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A simple method for solving unidirectional methane gas flow in coal seam based on similarity solution

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International Journal of Mining Science and Technology 2018年第2期28卷 331-334页

作者： zhou Yan Meng Qian Lin Baiquan Qin Jilong zhou guiping Key Laboratory of Gas and Fire Control for Coal Mines (China University of Mining & Technology) Ministry of Education School of Computer Science and Technology Jiangsu Normal University

The equation used to model the unidirectional flow of methane gas in coal seams is usually formulated as a nonlinear partial differential equation, which needs to be solved numerically with a computer ***, for people without access to the computer program, the conventional numerical method may be inconvenient. Thus, the objective here is to seek some method simpler than the conventional one for solving the flow problem. A commonly used model of the unidirectional methane gas flow is considered, where the methane adsorption is described by the Langmuir isotherm and the free gas is treated as real gas. By introducing the similarity solution, a simple method for solving the flow model is proposed, which can be done on a hand calculator. It is shown by two examples that the gas pressure profile obtained by the proposed method agrees well with the direct numerical solution of the flow model.

关键词： Coalbed methane Migration Unidirectional flow Similarity solution Simplified solving Numerical method

Day-ahead Optimal Dispatch Model for Coupled System Considering Ladder-type Ramping Rate and Flexible Spinning Reserve of Thermal Power Units

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Journal of Modern Power Systems and Clean Energy 2022年第6期10卷 1482-1493页

作者： Longjie Yang Niancheng zhou guiping zhou Yuan Chi Ning Chen Lei Wang Qianggang Wang Dongfeng Chang State Key Laboratory of Power Transmission Equipment and System Security and New Technology Chongqing UniversityChongqing 400044China State Grid Liaoning Electric Power Company Limited Shenyang 110006China State Key Laboratory of Operation and Control of Renewable Energy&Storage Systems(China Electric Power Research Institute) Nanjing 210003China Xi’an Thermal Power Research Institute Company Limited Xi’an 710054China IEEE

In northern China,thermal power units(TPUs)are important in improving the penetration level of renewable *** such areas,the potentials of coordinated dispatch of renewable energy sources(RESs)and TPUs can be better realized,if RESs and TPUs connected to the power grid at the same point of common coupling(PCC)are dispatched as a coupled ***,the definition of the coupled system is introduced,followed by an analysis on its ***,based on the operation characteristics of deep peak regulation(DPR)of TPUs in the coupled system,the constraint of the ladder-type ramping rate applicable for day-ahead dispatch is proposed,and the corresponding flexible spinning reserve constraint is further ***,considering these constraints and peak regulation ancillary services,a day-ahead optimal dispatch model of the coupled system is ***,the operational characteristics and advantages of the coupled system are analyzed in several case studies based on a real-world power grid in Liaoning province,*** numerical results show that the coupled system can further improve the economic benefits of RESs and TPUs under the existing policies.

关键词： Coupled system ladder-type ramping rate flexible spinning reserve day-ahead optimal dispatch deep peak regulation peak regulation ancillary services

Dispatch Model for Integrated Heat and Power Systems Considering Internal Composition of CHP Plants

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CSEE Journal of Power and Energy Systems 2021年第2期7卷 396-407页

作者： Tuo Jiang Yong Min guiping zhou Lei Chen Qun Chen Fei Xu Department of Electrical Engineering Tsinghua UniversityBeijing 100084China State Grid Liaoning Electric Power Supply Co.Ltd. Shenyang 110000China Department of Engineering Mechanics Tsinghua UniversityBeijing 100084China

An integrated heat and power system(IHPS)is a promising approach for alleviating wind curtailment *** an IHPS,the combined heat and power(CHP)plant is the key component,which supplies both heat and electric loads,and couples the thermal system and power ***,existing research commonly ignores or simplifies the internal composition of CHP plants,which could lead to some unavoidable *** paper focuses on the internal composition of CHP plants,and models the physical processes in different components and flexible resources in the CHP ***,a joint dispatch problem of an IHPS with the above CHP plant models is formulated,and an iterative algorithm is developed to handle the nonlinearity in this *** studies are performed based on a real CHP plant in Northern China,and the results indicate that the synergistic effect of different energy resources in the CHP plant is realized by the joint dispatch model,which promotes wind power accommodation and reduces fossil fuel consumption.

