Frontiers in thermal engineering最新文献

{"title":"Hydrogen production using advanced reactors by steam methane reforming: A review","authors":"A. Ganguli, Viraj Bhatt","doi":"10.3389/fther.2023.1143987","DOIUrl":"https://doi.org/10.3389/fther.2023.1143987","url":null,"abstract":"The present review focuses on the current progress on harnessing the potential of hydrogen production by Methane Steam Reforming (MSR). First, based on the prominent literature in last few years, the overall research efforts of hydrogen production using different feed stocks like ethanol, ammonia, glycerol, methanol and methane is presented. The presented data is based on reactor type, reactor operating conditions, catalyst used and yield of hydrogen to provide a general overview. Then, the most widely used process [steam methane reforming (SMR)/methane steam reforming (MSR)] are discussed. Major advanced reactors, the membrane reactors, Sorption Enhanced methane steam reforming reactors and micro-reactors are evaluated. The evaluation has been done based on parameters like residence time, surface area, scale-up, coke formation, conversion, space velocity and yield of hydrogen. The kinetic models available in recently published literature for each of these reactors have been presented with the rate constants and other parameters. The mechanism of coke formation and the rate expressions for the same have also been presented. While membrane reactors and sorption enhanced reactors have lot of advantages in terms of process intensification scale-up to industrial scale is still a challenge due to factors like membrane stability and fouling (in membrane reactors), decrease in yield with increasing WHSV (in case of Sorption Enhanced Reactors). Micro-reactors pose a higher potential in terms of higher yield and very low residence time in seconds though the volumes might be substantially lower than present industrial scale conventional reactors.","PeriodicalId":73110,"journal":{"name":"Frontiers in thermal engineering","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47328917","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":"Specialty grand challenge: Thermal energy storage and conversion","authors":"B. Saha, Tahmid Hasan Rupam","doi":"10.3389/fther.2023.1157794","DOIUrl":"https://doi.org/10.3389/fther.2023.1157794","url":null,"abstract":"The world is experiencing rapid technological advancement on a multidimensional scale but at the expense of its environmental sustainability. In this ever-developing world, the hunger for energy is increasing day by day. Natural resources for energy production, such as fossil fuels, are on the brink of extinction due to their extensive use to meet this ever-growing demand for energy. Most of the fossil fuel-burned energy in today’s world is spent on the continuous production of drinkable water, heating, cooling applications, and power generation (Rupam et al., 2022a). Along with irreversible resource exhaustion, burning fossil fuels causes excessive emissions of greenhouse gases and other pollutants responsible for global warming. Keeping in mind the catastrophic effects of the rising temperature, in recent times, there has been a global urge for the development of energy-saving, eco-friendly systems for water production, HVAC applications, power generation, etc. Although renewables are advancing at a fast pace, it has not yet reached a satisfactory level where all the energy-intensive systems can be operated with that. Apart from that, renewables are overly dependent on environmental constraints. For example, at night time or on gloomy days, solar energy cannot be harvested, or the energy conversion rate of photovoltaics drastically decreases. On the other hand, when there is plenty of sunshine, solar photovoltaics produce more energy than the required amount at that time. Most often, this surplus energy ends up being wasted due to the lack of proper energy storage or conversion systems. In this regard, thermal energy conversion and storage systems can offer reasonably realistic alternatives due to their multifaceted features. Thermal energy storage systems can store surplus energy in favorable conditions and provide clean and affordable energy in adverse situations in various forms such as heating, cooling, drinking water, or even power generation. Contrarily, thermal energy conversion systems can pave the way to further increase the share of renewables in the energy mix and play a significant role in the future decarbonized society. Globally, there are a variety of thermal energy storage and conversion (TESC) technologies currently being extensively researched. Figure 1 illustrates some of the most prominent technologies associated with the vast research field of TESC. Although