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Robust optimal model for rural integrated energy system incorporating biomass waste utilization and power-to-gas coupling unit considering deep learning-based air conditioning load personalized demand response

IF 9 1区工程技术 Q1 ENERGY & FUELS

Energy

Pub Date : 2025-03-07 DOI: 10.1016/j.energy.2025.135484

Zhenle Zhu , Zhiguo Qu , Jianqiang Gong , Jianjun Li , Hongtao Xu

To realize the low-carbon use of energy and reduce the pressure of energy supply. Based on the characteristics of abundant renewable resources in rural region, considering deep learning-based air conditioning load-personalized demand response (DL-AC-PDR), a robust optimal model for rural integrated energy system (RIES) is designed incorporating biomass waste utilization (BWU)- power to gas (P2G) coupling. Firstly, the study develops a biogas digester (BD) analytical model tailored to system optimization timescales. Subsequently, BD and biogas two-stage membrane purification (BTP) form BWU, and BWU-P2G coupling to alleviate the problem of economic carbon emission contradiction. After that, to alleviate the pressure on the peak power supply, based on deep learning, an air conditioning load-reducing mechanism considering personnel type is proposed. The case studies show: (1) The BD analytical model is improved to make it less complex to solve coupled with other units. (2) The RIES structure was improved by Carbon Capture (CC), Carbon Sequestration (CS) and BWU-P2G coupling units, which reduced the operating cost and carbon emission by 68.49 % and 19.37 %, respectively. (3) The implementation of DL-AC-PDR can reduce peak electrical load by 1.57 MW, and the operating cost and carbon emission of RIES are reduced by 0.36 % and 2.40 %, respectively.

{"title":"Robust optimal model for rural integrated energy system incorporating biomass waste utilization and power-to-gas coupling unit considering deep learning-based air conditioning load personalized demand response","authors":"Zhenle Zhu , Zhiguo Qu , Jianqiang Gong , Jianjun Li , Hongtao Xu","doi":"10.1016/j.energy.2025.135484","DOIUrl":"10.1016/j.energy.2025.135484","url":null,"abstract":"<div><div>To realize the low-carbon use of energy and reduce the pressure of energy supply. Based on the characteristics of abundant renewable resources in rural region, considering deep learning-based air conditioning load-personalized demand response (DL-AC-PDR), a robust optimal model for rural integrated energy system (RIES) is designed incorporating biomass waste utilization (BWU)- power to gas (P2G) coupling. Firstly, the study develops a biogas digester (BD) analytical model tailored to system optimization timescales. Subsequently, BD and biogas two-stage membrane purification (BTP) form BWU, and BWU-P2G coupling to alleviate the problem of economic carbon emission contradiction. After that, to alleviate the pressure on the peak power supply, based on deep learning, an air conditioning load-reducing mechanism considering personnel type is proposed. The case studies show: (1) The BD analytical model is improved to make it less complex to solve coupled with other units. (2) The RIES structure was improved by Carbon Capture (CC), Carbon Sequestration (CS) and BWU-P2G coupling units, which reduced the operating cost and carbon emission by 68.49 % and 19.37 %, respectively. (3) The implementation of DL-AC-PDR can reduce peak electrical load by 1.57 MW, and the operating cost and carbon emission of RIES are reduced by 0.36 % and 2.40 %, respectively.</div></div>","PeriodicalId":11647,"journal":{"name":"Energy","volume":"321 ","pages":"Article 135484"},"PeriodicalIF":9.0,"publicationDate":"2025-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143591817","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}

引用次数: 0

Design and operational performance evaluation of an integrated hydrothermal carbonization waste heat recovery and solar energy collection system

IF 9 1区工程技术 Q1 ENERGY & FUELS

Energy

Pub Date : 2025-03-07 DOI: 10.1016/j.energy.2025.135472

Ruikun Wang , Yukun Wu , Jiandong Jia , Jichao Wei , Lichao Ge , Yue Zhang , Peng Gao

