Energy Conversion and Management最新文献

{"title":"Data-driven multi-objective optimization of surfactant-modified nano-organic working fluids for enhanced heat transfer in ORC phase-change processes","authors":"Yong-qiang Feng ,&nbsp;Zhi-xin Wang ,&nbsp;Kang-jing Xu ,&nbsp;Zhen-zhen Yang ,&nbsp;Mu-ye Liu ,&nbsp;Hua-jian Wu ,&nbsp;Yong-zhen Wang ,&nbsp;Zhi-xia He","doi":"10.1016/j.enconman.2025.119815","DOIUrl":"10.1016/j.enconman.2025.119815","url":null,"abstract":"<div><div>Surfactant-mediated interfacial interactions in nano-organic working fluids effectively modulate colloidal thermophysical properties, leading to marked improvements in suspension stability and heat transfer performance within organic Rankine cycle (ORC) systems. Based on experimental data for nano-organic working fluids with three surfactants (CTAB, SDBS, and Span80), this study employs machine learning framework for prediction and optimization of the heat transfer and flow characteristics in ORC phase-change processes. A back propagation artificial neural network (BPANN) model is developed using 350 sets of transient steady-state experimental data, with the first 280 sets as training samples and the last 70 sets for testing, configured with 13 hidden nodes, a learning rate of 0.4, and the trainlm training function. The effects of six key operation parameters on evaporation and condensation heat transfer coefficients are investigated. A further bi-objective optimization considering maximum heat transfer coefficient and minimum pressure drop is addressed, while the Pareto-optimal solutions for surfactant-modified nano-organic working fluid is obtained. Results indicate that the evaporation heat transfer coefficient presents a parabolic trend with outlet dryness, while the condensation heat transfer coefficient increases with the mass flow rate. Increasing the evaporation heat transfer coefficient will deteriorate the condensation heat transfer coefficient. The optimal evaporation heat transfer coefficients and condensation heat transfer coefficients for 0.4 %SDBS + 0.1 %TiO₂/R123, 0.3 %CTAB + 0.1 %TiO₂/R123, and 0.3 %Span80 + 0.1 %TiO₂/R123 are 3986.03 W/(m²·K) and 851.23 W/(m²·K), 4139.71 W/(m²·K) and 825.25 W/(m²·K), and 4180.3 W/(m²·K) and 724.32 W/(m²·K), which are 23.76 % higher and 38.01 % higher, 28.53 % higher and 33.79 % higher, 29.79 % higher and 17.44 % higher than that of 0.1 %TiO₂/R123 of 3220.88 W/(m²·K) and 616.78 W/(m²·K), respectively. The nano-organic working fluid with Span80 demonstrates superior performance due to its relatively high comprehensive heat transfer coefficients for both evaporation and condensation.</div></div>","PeriodicalId":11664,"journal":{"name":"Energy Conversion and Management","volume":"333 ","pages":"Article 119815"},"PeriodicalIF":9.9,"publicationDate":"2025-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143858788","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multi-parameter experimental study of a tesla turbine applied to an organic Rankine cycle system for low-grade heat utilisation","authors":"Shiyang Teng ,&nbsp;Liushuai Li ,&nbsp;Chunjie Yan ,&nbsp;Dou An ,&nbsp;Yang Zhao ,&nbsp;Huan Xi","doi":"10.1016/j.enconman.2025.119824","DOIUrl":"10.1016/j.enconman.2025.119824","url":null,"abstract":"<div><div>In response to the increasing demand for energy efficiency enhancement, the exploitation of low-grade thermal energy through Organic Rankine Cycle (ORC) systems has emerged as a crucial strategy for sustainable energy recovery. However, conventional expanders face limitations in terms of cost-effectiveness and efficiency optimization. This study presents a comprehensive experimental investigation into the performance characteristics of a Tesla turbine, an innovative bladeless expander, integrated within an ORC system operating under low-grade thermal conditions (90–130 °C). A prototype miniature ORC system incorporating a Tesla turbine-generator assembly was developed to systematically evaluate the turbine’s isentropic efficiency, its dynamic interactions with system parameters, and associated mechanical losses. Through a series of controlled experiments, key operational parameters including heat source temperature, pump speed (750–1170 RPM), and load current (0.4–1.9 A) were systematically varied to analyze the isentropic efficiency, power output, and pressure ratio relationships. The experimental results demonstrate that the Tesla turbine achieves a remarkable peak isentropic efficiency of 62.28 % and generates a maximum output power of 31.76 W under the tested conditions, with comprehensive analysis of the system’s heat absorption characteristics. This research represents the first multi-parameter experimental validation of a Tesla turbine in an ORC system, establishing its viability for low-grade heat recovery applications. The findings provide valuable insights for the development of scalable solutions in distributed energy systems and industrial waste heat recovery implementations.