Pub Date : 2026-01-04DOI: 10.1016/j.applthermaleng.2026.129709
Zhe Xu , Zhenhua Quan , Xinglu He , Yunfei Hao , Wenjie Deng , Ze Bai , Yaohua Zhao
To support China's “Dual Carbon” goals, this study proposes a direct-expansion radiant–convective terminal that integrates a micro heat pipe array (MHPA) with a microchannel heat exchanger (MCHE). This design addresses the slow thermal response and non-uniform temperature distribution of conventional systems. The heating performance of the terminal was experimentally evaluated under a range of wind speeds and compressor speeds. The results show a markedly faster thermal response: the terminal reached a stable state 62–72 % sooner than conventional radiant walls, stabilizing within 50 min, and achieved a coefficient of performance (COP) of 3.2. Forced convection dominated heat transfer (71.8 %), followed by natural convection (15.8 %) and radiation (12.4 %). Increasing the wind speed to 2.5 m/s enhanced the heat transfer capacity by up to 39.9 %, enabling flexible switching between convective- and radiant-dominant heating. In radiant mode, the system maintained a vertical temperature gradient of only 3.1 °C, indicating improved thermal comfort. An optimal trade-off between heating capacity and efficiency was obtained at 40–45 rps. Overall, the proposed terminal provides a viable approach for rapid, efficient, and comfortable distributed heating and can contribute to carbon-reduction targets.
{"title":"Experimental study on the performance of direct-expansion radiant-convective terminal heating based on micro heat pipe array","authors":"Zhe Xu , Zhenhua Quan , Xinglu He , Yunfei Hao , Wenjie Deng , Ze Bai , Yaohua Zhao","doi":"10.1016/j.applthermaleng.2026.129709","DOIUrl":"10.1016/j.applthermaleng.2026.129709","url":null,"abstract":"<div><div>To support China's “Dual Carbon” goals, this study proposes a direct-expansion radiant–convective terminal that integrates a micro heat pipe array (MHPA) with a microchannel heat exchanger (MCHE). This design addresses the slow thermal response and non-uniform temperature distribution of conventional systems. The heating performance of the terminal was experimentally evaluated under a range of wind speeds and compressor speeds. The results show a markedly faster thermal response: the terminal reached a stable state 62–72 % sooner than conventional radiant walls, stabilizing within 50 min, and achieved a coefficient of performance (COP) of 3.2. Forced convection dominated heat transfer (71.8 %), followed by natural convection (15.8 %) and radiation (12.4 %). Increasing the wind speed to 2.5 m/s enhanced the heat transfer capacity by up to 39.9 %, enabling flexible switching between convective- and radiant-dominant heating. In radiant mode, the system maintained a vertical temperature gradient of only 3.1 °C, indicating improved thermal comfort. An optimal trade-off between heating capacity and efficiency was obtained at 40–45 rps. Overall, the proposed terminal provides a viable approach for rapid, efficient, and comfortable distributed heating and can contribute to carbon-reduction targets.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"288 ","pages":"Article 129709"},"PeriodicalIF":6.9,"publicationDate":"2026-01-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145922325","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 : 2026-01-04DOI: 10.1016/j.applthermaleng.2025.129655
Tianjun Liao, Chao Fan
This study presents a framework for optimizing InAs-based intermediate-band thermophotovoltaic cells (IB-TPVCs) by enabling sub-bandgap photon absorption and carrier excitation. The transfer matrix method, integrated with the Drude–Lorentz model, is developed to quantify the angle- and wavelength-dependent absorptivity of multilayer structures for both transverse electric (TE) and transverse magnetic (TM) modes. The absorption spectra for TE mode exhibits distinct oscillatory peaks and valleys, which are caused by optical properties, structural parameters, interference, and resonance effects. The TM mode achieves stronger absorption at specific wavelengths and angles due to surface plasmon resonance and enhanced optical coupling. The spectral photon fluxes are calculated by combining the layer absorptivity with the blackbody radiation spectrum given by Planck's law. Furthermore, the internal quantum efficiency is examined as a function of both the absorber thickness and the photon wavelength. Based on these spectral and efficiency parameters, the short-circuit current density spectrum is calculated. The net current density is then determined by accounting for radiative, non-radiative, and dark current losses. Local optimization is performed by tuning the doping concentration under fixed structural and temperature conditions, while global strategies for maximizing power density and efficiency offer key insights for advancing TPV technology.
