Article
Green & Sustainable Science & Technology
Dhruv Raj Karana, Rashmi Rekha Sahoo
Summary: By studying the performance of the exhaust heat exchanger, using a system with twisted ribs can produce more net power than a smooth surface system, and has the potential to improve fuel consumption by 0.65%.
JOURNAL OF CLEANER PRODUCTION
(2021)
Article
Instruments & Instrumentation
Fatma Bayata
Summary: Thermoelectric generators that convert exhaust waste heat into electricity in vehicles face the challenge of low conversion efficiency. In this study, doped calcium cobaltites were produced using sol-gel technique to improve their high temperature thermoelectric properties. By decreasing the grain size and reducing the thermal conductivity, the doped samples showed significantly enhanced thermoelectric performance, with a maximum ZT value 2.5 times larger than that of the pure sample. This research presents a potential candidate for heat recovery in automotive exhaust thermoelectric generators.
SMART MATERIALS AND STRUCTURES
(2022)
Article
Energy & Fuels
Hesham Khalil, Takushi Saito, Hamdy Hassan
Summary: This article presents a comparative experimental study of three different cooling systems used with thermoelectric generators mounted on a chimney for waste heat recovery. The results show that liquid cooling systems are a better option compared to the heat pipes' system, especially when considering the required surface area.
INTERNATIONAL JOURNAL OF ENERGY RESEARCH
(2022)
Article
Energy & Fuels
Ding Luo, Ruochen Wang, Yuying Yan, Wei Yu, Weiqi Zhou
Summary: The study introduces a complete transient fluid-thermal-electric multiphysics coupling field numerical model to evaluate the dynamic performance of automotive thermoelectric generator systems. Results indicate that there is a delay in output response with changes in exhaust temperature, and the changes in output voltage and power are often accompanied by changes in exhaust mass flow rate.
Article
Thermodynamics
Bernardo Buonomo, Furio Cascetta, Anna di Pasqua, Oronzio Manca
Summary: This work numerically investigates the effect of metal foam thickness on the performances of external thermoelectric generators (TEGs) in an automotive exhaust gas line. The study evaluates the influence of metal foam on TEG efficiency for different foam thicknesses, porosity, pore densities, and exhaust gas mass flow rates. Results show that the use of metal foams significantly increases the wall temperatures of the channel and improves TEG efficiency for certain foam thickness values. However, an increase in pressure drop is observed, leading to a decrease in net useful power. Optimal configurations with the highest ratio of electric power to pumping power are identified based on mass flow rate, metal foam thickness, porosity, and pore density values.
THERMAL SCIENCE AND ENGINEERING PROGRESS
(2023)
Article
Thermodynamics
Mohammad Ali Abdelkareem, Mohamed S. Mahmoud, Khaled Elsaid, Enas Taha Sayed, Tabbi Wilberforce, Mohammed Al-Murisi, Hussein M. Maghrabie, A. G. Olabi
Summary: This article discusses the unique utilization of nanofluids in thermoelectric generator (TEG) applications, specifically in waste heat recovery. Nanofluids have been shown to significantly improve heat transfer efficiency and enhance TEG performance. However, further research and development are needed to achieve commercialization of TEG systems.
THERMAL SCIENCE AND ENGINEERING PROGRESS
(2022)
Article
Thermodynamics
Jifu He, Kewen Li, Lin Jia, Yuhao Zhu, Hongyang Zhang, Jianshe Linghu
Summary: This paper provides a comprehensive review of thermoelectric generator applications, efficiency, and costs. It discusses the power density and efficiency of thermoelectric generator systems in various fields, compares them to photovoltaic systems, and highlights the limitations of thermoelectric generator technology. The development of more efficient and cost-effective thermoelectric generator technology is seen as promising in addressing global energy and environmental challenges.
APPLIED THERMAL ENGINEERING
(2024)
Article
Thermodynamics
M. H. Zaher, M. Y. Abdelsalam, J. S. Cotton
Summary: An analytical model was developed to optimize the integrated design of annular thermoelectric generators with heat exchangers, proposing a dimensionless design factor to guide maximizing power generation. The study findings suggest that at the optimum design factor, the material volume of A-TEGs could potentially be reduced by 75% with only an 11% reduction in maximum power output.
ENERGY CONVERSION AND MANAGEMENT
(2022)
Article
Thermodynamics
Wenlong Yang, WenChao Zhu, Banghua Du, Han Wang, Lamei Xu, Changjun Xie, Ying Shi
Summary: A new type of concentric tube heat exchanger is designed to improve the power generation efficiency of the annular thermoelectric generator (ATEG) in automobiles by using a silicone polymer-based thermal conductive oil to transfer heat from the exhaust. Numerical simulations are performed to investigate the effects of various parameters on thermoelectric performance and it is found that the new generator has a 15.2% increase in maximum output power compared to a conventional ATEG, accompanied by a 19% decrease in the optimal thermoelectric module area.
