Article
Thermodynamics
Hasan Kücük
Summary: Channels with small hydraulic diameters improve the overall heat transfer coefficient and compactness of shell and tube heat exchangers. This study experimentally investigated the effects of mini-channels on the heat transfer coefficient and pressure drop performance. The results showed that mini-channels significantly increased the heat transfer coefficient and had a higher pressure drop.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2023)
Article
Chemistry, Physical
Marcin Kruzel, Tadeusz Bohdal, Krzysztof Dutkowski
Summary: The paper discusses experimental studies of media in heat exchange under low volume conditions, focusing on the condensation process of refrigerants in small heat exchangers. A design for a small heat exchanger for cooling and air conditioning systems is proposed, using future-proof, eco-friendly alternatives to CFC refrigerants.
Article
Nuclear Science & Technology
Valiyollah Ghazanfari, Morteza Imani, Mohammad Mahdi Shadman, Younes Amini, Fazel Zahakifar
Summary: In this study, the influence of twisted tubes and Al2O3 nanofluid on the thermal performance of the shell and tube heat exchanger was investigated using computational fluid dynamics (CFD). The results showed that using twisted tubes instead of smooth tubes increased the heat transfer coefficient by about 20% but increased the pressure drop by about 14%. Simultaneously using 20% nanofluid and twisted tubes resulted in an 8% increase in heat transfer coefficient and a 40% reduction in pressure drop compared to the old heat exchangers with various baffles. Therefore, the use of nanofluids and twisted tubes can enhance thermal performance and reduce economic costs.
PROGRESS IN NUCLEAR ENERGY
(2023)
Article
Thermodynamics
Erik Bartuli, Tereza Kudelova, Miroslav Raudensky
Summary: In this work, shell-and-tube type polymeric hollow fibers heat exchangers (PHFHE) with different fiber configurations were studied, and results showed that the overall heat transfer coefficient of the cross-wound PHFHE was 6 times higher than that of the parallel fibers PHFHE.
APPLIED THERMAL ENGINEERING
(2021)
Article
Thermodynamics
Nae-Hyun Kim, Cheol-Hwan Kim, Ho-Seung Han
Summary: This study investigated the air-side heat transfer and pressure drop characteristics of fin-and-tube heat exchangers with oval or round tubes. Results showed that oval tube samples had better thermal performance under dry conditions, but the reverse was true under wet conditions due to poor condensate drainage from the oval tube. The pressure drops of round tube samples were larger, and under wet conditions, they were larger than under dry conditions. Also, an interesting feature was noticed where the highest j factor was obtained at a two-row configuration.
APPLIED THERMAL ENGINEERING
(2021)
Article
Thermodynamics
Kaifeng Yuan, Yuanliang Liu, Yunzhi Ling, Jingsheng Wei, Zhan Liu
Summary: A shell-and-tube heat exchanger utilizing liquid carbon dioxide (LCO2) was designed for cooling high-temperature mines. Analysis of experimental data and comparison of heat transfer models and pressure drop correlations were conducted. The study found that increasing the outside diameter and decreasing the baffle spacing improved heat transfer performance, while the inner diameter and mass flow rate had a greater impact on pressure drop. The findings provide insights for CO2 utilization and technical guidance for LCO2 shell-and-tube heat exchanger design.
INTERNATIONAL JOURNAL OF GREEN ENERGY
(2023)
Article
Thermodynamics
Nianqi Li, Jiri Jaromir Klemes, Bengt Sunden, Qiuwang Wang, Min Zeng
Summary: Heat exchanger network synthesis is an effective tool for heat recovery in chemical and petrochemical industries. This study proposes a method for HENS considering different shell-side flow arrangements in shell-and-tube heat exchangers. The proposed model aims to minimize the total annual cost by trade-offs between different shell-side heat exchangers, utility cost, and pumping cost. Case studies show that the proposed method with different shell-side baffles can reduce heat transfer area and pressure drop.
