Pub Date : 2026-01-12DOI: 10.1016/j.tsep.2026.104506
Uzair Sajjad , Hafiz Muhammad Ali , Naseem Abbas , Wei-Mon Yan
Drying has long been one of the most effective and widely used methods for food preservation. Among various techniques, vacuum freeze drying (VFD) offers the advantage of producing hygienic products while better preserving the original taste, appearance, color, and nutritional content, as well as achieving a higher rehydration rate. This study aims to optimize the VFD process for kiwi fruit to obtain high-quality products with improved appearance, color, taste, and nutritional retention at reduced cost. The Taguchi method was employed to identify optimal process parameters, including slice thickness (5, 7, and 9 mm), ramp rate (0.5, 1.0, and 1.5 °C/min), drying temperature (40, 50, and 60 °C), and drying rate (5, 10, and 15 °C/hr), using an orthogonal array with four factors at three levels each. Drying experiments were conducted above the eutectic point to ensure rapid temperature rise and efficient primary drying. The results showed that vacuum-freeze drying achieved the highest product quality at a slice thickness of 5 mm, a ramp rate of 0.5 ℃/min, a drying temperature of 60 ℃, and a drying rate of 15 ℃/hr.
{"title":"Optimization of Process Parameters for Vacuum Freeze Drying of Kiwi Fruit","authors":"Uzair Sajjad , Hafiz Muhammad Ali , Naseem Abbas , Wei-Mon Yan","doi":"10.1016/j.tsep.2026.104506","DOIUrl":"10.1016/j.tsep.2026.104506","url":null,"abstract":"<div><div>Drying has long been one of the most effective and widely used methods for food preservation. Among various techniques, vacuum freeze drying (VFD) offers the advantage of producing hygienic products while better preserving the original taste, appearance, color, and nutritional content, as well as achieving a higher rehydration rate. This study aims to optimize the VFD process for kiwi fruit to obtain high-quality products with improved appearance, color, taste, and nutritional retention at reduced cost. The Taguchi method was employed to identify optimal process parameters, including slice thickness (5, 7, and 9 mm), ramp rate (0.5, 1.0, and 1.5 °C/min), drying temperature (40, 50, and 60 °C), and drying rate (5, 10, and 15 °C/hr), using an orthogonal array with four factors at three levels each. Drying experiments were conducted above the eutectic point to ensure rapid temperature rise and efficient primary drying. The results showed that vacuum-freeze drying achieved the highest product quality at a slice thickness of 5 mm, a ramp rate of 0.5 ℃/min, a drying temperature of 60 ℃, and a drying rate of 15 ℃/hr.</div></div>","PeriodicalId":23062,"journal":{"name":"Thermal Science and Engineering Progress","volume":"70 ","pages":"Article 104506"},"PeriodicalIF":5.4,"publicationDate":"2026-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145980638","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2026-01-12DOI: 10.1016/j.tsep.2026.104507
Linchao Wang , Yi Xue , Lin Zhu , Xiaoshan Cao , Xue Li , P.G. Ranjith
Liquid nitrogen (LN2)–assisted fracturing has emerged as a promising technique to enhance reservoir permeability and stimulate geothermal energy extraction. This study investigates the progressive degradation of granite under repeated thermal shocks, simulating geothermal conditions by subjecting samples to high-temperature heating followed by rapid LN2 cooling, with cycles ranging from 0 to 20. Mechanical behavior was assessed by uniaxial compression (UCT), Brazilian splitting (BST), and three-point bending (TPBT) tests, with real-time acoustic emission (AE) monitoring employed to track fracture evolution. Results reveal substantial degradation in mechanical properties, with tensile strength and fracture toughness decreasing by up to 67.48 % and 65.51 %, respectively, after 20 thermal cycles. The extent of microstructural damage increases rapidly in the initial cycles, then plateaus after approximately 7–9 cycles, indicating a saturation point in damage development. AE analysis indicates a transition from brittle to more ductile behavior, manifested by increased AE activity, a rise in high-frequency components (>700 kHz), and the development of complex fracture networks. The average frequency (AF)–rise time/amplitude (RA) distribution indicates a growing prevalence of shear-dominated microcracking as cycling progresses. These findings offer new insights into the micro-mechanical mechanisms activated by LN2 cycling and highlight its effectiveness as a thermal stimulation strategy for enhancing the permeability of low-porosity crystalline rocks in geothermal applications.
