Article
Thermodynamics
P. Horak, M. Formanek, T. Fecer, J. Plasek
Summary: This experimental study focuses on the low mass flux of refrigerants R134a, R404A, and R407C in a smooth vertical evaporator tube with an inner diameter of 32 mm. The results indicate that nucleate boiling dominates the heat transfer in the downward-flow refrigerant, and its effectiveness is dependent on the superheated wall of the evaporator tube. The experimentally obtained Nusselt number correlates well with the predicted Nusselt number for mass flux over 10 kg.m(-2).s(-1).
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2021)
Article
Engineering, Multidisciplinary
Ahmad K. Sleiti, Wahib A. Al-Ammari, Mohammed Al-Khawaja
Summary: Experimental study on utilization of ultra-low temperature waste heat for thermal cooling system is rare, and this study aims to fill this gap by evaluating the performance of a new full-scale TMR system, characterizing operation with different refrigerants, and identifying optimal operating conditions. The study shows that the TMR system achieves energy efficiency of 5.92% and COP of 2.36 at ultra-low temperature of 65℃, and higher values of 9.85% and 3.99 at heat source temperature of 85℃ with different refrigerants. These findings are valuable for the development and optimization of refrigeration and power systems utilizing low-temperature waste heat.
ALEXANDRIA ENGINEERING JOURNAL
(2023)
Article
Energy & Fuels
Sara Khaleghizadeh, Mohammad Reza Morad, Saeed Jowkar, Xing Shen
Summary: Electric vehicles have become increasingly popular, leading to a growing interest in thermal management strategies. This study proposes and examines a heat pump air conditioning system for regulating cabin and battery pack temperatures in different operating conditions. The system's performance is improved by the use of environmentally friendly refrigerants and an ejector placed before the compressor. The results show improved coefficient of performance (COP) for both cooling and heating modes, with R600a and R1234ze(E) performing the best in terms of exergy destruction and efficiency.
JOURNAL OF ENERGY STORAGE
(2023)
Article
Engineering, Electrical & Electronic
Luis E. Guillen Montenegro, Hugo N. Villegas Pico
Summary: This study focuses on the impacts of fast-charging processes of all-electric vehicles (EVs) on electric grids. Detailed and reduced-order simulation models are proposed to determine the power requirements for ac heating and fast-charging of EVs. The reduced-order model shows close agreement with real-time simulation and laboratory experimentation.
IEEE TRANSACTIONS ON TRANSPORTATION ELECTRIFICATION
(2023)
Article
Environmental Sciences
Saji Raveendran Padmavathy, Murugan Paradesi Chockalingam, Nithyanandhan Kamaraj, Godwin Glivin, Venkatesh Thangaraj, Bharathiraja Moorthy
Summary: Climate change is causing global temperatures to rise, with the refrigeration system being a major emitter of greenhouse gases due to the high global warming potential of traditional refrigerants like R134a. This study's mathematical simulation shows that low-GWP refrigerant mixtures, such as R1234ze/R134a, could be environmentally friendly alternatives with improved performance compared to traditional refrigerants.
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
(2022)
Article
Construction & Building Technology
Zongjiang Liu, Wei Xu, Zhong Li, Linhua Zhang, Ji Li, Aisong Li, Airong Feng
Summary: This study investigates the heating performance of radiators at low temperature based on laboratory test data and analyzes the deviation between predicted and actual values, confirming the engineering calculation accuracy. Various types of radiators were studied for their performance at low temperature, obtaining an attenuation rate of heat output at different conditions and presenting a correction coefficient table for selection. Using a TRNSYS platform, the heating effect of radiators was compared with floor radiant heating, showing similar results after number correction, proving the reasonableness of the low-temperature radiator correction.
JOURNAL OF BUILDING ENGINEERING
(2021)
Article
Thermodynamics
Xuetao Liu, Yusheng Hu, Qifan Wang, Liang Yao, Minxia Li
Summary: The study focused on feasible system schemes of CO2 to replace R134a for heat pump heating, proposing a transcritical CO2 cycle system that outperforms traditional systems in terms of energy efficiency, environmental impact, and economics, demonstrating strong competitiveness in the future.
