Pub Date : 2024-11-23DOI: 10.1016/j.energy.2024.133827
Martin Hjelmeland, Jonas Kristiansen Nøland
This comment aims to provide a critical analysis of the article entitled ”Uncertainties in estimating production costs of future nuclear technologies: A model-based analysis of small modular reactors” [Energy 281 (2023) 128204], which presents a model-based analysis to estimate the future costs of small modular reactors (SMRs). Their work is timely, containing models from production theory that could be used to predict the future cost of nuclear technologies. Nonetheless, it is unfortunate that the article contains a series of unjustified assumptions that severely inflate the results.
{"title":"Comments on “Uncertainties in estimating production costs of future nuclear technologies: A model-based analysis of small modular reactors” [Energy 281 (2023) 128204]","authors":"Martin Hjelmeland, Jonas Kristiansen Nøland","doi":"10.1016/j.energy.2024.133827","DOIUrl":"10.1016/j.energy.2024.133827","url":null,"abstract":"<div><div>This comment aims to provide a critical analysis of the article entitled ”Uncertainties in estimating production costs of future nuclear technologies: A model-based analysis of small modular reactors” [Energy 281 (2023) 128204], which presents a model-based analysis to estimate the future costs of small modular reactors (SMRs). Their work is timely, containing models from production theory that could be used to predict the future cost of nuclear technologies. Nonetheless, it is unfortunate that the article contains a series of unjustified assumptions that severely inflate the results.</div></div>","PeriodicalId":11647,"journal":{"name":"Energy","volume":"313 ","pages":"Article 133827"},"PeriodicalIF":9.0,"publicationDate":"2024-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142722107","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}
Pub Date : 2024-11-23DOI: 10.1016/j.energy.2024.133949
Yang Cai , Zheng-Yu Shu , Jian-Wei He , Yong-Cai Li , Yuan-Da Cheng , Kai-Liang Huang , Fu-Yun Zhao
<div><div>In the face of escalating environmental challenges and dwindling fossil fuel reserves, the transition to renewable and sustainable energy sources has become a paramount global objective, which has led to a surge in research and application of renewable energy sources. Among them, solar energy utilization has been placed at the forefront of energy conservation revolution owing to its significant advantages in terms of sustainability and environmentally-friendliness. Solar-induced ventilation technology (SVT) is a typical way to integrate clean energy with buildings, considerably enhancing solar energy utilization efficiency while achieving building energy conservation and indoor thermal environment regulation. However, summaries as comprehensive as possible for SVT's application in envelopes are ambiguous in the current academia. Different analytical models, parameters and evaluation indicators need to be reviewed to describe the energy flow transfer and the impact on indoor thermal environment, which makes it indispensable to carry out an comprehensive overview for the latest investigation progress. This article endeavors to carry out an elaborate review of the theoretical analysis and constructive application of SVT from an energy utilization and building thermal environment perspective. Firstly, various types of SVT envelopes are classified simultaneously according to development and innovation in solar energy utilization. Furthermore, four different analytical models, namely, heat transfer model, thermal resistance network model, pressure balance model as well as computational fluid dynamics model, have been summarized, which would be helpful to analyze the thermal performance. Through literature review, this article discusses the impact of numerous parameters on system performance, especially the ventilation effect and thermal environment in buildings, from aspects of geometry, material properties and environmental conditions. In addition, a comprehensive collection of the important evaluation indicators based on the energy, thermal comfort and economic evaluations has been introduced to evaluate the thermal performance and indoor environment regulation capability of SVT envelopes, which provided a clear reference on developing and application SVT for high energy efficiency design towards carbon-neutral building envelopes. Finally, the challenges and potential are pointed out in terms of performance enhancement and the expansion of application scenarios. The results of the survey indicated that due to the development of novel technologies and materials, SVT holds great advantages in mitigating building energy consumption and regulating thermal environment, which shows a diversified development trend and promotes the process of global sustainable development. The review of the current SVT building envelope not only clarified the high feasibility of SVT in promoting passive building ventilation, energy saving and enhancing the level o