</div></div>","PeriodicalId":11664,"journal":{"name":"Energy Conversion and Management","volume":"333 ","pages":"Article 119824"},"PeriodicalIF":9.9,"publicationDate":"2025-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143864948","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Expandable model and size effect of proton exchange membrane fuel cells with elevating temperature and reducing humidity","authors":"Xiyuan Zhang ,&nbsp;Liangfei Xu ,&nbsp;Boyang Yu ,&nbsp;Yuan Yao ,&nbsp;Zunyan Hu ,&nbsp;Jianqiu Li ,&nbsp;Minggao Ouyang","doi":"10.1016/j.enconman.2025.119817","DOIUrl":"10.1016/j.enconman.2025.119817","url":null,"abstract":"<div><div>Proton Exchange Membrane Fuel Cell (PEMFC) has become one of the key power sources for electrical transportation. As the power demand increases, the active area of PEMFC becomes larger. However, under the same operating conditions and with the same materials, performance of commercial large-area fuel cells (LAFCs) differ from those of laboratory-level small-area fuel cells (SAFCs) due to the uneven distribution of internal states, such as gas and water content. This phenomenon is referred to as size effect. Investigating the mechanism of size effect is essential for designing and optimization of LAFCs. In this study, an expandable along-the-channel dynamic model is established, which integrates the mass transport processes along proton transport and channel directions. By adjusting the number of partitions along the channel, in-plane heterogeneity can be simulated considering both accuracy and efficiency. The polarization curves and current density distribution of 44 cm² SAFC and 291 cm² LAFC under different temperatures and cathode inlet humidities are tested. Two models with different number of partitions are calibrated and used to reconstruct internal states of SAFC and LAFC. It is found that water accumulation along the channel and water transfer between anode and cathode can significantly enhance the water content in the membrane and catalyst layers in LAFC. This results in lower membrane resistance and activation polarization at low temperatures compared to SAFC. However, as temperature increases and humidity decreases, the water loss issue becomes more pronounced in LAFC, occurring in the following order: air inlet, air outlet, and central region. Although this contributes to lowering the liquid water content and enhancing oxygen diffusion, its suppression of the oxygen reduction reaction and the resultant increase in membrane resistance are expected to have a dominant effect in LAFC, leading to a significantly lower performance of LAFC than that of SAFC under high temperature and low humidity conditions. This study reveals the intrinsic mechanisms behind performance changes in fuel cells upon scaling up through modeling and experiments, laying the foundation for the optimization of LAFCs.</div></div>","PeriodicalId":11664,"journal":{"name":"Energy Conversion and Management","volume":"333 ","pages":"Article 119817"},"PeriodicalIF":9.9,"publicationDate":"2025-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143855334","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Solar-Driven hybrid dehumidification system with spectrum splitting technology for efficient operation across a broad range of humidity","authors":"Xiaobo Zhang ,&nbsp;Ziyang Guo ,&nbsp;Xiangguo Xu ,&nbsp;Duu-Jong Lee","doi":"10.1016/j.enconman.2025.119779","DOIUrl":"10.1016/j.enconman.2025.119779","url":null,"abstract":"<div><div>Solar-driven dehumidification systems, as a clean and sustainable technology, have attracted much attention. To expand its applications, it is necessary to improve its dehumidification efficiency and range. This study develops a solar-driven hybrid dehumidification system integrated with spectrum splitting technology. Spectrum splitting technology can separate long- and short-wavelength solar radiation, making them convert into electricity and thermal energy concurrently in a decoupled way. Subsequently, a new dehumidification configuration is proposed to efficiently leverage the converted energy, where vacuum membrane dehumidification systems (relying on electricity) and liquid desiccant dehumidification systems (relying on thermal energy) are combined in series to dehumidify the air. Such dehumidification configuration under various operation conditions is theoretically assessed. The results show that solar energy converted electricity is not fully utilized, and the air humidity ratio remains high. An improved configuration is subsequently developed, including additional vacuum membrane modules in the vacuum membrane dehumidification system to further reduce the air humidity ratio and a battery to store the excess electrical energy while handling the intermittency of solar energy. The performance of the improved configuration is theoretically assessed regarding the lowest air humidity ratio, exergy efficiency, and operation duration. The results show that the air humidity ratio can reach below 1 g/kg, meeting most application scenarios. The exergy efficiency can reach up to 6.2 %, representing an increase of up to 100 % compared to previous systems. Moreover, the proposed configuration can operate all day at various humidity levels by optimizing the concentration ratio. The proposed configuration provides a promising way for clean and efficient dehumidification across a broad range of humidity levels.