Article
Chemistry, Physical
Ethan S. Hecht, Bikram Roy Chowdhury
Summary: The study measured the visible flame length and heat-flux characteristics of cryogenic hydrogen flames released from high-aspect ratio nozzles, finding that the aspect ratio of the release does not significantly affect the flame length or heat flux.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2021)
Article
Chemistry, Physical
Zhirong Wang, Kewei Jiang, Kun Zhao, Pinkun Guo
Summary: This study experimentally investigated the effects of nozzle inclined angle, diameter, and heat release rate on the characteristics of syngas jet flame. A unified empirical model was established to estimate the horizontal extension length of the syngas jet flame for nozzles with different diameters and inclined angles.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2021)
Article
Engineering, Chemical
Zhenhua Tang, Zhirong Wang, Kun Zhao
Summary: This study investigates the burning behavior of inclined jet flames under the influence of a vertical water curtain by conducting a series of experiments. The results show that an increase in fuel flow rates or nozzle diameter leads to a larger flame extension length. With the increase of flame inclination angle, the flame extension length decreases and the influence of nozzle diameter on the flame extension length is attenuated. A mathematical model is proposed to predict the flame extension length of jet flames with different diameters, fuel flows, and inclinations under the influence of a water curtain, and it is validated by previous research data.
JOURNAL OF LOSS PREVENTION IN THE PROCESS INDUSTRIES
(2023)
Article
Energy & Fuels
Zhenhua Tang, Kun Zhao, Zhirong Wang, Jizhe Wang, Yi Pan
Summary: This study focuses on the burning behaviors of horizontal hydrogen jet fires under the action of a water curtain system. The experimental results show that the shape of the hydrogen jet flame expanded on the water curtain is elliptical at different conditions. A new dimensionless heat release rate is proposed to estimate the flame extension length.
Article
Engineering, Environmental
Jiang Lv, Qiang Wang, Fei Tang, Xiepeng Sun
Summary: This study reported on the different angles from which jet fires issue, which are common hazards in pipeline leakage accidents during the gas storage and transportation process. The experiment measured the essential parameters of flame geometrical profiles, including flame projection length, vertical height, and flame trajectory length, to evaluate jet fire risk and design safety distance between process equipment. The results showed that the flame projection length initially increased to a maximum value before decreasing, the vertical height increased monotonously, and the length of flame trajectory decreased and then increased with the increasing inclined angle. The study also quantified the air entrainment coefficients for different inclined jet flames, providing a good reference for determining the flame size of jet flame in inclined conditions.
PROCESS SAFETY AND ENVIRONMENTAL PROTECTION
(2023)
Article
Energy & Fuels
Ruslan Khamedov, Wonsik Song, Francisco E. Hernandez-Perez, Hong G. Im
Summary: Ammonia combustion is a promising energy source with zero CO2 emissions and potential use in hydrogen combustion. The study provides insights into the heat release characteristics of ammonia in MILD combustion through numerical simulations. The findings have important implications for understanding the combustion behavior and reaction mechanisms of ammonia.
Article
Thermodynamics
Qiang Wang, Longhua Hu, Fei Tang, Adriana Palacios, Suk Ho Chung
Summary: The lifted flame behavior of inclined turbulent jets was experimentally investigated by varying the inclination angle of non-premixed fuel jets. The results showed that the lift-off length increases linearly with the increase in initial fuel jet velocity at a fixed inclination angle. A physical model was developed to quantify the lift-off length, taking into account the effect of jet inclination angle.
COMBUSTION AND FLAME
(2023)
Article
Thermodynamics
Qiang Wang, Xuan Liang, Aquan Lu, Ben Wang, Osamu Fujita, Suk Ho Chung, Longhua Hu
Summary: The blowout behavior of inclined nonpremixed turbulent jet flames is investigated by varying the jet inclined angle. Experimental quantification of the blowout limit and numerical simulations are performed to analyze the flow field difference for different inclined angles. Physical modeling and analysis are conducted to understand the effect of inclined angle on blowout behavior. The findings provide new insights into the blowout limit of nonpremixed inclined turbulent jet flames and propose a model to characterize this behavior.