关键词： Combined heat and power(CHP)plant CHP unit economic dispatch Integrated heat and power system wind power integration

Cluster of solar active regions and onset of coronal mass ejections

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Science China(Physics,Mechanics & Astronomy) 2015年第9期58卷 95-102页

作者： WANG JingXiu ZHANG YuZong HE Han CHEN AnQin JIN ChunLan zhou guiping Key Lab of Solar Activity National Astronomical Observatories Chinese Academy of Sciences National Center for Space Weather China Meteorological Administration

round-the-clock solar observations with full-disk coverage of vector magnetograms and multi-wavelength images demonstrate that solar active regions(ARs) are ultimately connected with magnetic field. Often two or more ARs are clustered, creating a favorable magnetic environment for the onset of coronal mass ejections(CMEs). In this work, we describe a new type of magnetic complex: cluster of solar ARs. An AR cluster is referred to as the close connection of two or more ARs which are located in nearly the same latitude and a narrow span of longitude. We illustrate three examples of AR clusters, each of which has two ARs connected and formed a common dome of magnetic flux system. They are clusters of NOAA(i.e., National Oceanic and Atmospheric Administration) ARs 11226 & 11227, 11429 & 11430, and 11525 & 11524. In these AR clusters, CME initiations were often tied to the instability of the magnetic structures connecting two partner ARs, in the form of inter-connecting loops and/or channeling filaments between the two ARs. We show the evidence that, at least, some of the flare/CMEs in an AR cluster are not a phenomenon of a single AR, but the result of magnetic interaction in the whole AR cluster. The observations shed new light on understanding the mechanism(s) of solar activity. Instead of the simple bipolar topology as suggested by the so-called standard flare model, a multi-bipolar magnetic topology is more common to host the violent solar activity in solar atmosphere.

关键词： activity coronal mass ejection magnetic fields

Load-Balancing and QoS Based Dynamic Resource Allocation Method for Smart Gird Fiber-Wireless Networks

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Chinese Journal of Electronics 2019年第6期28卷 1234-1243页

作者： XU Siya LI Peng QI Feng GUO Shaoyong zhou guiping DENG Wei LI Yueyue State Key Laboratory of Networking and Switching Technology Beijing University of Posts and Telecommunications Shenyang Electric Power Supply Company State Grid Liaoning Electric Power Company Co.LTd. Beijing Guodiantong Network Technical Co.LTd.

Real-time network resource allocation based on virtualization technology is an important method to solve the solidification problem of Fiber-wireless(Fi-Wi) access networks. To increase the resource utilization and meet the specific QoS requirements of smart gird communication services, a Load-balancing and QoS based dynamic resource allocation method(LbQ-DR) is proposed with three sub-mechanisms. A time-window based substrate network resource update mechanism is designed to describe the realtime resource consumption of substrate networks, which can balance the accuracy of resource status and the complexity of the allocation algorithm.A QoS-based Virtual network request(VNR) sorting mechanism is presented to precisely calculate the priority of VNRs and reasonably sort the incoming services.A load-balancing based resource allocation mechanism is designed to avoid unbalanced resource ***, the channel interference is considered in the cost of embedding and a collision domain mechanism is introduced to decrease interference. Simulation results demonstrate that the proposed method can provide heterogeneous smart grid businesses with differentiated service, improve the utilization and economic benefits of the network and make the network more balanced.

关键词： Load-balancing Quality of Service(QoS) Smart grid communication networks Fiber-wireless(Fi-Wi) networks Resource allocation

Hierarchical Dispatch Method for Integrated Heat and Power Systems Based on a Feasible Region of Boundary Variables

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CSEE Journal of Power and Energy Systems 2020年第3期6卷 543-553页

作者： Tuo Jiang Yong Min Weichun Ge Lei Chen Qun Chen Fei Xu Huanhuan Luo guiping zhou State Key Laboratory of Control and Simulation of Power System and Generation Equipment Department of Electrical EngineeringTsinghua UniversityBeijing 100084China State Grid Liaoning Electric Power Supply Co.Ltd. Shenyang 110000China Department of Engineering Mechanics Tsinghua UniversityBeijing 100084China

Fully utilizing the flexibility provided by a district heating system(DHS)can promote wind power accommodation for an electric power system(EPS).However,for privacy or communication reasons,existing power and heat dispatch methods are not suitable for practical *** this paper,a general math formulation of the hierarchical dispatch method is proposed to coordinate EPS and DHS operators based on the feasible region of boundary variables(FRBV),and a method based on the simplicial approximation approach is proposed to obtain a conservative FRBV approximation of a DHS.A simulation based on a real 41-node DHS is constructed to determine the factors that may impact the boundaries of the FRBV,and then the performance of the simplicial approximation approach is displayed by visualizing the approximation process for the FRBV,and finally three dispatch methods are compared to show the advantages of the proposed hierarchical dispatch method.