{"title":"Fracture evolution of granite under cyclic thermal shocks: effects of liquid nitrogen cooling on strength, toughness, and acoustic emission characteristics","authors":"Linchao Wang , Yi Xue , Lin Zhu , Xiaoshan Cao , Xue Li , P.G. Ranjith","doi":"10.1016/j.tsep.2026.104507","DOIUrl":"10.1016/j.tsep.2026.104507","url":null,"abstract":"<div><div>Liquid nitrogen (LN<sub>2</sub>)–assisted fracturing has emerged as a promising technique to enhance reservoir permeability and stimulate geothermal energy extraction. This study investigates the progressive degradation of granite under repeated thermal shocks, simulating geothermal conditions by subjecting samples to high-temperature heating followed by rapid LN<sub>2</sub> cooling, with cycles ranging from 0 to 20. Mechanical behavior was assessed by uniaxial compression (UCT), Brazilian splitting (BST), and three-point bending (TPBT) tests, with real-time acoustic emission (AE) monitoring employed to track fracture evolution. Results reveal substantial degradation in mechanical properties, with tensile strength and fracture toughness decreasing by up to 67.48 % and 65.51 %, respectively, after 20 thermal cycles. The extent of microstructural damage increases rapidly in the initial cycles, then plateaus after approximately 7–9 cycles, indicating a saturation point in damage development. AE analysis indicates a transition from brittle to more ductile behavior, manifested by increased AE activity, a rise in high-frequency components (>700 kHz), and the development of complex fracture networks. The average frequency (AF)–rise time/amplitude (RA) distribution indicates a growing prevalence of shear-dominated microcracking as cycling progresses. These findings offer new insights into the micro-mechanical mechanisms activated by LN<sub>2</sub> cycling and highlight its effectiveness as a thermal stimulation strategy for enhancing the permeability of low-porosity crystalline rocks in geothermal applications.</div></div>","PeriodicalId":23062,"journal":{"name":"Thermal Science and Engineering Progress","volume":"70 ","pages":"Article 104507"},"PeriodicalIF":5.4,"publicationDate":"2026-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146023961","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2026-01-10DOI: 10.1016/j.tsep.2026.104505
Jie Ma , Chuanxiang Gong , Shuai Wang , Haidong Xu , Shuai Yin , Hao Peng
To overcome the performance limitations of traditional twisted oval tubes, the innovative design of eccentrically twisted oval tubes is proposed by introducing the asymmetric geometric disturbances through offsetting the twisted axis. This asymmetric structure can enhance the intensity of the secondary flow and expand the influence area of the secondary flow, thus effectively enhancing heat transfer in the eccentrically twisted oval tube. Based on the k-ω turbulence model, the influences of eccentric parameters on the thermal–hydraulic performance are numerically investigated through the analysis of temperature, pressure, and velocity fields as well as their synergistic interactions. In addition, correlations for the Nusselt number and friction factor are established. The results indicate that the performance evaluation criteria increase with both the eccentric angle and eccentric distance, reaching their maximum values in the direction of the minor axis. Specifically, when the eccentric distance is 7 mm, the Nusselt number increases by 38.12 %, and the performance evaluation criteria value reaches 1.21. This improvement can be attributed to the wall-attached vortex structures induced by the eccentricity of the twisted axis. Simultaneously, strong lateral secondary flows are generated in the eccentric direction, resulting in a 50 % increase in flow intensity compared to that in standard twisted oval tubes. These secondary flows decrease the synergy angle of velocity field and temperature gradient, thereby further contributing to the heat transfer enhancement of the eccentrically twisted oval tubes.