Hydrothermal carbonization is a promising technology to convert sludge into solid fuel. However, a high energy consumption is required because the hydrothermal carbonization is operated at high temperature. Therefore, an integrated system of hydrothermal carbonization waste heat recovery and solar energy collection was proposed. This system recovered energy from the slurry product through a two-stage flash evaporation process, in which the steam from the first stage and the second stage were used for drying the semi-dry hydrochar and heating the raw sludge material, respectively. In addition, solar energy was collected to heat the sludge material. When 1 ton of sludge was treated under an hydrothermal carbonization temperature of 220 °C, 49.6 kg steam with energy of 127.31 MJ was recovered in the first stage flash evaporation, which could cover the heat required for drying the semi-dry hydrochar. Moreover, 147.3 kg of steam with energy of 426.97 MJ was recovered at the second stage flash evaporation, which was used to heat the raw sludge material, as well as the collected solar energy of 302.80 MJ. The exergy efficiency of the system was 54.84 %, and the exergy loss was caused mainly due to filtrate discharge, which accounted for 72.2 % of the total exergy loss.

{"title":"Design and operational performance evaluation of an integrated hydrothermal carbonization waste heat recovery and solar energy collection system","authors":"Ruikun Wang , Yukun Wu , Jiandong Jia , Jichao Wei , Lichao Ge , Yue Zhang , Peng Gao","doi":"10.1016/j.energy.2025.135472","DOIUrl":"10.1016/j.energy.2025.135472","url":null,"abstract":"<div><div>Hydrothermal carbonization is a promising technology to convert sludge into solid fuel. However, a high energy consumption is required because the hydrothermal carbonization is operated at high temperature. Therefore, an integrated system of hydrothermal carbonization waste heat recovery and solar energy collection was proposed. This system recovered energy from the slurry product through a two-stage flash evaporation process, in which the steam from the first stage and the second stage were used for drying the semi-dry hydrochar and heating the raw sludge material, respectively. In addition, solar energy was collected to heat the sludge material. When 1 ton of sludge was treated under an hydrothermal carbonization temperature of 220 °C, 49.6 kg steam with energy of 127.31 MJ was recovered in the first stage flash evaporation, which could cover the heat required for drying the semi-dry hydrochar. Moreover, 147.3 kg of steam with energy of 426.97 MJ was recovered at the second stage flash evaporation, which was used to heat the raw sludge material, as well as the collected solar energy of 302.80 MJ. The exergy efficiency of the system was 54.84 %, and the exergy loss was caused mainly due to filtrate discharge, which accounted for 72.2 % of the total exergy loss.</div></div>","PeriodicalId":11647,"journal":{"name":"Energy","volume":"321 ","pages":"Article 135472"},"PeriodicalIF":9.0,"publicationDate":"2025-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143592053","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}

引用次数: 0

Revisiting oil and tanker shipping markets: The role of geopolitical risk in shaping spillover dynamics

IF 9 1区工程技术 Q1 ENERGY & FUELS

Energy

Pub Date : 2025-03-07 DOI: 10.1016/j.energy.2025.135494

Shuiyang Chen , Siting Hao , Bin Meng , Yajing Zhang , Haibo Kuang

This study investigates the dynamic relationship between the crude oil and tanker shipping markets under geopolitical risk shocks, focusing on the differential impacts of threat-based and action-based geopolitical risks, as well as supply-demand disruptions. We employ the VAR-BEKK-GARCH model to capture spillover dynamics and their variations before and after geopolitical shocks, while the TVP-SV-VAR model provides a novel approach to visualize the intensity, direction, and duration of the effects of geopolitical risks over time. Our findings contribute to the understanding of altered market interactions under geopolitical risks by distinguishing between threat-based and action-based shocks, as well as analyzing the asymmetric impacts of supply-side and demand-side disruptions. Specifically, geopolitical risk is found to significantly amplify volatility spillovers from the BDTI to the crude oil market (+6.91 %), while reducing the reverse spillover (−14.92 %). Threat-based risks enhance bidirectional spillovers between crude oil and BCTI, while action-based risks dampen these spillovers. Furthermore, action-based risks have a more persistent effect, whereas threat-based risks induce a stronger, short-term response. Geopolitical risks impact correlations and hedge ratios, affecting diversification and portfolio allocation. These results emphasize the need to differentiate geopolitical risks, offering insights for energy policy, shipping resource allocation, and cross-market risk management.

