Open Access. Powered by Scholars. Published by Universities.®

Digital Commons Network™

Open Access. Powered by Scholars. Published by Universities.®

Discipline
Institution
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 51571 - 51600 of 715048

Full-Text Articles in Entire DC Network

Study On Frequency Regulation Characteristics Of Power Grids After Large‑Scale New Energy Integration Under Different Operation Modes, Xin He, Cui Liu, Yun Li Jul 2024

Study On Frequency Regulation Characteristics Of Power Grids After Large‑Scale New Energy Integration Under Different Operation Modes, Xin He, Cui Liu, Yun Li

Journal of Electric Power Science and Technology

The basic mathematical model of doubly-fed induction generator (DFIG) participating in grid frequency regulation is presented. The relationship between wind power penetration, the proportion of wind turbines with adjustable frequency ability, the frequency regulation coefficient of wind turbines, and wind power utilization is derived under different operating modes (such as inertia control or maximum power tracking) after large-scale wind power is connected to the grid. The control strategies for wind turbines to participate in grid frequency regulation under different operating modes are proposed. Taking a grid in southern China as an example, the impact characteristics of wind power injection ratio …

Go to article

Prediction Method Of Corrosion Rate Of Large‑Scale Grounding Grid Based On Ga‑Optimized Bp Neural Network, Weilong Peng, Songwu Zeng, Baoqing Zhang, Zilang Wang, Xiaowen Le, Feng Liang, Yang Xie, Xin Yang Jul 2024

Prediction Method Of Corrosion Rate Of Large‑Scale Grounding Grid Based On Ga‑Optimized Bp Neural Network, Weilong Peng, Songwu Zeng, Baoqing Zhang, Zilang Wang, Xiaowen Le, Feng Liang, Yang Xie, Xin Yang

Journal of Electric Power Science and Technology

The corrosion rate of grounding grid is an important aspect of corrosion state evaluation. The artificial intelligence algorithm model can predict the corrosion rate of the grounding grid well. In view of the problem that the selection of the characteristic input in the current prediction model is not comprehensive enough, based on the theoretical analysis of the grounding grid, the corrosion sampling point of the grounding grid is determined. The physical and chemical properties of the soil and the average growth rate of the grounding grid resistance are proposed as the characteristic input of the prediction model. The genetic algorithm …

Go to article

Molecular Modeling Of Tar-Rich Coals From Northern Shaanxi And Their Molecular Dynamic Characteristics In The Process Of Pyrolysis For Tar Extraction, Guo Wei, Yang Panxi, Yu Zunyi, Yang Fu, Wang Jing, Ma Li, Li Hongqiang, Yang Bolun, Wu Zhiqiang Jul 2024

Molecular Modeling Of Tar-Rich Coals From Northern Shaanxi And Their Molecular Dynamic Characteristics In The Process Of Pyrolysis For Tar Extraction, Guo Wei, Yang Panxi, Yu Zunyi, Yang Fu, Wang Jing, Ma Li, Li Hongqiang, Yang Bolun, Wu Zhiqiang

Coal Geology & Exploration

Objective The pyrolysis process and mechanism of tar-rich coals remain unclear due to their complex structures. Therefore, it is necessary to investigate the structure-activity relationship between their structure and the distributions of their pyrolytic products and determine the mechanism behind their pyrolysis for tar extraction. Methods Focusing on typical tar-rich coals from northern Shaanxi Province, this study calculated and constructed the molecular model of the coals using characterization methods such as carbon-13 nuclear magnetic resonance (13C NMR), Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS), determining the molecular formula at C444H380O74 …

Go to article

Advances In Research On Hydrogenation Saturation Of Polycyclic Aromatic Hydrocarbons In Coal Tar, He Xinfu, Gao Fan, Wu Hongju, Zhang Xiaoqin, Ma Tao, Shi Zhiwei, Zhou Anning, Zhang Yating Jul 2024

Advances In Research On Hydrogenation Saturation Of Polycyclic Aromatic Hydrocarbons In Coal Tar, He Xinfu, Gao Fan, Wu Hongju, Zhang Xiaoqin, Ma Tao, Shi Zhiwei, Zhou Anning, Zhang Yating