{"title":"Numerical investigation of heat transfer and flow characteristics in eccentrically twisted oval tubes","authors":"Jie Ma , Chuanxiang Gong , Shuai Wang , Haidong Xu , Shuai Yin , Hao Peng","doi":"10.1016/j.tsep.2026.104505","DOIUrl":"10.1016/j.tsep.2026.104505","url":null,"abstract":"<div><div>To overcome the performance limitations of traditional twisted oval tubes, the innovative design of eccentrically twisted oval tubes is proposed by introducing the asymmetric geometric disturbances through offsetting the twisted axis. This asymmetric structure can enhance the intensity of the secondary flow and expand the influence area of the secondary flow, thus effectively enhancing heat transfer in the eccentrically twisted oval tube. Based on the <em>k-ω</em> turbulence model, the influences of eccentric parameters on the thermal–hydraulic performance are numerically investigated through the analysis of temperature, pressure, and velocity fields as well as their synergistic interactions. In addition, correlations for the Nusselt number and friction factor are established. The results indicate that the performance evaluation criteria increase with both the eccentric angle and eccentric distance, reaching their maximum values in the direction of the minor axis. Specifically, when the eccentric distance is 7 mm, the Nusselt number increases by 38.12 %, and the performance evaluation criteria value reaches 1.21. This improvement can be attributed to the wall-attached vortex structures induced by the eccentricity of the twisted axis. Simultaneously, strong lateral secondary flows are generated in the eccentric direction, resulting in a 50 % increase in flow intensity compared to that in standard twisted oval tubes. These secondary flows decrease the synergy angle of velocity field and temperature gradient, thereby further contributing to the heat transfer enhancement of the eccentrically twisted oval tubes.</div></div>","PeriodicalId":23062,"journal":{"name":"Thermal Science and Engineering Progress","volume":"70 ","pages":"Article 104505"},"PeriodicalIF":5.4,"publicationDate":"2026-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145980495","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2026-01-10DOI: 10.1016/j.tsep.2026.104491
M. Laporte-Azcué, D. Pardillos-Pobo, M.R. Rodríguez-Sánchez, D. Santana
This paper deals with the thermomechanical analysis of a molten-salt tubular central receiver in a solar power tower plant using three discretization levels. A coarse-grid model (CGM) considers one representative tube per panel; a fine-grid model (FGM) is run first with the CGM mass-flow setpoint and then with adjusted mass flow to achieve a 565°C outlet. We compare mass flows, temperatures and elastic stresses on the spring equinox, summer solstice, and winter solstice. They serve to assess the receiver durability as equivalent operating days (EODs) resulting from creep-fatigue damage.
The CGM systematically overpredicts the heat transfer fluid flow that the receiver can heat up to 565°C compared to the FGM. Moreover, while panel-average temperatures are captured reasonably, the CGM misses tube-to-tube gradients, and yields higher tube temperatures overall, which amplifies elastic stress error from around + 30% to −15%. The largest error occurs at mid-panel height, which is typically the critical spot durability-wise. For large storage sizes (∼30000 tn), the CGM underestimates panel 1 life in 7.27 years versus the FGM with adjusted flow rate, suggesting unnecessary repairs. In the remaining panels the CGM overpredicts durability, risking earlier-than-predicted failures. In the most concerning panels (2–4) it is up to 2 years. These discrepancies arise from the interplay among temperature, elastic–plastic stress, and stress relaxation. Overall, tube- and panel-level variability undermines generalization from a single representative tube. If a CGM must be used, panel-specific safeguards are recommended; otherwise, the FGM with adjusted flow provides more credible life and cost forecasts.
