{"title":"Optimizing Photovoltaic Thermal Collector Temperature with Varying Number of Collectors: A CFD Simulation Study","authors":"Zainal Arifin, Singgih Dwi Prasetyo, Rendy Adhi Rachmanto, Wibawa Endra Juwana, Eflita Yohana, Denny Widhiyanuriyawan","doi":"10.18280/ijht.410515","DOIUrl":"https://doi.org/10.18280/ijht.410515","url":null,"abstract":"ABSTRACT","PeriodicalId":13995,"journal":{"name":"International Journal of Heat and Technology","volume":"32 7","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135931623","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}
Suparni Setyowati Rahayu, Anak Agung Putu Susastriawan, Fredy Surahmanto, Muhammad Rio Firmansyah, Gugun Kurniawan
{"title":"Energy Efficiency of a Biomass Powered Dryer: An Analysis of Flue Gas Velocity Effects During Chili Drying","authors":"Suparni Setyowati Rahayu, Anak Agung Putu Susastriawan, Fredy Surahmanto, Muhammad Rio Firmansyah, Gugun Kurniawan","doi":"10.18280/ijht.410528","DOIUrl":"https://doi.org/10.18280/ijht.410528","url":null,"abstract":"","PeriodicalId":13995,"journal":{"name":"International Journal of Heat and Technology","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135930148","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}
The steam ejector, an essential auxiliary device, finds extensive use in various applications, including Multiple Effect Evaporation Desalination systems. The present study endeavored to evaluate the impact of different Converging-Diverging Nozzle placements. Initially, a vapor ejection was designed under certain conditions, utilizing one-dimensional compressible flow equations. Subsequently, the flow within the vapor ejection was simulated via a computational fluid dynamics (CFD) application, specifically the ANSYS program. The investigation entailed the selection of multiple nozzle locations and the examination of their effects under two scenarios: one with a constant back pressure for various suction pressures at each nozzle location, and the other with a fixed suction pressure coupled with several exit pressures. Results from the first scenario indicated that the optimal nozzle location was 5 mm from the commencement of the mixing area. For the second scenario, it was observed that closer proximity of the nozzle to the mixing area enhanced the performance of the steam ejector.
{"title":"Supersonic Nozzle Location in Steam Ejector Effect on the Mass Fraction and Vacuum of Second Fluid","authors":"Salim Ihsan Z., Jassim Najim A.","doi":"10.18280/ijht.410502","DOIUrl":"https://doi.org/10.18280/ijht.410502","url":null,"abstract":"The steam ejector, an essential auxiliary device, finds extensive use in various applications, including Multiple Effect Evaporation Desalination systems. The present study endeavored to evaluate the impact of different Converging-Diverging Nozzle placements. Initially, a vapor ejection was designed under certain conditions, utilizing one-dimensional compressible flow equations. Subsequently, the flow within the vapor ejection was simulated via a computational fluid dynamics (CFD) application, specifically the ANSYS program. The investigation entailed the selection of multiple nozzle locations and the examination of their effects under two scenarios: one with a constant back pressure for various suction pressures at each nozzle location, and the other with a fixed suction pressure coupled with several exit pressures. Results from the first scenario indicated that the optimal nozzle location was 5 mm from the commencement of the mixing area. For the second scenario, it was observed that closer proximity of the nozzle to the mixing area enhanced the performance of the steam ejector.","PeriodicalId":13995,"journal":{"name":"International Journal of Heat and Technology","volume":"4 ","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135931006","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}
This study presents an examination of mixed convection flow within a lid-driven square enclosure containing two cylinders, filled with Al 2 O 3 -water nanofluid. The finite volume method was employed, utilizing the Ansys-Fluent 14.5 software tool, to resolve the proposed mathematical model. The research was primarily centered on evaluating the impact of varying parameters such as the solid volume fraction (ϕ), Reynolds numbers (Re), and cylinder diameter (D) on heat transfer characteristics and entropy generation (St). As Re was increased, an enhancement in heat transfer was observed, accompanied by a reduction in St and Bejan number (Be). Augmenting ϕ resulted in increased heat transfer and Be, yet decreased St. A surge in D corresponded with elevated St and diminished Be. The investigation indicates that a cylinder diameter of D=0.1H optimizes convective heat exchange and minimizes St, with the average Nusselt number 𝑁𝑢̅̅̅̅ consistently decreasing as D escalates. These findings hold substantial potential for the optimization of thermal systems.
