bluuebunny/crossref_metadata_2025 huggingface dataset:
Research on active disturbance rejection control of wireless transmission system
Authors: Zhang Zixi , Xiong Hejin , Liu Yushan
Published: February 2021

Wireless transmission technology has attracted much attention at home and abroad in recent years. This paper studies the control of wireless transmission system to make the wireless transmission system have better control response. In this paper, the LCL type electric field coupled wireless power transfer (ECPT) system under three operation modes of open-loop, PID control and active disturbance rejection control (ADRC) is simulated and modeled, and the voltage output waveform of the system under the three operation modes without interference, white noise, pulse interference and change of its own parameters is analyzed. The voltage amplitude difference of LCL ECPT system under ADRC control is less than 50% of PID control, and the recovery speed is more than 1.2 times of PID control. When the system parameters change, the amplitude fluctuation of ADRC is only 8.2% of PID control. The ECPT system with ADRC control has better anti-interference, robustness and response speed.
Fast Multi-Period Security-Constrained Economic Dispatch Based on Deep Neural Networks
Authors: Yang Yan , Du Sijun , Zhu Zhengchun , Xiang Mingxu , Yu Juan
Published: February 2021

Security-constrained economic dispatch (SCED) is one of the most important daily tasks for operators. The scale of security constraints is huge for practically-sized power systems, which makes the SCED difficult or even impossible to be solved. Whereby, the number of active security constraints is relatively small. By eliminating the inactive security constraints, the complexity of SCED can be significantly reduced. Focusing on it, this paper proposes an intelligent framework to accelerate the calculation of SCED without any loss of accuracy. The proposed framework uses a deep neural network (DNN) to reduce the online computational cost significantly by shifting the heavy computation into offline training. More specifically, a DNN is used to extract the feature of SCED, which can effectively pre-identify the active constraints of SCED model. Moreover, an efficient lightweight learning strategy is presented to improve the learning efficiency of the DNN by the feature selection and feature decomposition. The effectiveness of the proposed method is demonstrated in modified IEEE benchmark systems.
Integrated energy system reliability evaluation based on sequential Monte Carlo simulation and fault recovery optimization
Authors: Cui Yanyan , Liu Wei , Su Jian , Yan Tao , Zhang Xianliang , Li Jia , Zhang Lu
Published: February 2021

In this paper, an integrated energy system (IES) reliability assessment method based on sequential Monte Carlo simulation and fault recovery optimization is proposed considering the flexibility of dispatch and the complementary of multi-energy in IES. The reliability evaluation indices of IES are established considering the energy supply and thermal load delay characteristics. An IES failure recovery optimization model is established in which the shutdown loss and the minimum operating cost under the failure scenario are considered comprehensively. CPLEX software is applied to solve the proposed problem in order to obtain the electric and thermal load reduction power and component equipment output. Based on the principle of sequential Monte Carlo simulation, an IES reliability assessment method and process are designed. The analysis of calculation examples shows that the use of failure recovery optimization strategies and consideration of thermal load delay characteristics can effectively improve the reliability of IES.
Functional safety research of battery management system based on risk graph methods
Authors: Chen Mingsheng , Xie Guiting , Ming Zhimao , Liu Guixiong , Li Wei
Published: February 2021

In order to clarify the functional safety integrity hierarchy of the battery management system, this paper uses risk map analysis to qualify the battery management system failure event of an alarm device. The relationship among six risk parameters and four levels of safety integrity are built through specific risk. Thirteen contents are detailed and in according to four risk parameters. The results show that the functional safety outcomes of the battery management system can be classified into seven categories, and safety integrity was determined to be level I using the ten mapped paths in the risk map.
Research on Intelligent Evaluation and Monitoring Method for Cost of Transmission and Transformation Project
Authors: Zhang Xuefei , Yang Lin , Zhang L , Ye J , Zhang C , Zhao D Y
Published: February 2021

With the advancement of fine-grained management of transmission and transformation projects, the construction of an intelligent learning model for the assessment of cost levels is a prerequisite for the implementation of asset management of transmission and transformation projects. To this end, an intelligent assessment and monitoring method for the cost level of transmission and transformation projects is studied. In view of the high-dimensional small sample characteristics of transmission and transformation project cost data, this method constructs cost level evaluation indicators and monitoring error indicators, and proposes a random bit random forest-based transmission and transformation project cost data feature selection method. Based on this, an umbrella-type evaluation monitor was used to build a transmission and transformation project cost level evaluation and online monitoring model. The validity of the algorithm is verified with the actual substation project cost data of a province. The results show that the method proposed in this paper has good feature stability and evaluation accuracy, and can realize online dynamic monitoring of the transmission and substation project cost level.
Attack path analysis of power monitoring system based on attack graph
Authors: Zhang Xiaojian , Wang Qi , Wang Xiangqun , Zhang Run
Published: February 2021