{"title":"Thermal radiation-matter interaction analysis and optimal design of InAs-based intermediate-band thermophotovoltaic cells","authors":"Tianjun Liao, Chao Fan","doi":"10.1016/j.applthermaleng.2025.129655","DOIUrl":"10.1016/j.applthermaleng.2025.129655","url":null,"abstract":"<div><div>This study presents a framework for optimizing InAs-based intermediate-band thermophotovoltaic cells (IB-TPVCs) by enabling sub-bandgap photon absorption and carrier excitation. The transfer matrix method, integrated with the Drude–Lorentz model, is developed to quantify the angle- and wavelength-dependent absorptivity of multilayer structures for both transverse electric (TE) and transverse magnetic (TM) modes. The absorption spectra for TE mode exhibits distinct oscillatory peaks and valleys, which are caused by optical properties, structural parameters, interference, and resonance effects. The TM mode achieves stronger absorption at specific wavelengths and angles due to surface plasmon resonance and enhanced optical coupling. The spectral photon fluxes are calculated by combining the layer absorptivity with the blackbody radiation spectrum given by Planck's law. Furthermore, the internal quantum efficiency is examined as a function of both the absorber thickness and the photon wavelength. Based on these spectral and efficiency parameters, the short-circuit current density spectrum is calculated. The net current density is then determined by accounting for radiative, non-radiative, and dark current losses. Local optimization is performed by tuning the doping concentration under fixed structural and temperature conditions, while global strategies for maximizing power density and efficiency offer key insights for advancing TPV technology.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"288 ","pages":"Article 129655"},"PeriodicalIF":6.9,"publicationDate":"2026-01-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145922205","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 : 2026-01-04DOI: 10.1016/j.applthermaleng.2026.129705
Mohammad Javad Moradi, Hamzeh Hajiloo
This study presents a simple yet accurate data-driven model for generating complete compartment fire heat release rate (HRR)–time curves and, from these, predicting temperature–time histories through numerical simulation. The approach is based on 72 full-scale compartment fire tests without combustible linings. Using symbolic regression, a transparent machine learning technique, a concise equation was developed to estimate the maximum HRR (Qmax) from fuel load and ventilation characteristics. Qmax, along with other key fire development points, was used to construct a three-phase growth–plateau–decay HRR curve, which was then applied in CFAST to obtain temperature–time profiles. Model validation against experimental data yielded an R2 of 84.9 % with an RMSE of 0.99 MW for Qmax prediction. Validation against 61 full-scale tests with temperature measurements showed that the proposed model predicted peak temperatures with an RMSE of 271 °C. In comparison, the Eurocode parametric fire (EcPF) model showed the same accuracy, but it applied to a narrower range of compartment conditions. All components of this study were implemented in a simple software tool for performance-based and risk-informed fire design.
