Pub Date : 2026-02-01DOI: 10.1016/j.csite.2026.107780
Kamil Abbas, Lele Yang, Ghulam Rasool, Peilin Zhu, Ming Wang
Efficient control of coupled heat and mass transfer in hybrid nanofluids is important for advanced cooling and thermal energy systems. The study numerically investigates micropolar GO–TiO2 hybrid nanofluid flow and thermo-solutal transport in an inclined lid driven cavity. The flow is assumed to be two-dimensional, laminar, and incompressible with constant thermophysical and micropolar properties along with a homogeneous Darcy porous medium under a uniform inclined magnetic field. The Hamilton–Crosser model was employed to account for the blade-shaped nanoparticles, owing to their superior thermal conductivity. Micropolar fluid theory was implemented to observe vortex viscosity and microrotation effects. The effects of thermophoresis, Brownian motion, thermal radiation, and magnetic field inclination, were analyzed through self-developed MATLAB code to implement Finite Volume Method (FVM). The parametric sweep revealed that reduction in Darcy number from 10-1 to 10-3 resulted in elevated flow resistance which led to lowering of heat transfer by about 5% and concentration buildup by 8%. Increasing the Hartmann number from 20 to 80 enhances the heat transfer rate by about 6%. The micropolar parameter elevation from 1 to 7 further suppressed the heat transfer rate by roughly 12%. Overall, the results suggests that combined influence of micropolarity, magnetic fields, porous resistance, and radiative effects offer valuable insights into transport enhancement in hybrid nanofluids, which is relevant for the design of compact cooling devices and thermal energy conversion components.
{"title":"A Hybrid-Differencing Finite Volume Method for Vortex Viscosity Controlled Thermosolutal Micropolar Nanofluid Flow in Darcy Medium with Brownian Effects","authors":"Kamil Abbas, Lele Yang, Ghulam Rasool, Peilin Zhu, Ming Wang","doi":"10.1016/j.csite.2026.107780","DOIUrl":"https://doi.org/10.1016/j.csite.2026.107780","url":null,"abstract":"Efficient control of coupled heat and mass transfer in hybrid nanofluids is important for advanced cooling and thermal energy systems. The study numerically investigates micropolar GO–TiO<ce:inf loc=\"post\">2</ce:inf> hybrid nanofluid flow and thermo-solutal transport in an inclined lid driven cavity. The flow is assumed to be two-dimensional, laminar, and incompressible with constant thermophysical and micropolar properties along with a homogeneous Darcy porous medium under a uniform inclined magnetic field. The Hamilton–Crosser model was employed to account for the blade-shaped nanoparticles, owing to their superior thermal conductivity. Micropolar fluid theory was implemented to observe vortex viscosity and microrotation effects. The effects of thermophoresis, Brownian motion, thermal radiation, and magnetic field inclination, were analyzed through self-developed MATLAB code to implement Finite Volume Method (FVM). The parametric sweep revealed that reduction in Darcy number from 10<ce:sup loc=\"post\">-1</ce:sup> to 10<ce:sup loc=\"post\">-3</ce:sup> resulted in elevated flow resistance which led to lowering of heat transfer by about 5% and concentration buildup by 8%. Increasing the Hartmann number from 20 to 80 enhances the heat transfer rate by about 6%. The micropolar parameter elevation from 1 to 7 further suppressed the heat transfer rate by roughly 12%. Overall, the results suggests that combined influence of micropolarity, magnetic fields, porous resistance, and radiative effects offer valuable insights into transport enhancement in hybrid nanofluids, which is relevant for the design of compact cooling devices and thermal energy conversion components.","PeriodicalId":9658,"journal":{"name":"Case Studies in Thermal Engineering","volume":"41 1","pages":""},"PeriodicalIF":6.8,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146098224","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-01DOI: 10.1016/j.csite.2026.107729
Lingen Chen , Shuangshuang Shi , Yanlin Ge , Huijun Feng