</div></div>","PeriodicalId":11664,"journal":{"name":"Energy Conversion and Management","volume":"333 ","pages":"Article 119779"},"PeriodicalIF":9.9,"publicationDate":"2025-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143855333","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thermodynamic analysis of a modified branched GAX absorption refrigeration cycle","authors":"Manuel Cervantes-Astorga ,&nbsp;Gabriel E. Pando-Martínez ,&nbsp;Daniel Sauceda-Carvajal ,&nbsp;Francisco J. Carranza-Chávez","doi":"10.1016/j.enconman.2025.119800","DOIUrl":"10.1016/j.enconman.2025.119800","url":null,"abstract":"<div><div>Refrigeration and air-conditioning systems are responsible of an important share of the energy consumed by utility companies. The use of absorption refrigeration (AR) driven by renewable heat or waste heat can help to alleviate this situation, nevertheless AR is characterized by low performance. To improve it, advanced AR cycles have been suggested, such as the branched GAX cycle (BGAX) which uses the temperature overlap between the generator and absorber to increase the coefficient of performance (<span><math><mrow><mi>COP</mi></mrow></math></span>). To further improve the <span><math><mrow><mi>COP</mi></mrow></math></span>, in this study it is proposed to replace the throttling valves with expanders in a BGAX cycle employing ammonia-water as working fluid. With the work recovered, a compressor is driven to increase the absorber pressure. In parallel, a reheat process of the weak solution is added. Through the two-stage expansion with reheating, energy is recovered from both liquid and gas streams, overcoming the low-power-output limitation of liquid expanders. The performance of this modified cycle, called EBGAX, is compared with that of the BGAX cycle. The modeling was done through parametric analysis in the software Engineering Equations Solver (EES). The results showed that the EBGAX cycle could operate at higher temperature lifts than the BGAX cycle, achieving also higher <span><math><mrow><mi>COP</mi></mrow></math></span> values at lower generator temperatures. A maximum <span><math><mrow><mi>COP</mi></mrow></math></span> increment of 49.38% was obtained. Moreover, it was observed that the reheating process strongly benefited the cycle performance, especially at low generator temperatures, accounting for up to 18.18% of the <span><math><mrow><mi>COP</mi></mrow></math></span> improvement. However, this effect was lost as the generator temperature rose.</div></div>","PeriodicalId":11664,"journal":{"name":"Energy Conversion and Management","volume":"333 ","pages":"Article 119800"},"PeriodicalIF":9.9,"publicationDate":"2025-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143855332","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Machine learning-driven product prediction and process optimization for catalytic pyrolysis of polyolefin plastics","authors":"Hualiang Li ,&nbsp;Zhenzhen Wu ,&nbsp;Hongyuan He ,&nbsp;Shi Feng ,&nbsp;Yunqing Zhou ,&nbsp;Chuanqi Shi ,&nbsp;Xin Tu ,&nbsp;Jianhua Yan ,&nbsp;Hao Zhang","doi":"10.1016/j.enconman.2025.119789","DOIUrl":"10.1016/j.enconman.2025.119789","url":null,"abstract":"<div><div>Pyrolysis offers a sustainable pathway to valorize plastic waste into value-added products, yet its experimental exploration remains costly and time-intensive. In this study, five machine learning models were developed to predict, interpret, and optimize both thermal and catalytic pyrolysis of polyolefin plastics, utilizing 511 data points collected from 63 articles published between 2006 and 2023. Among these models, extreme gradient boosting regression exhibited the best performance in product yield prediction. Feature importance and partial dependence analyses identified the impact of reaction temperature and key catalytic parameters (loading, acid properties, and pore structure) of zeolite-based catalysts on gas and oil yields. These features significantly affect the accessibility of active sites and molecular diffusion, and thus the occurrence of secondary reactions. The results showed that selecting an appropriate catalyst with proper loading, and optimizing the reaction temperature can effectively regulate the catalytic pyrolysis process to achieve the desired product distribution. At moderate reaction temperatures (∼450 °C), microporous zeolite-based catalysts with moderate acidity promoted gas production, while lower temperatures (&lt;400 °C), higher acidity, and larger pore sizes favored oil yields. This work provides valuable mechanistic insights into the catalytic pyrolysis of polyolefins and offers guidance for process optimization and catalyst design.