{"title":"Thermo-mechanical life assessment of solar central receivers: Comparison of coarse and fine grid discretisations","authors":"M. Laporte-Azcué, D. Pardillos-Pobo, M.R. Rodríguez-Sánchez, D. Santana","doi":"10.1016/j.tsep.2026.104491","DOIUrl":"10.1016/j.tsep.2026.104491","url":null,"abstract":"<div><div>This paper deals with the thermomechanical analysis of a molten-salt tubular central receiver in a solar power tower plant using three discretization levels. A coarse-grid model (CGM) considers one representative tube per panel; a fine-grid model (FGM) is run first with the CGM mass-flow setpoint and then with adjusted mass flow to achieve a 565°C outlet. We compare mass flows, temperatures and elastic stresses on the spring equinox, summer solstice, and winter solstice. They serve to assess the receiver durability as equivalent operating days (EODs) resulting from creep-fatigue damage.</div><div>The CGM systematically overpredicts the heat transfer fluid flow that the receiver can heat up to 565°C compared to the FGM. Moreover, while panel-average temperatures are captured reasonably, the CGM misses tube-to-tube gradients, and yields higher tube temperatures overall, which amplifies elastic stress error from around + 30% to −15%. The largest error occurs at mid-panel height, which is typically the critical spot durability-wise. For large storage sizes (∼30000 tn), the CGM underestimates panel 1 life in 7.27 years versus the FGM with adjusted flow rate, suggesting unnecessary repairs. In the remaining panels the CGM overpredicts durability, risking earlier-than-predicted failures. In the most concerning panels (2–4) it is up to 2 years. These discrepancies arise from the interplay among temperature, elastic–plastic stress, and stress relaxation. Overall, tube- and panel-level variability undermines generalization from a single representative tube. If a CGM must be used, panel-specific safeguards are recommended; otherwise, the FGM with adjusted flow provides more credible life and cost forecasts.</div></div>","PeriodicalId":23062,"journal":{"name":"Thermal Science and Engineering Progress","volume":"70 ","pages":"Article 104491"},"PeriodicalIF":5.4,"publicationDate":"2026-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145980635","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2026-01-09DOI: 10.1016/j.tsep.2026.104502
Enes Furkan Örs , Nader Javani
In the current study, a machine learning model for the early detection of thermal runaway in lithium-ion batteries is developed. A nickel manganese cobalt battery is modeled and validated using a multi-scale multi-domain approach. Following model validation, the cell is coated with phase change material and thermal runaway is triggered by an external heat source. In the simulation phase, 144 thermal runaway data are obtained. The voltage, current, phase change material temperature, and battery temperature data are recorded in time-series. After the preparation of the data set, a long short-term memory model is built to predict the thermal runaway at an early stage. Once the prediction model is built, the trade-off relationship between the prediction performance of the model and the training time is investigated in more detail. As a result, it was found that the thermal runaway onset time could be predicted with an error of 5.33 seconds using the first 40 seconds of battery operation data in training and after 70 seconds of model evaluation. Increasing the training time to 120 seconds decreased the thermal runaway onset time prediction error to 2.67 seconds.
{"title":"Early detection of thermal runaway in lithium-ion batteries under extreme conditions using phase change materials","authors":"Enes Furkan Örs , Nader Javani","doi":"10.1016/j.tsep.2026.104502","DOIUrl":"10.1016/j.tsep.2026.104502","url":null,"abstract":"<div><div>In the current study, a machine learning model for the early detection of thermal runaway in lithium-ion batteries is developed. A nickel manganese cobalt battery is modeled and validated using a multi-scale multi-domain approach. Following model validation, the cell is coated with phase change material and thermal runaway is triggered by an external heat source. In the simulation phase, 144 thermal runaway data are obtained. The voltage, current, phase change material temperature, and battery temperature data are recorded in time-series. After the preparation of the data set, a long short-term memory model is built to predict the thermal runaway at an early stage. Once the prediction model is built, the trade-off relationship between the prediction performance of the model and the training time is investigated in more detail. As a result, it was found that the thermal runaway onset time could be predicted with an error of 5.33 seconds using the first 40 seconds of battery operation data in training and after 70 seconds of model evaluation. Increasing the training time to 120 seconds decreased the thermal runaway onset time prediction error to 2.67 seconds.</div></div>","PeriodicalId":23062,"journal":{"name":"Thermal Science and Engineering Progress","volume":"70 ","pages":"Article 104502"},"PeriodicalIF":5.4,"publicationDate":"2026-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145980497","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2026-01-09DOI: 10.1016/j.tsep.2026.104500
Wei Ma , Lina Yu , Yan Zong , Dan Wan
The performance of photovoltaic (PV) panels is highly sensitive to temperature rise, which leads to reduced electrical efficiency and long-term degradation. Passive thermal regulation using phase change materials (PCMs) has emerged as a promising solution, particularly for building-integrated photovoltaic systems. To address these limitations, this study develops a multi-layer, bio-based PCM system enhanced with milled carbon fiber (MCF) nanoparticles to improve both thermal and electrical performance of PV panels. Three novel PCMs are synthesized by blending beeswax and coconut oil in different volume ratios, arranged in a descending melting point order to optimize heat regulation. To enhance thermal conductivity, MCF nanoparticles (0–10 wt%) were uniformly dispersed within the PCM layers. A Response Surface Methodology (RSM) was employed to optimize the PCM layer thicknesses and MCF concentration for maximum electrical efficiency and minimal PV surface temperature. Experimental validation is conducted under realistic operating conditions. Results indicate that PCM 1 (75 % beeswax, 25 % coconut oil) and PCM 2 (50 % beeswax, 50 % coconut oil) reduce PV panel temperature by 2.70 °C and 4.78 °C, respectively, while PCM 3 (25 % beeswax, 75 % coconut oil) exhibits an inverse effect. In the multi-layer configuration, PCM 1 thickness up to 7.5 mm improves electrical efficiency, while PCM 2 and PCM 3 show benefits between 5–15 mm. Optimal MCF nanoparticle incorporation (8.63 wt%) enhanced thermal conductivity, achieving a PV efficiency of 12.22 % and a panel temperature of 38.43 °C.