An endoreversible three-reservoir non-isothermal chemical-pump (NICP) cycle is modeled by equivalent combined-cycle method, taking it as combined-cycle of endoreversible two-reservoir NICP driven by endoreversible two-reservoir non-isothermal chemical-engine. Applying finite-time thermodynamics and considering heat-and-mass-transfer coupling effect following Lewis criterion, 3-D graphical illustration of NICP cycle is obtained, and expressions of rate of energy pumping (REP) and vector coefficients-of-performance (COPs) are derived. Effects of some fixed parameters on general relationship surface of REP and COPs are analyzed. At a fixed total mass-transfer coefficient, optimal distribution of mass-transfer coefficient is studied, and optimal relationship surface of three-reservoir NICP is obtained. Influence of working fluid physical properties on performance of three-reservoir NICP is analyzed and compared. 3-D graphical illustrations for three-reservoir NICP are conducive to understanding cycle processes. Results indicate that as both heat-transfer flow rate and mass-transfer flow rate increase, REP increases and vector COPs decrease. 3-D optimal relationship surface of REP and vector COPs is monotonically decreasing. Compared with three-reservoir heat-pump, REP of three-reservoir NICP increases by 114.16 %, while vector COP decreases by 4.43 %. Compared with three-reservoir isothermal-chemical-pump, REP of three-reservoir NICP increases by 896.91 %, and vector COP increases by 135.24 %. Mass-transfer process has detrimental effect on heat-transfer process. The physical properties of working fluid have no qualitative influence on performance of three-reservoir NICP, but only quantitative influence. General and optimal relationships of three-reservoir NICP include five special cases: those of two- and three-reservoir heat-pumps with Newton's heat-transfer law, those of two- and three-reservoir isothermal-chemical-pumps with diffusive mass-transfer law, and that of two-reservoir NICP following Lewis criterion. Main contributions herein are establishments of physical and mathematical models of endoreversible three-reservoir NICP and its 3-D graphical illustration, as well as REP and COP analyses and optimizations.
{"title":"Endoreversible modeling, optimization and 3-D graphical illustration for a non-isothermal three-reservoir chemical pump based on Lewis criterion","authors":"Lingen Chen , Shuangshuang Shi , Yanlin Ge , Huijun Feng","doi":"10.1016/j.csite.2026.107729","DOIUrl":"10.1016/j.csite.2026.107729","url":null,"abstract":"<div><div>An endoreversible three-reservoir non-isothermal chemical-pump (NICP) cycle is modeled by equivalent combined-cycle method, taking it as combined-cycle of endoreversible two-reservoir NICP driven by endoreversible two-reservoir non-isothermal chemical-engine. Applying finite-time thermodynamics and considering heat-and-mass-transfer coupling effect following Lewis criterion, 3-D graphical illustration of NICP cycle is obtained, and expressions of rate of energy pumping (REP) and vector coefficients-of-performance (COPs) are derived. Effects of some fixed parameters on general relationship surface of REP and COPs are analyzed. At a fixed total mass-transfer coefficient, optimal distribution of mass-transfer coefficient is studied, and optimal relationship surface of three-reservoir NICP is obtained. Influence of working fluid physical properties on performance of three-reservoir NICP is analyzed and compared. 3-D graphical illustrations for three-reservoir NICP are conducive to understanding cycle processes. Results indicate that as both heat-transfer flow rate and mass-transfer flow rate increase, REP increases and vector COPs decrease. 3-D optimal relationship surface of REP and vector COPs is monotonically decreasing. Compared with three-reservoir heat-pump, REP of three-reservoir NICP increases by 114.16 %, while vector COP decreases by 4.43 %. Compared with three-reservoir isothermal-chemical-pump, REP of three-reservoir NICP increases by 896.91 %, and vector COP increases by 135.24 %. Mass-transfer process has detrimental effect on heat-transfer process. The physical properties of working fluid have no qualitative influence on performance of three-reservoir NICP, but only quantitative influence. General and optimal relationships of three-reservoir NICP include five special cases: those of two- and three-reservoir heat-pumps with Newton's heat-transfer law, those of two- and three-reservoir isothermal-chemical-pumps with diffusive mass-transfer law, and that of two-reservoir NICP following Lewis criterion. Main contributions herein are establishments of physical and mathematical models of endoreversible three-reservoir NICP and its 3-D graphical illustration, as well as REP and COP analyses and optimizations.