Coal Geology & Exploration

Significance Polycyclic aromatic hydrocarbons (PAHs), a predominant component in coal tar, can be used to produce jet fuels with high energy density and thermal stability through hydrogenation saturation. Based on the characteristics of the PAH hydrogenation process, this study proposed that primary challenges in PAH hydrogenation saturation include the resonance energy of PAHs themselves, the spatial site resistance of hydrogenation intermediates, and the competitive adsorption of feedstocks and intermediates on active sites in the catalysts. Progress Based on the review of research progress in catalysts for PAH hydrogenation saturation in recent years, this study analyzed the substantial factor influencing the …

Go to article

Distributed Energy Trading Models Utilizing Reinforcement Learning And Game-Theoretic Based Approaches In Smart Grids, Nicholas Kemp Jul 2024

Distributed Energy Trading Models Utilizing Reinforcement Learning And Game-Theoretic Based Approaches In Smart Grids, Nicholas Kemp

Electrical and Computer Engineering ETDs

Community-driven energy initiatives have become crucial for effective energy management, particularly in trading and management. The rise of Distributed Energy Resources in smart grids demands a redesign of traditional Demand Response Management (DRM) models to account for prosumers' dynamic behavior in energy markets. Decentralization, including peer-to-peer (P2P) energy trading, is vital for resilience and sustainability. This thesis introduces two coalitional DRM models: one based on hedonic community formation games, and the other combining matching theory with coalition games. These models empower prosumers to autonomously select energy trading communities using partially available data. To optimize energy consumption, two additional models are …

Go to article

Strong Gelfand Pairs Of Some Finite Groups, Joseph E. Marrow Jul 2024

Strong Gelfand Pairs Of Some Finite Groups, Joseph E. Marrow

Theses and Dissertations

Strong Gelfand pairs describe a relation between a group and a subgroup, using a relation between inner products of their characters. We find all strong Gelfand pairs of the dihedral and dicyclic groups, and several of the sporadic groups. We provide some results for the strong Gelfand pairs of the affine linear groups, in addition to the exceptional classical groups $\mathrm{Sp}_4(q)$ for $q$ a power of $2$.

Go to article

Analysis Of Power Quality Issues And Quantitative Evaluation Of Additional Losses In Low Voltage Distribution Networks Connected To Household Photovoltaics, Yu Han, Qian Zhou, Yong Li, Xinke Bian, Wei Deng, Haiyun An, Chuanwen Zhang Jul 2024

Analysis Of Power Quality Issues And Quantitative Evaluation Of Additional Losses In Low Voltage Distribution Networks Connected To Household Photovoltaics, Yu Han, Qian Zhou, Yong Li, Xinke Bian, Wei Deng, Haiyun An, Chuanwen Zhang

Journal of Electric Power Science and Technology

Quantitative analysis of additional losses in low-voltage distribution networks is one of the necessary ways to achieve energy conservation and loss reduction in power systems, in response to the serious increase in additional losses caused by the disorderly access of household photovoltaics. This paper focuses on the quantitative relationship between the additional losses of household photovoltaic power generation and distribution lines after being connected to the power grid. Firstly, a theoretical analysis is conducted on the changes in characterization of additional losses for household photovoltaic (PV) access. An equivalent circuit and mathematical model are established for active low-voltage distribution networks …

Go to article

Identification Of Key Links In Integrated Energy System Based On Power Flow And Complex Network Theory, Siqi Wang, Zhixian Liang, Zhijie Wang, Hong Wang Jul 2024

Identification Of Key Links In Integrated Energy System Based On Power Flow And Complex Network Theory, Siqi Wang, Zhixian Liang, Zhijie Wang, Hong Wang

Journal of Electric Power Science and Technology

The identification of key links in a comprehensive energy system is of great significance for the research and improvement of system vulnerability. Aiming at the problem that the traditional reductionism method can not explain the system level and the influence of energy flow is not considered in the analysis of complex network, a key link identification method of the IES based on power flow and complex network structure is proposed. Firstly, a comprehensive energy complex network model is established based on power flow, and the mathematical model parameters and power flow results of the IES are introduced into the modeling …

Go to article

In Re: Steven D\'Agostino Jul 2024

In Re: Steven D\'Agostino

2024 Decisions

USDC for the District of New Jersey

Go to article

Pilot Experiment For Underground In-Situ Pyrolysis Of Tar-Rich Coal In The Northern Shaanxi Province, Duan Zhonghui, Yang Fu, Wang Zhendong, Ma Li, Duan Xiaoqing, Cao Husheng, Chen Liang Jul 2024