PROCEEDINGS OF THE COMBUSTION INSTITUTE
(2023)
Article
Energy & Fuels
Yeonse Kang, Kee Man Lee, Jeong Park
Summary: Experimental and numerical studies showed that the UCSD reaction mechanism could accurately trace the characteristics of SNG-air premixed flames, and that the flame stability map is dependent on methane mole fractions and global strain rate. Increasing global strain rate gradually tilts the lean and rich extinction boundaries, leading to the formation of a flammable region island and eventually only one flammable condition.
Article
Energy & Fuels
Xuren Zhu, Thibault F. Guiberti, Renfu Li, William L. Roberts
Summary: Ammonia has the potential to be used as a carbon-free fuel for reducing greenhouse gas emissions. In this study, various heat release rate (HRR) markers for ammonia-methane-air flames were proposed and NH and [OH][CH2O] were found to be suitable HRR markers. The findings of this study are significant for the indirect measurement of HRR in ammonia-methane-air flames.
Article
Engineering, Environmental
Liang Gong, Tianyu Mo, Xianwen Zheng, Yifei Han, Haoyu Wang, Xufeng Yang, Yuchun Zhang
Summary: This study investigates the fire hazards caused by coupled flames in oil-hydrogen integrated refueling stations. The experiments demonstrate that there is a critical diameter for hydrogen jet ignition, which is determined by the release pressure and location of the pool flame. The heat release rate of the coupled fire is higher than that of a single pool flame, and a prediction model is proposed for flame length and width. The temperature of the coupled fire reaches its peak at 0.2 oa and varies with nozzle diameter and distance.
PROCESS SAFETY AND ENVIRONMENTAL PROTECTION
(2023)
Article
Energy & Fuels
Changchun Liu, Linyuan Huang, Tiandiao Deng, Hua Jiang, Pengzhi Wu, Bo Liu, Jun Deng, Zhenmin Luo
Summary: This study investigated the influence of different rear bottom wall lengths on jet diffusion flames under cross-wind conditions. The experimental results showed that the bottom wall had a significant effect on flame blow-out limit, shape, length, and tilt angle. Exceeding a certain length, the rear bottom wall caused the flames to lift-off easily, and the flames adhered to the bottom wall due to the Coanda effect. The empirical formula of flame tilt angle was obtained by analogy analysis and exhibited good correlation with experimental data.
Article
Engineering, Civil
Qiang Wang, Jin Yan, Ben Wang, Le Chang, Adriana Palacios
Summary: This study conducted experiments on turbulent diffusion jet flames under different inclined states and analyzed the flame length and temperature distribution. A theoretical model was derived to describe the effect of jet inclined angle on flame length. The experimental results showed that both flame length and temperature decreased with decreasing angle.
FIRE SAFETY JOURNAL
(2022)
Article
Thermodynamics
Ignacio Trueba-Monje, Jeffrey A. Sutton
Summary: High-resolution and high SNR planar Rayleigh scattering thermometry measurements were used to investigate preheat and reaction zone broadening, turbulent transport of high-temperature gases, and the internal flame structure in highly turbulent jet flames. The results showed significant broadening of the preheat and thermal layers, as well as moderate broadening of the reaction layer. The statistics of temperature and scalar dissipation rate indicated a shift towards higher temperatures and increased strain on the primary reaction zone and flame front under higher turbulence levels.
COMBUSTION AND FLAME
(2023)
Article
Energy & Fuels
Tengyu Liu, Jiaqi Nan, Xiaozhen Jiang, Jingxuan Li, Lijun Yang
Summary: This paper theoretically studies the time-averaged heat release rates of two-dimensional laminar premixed flames subjected to axial oncoming flow perturbations. Two-dimensional conical flame and V-shape flame models are proposed based on the G-equation method. The effects of velocity perturbation models and flame aspect ratio on the time-averaged flame heat release rates are investigated.