{"title":"A state-of-the-art review of solar-induced ventilation technology for built environment regulation: Classification, modeling, evaluation, potential and challenges","authors":"Yang Cai , Zheng-Yu Shu , Jian-Wei He , Yong-Cai Li , Yuan-Da Cheng , Kai-Liang Huang , Fu-Yun Zhao","doi":"10.1016/j.energy.2024.133949","DOIUrl":"10.1016/j.energy.2024.133949","url":null,"abstract":"<div><div>In the face of escalating environmental challenges and dwindling fossil fuel reserves, the transition to renewable and sustainable energy sources has become a paramount global objective, which has led to a surge in research and application of renewable energy sources. Among them, solar energy utilization has been placed at the forefront of energy conservation revolution owing to its significant advantages in terms of sustainability and environmentally-friendliness. Solar-induced ventilation technology (SVT) is a typical way to integrate clean energy with buildings, considerably enhancing solar energy utilization efficiency while achieving building energy conservation and indoor thermal environment regulation. However, summaries as comprehensive as possible for SVT's application in envelopes are ambiguous in the current academia. Different analytical models, parameters and evaluation indicators need to be reviewed to describe the energy flow transfer and the impact on indoor thermal environment, which makes it indispensable to carry out an comprehensive overview for the latest investigation progress. This article endeavors to carry out an elaborate review of the theoretical analysis and constructive application of SVT from an energy utilization and building thermal environment perspective. Firstly, various types of SVT envelopes are classified simultaneously according to development and innovation in solar energy utilization. Furthermore, four different analytical models, namely, heat transfer model, thermal resistance network model, pressure balance model as well as computational fluid dynamics model, have been summarized, which would be helpful to analyze the thermal performance. Through literature review, this article discusses the impact of numerous parameters on system performance, especially the ventilation effect and thermal environment in buildings, from aspects of geometry, material properties and environmental conditions. In addition, a comprehensive collection of the important evaluation indicators based on the energy, thermal comfort and economic evaluations has been introduced to evaluate the thermal performance and indoor environment regulation capability of SVT envelopes, which provided a clear reference on developing and application SVT for high energy efficiency design towards carbon-neutral building envelopes. Finally, the challenges and potential are pointed out in terms of performance enhancement and the expansion of application scenarios. The results of the survey indicated that due to the development of novel technologies and materials, SVT holds great advantages in mitigating building energy consumption and regulating thermal environment, which shows a diversified development trend and promotes the process of global sustainable development. The review of the current SVT building envelope not only clarified the high feasibility of SVT in promoting passive building ventilation, energy saving and enhancing the level o","PeriodicalId":11647,"journal":{"name":"Energy","volume":"313 ","pages":"Article 133949"},"PeriodicalIF":9.0,"publicationDate":"2024-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142757393","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}
Pub Date : 2024-11-16DOI: 10.1016/j.energy.2024.133808
Mohammad Mustafa Ghafurian , Brian Elmegaard , Peter Weinberger , Ahmad Arabkoohsar
This paper aims to review recent advancements in the utilization, storage, and integration of salt hydrates (SHs) in renewable energy (RE) systems. Initially, the latest review articles on applications of SHs in the energy sector are discussed. Then, various categories of SHs are extensively studied, emphasizing their thermochemical and thermophysical properties. SHs utilized in RE technologies across different temperature ranges alongside limitations like toxicity, corrosion, and cost are reviewed, and the most effective SHs in terms of chemical energy density, and cost-effectiveness at various temperatures are identified. Eventually, challenges, research gaps, and potential future work regarding these SHs are discussed. The study concludes that the most frequently used salts in sustainable energy systems include, but are not limited to, LiOH (0→-1) for temperatures above 150 °C, LiNO2 (1 → 0) for 80 °C to 150 °C, LiOH (1 → 0) for 40 °C to 80 °C, LiCl (2 → 1) for 10 °C to 40 °C, and LiBr (2 → 1) for temperatures below 10 °C. Moreover, the study highlights a significant group of SHs with diverse operating temperatures and high energy densities that have not yet been sufficiently investigated. Economically, the most promising salts are identified as Na2CO3, MgCl2,MgSO4 and Ca(OH)2 due to their low cost per unit of chemical energy.
