Widely concerns over the carbon emission problems have been aroused. Prior studies have documented the correlation between the carbon emission market and industries separately. This study compared the tail risks and risk spillover effect of the carbon emission and 11 industries markets in China and the European Union (EU) by using the multivariate multi‐quartile conditional autoregressive at‐risk model. Moreover, to evaluate the risk spillover of each market under extreme risk conditions in time domain and frequency domain, DY spillover index and BK spillover index were constructed via generalized forecast error variance decomposition and generalized causation spectrum, respectively. Findings are as follows: (1) The tail risks and fluctuation of the trend of Chinese industry markets reflects more higher and larger than those in the EU; (2) The EU suffers from smaller external shocks, while China has the opposite result and can recover relatively faster; (3) In China, energy, industrial, information technology, financial, real estate, consumer goods, carbon emissions, and discretionary consumption industries are risk spillover industries, while healthcare, materials, telecommunication services, and utilities industries are risk receiving industries. In contrast, the risk spillover industries in the EU remain consistent with those of the Chinese markets except for the materials, discretionary consumption, consumer goods, information technology and real estate industries. (4) On the short‐term, medium‐term and long‐term scales, the risk spillover of China's carbon emission trading market and various industries is basically consistent with that of the EU. These findings contribute to reducing greenhouse gas emissions and achieving the goal of carbon peak and carbon neutrality.
{"title":"Research on the risk spillover effect of carbon emission trading market and various industry markets in China and the European Union","authors":"Hua Cui, Yixin Fan, Juchao Li","doi":"10.1002/ese3.1907","DOIUrl":"https://doi.org/10.1002/ese3.1907","url":null,"abstract":"Widely concerns over the carbon emission problems have been aroused. Prior studies have documented the correlation between the carbon emission market and industries separately. This study compared the tail risks and risk spillover effect of the carbon emission and 11 industries markets in China and the European Union (EU) by using the multivariate multi‐quartile conditional autoregressive at‐risk model. Moreover, to evaluate the risk spillover of each market under extreme risk conditions in time domain and frequency domain, DY spillover index and BK spillover index were constructed via generalized forecast error variance decomposition and generalized causation spectrum, respectively. Findings are as follows: (1) The tail risks and fluctuation of the trend of Chinese industry markets reflects more higher and larger than those in the EU; (2) The EU suffers from smaller external shocks, while China has the opposite result and can recover relatively faster; (3) In China, energy, industrial, information technology, financial, real estate, consumer goods, carbon emissions, and discretionary consumption industries are risk spillover industries, while healthcare, materials, telecommunication services, and utilities industries are risk receiving industries. In contrast, the risk spillover industries in the EU remain consistent with those of the Chinese markets except for the materials, discretionary consumption, consumer goods, information technology and real estate industries. (4) On the short‐term, medium‐term and long‐term scales, the risk spillover of China's carbon emission trading market and various industries is basically consistent with that of the EU. These findings contribute to reducing greenhouse gas emissions and achieving the goal of carbon peak and carbon neutrality.","PeriodicalId":11673,"journal":{"name":"Energy Science & Engineering","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142179749","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The expansion of renewable energy (RE) relies on both natural factors and socioeconomic conditions fostered at the regional level. This paper examines the key factors influencing RE development in selected Russian regions. We conducted a literature review, surveyed 250 industry experts, and analyzed reports from energy and rating agencies, along with natural resource maps, to identify specific risks and indicators. Our expert survey revealed that the most significant technical risks are low resource potential (68%), energy system surplus (68%), and the absence of transport logistics with neighboring regions (58%). Politically, the lack of additional sector initiatives (6%) was noted. Economically, the high cost of RE (56%) and insufficient experience with “green” investments (54%) were highlighted. Social factors included low unemployment rates (74%), and the absence of remote areas without power supply (72%). Environmentally, the lack of enterprises for energy unit utilization (84%), low greenhouse gas emissions (60%), and insufficient accessible territories for facilities (58%) were significant concerns. We developed risk profiles for nine Russian regions, categorizing them into leaders, intermediates, and nascent stages of RE market formation. Our findings indicate that the most impactful factors include resource potential, space limitations for energy facilities, proximity to equipment manufacturers, regional support measures, and the development of “green” investment instruments. Conversely, regional investment attractiveness had a lesser influence. On the basis of these insights, we recommend enhancing RE development through refined federal and regional support programs. We propose additional criteria for project selection: (1) minimum construction costs covered by “green” investments and (2) quantitative restrictions on new capacities, considering regional energy system status. Practical recommendations also include developing regional centers for servicing generating facilities and increasing the sector's investment attractiveness to stimulate private investment.
