Heat Transfer最新文献

{"title":"Modeling Thin-Layer Drying Kinetics of Justicia adhatoda Leaves Using Different Drying Techniques and Its Quality Evaluation","authors":"Sudarshan Ramanathan,&nbsp;P. Dinesh Kumar,&nbsp;Sumit Sudhir Pathak","doi":"10.1002/htj.70073","DOIUrl":"https://doi.org/10.1002/htj.70073","url":null,"abstract":"<div>\u0000 \u0000 <p>Drying of medicinal herbs like <i>Justicia adhatoda</i> is essential to maintaining their bioactive constituents, but conventional methods tend to degrade quality by subjecting them to excessive heat for long periods. To overcome this, the current research compares and assesses the drying kinetics, phytochemical retention, and optical quality of <i>J. adhatoda</i> leaves under cabinet tray drying (CTD) and microwave drying (MD). Since the plant has pharmacological importance, the research seeks to select a drying process that guarantees efficiency and quality retention. Experimental drying was carried out at different temperatures (45°C–75°C) for CTD and microwave powers (200–700 W) for MD. Among the 11 thin-layer models, Page's model proved to be the most reliable in predicting drying behavior for both processes (<i>R</i>² = 0.999) for CTD and (<i>R</i>² = 0.996) for MD. MD under 360 W took the shortest time, whereas 200 W maintained the maximum total flavonoids and tannin contents. Antioxidant activity was maximum at 360 W, indicating maximum retention of functional constituents under optimal microwave power. Microwave-dried samples exhibited better color preservation, demonstrating its capability to retain sensory as well as commercial acceptability. The results of this study have important consequences for the herbal processing industries, allowing scalable, high-quality drying schemes to be developed that protect the therapeutic and cosmetic worth of medicinal crops.</p>\u0000 </div>","PeriodicalId":44939,"journal":{"name":"Heat Transfer","volume":"54 7","pages":"4260-4278"},"PeriodicalIF":2.6,"publicationDate":"2025-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145237142","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impact of Plasma-Activated Water Pretreatment and Hot-Air Drying on Bioactive Compounds, Drying Kinetics, Structural Characteristics, and Functional Properties of Debittered Sweet Orange Peel Powder","authors":"Venkatraman Bansode,&nbsp;S. Ganga Kishore,&nbsp;Rahul Rajkumar,&nbsp;Madhuresh Dwivedi,&nbsp;Rama Chandra Pradhan,&nbsp;Robbarts Nongmaithem,&nbsp;G. Jeevarathinam,&nbsp;Deepa Jaganathan","doi":"10.1002/htj.70062","DOIUrl":"https://doi.org/10.1002/htj.70062","url":null,"abstract":"<div>\u0000 \u0000 <p>Sweet orange peel, a major by-product of juice processing, is recognized as a bioactive-rich material abundant in phenolic compounds, offering substantial potential for valorization and sustainable by-product utilization. This study investigates the effect of plasma-activated water (PAW) pretreatment combined with hot-air tray drying on the drying behavior and quality attributes of debittered sweet orange peel. Drying was conducted under varying temperatures (50°C, 60°C, and 70°C) and air velocities (0.3, 0.6, and 0.9 m/s). The results demonstrated a significant reduction in drying time, from 465 to 225 min in treated samples (PAW-pretreated tray-dried) and from 420 to 165 min in control samples (non-pretreated tray-dried), as the temperature increased from 50°C to 70°C. Among the tested mathematical models, the logarithmic model provided the best fit for describing drying kinetics. The optimal drying condition, identified as 60°C and 0.9 m/s air velocity, resulted in sweet orange peel powder with enhanced phenolic content and improved functional, structural, and physical attributes. Treated samples exhibited significantly reduced oil absorption capacity, water absorption capacity, and swelling capacity compared with control samples. Scanning electron microscopy analysis revealed compact, dense structures in control samples, while treated samples displayed porous structures with visible spacing between particles. Relative crystallinity increased from 18.09% in control samples to 21.45% in treated samples, indicating structural transformation. Fourier-transform infrared spectroscopy confirmed the presence of key functional groups, such as hydroxyl and carbonyl, associated with the peel's bioactive compounds. These findings highlight the synergistic effect of PAW pretreatment and hot-air drying in enhancing the quality and properties of sweet orange peel powder, offering an effective strategy for the valorization of citrus fruit waste.