As the critical component of a nuclear power plant (NPP), the reactor coolant pump (RCP) will suffer energy losses during operation, which can lead to a series of safety issues and adversely affect the efficiency and stability of the NPP. In this study, the SST k-ω turbulence model is utilized to simulate the internal flow field of an axial-flow reactor coolant pump (RCP) under operating conditions of 0.8QN to 1.2QN. Combined with entropy production theory, the distribution characteristics and hydraulic causes of energy loss within different regions of the RCP are revealed. The research findings are as follows: the total entropy production in the RCP first decreases and then increases during operation; with turbulent entropy production consistently accounting for over 70% of the total, and direct entropy production accounting for less than 10%. The impeller and annular casing are always the main components responsible for hydraulic losses within the pump. As the flow rate increases, the total entropy production in the impeller initially decreases and then increases, accounting for between 34.3% and 51% of the total; with energy losses mainly concentrated on the suction side of the impeller blades. The total entropy production in the annular casing gradually increases under operating conditions ranging from 0.8QN to 1.2QN, accounting for between 20.4% and 50.3% of the total. Rotor-stator interaction (RSI), backflow, and flow separation near the volute tongue are significant causes of energy losses within the annular casing. Optimizing the geometric parameters of the impeller and annular casing is an effective way to reduce flow losses in axial-flow RCPs. The research results can provide a reference for the development of optimization techniques for RCPs.
{"title":"Analysis of Energy Loss Characteristics in an Axial-Flow Reactor Coolant Pump Based on Entropy Production Theory","authors":"Zhong Li, Yanna Sun, Weifeng Gong, Dan Ni, Bo Gao","doi":"10.3390/en17143399","DOIUrl":"https://doi.org/10.3390/en17143399","url":null,"abstract":"As the critical component of a nuclear power plant (NPP), the reactor coolant pump (RCP) will suffer energy losses during operation, which can lead to a series of safety issues and adversely affect the efficiency and stability of the NPP. In this study, the SST k-ω turbulence model is utilized to simulate the internal flow field of an axial-flow reactor coolant pump (RCP) under operating conditions of 0.8QN to 1.2QN. Combined with entropy production theory, the distribution characteristics and hydraulic causes of energy loss within different regions of the RCP are revealed. The research findings are as follows: the total entropy production in the RCP first decreases and then increases during operation; with turbulent entropy production consistently accounting for over 70% of the total, and direct entropy production accounting for less than 10%. The impeller and annular casing are always the main components responsible for hydraulic losses within the pump. As the flow rate increases, the total entropy production in the impeller initially decreases and then increases, accounting for between 34.3% and 51% of the total; with energy losses mainly concentrated on the suction side of the impeller blades. The total entropy production in the annular casing gradually increases under operating conditions ranging from 0.8QN to 1.2QN, accounting for between 20.4% and 50.3% of the total. Rotor-stator interaction (RSI), backflow, and flow separation near the volute tongue are significant causes of energy losses within the annular casing. Optimizing the geometric parameters of the impeller and annular casing is an effective way to reduce flow losses in axial-flow RCPs. The research results can provide a reference for the development of optimization techniques for RCPs.","PeriodicalId":504870,"journal":{"name":"Energies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141657231","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sadia Tasnim Mowri, A. Barai, Sanghamitra Moharana, Aniruddha Gupta, James Marco
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{"title":"Correction: Tasnim Mowri et al. Assessing the Impact of First-Life Lithium-Ion Battery Degradation on Second-Life Performance. Energies 2024, 17, 501","authors":"Sadia Tasnim Mowri, A. Barai, Sanghamitra Moharana, Aniruddha Gupta, James Marco","doi":"10.3390/en17143402","DOIUrl":"https://doi.org/10.3390/en17143402","url":null,"abstract":"Error in Table [...]","PeriodicalId":504870,"journal":{"name":"Energies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141658276","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Kai Zhang, Xiangxiang Dong, Chaofeng Li, Yanling Zhao, Kun Liu
As the main contributor of carbon emissions, the low-carbon transition of the industrial sector is important for achieving the goal of carbon dioxide peaking. Hydrogen-enabled industrial energy systems (HIESs) are a promising way to achieve the low-carbon transition of industrial energy systems, since the hydrogen can be well coordinated with renewable energy sources and satisfy the high and continuous industrial energy demand. In this paper, the long-term capacity expansion planning problem of the HIES is formulated from the perspective of industrial parks, and the targets of carbon dioxide peaking and the gradual decommissioning of existing equipment are considered as constraints. The results show that the targets of carbon dioxide peaking before different years or with different emission reduction targets can be achieved through the developed method, while the economic performance is ensured to some extent. Meanwhile, the overall cost of the strategy based on purchasing emission allowance is three times more than the cost of the strategy obtained by the developed method, while the emissions of the two strategies are same. In addition, long-term carbon reduction policies and optimistic expectations for new energy technologies will help industrial parks build more new energy equipment for clean transformation.