{"title":"Salt hydrates in renewable energy systems: A thorough review","authors":"Mohammad Mustafa Ghafurian , Brian Elmegaard , Peter Weinberger , Ahmad Arabkoohsar","doi":"10.1016/j.energy.2024.133808","DOIUrl":"10.1016/j.energy.2024.133808","url":null,"abstract":"<div><div>This paper aims to review recent advancements in the utilization, storage, and integration of salt hydrates (SHs) in renewable energy (RE) systems. Initially, the latest review articles on applications of SHs in the energy sector are discussed. Then, various categories of SHs are extensively studied, emphasizing their thermochemical and thermophysical properties. SHs utilized in RE technologies across different temperature ranges alongside limitations like toxicity, corrosion, and cost are reviewed, and the most effective SHs in terms of chemical energy density, and cost-effectiveness at various temperatures are identified. Eventually, challenges, research gaps, and potential future work regarding these SHs are discussed. The study concludes that the most frequently used salts in sustainable energy systems include, but are not limited to, LiOH (0→-1) for temperatures above 150 °C, LiNO<sub>2</sub> (1 → 0) for 80 °C to 150 °C, LiOH (1 → 0) for 40 °C to 80 °C, LiCl (2 → 1) for 10 °C to 40 °C, and LiBr (2 → 1) for temperatures below 10 °C. Moreover, the study highlights a significant group of SHs with diverse operating temperatures and high energy densities that have not yet been sufficiently investigated. Economically, the most promising salts are identified as Na<sub>2</sub>CO<sub>3</sub>, MgCl<sub>2</sub>,MgSO<sub>4</sub> and Ca(OH)<sub>2</sub> due to their low cost per unit of chemical energy.</div></div>","PeriodicalId":11647,"journal":{"name":"Energy","volume":"313 ","pages":"Article 133808"},"PeriodicalIF":9.0,"publicationDate":"2024-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142746503","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-16DOI: 10.1016/j.energy.2024.133847
Ruzhu Wang, Hongzhi Yan, Di Wu, Jiatong Jiang, Yixiu Dong
High-temperature heat pumps (HTHPs) provide a promising approach to reducing CO2 emissions in industrial heating applications. However, developing large-scale, high-temperature-output, and large temperature-lift heat pumps that utilize low-GWP refrigerants remains a challenge. Natural working fluids, particularly water, show potential due to their exceptional thermodynamic properties and environmental friendliness. Our findings indicate that by employing water as a refrigerant, high-temperature heat pumps can achieve a significant temperature lift of up to 100 °C while maintaining a satisfactory coefficient of performance (COP). Additionally, these systems demonstrate high flexibility, enabling them to operate as closed-cycles, hybrid closed and open cycles, or hybrid vapor compression and absorption systems. Furthermore, we identify feasible matching strategies for industrial high-temperature heat pumps, focusing on working fluids, components, and cycle structures, with variables such as compressor type, heating temperature, and capacity. Through this research, we highlight the unique performance advantages of water across a 100 °C temperature range and propose detailed design sketches centered on water, capable of achieving large temperature lifts and high-temperature outputs. These include compression cycles, absorption cycles, and mechanical vapor compression cycles, with particular attention to closed and open cycle combinations. Moreover, we emphasize the research gap in current industrial heat pump technologies, providing a forward-looking technological perspective on heat pumps as a key component in further industrial decarbonization.
高温热泵（HTHPs）为减少工业加热应用中的二氧化碳排放提供了一种前景广阔的方法。然而，开发使用低全球升温潜能值制冷剂的大规模、高温输出和大温升热泵仍然是一项挑战。天然工作流体，尤其是水，因其卓越的热力学特性和环境友好性而显示出潜力。我们的研究结果表明，通过使用水作为制冷剂，高温热泵可以在保持令人满意的性能系数（COP）的同时，实现高达 100 °C 的大幅温度提升。此外，这些系统还具有很高的灵活性，可以作为闭式循环、闭式和开式混合循环或蒸汽压缩和吸收式混合系统运行。此外，我们还确定了工业高温热泵的可行匹配策略，重点关注工作流体、组件和循环结构，以及压缩机类型、加热温度和容量等变量。通过这项研究，我们强调了水在 100 °C 温度范围内的独特性能优势，并提出了以水为中心的详细设计草图，能够实现较大的温度提升和高温输出。其中包括压缩循环、吸收循环和机械蒸汽压缩循环，并特别关注封闭循环和开放循环的组合。此外，我们还强调了当前工业热泵技术的研究空白，为热泵作为进一步工业脱碳的关键组成部分提供了前瞻性的技术视角。
{"title":"High temperature heat pumps for industrial heating processes using water as refrigerant","authors":"Ruzhu Wang, Hongzhi Yan, Di Wu, Jiatong Jiang, Yixiu Dong","doi":"10.1016/j.energy.2024.133847","DOIUrl":"10.1016/j.energy.2024.133847","url":null,"abstract":"<div><div>High-temperature heat pumps (HTHPs) provide a promising approach to reducing CO<sub>2</sub> emissions in industrial heating applications. However, developing large-scale, high-temperature-output, and large temperature-lift heat pumps that utilize low-GWP refrigerants remains a challenge. Natural working fluids, particularly water, show potential due to their exceptional thermodynamic properties and environmental friendliness. Our findings indicate that by employing water as a refrigerant, high-temperature heat pumps can achieve a significant temperature lift of up to 100 °C while maintaining a satisfactory coefficient of performance (COP). Additionally, these systems demonstrate high flexibility, enabling them to operate as closed-cycles, hybrid closed and open cycles, or hybrid vapor compression and absorption systems. Furthermore, we identify feasible matching strategies for industrial high-temperature heat pumps, focusing on working fluids, components, and cycle structures, with variables such as compressor type, heating temperature, and capacity. Through this research, we highlight the unique performance advantages of water across a 100 °C temperature range and propose detailed design sketches centered on water, capable of achieving large temperature lifts and high-temperature outputs. These include compression cycles, absorption cycles, and mechanical vapor compression cycles, with particular attention to closed and open cycle combinations. Moreover, we emphasize the research gap in current industrial heat pump technologies, providing a forward-looking technological perspective on heat pumps as a key component in further industrial decarbonization.