Heat and Mass Transfer最新文献

{"title":"Study of a novel solar-driven internally cooled liquid desiccant system for hot and humid climates","authors":"","doi":"10.1007/s00231-024-03462-3","DOIUrl":"https://doi.org/10.1007/s00231-024-03462-3","url":null,"abstract":"<h3>Abstract</h3> <p>The current paper experimentally studied the performance of solar-driven internally cooled liquid desiccant system for hot and humid climates using CaCl₂ as a liquid desiccant. The system is designed to investigate the input conditions of the room by adjusting various air and solution variables. This internally cooled liquid desiccant system consists of the dehumidifier and regenerator in a single module and the regeneration of the solution is done by solar energy. The present study analyzes the effect of solution concentration, air mass flow rate and solution volume flow rate using different performance indices such as humidity reduction, moisture effectiveness, enthalpy effectiveness, and COP. The results demonstrate that the maximum moisture reduction of 4.2 g/kg d.a. is found at an airflow rate of 0.03195 kg/s, a solution volume flow rate of 12.5 LPM, and a solution concentration of 37%, while the maximum COP of 0.274 is obtained at an airflow rate of 0.0715 kg/s, a solution volume flow rate of 12.5 LPM, and a solution concentration of 37%. The maximum moisture and enthalpy effectiveness are obtained as 24.1% and 26.2%, respectively. The paper also presents the correlations for moisture and enthalpy effectiveness based on findings from experiments.</p>","PeriodicalId":12908,"journal":{"name":"Heat and Mass Transfer","volume":"55 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2024-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140075809","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Numerical and experimental research on natural convection condensation heat transfer","authors":"Bing Tan, Jiejin Cai","doi":"10.1007/s00231-024-03468-x","DOIUrl":"https://doi.org/10.1007/s00231-024-03468-x","url":null,"abstract":"<p>Natural convection condensation, with the advantage of high reliability and not requiring complex mechanical drive structures, is broadly used in industrial fields, such as chemical, nuclear power, automotive, etc. This work aims to investigate the heat transfer mechanism and evaluate the performance of natural convection condensation with the artificial neural network (ANN) method, correlation predictions, and the code based on the boundary theory. An empirical correlation was proposed based on the present experimental data with operating conditions in the pressure range of 0.2 MPa -0.6 MPa, subcooled temperature range of 11 K–45 K, and air mass fraction range of 0.0049–0.69. The empirical correlation was validated against a consolidated database, with 91% of the data reproduction falling within the error band of <span>(pm)</span> 30%. An ANN model was put forward with training, validation, and testing using the present experimental data, which yields an error of <span>(pm)</span> 5% in the present test data. When the trained model was utilized to reproduce the additional database, all the data fell within an <span>(pm)</span> 11% error band. Finally, a side-by-side comparison in heat transfer coefficient reproduction was conducted among those rapidly computational methods, and the ANN model turned out to have the best performance.</p>","PeriodicalId":12908,"journal":{"name":"Heat and Mass Transfer","volume":"32 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2024-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140026169","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental study of multidimensional wire-plate/sintered hybrid mini heat pipes for electronics","authors":"Marcia B. H. Mantelli, João V. C. Batista, Juan P. F. Mera","doi":"10.1007/s00231-024-03467-y","DOIUrl":"https://doi.org/10.1007/s00231-024-03467-y","url":null,"abstract":"<p>The experimental study concerning new two and three dimensional mini heat pipes, proposed for cooling electronic components in printed circuit boards is presented. These heat pipes can capture the heat from electronic components and conduct it to the cabinet wall, through the narrow spaces available between boards. As the location and dissipation of the electronic components vary, several different heat pipes are necessary for a complex electronic equipment, which should operate at different temperatures and orientations. A hybrid wick structure, composed by sintered copper powder and wire-plate technologies along the device are proposed. Four different types of hybrid mini heat pipes, in up to three generations, were designed and constructed, using diffusion bonding fabrication technique. Two different testing setups were developed. First, the thermal