{"title":"Capacity Expansion Planning of Hydrogen-Enabled Industrial Energy Systems for Carbon Dioxide Peaking","authors":"Kai Zhang, Xiangxiang Dong, Chaofeng Li, Yanling Zhao, Kun Liu","doi":"10.3390/en17143400","DOIUrl":"https://doi.org/10.3390/en17143400","url":null,"abstract":"As the main contributor of carbon emissions, the low-carbon transition of the industrial sector is important for achieving the goal of carbon dioxide peaking. Hydrogen-enabled industrial energy systems (HIESs) are a promising way to achieve the low-carbon transition of industrial energy systems, since the hydrogen can be well coordinated with renewable energy sources and satisfy the high and continuous industrial energy demand. In this paper, the long-term capacity expansion planning problem of the HIES is formulated from the perspective of industrial parks, and the targets of carbon dioxide peaking and the gradual decommissioning of existing equipment are considered as constraints. The results show that the targets of carbon dioxide peaking before different years or with different emission reduction targets can be achieved through the developed method, while the economic performance is ensured to some extent. Meanwhile, the overall cost of the strategy based on purchasing emission allowance is three times more than the cost of the strategy obtained by the developed method, while the emissions of the two strategies are same. In addition, long-term carbon reduction policies and optimistic expectations for new energy technologies will help industrial parks build more new energy equipment for clean transformation.","PeriodicalId":504870,"journal":{"name":"Energies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141658409","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Md Sahadat Hossain, Obste Therasme, Paul L. Crovella, Timothy A Volk
There are millions of older buildings in the colder climate regions of the world where envelope upgrades are needed to improve the indoor quality of buildings, reduce energy costs, and lower greenhouse gas (GHG) emissions. This study assessed the global warming potential (GWP) with and without accounting for CO2 uptake in trees (biogenic carbon) for 20- and 100-year timespans of an exterior insulation panel. The panels consisted of six different materials with three-ply cross-laminated timber (CLT) as its main component. The net GWP100-Uptake impact when explicitly accounting for biogenic CO2 uptake over a 100-year time period was 7.2 kgCO2-eq/m2 which was 92.7% lower than if it was not included (GWP100-Fossil of 98.7 kgCO2-eq/m2). Using a 20-year GWP increased the impact of the GWP fossil by 21.7% and the CO2 uptake scenario by 298%. The major contributor was the energy used for manufacturing panel’s materials (53%), with embodied carbon in bio-products primarily responsible for offsetting emissions. The findings will be helpful for policymakers in setting net-zero carbon emission goals for embodied and operational impacts of building materials.