</div></div>","PeriodicalId":9658,"journal":{"name":"Case Studies in Thermal Engineering","volume":"78 ","pages":"Article 107729"},"PeriodicalIF":6.4,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146033043","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Recent research in nanofluid application in refrigeration systems emphasise heat transfer enhancement and energy consumption reduction. There are limited experimental studies on how nanoparticles influence compressor operating pressures and discharge temperatures. This research addresses this gap by experimentally investigating the impact of 10 nm CuO nanoparticles on the performance of an R134a vapour compression refrigeration system. Nanoparticles were dispersed in Polyolester (POE) oil at mass concentrations of 0.025 %–0.30 %. Effects of nanoparticles on compressor suction and discharge pressures, pressure ratio, discharge temperature, refrigerating effect, compressor work, and coefficient of performance (COP) were studied. The results signified that CuO has minimal effect on compressor suction pressure while the discharge pressure decreased by up to 16.29 %, indicating reduced friction at the piston-cylinder interface. Compressor's discharge temperature was lowered by up to 16.54 %, which potentially reduces oil breakdown. Refrigerating effect improved by up to 8.58 % due to enhanced evaporator heat transfer and nucleation site formation. Compressor work reduced by up to 20.33 %, which is attributed to improved lubrication and reduced frictional losses. System COP reached an improvement of 35.89 % at 0.25 % mass concentration, demonstrating a substantial increase in energy performance. These experimental findings demonstrate the potential of CuO nanolubricant as an energy efficiency solution in refrigeration systems.
{"title":"Experimental analysis of an R134a refrigeration system using POE/CuO nanolubricant","authors":"Asasei Unarine Casey Ndanduleni, Teboho Ramathe, Zhongjie Huan","doi":"10.1016/j.csite.2026.107734","DOIUrl":"10.1016/j.csite.2026.107734","url":null,"abstract":"<div><div>Recent research in nanofluid application in refrigeration systems emphasise heat transfer enhancement and energy consumption reduction. There are limited experimental studies on how nanoparticles influence compressor operating pressures and discharge temperatures. This research addresses this gap by experimentally investigating the impact of 10 nm CuO nanoparticles on the performance of an R134a vapour compression refrigeration system. Nanoparticles were dispersed in Polyolester (POE) oil at mass concentrations of 0.025 %–0.30 %. Effects of nanoparticles on compressor suction and discharge pressures, pressure ratio, discharge temperature, refrigerating effect, compressor work, and coefficient of performance (COP) were studied. The results signified that CuO has minimal effect on compressor suction pressure while the discharge pressure decreased by up to 16.29 %, indicating reduced friction at the piston-cylinder interface. Compressor's discharge temperature was lowered by up to 16.54 %, which potentially reduces oil breakdown. Refrigerating effect improved by up to 8.58 % due to enhanced evaporator heat transfer and nucleation site formation. Compressor work reduced by up to 20.33 %, which is attributed to improved lubrication and reduced frictional losses. System COP reached an improvement of 35.89 % at 0.25 % mass concentration, demonstrating a substantial increase in energy performance. These experimental findings demonstrate the potential of CuO nanolubricant as an energy efficiency solution in refrigeration systems.</div></div>","PeriodicalId":9658,"journal":{"name":"Case Studies in Thermal Engineering","volume":"78 ","pages":"Article 107734"},"PeriodicalIF":6.4,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146048051","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In response to subgrade frost heave damage in cold regions, an active heating method that utilizes geothermal energy is proposed. By using ground source heat pump technology, a dedicated heat regulation system and a distributed heating scheme are designed for the subgrade. A full-scale subgrade test platform is built to test the heating performance and subgrade thermal regulatory mechanisms of this system in winter. The test results show that in the operation mode with a start: stop ratio of 2 h:1 h, the heat regulation system can reach heat supply temperatures of 17∼33 °C. Moreover, the operating performance under cold winter conditions is stable. The coefficient of performance of the thermal regulation system can exceed 5.8, but it decreases with increasing time. The heat diffusion process from the heat supply pipe to the subgrade exhibits spatial hysteresis. Within 4 d, heat can diffuse in the vertical direction throughout surface layer of the subgrade. Furthermore, the magnitude of the increase in temperature gradually decreases with increasing distance from the heat supply pipe or with increasing time. After 4 d of heating, heat diffuses in the longitudinal direction at a distance of 125 cm in the subgrade. The variation in the freezing depth of the subgrade is controlled by both the atmospheric environment and the thermal regulation system. After 16 d of heating, the freezing depth decreases from 74 cm to less than 17 cm.