{"title":"Modeling compartment fire Heat Release Rate and temperature development: An alternative to the Eurocode parametric fire","authors":"Mohammad Javad Moradi, Hamzeh Hajiloo","doi":"10.1016/j.applthermaleng.2026.129705","DOIUrl":"10.1016/j.applthermaleng.2026.129705","url":null,"abstract":"<div><div>This study presents a simple yet accurate data-driven model for generating complete compartment fire heat release rate (HRR)–time curves and, from these, predicting temperature–time histories through numerical simulation. The approach is based on 72 full-scale compartment fire tests without combustible linings. Using symbolic regression, a transparent machine learning technique, a concise equation was developed to estimate the maximum HRR (Q<sub>max</sub>) from fuel load and ventilation characteristics. Q<sub>max</sub>, along with other key fire development points, was used to construct a three-phase growth–plateau–decay HRR curve, which was then applied in CFAST to obtain temperature–time profiles. Model validation against experimental data yielded an R<sup>2</sup> of 84.9 % with an RMSE of 0.99 MW for Q<sub>max</sub> prediction. Validation against 61 full-scale tests with temperature measurements showed that the proposed model predicted peak temperatures with an RMSE of 271 °C. In comparison, the Eurocode parametric fire (EcPF) model showed the same accuracy, but it applied to a narrower range of compartment conditions. All components of this study were implemented in a simple software tool for performance-based and risk-informed fire design.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"289 ","pages":"Article 129705"},"PeriodicalIF":6.9,"publicationDate":"2026-01-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145915249","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 : 2026-01-03DOI: 10.1016/j.applthermaleng.2025.129652
Nurul Nadia Mohd Zawawi , Abdul Rahman Muhammad Aminullah , Wan Hamzah Azmi , Hafiz Muhammad Ali
Electric vehicles (EVs) increasingly rely on electric-drive compressors (EDCs), where lubricant behaviour plays a decisive role in determining automotive air-conditioning (AAC) efficiency, cooling performance, and overall energy consumption. However, the compatibility and thermodynamic influence of different compressor lubricants on R1234yf-based EV-AAC systems remain insufficiently explored. This study experimentally evaluates the performance of an EDC-driven AAC system using R1234yf and three commercially available compressor lubricants (PAO, PVE and POE) across varied compressor speeds and refrigerant charges. The test rig consisted of an EDC unit, a condenser, an evaporator, an expansion valve, and a refrigerant–lubricant circulation loop. Results show that PAO consistently outperformed PVE and POE, exhibiting the lowest power consumption, highest cooling output, and strongest thermodynamic efficiency. At high speeds, PVE required up to 24 % more power than PAO, while POE consumed almost 14 % more. PAO also achieved the greatest heat-absorption capability (148 kJ/kg at 2000 rpm) and delivered the highest cooling capacity at peak load (826 W at 5000 rpm). In contrast, the POE cooling capacity was 34 % lower than that of PAO at 5000 rpm and 180 g charge. Correspondingly, the coefficient of performance (COP) of PVE and POE decreased by 15 % and 12 %, respectively, compared with PAO under identical conditions. These findings demonstrate that lubricant selection has a substantial and quantifiable impact on EV-AAC efficiency, and PAO emerges as the most suitable candidate for R1234yf-based electric-driven systems. Therefore, lubricant formulation should be treated as a critical design parameter in the development of future EV thermal-management and AAC systems.
{"title":"Performance comparison of electric vehicle air-conditioning system using R1234yf with various compressor lubricants","authors":"Nurul Nadia Mohd Zawawi , Abdul Rahman Muhammad Aminullah , Wan Hamzah Azmi , Hafiz Muhammad Ali","doi":"10.1016/j.applthermaleng.2025.129652","DOIUrl":"10.1016/j.applthermaleng.2025.129652","url":null,"abstract":"<div><div>Electric vehicles (EVs) increasingly rely on electric-drive compressors (EDCs), where lubricant behaviour plays a decisive role in determining automotive air-conditioning (AAC) efficiency, cooling performance, and overall energy consumption. However, the compatibility and thermodynamic influence of different compressor lubricants on R1234yf-based EV-AAC systems remain insufficiently explored. This study experimentally evaluates the performance of an EDC-driven AAC system using R1234yf and three commercially available compressor lubricants (PAO, PVE and POE) across varied compressor speeds and refrigerant charges. The test rig consisted of an EDC unit, a condenser, an evaporator, an expansion valve, and a refrigerant–lubricant circulation loop. Results show that PAO consistently outperformed PVE and POE, exhibiting the lowest power consumption, highest cooling output, and strongest thermodynamic efficiency. At high speeds, PVE required up to 24 % more power than PAO, while POE