performance of the hybrid heat pipes was accessed, resulting in the selection of the appropriated working fluid and its volume. Second, the devices were tested in rigs that mimic actual electronic equipment geometries and operational conditions. The several hybrid multidimensional heat types worked well, even against gravity. Besides, the present work shows that the wire-plate wick structure, up to this date considered only in academic studies, resulted in very flexible heat pipes, able to start up easily, in several adverse geometric and gravitational conditions, especially when combined with more conventional technologies, such as sintered porous media. Besides, the fabrication process developed that includes diffusion bonding, can be considered a novelty.</p>","PeriodicalId":12908,"journal":{"name":"Heat and Mass Transfer","volume":"36 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2024-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140018865","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Application of a phase change numerical model to the simulation of freezing and thawing of wrapped foods","authors":"Beata Anwajler, Daniel Smykowski, Jacek Kasperski","doi":"10.1007/s00231-024-03452-5","DOIUrl":"https://doi.org/10.1007/s00231-024-03452-5","url":null,"abstract":"<p>The process of heat transfer is one of the most important issues in the food industry and plays a crucial role in the storage of frozen foods. The main objective in this field is to extend the storage time, which can be achieved by limiting the heat transfer between the ambient air and the frozen food product. In this paper, the authors applied a numerical model of the phase change process to simulate the freezing and thawing process of a package wrapped with compressible multilayer polymer thermal insulation. The model was solved in COMSOL Multiphysics program and verified with experimental results with satisfactory agreement. Based on the performed simulations and experiments, it was proved that the freezing time of the tylose package is almost the same regardless of the applied film, while the thawing time of the package strongly depends on the type of film—transparent, opaque or metallized. The use of transparent film allows to extend the maximum thawing time of food products by 2 times, the use of opaque film—by about 3.7 times, and the use of metallized film—by about 4.1 times.</p>","PeriodicalId":12908,"journal":{"name":"Heat and Mass Transfer","volume":"134 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140010476","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Heat transfer on impingement cooled meshing spur gears: Experimental comparison of into-mesh, out-of-mesh and inclined impingement methods","authors":"Emre Ayan, Christian Kromer, Corina Schwitzke, Hans-Jörg Bauer","doi":"10.1007/s00231-024-03464-1","DOIUrl":"https://doi.org/10.1007/s00231-024-03464-1","url":null,"abstract":"<p>Oil jet impingement cooling is the standard approach to cool high-speed high-power gears. The heat transfer between oil jets and gears is experimentally investigated in this paper. The three established methods of oil jet impingement cooling -into-mesh, out-of-mesh and inclined impingement on one of the gears- are studied. Heat transfer coefficients for these methods are experimentally determined. A loss correction approach is implemented for the evaluation of measurements. For the inclined impingement method, heat transfer on the non-impinged gear and the influence of meshing on the heat transfer coefficient are investigated. Gear meshing has an insignificant effect on the average heat transfer coefficient over the gear tooth. However, the spatial distribution of the heat transfer coefficient depends on the meshing configuration. Significant cooling on the non-impinged gear is observed with the inclined impingement method. The inclined impingement method is superior to the into-mesh and out-of-mesh methods at all measured operating points.</p>","PeriodicalId":12908,"journal":{"name":"Heat and Mass Transfer","volume":"170 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2024-02-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140011146","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparison of thermal conductivities of polypropylene fibers and fibrils","authors":"Hao Yin, Chenhan Liu, Bin Wang, Yong Li, Xue Hu, Junyao Yin, Jinbo Liu, Gutian Zhao, Juekuan Yang","doi":"10.1007/s00231-024-03463-2","DOIUrl":"https://doi.org/10.1007/s00231-024-03463-2","url":null,"abstract":"<p>In this work, we compared thermal conductivities of polypropylene fibers and fibrils. The polypropylene fibers were melt spun, and oriented by solid-state drawing. Both wide-angle X-ray scattering and sonic velocity measurements were performed to determine the orientation of fibers. The thermal conductivities of fibers were measured via direct electrical heating method, and that of fibrils were measured via thermal bridge method. Our results show that the thermal conductivity of polypropylene fibers increases linearly with their sonic velocity. This suggests we can use the sonic velocity to characterize the thermal conductivity of semicrystalline polymers. Our results also indicate the average thermal conductivity of fibrils is close to that of fibers. This implies that the low thermal conductivity of polymer fibers is due to the low thermal conductivity of fibrils, instead of thermal resistance between fibrils.