Applied Thermal Engineering最新文献_第3页

Evaluation of the energy system variable operating conditions under the lunar environment

IF 6.1 2区工程技术 Q2 ENERGY & FUELS

Applied Thermal Engineering

Pub Date : 2025-02-27 DOI: 10.1016/j.applthermaleng.2025.126095

Zekuan Liu , Lili Wen , Pengyue Liu , Teng Fei , Jiang Qin

The periodic fluctuations of the heat and cold sources on the moon cause changes in the operating efficiency of the equipment within the energy system. Thus, the thermodynamic performance of the energy system cannot be evaluated through research under the design point conditions. In order to accurately evaluate the power generation characteristics, this paper establishes off-design operating conditions model of the closed Brayton cycle (CBC)-organic Rankine cycle (ORC) system considered lunar surface temperature and radiation intensity. It is found that 10,000 rpm is suitable for the lunar daytime, and the average power generation can reach 63.99 kW under the constant speed mode of the compressor and turbine. Under the constant power output mode, the average power generation is 56.43 kW. The constant speed output mode is more suitable for the lunar daytime. During the lunar night, due to the significant decrease in the lunar surface temperature, the power generation of ORC is enhanced. Under the constant speed output mode, when CBC is stopped on the 19th earth day, the average power generation can reach a maximum of 178.81 kW. Under the constant power output mode, the constant output power range of CBC-ORC is 42.25 kW to 184.56 kW. Considering the continuous operation of life support equipment during the lunar night, it is more appropriate to select the constant power output mode. This study takes into account the operating characteristics of the lunar energy system throughout the lunar day, fully considers the changes in the heat and cold sources at the lunar base, and provides certain guidance for the practical operation of the energy system.

{"title":"Evaluation of the energy system variable operating conditions under the lunar environment","authors":"Zekuan Liu , Lili Wen , Pengyue Liu , Teng Fei , Jiang Qin","doi":"10.1016/j.applthermaleng.2025.126095","DOIUrl":"10.1016/j.applthermaleng.2025.126095","url":null,"abstract":"<div><div>The periodic fluctuations of the heat and cold sources on the moon cause changes in the operating efficiency of the equipment within the energy system. Thus, the thermodynamic performance of the energy system cannot be evaluated through research under the design point conditions. In order to accurately evaluate the power generation characteristics, this paper establishes off-design operating conditions model of the closed Brayton cycle (CBC)-organic Rankine cycle (ORC) system considered lunar surface temperature and radiation intensity. It is found that 10,000 rpm is suitable for the lunar daytime, and the average power generation can reach 63.99 kW under the constant speed mode of the compressor and turbine. Under the constant power output mode, the average power generation is 56.43 kW. The constant speed output mode is more suitable for the lunar daytime. During the lunar night, due to the significant decrease in the lunar surface temperature, the power generation of ORC is enhanced. Under the constant speed output mode, when CBC is stopped on the 19th earth day, the average power generation can reach a maximum of 178.81 kW. Under the constant power output mode, the constant output power range of CBC-ORC is 42.25 kW to 184.56 kW. Considering the continuous operation of life support equipment during the lunar night, it is more appropriate to select the constant power output mode. This study takes into account the operating characteristics of the lunar energy system throughout the lunar day, fully considers the changes in the heat and cold sources at the lunar base, and provides certain guidance for the practical operation of the energy system.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"269 ","pages":"Article 126095"},"PeriodicalIF":6.1,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143552909","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}

引用次数: 0

Thermoelectric cooling systems for eVTOL batteries operating on hot days

IF 6.1 2区工程技术 Q2 ENERGY & FUELS

Applied Thermal Engineering

Pub Date : 2025-02-27 DOI: 10.1016/j.applthermaleng.2025.125999

Chunrong Zhao , Seeta Ratnam Gunti , Hagen Kellermann , Andrew Gong , Simon Coburn , Andrew Moore , Dries Verstraete