{"title":"Enhanced thermal regulation in photovoltaic panels using milled carbon fiber-reinforced multi-layer bio-based phase change materials","authors":"Wei Ma , Lina Yu , Yan Zong , Dan Wan","doi":"10.1016/j.tsep.2026.104500","DOIUrl":"10.1016/j.tsep.2026.104500","url":null,"abstract":"<div><div>The performance of photovoltaic (PV) panels is highly sensitive to temperature rise, which leads to reduced electrical efficiency and long-term degradation. Passive thermal regulation using phase change materials (PCMs) has emerged as a promising solution, particularly for building-integrated photovoltaic systems. To address these limitations, this study develops a multi-layer, bio-based PCM system enhanced with milled carbon fiber (MCF) nanoparticles to improve both thermal and electrical performance of PV panels. Three novel PCMs are synthesized by blending beeswax and coconut oil in different volume ratios, arranged in a descending melting point order to optimize heat regulation. To enhance thermal conductivity, MCF nanoparticles (0–10 wt%) were uniformly dispersed within the PCM layers. A Response Surface Methodology (RSM) was employed to optimize the PCM layer thicknesses and MCF concentration for maximum electrical efficiency and minimal PV surface temperature. Experimental validation is conducted under realistic operating conditions. Results indicate that PCM 1 (75 % beeswax, 25 % coconut oil) and PCM 2 (50 % beeswax, 50 % coconut oil) reduce PV panel temperature by 2.70 °C and 4.78 °C, respectively, while PCM 3 (25 % beeswax, 75 % coconut oil) exhibits an inverse effect. In the multi-layer configuration, PCM 1 thickness up to 7.5 mm improves electrical efficiency, while PCM 2 and PCM 3 show benefits between 5–15 mm. Optimal MCF nanoparticle incorporation (8.63 wt%) enhanced thermal conductivity, achieving a PV efficiency of 12.22 % and a panel temperature of 38.43 °C.</div></div>","PeriodicalId":23062,"journal":{"name":"Thermal Science and Engineering Progress","volume":"70 ","pages":"Article 104500"},"PeriodicalIF":5.4,"publicationDate":"2026-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145980642","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2026-01-09DOI: 10.1016/j.tsep.2026.104504
Wenlian Ye , Yang Liu , Yuqin Yan , Lulu Hu , Meihua Su , Yingwen Liu
This study employs multi-objective optimization algorithms to optimize cascade refrigeration systems (CRS) operating at ultra-low temperatures. By comparing the multi-objective grey wolf optimizer (MOGWO), the multi-objective heat exchange algorithm, and the non-dominated sorting genetic algorithm II algorithm, and evaluating them based on various algorithmic metrics, MOGWO is identified as the optimal choice. Subsequently, the study systematically evaluates the capital costs of system components and their impact on the CRS. The objective is to minimize the total economic cost, optimize the inter-stage capacity ratio, and reduce the total exergy destruction while considering the lowest single design parameter and overall system unity. The results reveal that evaporation temperature and intermediate temperature significantly influence system component costs, total exergy destruction, inter-stage capacity ratio, and overall economic expenditure, in contrast to condensing temperature, the cascade temperature difference of the cascade heat exchanger, and the superheat degree of the high-temperature stage. Ultimately, the MOGWO algorithm achieves a 50.83% reduction in exergy destruction (65.26 W to 32.08 W), an inter-stage capacity ratio of 0.23, and annual capital costs of $4015.9. The findings of this study not only enhance the efficiency and economic performance of CRS but also provide valuable references for future design and optimization efforts.