</div></div>","PeriodicalId":11647,"journal":{"name":"Energy","volume":"313 ","pages":"Article 133847"},"PeriodicalIF":9.0,"publicationDate":"2024-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142699114","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}
Pub Date : 2024-11-13DOI: 10.1016/j.energy.2024.133805
Boqiang Lin, Zhiwei Liu
The use of renewable energy sources (RES) is expected to increase, potentially leading to volatility in the power system. Therefore, flexible power is essential to address this challenge. In China, two viable options for providing flexible power are battery energy storage systems (BESS) and flexibility modification of coal power units. This study introduces a framework to evaluate the costs of power system flexibility under varying RES shares on an hourly basis, comparing flexible coal power and BESS across several scenarios. In the short term, flexible coal power proves to be more advantageous than BESS, but BESS shows greater promise in the long run. The study suggests that while coal power will continue to play a critical role in the near future, it should gradually be phased out by reducing its utilization hours. Meanwhile, BESS should receive greater focus for long-term energy strategy. This study underscores the importance of maintaining power system stability throughout the low-carbon transition and highlights the need to balance short-term and long-term strategies for flexible power.
{"title":"Assessment of flexible coal power and battery energy storage system in supporting renewable energy","authors":"Boqiang Lin, Zhiwei Liu","doi":"10.1016/j.energy.2024.133805","DOIUrl":"10.1016/j.energy.2024.133805","url":null,"abstract":"<div><div>The use of renewable energy sources (RES) is expected to increase, potentially leading to volatility in the power system. Therefore, flexible power is essential to address this challenge. In China, two viable options for providing flexible power are battery energy storage systems (BESS) and flexibility modification of coal power units. This study introduces a framework to evaluate the costs of power system flexibility under varying RES shares on an hourly basis, comparing flexible coal power and BESS across several scenarios. In the short term, flexible coal power proves to be more advantageous than BESS, but BESS shows greater promise in the long run. The study suggests that while coal power will continue to play a critical role in the near future, it should gradually be phased out by reducing its utilization hours. Meanwhile, BESS should receive greater focus for long-term energy strategy. This study underscores the importance of maintaining power system stability throughout the low-carbon transition and highlights the need to balance short-term and long-term strategies for flexible power.</div></div>","PeriodicalId":11647,"journal":{"name":"Energy","volume":"313 ","pages":"Article 133805"},"PeriodicalIF":9.0,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142661437","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}
Pub Date : 2024-11-13DOI: 10.1016/j.energy.2024.133818
Hang Lv , Qiong Wu , Hongbo Ren , Qifen Li , Weisheng Zhou
Extreme natural disasters are occurring with increasing frequency worldwide, posing unprecedented challenges to urban energy systems. In this study, an evolutionary game approach is employed to examine the interactive behavior among the grid, virtual power plant operators, and users, focusing on enhancing the resilience of urban energy systems. The impact of long-term power system development on the simulation outcomes has been examined. Key parameters in the game model are determined through numerical simulation. The evolutionary stabilization strategies of individual actors and the system have been analyzed holistically. According to the simulation results, as the benefit per unit of load restoration increases from 40 to 1000, all three parties increasingly prioritize resilience in their decision-making processes. Notably, when the benefit per unit of load restoration is 40, grid firms tend to disregard resilience. To enhance power system resilience, especially in the context of a high percentage of renewable energy generation, the utility grid should prioritize managing the integration of renewable energy into the grid. Moreover, there is a growing public interest in participating in dynamic demand response programs for incentives. In addition, within certain parameters, the objective of increasing renewable energy consumption may conflict with the aim of improving power system resilience. Virtual power plant operators are unlikely to introduce new renewable energy projects if the return is below 0.0325 Yuan/kWh. This study may offer strategic recommendations for enhancing long-term power system resilience, providing valuable insights for practical and realistic planning.