Fast advancements in high-energy and -power density batteries, have recently enabled fully battery-powered advanced air mobility (AAM) aircraft development. Given the thermal-sensitive characteristics of lithium-ion batteries (LiB), those electric aircraft require a lightweight and highly-efficient battery thermal management system (BTMS) to dissipate waste heat, particularly for power-hungry flight phases or at high ambient temperature. To date, the relevant investigations, specifically for electric aircraft, are missing; therefore, as the first attempt, we introduce a thermoelectric heat exchanger into a previously developed liquid-cooling-based BTMS for a tilt-wing electric vertical take-off and landing (eVTOL) aircraft to mitigate aforementioned aerothermal concerns. We first compare a BTMS with and without the thermoelectric cooler (TEC) based on a hover-free flight mission to demonstrate its effectiveness and weight-and-power penalty. We then simulate and compare BTMS performance for four different hover durations (1, 3, 5, and 7 min). Our results show that, as the hover duration increases, the TEC-based BTMS works well for ambient temperature up to 45 °C at the expense of a reduced number of flights and additional weight. On the contrary, a TEC-free BTMS can only manage battery temperatures and health for ambient temperatures below 20 °C.

{"title":"Thermoelectric cooling systems for eVTOL batteries operating on hot days","authors":"Chunrong Zhao , Seeta Ratnam Gunti , Hagen Kellermann , Andrew Gong , Simon Coburn , Andrew Moore , Dries Verstraete","doi":"10.1016/j.applthermaleng.2025.125999","DOIUrl":"10.1016/j.applthermaleng.2025.125999","url":null,"abstract":"<div><div>Fast advancements in high-energy and -power density batteries, have recently enabled fully battery-powered advanced air mobility (AAM) aircraft development. Given the thermal-sensitive characteristics of lithium-ion batteries (LiB), those electric aircraft require a lightweight and highly-efficient battery thermal management system (BTMS) to dissipate waste heat, particularly for power-hungry flight phases or at high ambient temperature. To date, the relevant investigations, specifically for electric aircraft, are missing; therefore, as the first attempt, we introduce a thermoelectric heat exchanger into a previously developed liquid-cooling-based BTMS for a tilt-wing electric vertical take-off and landing (eVTOL) aircraft to mitigate aforementioned aerothermal concerns. We first compare a BTMS with and without the thermoelectric cooler (TEC) based on a hover-free flight mission to demonstrate its effectiveness and weight-and-power penalty. We then simulate and compare BTMS performance for four different hover durations (1, 3, 5, and 7 min). Our results show that, as the hover duration increases, the TEC-based BTMS works well for ambient temperature up to 45 °C at the expense of a reduced number of flights and additional weight. On the contrary, a TEC-free BTMS can only manage battery temperatures and health for ambient temperatures below 20 °C.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"269 ","pages":"Article 125999"},"PeriodicalIF":6.1,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143511273","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Generalized engineering equations of heat-transfer performance for twisted heat exchanger with slurries from biogas plants by using Machine learning driven by mechanism and data

IF 6.1 2区工程技术 Q2 ENERGY & FUELS

Applied Thermal Engineering

Pub Date : 2025-02-26 DOI: 10.1016/j.applthermaleng.2025.126046

Yan Liu , Shanshan Wang , Liwen Mu , Mikael Risberg , Urban Jansson , Jiahua Zhu , Xiaohua Lu , Xiaoyan Ji , Jingjing Chen

The development of generalized engineering equations of the heat-transfer performance in enhanced geometries for different slurries is crucial for practical applications but difficult owing to the complex rheological properties. In the present study, a method of computational-fluid-dynamics-data-driven machine learning was proposed to establish generalized engineering equations in a novel twisted geometry for multiple slurries with a single substrate. The applicability of the equations for a mixed slurry was determined by comparing the predictions and computational fluid dynamics simulations. It was found that the established equations considering the key parameter–effective shear rate show a high accuracy with an average relative deviation of 17.3 % for single-substrate slurries with the scope of viscosities and flow behavior index ranging from 0.057-93.96 Pa·s and 0.257–0.579, respectively. Moreover, the generalized engineering equations show an average relative deviation of 12.4 % in prediction for the mixed slurry possessing the temperature- and shearing-sensitive rheological behavior. The generalized engineering equations quantitatively reveal the positive effect of non-Newtonian behavior on the heat-transfer enhancement of THT for different slurries. Based on this mechanism, a mixed slurry is recommend with energy-conservation of 60.00 GW·h/year for a full-scale biogas plant.