consumed almost 14 % more. PAO also achieved the greatest heat-absorption capability (148 kJ/kg at 2000 rpm) and delivered the highest cooling capacity at peak load (826 W at 5000 rpm). In contrast, the POE cooling capacity was 34 % lower than that of PAO at 5000 rpm and 180 g charge. Correspondingly, the coefficient of performance (COP) of PVE and POE decreased by 15 % and 12 %, respectively, compared with PAO under identical conditions. These findings demonstrate that lubricant selection has a substantial and quantifiable impact on EV-AAC efficiency, and PAO emerges as the most suitable candidate for R1234yf-based electric-driven systems. Therefore, lubricant formulation should be treated as a critical design parameter in the development of future EV thermal-management and AAC systems.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"288 ","pages":"Article 129652"},"PeriodicalIF":6.9,"publicationDate":"2026-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145922055","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 : 2026-01-03DOI: 10.1016/j.applthermaleng.2026.129707
Xingyi Li , Changqing Du , Jie Zhao , Yifeng Hu
Water–gas management and control stability under dynamic operating conditions are critical factors governing the efficiency and durability of proton exchange membrane fuel cell (PEMFC) systems for automotive applications. This study investigates the coupled water–gas transport behavior and transient performance evolution of an automotive PEMFC system subjected to dynamic load variations. Controlled load-change experiments were conducted across different load levels and amplitudes to elucidate the mechanisms by which dynamic disturbances influence water migration and system performance. The results indicate that moderate load fluctuations effectively promote the removal of liquid water in the cathode flow field, alleviate local flooding, and enable self-recovery of cell performance. Based on these findings, a dynamic load-modulation strategy is proposed, which improves the system output voltage and cell uniformity by 1.6 % and 42.3 %, respectively, compared with the initial state, confirming its effectiveness in performance and consistency recovery. It is further observed that the system achieves the best transient stability and cell-to-cell consistency when operating at medium load levels with small-amplitude load variations. In addition, load variations exhibit pronounced asymmetry: load-increasing operations are more prone to inducing transient instability, whereas load-decreasing processes tend to amplify inter-cell performance deviation. Under the constraint of limited air-compressor response capability, increasing the steady-state cathode pressure proves more effective than increasing airflow in enhancing transient stability and cell consistency. Overall, this work elucidates the dynamic water–gas interaction characteristics of PEMFC systems and proposes engineering-feasible dynamic operating and cathode parameter-optimization strategies to enhance their dynamic adaptability and long-term operational stability in automotive applications.
{"title":"Dynamic load effects on performance stability and cell consistency in automotive PEM fuel cell systems","authors":"Xingyi Li , Changqing Du , Jie Zhao , Yifeng Hu","doi":"10.1016/j.applthermaleng.2026.129707","DOIUrl":"10.1016/j.applthermaleng.2026.129707","url":null,"abstract":"<div><div>Water–gas management and control stability under dynamic operating conditions are critical factors governing the efficiency and durability of proton exchange membrane fuel cell (PEMFC) systems for automotive applications. This study investigates the coupled water–gas transport behavior and transient performance evolution of an automotive PEMFC system subjected to dynamic load variations. Controlled load-change experiments were conducted across different load levels and amplitudes to elucidate the mechanisms by which dynamic disturbances influence water migration and system performance. The results indicate that moderate load fluctuations effectively promote the removal of liquid water in the cathode flow field, alleviate local flooding, and enable self-recovery of cell performance. Based on these findings, a dynamic load-modulation strategy is proposed, which improves the system output voltage and cell uniformity by 1.6 % and 42.3 %, respectively, compared with the initial state, confirming its effectiveness in performance and consistency recovery. It is further observed that the system achieves the best transient stability and cell-to-cell consistency when operating at medium load levels with small-amplitude load variations. In addition, load variations exhibit pronounced asymmetry: load-increasing operations are more prone to inducing transient instability, whereas load-decreasing processes tend to amplify inter-cell performance deviation. Under the constraint of limited air-compressor response capability, increasing the steady-state cathode pressure proves more effective than increasing airflow in enhancing transient stability and cell consistency. Overall, this work elucidates the dynamic water–gas interaction characteristics of PEMFC systems and proposes engineering-feasible dynamic operating and cathode parameter-optimization strategies to enhance their dynamic adaptability and long-term operational stability in automotive applications.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"289 ","pages":"Article 129707"},"PeriodicalIF":6.9,"publicationDate":"2026-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145924477","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 : 2026-01-03DOI: 10.1016/j.applthermaleng.2025.129617