</p>\u0000 </div>","PeriodicalId":44939,"journal":{"name":"Heat Transfer","volume":"54 7","pages":"4239-4259"},"PeriodicalIF":2.6,"publicationDate":"2025-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145237393","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Drying Kinetics, Characteristics, and Quality Assessment of Hot-Air Dried Semi-Dried Biser Stage Dates Using Computer Vision","authors":"Abdullahi Idris Muhammad,&nbsp;Mai Al-Dairi,&nbsp;Maha Al-Khalili,&nbsp;Nasser Al-Habsi,&nbsp;Pankaj B. Pathare","doi":"10.1002/htj.70042","DOIUrl":"https://doi.org/10.1002/htj.70042","url":null,"abstract":"<div>\u0000 \u0000 <p>Drying dates to a semi-dried, soft, preferred by most consumers, remains a challenge for small-scale processors due to limited control, longer drying time, quality degradation, and other inefficiencies of traditional methods such as open-sun drying. This study investigated the mechanical hot-air drying kinetics and characteristics and evaluated quality changes after drying of <i>Biser</i> dates from 57% to 30% moisture content (wet basis) at various temperatures using a state-of-the-art computer vision system (CVS). This study findings revealed that drying time decreased with increasing temperature, with the shortest drying time observed at 70°C (14.5 h) and the drying occurred predominantly in the falling rate period. Additionally, among the three thin-layer drying models investigated in this study, Page model stands out as the best fitting model to describe the mechanical hot-air drying behavior of <i>Biser</i> dates, having an uppermost coefficient of determinations (<i>R</i>²) of (0.9899–0.9984) and least standard error (SE). The effective moisture diffusivity (<i>D</i>_<i>eff</i>) followed second Fick's diffusivity model and fall between a range from 3.50 × 10⁻¹⁰ to 5.84 × 10⁻¹⁰ m²/s across the temperatures studied (50°C, 60°C, and 70°C). Higher temperatures led to greater shrinkage but helped prevent surface cracking. Notably, CVS measurements showed significant differences (<i>p</i> &lt; 0.05) in shrinkage across samples, with 60°C and 70°C yielding higher volumetric shrinkage. Rehydration capacity was highest at 60°C (45.47%), followed by 70°C (34.21%) and 50°C (20.99%). Overall, drying at 70°C provided the most efficient balance between drying time and product quality, making it the optimal condition for small-scale processors already transitioning to mechanical hot-air drying. It also reduced drying period, minimized quality losses, improved operational consistency, and product standard in the shift away from traditional methods. Future research should focus on sensory evaluation to assess consumer acceptance of semi-dried <i>Biser</i> dates processed under these conditions.</p></div>","PeriodicalId":44939,"journal":{"name":"Heat Transfer","volume":"54 7","pages":"4223-4238"},"PeriodicalIF":2.6,"publicationDate":"2025-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145237187","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental Evaluation of Hot Air-Assisted Continuous Microwave Drying of Oyster Mushroom (Pleurotus ostreatus)","authors":"P. V. Alfiya,&nbsp;G. K. Rajesh,&nbsp;S. Murali,&nbsp;D.S. Aniesrani Delfiya,&nbsp;Manoj P. Samuel,&nbsp;M. V. Prince,&nbsp;K. P. Sudheer,&nbsp;Lilia Baby","doi":"10.1002/htj.70029","DOIUrl":"https://doi.org/10.1002/htj.70029","url":null,"abstract":"<div>\u0000 \u0000 <p>This study evaluated the efficiency of hot air−assisted continuous microwave (HACM) drying for oyster mushrooms (<i>Pleurotus ostreatus</i>), focusing on drying kinetics, quality attributes, and economic feasibility. Response surface methodology was used to optimize drying parameters viz., microwave power (600–1000 W), air temperature (40°C–60°C), and airflow rate (0.5–1.5 m/s), to minimize drying time and water activity while maximizing rehydration ratio. Optimal conditions obtained were air temperature, microwave power, and air flow rate of 55.05°C, 1000 W, 0.81 m/s, respectively, with a drying time of 5 h, water activity of 0.532, and rehydration ratio of 2.49. The dried mushrooms showed 29.63% shrinkage, a total color change of 28.51, pore sizes of 2.06–15.70 µm, and a sensory acceptability score of 8.1. Proximate analysis indicated enhanced protein (33.21%) and carbohydrate (47.34%) contents. The HACM system achieved energy efficiency and specific energy consumption of 23.12% and 2.71 kWh/kg, respectively. The benefit-cost ratio of 1.55 and a payback period of 2.56 years confirmed the economic viability of the system and its potential for scalable and high-quality mushroom preservation.