{"title":"Generalized engineering equations of heat-transfer performance for twisted heat exchanger with slurries from biogas plants by using Machine learning driven by mechanism and data","authors":"Yan Liu , Shanshan Wang , Liwen Mu , Mikael Risberg , Urban Jansson , Jiahua Zhu , Xiaohua Lu , Xiaoyan Ji , Jingjing Chen","doi":"10.1016/j.applthermaleng.2025.126046","DOIUrl":"10.1016/j.applthermaleng.2025.126046","url":null,"abstract":"<div><div>The development of generalized engineering equations of the heat-transfer performance in enhanced geometries for different slurries is crucial for practical applications but difficult owing to the complex rheological properties. In the present study, a method of computational-fluid-dynamics-data-driven machine learning was proposed to establish generalized engineering equations in a novel twisted geometry for multiple slurries with a single substrate. The applicability of the equations for a mixed slurry was determined by comparing the predictions and computational fluid dynamics simulations. It was found that the established equations considering the key parameter–effective shear rate show a high accuracy with an average relative deviation of 17.3 % for single-substrate slurries with the scope of viscosities and flow behavior index ranging from 0.057-93.96 Pa·s and 0.257–0.579, respectively. Moreover, the generalized engineering equations show an average relative deviation of 12.4 % in prediction for the mixed slurry possessing the temperature- and shearing-sensitive rheological behavior. The generalized engineering equations quantitatively reveal the positive effect of non-Newtonian behavior on the heat-transfer enhancement of THT for different slurries. Based on this mechanism, a mixed slurry is recommend with energy-conservation of 60.00 GW·h/year for a full-scale biogas plant.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"269 ","pages":"Article 126046"},"PeriodicalIF":6.1,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143529397","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}

引用次数: 0

Modeling and optimization of an endoreversible non-isothermal chemical pump cycle via Onsager equations

IF 6.1 2区工程技术 Q2 ENERGY & FUELS

Applied Thermal Engineering

Pub Date : 2025-02-26 DOI: 10.1016/j.applthermaleng.2025.126089

Shuangshuang Shi, Lingen Chen, Yanlin Ge, Huijun Feng

Assuming that the heat-and-mass-transfer process obeys the Onsager equations in linear irreversible thermodynamics, a model for an endoreversible non-isothermal-chemical-pump cycle is built, and its performance is optimized. The analytical results of rate of energy-pumping and vector coefficient of performances (See Eq. (20) in this paper for its definition) are obtained. Effects of cycle design parameters on the cycle optimal performances are analyzed. The findings show that: With the increase of energy flux, the rate of energy-pumping increases, and vector coefficient of performances decrease. With the increase of mass-transfer flux, the rate of energy-pumping is unchanged. The surfaces of rate of energy-pumping versus vector coefficient of performances are monotonically decreasing ones, and with increase of cross-phenomenological coefficient of heat-and-mass-transfer, the vector coefficient of performances increase. Research results involve two special cases: the optimal performance for an endoreversible Carnot heat-pump cycle with linear phenomenological heat-transfer law and the optimal performance for an endoreversible isothermal chemical pump with linear mass-transfer law.

