Liya Huang, Yunchao Feng, Dali Yang
Summary: Experimental investigation was conducted on the aluminum particles turbulent jet flame in this study. The results showed that aluminum particles need to be heated within a certain distance to ignite, and the flame structure can be divided into preheating zone, flame zone, and burnout zone. Increasing the oxidizing ability can significantly improve the flame temperature and reduce the lift-off height and visible length of the flame.
Article
Mechanics
You-An Lee, Chao Sun, Sander G. Huisman, Detlef Lohse
Summary: This study experimentally explores the characteristics of solvent exchange process under turbulent conditions and determines the turbulent oversaturation of trans-anethole. Continuous droplet nucleation occurs downstream and radially across the jet due to limited mixing capacity. This work extends the understanding of solvent exchange to turbulent regime, introducing a novel type of flow and broadening the scope of multicomponent, multiphase turbulent jets with phase transition.
JOURNAL OF FLUID MECHANICS
(2022)
Article
Thermodynamics
Hongyu Lu, Michael A. Delichatsios, Xin Li, Shixiang Liu, Jiang Lv, Longhua Hu
Summary: This study investigates the flame geometry of vertically downward facing buoyant turbulent jet fires under the influence of cross flows. Through experiments and modeling, three characteristic length scales representing flame geometry properties have been identified.
PROCEEDINGS OF THE COMBUSTION INSTITUTE
(2021)
Article
Energy & Fuels
Hongyu Lu, Shixiang Liu, Jiang Lv, Xin Li, Michael A. Delichatsios, Longhua Hu
Summary: This work investigates the flame geometrical characteristics of vertical downward turbulent jet fires in still air. The study proposes a new physical model and conducts CFD simulation to show the combustion structure. The research reveals the inner flow field and average mixture fraction of a downward jet fire and validates the CFD result with experimental data. It also discusses the differences between downward, upward, and horizontal jet fires and presents a physical model considering the initial downward momentum, flame buoyancy, and air entrainment.
Article
Thermodynamics
S. K. Thirumalaikumaran, Gautham Vadlamudi, Saptarshi Basu
Summary: This study investigates the interaction between incident vortex and buoyant diffusion flame. The flame response depends on the vortex strength, and different response regimes are identified. The high-velocity scales imposed during vortex interaction make the flow momentum-dominant, resulting in forward extinction and flame lift-off. The estimation of flame shedding height requires consideration of vortex circulation and velocity scale.
COMBUSTION AND FLAME
(2022)
Article
Energy & Fuels
Xu Fang, Xiaolei Zhang, Richard K. K. Yuen, Longhua Hu
Summary: This study provides an experimental investigation and scaling analysis of diffusion flame side sag behavior, finding that the evolution of flame side sag can be clearly distinguished as four phases, with turning points related to crosswind speed, burner size, and heat release rate. The transition of four phases can also be quantified based on characteristic length scales derived from general dimensionless functions correlating experimental results of upstream and downstream flame side sag lengths.
Article
Energy & Fuels
Jiang Lv, Xiaolei Zhang, Shixiang Liu, Hongyu Lu, Yuxuan Ma, Longhua Hu
Summary: This study investigates the flame morphology of horizontal turbulent jets under different sub-atmospheric pressures, showing that the flame horizontal projection length increases with the heat release rate, while the flame vertical height exhibits a non-monotonic behavior. By using non-dimensional formulas and characteristic length scale, the flame characteristics under various sub-atmospheric pressures are described accurately. The developed integral model takes into account air entrainment mechanism, top hat profiles, and strong plume theory, providing a good representation of the flame morphologic characteristics.
Article
Energy & Fuels
Hanyu Xiong, Xiaolei Zhang, Yanli Miao, Longhua Hu
Summary: This study investigates the flame spread behavior and flammability of heterogeneous fuels involving polystyrene and corrugated cardboard. Experimental results show a five-stage combustion process with a new method proposed to estimate the combustion area on internal surface. By calculating the B numbers, it is found that the flammability of the heterogeneous fuels is increased compared to single components.
Article
Engineering, Environmental
Shixiang Liu, Xiaolei Zhang, Xu Fang, Longhua Hu
Summary: This study investigates the combustion behaviors and instability characteristics of dual jet flames under cross wind, utilizing propane fire sources with different nozzle diameters and separation distances. The results show that the rear jet flame has a smaller tilt angle and lower blow-out cross wind velocity compared to the front jet flame, due to the interference from the front jet flame. The combustion of the front jet flame also has a restrictive effect on the rear jet flame.