关键词： District heating system feasible region hierarchical dispatch method integrated heat and power system simplicial approximation approach

Source-Load Coordinated Optimal Scheduling Considering the High Energy Load of Electrofused Magnesium and Wind Power Uncertainty

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Energy Engineering 2024年第10期121卷 2777-2795页

作者： Juan Li Tingting Xu Yi Gu Chuang Liu guiping zhou Guoliang Bian School of Electrical Engineering Northeast Electric Power UniversityJilin132013China Ministry of Science and Technology Communication State Grid Liaoning Electric Power Co.Ltd.Shenyang110000China

In fossil energy pollution is serious and the“double carbon”goal is being promoted,as a symbol of fresh energy in the electrical system,solar and wind power have an increasing installed capacity,only conventional units obviously can not solve the new energy as the main body of the scheduling *** enhance the systemscheduling ability,based on the participation of thermal power units,incorporate the high energy-carrying load of electro-melting magnesiuminto the regulation object,and consider the effects on the wind unpredictability of the ***,the operating characteristics of high energy load and wind power are analyzed,and the principle of the participation of electrofusedmagnesiumhigh energy-carrying loads in the elimination of obstructedwind power is ***,a two-layer optimization model is suggested,with the objective function being the largest amount of wind power consumed and the lowest possible cost of system *** the upper model,the high energy-carrying load regulates the blocked wind power,and in the lower model,the second-order cone approximation algorithm is used to solve the optimizationmodelwithwind power uncertainty,so that a two-layer optimizationmodel that takes into account the regulation of the high energy-carrying load of the electrofused magnesium and the uncertainty of the wind power is ***,the model is solved using Gurobi,and the results of the simulation demonstrate that the suggested model may successfully lower wind abandonment,lower system operation costs,increase the accuracy of day-ahead scheduling,and lower the final product error of the thermal electricity unit.

关键词： High energy load of electrofused magnesium wind energy consumption thermal power unit wind power uncertainty two-layer optimization

Ready-to-implement low-carbon retrofit of coal-fired power plants in China:Optimal scenarios selection based on sludge and photovoltaic utilization

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Environmental Science and Ecotechnology 2022年第1期9卷 60-71页

作者： Yunchao Xia Jian Deng Bo Hu Qing Yang Jianlan Li Hongqun Gu guiping zhou China-EU Institute for Clean and Renewable Energy Huazhong University of Science&TechnologyWuhan430074Hubei ProvinceChina State Key Laboratory of Coal Combustion Huazhong University of Science&TechnologyWuhan430074Hubei ProvinceChina State Grid Liaoning Electric Power Co. LtdShenyang110006Liaoning ProvinceChina School of Energy and Power Engineering Huazhong University of Science&TechnologyWuhan430074Hubei ProvinceChina

Currently the flexible demand for high proportion penetration of renewable energy depends on coal-fired units(CFUs),and the large-scale phase-out of CFUs in a short time is not realistic in *** to urban expansion,approximately 458 Chinese coal-fired power plants(CFPPs)are now located in *** by space,urban CFUs face difficulty in becoming equipped with carbon capture and storage *** presents a sizeable challenge for the low-carbon transition of urban CFPPs and carbon neutral ***,we present a ready-to-implement method to reduce the carbon emission of CFPPs in limited space:roof photovoltaic-assisted power generation combined with sludge cocombustion for coal-fired power generation systems(PVSCs).We also consider nonurban CFPPs with the method of roof photovoltaic-assisted power generation(PVs)*** on remaining life cycle analysis,we find that the PVSCs could save 28.47 Mt of coal,reduce CO_(2)emissions by 69.76 Mt,treat 125.70 Mt of sludge,and also generate 12.08 billion RMB worth of electricity revenue per *** addition,our scenario analysis shows that PVSCs are more profitable when choosing an urban CFU with a remaining life of more than 12 years and while the sludge treatment subsidy is set at 100 RMB t*** strict and lenient CFU decommissioning policies,CFUs with a remaining life of between 19 and 30 years and between 13 and 24 years should be selected for PVs,***,we conclude that PVSCs can not only generate economic benefits but also facilitate carbon reduction and solid waste treatment.

关键词： Roof photovoltaic Sludge co-combustion CFPPs Decarbonization Optimal emission target selection

Recent studies in satellite observations of three-dimensional magnetic reconnection

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Science China(Technological Sciences) 2007年第3期50卷 380-384页

作者： XIAO ChiJie WANG XiaoGang PU ZuYin MA ZhiWei ZHAO Hui zhou guiping WANG JingXiu LIU ZhenXing National Astronomical Observatories Chinese Academy of SciencesBeijing 100012China School of Physics Peking UniversityBeijing 100871China School of Earth and Space Sciences Peking UniversityBeijing 100871China Institute for Fusion Theory and Simulation Zhejiang UniversityHangzhou 310027China Center for Space Science and Applied Research Chinese Academy of SciencesBeijing 100080China

Magnetic reconnection is a main process converting the magnetic energy into thermal and kinetic energy in plasmas. It is one of the fundamental problems of crucial importance not only to space plasmas physics and space weather studies,such as the solar flare,coronal mass ejections and magnetospheric substorms,but also to the stability analysis in magnetically confined fusion. In general,except for cases with periodical boundary conditions,three-dimensional(3D) magnetic re-connection occurs on magnetic separatrices generated by magnetic nulls. Here we briefly introduce/review the theories and some recent satellite observations of 3D magnetic reconnection. Topics to be further studied are also discussed.

关键词： magnetic reconnection null separatrix separator X-point X-line