{"title":"Regional perspective on prospects and risks of the renewable energy in Russia","authors":"Galina Chebotareva, Wadim Strielkowski, Alexey Berdnikov, Danil Tinarsky","doi":"10.1002/ese3.1868","DOIUrl":"https://doi.org/10.1002/ese3.1868","url":null,"abstract":"The expansion of renewable energy (RE) relies on both natural factors and socioeconomic conditions fostered at the regional level. This paper examines the key factors influencing RE development in selected Russian regions. We conducted a literature review, surveyed 250 industry experts, and analyzed reports from energy and rating agencies, along with natural resource maps, to identify specific risks and indicators. Our expert survey revealed that the most significant technical risks are low resource potential (68%), energy system surplus (68%), and the absence of transport logistics with neighboring regions (58%). Politically, the lack of additional sector initiatives (6%) was noted. Economically, the high cost of RE (56%) and insufficient experience with “green” investments (54%) were highlighted. Social factors included low unemployment rates (74%), and the absence of remote areas without power supply (72%). Environmentally, the lack of enterprises for energy unit utilization (84%), low greenhouse gas emissions (60%), and insufficient accessible territories for facilities (58%) were significant concerns. We developed risk profiles for nine Russian regions, categorizing them into leaders, intermediates, and nascent stages of RE market formation. Our findings indicate that the most impactful factors include resource potential, space limitations for energy facilities, proximity to equipment manufacturers, regional support measures, and the development of “green” investment instruments. Conversely, regional investment attractiveness had a lesser influence. On the basis of these insights, we recommend enhancing RE development through refined federal and regional support programs. We propose additional criteria for project selection: (1) minimum construction costs covered by “green” investments and (2) quantitative restrictions on new capacities, considering regional energy system status. Practical recommendations also include developing regional centers for servicing generating facilities and increasing the sector's investment attractiveness to stimulate private investment.","PeriodicalId":11673,"journal":{"name":"Energy Science & Engineering","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142223746","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The flexible system of wind turbines refers to the components such as blades, towers, and rotor shafts that are subjected to external forces such as wind loads, inertial forces, and gravity during operation, resulting in deformation and vibration. This paper proposes that dynamic response analysis of the flexible system, through the response data, put forward improvement measures to improve the stability. The flexible dynamic response of wind turbine was analyzed. The fluid dynamics and structural dynamics of wind turbine are analyzed by the finite element method, and the flow chart is combined to get the wind turbine velocity, pressure, shear stress, and vorticity distribution nephogram. The results provide a reference value for monitoring structural state dynamics parameters of large wind turbines. Wind power generation technology is relatively mature, and its proportion in the field of power generation is gradually increasing. Wind energy is inexhaustible and can occupy a place in the development and utilization of new energy for a long time. This study provides an important reference for determining the dynamic parameters of wind turbine operation and improves the stability and reliability of wind turbine operation. The results provide a reference value for monitoring structural state dynamics parameters of large wind turbines.