Article
Thermodynamics
Shanshan Guo, Ruixin Yang, Weixiang Shen, Yongsheng Liu, Shenggang Guo
Summary: A DC-AC hybrid rapid heating method is proposed to preheat lithium ion batteries at high state of charge, avoiding exceeding their voltage limit. Experimental results demonstrate that this method can effectively preheat the batteries to the appropriate operating temperature within a short period of time.
Article
Thermodynamics
Theofanis Benakopoulos, William Vergo, Michele Tunzi, Robbe Salenbien, Jakub Kolarik, Svend Svendsen
Summary: This study investigates the impact of changing the control of the heating system in a typical office building from continuous high-temperature operation to high-temperature intermittent heating or continuous low-temperature operation on energy and cost savings. The results show that continuous low-temperature operation can achieve significant energy and cost reductions.
Article
Electrochemistry
Howard Richards, Christopher Vagg
Summary: This paper investigates the performance of internal AC heating on batteries of different sizes, finding that larger cells exhibit a more uneven distribution of surface temperature during internal heating compared to smaller cells. This difference has important implications for temperature measurement and battery management when using internal heating.
Article
Chemistry, Physical
Genaro Longoria, Muireann Lynch, John Curtis
Summary: Hydrogen is gaining attention as a fuel for residential heating due to its relatively high energy density, but its production depends on the power system, potentially impacting electricity prices and renewable generation curtailment. Introducing electrolysers may increase emissions from power generation and slightly raise electricity prices, with optimal locations determined by residential heating demand and surplus power supplies at electricity nodes.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2021)
Article
Energy & Fuels
Viktor Shevchenko, Bohdan Pakhaliuk, Janis Zakis, Oleksandr Veligorskyi, Jaroslaw Luszcz, Oleksandr Husev, Oleksandr Lytvyn, Oleksandr Matiushkin
Summary: This study presents an inductive power transfer system for constant current and constant voltage wireless charging of low-voltage light electric vehicle batteries, utilizing a double single-phase three-level T-type inverter and split transmitting coils. Through the application of an optimal control structure, a modified control strategy, and a detection algorithm, efficient system operation was achieved, leading to increased functionality, safety, and usability of the device. By reaching an energy transfer efficiency of 90% at a transmitted power of 110 W, the feasibility for commercialization of the proposed solution was confirmed.
Article
Thermodynamics
Sven Werner
Summary: This paper presents the findings and conclusions from an inventory of network configurations implemented in several early projects concerning low-temperature district heating systems, which were implemented in both existing and new networks. The main feature is the choice between a cold or warm network for heat distribution, and the suitability of each network configuration depends on the temperatures of the available heat sources. Fourteen possible network configurations were identified for low-temperature district heating.
Article
Thermodynamics
Honglin Lv, Xueye Chen
Summary: A new micromixer mixing method based on AC heating effect was designed, which uses internal Joule heat and external heat sources to adjust fluid disturbance and temperature distribution for enhanced mixing efficiency. Structural parameters and voltage amplitude/conductivity were analyzed to optimize micromixer performance, achieving over 90% mixing efficiency.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2021)
Article
Energy & Fuels
Li Wei Yang, Yan Li, Tong Yang, Hua Sheng Wang
Summary: Reducing electricity consumption is important for domestic heating systems using solar-assisted air source heat pumps. The study found that lowering the hot-water-supply temperature can significantly save electricity, with a decrease of up to 19.1%.
Review
Thermodynamics
Yuheng Du, Guohong Tian, Michael Pekris
Summary: In recent years, carbon dioxide cycles have shown high efficiency and compact structure, with various types of expanders being evaluated for their performance in micro-scale applications. Volumetric expanders are found to have certain advantages due to suitable rotational speed and potential leakage reduction, but both internal and external leakages remain a significant challenge that needs urgent attention.