PROCESS SAFETY AND ENVIRONMENTAL PROTECTION
(2022)
Article
Thermodynamics
Siyao Jia, Longhua Hu, Yuxuan Ma, Xiaolei Zhang, Osamu Fujita
Summary: This study investigates the downward flame spread and extinction over inclined electrical wire under horizontal wind. The results show a non-monotonic trend of flame spread rate with increasing horizontal wind velocity, identifying four different regimes based on heat transfer mechanisms. The flame spread rate of Cu-core wire and NiCr-core wire exhibit different dependencies on inclination angle, showcasing enhanced quenching effect and weakened blow-off effect with increased inclination angle.
COMBUSTION AND FLAME
(2022)
Article
Energy & Fuels
Yuhang Chen, Xiaolei Zhang, Yanli Miao, Longhua Hu
Summary: This paper experimentally studies the thermal characteristic and flame behavior of dual tandem pool fires in cross airflow. The results show that the flames tend to merge more easily in cross airflow with larger heat release rates of the upstream flame. The maximum temperature in the flame region increases with the increasing cross airflow velocity, and the flame height and flame horizontal projection length are also affected by the separation distance.
Article
Thermodynamics
Xiaolei Zhang, Longhua Hu, Xiaochun Zhang, Xiepeng Sun, Guillermo Rein
Summary: This paper investigates the temperature profiles in ceiling jet induced by a finite line-source fire plume impinging upon an unconfined ceiling. The experimental results show that the temperature profile is two-dimensional and decays differently in different directions. A new equation is derived to describe the temperature profile based on the characteristic length scales. This study provides important data and a new equation for understanding the ceiling jet temperature distributions induced by finite line-sources in building fire science.
PROCEEDINGS OF THE COMBUSTION INSTITUTE
(2023)
Article
Thermodynamics
Yanli Miao, Yuhang Chen, Fei Tang, Xiaolei Zhang, Longhua Hu
Summary: An experimental study was conducted to simulate the downhill spread of a line-source fire over an inclined surface. The study investigated the flame geometry and thermal radiation to the surroundings and the inclined surface. The results showed that the flame height decreased and the flame length along the inclined surface increased with an increased inclination angle.
PROCEEDINGS OF THE COMBUSTION INSTITUTE
(2023)
Article
Thermodynamics
Yuhang Chen, Kazui Fukumoto, Xiaolei Zhang, Yujie Lin, Fei Tang, Longhua Hu
Summary: This study experimentally investigates the flame horizontal lengths of elevated and ground pool fires in cross airflows, and compares them. The quantification of this fundamental problem, which considers the air entrainment and combustion structure change due to the ground's Coanda effect at the leeward side, is of practical significance.
PROCEEDINGS OF THE COMBUSTION INSTITUTE
(2023)
Article
Thermodynamics
Xiaolei Zhang, Yong Yang, Xiepeng Sun, Fei Ren, Xiang Fang, Longhua Hu
Summary: This paper investigates the behavior of facade flames ejected from a top-hung window, and establishes models to describe the characteristics of flame ejection, flame height, and flame depth based on the window's dimensions and opening angle. The study provides valuable data and models for assessing the risk and impact of fires involving top-hung windows on urban environments.
PROCEEDINGS OF THE COMBUSTION INSTITUTE
(2023)
Article
Thermodynamics
Xu Fang, Xiaolei Zhang, Longhua Hu
Summary: This study investigated the projected vertical flame height of buoyant turbulent horizontally-oriented rectangular-source jet fires through experiments. The results show that the flame height initially increases and then decreases with the aspect ratio of the burner, as well as with the heat release rate. A critical dimensionless heat release rate was identified for the transition behavior. The findings provide new insights into the transitional behavior of vertical flame height in rectangular-source jet fires. Rating: 7 out of 10.
PROCEEDINGS OF THE COMBUSTION INSTITUTE
(2023)
Article
Thermodynamics
Yuxuan Ma, Longhua Hu, Yajun Huang, Fukai Chu, Xiaolei Zhang, Zhengda Guo, Siyao Jia, Nan Zhu, Yuhang Chen, Yan Gu
Summary: This paper presents an experimental investigation on concurrent flame spread over composites with flame retardants and external radiation factors. The findings indicate that the flame spread rate, flame preheat length, and flame height of composites with flame retardants may be larger than those without, under high external radiation. The theoretical analysis and experimental results support the conclusion that the thermal conductivity of the fuel-gas mixture and the temperature dependency of molecular diffusivity play significant roles in the heat/mass transfer mechanism of flame spread.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2023)
Article
Thermodynamics
Xiang Fang, Xiepeng Sun, Xiaolei Zhang, Fei Ren, Yong Yang, Longhua Hu
Summary: This article presents an experimental and CFD simulation investigation on temperature evolution and flame behavior in a compartment with a ceiling vent under ambient wind. The study reveals two types of fire behavior regimes inside the compartment for small or large vents. With a small vent, the flame is located at the center and extinguishes due to lack of oxygen. With a large vent, there is a flame transition from windward to leeward accompanied by the transition of temperature distribution.