{"title":"Investigations on rigid–flexible coupling multibody dynamics of 5 MW wind turbine","authors":"Zhanpu Xue, Zhiqiang Zhou, Haijun Lai, Siyuan Shao, Jilai Rao, Yun Li, Long He, Zhiyuan Jia","doi":"10.1002/ese3.1901","DOIUrl":"https://doi.org/10.1002/ese3.1901","url":null,"abstract":"The flexible system of wind turbines refers to the components such as blades, towers, and rotor shafts that are subjected to external forces such as wind loads, inertial forces, and gravity during operation, resulting in deformation and vibration. This paper proposes that dynamic response analysis of the flexible system, through the response data, put forward improvement measures to improve the stability. The flexible dynamic response of wind turbine was analyzed. The fluid dynamics and structural dynamics of wind turbine are analyzed by the finite element method, and the flow chart is combined to get the wind turbine velocity, pressure, shear stress, and vorticity distribution nephogram. The results provide a reference value for monitoring structural state dynamics parameters of large wind turbines. Wind power generation technology is relatively mature, and its proportion in the field of power generation is gradually increasing. Wind energy is inexhaustible and can occupy a place in the development and utilization of new energy for a long time. This study provides an important reference for determining the dynamic parameters of wind turbine operation and improves the stability and reliability of wind turbine operation. The results provide a reference value for monitoring structural state dynamics parameters of large wind turbines.","PeriodicalId":11673,"journal":{"name":"Energy Science & Engineering","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142179751","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Taiping Chen, Xianzhu Wei, Rushan Bie, Yang Li, Bin Xu, Wenbo Wang, Yongxin Liu
A hybrid power station comprising storage pump units and conventional hydropower components holds the potential to enhance the operational flexibility of basin hydroelectric regulation. The storage pumps must possess significant power capacity and operate with high efficiency to ensure viable energy storage. This study investigates the energy dissipation within a two‐stage storage pump using entropy generation theory. The numerical solution of flow energy dissipation (FED) components was obtained for various flow rates using the steady‐state single‐phase shear stress transport k–ω turbulence model. Results indicate that the return channel contributes the most to FED generation within the entire passage, with the FED proportion decreasing from 66.7% to 41.3% as the flow rate increases from 0.5QBEP to 1.2QBEP. The FED generation percentage from the runners increases from 10.4% to 46.9% with increasing flow rate, ranking second. The FED generation percentage attributed from the spiral case ranges from 10.3% to 16.7%, ranking third. Losses from the draft tube are found to be negligible. Flow pattern analysis reveals that FED generation primarily occurs at the junction of inferior flow (flow separation and vortex flow) and the main flow, where significant velocity gradients exist.
{"title":"Analysis of flow energy dissipation of a two‐stage storage pump based on entropy generation theory","authors":"Taiping Chen, Xianzhu Wei, Rushan Bie, Yang Li, Bin Xu, Wenbo Wang, Yongxin Liu","doi":"10.1002/ese3.1900","DOIUrl":"https://doi.org/10.1002/ese3.1900","url":null,"abstract":"A hybrid power station comprising storage pump units and conventional hydropower components holds the potential to enhance the operational flexibility of basin hydroelectric regulation. The storage pumps must possess significant power capacity and operate with high efficiency to ensure viable energy storage. This study investigates the energy dissipation within a two‐stage storage pump using entropy generation theory. The numerical solution of flow energy dissipation (FED) components was obtained for various flow rates using the steady‐state single‐phase shear stress transport <jats:italic>k</jats:italic>–<jats:italic>ω</jats:italic> turbulence model. Results indicate that the return channel contributes the most to FED generation within the entire passage, with the FED proportion decreasing from 66.7% to 41.3% as the flow rate increases from 0.5<jats:italic>Q</jats:italic><jats:sub>BEP</jats:sub> to 1.2<jats:italic>Q</jats:italic><jats:sub>BEP</jats:sub>. The FED generation percentage from the runners increases from 10.4% to 46.9% with increasing flow rate, ranking second. The FED generation percentage attributed from the spiral case ranges from 10.3% to 16.7%, ranking third. Losses from the draft tube are found to be negligible. Flow pattern analysis reveals that FED generation primarily occurs at the junction of inferior flow (flow separation and vortex flow) and the main flow, where significant