Jifeng Huang, Bo Kong, Qitai Eri, Yong Wang, Jiaan Liu, Siqi Sun
Infrared stealth performance has grown increasingly critical for modern aircraft. Low-observable exhaust systems can suppress infrared radiation (IR) by cooling high-temperature engine components and enhancing the mixing of exhaust plumes with ambient air, thereby improving the survivability of combat aircraft. This study designed infrared stealth measures for both axisymmetric and two-dimensional exhaust systems, including modifying the structure of the heatshield and trailing edge shaping. The modified exhaust systems were installed on a micro-turbojet engine for testing, where wall and exhaust plume parameters were measured. Fourier-transform infrared (FTIR) spectroscopy was employed to measure the infrared characteristic of the exhaust systems. In addition, numerical simulations were also employed to assist in analyzing the infrared suppression mechanism. The experiment results demonstrated the axisymmetric exhaust system achieved peak infrared reductions of 31.7 %. The two-dimensional exhaust system demonstrated enhanced performance, achieving peak significant infrared suppression of 57.6 % and 30.3 % in the vertical and horizontal plane. Successful infrared suppression in both configurations is due to the exit of the heatshield moving to the low-pressure area, which facilitated bypass flow entry into the heatshield channel, enhancing cooling of the divergent section walls. Because of the abrupt transitions in the two-dimensional nozzle, the stealth measures proved more effective in suppressing IR for the two-dimensional exhaust system. However, these measures incur a certain negative impact on thrust performance. The research advances the understanding of integrated thermal management and infrared stealth for next-generation combat aircraft.
{"title":"Experimental and numerical investigation of infrared stealth measures on flow and infrared characteristics in turbofan exhaust systems","authors":"Jifeng Huang, Bo Kong, Qitai Eri, Yong Wang, Jiaan Liu, Siqi Sun","doi":"10.1016/j.applthermaleng.2025.129617","DOIUrl":"10.1016/j.applthermaleng.2025.129617","url":null,"abstract":"<div><div>Infrared stealth performance has grown increasingly critical for modern aircraft. Low-observable exhaust systems can suppress infrared radiation (IR) by cooling high-temperature engine components and enhancing the mixing of exhaust plumes with ambient air, thereby improving the survivability of combat aircraft. This study designed infrared stealth measures for both axisymmetric and two-dimensional exhaust systems, including modifying the structure of the heatshield and trailing edge shaping. The modified exhaust systems were installed on a micro-turbojet engine for testing, where wall and exhaust plume parameters were measured. Fourier-transform infrared (FTIR) spectroscopy was employed to measure the infrared characteristic of the exhaust systems. In addition, numerical simulations were also employed to assist in analyzing the infrared suppression mechanism. The experiment results demonstrated the axisymmetric exhaust system achieved peak infrared reductions of 31.7 %. The two-dimensional exhaust system demonstrated enhanced performance, achieving peak significant infrared suppression of 57.6 % and 30.3 % in the vertical and horizontal plane. Successful infrared suppression in both configurations is due to the exit of the heatshield moving to the low-pressure area, which facilitated bypass flow entry into the heatshield channel, enhancing cooling of the divergent section walls. Because of the abrupt transitions in the two-dimensional nozzle, the stealth measures proved more effective in suppressing IR for the two-dimensional exhaust system. However, these measures incur a certain negative impact on thrust performance. The research advances the understanding of integrated thermal management and infrared stealth for next-generation combat aircraft.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"289 ","pages":"Article 129617"},"PeriodicalIF":6.9,"publicationDate":"2026-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145924530","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 : 2026-01-03DOI: 10.1016/j.applthermaleng.2025.129687
Sohaib Hassan Mohammed, Omar M. Yousif, Ayad S. Abedalh