{"title":"Thermal Regulation and Frost Control of Subgrade by a Ground Source Heat Pump System","authors":"Tianfei Hu, Rui Yang, Zuren Yue, Song Zhang, Yanqiu Shi, Taofan He, Zhifeng Ren","doi":"10.1016/j.csite.2026.107790","DOIUrl":"https://doi.org/10.1016/j.csite.2026.107790","url":null,"abstract":"In response to subgrade frost heave damage in cold regions, an active heating method that utilizes geothermal energy is proposed. By using ground source heat pump technology, a dedicated heat regulation system and a distributed heating scheme are designed for the subgrade. A full-scale subgrade test platform is built to test the heating performance and subgrade thermal regulatory mechanisms of this system in winter. The test results show that in the operation mode with a start: stop ratio of 2 h:1 h, the heat regulation system can reach heat supply temperatures of 17∼33 °C. Moreover, the operating performance under cold winter conditions is stable. The coefficient of performance of the thermal regulation system can exceed 5.8, but it decreases with increasing time. The heat diffusion process from the heat supply pipe to the subgrade exhibits spatial hysteresis. Within 4 d, heat can diffuse in the vertical direction throughout surface layer of the subgrade. Furthermore, the magnitude of the increase in temperature gradually decreases with increasing distance from the heat supply pipe or with increasing time. After 4 d of heating, heat diffuses in the longitudinal direction at a distance of 125 cm in the subgrade. The variation in the freezing depth of the subgrade is controlled by both the atmospheric environment and the thermal regulation system. After 16 d of heating, the freezing depth decreases from 74 cm to less than 17 cm.","PeriodicalId":9658,"journal":{"name":"Case Studies in Thermal Engineering","volume":"5 1","pages":""},"PeriodicalIF":6.8,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146098223","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-01DOI: 10.1016/j.csite.2026.107728
Yuan Gao , Qing Gao , Jianwei Lv
With the diversification and complexity of vehicle thermal management requirements, the integration and control of different subsystems for specific utilizations require effective architectures and methods. This paper proposes a hierarchical control architecture that defines the control logic for multi-system through framework design. Based on this, the study focuses on a multi-system integrated vehicle thermal management system including battery, air conditioner and vehicle refrigerator characterized by low refrigeration temperature and high integration complexity. Through the refrigeration regulation method based on the Variable Openings Valve (VOV) and proposed Compressor-Valve Synergistic Enhancement (CVSE) method, cooling assurance for multi-system is achieved while ensuring the thermal safety of the battery and the comfort of the cabin. Subsequently, by analyzing the operational mode and operational process, the study explored their impact on the temperature system control performance and energy efficiency, thus optimizing the operation of the CVSE method. Furthermore, implement the operation optimization, a multi-criteria fusion control strategy is designed for complex actual loaded operating condition, introducing vehicle speed, ambient conditions, and subsystems temperature as input parameters. The results indicated that compared to conventional strategy that does not utilize operation optimization, the proposed strategy achieved approximately 10.8 % improvement in COP while maintaining effective temperature control under harsh operating conditions, achieving a balance between temperature control effectiveness and energy economy.