Power monitoring system, as the key to ensure the normal operation of power, is facing huge security threats. The existing protection measures for power monitoring systems mostly start from the aspect of early warning, instead of actual penetration testing of the power monitoring system. To solve this problem, a path analysis method of power monitoring system based on attack graph is proposed to simulate the security test of power monitoring system. In the aspect of route selection, this project quantifies the attack benefits and attack costs to obtain the attack efficiency on each path, and then applies the ant colony algorithm with high efficiency to select the attack path.
Research and Implementation of Automatic Configuration Method for Monitoring Information Table of Smart Substation Equipment
Authors: Jiang Yabin , Qi Jiaen , Chen Yuhong , Liang Yantao , Li Wei , Zhang Fuping , Hu Jiajia
Published: February 2021

Aiming at the problems of low efficiency and difficult configuration of equipment monitoring information in smart substation, an automatic generation method of substation monitoring information table is proposed. By analyzing the configuration file of smart substation, the information of primary and secondary equipment is obtained, and the full model of equipment monitoring information table can be established automatically. According to the classification characteristics of the standard monitoring template, the equipment monitoring information table is automatically generated by association mapping with the monitoring template.
The automatic phase-selective photovoltaic grid-connection system used to control three-phase imbalance of low voltage power grid
Authors: Yi-wen Peng , Si-tong Zhu , Yi-lin Miao , Xinyao Wang , Li-di Wang
Published: February 2021

Three-phase balance degree is an important quality index of power grid operation. Excessive three-phase imbalance will bring serious harm to power grid. To solve the problem of three-phase unbalance of low voltage power grid, this paper proposes and implements a automatic distributed photovoltaic phase-selective grid-connection system based on PLC control. The main functions include: photovoltaic automatic phase-selective grid connection, realization of three-phase unbalanced treatment of low-voltage power grid, low voltage and over voltage treatment of power grid. The main structure includes: monitoring & execution unit, logic control unit and photovoltaic power generation unit. Based on the voltage and load of each phase of the power grid, photovoltaic power generation module can realize automatic phase-selective grid-connection, so as to improve the three-phase imbalance of low-voltage power grid, solve both low voltage and over voltage problems, and realize the comprehensive control of voltage level of low-voltage power grid.
Optimal multi-time scale coordination method for electricity-heating integrated energy system scheduling
Authors: Lin Zhuoran , Wang Shouxiang , Wang Shaomin , Han Aoyang
Published: February 2021

Considering that different energy subsystems have different control characteristics in equipment operations, an optimal multi-time scale coordination method for electricity-heating integrated system scheduling is proposed. It merges three optimal scheduling models based on three-time scales of day-ahead, rolling, and real-time. The coordinated optimization of electricity and heating energies with the same dispatch instruction is fulfilled in day-ahead scheduling. And all feasible scheduling instruction cycles are traversed in the rolling stage to improve the stability of system economic operation. The calculation examples show that the proposed overall strategy for multi-time scale scheduling can achieve multi-energy complementarity, and the optimization results have less deviation from the actual load.
Research on Security Control Scheme of Power Distribution Internet of Things
Authors: Gao Ranxin , Sun Yue , Li Min
Published: February 2021

With the rapid development of the Internet, the process of Power Distribution Internet of Things has been pushed continuously. At present, the number of IoT terminals has increased sharply, and the types are also diverse. Meanwhile, the requirements for the communication timeliness and transmission safety between distribution networks are increasing. The current traditional distribution network structure is unable to properly manage the new terminals. As an emerging technology for information security protection, trusted computing can guarantee a safe and reliable operating environment and management mechanism in the power distribution IoT. Through the optimization of the hierarchical structure of the distribution network and the use of binary trusted security control model, we can build the hierarchical control structure model of the power distribution IoT. It makes the security level of the system has been greatly improved.
Distribution Network Electrical Topology Identification Algorithm Based on Deep Learning
Authors: Qu Ming , Wang Tao , Li Fangshuo , Liu Lina , Li Qilin , Long Hailian , Zhang Yuhang , Xu Jie
Published: February 2021