{"title":"Collaborative strategy towards a resilient urban energy system: Evidence from a tripartite evolutionary game model","authors":"Hang Lv , Qiong Wu , Hongbo Ren , Qifen Li , Weisheng Zhou","doi":"10.1016/j.energy.2024.133818","DOIUrl":"10.1016/j.energy.2024.133818","url":null,"abstract":"<div><div>Extreme natural disasters are occurring with increasing frequency worldwide, posing unprecedented challenges to urban energy systems. In this study, an evolutionary game approach is employed to examine the interactive behavior among the grid, virtual power plant operators, and users, focusing on enhancing the resilience of urban energy systems. The impact of long-term power system development on the simulation outcomes has been examined. Key parameters in the game model are determined through numerical simulation. The evolutionary stabilization strategies of individual actors and the system have been analyzed holistically. According to the simulation results, as the benefit per unit of load restoration increases from 40 to 1000, all three parties increasingly prioritize resilience in their decision-making processes. Notably, when the benefit per unit of load restoration is 40, grid firms tend to disregard resilience. To enhance power system resilience, especially in the context of a high percentage of renewable energy generation, the utility grid should prioritize managing the integration of renewable energy into the grid. Moreover, there is a growing public interest in participating in dynamic demand response programs for incentives. In addition, within certain parameters, the objective of increasing renewable energy consumption may conflict with the aim of improving power system resilience. Virtual power plant operators are unlikely to introduce new renewable energy projects if the return is below 0.0325 Yuan/kWh. This study may offer strategic recommendations for enhancing long-term power system resilience, providing valuable insights for practical and realistic planning.</div></div>","PeriodicalId":11647,"journal":{"name":"Energy","volume":"313 ","pages":"Article 133818"},"PeriodicalIF":9.0,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142661421","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}
Pub Date : 2024-11-13DOI: 10.1016/j.energy.2024.133814
Kun Su , Ziqu Ouyang , Shuyun Li , Qisi Chen , Hongshuai Wang , Hongliang Ding , Wenyu Wang
Under the strategic objectives of carbon peaking and carbon neutrality, increasingly stringent NOx emission standard was hard to meet in coal-fired boilers, and it was imperative to develop clean coal combustion technologies. As a novel combustion technology, purifying-combustion technology had good prospects in NOx emission reduction, and pulverized coal modification and modified fuel combustion occurred in purifying burner and down-fired combustor (DFC) respectively with this technology. The novelty of this study was associated with a first-time systematical analysis of the advantage of purifying burner in deep pulverized coal activation and the matching relationship of multistage combustion air in reduction region of DFC. Experiments were performed in 30 kW purifying-combustion test rig to investigate the two-stage modification characteristics of pulverized coal in purifying burner and the difference in influence of reducing intensity on combustion and NOx emission characteristics at different reduction region lengths and the influence of staged air distribution on them in DFC. Two-stage purifying burner demonstrated greater advantages in improving particle properties of pulverized coal compared to single-stage self-preheating burner: specific surface area, pore volume, pore diameter, density of carbon defect structure and fuel-N conversion rate increased from 19.01 m3/g, 29.15 mm3/g, 4.34 nm, 3.93 and 52.96 % to 34.39 m3/g, 42.49 mm3/g, 4.57 nm, 4.41 and 66.43 %, respectively. In DFC, increasing reducing intensity in reduction region or extending its length reduced NOx emission, albeit at the expense of combustion efficiency (η). Decreasing reducing intensity resulted in decrease of η difference and increase of NOx emission difference between different lengths. Staged air distribution in reduction region promoted clean and efficient combustion, and increasing staged air ratio to ∞ realized minimal NOx emission of 39.50 mg/m3 with η of 99.23 %.