{"title":"Heat Transfer and Entropy Generation Minimization in a Lid-Driven Enclosure Filled with Nanofluid","authors":"Essma Belahmadi, Rachid Bessaїh","doi":"10.18280/ijht.410527","DOIUrl":"https://doi.org/10.18280/ijht.410527","url":null,"abstract":"This study presents an examination of mixed convection flow within a lid-driven square enclosure containing two cylinders, filled with Al 2 O 3 -water nanofluid. The finite volume method was employed, utilizing the Ansys-Fluent 14.5 software tool, to resolve the proposed mathematical model. The research was primarily centered on evaluating the impact of varying parameters such as the solid volume fraction (ϕ), Reynolds numbers (Re), and cylinder diameter (D) on heat transfer characteristics and entropy generation (St). As Re was increased, an enhancement in heat transfer was observed, accompanied by a reduction in St and Bejan number (Be). Augmenting ϕ resulted in increased heat transfer and Be, yet decreased St. A surge in D corresponded with elevated St and diminished Be. The investigation indicates that a cylinder diameter of D=0.1H optimizes convective heat exchange and minimizes St, with the average Nusselt number 𝑁𝑢̅̅̅̅ consistently decreasing as D escalates. These findings hold substantial potential for the optimization of thermal systems.","PeriodicalId":13995,"journal":{"name":"International Journal of Heat and Technology","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135930919","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}
Amid the escalating global focus on renewable energy, Multi-Energy Systems (MES) within distribution networks have emerged as crucial facilitators in addressing diverse energy requirements. This study delves into the collaborative interplay among energy sources, storage, and load within these networks, with a specific accent on electrical storage mechanisms. By evaluating interactions between renewable sources such as wind and solar, storage units, predominantly battery-based, and diverse loads like buildings and transportation, an integrated model is proposed. Both the first and second laws of thermodynamics are imposed as constraints on the MES operations within these networks. The effect of these thermodynamic laws, intertwined with electrical storage tactics, on overall thermodynamic efficiency is extensively detailed. Preliminary results have shown that, under certain circumstances, the adoption of well-defined source-storage-load synergistic strategies within distribution networks can significantly amplify the system's operational efficiency whilst maintaining a consistent energy supply. The insights derived from this investigation provide invaluable guidance to both designers and decision-makers in the realm of multi-energy systems within distribution networks, propelling the investigative nexus between thermodynamics and energy distribution systems.
{"title":"Synergistic Strategies in Multi-Energy Systems: Thermodynamic Constraints within Distribution Networks","authors":"Hua Bai, Wangying Kong, Zhengyong Wang, Lixia Tian","doi":"10.18280/ijht.410504","DOIUrl":"https://doi.org/10.18280/ijht.410504","url":null,"abstract":"Amid the escalating global focus on renewable energy, Multi-Energy Systems (MES) within distribution networks have emerged as crucial facilitators in addressing diverse energy requirements. This study delves into the collaborative interplay among energy sources, storage, and load within these networks, with a specific accent on electrical storage mechanisms. By evaluating interactions between renewable sources such as wind and solar, storage units, predominantly battery-based, and diverse loads like buildings and transportation, an integrated model is proposed. Both the first and second laws of thermodynamics are imposed as constraints on the MES operations within these networks. The effect of these thermodynamic laws, intertwined with electrical storage tactics, on overall thermodynamic efficiency is extensively detailed. Preliminary results have shown that, under certain circumstances, the adoption of well-defined source-storage-load synergistic strategies within distribution networks can significantly amplify the system's operational efficiency whilst maintaining a consistent energy supply. The insights derived from this investigation provide invaluable guidance to both designers and decision-makers in the realm of multi-energy systems within distribution networks, propelling the investigative nexus between thermodynamics and energy distribution systems.","PeriodicalId":13995,"journal":{"name":"International Journal of Heat and Technology","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135931284","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}
Peng Li, Yanli Ran, Xiumei Li, Ze Han, Yue Zhang, Liyong Zhang, Zhijun Du, Xinmiao Wu
ABSTRACT
{"title":"Thermal Equilibrium Analysis of Small-to-Medium River Ecosystems in Northern China under Multi-Factor Coupling and Decision-Making for Ecological Restoration","authors":"Peng Li, Yanli Ran, Xiumei Li, Ze Han, Yue Zhang, Liyong Zhang, Zhijun Du, Xinmiao Wu","doi":"10.18280/ijht.410519","DOIUrl":"https://doi.org/10.18280/ijht.410519","url":null,"abstract":"ABSTRACT","PeriodicalId":13995,"journal":{"name":"International Journal of Heat and Technology","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135931411","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}
A numerical investigation into the thermal-hydraulic performance of double elliptical twisted tubes fitted with twisted tape has been conducted. The fluid flow and heat transfer in the twisted double elliptical tubes heat exchanger were modeled utilizing Navier-Stokes, energy, and turbulence equations. The governing equations were resolved using ANSYS Fluent 23.1. Twisting ratios of 5 for twisted tubes and 4 for twisted tape were applied. The Reynolds number was varied within the range of 5000 to 25000. A counter-flow arrangement was established by inputting hot water into the inner tube and cold water into the outer tube. The introduction of twisted tape (TT) resulted in enhanced fluid and centrifugal force mixing near the wall, thereby significantly influencing heat transfer in this region. The study revealed that the heat transfer and performance were notably improved in comparison to a plain double-tube heat exchanger. Furthermore, the heat exchanger's effectiveness was found to increase by 75% at a Reynolds number of 5000.