</p>","PeriodicalId":12908,"journal":{"name":"Heat and Mass Transfer","volume":"2016 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2024-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139977958","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Drying properties, color characteristics, microstructure, and modeling of ginger cubes dried using electrohydrodynamic, electrohydrodynamic-hot air, and hot air methods","authors":"Ahmet Polat, Nazmi Izli","doi":"10.1007/s00231-024-03459-y","DOIUrl":"https://doi.org/10.1007/s00231-024-03459-y","url":null,"abstract":"<p>This study investigates the drying of ginger cubes using three different techniques: electrohydrodynamic drying, electrohydrodynamic-hot air drying, and hot air drying. The main objective is to assess how these drying methods affect drying times, effective diffusion coefficients, color, and microstructure. Additionally, the study includes fitting ten different thin-layer models to the experimental data for mathematical analysis. It was observed that increasing temperature and voltage values led to a reduction in the drying times of the ginger samples. After conducting statistical tests, it was determined that the Midilli et al. and Wang and Singh models were the most suitable for describing the experimental drying curves. Effective diffusion coefficient values increased with the rise in temperature and voltage values. The <i>L*</i> values of the dried ginger samples decreased due to temperature and voltage applications. Notably, ginger samples dried using the electrohydrodynamic method exhibited better preservation of their original appearance, particularly in terms of microstructure and starch particle integrity, compared to other drying methods. The findings of the study suggest that integrating electrohydrodynamic technology with hot air drying reduces overall drying time. This innovative approach shows promise for producing high-quality end products in the future.</p>","PeriodicalId":12908,"journal":{"name":"Heat and Mass Transfer","volume":"21 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2024-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139977962","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Energy correlation of heat transfer for drag reduction surfactant solution in a double pipe heat exchanger","authors":"Bon A. A. Ramamonjisoa, Aycan Altun, Osman Nuri Şara","doi":"10.1007/s00231-024-03461-4","DOIUrl":"https://doi.org/10.1007/s00231-024-03461-4","url":null,"abstract":"<p>In the present study, the effects of surfactant solutions on pressure drop properties and heat transfer characteristics in a double pipe heat exchanger have been investigated. An ionic surfactant (SDS) and two nonionic surfactants (NP-10 and Tween 80) solutions with 0.2 wt% are utilized at different flow rates. The results show that pressure drops for surfactant solutions are lower than those for water at equivalent flow rates. NP-10 demonstrates high drag reduction values, reaching a maximum of approximately 15%, whereas Tween 80 has lower drag reduction values, which vary according to the flow rate. Besides, Nusselt number for water in this study reveals a satisfactory agreement with the predictions derived from the Dittus-Boelter equation with a difference of 2.1%. While NP-10 and Tween 80 addition cause the Nusselt number to decline, SDS does not significantly alter it when compared to water. Energy correlations with high R² values have been developed using experimental data for water and surfactant solutions. Furthermore, enhancement factors (η), the ratio of heat transferred at constant pumping power with and without surfactant, have been calculated. The η values vary within a range of 0.8‒1.1 depending on the flow rate, and for SDS solution, these values are above 1 when the Reynolds number is in the range of 13000–25000. In the case of NP-10 and Tween 80 solution, the η values are below 1 for the whole flow rate range.