{"title":"Assessing the Environmental Impact of Biobased Exterior Insulation Panel: A Focus on Carbon Uptake and Embodied Emissions","authors":"Md Sahadat Hossain, Obste Therasme, Paul L. Crovella, Timothy A Volk","doi":"10.3390/en17143406","DOIUrl":"https://doi.org/10.3390/en17143406","url":null,"abstract":"There are millions of older buildings in the colder climate regions of the world where envelope upgrades are needed to improve the indoor quality of buildings, reduce energy costs, and lower greenhouse gas (GHG) emissions. This study assessed the global warming potential (GWP) with and without accounting for CO2 uptake in trees (biogenic carbon) for 20- and 100-year timespans of an exterior insulation panel. The panels consisted of six different materials with three-ply cross-laminated timber (CLT) as its main component. The net GWP100-Uptake impact when explicitly accounting for biogenic CO2 uptake over a 100-year time period was 7.2 kgCO2-eq/m2 which was 92.7% lower than if it was not included (GWP100-Fossil of 98.7 kgCO2-eq/m2). Using a 20-year GWP increased the impact of the GWP fossil by 21.7% and the CO2 uptake scenario by 298%. The major contributor was the energy used for manufacturing panel’s materials (53%), with embodied carbon in bio-products primarily responsible for offsetting emissions. The findings will be helpful for policymakers in setting net-zero carbon emission goals for embodied and operational impacts of building materials.","PeriodicalId":504870,"journal":{"name":"Energies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141658515","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jiaping Tao, Siwei Meng, Dongxu Li, Lihao Liang, He Liu
The presence of highly developed micro-nano pores and poor pore connectivity constrains the development of shale oil. Given the rapid decline in oil production , enhanced oil recovery (EOR) technologies are necessary for shale oil development. The shale oil reservoirs in China are mainly continental and characterized by high heterogeneity, low overall maturity, and inferior crude oil quality. Therefore, it is more challenging to achieve a desirably high recovery factor. The Qingshankou Formation is a typical continental shale oil reservoir, with high clay content and well-developed bedding. This paper introduced high-precision non-destructive nuclear magnetic resonance technology to carry out a systematic and targeted study. The EOR performances and oil recovery factors related to different pore sizes were quantified to identify the most suitable method. The results show that surfactant, CH4, and CO2 can recover oil effectively in the first cycle. As the huff-and-puff process continues, the oil saturated in the shale gradually decreases, and the EOR performance of the surfactant and CH4 is considerably degraded. Meanwhile, CO2 can efficiently recover oil in small pores (<50 nm) and maintain good EOR performance in the second and third cycles. After four huff-and-puff cycles, the average oil recovery of CO2 is 38.22%, which is much higher than that of surfactant (29.82%) and CH4 (19.36%). CO2 is the most applicable medium of the three to enhance shale oil recovery in the Qingshankou Formation. Additionally, the injection pressure of surfactant increased the fastest in the injection process, showing a low flowability in nano-pores. Thus, in the actual shale oil formations, the swept volume of surfactant will be suppressed, and the actual EOR performance of the surfactant may be limited. The findings of this paper can provide theoretical support for the efficient development of continental shale oil reservoirs.
{"title":"Experimental Evaluation of Enhanced Oil Recovery in Shale Reservoirs Using Different Media","authors":"Jiaping Tao, Siwei Meng, Dongxu Li, Lihao Liang, He Liu","doi":"10.3390/en17143410","DOIUrl":"https://doi.org/10.3390/en17143410","url":null,"abstract":"The presence of highly developed micro-nano pores and poor pore connectivity constrains the development of shale oil. Given the rapid decline in oil production , enhanced oil recovery (EOR) technologies are necessary for shale oil development. The shale oil reservoirs in China are mainly continental and characterized by high heterogeneity, low overall maturity, and inferior crude oil quality. Therefore, it is more challenging to achieve a desirably high recovery factor. The Qingshankou Formation is a typical continental shale oil reservoir, with high clay content and well-developed bedding. This paper introduced high-precision non-destructive nuclear magnetic resonance technology to carry out a systematic and targeted study. The EOR performances and oil recovery factors related to different pore sizes were quantified to identify the most suitable method. The results show that surfactant, CH4, and CO2 can recover oil effectively in