{"title":"Performance analysis and enhancement of cascade refrigeration systems through multi-objective grey wolf optimization algorithm","authors":"Wenlian Ye , Yang Liu , Yuqin Yan , Lulu Hu , Meihua Su , Yingwen Liu","doi":"10.1016/j.tsep.2026.104504","DOIUrl":"10.1016/j.tsep.2026.104504","url":null,"abstract":"<div><div>This study employs multi-objective optimization algorithms to optimize cascade refrigeration systems (CRS) operating at ultra-low temperatures. By comparing the multi-objective grey wolf optimizer (MOGWO), the multi-objective heat exchange algorithm, and the non-dominated sorting genetic algorithm II algorithm, and evaluating them based on various algorithmic metrics, MOGWO is identified as the optimal choice. Subsequently, the study systematically evaluates the capital costs of system components and their impact on the CRS. The objective is to minimize the total economic cost, optimize the inter-stage capacity ratio, and reduce the total exergy destruction while considering the lowest single design parameter and overall system unity. The results reveal that evaporation temperature and intermediate temperature significantly influence system component costs, total exergy destruction, inter-stage capacity ratio, and overall economic expenditure, in contrast to condensing temperature, the cascade temperature difference of the cascade heat exchanger, and the superheat degree of the high-temperature stage. Ultimately, the MOGWO algorithm achieves a 50.83% reduction in exergy destruction (65.26 W to 32.08 W), an inter-stage capacity ratio of 0.23, and annual capital costs of $4015.9. The findings of this study not only enhance the efficiency and economic performance of CRS but also provide valuable references for future design and optimization efforts.</div></div>","PeriodicalId":23062,"journal":{"name":"Thermal Science and Engineering Progress","volume":"70 ","pages":"Article 104504"},"PeriodicalIF":5.4,"publicationDate":"2026-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145980643","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2026-01-08DOI: 10.1016/j.tsep.2026.104501
Saman Zohrabi , Seyed Sadegh Seiiedlou , Iman Golpour , Jochen Mellmann , Barbara Sturm , José Daniel Marcos , Ana M. Blanco-Marigorta , Fardad Didaran , Mark Lefsrud
This study investigates the exergy-based performance and sustainability of a semi-industrial convective dryer equipped with a waste heat recovery unit for drying poplar wood chips. Four key exergy-related indicators, namely exergetic improvement potential (EIP), exergetic sustainability index (ESI), universal exergetic efficiency (UEE), and overall exergetic efficiency (OEE) were examined and then predicted using a feedforward backpropagation multilayer perceptron neural network (FFBP-MLPNN) with the Levenberg-Marquardt (LM) learning algorithm and a single hidden layer. The network evaluated different numbers of neurons in the hidden layer and utilized tansig and purelin activation functions in the hidden and output layers, respectively. Experimental trials demonstrated that increasing the air recirculation ratio enhances the ESI due to improved heat recovery and reduced exergy losses, while it reduces the EIP, indicating lower thermodynamic inefficiencies and less potential for further improvement. In contrast, lower recirculation ratios yielded lower ESI values and higher EIP, highlighting greater exergy destruction and larger optimization potential. Additionally, increased air temperatures and flow rates improved both indices. The results indicated that the neural network can predict all four outcomes with R2 > 0.97. Additionally, 0.013601 (using a 4–23–1 topology), 6.4137 × 10−6 (4–15–1 topology), 3.186 × 10−6 (4–30–1 topology), and 0.036108 (4–32–1 topology) were the mean squared error (MSE) values for predicting the EIP, ESI, UEE, and OEE, respectively. Hence, this study suggests that the ANNs approach could be an effective tool for analyzing thermal sustainability indicators in industrial convective drying processes.