velocity gradients exist.","PeriodicalId":11673,"journal":{"name":"Energy Science & Engineering","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142179769","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study aimed to increase the scale of oil-based drilling cuttings (OBDCs) resource utilization in the ceramic industry. The sintering process and mechanism were explored based on the analysis of physicochemical properties, phase transitions, and microstructure. The results showed that (1) The main ceramic-technological characteristics of the OBDC were determined, which belonged to high-silica solid waste with a high Si–Al ratio and a low acid–base ratio of oxides. (2) The low meltability temperature of the OBDC could largely influence the determination of the sintering temperature range for ceramic products. (3) The chemical components OBDC provided were involved in the formation of molten phases, which could affect dimensional accuracy and mechanical properties. Meanwhile, the dolomite promoted the formation of closed pores and enhanced lightweight performance. (4) Before 800°C, dolomite decomposed and reacted with SiO2 to form silicate, and then a new feldspar crystal appeared. After 1000°C, orthoclase completely melted into the molten phase, only two phases of quartz and diopside existed in the material until 1150°C. When the temperature was higher than 1350°C, the glass transition of the phase was basically intensified. (5) In the analyzed scenarios, the results indicated OBDC can only be doped in low contents and degrades the ceramic material properties.
{"title":"Valorization of oil-based drilling cuttings as a substitute for bauxite in fracturing proppants application","authors":"Xiaogang Li, Junya Xiong, Zhaozhong Yang, Hao Chen","doi":"10.1002/ese3.1855","DOIUrl":"10.1002/ese3.1855","url":null,"abstract":"<p>This study aimed to increase the scale of oil-based drilling cuttings (OBDCs) resource utilization in the ceramic industry. The sintering process and mechanism were explored based on the analysis of physicochemical properties, phase transitions, and microstructure. The results showed that (1) The main ceramic-technological characteristics of the OBDC were determined, which belonged to high-silica solid waste with a high Si–Al ratio and a low acid–base ratio of oxides. (2) The low meltability temperature of the OBDC could largely influence the determination of the sintering temperature range for ceramic products. (3) The chemical components OBDC provided were involved in the formation of molten phases, which could affect dimensional accuracy and mechanical properties. Meanwhile, the dolomite promoted the formation of closed pores and enhanced lightweight performance. (4) Before 800°C, dolomite decomposed and reacted with SiO<sub>2</sub> to form silicate, and then a new feldspar crystal appeared. After 1000°C, orthoclase completely melted into the molten phase, only two phases of quartz and diopside existed in the material until 1150°C. When the temperature was higher than 1350°C, the glass transition of the phase was basically intensified. (5) In the analyzed scenarios, the results indicated OBDC can only be doped in low contents and degrades the ceramic material properties.</p>","PeriodicalId":11673,"journal":{"name":"Energy Science & Engineering","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ese3.1855","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142179750","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Muhammad Umair Safder, Md Alamgir Hossain, Mohammad J. Sanjari, Junwei Lu
This paper presents a rule‐based energy management system (EMS) designed for a standalone DC microgrid incorporating solar photovoltaic (PV), fuel cell, battery energy storage system (BESS), and electric vehicle. The unpredictable nature of renewable energy sources and the instability of loads pose challenges for maintaining DC bus voltages and power‐sharing arrangements, impacting the microgrid's smooth operation. The proposed EMS aims to ensure power balance between generation and demand, mitigating vulnerabilities of the DC bus to voltage instability caused by fluctuations from both the load and source sides. This is achieved through an autonomous DC bus voltage stabilization strategy, involving the maintenance of a nominal state of energy (SoE) for the BESS and hydrogen fuel consumption for the fuel cell within predefined lower and upper limits. By regulating these two factors, the EMS algorithm facilitates optimal performance of the PV, battery, and fuel cell components. Consequently, the EMS provides decision‐making instructions to each individual energy source, ensuring efficient operation under various conditions. The effectiveness of the proposed EMS is evaluated through hardware‐based testing on a DC microgrid and simulations in the MATLAB Simulink environment across multiple operating scenarios.