Pilot Experiment For Underground In-Situ Pyrolysis Of Tar-Rich Coal In The Northern Shaanxi Province, Duan Zhonghui, Yang Fu, Wang Zhendong, Ma Li, Duan Xiaoqing, Cao Husheng, Chen Liang

Coal Geology & Exploration

Objective The breakthrough of the pilot experiment for underground in-situ pyrolysis of tar-rich coal in the northern Shaanxi has added new vitality to the research on in-situ conversion of fossil energy such as tar-rich coal and oil shale, and the results have attracted wide attention both inside and outside the industry. The research on underground in-situ pyrolysis of tar rich coal is still in its infancy, lacking systematic research on field engineering data.Methods Based on the pilot experiment, the main geological conditions and engineering difficulties have been clarified, and the progress of underground in-situ pyrolysis has been summarized. The …

Go to article

Geological Factors Controlling The Occurrence Of Carboniferous-Permian Tar-Rich Coals In The Ningdong Coalfield, Huang Pengcheng, Guo Weiyong, Ji Xiaoyan, Cai Feifei, Zhang Zhifeng, Huang Kang, Cheng Yunqiang, Liu Zheng, Wang Bei, Chen Rong, Shi Qingmin Jul 2024

Geological Factors Controlling The Occurrence Of Carboniferous-Permian Tar-Rich Coals In The Ningdong Coalfield, Huang Pengcheng, Guo Weiyong, Ji Xiaoyan, Cai Feifei, Zhang Zhifeng, Huang Kang, Cheng Yunqiang, Liu Zheng, Wang Bei, Chen Rong, Shi Qingmin

Coal Geology & Exploration

Objective The Ningdong Coalfield of the Ordos Basin boasts abundant tar-rich coal resources, of which tar-rich coals in the Carboniferous-Permian coal seams exhibit unique occurrence characteristics due to differences in thermal evolution and sedimentary environments. Methods This study analyzed the occurrence characteristics and critical material composition of tar-rich coals in the Hongdunzi and Siguquan mining areas. Based on this, it explored the controlling effects of the degree of coalification and sedimentary environment on the tar yield. Results and Conclusions The results indicate that the Carboniferous-Permian coal seams in the Ningdong Coalfield exhibit average tar yields ranging from 7.15% to 11.07%, …

Go to article

Distributions Of Products From The Pyrolysis Of Tar-Rich Coals For Tar Extraction In Northern Shaanxi Province, China, Yu Zunyi, Guo Wei, Yang Panxi, Gao Kun, Yang Fu, Ma Li, Wang Jing, Li Hongqiang, Yang Bolun, Wu Zhiqiang Jul 2024

Distributions Of Products From The Pyrolysis Of Tar-Rich Coals For Tar Extraction In Northern Shaanxi Province, China, Yu Zunyi, Guo Wei, Yang Panxi, Gao Kun, Yang Fu, Ma Li, Wang Jing, Li Hongqiang, Yang Bolun, Wu Zhiqiang

Coal Geology & Exploration

Objective Tar-rich coals stand as a special type of coal resource that integrates coal, oil, and gas properties. These coals, boasting abundant hydrogen-rich structures such as side chains and bridge bonds with aliphatic structures, are prone to crack and produce tar and gas during pyrolysis. These establish tar-rich coals as ideal raw materials that produce oil and gas through thermal conversion. Presently, the research into tar extraction from tar-rich coals through pyrolysis remains in its initial stage, and exploring the impacts of technological conditions, including heat carrier, heating type, and pyrolysis temperature, on the pyrolysis process holds critical significance for …

Go to article

Simulation Of The Pyrolysis Process Of Tar-Rich Coals In An H2O Atmosphere Based On The Reactive Force Field Molecular Dynamics, Huang Zibo, Liu Qianru, Liu Hong, Zhou Wenjing, Wei Jinjia Jul 2024

Simulation Of The Pyrolysis Process Of Tar-Rich Coals In An H2O Atmosphere Based On The Reactive Force Field Molecular Dynamics, Huang Zibo, Liu Qianru, Liu Hong, Zhou Wenjing, Wei Jinjia