{"title":"Exergetic sustainability assessment of a semi-industrial convective dryer employing waste heat recovery for drying wood chips: A BPANN-based approach","authors":"Saman Zohrabi , Seyed Sadegh Seiiedlou , Iman Golpour , Jochen Mellmann , Barbara Sturm , José Daniel Marcos , Ana M. Blanco-Marigorta , Fardad Didaran , Mark Lefsrud","doi":"10.1016/j.tsep.2026.104501","DOIUrl":"10.1016/j.tsep.2026.104501","url":null,"abstract":"<div><div>This study investigates the exergy-based performance and sustainability of a semi-industrial convective dryer equipped with a waste heat recovery unit for drying poplar wood chips. Four key exergy-related indicators, namely exergetic improvement potential (EIP), exergetic sustainability index (ESI), universal exergetic efficiency (UEE), and overall exergetic efficiency (OEE) were examined and then predicted using a feedforward backpropagation multilayer perceptron neural network (FFBP-MLPNN) with the Levenberg-Marquardt (LM) learning algorithm and a single hidden layer. The network evaluated different numbers of neurons in the hidden layer and utilized tansig and purelin activation functions in the hidden and output layers, respectively. Experimental trials demonstrated that increasing the air recirculation ratio enhances the ESI due to improved heat recovery and reduced exergy losses, while it reduces the EIP, indicating lower thermodynamic inefficiencies and less potential for further improvement. In contrast, lower recirculation ratios yielded lower ESI values and higher EIP, highlighting greater exergy destruction and larger optimization potential. Additionally, increased air temperatures and flow rates improved both indices. The results indicated that the neural network can predict all four outcomes with R<sup>2</sup> > 0.97. Additionally, 0.013601 (using a 4–23–1 topology), 6.4137 × 10<sup>−6</sup> (4–15–1 topology), 3.186 × 10<sup>−6</sup> (4–30–1 topology), and 0.036108 (4–32–1 topology) were the mean squared error (MSE) values for predicting the EIP, ESI, UEE, and OEE, respectively. Hence, this study suggests that the ANNs approach could be an effective tool for analyzing thermal sustainability indicators in industrial convective drying processes.</div></div>","PeriodicalId":23062,"journal":{"name":"Thermal Science and Engineering Progress","volume":"70 ","pages":"Article 104501"},"PeriodicalIF":5.4,"publicationDate":"2026-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145980494","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2026-01-08DOI: 10.1016/j.tsep.2026.104497
Zhongxin Liu, Xuan Zhang, Long Zhang, Zekang Zhen, Keke Shao, Mengjie Song
Air injection into the water beneath ice generates bubbles that entrain warm water to impact the ice, which is a simple and effective method of de-icing. The submergence depth of the nozzle used to release the bubbles affects the ice melting process. Experiments are carried out in the range of submergence depths from 7.5 to 18 cm to analyze the ice morphology, bubble behavior, and heat transfer characteristics. The results show that the increase of the submergence depth causes the bottom ice-water interface profile to become flat and wide from tall and narrow. The melting rate in the height direction increases by 15.4 % when the submergence depth increases from 7.5 to 18 cm. A larger submergence depth yields a larger radial range of ice-water interface depression, which results in a larger maximum bubble contact area with ice during melting. The heat transfer coefficient increases with the increase of the submergence depth due to the decreasing gas holdup and the increasing flow rate of entrained water. A correction method to predict the heat transfer coefficients at different submergence depths is proposed, and the calculated data match well with the experimental data, with a deviation of less than 5 %. The results of this study are expected to be helpful for a more in-depth understanding of the ice melting process under a bubbly flow and provide a reference for the practical engineering application of bubble ice melting technology.