{"title":"Revisiting oil and tanker shipping markets: The role of geopolitical risk in shaping spillover dynamics","authors":"Shuiyang Chen , Siting Hao , Bin Meng , Yajing Zhang , Haibo Kuang","doi":"10.1016/j.energy.2025.135494","DOIUrl":"10.1016/j.energy.2025.135494","url":null,"abstract":"<div><div>This study investigates the dynamic relationship between the crude oil and tanker shipping markets under geopolitical risk shocks, focusing on the differential impacts of threat-based and action-based geopolitical risks, as well as supply-demand disruptions. We employ the VAR-BEKK-GARCH model to capture spillover dynamics and their variations before and after geopolitical shocks, while the TVP-SV-VAR model provides a novel approach to visualize the intensity, direction, and duration of the effects of geopolitical risks over time. Our findings contribute to the understanding of altered market interactions under geopolitical risks by distinguishing between threat-based and action-based shocks, as well as analyzing the asymmetric impacts of supply-side and demand-side disruptions. Specifically, geopolitical risk is found to significantly amplify volatility spillovers from the BDTI to the crude oil market (+6.91 %), while reducing the reverse spillover (−14.92 %). Threat-based risks enhance bidirectional spillovers between crude oil and BCTI, while action-based risks dampen these spillovers. Furthermore, action-based risks have a more persistent effect, whereas threat-based risks induce a stronger, short-term response. Geopolitical risks impact correlations and hedge ratios, affecting diversification and portfolio allocation. These results emphasize the need to differentiate geopolitical risks, offering insights for energy policy, shipping resource allocation, and cross-market risk management.</div></div>","PeriodicalId":11647,"journal":{"name":"Energy","volume":"321 ","pages":"Article 135494"},"PeriodicalIF":9.0,"publicationDate":"2025-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143592054","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}

引用次数: 0

The effectiveness of renewable energy technology under the EKC hypothesis and the impact of fossil and nuclear energy investments on the UK's Ecological Footprint

IF 9 1区工程技术 Q1 ENERGY & FUELS

Energy

Pub Date : 2025-03-07 DOI: 10.1016/j.energy.2025.135351

Sefa Özbek , Mustafa Naimoğlu

This study addresses a critical gap in the literature by analyzing the environmental impact of renewable energy R&D effectiveness alongside other energy-related R&D investments, which has been largely neglected. Focusing on the UK from 1990 to 2022, the research examines the role of R&D in renewable energy, fossil fuels, nuclear energy, and GDP in driving the Ecological Footprint (EF). While previous studies on the Environmental Kuznets Curve (EKC) have rarely incorporated energy-related R&D, this study emphasizes that increasing renewable energy use, relative to R&D effectiveness, is key to understanding its environmental benefits. Using advanced econometric techniques such as Fourier Engle-Granger and Fourier ADL cointegration tests, FMOLS, CCR, and DOLS estimators, the findings reveal that enhanced renewable energy R&D significantly reduces EF, while fossil fuel and nuclear energy R&D investments also contribute to environmental mitigation. Additionally, GDP shows a long-term negative relationship with EF, aligning with the EKC hypothesis, though its short-term effect on environmental quality is limited. By highlighting the underexplored role of energy R&D, this study provides critical insights for policymakers seeking to balance economic growth with environmental sustainability.

{"title":"The effectiveness of renewable energy technology under the EKC hypothesis and the impact of fossil and nuclear energy investments on the UK's Ecological Footprint","authors":"Sefa Özbek , Mustafa Naimoğlu","doi":"10.1016/j.energy.2025.135351","DOIUrl":"10.1016/j.energy.2025.135351","url":null,"abstract":"<div><div>This study addresses a critical gap in the literature by analyzing the environmental impact of renewable energy R&D effectiveness alongside other energy-related R&D investments, which has been largely neglected. Focusing on the UK from 1990 to 2022, the research examines the role of R&D in renewable energy, fossil fuels, nuclear energy, and GDP in driving the Ecological Footprint (EF). While previous studies on the Environmental Kuznets Curve (EKC) have rarely incorporated energy-related R&D, this study emphasizes that increasing renewable energy use, relative to R&D effectiveness, is key to understanding its environmental benefits. Using advanced econometric techniques such as Fourier Engle-Granger and Fourier ADL cointegration tests, FMOLS, CCR, and DOLS estimators, the findings reveal that enhanced renewable energy R&D significantly reduces EF, while fossil fuel and nuclear energy R&D investments also contribute to environmental mitigation. Additionally, GDP shows a long-term negative relationship with EF, aligning with the EKC hypothesis, though its short-term effect on environmental quality is limited. By highlighting the underexplored role of energy R&D, this study provides critical insights for policymakers seeking to balance economic growth with environmental sustainability.</div></div>","PeriodicalId":11647,"journal":{"name":"Energy","volume":"322 ","pages":"Article 135351"},"PeriodicalIF":9.0,"publicationDate":"2025-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143621343","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}