{"title":"Modeling and optimization of an endoreversible non-isothermal chemical pump cycle via Onsager equations","authors":"Shuangshuang Shi, Lingen Chen, Yanlin Ge, Huijun Feng","doi":"10.1016/j.applthermaleng.2025.126089","DOIUrl":"10.1016/j.applthermaleng.2025.126089","url":null,"abstract":"<div><div>Assuming that the heat-and-mass-transfer process obeys the Onsager equations in linear irreversible thermodynamics, a model for an endoreversible non-isothermal-chemical-pump cycle is built, and its performance is optimized. The analytical results of rate of energy-pumping and vector coefficient of performances (See Eq. <span><span>(20)</span></span> in this paper for its definition) are obtained. Effects of cycle design parameters on the cycle optimal performances are analyzed. The findings show that: With the increase of energy flux, the rate of energy-pumping increases, and vector coefficient of performances decrease. With the increase of mass-transfer flux, the rate of energy-pumping is unchanged. The surfaces of rate of energy-pumping versus vector coefficient of performances are monotonically decreasing ones, and with increase of cross-phenomenological coefficient of heat-and-mass-transfer, the vector coefficient of performances increase. Research results involve two special cases: the optimal performance for an endoreversible Carnot heat-pump cycle with linear phenomenological heat-transfer law and the optimal performance for an endoreversible isothermal chemical pump with linear mass-transfer law.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"269 ","pages":"Article 126089"},"PeriodicalIF":6.1,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143529435","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}

引用次数: 0

Characteristics analysis for turbine film cooling under rotating detonation combustion

IF 6.1 2区工程技术 Q2 ENERGY & FUELS

Applied Thermal Engineering

Pub Date : 2025-02-26 DOI: 10.1016/j.applthermaleng.2025.126054

Yingchen Liu , Ting Zhao , Changlong Wen , Feng Guo , Jianfeng Zhu

The integration of rotating detonation combustors into turbine engines has garnered significant attention due to their potential to enhance engine performance. However, the high-frequency pulsations of exhaust flow from rotating detonation combustors create significant challenges for turbine design. The lack of comprehensive analysis of turbine film cooling under rotating detonation inflow conditions has hindered advancements in the cooling strategies for turbine blades. This study aims to fill this gap by conducting numerical simulations to analyze the aerothermal loads and film cooling characteristics of turbine blades under rotating detonation inflow. The results revealed that detonation inflow induces highly uneven spatial and temporal pressure distribution, increasing both pulsation intensity and aerothermal loads on turbine blades. Under these conditions, conventional film cooling experiences periodic cooling air disruption and hot gas backflow, leading to low cooling efficiency. Specifically, during clockwise and counterclockwise detonation wave propagation, the minimum duration of cooling air outflow accounted for only 26 % and 22 % of the total period, with corresponding average cooling efficiencies of 0.53 and 0.46, respectively. To mitigate these limitations, a secondary pressurization strategy was proposed. By increasing the cooling air pressure by 43 %, the cooling performance improved significantly, achieving average cooling efficiencies of 0.77 and 0.79 for clockwise and counterclockwise propagation, respectively.

{"title":"Characteristics analysis for turbine film cooling under rotating detonation combustion","authors":"Yingchen Liu , Ting Zhao , Changlong Wen , Feng Guo , Jianfeng Zhu","doi":"10.1016/j.applthermaleng.2025.126054","DOIUrl":"10.1016/j.applthermaleng.2025.126054","url":null,"abstract":"<div><div>The integration of rotating detonation combustors into turbine engines has garnered significant attention due to their potential to enhance engine performance. However, the high-frequency pulsations of exhaust flow from rotating detonation combustors create significant challenges for turbine design. The lack of comprehensive analysis of turbine film cooling under rotating detonation inflow conditions has hindered advancements in the cooling strategies for turbine blades. This study aims to fill this gap by conducting numerical simulations to analyze the aerothermal loads and film cooling characteristics of turbine blades under rotating detonation inflow. The results revealed that detonation inflow induces highly uneven spatial and temporal pressure distribution, increasing both pulsation intensity and aerothermal loads on turbine blades. Under these conditions, conventional film cooling experiences periodic cooling air disruption and hot gas backflow, leading to low cooling efficiency. Specifically, during clockwise and counterclockwise detonation wave propagation, the minimum duration of cooling air outflow accounted for only 26 % and 22 % of the total period, with corresponding average cooling efficiencies of 0.53 and 0.46, respectively. To mitigate these limitations, a secondary pressurization strategy was proposed. By increasing the cooling air pressure by 43 %, the cooling performance improved significantly, achieving average cooling efficiencies of 0.77 and 0.79 for clockwise and counterclockwise propagation, respectively.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"269 ","pages":"Article 126054"},"PeriodicalIF":6.1,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143552449","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}