PROCEEDINGS OF THE COMBUSTION INSTITUTE
(2023)
Article
Construction & Building Technology
Xiaotao Chen, Xiepeng Sun, Xiaolei Zhang, Fei Ren
Summary: Corridor-compartment fire is a crucial issue for evacuation and firefighting in underground spaces. However, limited studies have been conducted to quantify the temperature changes inside the compartment and the corridor ceiling flow induced by such fires with different compartment door sizes and corridor widths. In this study, a reduced-scale experimental model was used to measure and analyze the burning rate and temperature distribution. The results show that there is a non-dimensional correlation for the temperature rise inside the compartment under over-ventilated and under-ventilated conditions. The temperatures of the ceiling flow at the corner between the corridor wall and ceiling increase slowly before reaching under-ventilated condition and decrease significantly with increasing corridor width. A non-dimensional model considering the effect of corridor width is proposed to predict the temperature in underground corridors and assess the fire thermal hazard.
TUNNELLING AND UNDERGROUND SPACE TECHNOLOGY
(2023)
Review
Thermodynamics
Yuhang Chen, Jun Fang, Xiaolei Zhang, Yanli Miao, Yujie Lin, Ran Tu, Longhua Hu
Summary: Pool fire is a diffusion combustion process above a horizontal fuel surface with low initial momentum. It has both scientific significance in classical diffusion combustion studies and practical importance in fire safety engineering.
PROGRESS IN ENERGY AND COMBUSTION SCIENCE
(2023)
Article
Thermodynamics
Pengcheng Zhao, Jingang Wang, Liming Sun, Yun Li, Haiting Xia, Wei He
Summary: The production of green hydrogen through water electrolysis is crucial for renewable energy utilization and decarbonization. This research explores the optimal electrode configuration and system design of compactly-assembled industrial electrolyzer. The findings provide valuable insights for industrial application of water electrolysis equipment.
ENERGY CONVERSION AND MANAGEMENT
(2024)
Article
Thermodynamics
V. Baiju, P. Abhishek, S. Harikrishnan
Summary: Thermally driven adsorption desalination systems (ADS) have gained attention as an eco-friendly solution for water scarcity. However, they face challenges related to low water productivity and scalability. To overcome these challenges, integrating ADS with other desalination technologies can create a small-scale hybrid system. This study proposes integrating ADS with a Thermo Electric Dehumidification (TED) unit to enhance its performance.
ENERGY CONVERSION AND MANAGEMENT
(2024)
Article
Thermodynamics
C. X. He, Y. H. Liu, X. Y. Huang, S. B. Wan, Q. Chen, J. Sun, T. S. Zhao
Summary: A decentralized centroid multi-path RC network model is constructed to improve the temperature prediction accuracy compared to traditional RC models. By incorporating multiple heat flow paths and decentralizing thermal capacity, a more accurate prediction is achieved.
ENERGY CONVERSION AND MANAGEMENT
(2024)
Article
Thermodynamics
Chaoying Li, Meng Wang, Nana Li, Di Gu, Chao Yan, Dandan Yuan, Hong Jiang, Baohui Wang, Xirui Wang
Summary: There is an urgent need to shift away from heavy dependence on fossil fuels and embrace renewable energy sources, particularly in the energy-intensive oil refining process. This study presents an innovative concept called the Solar Oil Refinery, which applies solar energy in oil refining. A solar multi-energies-driven hybrid chemical oil refining system that utilizes solar pyrolysis and electrolysis has been developed, significantly improving solar utilization efficiency, cracking rate, and hydrogen yield.
ENERGY CONVERSION AND MANAGEMENT
(2024)
Article
Thermodynamics
Chao Ma, Guanghui Wang, Dingbiao Wang, Xu Peng, Yushen Yang, Xinxin Liu, Chongrui Yang, Jiaheng Chen
Summary: This study proposes a bio-inspired fish-tail wind rotor to improve the wind power efficiency of the traditional Savonius rotor. Through transient simulations and orthogonal experiments, the key factors affecting the performance are identified. A response surface model is constructed to optimize the power coefficient, resulting in an improvement of 9.4% and 6.6% compared to the Savonius rotor.
ENERGY CONVERSION AND MANAGEMENT
(2024)
Article
Thermodynamics
Sina Bahmanziari, Abbas-Ali Zamani
Summary: This paper proposes a new framework for improving electrical energy harvesting from piezoelectric smart tiles through a combination of magnetic plucking, mechanical impact, and mechanical vibration force mechanisms. Experimental results demonstrate a significant increase in energy yield and average energy harvesting time compared to other mechanisms.