{"title":"Exploration on deep pulverized coal activation and ultra-low NOx emission strategies with novel purifying-combustion technology","authors":"Kun Su , Ziqu Ouyang , Shuyun Li , Qisi Chen , Hongshuai Wang , Hongliang Ding , Wenyu Wang","doi":"10.1016/j.energy.2024.133814","DOIUrl":"10.1016/j.energy.2024.133814","url":null,"abstract":"<div><div>Under the strategic objectives of carbon peaking and carbon neutrality, increasingly stringent NO<sub><em>x</em></sub> emission standard was hard to meet in coal-fired boilers, and it was imperative to develop clean coal combustion technologies. As a novel combustion technology, purifying-combustion technology had good prospects in NO<sub><em>x</em></sub> emission reduction, and pulverized coal modification and modified fuel combustion occurred in purifying burner and down-fired combustor (DFC) respectively with this technology. The novelty of this study was associated with a first-time systematical analysis of the advantage of purifying burner in deep pulverized coal activation and the matching relationship of multistage combustion air in reduction region of DFC. Experiments were performed in 30 kW purifying-combustion test rig to investigate the two-stage modification characteristics of pulverized coal in purifying burner and the difference in influence of reducing intensity on combustion and NO<sub><em>x</em></sub> emission characteristics at different reduction region lengths and the influence of staged air distribution on them in DFC. Two-stage purifying burner demonstrated greater advantages in improving particle properties of pulverized coal compared to single-stage self-preheating burner: specific surface area, pore volume, pore diameter, density of carbon defect structure and fuel-N conversion rate increased from 19.01 m<sup>3</sup>/g, 29.15 mm<sup>3</sup>/g, 4.34 nm, 3.93 and 52.96 % to 34.39 m<sup>3</sup>/g, 42.49 mm<sup>3</sup>/g, 4.57 nm, 4.41 and 66.43 %, respectively. In DFC, increasing reducing intensity in reduction region or extending its length reduced NO<sub><em>x</em></sub> emission, albeit at the expense of combustion efficiency (<em>η</em>). Decreasing reducing intensity resulted in decrease of <em>η</em> difference and increase of NO<sub><em>x</em></sub> emission difference between different lengths. Staged air distribution in reduction region promoted clean and efficient combustion, and increasing staged air ratio to ∞ realized minimal NO<sub><em>x</em></sub> emission of 39.50 mg/m<sup>3</sup> with <em>η</em> of 99.23 %.</div></div>","PeriodicalId":11647,"journal":{"name":"Energy","volume":"313 ","pages":"Article 133814"},"PeriodicalIF":9.0,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142661335","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}
Pub Date : 2024-11-13DOI: 10.1016/j.energy.2024.133811
Yunge Zou , Yalian Yang , Yuxin Zhang , Changdong Liu
The powertrain configuration, sizing, and control are multi-dimensional intertwined. Synergy optimization of these three dimensions can yield the greatest benefits. However, the huge computational load limits its implementation. Especially for multi-modes and multi-gears (MMMG) transmissions. Thus, a more efficient optimization method with acceptable accuracy is urgently required. In this study, a near-global optimal method, called Hyper-Rapid Dynamic Programming (HR-DP), is proposed and discussed. The computation time is significantly reduced by optimization of candidate state and control domains, identification of optimal efficiency operating points, and parallel computation approaches. Subsequently, a thorough comparison of the HR-DP, Rapid-DP and DP methods was performed across various driving cycles. Compared to the DP algorithm, the computational efficiency is boosted by a factor of about 100,000, while the fuel consumption error is limited to 1.5 % in Real-world driving cycle (RWDC). Moreover, the HR-DP, in conjunction with particle swarm optimization (PSO), is employed for the first time to optimize essential sizing for MMMG configuration. The MMMG configuration with optimal sizing is demonstrated to be most energy-efficient, with 7.70%–10.6 % fuel-savings achieved, compared to the Toyota Prius. Therefore, HR-DP is well-suited for the design and optimization of HEV transmission configurations and sizing, significantly accelerating the development progress.