引用次数: 0

Optimizing a ternary hybrid ferrofluid slip flow with magnetic dipole and viscous dissipation by Response Surface Methodology (RSM)

IF 6.1 2区工程技术 Q2 ENERGY & FUELS

Applied Thermal Engineering

Pub Date : 2025-02-26 DOI: 10.1016/j.applthermaleng.2025.126087

Shahirah Abu Bakar , Ioan Pop , Lit Ken Tan , Norihan Md Arifin

In electromagnetism, a magnetic dipole is a tiny loop of electric current or a pair of magnetic poles. As the loop size decreases to zero while maintaining a constant magnetic moment, it forms a magnetic dipole. Composed by the magnetic particles, ferromagnetic fluids align with magnetic fields and when a magnetic dipole interacts with such fluids, the particles magnetize the fluid and influence the dipole’s field. Hence, this study investigates the magnetic dipole and velocity slip on ternary hybrid ferrofluid flow past a shrinking surface. The model considers three magnetic nanoparticles – iron oxide (Fe₃O₄), cobalt ferrite (CoFe₂O₄), and copper (Cu) – dispersed in a base fluid. The similarity transformation technique is applied to derive mathematical models, which were solved numerically using bvp4c program in MATLAB. The analysis reveals that ferrohydrodynamic interaction reduces the skin friction coefficient and heat transfer rate but enhances velocity and temperature profiles. Additionally, the ternary hybrid ferrofluid is also shown to outperform both conventional ferrofluid and hybrid ferrofluid in fluid flow characteristics. Response Surface Methodology (RSM) is employed to identify the optimal combination of parameters, suggesting that the highest ferrohydrodynamic parameter and viscous dissipation, along with minimal Cu-nanoparticle concentration, maximize the heat transfer rate. Contour and surface plots illustrate these optimal conditions. This study highlights an innovative application of ternary ferrofluid with a magnetic dipole and employs RSM to optimize parameters for enhanced heat transfer performance, addressing a gap in existing literature and providing the way for further advancements in this field.

{"title":"Optimizing a ternary hybrid ferrofluid slip flow with magnetic dipole and viscous dissipation by Response Surface Methodology (RSM)","authors":"Shahirah Abu Bakar , Ioan Pop , Lit Ken Tan , Norihan Md Arifin","doi":"10.1016/j.applthermaleng.2025.126087","DOIUrl":"10.1016/j.applthermaleng.2025.126087","url":null,"abstract":"<div><div>In electromagnetism, a magnetic dipole is a tiny loop of electric current or a pair of magnetic poles. As the loop size decreases to zero while maintaining a constant magnetic moment, it forms a magnetic dipole. Composed by the magnetic particles, ferromagnetic fluids align with magnetic fields and when a magnetic dipole interacts with such fluids, the particles magnetize the fluid and influence the dipole’s field. Hence, this study investigates the magnetic dipole and velocity slip on ternary hybrid ferrofluid flow past a shrinking surface. The model considers three magnetic nanoparticles – iron oxide (Fe<sub>3</sub>O<sub>4</sub>), cobalt ferrite (CoFe<sub>2</sub>O<sub>4</sub>), and copper (Cu) – dispersed in a base fluid. The similarity transformation technique is applied to derive mathematical models, which were solved numerically using bvp4c program in MATLAB. The analysis reveals that ferrohydrodynamic interaction reduces the skin friction coefficient and heat transfer rate but enhances velocity and temperature profiles. Additionally, the ternary hybrid ferrofluid is also shown to outperform both conventional ferrofluid and hybrid ferrofluid in fluid flow characteristics. Response Surface Methodology (RSM) is employed to identify the optimal combination of parameters, suggesting that the highest ferrohydrodynamic parameter and viscous dissipation, along with minimal Cu-nanoparticle concentration, maximize the heat transfer rate. Contour and surface plots illustrate these optimal conditions. This study highlights an innovative application of ternary ferrofluid with a magnetic dipole and employs RSM to optimize parameters for enhanced heat transfer performance, addressing a gap in existing literature and providing the way for further advancements in this field.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"269 ","pages":"Article 126087"},"PeriodicalIF":6.1,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143511276","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}