the TESC technologies hold enormous potential, their utilization is subjected to various challenges associated with them. Depending on the applications and working conditions, certain obstacles can come forward, and to overcome those, efforts from both science and engineering fields are required. This speciality grand challenge aims to address the major drawbacks and discuss future research directions for overcoming these challenges associated with current TESC technologies. OPEN ACCESS","PeriodicalId":73110,"journal":{"name":"Frontiers in thermal engineering","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-03-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46578045","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 meniscus curvature on phase-change performance during capillary-enhanced filmwise condensation in porous media","authors":"Ruisong Wang, D. Antao","doi":"10.3389/fther.2023.1131363","DOIUrl":"https://doi.org/10.3389/fther.2023.1131363","url":null,"abstract":"Sustainably enhancing condensation heat transfer performance is a major challenge in thermal management and energy systems, since typical condensation enhancement methods (i.e., dropwise condensation with low surface energy coatings) have limited lifetime/durability, restricted compatibility with working fluids, and sustainability concerns due to the coating composition (e.g., fluorinated compounds). The robust and scalable capillary-enhanced filmwise condensation mode presented in this work demonstrates high heat transfer coefficients for water and low surface tension liquids condensing in a porous wick. Thin porous wicks offer the highest enhancements in heat transfer, however such thin porous wicks have thickness-dependent permeability, and the effective liquid thickness of the wick depends on the shape of the liquid-vapor interface. In this study, we leverage a spatially-discretized porous media model to characterize the effect of the wick thickness on condensation heat transfer performance. The model uses a spatially-varying permeability that depends on the local liquid-vapor interface shape/curvature and the resulting effective wick thickness. We apply this model to investigate the correlation between the heat transfer enhancement and various geometric factors, which enables the design of optimal porous structures for relevant phase-change application. We also predict favorable enhancement in condensation performance with a few common hydrocarbon and fluorocarbon fluid refrigerants. This study provides fundamental insight into the effects of the shape of the liquid-vapor interface on the phase-change performance in the capillary-enhanced filmwise condensation mode.","PeriodicalId":73110,"journal":{"name":"Frontiers in thermal engineering","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48804340","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 methane supplementation on the performance, vibration and emissions characteristics of methane-diesel dual fuel engine","authors":"G. Tripathi, Sarthak Nag, Priybrat Sharma, A. Dhar","doi":"10.3389/fther.2023.1101333","DOIUrl":"https://doi.org/10.3389/fther.2023.1101333","url":null,"abstract":"The increasing energy demands, especially in transportation sector, and the challenges of excess pollution and environmental degradation caused due to the conventional fuels, as well as their limited availability has highlighted the need to look for alternative fuels to sustain future needs. Methane is capable of catering to these demands due to its wide availability, both in renewable and non-renewable energy sources. The present work explores the effect of methane supplementation on the performance and emission characteristics as well as the vibrations in internal combustion engines. A four-stroke compression ignition engine is modified to run as a methane-diesel dual fuel engine where methane is inducted through intake manifold and diesel is directly injected into cylinder. Tests are performed by varying engine load and methane energy levels up to 75%. Our study shows that the participation of methane at lower load conditions is weak due to its higher auto ignition temperature and higher calorific value. The emissions, particularly CO and NO, are observably higher at 75% load conditions due to the efficient combustion and higher temperature at higher load conditions. The vibration studies on the dual fuel combustion indicates that the introduction of methane also suppresses the frequency spectrum of combustion noise and reduces the ringing intensity level of vibration for complete spectrum of engine loads, with the effect being prominent at higher loads. Overall, our results suggests that combustion of methane in dual fuel diesel engine shows distinct