{"title":"Computationally efficient assessment of fuel economy of multi-modes and multi-gears hybrid electric vehicles: A hyper rapid dynamic programming approach","authors":"Yunge Zou , Yalian Yang , Yuxin Zhang , Changdong Liu","doi":"10.1016/j.energy.2024.133811","DOIUrl":"10.1016/j.energy.2024.133811","url":null,"abstract":"<div><div>The powertrain configuration, sizing, and control are multi-dimensional intertwined. Synergy optimization of these three dimensions can yield the greatest benefits. However, the huge computational load limits its implementation. Especially for <em>multi-modes and multi-gears</em> (MMMG) transmissions. Thus, a more efficient optimization method with acceptable accuracy is urgently required. In this study, a near-global optimal method, called <em>Hyper-Rapid Dynamic Programming</em> (HR-DP), is proposed and discussed. The computation time is significantly reduced by optimization of candidate state and control domains, identification of optimal efficiency operating points, and parallel computation approaches. Subsequently, a thorough comparison of the HR-DP, Rapid-DP and DP methods was performed across various driving cycles. Compared to the DP algorithm, the computational efficiency is boosted by a factor of about 100,000, while the fuel consumption error is limited to 1.5 % in Real-world driving cycle (RWDC). Moreover, the HR-DP, in conjunction with particle swarm optimization (PSO), is employed for the first time to optimize essential sizing for MMMG configuration. The MMMG configuration with optimal sizing is demonstrated to be most energy-efficient, with 7.70%–10.6 % fuel-savings achieved, compared to the Toyota Prius. Therefore, HR-DP is well-suited for the design and optimization of HEV transmission configurations and sizing, significantly accelerating the development progress.</div></div>","PeriodicalId":11647,"journal":{"name":"Energy","volume":"313 ","pages":"Article 133811"},"PeriodicalIF":9.0,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142661485","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}
Pub Date : 2024-11-13DOI: 10.1016/j.energy.2024.133782
Magdalena Skrzyniarz , Marcin Sajdak , Anna Biniek-Poskart , Andrzej Skibiński , Artur Maroszek , Paweł Niegodajew , Monika Zajemska
The paper presents some benefits that can be gained in the metallurgical industry from utilizing pyrolysis gas obtained from biomass and plastic waste, in particular in a pusher type reheating furnace. The typical fuel composition that normally involves a mixture of natural gas and coke oven gas was modified by introducing a 9–16 % share of pyrolysis gas. The materials used in the production of the pyrolysis gas were alder and pine chips, as well as polypropene waste. For all these materials, the contents of carbon, hydrogen, nitrogen, sulfur and oxygen were experimentally estimated on a test stand for solid fuel conversion in a stationary bed at the temperature of 600 °C. The design capacity of the furnace was 90 t/h and the installed power of the furnace was 72.3 MW. Based on data gained from the rolling mill of a steel mill located in Poland, analysis of the profitability of using pyrolysis gas for co-combustion with coke oven gas and natural gas in an industrial heating furnace was carried out. As a result, a significant benefit can be achieved, namely reduced production costs of the analyzed steel company by utilizing pyrolysis gas, leading to an increase in the attractiveness of the plant's products. Plastic waste and biomass are employed as energy sources in the suggested technology, therefore using them as feedstock for the pyrolysis reactor combined with the pusher type metallurgical reheating furnace is a potential proposal for the future.
本文介绍了在冶金工业中利用从生物质和塑料废料中获得的热解气体所能带来的一些益处，特别是在推杆式再加热炉中。典型的燃料成分通常包括天然气和焦炉煤气的混合物，通过引入 9-16% 的热解气体，对这种燃料成分进行了改良。用于生产热解气体的材料有桤木和松木屑，以及聚丙烯废料。所有这些材料的碳、氢、氮、硫和氧含量都是在 600 °C 固定床固体燃料转化试验台上通过实验估算出来的。该炉的设计产能为 90 吨/小时，装机功率为 72.3 兆瓦。根据从波兰一家钢厂的轧钢厂获得的数据，对在工业加热炉中使用热解气体与焦炉煤气和天然气共燃的盈利能力进行了分析。分析结果表明，利用热解气体可以获得巨大收益，即降低被分析钢铁公司的生产成本，从而提高工厂产品的吸引力。在建议的技术中，塑料废料和生物质被用作能源，因此，将它们用作热解反应器的原料并与推杆式冶金再加热炉相结合是未来的一个潜在建议。
{"title":"Economic benefits for the metallurgical industry from co-combusting pyrolysis gas from waste","authors":"Magdalena Skrzyniarz , Marcin Sajdak , Anna Biniek-Poskart , Andrzej Skibiński , Artur Maroszek , Paweł Niegodajew , Monika Zajemska","doi":"10.1016/j.energy.2024.133782","DOIUrl":"10.1016/j.energy.2024.133782","url":null,"abstract":"<div><div>The paper presents some benefits that can be gained in the metallurgical industry from utilizing pyrolysis gas obtained from biomass and plastic waste, in particular in a pusher type reheating furnace. The typical fuel composition that normally involves a mixture of natural gas and coke oven gas was modified by introducing a 9–16 % share of pyrolysis gas. The materials used in the production of the pyrolysis gas were alder and pine chips, as well as polypropene waste. For all these materials, the contents of carbon, hydrogen, nitrogen, sulfur and oxygen were experimentally