Approximately 30 % of food spoils in developing countries due to unreliable electricity supply for refrigeration, necessitating alternative cooling solutions for off-grid regions. This study presents the first comprehensive investigation of 3-NORIT PK1 activated carbon paired with methanol for solar adsorption ice-making, extending beyond previous literature by characterizing this specific working pair under actual semi-arid climatic conditions and validating the Dubinin-Radushkevich equation through extensive field testing. A square meter flat-plate solar collector system was designed and tested through over 80 experiments in Mosul City, examining methanol-to-activated carbon mass ratios of 0.8 and 1.2 at operating pressures of 3 and 5 kPa. Temperature measurements were recorded at 18 system points using multi-channel data loggers with 0.0063 °C accuracy. Results demonstrated that 3-NORIT PK1 achieved 0.8 kg methanol per kilogram activated carbon adsorption capacity, with prediction errors below 5 %. At optimal conditions of 0.8 mass ratio and 3 kPa pressure, the system produced 0.375 kg condensed methanol, maintained 0 °C for 2 h, achieved maximum coefficient of performance of 0.43, and generated 1 kg ice daily. The system provides a viable electricity-free refrigeration solution for food preservation in regions lacking reliable power infrastructure.
{"title":"Use of adsorption pair of activated carbon and methanol in solar ice maker","authors":"Sohaib Hassan Mohammed, Omar M. Yousif, Ayad S. Abedalh","doi":"10.1016/j.applthermaleng.2025.129687","DOIUrl":"10.1016/j.applthermaleng.2025.129687","url":null,"abstract":"<div><div>Approximately 30 % of food spoils in developing countries due to unreliable electricity supply for refrigeration, necessitating alternative cooling solutions for off-grid regions. This study presents the first comprehensive investigation of 3-NORIT PK1 activated carbon paired with methanol for solar adsorption ice-making, extending beyond previous literature by characterizing this specific working pair under actual semi-arid climatic conditions and validating the Dubinin-Radushkevich equation through extensive field testing. A square meter flat-plate solar collector system was designed and tested through over 80 experiments in Mosul City, examining methanol-to-activated carbon mass ratios of 0.8 and 1.2 at operating pressures of 3 and 5 kPa. Temperature measurements were recorded at 18 system points using multi-channel data loggers with 0.0063 °C accuracy. Results demonstrated that 3-NORIT PK1 achieved 0.8 kg methanol per kilogram activated carbon adsorption capacity, with prediction errors below 5 %. At optimal conditions of 0.8 mass ratio and 3 kPa pressure, the system produced 0.375 kg condensed methanol, maintained 0 °C for 2 h, achieved maximum coefficient of performance of 0.43, and generated 1 kg ice daily. The system provides a viable electricity-free refrigeration solution for food preservation in regions lacking reliable power infrastructure.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"288 ","pages":"Article 129687"},"PeriodicalIF":6.9,"publicationDate":"2026-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145921980","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 : 2026-01-03DOI: 10.1016/j.applthermaleng.2025.129618
Jun Shu, Binghong Chen, Yan Wang, Yanjing Wu, Qiguo Yang
The development of high-efficiency solar absorbers is of particular importance for solar energy utilization; however, traditional manual optimization requires substantial time. This study proposes an optimization scheme for ultra-broadband solar absorbers based on the coupling of a multilayer perceptron (MLP) with a genetic-particle swarm adaptive algorithm (GPSAA). The scheme achieves a hundredfold improvement in response speed compared to simulations. A total of 12,348 sets of structure-spectrum data were employed to train the MLP model, yielding mean squared errors (MSE) of 1.51 × 10−5 and 1.76 × 10−5 for the training and test sets, respectively, with mean absolute errors (MAE) of 1.2 × 10−3 and 1.4 × 10−3. The coefficient of determination (R2) values reached 0.9975 and 0.9957, thereby enabling high-speed and high-precision mapping from structural parameters to spectral responses. The absorptivity-optimized structure obtained achieves a solar energy absorptivity of 99.49 % across the 280–4000 nm wavelength range. Performance analysis demonstrates that the absorber is insensitive to both the incident angle (θ) and the polarization angle (ϕ). Mechanistic investigations reveal that its high-efficiency absorption stems from free-space impedance matching induced by the coupling effects of surface plasmon resonance (SPR), cavity resonance (CR), and guided mode resonance (GMR). Additionally, considering the influence of actual processing errors on absorption performance, a robustness-optimized structure was designed by comprehensively balancing absorption performance and robustness, achieving a minimum solar energy absorptivity of 99.20 %. The designed framework of the deep learning-coupled optimization algorithm proposed in this work provides a universal methodology for the efficient development of metamaterial absorbers, holding significant engineering application value in the field of solar photothermal conversion.