Article
Thermodynamics
B. Singh, W. A. N. W. Mohamed, M. N. F. Hamani, K. Z. N. A. Sofiya
Summary: The research demonstrates that using swirl flows can significantly enhance the power output of a thermoelectric generator module in converting waste heat from a low temperature Polymer Electrolyte Membrane fuel cell into electricity. The swirl strength and cooling modes have a nonlinear impact on power enhancement under different fuel cell power and vehicle drive speeds.
Article
Thermodynamics
Jiahui Liu, Wanli Peng, Houcheng Zhang
Summary: A new cogeneration system model composed of an alkali metal thermal electric converter and a two-stage thermoelectric generator is established to efficiently utilize waste heat and significantly improve power generation efficiency. Mathematical expressions and calculations show that the hybrid system outperforms the sole alkali metal thermal electric converter system in previous studies, offering guidance for optimizing performance through operational conditions and design parameters.
APPLIED THERMAL ENGINEERING
(2021)
Article
Chemistry, Analytical
Xiaodong Jia, Shifa Fan, Zhao Zhang, Hongbiao Wang
Summary: A vehicle aerodynamic heat energy recovery system based on thermoelectric generators (TEGs) is proposed, with a mathematical model established to describe the energy conversion law. The influences of flight conditions on the system's energy conversion behavior are investigated, showing that lower flight altitude and higher Mach number improve system performance, while longer leg lengths affect the temperature and heat absorption of TEGs.
Article
Energy & Fuels
Alaa Attar, Mohamed Rady, Abdullah Abuhabaya, Faisal Albatati, Abdelkarim Hegab, Eydhah Almatrafi
Summary: This article presents an experimental analysis and performance evaluation of using thermoelectric generators (TEGs) for waste heat recovery from residential refrigeration systems. The study demonstrates that integrating HE-TEGs desuperheater unit can significantly improve the overall coefficient of performance and provide sufficient output power for driving the fan.
Article
Energy & Fuels
Miroslaw Neska, Miroslaw Mrozek, Marta Zurek-Mortka, Andrzej Majcher
Summary: Thermoelectric generators are commonly used in low-temperature waste heat conversion systems, but their efficiency and power output can be limited. Increasing the quantity of TEGs used can help boost the power output, while the design of the module is crucial for optimizing heat transfer and maximizing electrical power generation.
Article
Physics, Applied
Ruchika Dhawan, Hari Prasad Panthi, Orlando Lazaro, Andres Blanco, Hal Edwards, Mark Lee
Summary: Thermoelectric generators and coolers offer a potential solution for energy autonomy in internet-of-things and biomedical electronics, as well as local cooling for high-performance integrated circuits. Advancing thermoelectric technology requires research on thermoelectric materials and device physics, particularly in determining thermopower and Peltier coefficients at the device level instead of the material level.
APPLIED PHYSICS LETTERS
(2022)
Article
Thermodynamics
Mahsa Taghavi, Swapnil Sharma, Vemuri Balakotaiah
Summary: This study investigates the natural convection effects in the insulation layers of spherical storage tanks and their impact on the tanks' performance. The permeability and Rayleigh number of the insulation material are considered as key factors. The results show that as the Rayleigh number increases, new convective cells emerge and cause the cold boundary to approach the external hot boundary. In the case of large temperature differences, multiple solutions may coexist.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Jinyang Xu, Fangjun Hong, Chaoyang Zhang
Summary: This study introduces a self-induced jet impingement device for enhancing pool boiling performance in high power electronic cooling. Through visualization and parametric investigations, the effects of this device on pool boiling performance are studied, revealing the promotion of additional liquid supply and vapor exhausting. The flow rate of the liquid jet is found to positively impact boiling performance.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Wenchao Ke, Yuan Liu, Fissha Biruke Teshome, Zhi Zeng
Summary: Underwater wet laser welding (UWLW) is a promising and labor-saving repair technique. A thermal multi-phase flow model was developed to study the heat transfer, fluid dynamics, and phase transitions during UWLW. The results show that UWLW creates a water keyhole, making the welding environment similar to in air laser welding.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Xingrong Lian, Lin Tian, Zengyao Li, Xinpeng Zhao
Summary: This study investigates the heat transfer mechanisms in natural fiber-derived porous structures and finds that thermal radiation has a significant impact on the thermal conductivity in low-density regions, while natural convection rarely occurs. Insulation materials derived from micron-sized natural fibers can achieve minimum thermal conductivity at specific densities. Strategies to lower the thermal conductivity include increasing porosity and incorporating nanoscale pores using nanosize fibers.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Yasir A. Malik, Kilian Koebschall, Stephan Bansmer, Cameron Tropea, Jeanette Hussong, Philippe Villedieu
Summary: Ice crystal icing is a significant hazard in aviation, and accurate modeling of sticking efficiency is essential. In this study, icing wind tunnel experiments were conducted to quantify the volumetric liquid water fraction, sticking efficiency, and maximum thickness of ice layers. Two measurement techniques, calorimetry and capacitive measurements, were used to measure the liquid water content and distribution in the ice layers. The experiments showed that increasing wet bulb temperatures and substrate heat flux significantly increased sticking efficiency and maximum ice layer thickness.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Jinqi Hu, Tongtong Geng, Kun Wang, Yuanhong Fan, Chunhua Min, Hsien Chin Su