characteristics at contrasting load conditions.","PeriodicalId":73110,"journal":{"name":"Frontiers in thermal engineering","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44718527","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":"Electric field assisted reduction of NOx emission: A numerical study","authors":"Sheikh F. Ahmed, A. C. Aghdam, Jackson Pleis, R. Geiger, T. Farouk","doi":"10.3389/fther.2022.1079789","DOIUrl":"https://doi.org/10.3389/fther.2022.1079789","url":null,"abstract":"The paper reports simulation results on the influence of a direct-current driven radial electric field on the emission characteristics; especially NOx and CO of a premixed methane/air laminar jet flame. A multi-physics computational model is developed in the OpenFOAM framework to simulate electric-field-coupled premixed combustion process. The computational framework consists of coupled species, momentum and energy conservation together with a Poisson’s equation solver to resolve the electric field distribution. Electron and ion conservation equations are resolved to consider the ionic wind body force in the momentum conservation equation and the associated possible electric field distortion due to the space charge distribution. The simulations are conducted for a stochiometric and fuel rich condition and over a range of jet flow rates for a configuration representative of a test-scale experimental setup. The model predictions show that for an applied voltage of 50 kV, the flame structure changes significantly for both the stoichiometric and fuel rich conditions. The flame is stretched significantly by the electric field due to ionic wind. For the fuel rich condition, the ionic wind allows additional mixing of the fuel rich stream with the surrounding air and drastically altering the flame structure. The electric field was found to reduce the NOx emission significantly for both stoichiometric and rich conditions. Over the entire range of flowrate conditions, the stochiometric fuel-oxidizer mixture showed a decrease in maximum NOx by a factor of 1.6 in presence of electric field. For the fuel rich case, however as the flow rate is increased, the NOx reduction factor decreased from 12.0 to 1.6. For CO emissions, the presence of electric field reduces the concentration under fuel rich conditions and vice versa for the stoichiometric flame. The role of kinetics is analyzed and discussed.","PeriodicalId":73110,"journal":{"name":"Frontiers in thermal engineering","volume":"2 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44904297","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":"A design approach for thermal enhancement in heat sinks using different types of fins: A review","authors":"A. Gaikwad, A. Sathe, S. Sanap","doi":"10.3389/fther.2022.980985","DOIUrl":"https://doi.org/10.3389/fther.2022.980985","url":null,"abstract":"This article provides an in-depth overview of thermal heat sink design and optimization. Heat transfer enhancement strategies are discussed in detail, followed by fin design trends and geometries, and a discussion on different fin configurations and their merits is also presented. Important results and findings of experiments concerning the design and optimization of fin geometries have been summarized. For complex heat dissipation applications, researchers have been studying different fin arrangements especially, inclined fins, to maximize the performance of the heat sinks. Along with innovative fin designs, microchannels for heat dissipation are gaining attention due to their. Recent advances in this domain have been discussed. New components are becoming more compact and advanced as a result of technological breakthroughs in electronics and control systems; hence, the use and optimization of heat sinks for modern applications are also discussed in this article.","PeriodicalId":73110,"journal":{"name":"Frontiers in thermal engineering","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47689719","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":"Editorial: Thermal management of electrochemical energy devices or systems","authors":"Zhiguo Qu, P. Ming, Kui Jiao, M. Secanell, Xianguo Li","doi":"10.3389/fther.2022.1121606","DOIUrl":"https://doi.org/10.3389/fther.2022.1121606","url":null,"abstract":"MOE Key Laboratory of Thermo-Fluid Science and Engineering, School of Energy and Power Engineering, Xi’an Jiaotong University, Xi’an, Shaanxi, China, School of Automotive Studies and Clean Energy Automotive Engineering Center, Tongji University (Jiading Campus), Shanghai, China, State Key Laboratory of Engines, Tianjin University, Tianjin, China, Department of Mechanical Engineering, University of Alberta, Edmonton, AB, Canada, Department of Mechanical and Mechatronics