Coal Geology & Exploration

Objective Tar-rich coal resources, abundant in China, can be converted into energy products (e.g., chemicals and gas/liquid fuels) through pyrolysis, thus alleviating the country’s dependence on oil and gas imports. A thorough understanding of the product evolution and reaction mechanisms of the pyrolysis of tar-rich coals is crucial to research into the clean and efficient conversion processes of coals. Methods Based on the reactive force field molecular dynamics (ReaxFF MD), this study simulated the pyrolysis process of tar-rich coals (long-flame coals) and explored the impacts of the H2O atmosphere on the distribution of pyrolytic products, along with the …

Go to article

Spatiotemporal Distributions Of Typical Contaminants From The In-Situ Pyrolysis Of Tar-Rich Coals, Tian Hua, Zhang Ruolin, Wang Qianji, Wu Xiaoyu, Zhang Lei, Zhang Lingru, Fang Siyuan Jul 2024

Spatiotemporal Distributions Of Typical Contaminants From The In-Situ Pyrolysis Of Tar-Rich Coals, Tian Hua, Zhang Ruolin, Wang Qianji, Wu Xiaoyu, Zhang Lei, Zhang Lingru, Fang Siyuan

Coal Geology & Exploration

Objective and Methods Under high temperatures, oil and gas produced from the in situ pyrolysis of tar-rich coals will migrate toward and accumulate in the overburden strata after passing through the fracture zones on the coal seam roof, causing potential contamination risks for the underground environment. To understand the release and distribution characteristics of typical contaminants generated from the underground pyrolysis of tar-rich coals, this study investigated the typical tar-rich coals from the Shenfu mining area of the Jurassic coalfield in northern Shaanxi Province. Based on data on the stratigraphic structures and lithology and using the self-developed equipment for similarity …

Go to article

Downhole Heaters For In-Situ Pyrolysis Of Tar-Rich Coals：A Review And Prospects, Wang Zhendong, Duan Zhonghui, Yang Fu, Ma Li Jul 2024

Downhole Heaters For In-Situ Pyrolysis Of Tar-Rich Coals：A Review And Prospects, Wang Zhendong, Duan Zhonghui, Yang Fu, Ma Li

Coal Geology & Exploration

Significance China boasts abundant tar-rich coal resources, which prove to be potential coal-based oil and gas resources capable of ensuring China's energy security. Extracting hydrogen while preserving carbon through the in-situ pyrolysis of tar-rich coals has developed into a trend in the clean and low-carbon utilization of coal resources. Downhole heaters serve as critical equipment for the efficient in-situ pyrolysis of tar-rich coals. Advances Based on investigations and the systematic collection of relevant information and data, this study offers a brief introduction of the currently used methods for in-situ convection heating, focusing on the present situation of the research and …

Go to article

Exploring The Pyrolysis Of Tar-Rich Coals Under The Catalysis Of Cerium-Modified Magnetic Core-Shell Hzsm-5, Zhou Anning, Zhang Zhi, Chen Yongan, Zhang Huaiqing, Bai Zhuangwei, Shi Zhiwei, He Xinfu Jul 2024

Exploring The Pyrolysis Of Tar-Rich Coals Under The Catalysis Of Cerium-Modified Magnetic Core-Shell Hzsm-5, Zhou Anning, Zhang Zhi, Chen Yongan, Zhang Huaiqing, Bai Zhuangwei, Shi Zhiwei, He Xinfu

Coal Geology & Exploration

Objective Tar-rich coals are valuable resources integrating coal, tar, and gas properties. Catalytic pyrolysis serves as a significant approach for achieving green and low-carbon development of tar-rich coals. However, the research and development of efficient and recyclable catalysts for the pyrolysis of tar-rich coals remains highly challenging. Methods With HZSM-5@SiO2@MgFe2O4 (HSMF) as the raw material, this study prepared HZSM-5@SiO2@MgFe2O4 (mHSMF) with a hierarchical porous structure using the hydrothermal method and alkali modification, followed by the preparation of cerium-modified mHSMF (5-CeO2/mHSMF) using the precipitation method. Employing a fixed-bed reactor, …

Go to article

Using Alma Apis, Sru Lookups, And Ids Logic To Enhance Alma/Illiad Integration, Timothy Jackson, Bill Jones, Angela Persico Jul 2024

Using Alma Apis, Sru Lookups, And Ids Logic To Enhance Alma/Illiad Integration, Timothy Jackson, Bill Jones, Angela Persico

Conference Presentations

No abstract provided.