引用次数: 0

Experimental study on heat transfer performance of silicon-based micro heat pipes with cylinder arrays

IF 6.1 2区工程技术 Q2 ENERGY & FUELS

Applied Thermal Engineering

Pub Date : 2025-02-26 DOI: 10.1016/j.applthermaleng.2025.126086

Xu Cheng , Wei Gao , Chaowei Chen , Xinyu Wang , Man Wang , Gongming Xin

The continuous miniaturization of high-performance integrated circuits appeals to efficient thermal management to maintain the stability and performance of chips. Micro heat pipes (MHPs) have been extensively studied for their superior thermal conductivity and compact size, while it still needs to be optimized to deal with the increase of heat flux of chips. This study designs silicon-based MHPs with micron-sized cylinder arrays at various channel positions to investigate their effects on heat transfer efficiency. Visual experiments assess the influence of cylinder arrangement, liquid filling rate, and applied power. The results show that MHPs with cylinder arrays significantly outperform traditional straight-channel MHPs, which has 68 % promotion in the thermal conductivity with maximum value of 874 W/(m·K). This improvement is attributed to the enhanced evaporation area and more efficient vapor flow within the heating section. Additionally, the high liquid filling rate of MHP exhibit superior heat transfer performance at high power level. 30 % liquid filling rate can be identified as optimal for balancing liquid–vapor dynamics. The equivalent thermal conductivity increases with the increase of power due to the intensity of gas–liquid circulation in the micro heat pipes. The placement and design of cylinder arrays have significantly impact on the overall thermal performance of the micro heat pipes. The findings of this study provide critical insights for the design and optimization of micro heat pipes for high-performance electronic devices.

{"title":"Experimental study on heat transfer performance of silicon-based micro heat pipes with cylinder arrays","authors":"Xu Cheng , Wei Gao , Chaowei Chen , Xinyu Wang , Man Wang , Gongming Xin","doi":"10.1016/j.applthermaleng.2025.126086","DOIUrl":"10.1016/j.applthermaleng.2025.126086","url":null,"abstract":"<div><div>The continuous miniaturization of high-performance integrated circuits appeals to efficient thermal management to maintain the stability and performance of chips. Micro heat pipes (MHPs) have been extensively studied for their superior thermal conductivity and compact size, while it still needs to be optimized to deal with the increase of heat flux of chips. This study designs silicon-based MHPs with micron-sized cylinder arrays at various channel positions to investigate their effects on heat transfer efficiency. Visual experiments assess the influence of cylinder arrangement, liquid filling rate, and applied power. The results show that MHPs with cylinder arrays significantly outperform traditional straight-channel MHPs, which has 68 % promotion in the thermal conductivity with maximum value of 874 W/(m·K). This improvement is attributed to the enhanced evaporation area and more efficient vapor flow within the heating section. Additionally, the high liquid filling rate of MHP exhibit superior heat transfer performance at high power level. 30 % liquid filling rate can be identified as optimal for balancing liquid–vapor dynamics. The equivalent thermal conductivity increases with the increase of power due to the intensity of gas–liquid circulation in the micro heat pipes. The placement and design of cylinder arrays have significantly impact on the overall thermal performance of the micro heat pipes. The findings of this study provide critical insights for the design and optimization of micro heat pipes for high-performance electronic devices.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"269 ","pages":"Article 126086"},"PeriodicalIF":6.1,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143529396","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}