the first cycle. As the huff-and-puff process continues, the oil saturated in the shale gradually decreases, and the EOR performance of the surfactant and CH4 is considerably degraded. Meanwhile, CO2 can efficiently recover oil in small pores (<50 nm) and maintain good EOR performance in the second and third cycles. After four huff-and-puff cycles, the average oil recovery of CO2 is 38.22%, which is much higher than that of surfactant (29.82%) and CH4 (19.36%). CO2 is the most applicable medium of the three to enhance shale oil recovery in the Qingshankou Formation. Additionally, the injection pressure of surfactant increased the fastest in the injection process, showing a low flowability in nano-pores. Thus, in the actual shale oil formations, the swept volume of surfactant will be suppressed, and the actual EOR performance of the surfactant may be limited. The findings of this paper can provide theoretical support for the efficient development of continental shale oil reservoirs.","PeriodicalId":504870,"journal":{"name":"Energies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141655395","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Dan Shao, Liangyong Hu, Guoqing Zhang, Kaicheng Hu, Jiangyun Zhang, Jun Liu, Kang Peng, Liqin Jiang, Wenzhao Jiang, Yuliang Wen
The proton exchange membrane electrolysis cell (PEMEC) has attracted considerable attention for large-scale and efficient hydrogen production because of its high current density, high hydrogen purity and fast dynamic response. Flow field distributions and water and thermal management characteristics of a PEMEC are vital for electrolytic cell structure and the determination of operating condition. A three-dimensional, non-isothermal, electrochemical model of a PEMEC was established in this manuscript. The flow field distribution and water and thermal management of the PEMEC are discussed. The corresponding results showed that the pressure of the flow channel decreased diagonally from the inlet to the outlet, and the pressure and velocity distribution exhibited a downward opening shape of a parabola. At the same inlet flow rate, when the voltage was 1.6 V, the oxygen generation rate was 15.74 mol/(cm2·s), and when the voltage was 2.2 V, the oxygen generation rate was 332.05 mol/(cm2·s); due to the change in the oxygen production rate, the pressure difference at 2.2 V was 2.5 times than that at 1.6 V. When the stoichiometric number was less than two, the average temperature of the catalyst layer (CL) decreased rapidly with the increase in the water flow rate. When the voltage decreased to 2.1 V, the current density came to the highest value when the stoichiometric number was 0.7, then the current density decreased with an increase in the stoichiometric number. When stoichiometric numbers were higher than five, the surface temperature and current density remained basically stable with the increase in the water flow rate, and the water and thermal management and electrolysis characteristics performed better. The research results could optimize the water supply of electrolysis cells. According to the velocity distribution law of the flow field, the water and thermal management performance of the PEMEC could be estimated, further promoting safety and reliability.
质子交换膜电解池(PEMEC)因其高电流密度、高氢纯度和快速动态响应而在大规模高效制氢方面备受关注。质子交换膜电解槽的流场分布、水和热管理特性对于电解槽结构和确定运行条件至关重要。本手稿建立了 PEMEC 的三维、非等温、电化学模型。文中讨论了 PEMEC 的流场分布、水和热管理。相应的结果表明,流道的压力从入口到出口呈对角线下降,压力和速度分布呈现出抛物线向下开口的形状。在相同的入口流速下,当电压为 1.6 V 时,氧气产生率为 15.74 mol/(cm2-s),当电压为 2.2 V 时,氧气产生率为 332.05 mol/(cm2-s);由于氧气产生率的变化,2.2 V 时的压差是 1.6 V 时的 2.5 倍。当化学计量数小于 2 时,催化剂层(CL)的平均温度随着水流量的增加而迅速降低。当电压降低到 2.1 V 时,当化学计量数为 0.7 时,电流密度达到最高值,然后电流密度随着化学计量数的增加而降低。当化学计量数大于 5 时,随着水流量的增加,表面温度和电流密度基本保持稳定,水热管理和电解特性表现较好。研究结果可以优化电解槽的供水。根据流场的速度分布规律,可以估算 PEMEC 的水和热管理性能,进一步提高安全性和可靠性。
{"title":"Numerical Investigation of Flow Field Distributions and Water and Thermal Management for a Proton Exchange Membrane Electrolysis Cell","authors":"Dan Shao, Liangyong Hu, Guoqing Zhang, Kaicheng Hu, Jiangyun Zhang, Jun Liu, Kang Peng, Liqin Jiang, Wenzhao Jiang, Yuliang Wen","doi":"10.3390/en17143428","DOIUrl":"https://doi.org/10.3390/en17143428","url":null,"abstract":"The proton exchange membrane electrolysis cell (PEMEC) has attracted considerable attention for large-scale and efficient hydrogen production because of its high current density, high hydrogen purity and fast dynamic response. Flow field distributions and water and thermal management characteristics of a PEMEC are vital for electrolytic cell structure and the determination of operating condition. A three-dimensional, non-isothermal, electrochemical model of a PEMEC was established in this manuscript. The flow field distribution and water and thermal management of the PEMEC are discussed. The corresponding results showed that the pressure of the flow