{"title":"Rule‐based energy management system for autonomous voltage stabilization in standalone DC microgrid","authors":"Muhammad Umair Safder, Md Alamgir Hossain, Mohammad J. Sanjari, Junwei Lu","doi":"10.1002/ese3.1873","DOIUrl":"https://doi.org/10.1002/ese3.1873","url":null,"abstract":"This paper presents a rule‐based energy management system (EMS) designed for a standalone DC microgrid incorporating solar photovoltaic (PV), fuel cell, battery energy storage system (BESS), and electric vehicle. The unpredictable nature of renewable energy sources and the instability of loads pose challenges for maintaining DC bus voltages and power‐sharing arrangements, impacting the microgrid's smooth operation. The proposed EMS aims to ensure power balance between generation and demand, mitigating vulnerabilities of the DC bus to voltage instability caused by fluctuations from both the load and source sides. This is achieved through an autonomous DC bus voltage stabilization strategy, involving the maintenance of a nominal state of energy (SoE) for the BESS and hydrogen fuel consumption for the fuel cell within predefined lower and upper limits. By regulating these two factors, the EMS algorithm facilitates optimal performance of the PV, battery, and fuel cell components. Consequently, the EMS provides decision‐making instructions to each individual energy source, ensuring efficient operation under various conditions. The effectiveness of the proposed EMS is evaluated through hardware‐based testing on a DC microgrid and simulations in the MATLAB Simulink environment across multiple operating scenarios.","PeriodicalId":11673,"journal":{"name":"Energy Science & Engineering","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142223768","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mohammed O. Bayazed, Ahmed S. Al‐Fatesh, Anis H. Fakeeha, Ahmed A. Ibrahim, Ahmed E. Abasaeed, Abdulaziz I. Alromaeh, Francesco Frusteri, Jehad K. Abu Dahrieh
Catalytic methane decomposition is a promising technology for reducing the reliance on fossil fuels and mitigating the effects of climate change by producing clean hydrogen and value‐added carbon without the emission of greenhouse gases. The aim of the study was to investigate the use of Al2O3‐modified MgO doped iron‐based catalysts for the catalytic decomposition of methane. The catalysts were synthesized using the impregnation method and characterized using various analysis techniques, including Brunauer, Emmett, and Teller, temperature programmed reduction, temperature programmed oxidation, X‐ray diffraction, thermal gravimetric analysis, Raman, scanning electron microscopy, and transmission electron microscopy. The activity of the synthesized catalysts was tested in a packed‐bed reactor with a gas flow rate of 20 mL/min at a temperature of 800°C. The investigation focuses on the influence of incorporating magnesium into alumina catalysts with MgO concentration ranging from (20%–70%), where higher magnesium levels improve catalytic activity by creating more active sites, positively impacting methane decomposition. Enhanced catalyst reducibility and increased particle dispersion lead to improved catalytic properties despite the reduced surface area. The FA70M and FA63M catalysts exhibited almost the same catalytic characteristics and the highest stability and methane conversion among the catalysts investigated, reaching 87% and 85% at 800°C for 120 min. Moreover, both catalysts showed hydrogen yields of 86% and 85%, respectively. The introduction of MgO further increased the total carbon yield from 103% with FA and 39% for FM to 114% and 120% for the respective catalysts (FA70M and FA63M). During the methane decomposition reaction, carbon nanotubes of varying diameters were produced. Higher iron loading resulted in a positive trend.