Article
Thermodynamics
Navid Bozorgan, Ashkan Ghafouri, Ehsanolah Assareh, Sayed Mohammad Safieddin Ardebili
Summary: The present study modifies the structural design of a shell-and-tube heat exchanger by considering parameters such as the overall heat transfer coefficient and total pressure drop. The optimization of five geometric design variables was conducted using the bees algorithm. The results showed an increase in the overall heat transfer coefficient by 22.78%, with a minimal increase in the total pressure drop by 1.8%.
Article
Engineering, Chemical
Carolina Borges de Carvalho, Esdras Penedo de Carvalho, Mauro Antonio da Silva Sa Ravagnani
Summary: This article investigates the impact of different fouling mechanisms on heat transfer and operating costs in heat exchanger networks, and proposes a model to optimize the mass flow rates in the network to minimize the total annual cost.
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
(2022)
Article
Thermodynamics
D. Dhinesh Kumar, A. Valan Arasu
Summary: This study demonstrates that the TiO2-Ag/distilled water nanocompositefluid has the potential to improve the thermal performance of a horizontal shell and tube heat exchanger by enhancing heat transfer efficiency. Although the nanocompositefluid requires higher pumping power, reducing the size of the heat exchanger and minimizing the pumping power penalty can lead to cost reductions for the heat exchanger.
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
(2021)
Article
Thermodynamics
S. A. Marzouk, M. M. Abou Al-Sood, Emad M. S. El-Said, Magda K. El-Fakharany, M. M. Younes
Summary: In this study, unique tube configurations were designed and modeled to investigate the thermal and hydraulic performance of a helical tube heat exchanger. Experimental and numerical results confirm that the new arrangements have a higher overall heat transfer coefficient compared to the uniform tube distribution. The HTHE6 configuration shows the highest enhancement ratio (125-185%) and the HTHE1 configuration has the highest pressure drop values.
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
(2023)
Article
Energy & Fuels
Marcin Kruzel, Tadeusz Bohdal, Krzysztof Dutkowski, Mykola Radchenko
Summary: This paper presents experimental results on heat transfer in a shell and tube heat exchanger during phase changes of the HFE 7000 refrigerant. The use of a mixture of water and phase change material as a coolant enhances heat exchange in the exchanger, leading to increased heat transfer coefficient and heat efficiency.
Article
Thermodynamics
Wannarat Rakpakdee, Suphakorn Tuntarungsri, Mongkol Pornnattawut, Masaaki Motozawa, Mitsuhiro Fukuta, Weerachai Chaiworapuek
Summary: By altering the configuration of the inlet flow channel, the heat transfer and pressure drop of water flow in double vertical coils and a shell heat exchanger were investigated under 28 kHz ultrasound. The position of activated ultrasonic transducers at P1-P9 was examined for its effects. The results showed that modifying the inlet flow configuration from two to four channels enhanced the Nusselt number by 11.6% on the shell side and increased the heat transfer capability by approximately 9% with ultrasonic irradiation.
APPLIED THERMAL ENGINEERING
(2023)
Article
Thermodynamics
Murat Unverdi
Summary: This study investigated the effect of minichannels on the performance of STHEs, finding that optimal thermodynamic and hydrodynamic conditions were reached in the minichannel tube at Re of approximately 5900. The numerical solutions showed acceptable deviations from experimental results, providing valuable guidance for engineering designs and applications.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2022)
Article
Thermodynamics
Heng Chen, Hamdi Ayed, Riadh Marzouki, Faezeh Emami, Ibrahim Mahariq, Fahd Jarad
Summary: The study demonstrates that using a flat tube and dual conic turbulator can enhance the performance of a heat exchanger, resulting in up to 33% higher heat transfers and 30% less exergy loss compared to a plain tube heat exchanger. The heat exchanger with a modified dual turbulator with convergent embellishment was selected as the economic case with the highest thermal performance enhancement factor (TEF) and net profit of unit transferred heat load (eta(p)), showing an increase in eta(p) up to 1.26 times with the application of an enhanced conical turbulator.