channel decreased diagonally from the inlet to the outlet, and the pressure and velocity distribution exhibited a downward opening shape of a parabola. At the same inlet flow rate, when the voltage was 1.6 V, the oxygen generation rate was 15.74 mol/(cm2·s), and when the voltage was 2.2 V, the oxygen generation rate was 332.05 mol/(cm2·s); due to the change in the oxygen production rate, the pressure difference at 2.2 V was 2.5 times than that at 1.6 V. When the stoichiometric number was less than two, the average temperature of the catalyst layer (CL) decreased rapidly with the increase in the water flow rate. When the voltage decreased to 2.1 V, the current density came to the highest value when the stoichiometric number was 0.7, then the current density decreased with an increase in the stoichiometric number. When stoichiometric numbers were higher than five, the surface temperature and current density remained basically stable with the increase in the water flow rate, and the water and thermal management and electrolysis characteristics performed better. The research results could optimize the water supply of electrolysis cells. According to the velocity distribution law of the flow field, the water and thermal management performance of the PEMEC could be estimated, further promoting safety and reliability.","PeriodicalId":504870,"journal":{"name":"Energies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141657513","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Paweł A. Mazurek, Aleksander Chudy, Piotr Hołyszko
As electromobility and especially the electrification of public transportation develops, it is necessary to safeguard human health and minimize environmental impact. Electromagnetic fields generated by the current flowing through on-board batteries, installations, converters, propulsion, air conditioning, heating, lighting, or wireless communication systems in these vehicles may pose risks to drivers and passengers. This research investigates electromagnetic fields induced by extreme low-frequency currents and permanent magnets on electric and trolleybuses implanted in Lublin, Poland. The identification of electromagnetic fields concerned an electric bus model and two trolleybus models. A comparative analysis of the results obtained with the permissible limits in the environment was carried out.
{"title":"Assessment of Electromagnetic Fields in Trolleybuses and Electric Buses: A Study of Municipal Transport Company Lublin’s Fleet","authors":"Paweł A. Mazurek, Aleksander Chudy, Piotr Hołyszko","doi":"10.3390/en17143412","DOIUrl":"https://doi.org/10.3390/en17143412","url":null,"abstract":"As electromobility and especially the electrification of public transportation develops, it is necessary to safeguard human health and minimize environmental impact. Electromagnetic fields generated by the current flowing through on-board batteries, installations, converters, propulsion, air conditioning, heating, lighting, or wireless communication systems in these vehicles may pose risks to drivers and passengers. This research investigates electromagnetic fields induced by extreme low-frequency currents and permanent magnets on electric and trolleybuses implanted in Lublin, Poland. The identification of electromagnetic fields concerned an electric bus model and two trolleybus models. A comparative analysis of the results obtained with the permissible limits in the environment was carried out.","PeriodicalId":504870,"journal":{"name":"Energies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141657668","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The paper addresses the overlooked interaction between power-to-gas (P2G) devices and carbon capture and storage (CCS) equipment, along with the stepwise carbon trading mechanism in the context of current multi-park integrated energy microgrids (IEMGs). Additionally, it covers the economic and coordinated low-carbon operation issues in multi-park IEMGs under the carbon trading system. It proposes a multi-park IEMG low-carbon operation strategy based on the synchronous Alternating Direction Method of Multipliers (ADMM) algorithm. The algorithm first enables the distribution of cost relationships among multi-park IEMGs. Then, using a method that combines a CCS device with a P2G unit in line with the tiered carbon trading scheme, it expands on the model of single IEMGs managing thermal, electrical, and refrigeration energy. Finally, the comparison of simulation cases proves that the proposed strategy significantly reduces the external energy dependence while keeping the total cost of the users unchanged, and the cost of interaction with the external grid is reduced by 56.64%, the gas cost is reduced by 27.78%, and the carbon emission cost is reduced by 29.54% by joining the stepped carbon trading mechanism.