{"title":"Role of MgO in Al2O3‐supported Fe catalysts for hydrogen and carbon nanotubes formation during catalytic methane decomposition","authors":"Mohammed O. Bayazed, Ahmed S. Al‐Fatesh, Anis H. Fakeeha, Ahmed A. Ibrahim, Ahmed E. Abasaeed, Abdulaziz I. Alromaeh, Francesco Frusteri, Jehad K. Abu Dahrieh","doi":"10.1002/ese3.1867","DOIUrl":"https://doi.org/10.1002/ese3.1867","url":null,"abstract":"Catalytic methane decomposition is a promising technology for reducing the reliance on fossil fuels and mitigating the effects of climate change by producing clean hydrogen and value‐added carbon without the emission of greenhouse gases. The aim of the study was to investigate the use of Al<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub>‐modified MgO doped iron‐based catalysts for the catalytic decomposition of methane. The catalysts were synthesized using the impregnation method and characterized using various analysis techniques, including Brunauer, Emmett, and Teller, temperature programmed reduction, temperature programmed oxidation, X‐ray diffraction, thermal gravimetric analysis, Raman, scanning electron microscopy, and transmission electron microscopy. The activity of the synthesized catalysts was tested in a packed‐bed reactor with a gas flow rate of 20 mL/min at a temperature of 800°C. The investigation focuses on the influence of incorporating magnesium into alumina catalysts with MgO concentration ranging from (20%–70%), where higher magnesium levels improve catalytic activity by creating more active sites, positively impacting methane decomposition. Enhanced catalyst reducibility and increased particle dispersion lead to improved catalytic properties despite the reduced surface area. The FA70M and FA63M catalysts exhibited almost the same catalytic characteristics and the highest stability and methane conversion among the catalysts investigated, reaching 87% and 85% at 800°C for 120 min. Moreover, both catalysts showed hydrogen yields of 86% and 85%, respectively. The introduction of MgO further increased the total carbon yield from 103% with FA and 39% for FM to 114% and 120% for the respective catalysts (FA70M and FA63M). During the methane decomposition reaction, carbon nanotubes of varying diameters were produced. Higher iron loading resulted in a positive trend.","PeriodicalId":11673,"journal":{"name":"Energy Science & Engineering","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142179766","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jun Nian, Cheng He, Bo Zhao, Xiaobo Lv, Chunsheng Deng
In the study, a combined numerical simulation and on‐site monitoring method was used to analyze the asymmetric development characteristics of overlying rock fractures in a goaf under the condition of a goaf side entry formed by roof cutting and to explore the gas accumulation area in the goaf, achieving precise gas extraction from the goaf. The results demonstrates that a double‐balanced arch structure is formed under the condition of a goaf side entry formed by roof cutting, achieving safe retention of the roadway and showing the significance of the pressure relief effect of roof cutting. The collapse movement of the overlying rock on the roof‐cutting side is relatively advanced. The heights of the collapse zone on the roof‐cutting side and the uncut roof side are 28 and 24 m, respectively, and the development heights of the fracture zone are 37 and 42 m, respectively. The fault line on the roof‐cutting side gradually shifts toward the direction of the goaf, and the surface settlement and fracture development are relatively small. There is a clear asymmetric structure in terms of time effect, fault line, fracture zone height, and surface settlement compared to the uncut roof side. The gas is distributed throughout the entire goaf in the roof‐cutting and tunneling mode, and a high‐concentration gas accumulation area is formed near the open–off cut and working face on the high side of the fracture zone. Based on an actual situation, a method of drilling high and low positions in a fracture zone is proposed for extraction. Combined with on‐site monitoring, the goaf was no longer filled with gas during extraction, and the proportion of low‐concentration gas space considerably increased.