{"title":"Study on refrigeration regulation and control optimization for multi-system integrated vehicle thermal management system","authors":"Yuan Gao , Qing Gao , Jianwei Lv","doi":"10.1016/j.csite.2026.107728","DOIUrl":"10.1016/j.csite.2026.107728","url":null,"abstract":"<div><div>With the diversification and complexity of vehicle thermal management requirements, the integration and control of different subsystems for specific utilizations require effective architectures and methods. This paper proposes a hierarchical control architecture that defines the control logic for multi-system through framework design. Based on this, the study focuses on a multi-system integrated vehicle thermal management system including battery, air conditioner and vehicle refrigerator characterized by low refrigeration temperature and high integration complexity. Through the refrigeration regulation method based on the Variable Openings Valve (VOV) and proposed Compressor-Valve Synergistic Enhancement (CVSE) method, cooling assurance for multi-system is achieved while ensuring the thermal safety of the battery and the comfort of the cabin. Subsequently, by analyzing the operational mode and operational process, the study explored their impact on the temperature system control performance and energy efficiency, thus optimizing the operation of the CVSE method. Furthermore, implement the operation optimization, a multi-criteria fusion control strategy is designed for complex actual loaded operating condition, introducing vehicle speed, ambient conditions, and subsystems temperature as input parameters. The results indicated that compared to conventional strategy that does not utilize operation optimization, the proposed strategy achieved approximately 10.8 % improvement in COP while maintaining effective temperature control under harsh operating conditions, achieving a balance between temperature control effectiveness and energy economy.</div></div>","PeriodicalId":9658,"journal":{"name":"Case Studies in Thermal Engineering","volume":"78 ","pages":"Article 107728"},"PeriodicalIF":6.4,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146033044","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-01DOI: 10.1016/j.csite.2026.107786
Yassine Bouazzi, Zakarya Ahmed, Ali Basem, As'ad Alizadeh, Mohamed Shaban, Abdellatif M. Sadeq, Walid Aich, Borhen Louhichi
In the present investigation, thermal and mixing efficiencies of the fuel jet behind the strut within combustor of scramjet engine have been extensively investigated. Combination of annular with/without internal air flow in two strut angles of 15° and 7.5 are analyzed via three-dimensional modelling of fuel jet released from single injector. Important flow features and vortex structure are evaluated to reveal the mixing nature of the proposed system. Computational fluid dynamic is used for the modelling of flow in combustor via solving RANS equations with SST turbulence model. The results reveal that the combination of a 7.5° strut angle with an internal air jet results in a 31% improvement over the baseline annular-only case at the same angle, achieving the highest mean mixing index of 0.495. Although the 15° strut with internal air jet produces the highest initial circulation strength (∼0.85), its mixing effect diminishes more rapidly downstream due to strong localized flow separation. In contrast, the 7.5° case with air assist maintains strong and consistent circulation (∼0.60 to 0.30) over a longer distance, leading to superior mixing uniformity. The internal air jet significantly enhances the breakup of the annular jet, introduces central vortices, and increases fuel-air interface area in all cases. These findings demonstrate that an inclined strut with integrated air-assisted annular injection, particularly at moderate angles, offers energy-efficient solution for improving fuel-air mixing in high-speed combustion applications.
{"title":"Fuel Mixing and thermal Enhancement Behind an Inclined Strut in a Supersonic Combustor via single Annular with Air-Assisted Injector","authors":"Yassine Bouazzi, Zakarya Ahmed, Ali Basem, As'ad Alizadeh, Mohamed Shaban, Abdellatif M. Sadeq, Walid Aich, Borhen Louhichi","doi":"10.1016/j.csite.2026.107786","DOIUrl":"https://doi.org/10.1016/j.csite.2026.107786","url":null,"abstract":"In the present investigation, thermal and mixing efficiencies of the fuel jet behind the strut within combustor of scramjet engine have been extensively investigated. Combination of annular with/without internal air flow in two strut angles of 15° and 7.5 are analyzed via three-dimensional modelling of fuel jet released from single injector. Important flow features and vortex structure are evaluated to reveal the mixing nature of the proposed system. Computational fluid dynamic is used for the modelling of flow in combustor via solving RANS equations with SST turbulence model. The results reveal that the combination of a 7.5° strut angle with an internal air jet results in a 31% improvement over the baseline annular-only case at the same angle, achieving the highest mean mixing index of 0.495. Although the 15° strut with internal air jet produces the highest initial circulation strength (∼0.85), its mixing effect diminishes more rapidly downstream due to strong localized flow separation. In contrast, the 7.5° case with air assist maintains strong and consistent circulation (∼0.60 to 0.30) over a longer distance, leading to superior mixing uniformity. The internal air jet significantly enhances the breakup of the annular jet, introduces central vortices, and increases fuel-air interface area in all cases. These findings demonstrate that an inclined strut with integrated air-assisted annular injection, particularly at moderate angles, offers energy-efficient solution for improving fuel-air mixing in high-speed combustion applications.","PeriodicalId":9658,"journal":{"name":"Case Studies in Thermal Engineering","volume":"55 1","pages":""},"PeriodicalIF":6.8,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146098226","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-01DOI: 10.1016/j.csite.2026.107714
Yingya Chen , Zelin Chen , Yongxiang Liang , Lei Li , Zhiwei Wang
In low-latitude islands characterized by extreme humidity and heat, effective dehumidification and cooling are essential for indoor environmental comfort. However, energy supply challenges persist due to geographical isolation, necessitating energy-efficient systems with stable operation. This study proposes three dehumidification/cooling systems tailored to such climates, utilizing dual solid desiccant wheels. Comparative analysis revealed the solar-powered two-stage desiccant wheel coupled with mechanical refrigeration (SDW-VCR) system as optimal. After optimization, peak thermodynamic performance (COPth = 1.32) was achieved at a 30 % return air ratio and 85 °C regeneration temperature. The system delivers 57.2 kW total cooling capacity, with the refrigeration unit handling 11.6 kW (20.3 %) of sensible heat. Notably, the condenser inlet air temperature approximates ambient conditions due to high evaporation temperatures, yielding a refrigeration COP of 4.85. Regeneration heating demand was reduced by preheating air through condensation heat recovery. These findings establish a reference framework for sustainable thermal environment management in high-humidity tropical islands.