APPLIED THERMAL ENGINEERING
(2022)
Article
Thermodynamics
Simon Emhardt, Guohong Tian, Panpan Song, John Chew, Mingshan Wei
Summary: This research paper presents a CFD analysis of small scale ORC scroll expanders using variable and constant wall thicknesses. The results show that the variable wall thickness design generates lower gas forces but higher pressure gradients compared to the constant wall thickness design.
Review
Thermodynamics
Delika M. Weragoda, Guohong Tian, Arman Burkitbayev, Kin-Hing Lo, Teng Zhang
Summary: Heat pipes are receiving increasing interest in the thermal management of EV and HEV battery packs due to their superconductive capability, robustness, low maintenance, and longevity. However, the lack of understanding about their limitations during rapid heat fluctuations, adverse environmental conditions, performance under multiple heat loads, failure criteria in battery thermal management, and the lack of simple and versatile thermal models are hindering the commercialization of heat pipe-based battery thermal management systems. This comprehensive review aims to address these issues and provide insights for further development of this promising thermal management system.
APPLIED THERMAL ENGINEERING
(2023)
Review
Energy & Fuels
Dingchen Wu, Mingshan Wei, Ran Tian, Siyu Zheng, Jundi He
Summary: This paper summarizes the effects of various working conditions on the cooling process of supercritical carbon dioxide (SCO2) through extensive experiments and numerical simulations. It provides guidelines for the design of effective cooling systems and condensers.
Article
Thermodynamics
Fei Xu, Ling Hao, Lei Chen, Qun Chen, Mingshan Wei, Yong Min
Summary: This paper proposes a new method of improving wind power accommodation by integrating district heating networks flow rate regulation into power dispatch. The results show that wind power accommodation increases with increasing flow rate due to increased thermal inertia. However, the flow rate cannot be too high as the electricity consumption of water pumps becomes the main reason for improving wind power accommodation.
Article
Thermodynamics
Junfeng Huang, Jianbing Gao, Yufeng Wang, Ce Yang, Chaochen Ma, Guohong Tian
Summary: This paper explores the engine performance and emissions of an opposed rotary piston engine with asymmetric fuel injection. The results show that asymmetric fuel injection leads to improved hydrogen penetration distance, reduced emissions, and better overall performance.
Article
Thermodynamics
Yuheng Du, Michael Pekris, Guohong Tian
Summary: The scroll-type expander is a promising candidate for micro-scale transcritical CO2 waste heat recovery power system. The performance of the expander relies heavily on the flank clearance design. This paper presents a transient CFD analysis of transcritical CO2 scroll expander with varying flank clearance sizes, revealing the optimal range of 100 to 150 μm for efficient operation.
APPLIED THERMAL ENGINEERING
(2023)
Article
Energy & Fuels
Panpan Song, Yawei Zhu, Zhongyan An, Mingshan Wei, Xiaoxia Sun, Yangjun Zhang
Summary: This study proposes a solid-state heat pump using the electrocaloric effect (ECE) with high efficiency and fluid-thermal conjugated heat transfer. Numerical simulation is performed to investigate the correlation between different operating parameters and the performance of the heat pump. The study shows that adjusting the operation parameters can further optimize the performance of the heat pump.
Review
Energy & Fuels
Dan Dan, Yihang Zhao, Mingshan Wei, Xuehui Wang
Summary: As the electric vehicle industry grows, efficient thermal management systems are crucial for battery safety, energy utilization, and vehicle lifespan. This paper presents a comprehensive review of various thermal management approaches for electric vehicle air conditioning systems, battery thermal management systems, and motor thermal management systems. The use of phase change heat transfer process is recommended for heat dissipation or direct cooling in each subsystem. The integration of AC systems, battery thermal management systems, and motor thermal management systems is expected to maximize energy utilization efficiency. The paper discusses the challenges and limitations of existing systems and provides potential avenues for future research. It is expected to serve as a valuable reference for future studies.