Engineering, University of Waterloo, Waterloo, ON, Canada","PeriodicalId":73110,"journal":{"name":"Frontiers in thermal engineering","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46344494","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 study on heat transfer characteristics of steam underwater direct-contact condensation","authors":"Chen Qian, L. Hui, Li Dongyang, Wen Jiming, L. Yong, Xiao Qi, Tan Sichao","doi":"10.3389/fther.2022.1030998","DOIUrl":"https://doi.org/10.3389/fther.2022.1030998","url":null,"abstract":"Introduction: The direct-contact condensation (DCC) of steam under water injection is the basic thermodynamic process of the bubble deaerator. In order to understand the complex coupling behavior of strong turbulence and fast phase-change heat transfer involved in the process. Methods: This study uses a visualized method and convective heat transfer model. Results: Since the contact area is affected by steam injection flow and sub-cooled degree is affected simultaneously, the trend of the condensation heat-transfer coefficient depends on the degree of their respective effects under each condition, and the maximum variation of the coefficient exceeds 104 W/m2.°C. Moreover, they still effect the period of steam plume, and the maximum variation of the period was beyond 80 ms. Discussion: Calculated the average condensation heat transfer coefficient and then produces the variation law of heat transfer coefficient under various conditions in one steam plume evolution period.","PeriodicalId":73110,"journal":{"name":"Frontiers in thermal engineering","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45711789","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":"Design of a temperature-feedback controlled automated magnetic hyperthermia therapy device.","authors":"Anirudh Sharma,&nbsp;Avesh Avinash Jangam,&nbsp;Julian Low Yung Shen,&nbsp;Aiman Ahmad,&nbsp;Nageshwar Arepally,&nbsp;Hayden Carlton,&nbsp;Robert Ivkov,&nbsp;Anilchandra Attaluri","doi":"10.3389/fther.2023.1131262","DOIUrl":"https://doi.org/10.3389/fther.2023.1131262","url":null,"abstract":"<p><strong>Introduction: </strong>Magnetic hyperthermia therapy (MHT) is a minimally invasive adjuvant therapy capable of damaging tumors using magnetic nanoparticles exposed radiofrequency alternating magnetic fields. One of the challenges of MHT is thermal dose control and excessive heating in superficial tissues from off target eddy current heating.</p><p><strong>Methods: </strong>We report the development of a control system to maintain target temperature during MHT with an automatic safety shutoff feature in adherence to FDA Design Control Guidance. A proportional-integral-derivative (PID) control algorithm was designed and implemented in NI LabVIEW^®. A standard reference material copper wire was used as the heat source to verify the controller performance in gel phantom experiments. Coupled electromagnetic thermal finite element analysis simulations were used to identify the initial controller gains.</p><p><strong>Results: </strong>Results showed that the PID controller successfully achieved the target temperature control despite significant perturbations.</p><p><strong>Discussion and conclusion: </strong>Feasibility of PID control algorithm to improve efficacy and safety of MHT was demonstrated.</p>","PeriodicalId":73110,"journal":{"name":"Frontiers in thermal engineering","volume":"3 ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10026551/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9181787","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":"Water sorption-based thermochemical storage materials: A review from material candidates to manufacturing routes","authors":"A. Palacios, M. Navarro, C. Barreneche, Yulong Ding","doi":"10.3389/fther.2022.1003863","DOIUrl":"https://doi.org/10.3389/fther.2022.1003863","url":null,"abstract":"A comprehensive and updated review is provided in this article, with a focus on water sorption-based thermochemical storage (WSTCS) materials, covering materials and their manufacturing routes. The state of the art of 22 most relevant salt hydrates is classified into seven groups (bromides, sulphates, carbonates, chlorides, nitrates, hydroxides, and sulphides) and studied as candidates. This is followed by a discussion on TCS material manufacturing, covering both conventional (shaping, pelletizing, etc.) and more advanced routes (e.g., extrusion, 3D printing, encapsulation, etc.). Finally, concluding remarks are presented, including limitations and future potentials for TCS research.","PeriodicalId":73110,"journal":{"name":"Frontiers in thermal engineering","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47617352","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}