estimated on a test stand for solid fuel conversion in a stationary bed at the temperature of 600 °C. The design capacity of the furnace was 90 t/h and the installed power of the furnace was 72.3 MW. Based on data gained from the rolling mill of a steel mill located in Poland, analysis of the profitability of using pyrolysis gas for co-combustion with coke oven gas and natural gas in an industrial heating furnace was carried out. As a result, a significant benefit can be achieved, namely reduced production costs of the analyzed steel company by utilizing pyrolysis gas, leading to an increase in the attractiveness of the plant's products. Plastic waste and biomass are employed as energy sources in the suggested technology, therefore using them as feedstock for the pyrolysis reactor combined with the pusher type metallurgical reheating furnace is a potential proposal for the future.</div></div>","PeriodicalId":11647,"journal":{"name":"Energy","volume":"313 ","pages":"Article 133782"},"PeriodicalIF":9.0,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142661429","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}
Pub Date : 2024-11-13DOI: 10.1016/j.energy.2024.133819
Edwin Alejandro Ramírez-Aguilar , David J. Sailor , Elizabeth A. Wentz
Understanding determinants of residential electricity consumption is crucial for urban sustainability efforts for planners and policy makers to develop targeted strategies to lower energy use, reduce greenhouse gas emissions, and to increase community resilience. This study presents a systematic approach to build an interpretable multivariate linear model, addressing challenges like outlier detection, multicollinearity, non-normality, and heteroscedasticity. Using 2019 summer residential electricity data for 426 census tracts in Phoenix and 30 variables, the approach involves (1) addressing multicollinearity and regression outliers through Variance Inflation Factor and studentized residual analysis, (2) comparing an automatic variable selection method with Ridge, Lasso, and Elastic Net regression, (3) evaluating the final model, and (4) interpreting variable effects. Critical findings reveal multicollinearity in land cover and racial variables, while 21 census tracts on the urban periphery exhibit outliers with unique features. Variable selection demonstrates the significance of household and building information in influencing residential electricity consumption. Household variables alone account for 84 % of electricity usage variation. Incorporating building information and land cover variables reduces errors by 35 % and 26 % respectively, emphasizing the significance of including household characteristics as predictors or control variables when modeling electricity consumption. A final model with 93 % explanatory power enables precise predictions.
{"title":"Household, sociodemographic, building and land cover factors affecting residential summer electricity consumption: A systematic statistical study in Phoenix, AZ","authors":"Edwin Alejandro Ramírez-Aguilar , David J. Sailor , Elizabeth A. Wentz","doi":"10.1016/j.energy.2024.133819","DOIUrl":"10.1016/j.energy.2024.133819","url":null,"abstract":"<div><div>Understanding determinants of residential electricity consumption is crucial for urban sustainability efforts for planners and policy makers to develop targeted strategies to lower energy use, reduce greenhouse gas emissions, and to increase community resilience. This study presents a systematic approach to build an interpretable multivariate linear model, addressing challenges like outlier detection, multicollinearity, non-normality, and heteroscedasticity. Using 2019 summer residential electricity data for 426 census tracts in Phoenix and 30 variables, the approach involves (1) addressing multicollinearity and regression outliers through Variance Inflation Factor and studentized residual analysis, (2) comparing an automatic variable selection method with Ridge, Lasso, and Elastic Net regression, (3) evaluating the final model, and (4) interpreting variable effects. Critical findings reveal multicollinearity in land cover and racial variables, while 21 census tracts on the urban periphery exhibit outliers with unique features. Variable selection demonstrates the significance of household and building information in influencing residential electricity consumption. Household variables alone account for 84 % of electricity usage variation. Incorporating building information and land cover variables reduces errors by 35 % and 26 % respectively, emphasizing the significance of including household characteristics as predictors or control variables when modeling electricity consumption. A final model with 93 % explanatory power enables precise predictions.</div></div>","PeriodicalId":11647,"journal":{"name":"Energy","volume":"313 ","pages":"Article 133819"},"PeriodicalIF":9.0,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142661424","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}
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