Go to article

State Estimation Of Power System Based On Cubature Kalman Filter Under False Data Injection Attacks, Mengyan Chang, Yonghui Liu Jul 2024

State Estimation Of Power System Based On Cubature Kalman Filter Under False Data Injection Attacks, Mengyan Chang, Yonghui Liu

Journal of Electric Power Science and Technology

Aiming at the problem of system state estimation under false data injection attacks, the mathematical model of power system was established according to the third-order model of generator and the model of automatic voltage regulator, taking the cyber-physical power system as the research object. The exponential smoothing method was used to predict the measured value, and by comparing the predicted value with the actual measured value, it detected whether there were false data injection attacks in the system. If the detection results determine that the system being subjected to false data injection attacks, the predicted value is used instead of …

Go to article

The College Campus, A Place Of Learning, And A Place Of Healing, Huma Bashir, Joshua Francis Jul 2024

The College Campus, A Place Of Learning, And A Place Of Healing, Huma Bashir, Joshua Francis

Human Services Faculty Publications

The COVID-19 pandemic and its aftermath have precipitated a marked increase in mental health needs among college students. Lockdowns, the sudden shift to remote learning, and social distancing mandates have compounded existing challenges, highlighting a trend that has evolved over the past two decades. Despite heightened demand for mental health support, colleges struggle to meet these needs amid the emotional aftermath of COVID-19 effectively. Recognizing the pivotal role of higher education institutions in shaping future leaders and addressing and enhancing the mental well-being of the college community is imperative to foster an environment conducive to learning and healing. This paper …

Go to article

Survey Of Space Professionals’ Perception Of Satellite Cybersecurity From 2012 To 2022: Decision-Makers’ Thoughts On Satellite Cybersecurity Evolving, Rachel C. Jones Jul 2024

Survey Of Space Professionals’ Perception Of Satellite Cybersecurity From 2012 To 2022: Decision-Makers’ Thoughts On Satellite Cybersecurity Evolving, Rachel C. Jones

Aerospace Sciences Student Publications

Cyberattacks on space assets are often portrayed in vague terms of doubt and mystery. Several claims depict satellites being compromised or attacked, but little corroboration has been published or made publicly available. As the commercial space industry grows, increased concern with space cybersecurity will prompt commercial satellite decision-makers to analyze the often-undefined risk of cyberattacks against satellites. This article identifies and characterizes the nature of cybersecurity risks to space assets and postulates why space professionals might not prioritize cybersecurity. Additional information was captured from a decadal survey of space professionals conducted in 2012 and 2022. The results show a rise …

Go to article

Information Geometric Approaches To Optimal Experimental Design And Reduced-Order Modeling In Ocean Acoustics, Jay C. Spendlove Jul 2024

Information Geometric Approaches To Optimal Experimental Design And Reduced-Order Modeling In Ocean Acoustics, Jay C. Spendlove

Theses and Dissertations

This thesis demonstrates the application of information geometry to problems in underwater acoustics. Information geometry combines the fields of information theory and differential geometry by interpreting a multiparameter model as a Riemannian manifold in an ambient data space. Information geometry tools are especially powerful in context of problems of experimental design and model selection in ocean acoustics. The application area specifically considered in this research is geoacoustic inversion, where seabed parameter values are inferred from acoustical data. Chapter 2 contains a paper submitted to the Journal of Theoretical and Computational Acoustics, which introduces information geometry tools such as the model …

Go to article

Documentation Of Norm Negotiation In A Secondary Mathematics Classroom, Michelle R. Bagley Jul 2024

Documentation Of Norm Negotiation In A Secondary Mathematics Classroom, Michelle R. Bagley

Theses and Dissertations

While previous mathematics education research has shown that norms can change in mathematics classrooms, little research has closely documented the struggles, concessions, and compromises involved in the negotiation process. Negotiating norms is a complex process entailing deliberate teacher moves intended to promote norms, often met with misunderstandings or resistance from students. This thesis documented the negotiation process that occurred when a teacher attempted to require conceptual explanations from students who had not previously been accustomed to doing so. I recorded six days of instruction in a 9th grade algebra unit, transcribed the class discussions, and inferred norms "at play" for …

Go to article

Comparison Between Ribosomal Assembly And Machine Learning Tools For Microbial Identification Of Organisms With Different Characteristics, Stephanie Chau, Carlos Rojas, Jorjeta G. Jetcheva, Mary Markart, Sudha Vijayakumar, Sophia Yuan, Vincent Stowbunenko, Amanda N. Shelton, William B. Andreopoulos Jul 2024