</p></div>","PeriodicalId":44939,"journal":{"name":"Heat Transfer","volume":"54 7","pages":"4207-4222"},"PeriodicalIF":2.6,"publicationDate":"2025-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145237048","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thermal Performance Investigation of Single-Pass Tubular Solar Air Heater for Different Duct Heights","authors":"Disha Dewangan,&nbsp;Jasinta Poonam Ekka,&nbsp;Harish Kumar Ghritlahre","doi":"10.1002/htj.70028","DOIUrl":"https://doi.org/10.1002/htj.70028","url":null,"abstract":"<div>\u0000 \u0000 <p>Solar air heaters play a significant role in addressing global food loss challenges caused by overproduction, underproduction, limited availability, and inefficiencies in distribution and supply chains. These systems are widely utilized for drying applications, industrial heating, and various thermal energy processes. This study focuses on a comparative experimental analysis of single-pass tubular solar air heater (SP-TSAH) and flat plate solar air heater (FP-SAH) designs. It investigates the effect of four different duct heights: 60, 70, 80, and 90 mm, under varying air mass flow rates of 0.004, 0.007, and 0.01 kg/s, aiming to determine the most effective duct height based on thermal efficiency and outlet air temperature. The experiments, conducted between April and May 2024, involved tubular absorbers with a diameter of 38 mm and a pitch of 43 mm. Results revealed that the single-pass tubular solar air heater design achieved the highest outlet temperature of 86.7°C and an average temperature of 73.8°C at a duct height of 60 mm with an airflow rate of 0.004 kg/s. At a higher airflow rate of 0.01 kg/s, the same configuration yielded peak and average thermal efficiencies of 42.6% and 35.8%, respectively. In contrast, the flat plate solar air heaters reached maximum and average efficiencies of 37.2% and 29.6% at the same duct height. While the 90 mm duct height showed a notable efficiency improvement of 59.5% at the lowest airflow rate, the 60 mm configuration consistently offered the best thermal performance across both solar air heater types regarding outlet temperature and energy efficiency.</p>\u0000 </div>","PeriodicalId":44939,"journal":{"name":"Heat Transfer","volume":"54 7","pages":"4776-4792"},"PeriodicalIF":2.6,"publicationDate":"2025-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145237349","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of Temperature Dependent Viscosity in Convective Heat Transfer of Newtonian Fluids Through Vertical Permeable Parallel Plates With Uniform Suction/Injection Considering Internal Heat Generation","authors":"Sumanta Chaudhuri,&nbsp;Rajiva Lochan Mohanty,&nbsp;Paromita Chakraborty,&nbsp;Vijay Kumar Mishra,&nbsp;Mrutyunjaya Das,&nbsp;Bitanjaya Das","doi":"10.1002/htj.70027","DOIUrl":"https://doi.org/10.1002/htj.70027","url":null,"abstract":"<div>\u0000 \u0000 <p>Magnetohydrodynamic convective heat transfer in a Newtonian fluid through vertical, permeable parallel plates with uniform injection/suction is considered. The effects of temperature-dependent viscosity and internal heat generation are included. Walls are considered to be maintained at uniform but different temperatures. The novelty of the work lies in considering temperature-dependent viscosity which results in coupled momentum and energy conservation equations. Further, properly implementing the Least Square Method (LSM) for solving coupled differential equations is demonstrated. LSM generates semi-analytical solutions for velocity and temperature in the Symbolic computation platform of MATLAB. Effects of Reynolds viscosity parameter, cross-flow Reynolds number, Peclet number, heat generation/absorption parameter, buoyancy parameter, Hartmann number and Brinkman number on velocity, temperature, entropy generation and Bejan number are examined in detail. When the temperature coefficient of the viscosity parameter increases from 0.02 to 0.8, (causing a decrease in viscosity) velocity increases from 0.25 to nearly 0.50. The peak temperature attains a value of 1.1 for cross-flow Reynolds number 0.1. Effect of temperature gradient on total entropy generation in marginal as it is less compared to velocity gradient. Bejan number reaches peak value in the region where velocity is more. The results of the present study can be useful for the design of fluid and thermal systems in the filtration process, and chemical engineering.