{"title":"Deep learning-assisted design of MXene-based ultra-broadband absorber for full spectrum solar energy harvesting","authors":"Jun Shu, Binghong Chen, Yan Wang, Yanjing Wu, Qiguo Yang","doi":"10.1016/j.applthermaleng.2025.129618","DOIUrl":"10.1016/j.applthermaleng.2025.129618","url":null,"abstract":"<div><div>The development of high-efficiency solar absorbers is of particular importance for solar energy utilization; however, traditional manual optimization requires substantial time. This study proposes an optimization scheme for ultra-broadband solar absorbers based on the coupling of a multilayer perceptron (MLP) with a genetic-particle swarm adaptive algorithm (GPSAA). The scheme achieves a hundredfold improvement in response speed compared to simulations. A total of 12,348 sets of structure-spectrum data were employed to train the MLP model, yielding mean squared errors (MSE) of 1.51 × 10<sup>−5</sup> and 1.76 × 10<sup>−5</sup> for the training and test sets, respectively, with mean absolute errors (MAE) of 1.2 × 10<sup>−3</sup> and 1.4 × 10<sup>−3</sup>. The coefficient of determination (R<sup>2</sup>) values reached 0.9975 and 0.9957, thereby enabling high-speed and high-precision mapping from structural parameters to spectral responses. The absorptivity-optimized structure obtained achieves a solar energy absorptivity of 99.49 % across the 280–4000 nm wavelength range. Performance analysis demonstrates that the absorber is insensitive to both the incident angle (θ) and the polarization angle (ϕ). Mechanistic investigations reveal that its high-efficiency absorption stems from free-space impedance matching induced by the coupling effects of surface plasmon resonance (SPR), cavity resonance (CR), and guided mode resonance (GMR). Additionally, considering the influence of actual processing errors on absorption performance, a robustness-optimized structure was designed by comprehensively balancing absorption performance and robustness, achieving a minimum solar energy absorptivity of 99.20 %. The designed framework of the deep learning-coupled optimization algorithm proposed in this work provides a universal methodology for the efficient development of metamaterial absorbers, holding significant engineering application value in the field of solar photothermal conversion.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"288 ","pages":"Article 129618"},"PeriodicalIF":6.9,"publicationDate":"2026-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145922177","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 : 2026-01-03DOI: 10.1016/j.applthermaleng.2026.129711
Victor Tomanik, Pau Bares, André Nakaema Aronis, Benjamín Pla
The accelerated adoption of electric vehicles (EVs), driven by a growing global market and sustainability laws, has magnified the importance of Battery Thermal Management Systems (BTMS). The efficacy of these systems, however, is challenged by real-world variables, including traffic patterns, ambient conditions, and driver behavior. This work presents a predictive thermal management strategy that integrates driving and charging phases to minimize energy consumption over a complete trip. Leveraging the vehicle route information to anticipate charging stops and the State of Charge (SOC) allows to proactively adapt the control strategy to the current situation. When a charging event is predicted, the controller preconditions the system and transitions to a charging-optimized strategy that manages the thermal stresses associated with fast charging. The strategy was validated experimentally using a 3.7 kWh battery pack, demonstrating a reduction in BTMS energy consumption compared to a conventional rule-based controller across different drive cycles.