{"title":"Asymmetric development of overburden fracture and gas migration law for a goaf of entry formed by roof cutting","authors":"Jun Nian, Cheng He, Bo Zhao, Xiaobo Lv, Chunsheng Deng","doi":"10.1002/ese3.1862","DOIUrl":"https://doi.org/10.1002/ese3.1862","url":null,"abstract":"In the study, a combined numerical simulation and on‐site monitoring method was used to analyze the asymmetric development characteristics of overlying rock fractures in a goaf under the condition of a goaf side entry formed by roof cutting and to explore the gas accumulation area in the goaf, achieving precise gas extraction from the goaf. The results demonstrates that a double‐balanced arch structure is formed under the condition of a goaf side entry formed by roof cutting, achieving safe retention of the roadway and showing the significance of the pressure relief effect of roof cutting. The collapse movement of the overlying rock on the roof‐cutting side is relatively advanced. The heights of the collapse zone on the roof‐cutting side and the uncut roof side are 28 and 24 m, respectively, and the development heights of the fracture zone are 37 and 42 m, respectively. The fault line on the roof‐cutting side gradually shifts toward the direction of the goaf, and the surface settlement and fracture development are relatively small. There is a clear asymmetric structure in terms of time effect, fault line, fracture zone height, and surface settlement compared to the uncut roof side. The gas is distributed throughout the entire goaf in the roof‐cutting and tunneling mode, and a high‐concentration gas accumulation area is formed near the open–off cut and working face on the high side of the fracture zone. Based on an actual situation, a method of drilling high and low positions in a fracture zone is proposed for extraction. Combined with on‐site monitoring, the goaf was no longer filled with gas during extraction, and the proportion of low‐concentration gas space considerably increased.","PeriodicalId":11673,"journal":{"name":"Energy Science & Engineering","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142179765","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nowadays, the use of hybrid systems has become very common all over the world. In this study, the aim is to minimize the use of grid energy to provide heating and cooling energy with the help of a hybrid heat pump equipped with a flat solar collector, phase change material (PCM), and photovoltaic (PV) panels. To achieve the best results, a numerical dynamic model consisting of different solar PV panels in three models, batteries, inverters, and hybrid heat pump along with collector and PCM has been modeled by solving Engineering Equation Solver (EES) and TRNSYS software. According to the proposed scenarios, multi‐objective optimization has been done to simultaneously improve the study answers in several sections by multi‐objective particle swarm optimization algorithm with MATLAB software. Also, economic and environmental optimization is also presented separately for comparing and reviewing solutions. The results of multi‐objective optimization show that the amount of lifecycle cost (LCC) when using polycrystalline panel is 21.26% lower than monocrystalline panel and 38.71% higher than thin film panel. As a result, according to the specific conditions and attitude, you can choose the desired system. Also, in the economic optimization, it was found that the best system is related to the polycrystalline panel, the volume of PCM used in the system is equal to 1 , the number of panels used is 18, and the minimum amount of LCC is $3929.08.
{"title":"Energy, exergy, exergy‐economic, and environmental evaluation of an optimized hybrid photovoltaic heat pump system with solar collector and PCM","authors":"Armin Ghodrati, Abolfazl Ahmadi, Mojtaba Mirhosseini","doi":"10.1002/ese3.1866","DOIUrl":"https://doi.org/10.1002/ese3.1866","url":null,"abstract":"Nowadays, the use of hybrid systems has become very common all over the world. In this study, the aim is to minimize the use of grid energy to provide heating and cooling energy with the help of a hybrid heat pump equipped with a flat solar collector, phase change material (PCM), and photovoltaic (PV) panels. To achieve the best results, a numerical dynamic model consisting of different solar PV panels in three models, batteries, inverters, and hybrid heat pump along with collector and PCM has been modeled by solving Engineering Equation Solver (EES) and TRNSYS software. According to the proposed scenarios, multi‐objective optimization has been done to simultaneously improve the study answers in several sections by multi‐objective particle swarm optimization algorithm with MATLAB software. Also, economic and environmental optimization is also presented separately for comparing and reviewing solutions. The results of multi‐objective optimization show that the amount of lifecycle cost (LCC) when using polycrystalline panel is 21.26% lower than monocrystalline panel and 38.71% higher than thin