Article
Thermodynamics
Yihang Zhao, Dan Dan, Siyu Zheng, Mingshan Wei, Yi Xie
Summary: This study proposes a two-stage eco-cooling control strategy to reduce energy consumption of thermal management systems (TMS) in electric vehicles (EV) while improving cabin thermal comfort and extending battery life. The strategy considers multiple factors such as vehicle speed, weather conditions, passenger characteristics, and battery conditions. It optimizes cabin and battery temperature trajectories using a dynamic programming algorithm in the first stage, and achieves the desired temperature using fuzzy PID-based controllers in the second stage. Experimental results show that the proposed strategy significantly improves battery life and reduces energy consumption compared to traditional controllers.
Article
Thermodynamics
Dingchen Wu, Mingshan Wei, Jundi He, Shuisheng He, Ran Tian
Summary: This paper investigates the flow and heat transfer mechanisms of supercritical carbon dioxide in the supercritical CO2 Brayton Cycle coupled with solar energy under cooling conditions using direct numerical simulation. The effects of property variation, buoyancy, and thermal deceleration under different flow conditions are studied. Buoyancy plays a dominant role in upward flow, enhancing heat transfer, while in downward flow, buoyancy leads to flow laminarization and heat transfer deterioration. Heat transfer recovery is purely due to the increase in turbulence components.
APPLIED THERMAL ENGINEERING
(2023)
Article
Thermodynamics
Rui Dai, Ran Tian, Siyu Zheng, Mingshan Wei
Summary: This paper investigates the Rankine Carnot battery (R-CB) system and proposes a finite-time thermodynamic model to consider the irreversible loss of energy transfer and conversion processes. By combining the finite-time thermodynamic model and life-cycle method, a levelized cost of energy storage model is established to evaluate the economic and energy performance. The global optimization and parametric analysis show that increasing the evaporation temperature, reducing the heat storage temperature, reducing the shared heat exchanger temperature difference, and increasing the shared heat transfer area can improve system performance and reduce the levelized cost of storage (LCOS). The combination of finite-time thermodynamics and the life-cycle method provides a realistic approach for evaluating the technical and economic potential of R-CB systems.
APPLIED THERMAL ENGINEERING
(2023)
Article
Thermodynamics
Yuheng Du, Michael Pekris, Guohong Tian
Summary: This study investigates the impact of sealing cavities on the performance of scroll-type expanders in transcritical CO2 waste heat recovery power systems. The results show that sealing cavities can improve machinery performance, reduce leakage, and optimize pressure imbalance issues. Different shapes of sealing cavities have similar effects in enhancing isentropic efficiency and reducing leakage ratio.
Article
Electrochemistry
Arman Burkitbayev, Delika M. Weragoda, Francesco Ciampa, Kin Hing Lo, Guohong Tian
Summary: In this study, a novel vertically-oriented heat-pipe-based hybrid cooling battery thermal management system (BTMS) was proposed to effectively reduce the surface temperature of cylindrical batteries. The system was numerically evaluated and experimentally validated, showing promising thermal performance.
Review
Chemistry, Multidisciplinary
Xuankai Cao, Yan Gao, Yanteng Li, Delika M. Weragoda, Guohong Tian, Wenke Zhang, Zhanchao Zhang, Xudong Zhao, Baoming Chen
Summary: Hydrogen energy is considered the most promising ultimate energy source due to its high combustion value, cleanliness, and lack of pollution. Electrolysis of water to produce hydrogen has advantages of simplicity, high efficiency, environmental safety, and high-purity hydrogen. However, challenges such as high power consumption and limited large-scale application of catalysts hinder its widespread use. This paper focuses on the research status of metal-organic frameworks (MOFs) and their derivatives for electrocatalytic water splitting, analyzing the relationship between catalytic behavior and catalyst activity as well as proposing strategies to improve catalytic activity. Future development perspectives for MOFs in electrocatalytic water decomposition are also presented.
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)