{"title":"Considering the Tiered Low-Carbon Optimal Dispatching of Multi-Integrated Energy Microgrid with P2G-CCS","authors":"Zixuan Liu, Yao Gao, Tingyu Li, Ruijin Zhu, Dewen Kong, Hao Guo","doi":"10.3390/en17143414","DOIUrl":"https://doi.org/10.3390/en17143414","url":null,"abstract":"The paper addresses the overlooked interaction between power-to-gas (P2G) devices and carbon capture and storage (CCS) equipment, along with the stepwise carbon trading mechanism in the context of current multi-park integrated energy microgrids (IEMGs). Additionally, it covers the economic and coordinated low-carbon operation issues in multi-park IEMGs under the carbon trading system. It proposes a multi-park IEMG low-carbon operation strategy based on the synchronous Alternating Direction Method of Multipliers (ADMM) algorithm. The algorithm first enables the distribution of cost relationships among multi-park IEMGs. Then, using a method that combines a CCS device with a P2G unit in line with the tiered carbon trading scheme, it expands on the model of single IEMGs managing thermal, electrical, and refrigeration energy. Finally, the comparison of simulation cases proves that the proposed strategy significantly reduces the external energy dependence while keeping the total cost of the users unchanged, and the cost of interaction with the external grid is reduced by 56.64%, the gas cost is reduced by 27.78%, and the carbon emission cost is reduced by 29.54% by joining the stepped carbon trading mechanism.","PeriodicalId":504870,"journal":{"name":"Energies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141658606","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The development of fractures under multiple geological tectonic movements affects the occurrence and efficient production of free gas in deep coal reservoirs. Taking the No.8 deep coal seam of the Benxi formation in the Linxing area as the object, a method for evaluating favorable fracture areas is established based on the combination of field joint staging, paleogeological model reconstruction under structural leveling, finite element numerical simulation, and fracture development criteria. The results show that a large number of shear fractures and fewer tensile joints are developed in the Benxi formation in the field and mainly formed in the Yanshanian and Himalayan periods. The dominant strikes of conjugate joints in the Yanshanian period are NWW (100°~140°) and NNW (150°~175°), with the maximum principal stress magnitude being 160 MPa along the NW orientation. Those in the Himalayan period are in the NNE direction (0°~40°) and the EW direction (80°~110°), with the maximum principal stress magnitude being 100 MPa along the NE orientation. The magnitudes of the maximum principal stress of the No. 8 deep coal seam in the Yanshanian period are between −55 and −82 MPa, indicative of compression; those in the Himalayan period are from −34 to −70 MPa in the compressive stress form. Areas with high shear stress values are mainly distributed in the central magmatic rock uplift, indicating the influence of magmatic rock uplift on in situ stress distribution and fracture development. Based on the comprehensive evaluation factors of fractures, the reservoir is divided into five classes and 24 favorable fracture areas. Fractures in Class I areas and Class II areas are relatively well developed and were formed under two periods of tectonic movements. The method for evaluating favorable fracture areas is not only significant for the prediction of fractures and free gas contents in this deep coal reservoir but also has certain reference value for other reservoirs.
多种地质构造运动下断裂的发育影响着深部煤储层游离气的发生和有效生产。以临兴地区本溪地层 8 号深煤层为对象,结合野外节理分期、构造平差下古地理学模型重建、有限元数值模拟和断裂发育标准,建立了有利断裂带评价方法。结果表明,野外本溪地层中剪切断裂发育较多,张拉节理较少,主要形成于燕山期和喜马拉雅期。燕山期共轭节理的主要走向为 NWW(100°~140°)和 NNW(150°~175°),沿 NW 走向的最大主应力为 160 兆帕。喜马拉雅山时期的最大主应力位于 NNE 向(0°~40°)和 EW 向(80°~110°),沿 NE 向的最大主应力为 100 兆帕。8号深煤层在燕山期的最大主应力值在-55~-82 MPa之间,为压缩应力形式;在喜马拉雅期的最大主应力值在-34~-70 MPa之间,为压应力形式。剪应力值较高的区域主要分布在岩浆岩隆起的中部,表明岩浆岩隆起对原位应力分布和断裂发育的影响。根据断裂的综合评价因素,将储层划分为 5 个等级和 24 个有利断裂区。Ⅰ类区和Ⅱ类区断裂相对发育,是在两个时期的构造运动中形成的。有利断裂带评价方法不仅对该深层煤储层的断裂和游离气含量预测具有重要意义,而且对其他储层也具有一定的参考价值。
{"title":"Evaluation of Favorable Fracture Area of Deep Coal Reservoirs Using a Combination of Field Joint Observation and Paleostress Numerical Simulation: A Case Study in the Linxing Area","authors":"shihu Zhao, Yanbin Wang, Yali Liu, Zengqing Liu, Xiang Wu, Xinjun Chen, Jiaqi Zhang","doi":"10.3390/en17143424","DOIUrl":"https://doi.org/10.3390/en17143424","url":null,"abstract":"The development of fractures under multiple geological tectonic movements affects the occurrence and efficient production of free gas in deep coal reservoirs. Taking the No.8 deep coal seam of the Benxi formation in the Linxing area as the object, a method for evaluating favorable fracture areas is established based on the combination of field joint staging, paleogeological