引用次数: 0

Internal pricing driven dynamic aggregation of virtual power plant with energy storage systems

IF 9 1区工程技术 Q1 ENERGY & FUELS

Energy

Pub Date : 2025-03-07 DOI: 10.1016/j.energy.2025.135470

He Meng , Hongjie Jia , Tao Xu , Nikos Hatziargyriou , Wei Wei , Rujing Wang

Virtual power plant (VPP) has emerged as an energy service platform that can monitor, forecast, schedule and trade heterogeneous distributed flexible resources in an aggregated approach across various locations to enhance the flexibility and economics of power systems. One of the major goals of VPP is to maximize revenue for its resources that belong to different stakeholders. Therefore, it can be considered as a game with multiple players, various pricing strategies and payoffs. To incentivize the participation of distributed energy resources (DERs), including energy storage systems (ESSs), an internal pricing driven dynamic aggregation model of VPP is established based on a Stackelberg game. An improved artificial fish swarm algorithm (AFSA) and a mixed integer quadratic programming (MIQP) method are utilized to find the equilibrium solution of the model and to determine the internal transaction prices, dynamic aggregation and dispatching schemes of VPP. Two operation modes, VPP direct control ESS and photovoltaic (PV)-ESS joint operation, are compared to investigate the aggregation approaches and associated economics.

{"title":"Internal pricing driven dynamic aggregation of virtual power plant with energy storage systems","authors":"He Meng , Hongjie Jia , Tao Xu , Nikos Hatziargyriou , Wei Wei , Rujing Wang","doi":"10.1016/j.energy.2025.135470","DOIUrl":"10.1016/j.energy.2025.135470","url":null,"abstract":"<div><div>Virtual power plant (VPP) has emerged as an energy service platform that can monitor, forecast, schedule and trade heterogeneous distributed flexible resources in an aggregated approach across various locations to enhance the flexibility and economics of power systems. One of the major goals of VPP is to maximize revenue for its resources that belong to different stakeholders. Therefore, it can be considered as a game with multiple players, various pricing strategies and payoffs. To incentivize the participation of distributed energy resources (DERs), including energy storage systems (ESSs), an internal pricing driven dynamic aggregation model of VPP is established based on a Stackelberg game. An improved artificial fish swarm algorithm (AFSA) and a mixed integer quadratic programming (MIQP) method are utilized to find the equilibrium solution of the model and to determine the internal transaction prices, dynamic aggregation and dispatching schemes of VPP. Two operation modes, VPP direct control ESS and photovoltaic (PV)-ESS joint operation, are compared to investigate the aggregation approaches and associated economics.</div></div>","PeriodicalId":11647,"journal":{"name":"Energy","volume":"321 ","pages":"Article 135470"},"PeriodicalIF":9.0,"publicationDate":"2025-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143601195","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}

引用次数: 0

Nozzle spray-cooling coupled PEMFC stack radiator: Thermal-hydraulic performance and integrated correlations