</div></div>","PeriodicalId":11664,"journal":{"name":"Energy Conversion and Management","volume":"333 ","pages":"Article 119789"},"PeriodicalIF":9.9,"publicationDate":"2025-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143848257","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Value chain analysis for long-distance transport of low-carbon energy: Liquefied hydrogen, ammonia, and LNG","authors":"Heechang Son ,&nbsp;Juyoung Oh ,&nbsp;Jinjoo An ,&nbsp;Youngsub Lim","doi":"10.1016/j.enconman.2025.119807","DOIUrl":"10.1016/j.enconman.2025.119807","url":null,"abstract":"<div><div>Economically transporting low-carbon energy to resource-poor regions is essential to achieving a hydrogen economy for a sustainable society. Recently, liquefied hydrogen and ammonia have gained attention as hydrogen carriers. The aim of this study is to compare the greenhouse gas intensities and costs of liquefied hydrogen and ammonia supply chains as energy carriers for blue hydrogen. Additionally, this study compares these two supply chains with the existing liquefied natural gas supply chain. Accordingly, life cycle and techno-economic assessments are performed based on the analysis of material and energy balance data for the three supply chains. As a result, liquefied hydrogen shows improvements of approximately 7% and 15% over ammonia in terms of greenhouse gas intensity and cost, respectively. However, if ammonia is used directly as a fuel rather than being converted to hydrogen, the ammonia supply chain demonstrates improvements of approximately 13% and 15% in terms of greenhouse gas intensity and cost, respectively, compared to the liquefied hydrogen supply chain. In comparison to the liquefied natural gas supply chain, both liquefied hydrogen and ammonia offer little advantage in terms of greenhouse gas intensity, primarily due to significant indirect greenhouse gas emissions associated with the blue hydrogen production. From a cost perspective, liquefied natural gas holds a significant advantage. These results provide insights into the need for improvements in process efficiency and the supply of clean energy for a sustainable hydrogen economy and highlight that the choice of an appropriate hydrogen carrier can vary depending on the end user.</div></div>","PeriodicalId":11664,"journal":{"name":"Energy Conversion and Management","volume":"333 ","pages":"Article 119807"},"PeriodicalIF":9.9,"publicationDate":"2025-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143850802","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Excess energy management and techno-economic analysis of optimal designed isolated microgrid with reliability and environmental aspects","authors":"Subhash Yadav ,&nbsp;Pradeep Kumar ,&nbsp;Ashwani Kumar","doi":"10.1016/j.enconman.2025.119772","DOIUrl":"10.1016/j.enconman.2025.119772","url":null,"abstract":"<div><div>Isolated microgrids generate excess energy (<em>Pexg</em>) up to 70.1% of total generation, disturbing supply reliability and protection systems. This study presents the <em>Pexg</em> management, optimal design, and techno-economic-environmental analysis in a Hybrid Renewable Energy System (HRES) based isolated microgrid. The optimal sizing is obtained with the minimization of Levelized Cost Of Energy (LCOE), subject to Deficiency of Power Supply Probability (DPSP), and Percentage of Excess Power Generation (PEPG) to maintain the supply reliability and restrict the <em>Pexg</em> generation. The outage rate of Solar Photovoltaic (SPV) and Wind Turbine (WT) units is also considered to obtain the microgrid design. The proposed model is optimized using the African Vultures Optimization Algorithm <strong>(</strong>AVOA), Dragonfly Algorithm (DA), and Grey Wolf Optimization algorithm (GWO). Results show that GWO performs superior to AVOA and DA in standings of execution time and accuracy. The proposed microgrid with energy management techniques restricts the <em>Pexg</em> at 4.84% and 9.64% for Case-A and Case-B, respectively. The minimized LCOE of most techno-economical-environmentally friendly configuration SPV-WT-BG-BES is 0.2414 $/kWh and 0.1133 $/kWh for Case-A and Case-B, respectively, obtained with GWO. This configuration reduces the GHG emissions by 76.09% and 89.33% for Case-A and Case-B, respectively. The sensitivity analysis shows that LCOE varies significantly with the growth in load demand and capital costs. The CO₂ emissions increase almost linearly with the raise in load growth. Thus, the proposed isolated microgrid design offers a techno-economically-environmental friendly system as it offers minimum LCOE, lowest <em>Pexg</em>, high supply reliability, and 100% Renewable Energy Fraction (REF).