{"title":"CFD Analysis for a Twisted Elliptical Double Tube Heat Exchangers Integrated with a Twisted Tape","authors":"Riyam Ali Khaled, Khudheyer S. Mushatet","doi":"10.18280/ijht.410520","DOIUrl":"https://doi.org/10.18280/ijht.410520","url":null,"abstract":"A numerical investigation into the thermal-hydraulic performance of double elliptical twisted tubes fitted with twisted tape has been conducted. The fluid flow and heat transfer in the twisted double elliptical tubes heat exchanger were modeled utilizing Navier-Stokes, energy, and turbulence equations. The governing equations were resolved using ANSYS Fluent 23.1. Twisting ratios of 5 for twisted tubes and 4 for twisted tape were applied. The Reynolds number was varied within the range of 5000 to 25000. A counter-flow arrangement was established by inputting hot water into the inner tube and cold water into the outer tube. The introduction of twisted tape (TT) resulted in enhanced fluid and centrifugal force mixing near the wall, thereby significantly influencing heat transfer in this region. The study revealed that the heat transfer and performance were notably improved in comparison to a plain double-tube heat exchanger. Furthermore, the heat exchanger's effectiveness was found to increase by 75% at a Reynolds number of 5000.","PeriodicalId":13995,"journal":{"name":"International Journal of Heat and Technology","volume":"1 2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135931412","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}
As the electronics industry gravitates towards smaller yet more powerful devices, the need to enhance traditional heat sink cooling capabilities without enlarging their footprint has become increasingly urgent. This necessity stems from the adverse effects of high temperatures on electronic performance and the limitations of traditional heat sinks' thermal transfer. This study addresses the challenge by investigating modifications to heat sink design, specifically through the strategic perforation of fins to increase their surface area, thereby improving heat dissipation without augmenting size. A series of lateral plate fins, perforated for increased surface area, were positioned on the base of a heat sink. The thermal performance of these modified heat sinks was then tested experimentally within a long, square cross-sectioned channel, facilitating forced air passage at manually controlled speeds. Three heat sink samples were compared under variable airflow rates to ascertain the cooling efficiency of the perforated fins. Three distinct rectangular heat sinks were utilized. The first featured holes of varying diameters arranged horizontally (PHS-HV), while the second had vertically varying diameters, with smaller ones at the top and larger ones at the bottom (PHS-VV). These perforated heat sinks were contrasted against a non-perforated heat sink under different thermal loads and Reynolds numbers. Results demonstrated enhanced heat dissipation, Nusselt number, and heat transfer coefficient in perforated fins compared to non-perforated ones. Notably, the use of different hole diameters in the same fin positively impacted heat dissipation, with horizontal diameter expansion (PHS-HV) outperforming vertical expansion (PHS-VV). The heat transfer improvement was 8.53% for PHS-HV and 4.36% for PHS-VV at Re 20000. Furthermore, perforation contributed to a decrease in heat sink mass compared to solid heat sinks, indicating cost and material savings. This study underscores the potential of strategic perforation in augmenting heat sink performance for next-generation electronics.