With the rapid development of smart grids, power data can be collected online and increase in a large amount. Data problems such as missing data, abnormal data have become more and more prominent. Electrical topology is the basis for the implementation of the distribution network. The further development of the smart grid makes new requirements for the accuracy of the electrical topology identification algorithm. Deep learning relies on a large number of data inputs for feature extraction, and shows great tolerance for data missing and fluctuations. This paper proposes a two-channel 1DCNN (One-Dimensional Convolutional Neural Network) model for the electrical topology identification. In this model, voltage and current data are respectively input in each channel for feature extraction with a two-layer stacked CNN. And BN (Batch Normalization) layer and ReLU (Rectified Linear Unit) are added behind each CNN to help convergence. The experiment results show that the proposed model has good accuracy in electrical topology identification.
A Brief Discussion on the Overall Design of High Voltage Intelligent Reactive Power Compensation
Authors: Wu Shitao , Yu Ruirui , Wang Yifan , Wang Dishun , Liu Bo
Published: February 2021

Reactive power compensation can not only improve the voltage quality and the stability of the whole system, but also reduce the loss and improve the economic benefits. With the rapid development of social economy, people put forward higher requirements for the safety, stability and intelligence of power grid operation. At present, there are still some problems in the application of reactive power compensation devices in China’s high voltage distribution network. In this paper, the high voltage intelligent reactive power compensation device is designed from many aspects, and the feasibility analysis is carried out, which provides certain reference for reactive power compensation of high voltage system.
Power Line Communication Challenges in the Energy Internet
Authors: Hao Yan , Zhou Chunliang , Zhang Xudong , Zhao Dongyan , Li Fei , Wang Hongxi
Published: February 2021

Energy Internet is a new hot topic in the research of industry and academia at home and abroad. It is also the development direction of the energy industry, and it is possible to innovate the way of human life. The paper summarized the concept and connotation by surveying the domestic and international development of the Internet of Energy. The information technology architecture of the Internet of Energy is reviewed from the perspective of the integration of energy system and information technology. This article described the characteristics of power line carrier communication, and analyzed the role and status of power line carrier communication technology in the Internet of Energy. The challenges and opportunities that power line carrier communication faces in the Internet of Energy are analyzed. In the end, this paper discussed the future development of Internet of Energy. Through the “Internet +”technology though, it will integrate advanced information technology and energy systems, coordinate multi-energy networks, innovate energy system operation modes, promote industrial upgrading, and generate new economic growth points.
A Two-layer Multistage Expansion Planning Method for Adaptability Enhancement of Distribution Networks
Authors: Feng Liang , Dong Yichao , Wang Shouxiang , Jian Qingzhi , Zhao Long , Liu Rui , Yang Yang
Published: February 2021

With the increasing penetration of distributed generations (DGs) and flexible loads in the distribution network (DN), the existing DN planning methods need an improvement. This paper proposes a two-layer multistage expansion planning method for DN adaptability enhancement, where the optimal construction/upgrade strategy of substations and lines along with the optimal PV configuration strategy are considered. A two-layer adaptive planning model is established and solved by the non-dominated sorting genetic algorithm II (NSGA II). The obtained Pareto-optimal front represents a set of optimal planning schemes meeting the demand of DN economy and adaptability, which is of great significance in theory and practice.
Research on RFID Security Evaluation Method in smart meter
Authors: Wang Rui , Gong Qiujing , Zhen Ke , Hou Xing Zhe , He Min , Wang Ling Yu
Published: February 2021

People pay more attention to the security of RFID of smart meter, this paper establishes the evaluation index framework of RFID security. Then according to these indexes for the evaluation of the RFID system security which is based on fuzzy synthetic evaluation model, all of this is to evaluate the security of RFID system.
Research and Application of Visual Monitoring Technology of Protective Equipment Based on Virtual Model
Authors: Jun Tao , Ming Zhong , Jiangping Wang , Zhihua Wang , Yurong Mao
Published: February 2021