引用次数: 0

Leveraging AI and geothermal cogeneration to boost energy efficiency in a multipurpose zero energy building

IF 6.1 2区工程技术 Q2 ENERGY & FUELS

Applied Thermal Engineering

Pub Date : 2025-02-26 DOI: 10.1016/j.applthermaleng.2025.125981

Saleh Mobayen , Ehsanolah Assareh , Mohammad Jafari , Tahereh pirhoushyaran , Le Cao Nhien , Mohammad Aasareh , Pouria Yavari , Moonyong Lee

Recent studies have targeted the emission of less CO₂ alongside saving more energy. To achieve part of this purpose, zero energy buildings (ZEBs) are introduced, replacing fossil fuels with renewable energies. This study focuses on a proposed cogeneration geothermal system, comprising two Rankine cycle units and an absorption chiller, designed to fulfill the clean energy requirements of a 5-story ZEB in Birmingham, England. Using BEopt software, the simulation, and optimization of the complex was performed. The net energy consumption of the building was calculated in one year. The energy assessment revealed the building’s electricity consumption at 2594.48 MWh, heating demand at 3157.63 MWh, and cooling requirement at 75.56 MWh annually. Using EES software, the complex’s energy supply system, was analyzed. Exergy efficiency (EE), and cost rate (CR), the outputs of EES, ought to be optimized via a combination of ANN and NSGA-II (Non-dominated Sorting Genetic Algorithm II). The optimization results showed that in the most optimal operating mode, an EE of 69.11 % and a CR of 23.1 $/h can be reached. Evaluating the cogeneration system’s performance in Birmingham demonstrated its capability to generate 6884.61 MWh of electricity, 27841.66 MWh of heating, and 2462.53 MWh of cooling per year using geothermal energy. Comparing the building’s energy consumption with the system’s production highlighted significant savings: 4290.28 MWh of electricity, 24682.71 MWh of heating, and 2385.01 MWh of cooling annually while meeting the complex’s energy needs yearly.

{"title":"Leveraging AI and geothermal cogeneration to boost energy efficiency in a multipurpose zero energy building","authors":"Saleh Mobayen , Ehsanolah Assareh , Mohammad Jafari , Tahereh pirhoushyaran , Le Cao Nhien , Mohammad Aasareh , Pouria Yavari , Moonyong Lee","doi":"10.1016/j.applthermaleng.2025.125981","DOIUrl":"10.1016/j.applthermaleng.2025.125981","url":null,"abstract":"<div><div>Recent studies have targeted the emission of less CO<sub>2</sub> alongside saving more energy. To achieve part of this purpose, zero energy buildings (ZEBs) are introduced, replacing fossil fuels with renewable energies. This study focuses on a proposed cogeneration geothermal system, comprising two Rankine cycle units and an absorption chiller, designed to fulfill the clean energy requirements of a 5-story ZEB in Birmingham, England. Using BEopt software, the simulation, and optimization of the complex was performed. The net energy consumption of the building was calculated in one year. The energy assessment revealed the building’s electricity consumption at 2594.48 MWh, heating demand at 3157.63 MWh, and cooling requirement at 75.56 MWh annually. Using EES software, the complex’s energy supply system, was analyzed. Exergy efficiency (EE), and cost rate (CR), the outputs of EES, ought to be optimized via a combination of ANN and NSGA-II (Non-dominated Sorting Genetic Algorithm II). The optimization results showed that in the most optimal operating mode, an EE of 69.11 % and a CR of 23.1 $/h can be reached. Evaluating the cogeneration system’s performance in Birmingham demonstrated its capability to generate 6884.61 MWh of electricity, 27841.66 MWh of heating, and 2462.53 MWh of cooling per year using geothermal energy. Comparing the building’s energy consumption with the system’s production highlighted significant savings: 4290.28 MWh of electricity, 24682.71 MWh of heating, and 2385.01 MWh of cooling annually while meeting the complex’s energy needs yearly.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"269 ","pages":"Article 125981"},"PeriodicalIF":6.1,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143552875","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}