Comparison Between Ribosomal Assembly And Machine Learning Tools For Microbial Identification Of Organisms With Different Characteristics, Stephanie Chau, Carlos Rojas, Jorjeta G. Jetcheva, Mary Markart, Sudha Vijayakumar, Sophia Yuan, Vincent Stowbunenko, Amanda N. Shelton, William B. Andreopoulos

Faculty Research, Scholarly, and Creative Activity

Background: Genome assembly tools are used to reconstruct genomic sequences from raw sequencing data, which are then used for identifying the organisms present in a metagenomic sample. Methodology: More recently, machine learning approaches have been applied to a variety of bioinformatics problems, and in this paper, we explore their use for organism identification. We start by evaluating several commonly used metagenomic assembly tools, including PhyloFlash, MEGAHIT, MetaSPAdes, Kraken2, Mothur, UniCycler, and PathRacer, and compare them against state-of-the-art deep learning-based machine learning classification approaches represented by DNABERT and DeLUCS, in the context of two synthetic mock community datasets. Results: Our analysis …

Go to article

Table Of Contents, The Editors Jul 2024

Table Of Contents, The Editors

Coal Geology & Exploration

No abstract provided.

Go to article

Strategic Value And Scientific Exploration Of In-Situ Pyrolysis Of Tar-Rich Coals, Wang Shuangming, Shi Qingmin, Sun Qiang, Cui Shidong, Kou Bingyang, Qiao Junwei, Geng Jishi, Zhang Lei, Tian Hua, Jiang Pengfei, Cai Yue, Liu Lang Jul 2024

Strategic Value And Scientific Exploration Of In-Situ Pyrolysis Of Tar-Rich Coals, Wang Shuangming, Shi Qingmin, Sun Qiang, Cui Shidong, Kou Bingyang, Qiao Junwei, Geng Jishi, Zhang Lei, Tian Hua, Jiang Pengfei, Cai Yue, Liu Lang

Coal Geology & Exploration

Background Given China's significant demand shortfall of oil and gas, numerous constraints on oil and gas supply, an arduous task of green and low-carbon energy transition of coals, tar-rich coals, a type of coal resource integrating the properties of coal, oil, and gas, have great potential for increasing the oil and gas supply of the country. Advances Despite the successful engineering test conducted in Yulin, Shaanxi Province, in-situ pyrolysis of tar-rich coals remains in its exploratory stage. This technology holds great strategic value in two aspects: (1) It enables reduced demand shortfall of oil and gas in China to enhance …

Go to article

Numerical Simulations Of The Evolutionary Patterns Of Multi-Physical Fields During The In-Situ Pyrolysis Of Tar-Rich Coals, Yang Fu, Cheng Xiangqiang, Li Mingjie, Wu Zhiqiang, Wei Jinjia, Cao Husheng Jul 2024

Numerical Simulations Of The Evolutionary Patterns Of Multi-Physical Fields During The In-Situ Pyrolysis Of Tar-Rich Coals, Yang Fu, Cheng Xiangqiang, Li Mingjie, Wu Zhiqiang, Wei Jinjia, Cao Husheng

Coal Geology & Exploration

Objective The in-situ pyrolysis of tar-rich coals, an emerging technology for coal resource utilization characterized by cleanliness, high efficiency, and safety, is still in its initial development stage. This technology is greatly influenced by the evolutionary patterns of multi-physical fields and critical process parameters. Methods A numerical simulation model involving multi-physical fields was established by coupling fluid flow, heat transfer, and chemical reactions, and its reliability was verified by comparing the numerical simulation results with the pyrolysis experimental results of cylindrical coal samples. Based on the pilot test conditions, the impacts of permeability, heat-carrier flow rate, and fracture zone height …

Go to article

Impacts Of The Caking Property Of Tar-Rich Coals On Their Pore Structure Evolution And Seepage During Pyrolysis, Chang Zhibing, Wang Chuchu, Kuang Wenhao, Tang Ying, Wu Xiaodan, Liu Shuqin Jul 2024

Impacts Of The Caking Property Of Tar-Rich Coals On Their Pore Structure Evolution And Seepage During Pyrolysis, Chang Zhibing, Wang Chuchu, Kuang Wenhao, Tang Ying, Wu Xiaodan, Liu Shuqin