</p>","PeriodicalId":12908,"journal":{"name":"Heat and Mass Transfer","volume":"17 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2024-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139949466","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigation of the hydrodynamic and thermodynamic behavior of the liquid jet quenching process","authors":"","doi":"10.1007/s00231-024-03447-2","DOIUrl":"https://doi.org/10.1007/s00231-024-03447-2","url":null,"abstract":"<h3>Abstract</h3> <p>Liquid jet quenching of metals is typically adopted to achieve specific material properties of metals, thereby making them suitable for advanced engineering applications. In this process, a metal plate is heated and cooled rapidly by impinging water jets. The temperature history during cooling leads to a microstructural transformation thereby improving the material properties such as hardness. During liquid jet quenching, since the plate surface temperature is above the Leidenfrost temperature, the boiling heat transfer dominates. This is associated with an intense cooling and water vapor generation, where the Leidenfrost effect impedes the immediate wetting of the surface. The resulting uneven cooling over the plate surface tends to potential deformation and cracking. To control this process, a detailed understanding of the spatial and the temporal heat transfer behavior is imperative. Experiments in this context are limited and therefore investigating the conjugate heat transfer process is to be combined with a multi-phase numerical model. The two-phase numerical model based on the Euler-Euler approach is developed and validated to simulate the jet quenching of a stationary plate considering all the boiling regimes within a single framework. This model consists of two phases, the liquid water which is the continuous phase (primary) and the water vapor modeled as the dispersed phase (secondary). In this study, a circular water jet (tap water) impact is considered and the plate materials under investigation are aluminum alloy (Al-alloy) and stainless steel (St-steel). Experiments are performed using infrared and high-speed imaging. The validated numerical model provides the technical parameters such as wetting front behavior, heat flux, HTC (heat transfer coefficient) etc. The influence of the jet Reynolds number and the plate material properties on the heat transfer is analysed. The study emphasizes that the plate material has a significantly higher influence on the heat transfer during jet quenching.</p> <span> <h3>Graphical abstract</h3> <p><span> <span> <img alt=\"\" src=\"https://static-content.springer.com/image/MediaObjects/231_2024_3447_Figa_HTML.png\"/> </span> </span></p> </span>","PeriodicalId":12908,"journal":{"name":"Heat and Mass Transfer","volume":"259 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2024-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139926111","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Drying of Curcuma longa L. slices by refractance window: Effect of temperature on thermodynamic properties and mass transfer parameters","authors":"Natasha Cunha, Luiza Helena Meller da Silva, Antonio Manoel da Cruz Rodrigues","doi":"10.1007/s00231-024-03455-2","DOIUrl":"https://doi.org/10.1007/s00231-024-03455-2","url":null,"abstract":"<p><i>Curcuma longa</i> L. rhizomes (CL) are aromatic spices known for their natural dye properties. These rhizomes contain considerate quantities of nutrients and bioactive compounds. Nevertheless, due to their perishable nature, they necessitate water removal process. This research aims to evaluate the adequacy of the analytical model established by Dincer and Dost in 1995, using experimental data from the Refractive Window (RW) drying method, focusing on solid samples in the flat plate configuration of <i>Curcuma longa</i> L. A comparative analysis will be carried out with the model devised by Crank in 1975, which relies on the traditional solution of Fick's second law. The primary objective is to determine the mass transfer parameters and the thermodynamic characteristics relevant to the drying procedure. The drying process for the samples was observed to be relatively rapid. In their natural state, the samples had a moisture content of 80.71 ± 1.12% (on a dry basis). According to the Dincer and Dost model, the moisture diffusivity ranged from 0.85 × 10^–8 m² s⁻¹ to 2.15 × 10^–8 m² s⁻¹, and the mass transfer coefficient varied from 1.60 × 10^–6 to 1.12 × 10^–6 m s⁻¹. The entropy value (ΔS) obtained was negative (ΔS &lt; 0). The thermodynamic properties indicated a non-spontaneous process with positive values for enthalpy and Gibbs free energy, along with negative values for entropy.</p>","PeriodicalId":12908,"journal":{"name":"Heat and Mass Transfer","volume":"3 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2024-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139766372","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}