</p>\u0000 </div>","PeriodicalId":44939,"journal":{"name":"Heat Transfer","volume":"54 7","pages":"4761-4775"},"PeriodicalIF":2.6,"publicationDate":"2025-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145237348","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multiobjective Numerical Analysis of Thermal and Fluid Dynamics Performance of a Vertical Helical Earth–Air Heat Exchanger Using the TOPSIS Method","authors":"Andre Luis Razera,&nbsp;Igor Silva Vaz,&nbsp;Roberta Juliana Collet da Fonseca,&nbsp;Michel Kepes Rodrigues,&nbsp;Luiz Alberto Oliveira Rocha,&nbsp;Elizaldo Domingues dos Santos,&nbsp;Liércio André Isoldi","doi":"10.1002/htj.70022","DOIUrl":"https://doi.org/10.1002/htj.70022","url":null,"abstract":"<p>The present work numerically investigates an Earth–Air Heat Exchanger (EAHE) of the vertical helical (VH) type, with regard to the prevailing climate and soil attributes of Rio Grande city, in southern Brazil, through the variation of its pitch between the helicoids (<i>P</i>_h), with constant air flow and soil conditions. The goals are to maximize the Thermal Potential (<i>TP</i>) and minimize the Pressure Drop (<i>PD</i>) of the EAHE-VH, that is, it is a problem involving multiobjectives. The Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) is employed for multiobjective evaluation, and its application is assessed in relation to the results of the Coefficient of Performance (<i>COP</i>) and the Energy Performance Indicator (<i>EPI</i>). The problem is numerically solved using ANSYS FLUENT package, through verified and validated computational models of thermal and fluid dynamics approaches. Among the evaluated <i>P</i>_h values, the configuration with <i>P</i>_h = 100 mm delivered the best <i>TP</i> for both cooling and heating, achieving gains of up to 20% compared with the least favorable geometry (<i>P</i>_h = 400 mm), thereby highlighting the significant influence of the helical pitch on system performance. Conversely, the configuration with <i>P</i>_h = 400 mm demonstrated the best performance in terms of <i>PD</i>, with a reduction of approximately 65.33%. The TOPSIS method effectively identified the optimal geometry with a balanced performance between <i>TP</i> and <i>PD</i>, with <i>P</i>_h = 300 mm being ideal when both are equally prioritized. In contrast to the evaluations based on <i>COP</i> and <i>EPI</i>, the TOPSIS method demonstrated superior comprehensiveness and flexibility, enabling the identification of optimal configurations aligned with distinct operational priorities.</p>","PeriodicalId":44939,"journal":{"name":"Heat Transfer","volume":"54 7","pages":"4689-4707"},"PeriodicalIF":2.6,"publicationDate":"2025-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/htj.70022","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145237309","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Smart Integration of Expandable Graphite in Composite Phase Change Materials for Optimized Electric Vehicle Battery Thermal Management","authors":"Vallapureddy Siva Nagi Reddy,&nbsp;Bandaru Naga Sai,&nbsp;Addagarla Suri Babu,&nbsp;Atcha Avinash,&nbsp;Talla Apparao Rajesh,&nbsp;Aleti Venkata Siva Manohar,&nbsp;Abdul Arif","doi":"10.1002/htj.70026","DOIUrl":"https://doi.org/10.1002/htj.70026","url":null,"abstract":"<div>\u0000 \u0000 <p>Conventional battery thermal management systems in electric vehicles often face critical limitations, such as excessive system weight, low thermal conductivity of phase change materials, poor thermal contact resistance, slow response to transient loads, inadequate flame resistance, and inefficient utilization of latent heat storage. These shortcomings result in uneven heat dissipation, thermal hotspots, and reduced battery lifespan and safety. To overcome these limitations, this study introduces an advanced composite solution incorporating expandable graphite (EG) into paraffin (PA)-based materials. Expandable graphite, recognized for its excellent thermal stability and flame-retardant properties, is strategically blended with paraffin wax to significantly boost both thermal conductivity and fire resistance. As a result, the composite achieves a thermal conductivity of (27.10 W/mK) over 100 times greater than that of pure paraffin (0.24 W/mK) and enhances mechanical strength with tensile and compressive limits reaching 9.0 MPa and 39.4 MPa, respectively. Additionally, the system effectively reduces battery surface temperatures to below 42°C during high-load operation, compared to over 52°C in conventional setups. This study uniquely combines the integration of expandable graphite into paraffin with optimization of its distribution using a novel biased random-key elk herd optimizer algorithm. This approach achieves over 100-fold improvement in thermal conductivity while reducing system weight without compromising performance or safety. Optimization using a Biased Random-Key Elk Herd Optimizer (BRKEHO) further refines expandable graphite distribution for balanced weight, efficiency, and safety. Python-based simulations and experiments validate that expandable graphite enhanced composites offer a promising path toward lightweight, efficient, and fire-safe battery thermal management systems designs for future electric vehicle applications.