{"title":"Investigation of Heat Sinks with Different Perforation Patterns","authors":"Rana A. Al-Luhaibi, Ibrahim Thamer Nazzal","doi":"10.18280/ijht.410510","DOIUrl":"https://doi.org/10.18280/ijht.410510","url":null,"abstract":"As the electronics industry gravitates towards smaller yet more powerful devices, the need to enhance traditional heat sink cooling capabilities without enlarging their footprint has become increasingly urgent. This necessity stems from the adverse effects of high temperatures on electronic performance and the limitations of traditional heat sinks' thermal transfer. This study addresses the challenge by investigating modifications to heat sink design, specifically through the strategic perforation of fins to increase their surface area, thereby improving heat dissipation without augmenting size. A series of lateral plate fins, perforated for increased surface area, were positioned on the base of a heat sink. The thermal performance of these modified heat sinks was then tested experimentally within a long, square cross-sectioned channel, facilitating forced air passage at manually controlled speeds. Three heat sink samples were compared under variable airflow rates to ascertain the cooling efficiency of the perforated fins. Three distinct rectangular heat sinks were utilized. The first featured holes of varying diameters arranged horizontally (PHS-HV), while the second had vertically varying diameters, with smaller ones at the top and larger ones at the bottom (PHS-VV). These perforated heat sinks were contrasted against a non-perforated heat sink under different thermal loads and Reynolds numbers. Results demonstrated enhanced heat dissipation, Nusselt number, and heat transfer coefficient in perforated fins compared to non-perforated ones. Notably, the use of different hole diameters in the same fin positively impacted heat dissipation, with horizontal diameter expansion (PHS-HV) outperforming vertical expansion (PHS-VV). The heat transfer improvement was 8.53% for PHS-HV and 4.36% for PHS-VV at Re 20000. Furthermore, perforation contributed to a decrease in heat sink mass compared to solid heat sinks, indicating cost and material savings. This study underscores the potential of strategic perforation in augmenting heat sink performance for next-generation electronics.","PeriodicalId":13995,"journal":{"name":"International Journal of Heat and Technology","volume":"19 4","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135931431","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":"Effects of Synthetic Atmosphere and Strain Rate on NO Emission from a Biogas/Hydrogen Mixture in MILD Combustion","authors":"Hadef Amar, Mameri Abdelbaki, Aouachria Zeroual","doi":"10.18280/ijht.410509","DOIUrl":"https://doi.org/10.18280/ijht.410509","url":null,"abstract":"ABSTRACT","PeriodicalId":13995,"journal":{"name":"International Journal of Heat and Technology","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135931433","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}
Ganesh B. Agalave, Bhagyesh B. Deshmukh, Pradip R. Kulkarni
Efforts to augment the transition from conventional energy sources have encouraged a meticulous investigation into non-conventional alternatives, particularly solar energy for heating applications. This research explores the efficacy of a system integrating a Solar Flat Plate Collector (SFPC) and a Thermal Energy Storage (TES) system in heating applications, thereby offering an innovat ive solution to contemporary energy challenges. In the proposed system, paraffin wax, functioning as a phase change material (PCM), was utilized in quantities of 100 kg in the SFPC and 200 kg in the TES. The SFPC employed air as the heat transfer fluid, while water was used in the TES. Solar radiation served as the energy source, heating the PCM in the SFPC to a fusion temperature of 35℃. Heat was transported from the SFPC to the TES via the air, enabling effective energy storage. The heating application involved water circulation through the TES. Observations highlighted that the water exiting the TES for heating applications maintained a temperature of 36℃. This outcome demonstrates the potential of the system to heat fluids for various applications as needed, emphasizing its versatility and utility. To ensure the reliability of these findings, a Computational Fluid Dynamics (CFD) analysis was performed, validating the experimental results. The study concludes that the proposed integrated sys tem offers a viable solution for achieving desired fluid heating in diverse applications, thereby reiterating the potential of solar energy in non-conventional heating applications.
{"title":"Integration of Solar Flat Plate Collector and Thermal Energy Storage for Heating Applications: An Experimental Study","authors":"Ganesh B. Agalave, Bhagyesh B. Deshmukh, Pradip R. Kulkarni","doi":"10.18280/ijht.410524","DOIUrl":"https://doi.org/10.18280/ijht.410524","url":null,"abstract":"Efforts to augment the transition from conventional energy sources have encouraged a meticulous investigation into non-conventional alternatives, particularly solar energy for heating applications. This research explores the efficacy of a system integrating a Solar Flat Plate Collector (SFPC) and a Thermal Energy Storage (TES) system in heating applications, thereby offering an innovat ive solution to contemporary energy challenges. In the proposed system, paraffin wax, functioning as a phase change material (PCM), was utilized in quantities of 100 kg in the SFPC and 200 kg in the TES. The SFPC employed air as the heat transfer fluid, while water was used in the TES. Solar radiation served as the energy source, heating the PCM in the SFPC to a fusion temperature of 35℃. Heat was transported from the SFPC to the TES via the air, enabling effective energy storage. The heating application involved water circulation through the TES. Observations highlighted that the water exiting the TES for heating applications maintained a temperature of 36℃. This outcome demonstrates the potential of the system to heat fluids for various applications as needed, emphasizing its versatility and utility. To ensure the reliability of these findings, a Computational Fluid Dynamics (CFD) analysis was performed, validating the experimental results. The study concludes that the proposed integrated sys tem offers a viable solution for achieving desired fluid heating in diverse applications, thereby reiterating the potential of solar energy in non-conventional heating applications.","PeriodicalId":13995,"journal":{"name":"International Journal of Heat and Technology","volume":"79 ","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135931681","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}
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