IF 9 1区工程技术 Q1 ENERGY & FUELS

Energy

Pub Date : 2025-03-07 DOI: 10.1016/j.energy.2025.135517

M. Mohamed Souby , Rajendran Prabakaran , Sung Chul Kim

As the automotive industry shifts towards electrification to combat climate change, proton-exchange membrane fuel cell (PEMFC) stacks present a viable solution for heavy-duty trucks with extended ranges. This paper addresses the challenge of PEMFC cooling using the evaporative effect of exhaust water injected into a stack radiator via a nozzle. An experimental optimization of the thermal-hydraulic characteristics of a nozzle spray cooling-integrated stack radiator under diverse operating conditions was performed. The effect of the nozzle orientation and the impact of air velocity/temperature, coolant flowrate/temperature, and spray flowrate/temperature were investigated. The findings revealed that the effect of nozzle orientation on the performance decreased as the air velocity increased. Furthermore, the spray cooling performance was highly sensitive to changes in the air velocity and spray flow rate, whereas the coolant-side variables had a relatively low impact. The optimal thermal performance was obtained when the spray flowrate was set to 0.30 LPM, and the nozzle was oriented at 60°. Compared with the air-cooled radiator, the heat rejection improved by 167.7 %, whereas the air pressure drop increased by 124.1 % when applying the spray. Two novel empirical correlations were established to accurately predict the heat transfer enhancement and spray cooling efficiency with mean absolute errors of 5.3 % and 2.87 %, respectively. These results highlight the promising application of spray cooling in stack radiators for fuel-cell vehicles, and the correlations provide crucial guidance for the design of spray-cooled radiators for future electric vehicles.

{"title":"Nozzle spray-cooling coupled PEMFC stack radiator: Thermal-hydraulic performance and integrated correlations","authors":"M. Mohamed Souby , Rajendran Prabakaran , Sung Chul Kim","doi":"10.1016/j.energy.2025.135517","DOIUrl":"10.1016/j.energy.2025.135517","url":null,"abstract":"<div><div>As the automotive industry shifts towards electrification to combat climate change, proton-exchange membrane fuel cell (PEMFC) stacks present a viable solution for heavy-duty trucks with extended ranges. This paper addresses the challenge of PEMFC cooling using the evaporative effect of exhaust water injected into a stack radiator via a nozzle. An experimental optimization of the thermal-hydraulic characteristics of a nozzle spray cooling-integrated stack radiator under diverse operating conditions was performed. The effect of the nozzle orientation and the impact of air velocity/temperature, coolant flowrate/temperature, and spray flowrate/temperature were investigated. The findings revealed that the effect of nozzle orientation on the performance decreased as the air velocity increased. Furthermore, the spray cooling performance was highly sensitive to changes in the air velocity and spray flow rate, whereas the coolant-side variables had a relatively low impact. The optimal thermal performance was obtained when the spray flowrate was set to 0.30 LPM, and the nozzle was oriented at 60°. Compared with the air-cooled radiator, the heat rejection improved by 167.7 %, whereas the air pressure drop increased by 124.1 % when applying the spray. Two novel empirical correlations were established to accurately predict the heat transfer enhancement and spray cooling efficiency with mean absolute errors of 5.3 % and 2.87 %, respectively. These results highlight the promising application of spray cooling in stack radiators for fuel-cell vehicles, and the correlations provide crucial guidance for the design of spray-cooled radiators for future electric vehicles.</div></div>","PeriodicalId":11647,"journal":{"name":"Energy","volume":"321 ","pages":"Article 135517"},"PeriodicalIF":9.0,"publicationDate":"2025-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143591809","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}

引用次数: 0

Novel sealing design for high-speed coolant pumps: Impact on energy performance, axial thrust and flow field

IF 9 1区工程技术 Q1 ENERGY & FUELS

Energy

Pub Date : 2025-03-07 DOI: 10.1016/j.energy.2025.135511

Yandong Gu , Qiyuan Zhu , Junjie Bian , Qiliang Wang , Li Cheng

High-speed coolant pumps are critical devices for driving fluid circulation in the thermal management systems of various vehicles. However, the current pump sealing design is plagued by high energy losses and axial forces. Four sealing schemes were developed for the pump's front chamber. Case A uses an annular seal, Case B employs a labyrinth seal, Case C combines both, and Case D introduces a new labyrinth seal at the impeller entry. Numerical simulations were conducted, and the simulation results showed good agreement with the experimental data. The seals have a smaller impact on the head but significantly affect the efficiency, with Case D being 2.4 % more efficient. Besides, different seals generate varying front cavity pressure distributions and axial thrusts, with the axial force in Case D being the smallest, reduced by 25 %. Interference of backflow with the main flow at the impeller inlet differs across seal designs, with Case D minimizing interference and flow losses. Compared to the other seals, Case D significantly reduces the high-entropy production area at the impeller inlet. By analyzing energy performance, axial thrust, and flow field, Case D is identified as the optimal design, offering insights for improving vehicle thermal management systems.