</p></div>","PeriodicalId":44939,"journal":{"name":"Heat Transfer","volume":"54 7","pages":"4745-4760"},"PeriodicalIF":2.6,"publicationDate":"2025-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145237310","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimization of Drying Conditions and Nutritional Characterization of Lotus Stem Flour","authors":"Ashoka S,&nbsp;M. L. Revanna,&nbsp;Vinay Kumar Pandey,&nbsp;Dileep K. C.,&nbsp;Sarvesh Rustagi","doi":"10.1002/htj.70016","DOIUrl":"https://doi.org/10.1002/htj.70016","url":null,"abstract":"<div>\u0000 \u0000 <p>Postharvest management of lotus stems (<i>Nelumbo nucifera</i>) is critically underemphasized in the food industry, leading to significant quality degradation and postharvest losses due to mechanical damage during handling, transportation, and valorization. This study aimed to optimize drying conditions through various pretreatments to enhance the processing and valorization efficiency of lotus stems and to characterize lotus stem flour in terms of its proximate composition, functional properties, and amino acid profile. This is the first study to optimize the drying conditions of lotus stem flour using citric acid and potassium metabisulfite (KMS) pretreatments, ensuring better retention of quality attributes. Lotus stems exhibit substantial variability, with weights ranging from 32.55 to 245.65 g, length from 18.00 to 44.35 cm, and width from 1.30 to 3.80 cm. Lotus stem slices dried at 70°C for 2 h yielded the highest percentage (26.50%), although higher temperatures generally resulted in decreased yields due to moisture loss and structural changes. The color attributes of lotus stem flour are affected by the drying temperature and anti-browning agents. The use of citric acid improved redness and yellowness, whereas potassium metabisulfite affected the color based on the concentration. Lotus stems pretreated with 2% KMS improved the lightness (<i>L</i>) by up to 18% (from 71.85 to 85.25), while the samples treated with 2% citric acid increased redness (<i>a</i>*) by approximately 57% (from 4.20 to 6.60) and yellowness (<i>b</i>*) by 33% (from 14.60 to 19.45), indicating enhanced color retention. Moreover, the lotus stem flour is characterized by moisture (6.30%), protein (7.60 g), carbohydrate (70.90 g), and fat (1.45 g), providing an energy value of 326.77 Kcal. It also contains appreciable amounts of essential minerals, including calcium, potassium, and magnesium, as well as negligible levels of toxic heavy metals. Flour is notable for its essential amino acids, particularly threonine, lysine, and leucine, and includes a range of nonessential and conditionally essential amino acids, contributing to its comprehensive nutritional profile. These findings highlight the potential of lotus stem flour as a functional ingredient for the food industry, particularly in the development of nutritionally enriched and shelf-stable products.</p>\u0000 </div>","PeriodicalId":44939,"journal":{"name":"Heat Transfer","volume":"54 7","pages":"4194-4206"},"PeriodicalIF":2.6,"publicationDate":"2025-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145237402","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thermal Performance of a PCM-Filled Finned Tube Heat Exchanger for Energy Recovery of Hot Exhaust Gases","authors":"Mohaddeseh Rajabzadeh,&nbsp;Amir Rahimi,&nbsp;Mohammad Sadegh Hatamipour","doi":"10.1002/htj.70021","DOIUrl":"https://doi.org/10.1002/htj.70021","url":null,"abstract":"<div>\u0000 \u0000 <p>This study explores the experimental and mathematical modeling of energy recovery from hot exhaust gases using a finned tube heat exchanger filled with paraffin. The experimental setup employs air as the heating fluid, water as the cooling fluid, and paraffin with a melting point of 68°C as the phase change material. Key parameters investigated include inlet air temperature, air mass flux during heating, and water mass during cooling. The system's thermal behavior is modeled mathematically by assuming heat accumulation in the paraffin-filled finned tubes. Numerical solutions of the equations are compared with experimental data, and dimensionless parameters are used to evaluate system performance under varying conditions. The model also examines the effects of structural features, such as fin height and the number of fins per unit tube length. The results show that increasing inlet air temperature and reducing air mass flux improve the heating and cooling efficiencies and overall system performance. Enhancing fin height from 0 to 1.5 cm and the number of fins from 0 to 20 within a 10 cm tube length leads to heating efficiency gains of 10.88% and 15%, respectively.</p>\u0000 </div>","PeriodicalId":44939,"journal":{"name":"Heat Transfer","volume":"54 7","pages":"4668-4688"},"PeriodicalIF":2.6,"publicationDate":"2025-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145237403","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}