model reconstruction under structural leveling, finite element numerical simulation, and fracture development criteria. The results show that a large number of shear fractures and fewer tensile joints are developed in the Benxi formation in the field and mainly formed in the Yanshanian and Himalayan periods. The dominant strikes of conjugate joints in the Yanshanian period are NWW (100°~140°) and NNW (150°~175°), with the maximum principal stress magnitude being 160 MPa along the NW orientation. Those in the Himalayan period are in the NNE direction (0°~40°) and the EW direction (80°~110°), with the maximum principal stress magnitude being 100 MPa along the NE orientation. The magnitudes of the maximum principal stress of the No. 8 deep coal seam in the Yanshanian period are between −55 and −82 MPa, indicative of compression; those in the Himalayan period are from −34 to −70 MPa in the compressive stress form. Areas with high shear stress values are mainly distributed in the central magmatic rock uplift, indicating the influence of magmatic rock uplift on in situ stress distribution and fracture development. Based on the comprehensive evaluation factors of fractures, the reservoir is divided into five classes and 24 favorable fracture areas. Fractures in Class I areas and Class II areas are relatively well developed and were formed under two periods of tectonic movements. The method for evaluating favorable fracture areas is not only significant for the prediction of fractures and free gas contents in this deep coal reservoir but also has certain reference value for other reservoirs.","PeriodicalId":504870,"journal":{"name":"Energies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141657961","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jianli Zhao, Yixin Chen, Wenping Dou, Bin Cao, Liming Wang, F. Yin
With the development of UHV transmission technology, large-tonnage disc-type suspension porcelain insulators have been widely used. Insulators with cylindrical heads have the advantages of light weight and high strength compared with traditional insulators with conical heads. Cement is an important part of disc-type suspension porcelain insulators. The drying shrinkage of cement can lead to sliding between cement and porcelain. It can also transform the stress distribution of the porcelain, thus influencing the overall long-term mechanical performance of the insulators. In this paper, the effect of the shrinkage of cement on the stress distribution of porcelain insulators was studied by simulation. In addition, the effect of the drying shrinkage rates of cement on insulators with cylindrical and conical heads were compared. The simulation results show that cylindrical-head insulators can better resist the stress change caused by cement shrinkage than the conical-head insulators, which was beneficial to the long-term performance of the insulators. Based on the tensile stress of porcelain parts, the recommended range of the drying shrinkage rate of cement for insulators with cylindrical heads was presented. The research results are of practical value for the selection of cement.
{"title":"Simulation Study on the Effect of Cement Shrinkage on the Stress Distribution of Large Tonnage Disc-Type Suspension Porcelain Insulators","authors":"Jianli Zhao, Yixin Chen, Wenping Dou, Bin Cao, Liming Wang, F. Yin","doi":"10.3390/en17143407","DOIUrl":"https://doi.org/10.3390/en17143407","url":null,"abstract":"With the development of UHV transmission technology, large-tonnage disc-type suspension porcelain insulators have been widely used. Insulators with cylindrical heads have the advantages of light weight and high strength compared with traditional insulators with conical heads. Cement is an important part of disc-type suspension porcelain insulators. The drying shrinkage of cement can lead to sliding between cement and porcelain. It can also transform the stress distribution of the porcelain, thus influencing the overall long-term mechanical performance of the insulators. In this paper, the effect of the shrinkage of cement on the stress distribution of porcelain insulators was studied by simulation. In addition, the effect of the drying shrinkage rates of cement on insulators with cylindrical and conical heads were compared. The simulation results show that cylindrical-head insulators can better resist the stress change caused by cement shrinkage than the conical-head insulators, which was beneficial to the long-term performance of the insulators. Based on the tensile stress of porcelain parts, the recommended range of the drying shrinkage rate of cement for insulators with cylindrical heads was presented. The research results are of practical value for the selection of cement.","PeriodicalId":504870,"journal":{"name":"Energies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141657073","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}