{"title":"Influence of nozzle submergence depth on the ice melting dynamics and heat transfer characteristics in controlled underwater bubbly flows","authors":"Zhongxin Liu, Xuan Zhang, Long Zhang, Zekang Zhen, Keke Shao, Mengjie Song","doi":"10.1016/j.tsep.2026.104497","DOIUrl":"10.1016/j.tsep.2026.104497","url":null,"abstract":"<div><div>Air injection into the water beneath ice generates bubbles that entrain warm water to impact the ice, which is a simple and effective method of de-icing. The submergence depth of the nozzle used to release the bubbles affects the ice melting process. Experiments are carried out in the range of submergence depths from 7.5 to 18 cm to analyze the ice morphology, bubble behavior, and heat transfer characteristics. The results show that the increase of the submergence depth causes the bottom ice-water interface profile to become flat and wide from tall and narrow. The melting rate in the height direction increases by 15.4 % when the submergence depth increases from 7.5 to 18 cm. A larger submergence depth yields a larger radial range of ice-water interface depression, which results in a larger maximum bubble contact area with ice during melting. The heat transfer coefficient increases with the increase of the submergence depth due to the decreasing gas holdup and the increasing flow rate of entrained water. A correction method to predict the heat transfer coefficients at different submergence depths is proposed, and the calculated data match well with the experimental data, with a deviation of less than 5 %. The results of this study are expected to be helpful for a more in-depth understanding of the ice melting process under a bubbly flow and provide a reference for the practical engineering application of bubble ice melting technology.</div></div>","PeriodicalId":23062,"journal":{"name":"Thermal Science and Engineering Progress","volume":"70 ","pages":"Article 104497"},"PeriodicalIF":5.4,"publicationDate":"2026-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145980641","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2026-01-08DOI: 10.1016/j.tsep.2025.104473
Lei Shi , Guanghui Wei , Chicheng He , Jiajun Chen , Ruibin Ning , Zhenghua Rao , Tian Zhou , Hongwei Li
Phase change materials (PCMs) have been given extensive attention due to their wide application in fields including energy storage, thermal management, and building energy conservation. This study systematically examines PCMs, highlighting their classification by composition, phase transition type, and operating temperature range. It then discusses the analytical and numerical methods used for solving phase change processes. The assumptions and limitations of analytical methods such as the Neumann method, moving heat source method, and Paterson method are emphasized. The ability of numerical methods, including the frontier tracking method and fixed grid method, to handle complex geometries and interface evolution is analyzed in detail. Subsequently, a comparison is made of the accuracy, robustness, and versatility of computational heat transfer (CHT) methods such as the finite difference method (FDM), finite volume method (FVM), and finite element method (FEM). The applicability, advantages, and disadvantages of each method in different application scenarios are also analyzed. Unlike prior reviews that primarily focused on PCM applications, this study fills a critical gap by providing a comparative and mechanism-oriented evaluation of analytical and numerical modeling approaches for phase-change heat transfer. Finally, the review concludes by discussing future development directions, highlighting the integration of high-fidelity simulation, data-driven models, and multi-scale methods to address increasingly complex phase change systems. The review serves as a practical reference for engineers and researchers, supporting the selection and deployment of suitable modeling tools for PCM-based systems used in energy storage, thermal management, and building energy efficiency.
{"title":"Simulation methods for phase change heat transfer: A review","authors":"Lei Shi , Guanghui Wei , Chicheng He , Jiajun Chen , Ruibin Ning , Zhenghua Rao , Tian Zhou , Hongwei Li","doi":"10.1016/j.tsep.2025.104473","DOIUrl":"10.1016/j.tsep.2025.104473","url":null,"abstract":"<div><div>Phase change materials (PCMs) have been given extensive attention due to their wide application in fields including energy storage, thermal management, and building energy conservation. This study systematically examines PCMs, highlighting their classification by composition, phase transition type, and operating temperature range. It then discusses the analytical and numerical methods used for solving phase change processes. The assumptions and limitations of analytical methods such as the Neumann method, moving heat source method, and Paterson method are emphasized. The ability of numerical methods, including the frontier tracking method and fixed grid method, to handle complex geometries and interface evolution is analyzed in detail. Subsequently, a comparison is made of the accuracy, robustness, and versatility of computational heat transfer (CHT) methods such as the finite difference method (FDM), finite volume method (FVM), and finite element method (FEM). The applicability, advantages, and disadvantages of each method in different application scenarios are also analyzed. Unlike prior reviews that primarily focused on PCM applications, this study fills a critical gap by providing a comparative and mechanism-oriented evaluation of analytical and numerical modeling approaches for phase-change heat transfer. Finally, the review concludes by discussing future development directions, highlighting the integration of high-fidelity simulation, data-driven models, and multi-scale methods to address increasingly complex phase change systems. The review serves as a practical reference for engineers and researchers, supporting the selection and deployment of suitable modeling tools for PCM-based systems used in energy storage, thermal management, and building energy efficiency.</div></div>","PeriodicalId":23062,"journal":{"name":"Thermal Science and Engineering Progress","volume":"70 ","pages":"Article 104473"},"PeriodicalIF":5.4,"publicationDate":"2026-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145980639","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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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