Article
Thermodynamics
Hai Zhao, Puzhen Gao, Xiaochang Li, Ruifeng Tian, Hongyang Wei, Sichao Tan
Summary: This study numerically investigates the interaction between flow-induced vibration and forced convection heat transfer in a tube bundle. The results show that the impact of flow-induced vibration on heat transfer varies in different flow velocity regions.
APPLIED THERMAL ENGINEERING
(2024)
Article
Thermodynamics
Rohit Chintala, Jon Winkler, Sugirdhalakshmi Ramaraj, Xin Jin
Summary: The current state of fault detection and diagnosis for residential air-conditioning systems is expensive and not suitable for widespread implementation. This paper proposes a cost-effective solution by introducing an automated fault detection algorithm as a screening step before more expensive tests can be conducted. The algorithm uses home thermostats and local weather information to identify thermodynamic parameters and detect high-impact air-conditioning faults.
APPLIED THERMAL ENGINEERING
(2024)
Article
Thermodynamics
A. Azimi, N. Basiri, M. Eslami
Summary: This paper presents a novel optimization algorithm for improving the water-film cooling system of photovoltaic panels, resulting in a significant increase in net energy generation.
APPLIED THERMAL ENGINEERING
(2024)
Article
Thermodynamics
Duc-Thuan Phung, Chin-Hsiang Cheng
Summary: In this study, a novel CFDMD model is used to analyze and investigate the behavior of thermal-lag engines (TLE). The study shows that the CFDMD model effectively captures the thermodynamic behavior of the working gas and the dynamic behavior of the engine mechanism. Additionally, the study explores the temporal evolution of engine speed and the influence of various parameters on shaft power and brake thermal efficiency. The research also reveals the existence of a thermal-lag phenomenon in TLE.
APPLIED THERMAL ENGINEERING
(2024)
Article
Thermodynamics
Haiying Yang, Yinjie Shen, Lin Li, Yichen Pan, Ping Yang
Summary: The purpose of this article is to find a measure to improve the interfacial thermal transfer of graphene/silicon heterojunction. Through molecular dynamics simulation, it is found that surface modification can significantly reduce the thermal resistance, thereby improving the thermal conductivity of the graphene/silicon interface.
APPLIED THERMAL ENGINEERING
(2024)
Article
Thermodynamics
Qiong Wu, Yancheng Wang, Haonan Zhou, Xingye Qiu, Deqing Mei
Summary: This article introduces a visible methanol steam reforming microreactor, which uses an optical crystal as an observation window and measures the reaction temperature in real-time using infrared thermography. The results show that under lower oxygen to carbon ratio conditions, the microreactor has a higher heating rate and a stable gradient in temperature distribution.
APPLIED THERMAL ENGINEERING
(2024)
Review
Thermodynamics
Giulia Manco, Umberto Tesio, Elisa Guelpa, Vittorio Verda
Summary: In the past decade, there has been a growing interest in studying energy systems for the combined management of power vectors. Most of the published works focus on finding the optimal design and operations of Multi Energy Systems (MES). However, for newcomers to this field, understanding how to achieve the desired optimization details while controlling computational expenses can be challenging and time-consuming. This paper presents a novel approach to analyzing the existing literature on MES, with the aim of guiding practical development of MES optimization. Through the discussion of six case studies, the authors provide a mathematical formulation as a reference for building the model and emphasize the impact of different aspects on the problem nature and solver selection. In addition, the paper also discusses the different approaches used in the literature for incorporating thermal networks and storage in the optimization of multi-energy systems.
APPLIED THERMAL ENGINEERING
(2024)
Article
Thermodynamics
Xuepeng Yuan, Caiman Yan, Yunxian Huang, Yong Tang, Shiwei Zhang, Gong Chen
Summary: In this study, a multi-scale microgroove wick (MSMGW) was developed by laser irradiation, which demonstrated superior capillary performance. The surface morphology and performance of the wick were affected by laser scan pitch, laser power, repetition frequency, and scanning speed. The MSMGW showed optimal capillary performance in alumina material and DI water as the working fluid.