Coal Geology & Exploration

Objective The in-situ pyrolysis of tar-rich coals stands as a technique whereby coal seams are heated underground to produce tar and gas products. During the in-situ pyrolysis, the injection of heating media and the production of tar and gas are affected by the pore structure and permeability of coal seams. Since pyrolysis of caking tar-rich coals is accompanied by the formation of colloids, the pore structure and permeability of caking tar-rich coals differ from those of non-caking tar-rich coals. Methods Caking tar-rich coals were pyrolyzed at 300, 400, 500, and 600 ℃. During the pyrolysis, the pore parameters of the …

Go to article

Identification Of Tar-Rich Coal Based On The True Density And Natural Gamma Ray Response Of Coals, Shi Qingmin, Geng Xuhu, Wang Shuangming, Cai Yue, Han Bo, Wang Shengquan, Zhang Zhehao, He Yufei Jul 2024

Identification Of Tar-Rich Coal Based On The True Density And Natural Gamma Ray Response Of Coals, Shi Qingmin, Geng Xuhu, Wang Shuangming, Cai Yue, Han Bo, Wang Shengquan, Zhang Zhehao, He Yufei

Coal Geology & Exploration

Objective Tar yield, derived from the Gray-King assay, serves as the sole metric for evaluating tar-rich coal. However, insufficient exploration data hinder its effective application in the fine-scale evaluation of extensive tar-rich coal. Methods Based on binary classification, this study proposed the optimal thresholds for tar-rich coal identification using true density (ρ) and natural gamma-ray (GR) log. Moreover, this study elucidated the intrinsic mechanisms behind the significant petrophysical parameter responses of tar-rich coal. Results and Conclusions Key findings are as follows: (1) Coals with various metamorphic grades differ in identification threshold. For instance, long-flame tar-rich coal, the optimal …

Go to article

A Log-Based Method For Evaluating The Tar Yield Of Tar-Rich Coal, Tian Han, Li Ning, Wang Shuangming, Wu Hongliang, Feng Zhou, Wang Kewen, Wang Guiwen Jul 2024

A Log-Based Method For Evaluating The Tar Yield Of Tar-Rich Coal, Tian Han, Li Ning, Wang Shuangming, Wu Hongliang, Feng Zhou, Wang Kewen, Wang Guiwen

Coal Geology & Exploration

Objective As a kind of coal-based oil and gas resource, tar-rich coal is significant for the supply of oil and gas resources, as well as the clean and efficient utilization of coals. Presently, the identification of tar-rich coals primarily depends on the Gray-King assay. In contrast, there is a lack of studies on the accurate identification and evaluation of tar-rich coal using geophysical methods. Methods This study investigated coals in the Jurassic Xishanyao and Badaowan Formations in Santanghu Basin, Xinjiang. Based on petrophysical experiments, as well as the typical log response characteristics of tar-rich coal, this study developed a new …

Go to article

A Method For Predicting The Tar Yield Of Tar-Rich Coals Based On The Bp Neural Network Using Multiple Indicators Of Coal Petrography And Coal Quality, Qiao Junwei, Wang Changjian, Zhao Hongchao, Shi Qingmin, Zhang Yu, Fan Qi, Wang Duo, Yuan Dandan Jul 2024

A Method For Predicting The Tar Yield Of Tar-Rich Coals Based On The Bp Neural Network Using Multiple Indicators Of Coal Petrography And Coal Quality, Qiao Junwei, Wang Changjian, Zhao Hongchao, Shi Qingmin, Zhang Yu, Fan Qi, Wang Duo, Yuan Dandan

Coal Geology & Exploration

Objective Tar yield, the most important coal quality parameter for coal utilization through low-temperature pyrolysis, determines the clean utilization of tar-rich coals. However, various constraints result in limited test data on tar yield in the geological exploration stage of coals, substantially restricting the fine-scale assessment and efficient utilization of tar-rich coals. Methods To achieve more scientific and accurate fine-scale tar-rich coal assessments, this study examined 1073 sets of lithotype and coal quality data obtained previously from a Jurassic coalfield in northern Shaanxi. From these data, 141 sets with 20 lithotype and coal quality parameters regarding macerals, proximate analysis, ultimate analysis, …

Go to article

First Prev Next Last