ENERGY CONVERSION AND MANAGEMENT
(2024)
Article
Thermodynamics
Nanjiang Dong, Tao Zhang, Rui Wang
Summary: This study establishes a multiobjective mixed-variable configuration optimization model for a comprehensive combined cooling, heating, and power energy system, and proposes an efficient generating operator to optimize this model. The experimental results show that the proposed algorithm performs better than other state-of-the-art algorithms.
ENERGY CONVERSION AND MANAGEMENT
(2024)
Article
Thermodynamics
Ahmed E. Mansy, Eman A. El Desouky, Tarek H. Taha, M. A. Abu-Saied, Hamada El-Gendi, Ranya A. Amer, Zhen-Yu Tian
Summary: This study aims to convert office paper waste into bioethanol through a sustainable pathway. The results show that physiochemical and enzymatic hydrolysis of the waste can yield a high glucose concentration. The optimal conditions were determined using the Box-Behnken design, and a blended membrane was used for ethanol purification.
ENERGY CONVERSION AND MANAGEMENT
(2024)
Article
Thermodynamics
Sven Klute, Marcus Budt, Mathias van Beek, Christian Doetsch
Summary: Heat pumps are crucial for decarbonizing heat supply, and steam generating heat pumps have the potential to decarbonize the industrial sector. This paper presents the current state, technical and economic data, and modeling principles of steam generating heat pumps.
ENERGY CONVERSION AND MANAGEMENT
(2024)
Article
Thermodynamics
Le Zhang, To-Hung Tsui, Yen Wah Tong, Pruk Aggarangsi, Ronghou Liu
Summary: This study investigates the effectiveness of a current-carrying-coil-based magnetic field in promoting anaerobic digestion of chicken manure. The results show that the applied magnetic field increases methane yield, decreases carbon dioxide production, and reduces the concentration of ammonia nitrogen. Microbial community analysis reveals the enrichment of certain methanogenic genera and enhanced metabolic pathways. Pilot-scale experiments confirm the technical effectiveness of the magnetic field assistance in enhancing anaerobic digestion of chicken manure.
ENERGY CONVERSION AND MANAGEMENT
(2024)
Article
Thermodynamics
Bo Chen, Ruiqing Ma, Yang Zhou, Rui Ma, Wentao Jiang, Fan Yang
Summary: This paper presents an advanced energy management strategy for fuel cell hybrid electric heavy-duty vehicles, focusing on speed planning and energy allocation. By utilizing predictive co-optimization control, this strategy ensures safe inter-vehicle distance and minimizes energy demand. Simulation results demonstrate the effectiveness of the proposed method in reducing fuel cell degradation cost and overall operation cost.
ENERGY CONVERSION AND MANAGEMENT
(2024)
Article
Thermodynamics
Fabio Fatigati, Roberto Cipollone
Summary: Organic Rankine Cycle-based microcogeneration systems that use solar sources to generate electricity and hot water can help reduce CO2 emissions in residential energy-intensive sectors. The adoption of a recuperative heat exchanger in these systems improves efficiency, reduces thermal power requirements, and saves on electricity costs.
ENERGY CONVERSION AND MANAGEMENT
(2024)
Article
Thermodynamics
Lipeng He, Renwen Liu, Xuejin Liu, Xiaotian Zheng, Limin Zhang, Jieqiong Lin
Summary: This research proposes a piezoelectric-electromagnetic hybrid energy harvester (PEHEH) for low-frequency wave motion and self-sensing wave environment monitoring. The PEHEH shows promising power output and the ability to self-power and self-sense the wave environment.
ENERGY CONVERSION AND MANAGEMENT
(2024)
Article
Thermodynamics
Shangling Chu, Yang Liu, Zipeng Xu, Heng Zhang, Haiping Chen, Dan Gao
Summary: This paper studies a distributed energy system integrated with solar and natural gas, analyzes the impact of different parameters on its energy utilization and emissions reduction, and obtains the optimal solution through an optimization algorithm. The results show that compared to traditional separation production systems, this integrated system achieves higher energy utilization and greater reduction in carbon emissions.
ENERGY CONVERSION AND MANAGEMENT
(2024)
Article
Thermodynamics
Qingpu Li, Yaqi Ding, Guangming Chen, Yongmei Xuan, Neng Gao, Nian Li, Xinyue Hao
Summary: This paper proposes and studies a piston-type thermally-driven pump with a structure similar to a linear compressor, aiming to eliminate the high-quality energy consumption of existing pumps and replace mechanical pumps. The coupling mechanism of working fluid flow and element dimension is analyzed based on force analysis, and experimental data analysis is used to determine the pump operation stroke. Theoretical simulation is conducted to analyze the correlation mechanism of the piston assembly. The research shows that the thermally-driven pump can greatly reduce power consumption and has potential for industrial applications.
ENERGY CONVERSION AND MANAGEMENT
(2024)