引用次数: 0

Heat transfer performance of a micro heat pipe array filled with copper foam

IF 6.1 2区工程技术 Q2 ENERGY & FUELS

Applied Thermal Engineering

Pub Date : 2025-02-25 DOI: 10.1016/j.applthermaleng.2025.126068

Lincheng Wang , Zhenhua Quan , Hongxia Xu , Hang Guo , Yaohua Zhao

To investigate the method to enhance the heat transfer performance of a micro heat pipe array, two types of copper foam with different pore-diameters and porosities were added inside the micro heat pipe array with rectangular micro-fins, respectively, to form a composite wick inside the micro heat pipe array. An experimental investigation was conducted to explore the relationship between the thermal resistance and heating power of the copper foam micro heat pipe array across various ambient temperatures. It was found that the addition of copper foam obviously improves the capillary force of the wick and reduce the thermal resistance from 0.635 K/W to 0.445 K/W and 0.394 K/W, which were 29.9 % and 38.0 %, respectively, at the heating power of about 18 W. The impact of the ambient temperature on the thermal resistance of the copper foam micro heat pipe array depends on the geometry of the copper foam. The study provides a data base for the enhanced heat transfer mechanism of a micro heat pipe array by composite wicks, and acts as a reference for methods to improve the performance of micro heat pipe arrays.

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引用次数: 0

Direct integration of supercritical carbon dioxide-based concentrated solar power systems and gas power cycles: Advances and outlook

IF 6.1 2区工程技术 Q2 ENERGY & FUELS

Applied Thermal Engineering

Pub Date : 2025-02-25 DOI: 10.1016/j.applthermaleng.2025.126064

Mahmoud M. Abdelghafar, Muhammed A. Hassan, Hatem Kayed

The integration of concentrated solar power systems with supercritical carbon dioxide (sCO₂) power cycles offers a promising pathway for sustainable electricity generation. Despite the growing interest, no comprehensive review has yet been dedicated to this emerging technology, which is still in its early stages of development and requires a systematic evaluation of its technical, economic, and operational challenges to unlock its full potential for sustainable electricity generation. This systematic review examines the current global status of directly integrated sCO₂ power cycles with concentrated solar power, a strategy that eliminates intermediate heat exchangers, reducing thermal losses and enabling higher turbine inlet temperatures (>700 °C). This approach enhances overall thermal efficiency (up to 40 %) and Brayton cycle efficiency (up to 60 %), while lowering plant costs by 3.3–4.7 %. However, achieving these efficiencies requires operating at pressures above 20 MPa, necessitating advanced designs for the solar field, heat exchangers, piping, and storage systems, which increase capital costs. Effective control strategies are also essential for maintaining performance under off-design conditions, fluctuating ambient temperatures, and varying solar irradiance. Thermal energy storage and auxiliary heaters play a crucial role in stabilizing power supply, with thermal storage reducing the levelized cost of energy by 10.4 % compared to auxiliary heaters, though the latter has a lower initial cost. This review evaluates receiver designs, power block configurations, and key technological challenges in direct sCO₂ integration. It highlights research gaps, including the limited study of real-world conditions (e.g., non-uniform irradiance), insufficient exploration of hybrid systems integrating geothermal or biomass heat sources (potentially reducing fossil fuel use by up to 38 %), and underutilization of CO₂ mixtures, which could expand Brayton cycle applications and improve thermal efficiency by up to 7 %. Finally, the review outlines future research directions to advance high-efficiency, low-cost CSP technologies, emphasizing the need for innovative materials, optimized control strategies, and hybrid integration to enhance system viability and scalability.

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引用次数: 0