</div></div>","PeriodicalId":11664,"journal":{"name":"Energy Conversion and Management","volume":"333 ","pages":"Article 119772"},"PeriodicalIF":9.9,"publicationDate":"2025-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143844536","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cooperative optimization algorithm for wind turbine airfoil design and numerical validation of blade aerodynamic and flutter performance","authors":"Hongjie Su ,&nbsp;Jianlong Ma ,&nbsp;Jianwen Wang ,&nbsp;Zhiying Gao ,&nbsp;Qiuyan Li ,&nbsp;Wenli Pan ,&nbsp;Long Yang","doi":"10.1016/j.enconman.2025.119818","DOIUrl":"10.1016/j.enconman.2025.119818","url":null,"abstract":"<div><div>Wind turbines hold substantial promise for harnessing wind energy, yet the blades endure severe unsteady aerodynamic loads due to prolonged operation in complex environments. These loads adversely affect both aerodynamic and structural performance. The aerodynamic and structural properties of airfoils are critical determinants of overall blade effectiveness. To enhance aerodynamic and anti-flutter performance, this study proposed an optimization approach for wind turbine airfoils using a Hybrid Bi-Directional Cooperative Constrained Multi-Objective Evolutionary Algorithm (HBC-COMEA). Airfoil geometries were parameterized via Non-Uniform Rational B-Splines (NURBS), and optimization was performed with the lift-to-drag ratio and polar moment of inertia as the objective functions, subject to constraints on maximum airfoil thickness. The NREL 5 MW wind turbine blade served as the study model, with optimizations performed on airfoils located at different blade sections, including NACA64618 (18 % relative thickness), DU93-W-210 (21 % relative thickness), and DU91-W2-250 (25 % relative thickness). The results demonstrated improvements in both aerodynamic performance and polar moment of inertia. Replacing the original airfoils with the optimized ones led to a 5.07 % increase in blade torque at the rated wind speed. Additionally, flutter analysis indicated a 24 % enhancement in the flutter boundary and a significant reduction in the torsional vibration amplitude of the blade. These findings validate that the proposed optimization method markedly improves overall blade performance, offering a promising approach for optimizing airfoils in large wind turbine blades.</div></div>","PeriodicalId":11664,"journal":{"name":"Energy Conversion and Management","volume":"333 ","pages":"Article 119818"},"PeriodicalIF":9.9,"publicationDate":"2025-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143844535","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Influence of external thermal resistance on thermoelectric cooling in thermal management systems: Operating modes and material selection","authors":"Junyoung Park,&nbsp;Sang J. Park,&nbsp;Ki Mun Bang,&nbsp;Hyungyu Jin","doi":"10.1016/j.enconman.2025.119806","DOIUrl":"10.1016/j.enconman.2025.119806","url":null,"abstract":"<div><div>Embedding thermoelectric coolers (TECs) within thermal management systems is a promising approach for addressing localized heat. The required thermoelectric (TE) material properties for achieving a high cooling rate depend on the operating mode of TECs—refrigeration or active cooling—which is determined by the internal Fourier heat direction within the TE legs. Therefore, analyzing the operating mode should be prioritized before employing TECs to ensure the selection of TE materials that maximize cooling performance. However, the influence of external thermal resistances has often been neglected, leading to misclassification of TEC operating modes and the selection of inappropriate TE materials, ultimately resulting in lower cooling rates. To address this, we analyze operating modes of TECs while accounting for external thermal resistances. Our findings reveal that TECs operate in active cooling mode only if the thermal conductivity of the TE material exceeds a specific threshold; otherwise, they operate in refrigeration mode. This threshold is determined by both material properties and external thermal resistances. Building on this insight, we identify the operating mode that achieves the highest cooling rate for given external thermal resistances and establish a criterion for selecting optimal TE materials. Experimental validation closely aligns with our theoretical analysis, further confirming our results. This study provides fundamental insights into the influence of external thermal resistances on TEC operating modes, facilitating the effective integration of TECs into thermal management systems by optimizing TE material selection.</div></div>","PeriodicalId":11664,"journal":{"name":"Energy Conversion and Management","volume":"333 ","pages":"Article 119806"},"PeriodicalIF":9.9,"publicationDate":"2025-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143848192","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}