film panel. As a result, according to the specific conditions and attitude, you can choose the desired system. Also, in the economic optimization, it was found that the best system is related to the polycrystalline panel, the volume of PCM used in the system is equal to 1 , the number of panels used is 18, and the minimum amount of LCC is $3929.08.","PeriodicalId":11673,"journal":{"name":"Energy Science & Engineering","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142223767","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this study, a new method is proposed to quantitatively determine the extraction of boreholes under the effect of time. The main purpose of this method is to divide the gas drilling holes in the monitoring time into two stages: the early stage of extraction and the middle stage of extraction. The early stage of extraction uses the gas pressure difference to detect the gas tightness of the drilling holes and determine the type of gas leakage of the drilling holes. Moreover, the unqualified drilling holes are repaired immediately to ensure that all the drilling holes in the middle stage of the monitoring are the qualified holes at the early stage of the inspection. In the middle of extraction, the average attenuation rate of the fitting attenuation curve of pure gas extraction in the extraction borehole is calculated by monitoring, the growth rate of the linear fitting of the pure air leakage is calculated, and their ratios are used as the basis for judging the repair value of the gas leak borehole and the gas leak borehole. This quantitative evaluation method is used to monitor the extraction effect of four test holes in a field test conducted at Ping Coal Mine 10. The results indicate that, after adopting in situ downhole repair technology in the early stage of extraction, the average air leakage of Borehole No. 4, which failed due to air leakage in the borehole, decreased from 9.33 to 1.26 L/min (a reduction of 86.5%). Similarly, that of Borehole No. 3, which failed due to penetration of fissures in the surrounding rock, had an air leakage drop from 8.35 to 1.34 L/min (a reduction of 84.0%). These improvements demonstrate the remarkable effectiveness of the method. The quantitative evaluation method established in this study is not only simple to operate but also stable and reliable. Thus, it is feasible to be applied in the field, which provides important technical support for the improvement in gas extraction effect during coal mine safety production.
{"title":"Quantitative evaluation of the sealing effect of penetrating gas drilling and in situ repairing technology for smooth holes","authors":"Zuxiang Hu, Yuepeng Yan, Hongqi Yang, Zhancheng Meng, Pengpeng Wen","doi":"10.1002/ese3.1894","DOIUrl":"https://doi.org/10.1002/ese3.1894","url":null,"abstract":"In this study, a new method is proposed to quantitatively determine the extraction of boreholes under the effect of time. The main purpose of this method is to divide the gas drilling holes in the monitoring time into two stages: the early stage of extraction and the middle stage of extraction. The early stage of extraction uses the gas pressure difference to detect the gas tightness of the drilling holes and determine the type of gas leakage of the drilling holes. Moreover, the unqualified drilling holes are repaired immediately to ensure that all the drilling holes in the middle stage of the monitoring are the qualified holes at the early stage of the inspection. In the middle of extraction, the average attenuation rate of the fitting attenuation curve of pure gas extraction in the extraction borehole is calculated by monitoring, the growth rate of the linear fitting of the pure air leakage is calculated, and their ratios are used as the basis for judging the repair value of the gas leak borehole and the gas leak borehole. This quantitative evaluation method is used to monitor the extraction effect of four test holes in a field test conducted at Ping Coal Mine 10. The results indicate that, after adopting in situ downhole repair technology in the early stage of extraction, the average air leakage of Borehole No. 4, which failed due to air leakage in the borehole, decreased from 9.33 to 1.26 L/min (a reduction of 86.5%). Similarly, that of Borehole No. 3, which failed due to penetration of fissures in the surrounding rock, had an air leakage drop from 8.35 to 1.34 L/min (a reduction of 84.0%). These improvements demonstrate the remarkable effectiveness of the method. The quantitative evaluation method established in this study is not only simple to operate but also stable and reliable. Thus, it is feasible to be applied in the field, which provides important technical support for the improvement in gas extraction effect during coal mine safety production.","PeriodicalId":11673,"journal":{"name":"Energy Science & Engineering","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142179767","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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