{"title":"Novel sealing design for high-speed coolant pumps: Impact on energy performance, axial thrust and flow field","authors":"Yandong Gu , Qiyuan Zhu , Junjie Bian , Qiliang Wang , Li Cheng","doi":"10.1016/j.energy.2025.135511","DOIUrl":"10.1016/j.energy.2025.135511","url":null,"abstract":"<div><div>High-speed coolant pumps are critical devices for driving fluid circulation in the thermal management systems of various vehicles. However, the current pump sealing design is plagued by high energy losses and axial forces. Four sealing schemes were developed for the pump's front chamber. Case A uses an annular seal, Case B employs a labyrinth seal, Case C combines both, and Case D introduces a new labyrinth seal at the impeller entry. Numerical simulations were conducted, and the simulation results showed good agreement with the experimental data. The seals have a smaller impact on the head but significantly affect the efficiency, with Case D being 2.4 % more efficient. Besides, different seals generate varying front cavity pressure distributions and axial thrusts, with the axial force in Case D being the smallest, reduced by 25 %. Interference of backflow with the main flow at the impeller inlet differs across seal designs, with Case D minimizing interference and flow losses. Compared to the other seals, Case D significantly reduces the high-entropy production area at the impeller inlet. By analyzing energy performance, axial thrust, and flow field, Case D is identified as the optimal design, offering insights for improving vehicle thermal management systems.</div></div>","PeriodicalId":11647,"journal":{"name":"Energy","volume":"321 ","pages":"Article 135511"},"PeriodicalIF":9.0,"publicationDate":"2025-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143578275","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}

引用次数: 0

Effects of ammonia-coal co-pyrolysis on heterogeneous reduction of NO: Quantum chemical calculations and pyrolytic reduction experiments

IF 9 1区工程技术 Q1 ENERGY & FUELS

Energy

Pub Date : 2025-03-07 DOI: 10.1016/j.energy.2025.135496

Chuanjin Zhao, Hai Zhang, Kunmin Wu, Saibei Luo, Weidong Fan

Ammonia-coal co-combustion is a promising technology for reducing carbon dioxide emissions. However, the mechanism by which nitrogen-containing functional groups in the post-flame zone influence carbon during the co-combustion process is unclear. In this study, it is assumed that -NH₂ groups enhance nitrogen monoxide reduction by activating the char surface. Quantum chemical calculations, pyrolysis reduction experiments and X-ray Photoelectron Spectroscopy (XPS) experiments were combined to investigate -NH₂ modified char's reactivity. Quantum calculations show that the -NH₂ group activates the char surface, effectively enhancing the NO reduction on the char, with advantages in both thermodynamics and kinetics. Additionally, the calculations reveal that both -H and -NH (further pyrolysis products of -NH₂) can also lower the energy barrier for NO reduction on the char. The pyrolysis reduction experiment results show that increasing the co-pyrolysis temperature and ammonia blending ratio enhances the char's ability to reduce NO. Further XPS experiments reveal that the NO reduction rate exceeds the rate of decrease of char-NH₂, and this characteristic becomes more pronounced with increasing ammonia concentration during the co-pyrolysis stage. This confirms that the surface heterogeneous reduction of NO on char-NH₂ is an important pathway in the absence of -NH₂ involvement in the reaction.