APPLIED THERMAL ENGINEERING
(2024)
Article
Thermodynamics
Maofei Mei, Feng Hu, Chong Han
Summary: This paper proposes an effective local search method based on detection of droplet boundaries for understanding the dynamic process of droplet growth during dropwise condensation. The method is validated by comparing with experimental data. The present simulation provides an effective approach to more accurately predict the nucleation site density in future studies.
APPLIED THERMAL ENGINEERING
(2024)
Article
Thermodynamics
Rahul Kumar Sharma, Ashish Kumar, Dibakar Rakshit
Summary: The study explores the use of phase change materials (PCM) as a retrofit with Heating Ventilation and Air-conditioning systems (HVAC) to reduce energy consumption and improve air quality. By incorporating PCM with specific thickness and fin configurations, significant energy savings can be achieved in comparison to standard HVAC systems utilizing R134a. This research provides policymakers with energy-efficient and sustainable solutions for HVAC systems to combat climate change.
APPLIED THERMAL ENGINEERING
(2024)
Article
Thermodynamics
Zhenhua Ren, Xiangjin Meng, Xingang Qi, Hui Jin, Yunan Chen, Bin Chen, Liejin Guo
Summary: This paper investigates the heat transfer mechanism and factors influencing thermal radiation in the process of supercritical water gasification (SCWG) of coal, and proposes a comprehensive numerical model to simulate the process. Experimental validation results show that thermal radiation accounts for a significant proportion of the total heat exchange in the reactor and a large amount of radiant energy exists in the important spectral range of supercritical water. Enhancing radiative heat transfer can effectively increase the temperature of the reaction medium and the gasification rate.
APPLIED THERMAL ENGINEERING
(2024)
Article
Thermodynamics
Mauro Abela, Mauro Mameli, Sauro Filippeschi, Brent S. Taft
Summary: Pulsating Heat Pipes (PHP) are passive two-phase heat transfer devices with a simple structure and high heat transfer capabilities. The actual unpredictability of their dynamic behavior during startup and thermal crisis hinders their large-scale application. An experimental apparatus is designed to investigate these phenomena systematically. The results show that increasing the number of evaporator sections and condenser temperature improves the performance of PHP. The condenser temperature also affects the initial liquid phase distribution and startup time.
APPLIED THERMAL ENGINEERING
(2024)
Article
Thermodynamics
Ke Gan, Ruilian Li, Yi Zheng, Hui Xu, Ying Gao, Jiajie Qian, Ziming Wei, Bin Kong, Hong Zhang
Summary: A 3-dimensional enhanced heat pipe radiator has been developed to improve heat dissipation and temperature uniformity in cooling high-power electronic components. Experimental results show that the radiator has superior heat transfer performance compared to a conventional aluminum fin radiator under different heating powers and wind speed conditions.
APPLIED THERMAL ENGINEERING
(2024)
Article
Thermodynamics
Xinyi Zhang, Shuzhong Wang, Daihui Jiang, Zhiqiang Wu
Summary: This study focuses on recovering waste heat from blast furnace slag using dry centrifugal pelletizing technology. A comprehensive two-dimensional model was developed to analyze heat transfer dynamics and investigate factors influencing heat exchange efficiency. The findings have important implications for optimizing waste heat recovery and ensuring safe operations.
APPLIED THERMAL ENGINEERING
(2024)
Article
Thermodynamics
Xincheng Wu, An Zou, Qiang Zhang, Zhaoguang Wang
Summary: The boosting heat generation rate of high-performance processors is challenging traditional cooling techniques. This study proposes a combined design of active jet intermittency and passive surface modification to enhance heat transfer.
APPLIED THERMAL ENGINEERING
(2024)