{"title":"Integrated predictive control of battery thermal management in electric vehicles during driving and fast charging","authors":"Victor Tomanik, Pau Bares, André Nakaema Aronis, Benjamín Pla","doi":"10.1016/j.applthermaleng.2026.129711","DOIUrl":"10.1016/j.applthermaleng.2026.129711","url":null,"abstract":"<div><div>The accelerated adoption of electric vehicles (EVs), driven by a growing global market and sustainability laws, has magnified the importance of Battery Thermal Management Systems (BTMS). The efficacy of these systems, however, is challenged by real-world variables, including traffic patterns, ambient conditions, and driver behavior. This work presents a predictive thermal management strategy that integrates driving and charging phases to minimize energy consumption over a complete trip. Leveraging the vehicle route information to anticipate charging stops and the State of Charge (SOC) allows to proactively adapt the control strategy to the current situation. When a charging event is predicted, the controller preconditions the system and transitions to a charging-optimized strategy that manages the thermal stresses associated with fast charging. The strategy was validated experimentally using a 3.7 kWh battery pack, demonstrating a reduction in BTMS energy consumption compared to a conventional rule-based controller across different drive cycles.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"289 ","pages":"Article 129711"},"PeriodicalIF":6.9,"publicationDate":"2026-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145975078","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}
Performance monitoring and proactive prediction are critical safeguards for gas turbine safe operation under extreme conditions. When real component characteristics are unavailable, conventional component-level models (CLMs) exhibit significant error in predicting gas turbine performance during such scenarios. This study focuses on accurately predicting its key performance parameters without component characteristics and low-temperature physics experiments. A 25 MW power generation gas turbine serves as a case study. We gave a specialized network architecture for gas turbine performance digital twins which embed physical knowledge. The coupling layer network creatively transfers temporal modeling to spatial coupling, achieving dynamic decoupling of multi-component physical interactions in gas turbines. Especially, a dimensionless parameter migration framework driven by similarity theory was proposed for the first time, designed to facilitate cross-condition performance prediction and model migration through dimensionless parameters. Using this approach, power turbine outlet temperature prediction error in cold environments decreased from 2.71% to 0.85%. Separate digital twin models for stable power generation and startup were developed based on the dimensionless parameter migration framework. The results demonstrate the effectiveness of the digital twin in enhancing gas turbine operational reliability and efficiency.
{"title":"Similarity theory-driven dimensionless parameter migration framework: Digital twin approach for cross-condition gas turbine performance monitoring","authors":"Chuming Gao , Zilang Huang , Aiyang Yu , Hong Xiao , Zhishu Zhang","doi":"10.1016/j.applthermaleng.2026.129712","DOIUrl":"10.1016/j.applthermaleng.2026.129712","url":null,"abstract":"<div><div>Performance monitoring and proactive prediction are critical safeguards for gas turbine safe operation under extreme conditions. When real component characteristics are unavailable, conventional component-level models (CLMs) exhibit significant error in predicting gas turbine performance during such scenarios. This study focuses on accurately predicting its key performance parameters without component characteristics and low-temperature physics experiments. A 25 MW power generation gas turbine serves as a case study. We gave a specialized network architecture for gas turbine performance digital twins which embed physical knowledge. The coupling layer network creatively transfers temporal modeling to spatial coupling, achieving dynamic decoupling of multi-component physical interactions in gas turbines. Especially, a dimensionless parameter migration framework driven by similarity theory was proposed for the first time, designed to facilitate cross-condition performance prediction and model migration through dimensionless parameters. Using this approach, power turbine outlet temperature prediction error in cold environments decreased from 2.71% to 0.85%. Separate digital twin models for stable power generation and startup were developed based on the dimensionless parameter migration framework. The results demonstrate the effectiveness of the digital twin in enhancing gas turbine operational reliability and efficiency.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"288 ","pages":"Article 129712"},"PeriodicalIF":6.9,"publicationDate":"2026-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145922241","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}
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