{"title":"Effects of ammonia-coal co-pyrolysis on heterogeneous reduction of NO: Quantum chemical calculations and pyrolytic reduction experiments","authors":"Chuanjin Zhao, Hai Zhang, Kunmin Wu, Saibei Luo, Weidong Fan","doi":"10.1016/j.energy.2025.135496","DOIUrl":"10.1016/j.energy.2025.135496","url":null,"abstract":"<div><div>Ammonia-coal co-combustion is a promising technology for reducing carbon dioxide emissions. However, the mechanism by which nitrogen-containing functional groups in the post-flame zone influence carbon during the co-combustion process is unclear. In this study, it is assumed that -NH<sub>2</sub> groups enhance nitrogen monoxide reduction by activating the char surface. Quantum chemical calculations, pyrolysis reduction experiments and X-ray Photoelectron Spectroscopy (XPS) experiments were combined to investigate -NH<sub>2</sub> modified char's reactivity. Quantum calculations show that the -NH<sub>2</sub> group activates the char surface, effectively enhancing the NO reduction on the char, with advantages in both thermodynamics and kinetics. Additionally, the calculations reveal that both -H and -NH (further pyrolysis products of -NH<sub>2</sub>) can also lower the energy barrier for NO reduction on the char. The pyrolysis reduction experiment results show that increasing the co-pyrolysis temperature and ammonia blending ratio enhances the char's ability to reduce NO. Further XPS experiments reveal that the NO reduction rate exceeds the rate of decrease of char-NH<sub>2</sub>, and this characteristic becomes more pronounced with increasing ammonia concentration during the co-pyrolysis stage. This confirms that the surface heterogeneous reduction of NO on char-NH<sub>2</sub> is an important pathway in the absence of -NH<sub>2</sub> involvement in the reaction.</div></div>","PeriodicalId":11647,"journal":{"name":"Energy","volume":"321 ","pages":"Article 135496"},"PeriodicalIF":9.0,"publicationDate":"2025-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143601198","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}

引用次数: 0

Entropy and exergetic metrics for three spool turbofan engine with the aid of design parameters

IF 9 1区工程技术 Q1 ENERGY & FUELS

Energy

Pub Date : 2025-03-07 DOI: 10.1016/j.energy.2025.135508

Hakan Aygun , Onder Turan

With the development of aviation industry, gas turbine engines have kept pace with innovations retrofitted on their systems. Recently, on new generation civil aircraft, three-spool turbofan engines have started to be observed due to their higher efficiency compared to previous generation. In this context, parametric and thermodynamic analyses are performed for three spool turbofan engine (TSTE) by considering the effects of bypass ratio (BPR), ranging from 7 to 10 and combustor pressure ratio (CPR), varying from 0.9 to 0.98. According to parametric analysis, for constant airflow, net thrust of TSTE decreases from 345.63 kN to 288.89 kN due to increased BPR whereas it enhances from 301.4 kN to 308.2 kN with effect of elevated CPR. However, specific fuel consumption of TSTE favorably affects from both variables. Namely, BPR and CPR increase, it decreases from 9.64 g/kN.s to 8.39 g/kN.s and from 8.84 g/kN.s to 8.65 g/kN.s, respectively. As for entropy assessments, total entropy production of six turbomachinery components decreases from 56.45 kW/K and 41.87 kW/K due to higher BPR whereas it slightly increases from 45.2 kW/K to 46.39 kW/K with increment of CPR. Lastly, exergy efficiency of TSTE experiences enhancement from both variables. Namely, it changes from 34.03% to 39.11% owing to raised BPR and from 37.09% to 37.93% with increment of CPR. These outcomes underline that increasing BPR benefits lowering fuel consumption with sacrificing thrust performance whereas raising CPR has relatively less effect on fuel saving without performance loss. It is thought that this study helps in finding the optimum points for considered performance requirements.