Summary: This study experimentally examined the heat dissipation of vibrating fans and demonstrated its inherent mechanism through numerical simulation. The results showed that the flow fields induced by the vibrating blades exhibited pulsating features and formed large-scale and small-scale vortical structures, significantly improving heat dissipation. The study also identified the impacts of different blade structures and developed a trapezoidal-folding blade, which effectively reduced the maximum temperature of the heat source and alleviated high-temperature failure crisis.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Dan-Dan Su, Xiao-Bin Li, Hong-Na Zhang, Feng-Chen Li
Summary: The boiling heat transfer of low-boiling-point working fluid is a common heat dissipation technology in electronic equipment cooling. This study analyzed the interfacial boiling behavior of R134a under different conditions and found that factors such as the initial thickness of the liquid film, solid-liquid interaction force, and initial temperature significantly affect the boiling mode and thermal resistance.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Jinyi Wu, Dongke Sun, Wei Chen, Zhenhua Chai
Summary: A unified lattice Boltzmann-phase field scheme is proposed to simulate dendrite growth of binary alloys in the presence of melt convection. The effects of various factors on the growth are investigated numerically, and the model is validated through comparisons and examinations.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Shaokun Ge, Ya Ni, Fubao Zhou, Wangzhaonan Shen, Jia Li, Fengqi Guo, Bobo Shi
Summary: This study investigated the temperature distribution of main cables in a suspension bridge during fire scenarios and proposed a prediction model for the maximum temperature of cables in different lane fires. The results showed that vehicle fires in the emergency lane posed a greater thermal threat to the cables.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Shuang-Ying Wu, Shi-Yao Zhou, Lan Xiao, Jia Luo
Summary: This paper investigates the two-phase flow and heat transfer characteristics of low-velocity jet impacting on a cylindrical surface. The study reveals that the heat transfer regimes are non-phase transition and nucleate boiling with the increase of heat transfer rate. The effects of jet impact height and outlet velocity on local surface temperatures are pronounced at the non-phase transition stage. The growth rates of heat transfer rate and liquid loss rate increase significantly from the non-phase transition to nucleate boiling stage.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Emad Hasani Malekshah, Wlodzimierz Wlodzimierz, Miros law Majkut
Summary: Cavitation has significant practical importance and can be controlled by air injection. This study investigates the natural to ventilated cavitation process around a hydrofoil through numerical and experimental methods. The results show that the location and rate of air injection have a meaningful impact on the characteristics of cavitation.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Feriel Yahiat, Pascale Bouvier, Antoine Beauvillier, Serge Russeil, Christophe Andre, Daniel Bougeard
Summary: This study explores the enhancement of mixing performance in laminar flow equipment by investigating the generation of chaotic advection using wall deformations in annular geometries. The findings demonstrate that the combined geometry can achieve perfect mixing at various Reynolds numbers.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Hui He, Ning Lyu, Caihua Liang, Feng Wang, Xiaosong Zhang
Summary: This study investigates the condensation, frosting, and defrosting processes on superhydrophobic surfaces with millimeter-scale structures. The results reveal that the structures can influence the growth and removal of frost crystals, with the bottom grooves creating a frost-free zone and conical edges promoting higher frost crystal heights. Two effective methods for defrosting are observed: hand-lifting the groove and airfoil retraction contraction on protruding structures. This research provides valuable insights into frost formation and defrosting on millimeter-structured superhydrophobic surfaces, with potential applications in anti-frost engineering.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Thiwanka Arepolage, Christophe Verdy, Thibaut Sylvestre, Aymeric Leray, Sebastien Euphrasie
Summary: This study developed two thermal concentrators, one with a 2D design of uniform thickness and another with a 3D design, using the coordinate transformation technique and metamaterials. By structuring the thermal conductor, the desired local density-heat capacity product and anisotropic thermal conductivities were achieved. The homogenized thermal conductivities were obtained from finite element simulations and cylindrical symmetry consideration. A 3D concentrator was fabricated using 3D metal printing and characterized using a thermal camera. Compared to devices that solely consider anisotropic conductivities, the time evolution characteristics of the metadevice designed with coordinate transformation were closer to those of an ideal concentrator.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Liangyuan Cheng, Qingyang Wang, Jinliang Xu
Summary: In this study, we investigated the supercritical heat transfer of CO2 in a horizontal tube with a diameter of 10.0 mm, covering a wide range of pressures, mass fluxes, and heat fluxes. The study revealed a non-monotonic increase in wall temperatures along the flow direction and observed both positive and negative wall temperature differences between the bottom and top tube. The findings were explained by the thermal conduction in the solid wall interacting with the stratified-wavy flow in the tube.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)