CASE STUDIES IN THERMAL ENGINEERING
(2021)
Article
Thermodynamics
Yunxia Ma, Fei Liu, Honggang Pan, Hongjian Zhang, Shuxia Yan, Ailing Zhang
Summary: This paper proposes a dynamically tunable and switchable perfect infrared absorber that exhibits excellent electrical regulation performance and high absorptance. The absorption mechanism is explained using a multiple interference model, and it is proven to be polarization insensitive.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2024)
Article
Thermodynamics
F. J. dos Santos, G. S. M. Martins, M. Strobel, L. Beckedorff, K. V. de Paiva, J. L. G. Oliveira
Summary: This study investigates the effects of inlet conditions and plate's features on the thermal-flow performance of a gasket plate heat exchanger (GPHE) and assesses the impact of a modified tightening distance on its performance. No systematic study on the combined effects of inlet conditions and assembly accuracy on GPHE performance has been conducted before.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2024)
Article
Thermodynamics
Alok K. Ray, Dibakar Rakshit, K. Ravi Kumar, Hal Gurgenci
Summary: The low thermal conductivity of phase change materials limits the heat transfer rate and application of latent heat storage systems. This numerical study examines the impact of two passive heat transfer enhancement techniques on the thermal performance of a latent heat storage system. The results show that the orientation and position of the heat transfer fluid tube have significant effects on the charging duration, while the discharging duration remains unchanged. The combined effect of orientation and eccentricity reduces the charging duration, but increases the discharging duration compared to the concentric domain.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2024)
Article
Thermodynamics
Yalu Han, Yanlong Wang, Chenyang Liu, Xinmin Hu, Yin An, Zhengcai Li, Jiaxun Jiang, Lizhi Du
Summary: This paper investigates the calculation method of thermal conductivity in NAPLs-contaminated soils. By establishing NAPLs-contaminated soil models and using the Lattice Boltzmann Method (LBM) for calculation, an optimized three-dimensional model with high computational accuracy and efficiency is obtained. The study also finds that saturation and Nz parameters have a significant impact on calculation time, while the thermal conductivity of the two-dimensional model is more sensitive to anisotropy. The influence of porosity and NAPLs content on thermal conductivity should be considered during in-situ thermal desorption.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2024)
Article
Thermodynamics
Mostafa Taha, Song Zhao, Aymeric Lamorlette, Jean-Louis Consalvi, Pierre Boivin
Summary: For the first time, large-eddy simulations (LES) of the near-field region of large-scale fire plumes were performed using a pressure-based Lattice Boltzmann method (LBM) with low-Mach number approximation. The simulations showed quantitative agreement with experimental data and were consistent with previously-published numerical studies. The study demonstrated the computational efficiency of the proposed LBM solver in tackling fire-induced flows, suggesting LBMs as a good alternative candidate for modeling fire-related problems.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2024)
Article
Thermodynamics
Weixin Zhang, Yehang Xie, Yuqiang Ding, Zhao Liu, Zhenping Feng
Summary: This study investigated the impact of upstream slot leakage on the endwall film cooling characteristics of turbine blades. Pressure Sensitive Paint (PSP) technology was used to measure the film cooling characteristics, and numerical analysis was conducted to evaluate the aerodynamic performance. It was found that increasing the mass flow ratio of the upstream slot enhanced film cooling, decreased aerodynamic losses, and reduced the strength of passage vortex. However, reducing the distance between the slot and the blade leading edge only enhanced film cooling without affecting the leakage coverage area.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2024)
Article
Thermodynamics
Rui Zhang, Zhen-lei Li, Yan-sheng Zhang, Dong Chen, Guo Yuan
Summary: This study discusses the heat transfer behavior of different jet forms on steel tubes. The results show that the annular jet performs better in terms of cooling intensity and uniformity. The cooling performances of the two jet forms are similar when the steel tube size is small. Therefore, the planar jet can be considered for smaller diameters due to its simplicity, low cost, and convenience in application.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2024)
Article
Thermodynamics
A. R. Khoei, A. M. Orvati Movaffagh, A. Rezaei Sameti