{"title":"Performance analysis and optimization of two-stage desiccant wheel cooling systems in low-latitude island with hot and humid climate","authors":"Yingya Chen , Zelin Chen , Yongxiang Liang , Lei Li , Zhiwei Wang","doi":"10.1016/j.csite.2026.107714","DOIUrl":"10.1016/j.csite.2026.107714","url":null,"abstract":"<div><div>In low-latitude islands characterized by extreme humidity and heat, effective dehumidification and cooling are essential for indoor environmental comfort. However, energy supply challenges persist due to geographical isolation, necessitating energy-efficient systems with stable operation. This study proposes three dehumidification/cooling systems tailored to such climates, utilizing dual solid desiccant wheels. Comparative analysis revealed the solar-powered two-stage desiccant wheel coupled with mechanical refrigeration (SDW-VCR) system as optimal. After optimization, peak thermodynamic performance (<em>COP</em><sub><em>th</em></sub> = 1.32) was achieved at a 30 % return air ratio and 85 °C regeneration temperature. The system delivers 57.2 kW total cooling capacity, with the refrigeration unit handling 11.6 kW (20.3 %) of sensible heat. Notably, the condenser inlet air temperature approximates ambient conditions due to high evaporation temperatures, yielding a refrigeration <em>COP</em> of 4.85. Regeneration heating demand was reduced by preheating air through condensation heat recovery. These findings establish a reference framework for sustainable thermal environment management in high-humidity tropical islands.</div></div>","PeriodicalId":9658,"journal":{"name":"Case Studies in Thermal Engineering","volume":"78 ","pages":"Article 107714"},"PeriodicalIF":6.4,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146014333","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-31DOI: 10.1016/j.csite.2026.107781
Huu Linh Nguyen, Dongkeun Song, Sy Vong Le, Yoora Choi, Sangseok Yu
{"title":"Analysis of cooling system topology of dual stack proton exchange membrane fuel cell system for heavy-duty truck","authors":"Huu Linh Nguyen, Dongkeun Song, Sy Vong Le, Yoora Choi, Sangseok Yu","doi":"10.1016/j.csite.2026.107781","DOIUrl":"https://doi.org/10.1016/j.csite.2026.107781","url":null,"abstract":"","PeriodicalId":9658,"journal":{"name":"Case Studies in Thermal Engineering","volume":"42 1","pages":""},"PeriodicalIF":6.8,"publicationDate":"2026-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146095607","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-31DOI: 10.1016/j.csite.2026.107752
Umar Farooq, Yaqiao Han, Tao Liu, Hinza Sultan, Ali Alshamrani
{"title":"Thermal Management of Rocket Nozzles Using MHD Copper-Ionic Liquid Nanofluid in Jeffery-Hamel Flow","authors":"Umar Farooq, Yaqiao Han, Tao Liu, Hinza Sultan, Ali Alshamrani","doi":"10.1016/j.csite.2026.107752","DOIUrl":"https://doi.org/10.1016/j.csite.2026.107752","url":null,"abstract":"","PeriodicalId":9658,"journal":{"name":"Case Studies in Thermal Engineering","volume":"104 1","pages":""},"PeriodicalIF":6.8,"publicationDate":"2026-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146089240","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}