{"title":"Entropy and exergetic metrics for three spool turbofan engine with the aid of design parameters","authors":"Hakan Aygun , Onder Turan","doi":"10.1016/j.energy.2025.135508","DOIUrl":"10.1016/j.energy.2025.135508","url":null,"abstract":"<div><div>With the development of aviation industry, gas turbine engines have kept pace with innovations retrofitted on their systems. Recently, on new generation civil aircraft, three-spool turbofan engines have started to be observed due to their higher efficiency compared to previous generation. In this context, parametric and thermodynamic analyses are performed for three spool turbofan engine (TSTE) by considering the effects of bypass ratio (BPR), ranging from 7 to 10 and combustor pressure ratio (CPR), varying from 0.9 to 0.98. According to parametric analysis, for constant airflow, net thrust of TSTE decreases from 345.63 kN to 288.89 kN due to increased BPR whereas it enhances from 301.4 kN to 308.2 kN with effect of elevated CPR. However, specific fuel consumption of TSTE favorably affects from both variables. Namely, BPR and CPR increase, it decreases from 9.64 g/kN.s to 8.39 g/kN.s and from 8.84 g/kN.s to 8.65 g/kN.s, respectively. As for entropy assessments, total entropy production of six turbomachinery components decreases from 56.45 kW/K and 41.87 kW/K due to higher BPR whereas it slightly increases from 45.2 kW/K to 46.39 kW/K with increment of CPR. Lastly, exergy efficiency of TSTE experiences enhancement from both variables. Namely, it changes from 34.03% to 39.11% owing to raised BPR and from 37.09% to 37.93% with increment of CPR. These outcomes underline that increasing BPR benefits lowering fuel consumption with sacrificing thrust performance whereas raising CPR has relatively less effect on fuel saving without performance loss. It is thought that this study helps in finding the optimum points for considered performance requirements.</div></div>","PeriodicalId":11647,"journal":{"name":"Energy","volume":"321 ","pages":"Article 135508"},"PeriodicalIF":9.0,"publicationDate":"2025-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143591788","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}

引用次数: 0

Improvement of low-temperature NH3-SCR performance of Cu-zeolite and vanadium catalysts through ozone injection

IF 9 1区工程技术 Q1 ENERGY & FUELS

Energy

Pub Date : 2025-03-07 DOI: 10.1016/j.energy.2025.135510

Yanghwa Kim , Ocktaeck Lim , Gyubaek Cho , Hongsuk Kim

Selective catalytic reduction (SCR), a widely used technology to mitigate NO_x emissions from diesel engines, faces the challenge of improving NO_x reduction efficiency at low temperatures. O₃ can improve the low-temperature NO_x reduction performance of SCR by oxidizing NO in exhaust gas to NO₂, a more reactive molecule. This study investigates the potential of O₃ assisted SCR reaction in real exhaust gas condition of diesel engine and compares the differences of two catalysts, Cu-zeolite and vanadium. The results show that NO_x reduction performance at low temperature can be improved by assisting O₃ in the both catalysts. The improvement of NO_x reduction performance was slightly better for the Cu-zeolite catalyst than for the vanadium catalyst. This is because Cu-zeolite catalysts have a larger NO₂ or HNO₃ adsorption capacity and stronger bonding strength than vanadium catalysts, undergoing better SCR reaction and forming more NH₄NO₃.

{"title":"Improvement of low-temperature NH3-SCR performance of Cu-zeolite and vanadium catalysts through ozone injection","authors":"Yanghwa Kim , Ocktaeck Lim , Gyubaek Cho , Hongsuk Kim","doi":"10.1016/j.energy.2025.135510","DOIUrl":"10.1016/j.energy.2025.135510","url":null,"abstract":"<div><div>Selective catalytic reduction (SCR), a widely used technology to mitigate NO<sub>x</sub> emissions from diesel engines, faces the challenge of improving NO<sub>x</sub> reduction efficiency at low temperatures. O<sub>3</sub> can improve the low-temperature NO<sub>x</sub> reduction performance of SCR by oxidizing NO in exhaust gas to NO<sub>2</sub>, a more reactive molecule. This study investigates the potential of O<sub>3</sub> assisted SCR reaction in real exhaust gas condition of diesel engine and compares the differences of two catalysts, Cu-zeolite and vanadium. The results show that NO<sub>x</sub> reduction performance at low temperature can be improved by assisting O<sub>3</sub> in the both catalysts. The improvement of NO<sub>x</sub> reduction performance was slightly better for the Cu-zeolite catalyst than for the vanadium catalyst. This is because Cu-zeolite catalysts have a larger NO<sub>2</sub> or HNO<sub>3</sub> adsorption capacity and stronger bonding strength than vanadium catalysts, undergoing better SCR reaction and forming more NH<sub>4</sub>NO<sub>3</sub>.</div></div>","PeriodicalId":11647,"journal":{"name":"Energy","volume":"322 ","pages":"Article 135510"},"PeriodicalIF":9.0,"publicationDate":"2025-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143610348","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}

引用次数: 0

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