Summary: This paper presents a comprehensive study on the thermo-mechanical characteristics of oxide-coated aluminum nano-powder. It is found that the thermal conductivity of oxide-coated aluminum nano-powder is significantly lower than that of the bulk aluminum, and it is affected by the density and temperature.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2024)
Article
Thermodynamics
Yanjin Wang, Jintao Xiong, Lingyu Chen, Zhihai Lv, Qian Wang
Summary: A solar radiation transfer model for spray cooling double skin facade (SC-DSF) is proposed in this study. The model is validated by experimental results and various influence factors are analyzed. The effectiveness of adjusting droplet coverage rate and size is also evaluated.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2024)
Article
Thermodynamics
Bostjan Zajec, Blaz Mikuz, Anil Kumar Basavaraj, Marko Matkovic, Matej Tekavcic, Martin Draksler, Leon Cizelj, Bostjan Koncar
Summary: We have developed an advanced experimental setup to investigate flow and heat transfer in an annular channel. The setup allows heat transfer measurements and flow visualization using a temperature-controlled inner tube. Measurements can be conducted in both single-phase and two-phase flow regimes. The setup ensures a uniform velocity field in the annular channel using specially designed inlet and outlet headers. The inner copper tube is heated by water and contains turbulators for enhanced heat transfer and thermocouples for temperature measurement. A three-dimensional conjugate heat transfer CFD model has been developed and validated to accurately estimate heat losses in the setup. This study demonstrates the importance of numerical simulations in improving the interpretation of complex experimental results.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2024)
Article
Thermodynamics
Weijie Chen, Ke Wang, Yongqing Wang, Shantung Tu, Zunchao Liu, Huijuan Su
Summary: In this study, a novel gradient porosity transpiration cooling plate structure (GP-TCPS) is proposed to alleviate heat transfer deterioration caused by non-uniform temperature distribution in transpiration cooling plate structure (TCPS). Computational fluid dynamics (CFD) and response surface method (RSM) were used for qualitative and quantitative analysis of the flow and heat transfer of GP-TCPS. The optimized structure of GP-TCPS significantly improves temperature uniformity, injection pressure, and average cooling efficiency compared to traditional TCPS.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2024)
Article
Thermodynamics
R. Essam, A. Elsaid, W. K. Zahra
Summary: This study presents a novel bioheat model for simulating heat transfer in skin tissue. The model offers an improved representation of thermal dynamics in the skin and has been validated using numerical solutions and experimental measurements. The study highlights the importance of incorporating vascular inlet parameters and thermal relaxation effects in the thermal profile, and suggests potential applications in thermal therapy and wound healing.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2024)
Article
Thermodynamics
Dongbo Shi, Tao Xu, Zifeng Chen, Di Zhang, Yonghui Xie
Summary: The cooling structure design of turbine blades is crucial for the safety and reliability of the gas turbine set. This research investigates different arrangement schemes, including dimple/protrusion arrangements, to enhance the cooling performance. The results show that the arrangement scheme with both passes arranged by dimples has the best comprehensive thermal performance.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2024)
Article
Thermodynamics
Emrehan Guersoy, Hayati Kadir Pazarlioglu, Mehmet Guerdal, Engin Gedik, Kamil Arslan
Summary: The thermo-hydraulic performance of Al2O3/H2O nanofluid with different nanoparticle shapes flowing in a sudden expansion tube with variable sudden expansion inclination angles and elliptical dimpled fins with different diameters were numerically investigated. The results showed that the nanoparticle shapes, sudden expansion inclination angles, and elliptical dimpled fin have significant impact on the thermo-hydraulic performance. This study reveals the novelty and importance of these factors in the research.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2024)
Article
Thermodynamics
Rukun Hu, Xinyu Huang, Xinyu Gao, Liu Lu, Xiaohu Yang, Bengt Sund
Summary: This study examines the impact of applying bottom cross-cut on PCM's spatial distribution in a horizontal LHTES unit using numerical simulation. The findings show that bottom cross-cut can improve the heat storage rate and natural convection heat transfer gain.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2024)