Aiming at the problem of heavy workload and tight time for daily operation and maintenance of smart substations, a visual monitoring technology for smart substation protection equipment based on virtual models is proposed, and a visual monitoring system for protection equipment is established. The article establishes the virtual model of the protection equipment panel, configures the association relationship between the graphic elements in the virtual model and the data set entries of the protection device and the optical fiber link, and establishes the logical operation model of the graphic elements.The visual monitoring system for protection equipment collects the data set entries of the protection equipment and the status values of the optical fiber link data set entries, simultaneously display the status of the primitives in the virtual model of the protection device panel according to the status value of the data set entry of the protection device. The visual monitoring system of intelligent substation protection equipment is applied on-site to verify the effectiveness of the technology.
Fault Location Technology of Transmission Line based on Asynchronous Phasor Measurement from PMUs
Authors: Xiaotao Che , Hangli Jian , Qian Sun , Dong Shang , Wujun Huangfu , Shihui Yang , Weimin Liu , Yalin Li , De Shang , Jiang Li
Published: February 2021

With the continuous expansion of the scale of the modern power system, when the fault occurs at transmission networks, it will have a serious impact on the economy and people’s life. In this paper, a fault location method based on synchronous phasor measurement from the phasor measurement unit (PMU) is proposed in transmission networks. Firstly, the real-time synchronous voltage and current phasors of the transmission lines are measured by the PMU at two buses. Then, the characteristic impedance and propagation coefficient of the line is calculated according to the measurement phasors, and the fault point voltage is listed at both ends of the line. Finally, the fault distance is obtained by solving the complex equation under fault condition at both ends to realize the fault location of transmission networks without branches. Compared with the single-terminal fault location method, the proposed method can eliminate the errors caused by various factors, such as the uneven distribution of capacitance and the uncertain transition resistance. At the same time, this paper uses PSACD software to build a model to verify the effectiveness and superiority of the method.
An efficient vulnerability scanning scheme of smart power grid based on hybrid scanning method
Authors: Wang Qi , Zhang Xiaojian , Yao Qigui
Published: February 2021

As one kind of the industrial control networks, the increasing complexity of the advancing smart grid makes the network security risks greatly increased. Thus, it is necessary to ensure the safety of system. This paper proposed an efficient and low-cost comprehensive vulnerability scanning scheme. Considering the idea of non-intrusive detection without additional flow, the passive detection is proposed associated with PROFINET real-time protocol used in ICS. To reduce the redundant and save resource, fusion detection and connectionless detection are suggested separately adapted to Modbus TCP of ICS which utilizes TCP/IP model. Then passive detection and two activate detections are adopted at different frequencies. The analysis results show that the proposed technique has higher efficiency, lower cost and improves the scanning concealment.
IOC Strategy After Coronavirus and Suggestions for Chinese Oil Companies
Authors: Jia Li , Yun Peng , Xiuling Yin , Xiaowei Song
Published: February 2021

Affected by Coronavirus and low oil price, global oil and gas M&A has been in a downturn in 2020. Countries with oil and gas resource intended to revise fiscal terms, enhancing the economics of producing assets and new developments. Many oil companies have faced severe challenges with impact on Coronavirus and oil price crash. According to IHS expectation, the same tightness will continue into 2021. Learned from international oil companies experience, Chinese oil companies should pay more attention to cost reduction, seize opportunities of the M&A market to get high quality projects, and focus more on energy transition.
Analysis of The Projectile Motion was Blocked in Gun Bore
Authors: Guo Zhaowei
Published: February 2021

To learn the security of projectile was blocked when high-speed movement in gun bore, interior pressure and the movement of projectile were calculated and analyzed under different postulated conditions. Through the analysis of the change in interior pressure after the projectile, the character of projectile was restricted in gun bore during movement and the pressure on both barrel and projectile, also by these to check security in the design of barrel and projectile, and identified the matching problems which needed careful attention in the design processes of both gun and ammunition.
Design and implementation of online uninterruptible power supply system based on STM32
Authors: Zhaowei Liu , Jiapeng Luo , Guorong Zhu
Published: February 2021

The application of microprocessors in automation and industry has become more and more extensive, especially the application of embedded microcontroller technology has promoted the development of UPS design. This paper designs an embedded uninterruptible power supply system with adjustable output based on STM32, and uses PID algorithm to optimize the control strategy. The advantage of this system is that the output is adjustable and has high precision, the circuit structure is simple, the output power efficiency is high, the system is small in size, and the cost is low, while the stability and safety of the system are guaranteed.
Analysis and Quantitative Study of China’s Oil and Gas Uncertainties during the “14th Five-Year Plan”
Authors: Zu-xin LI , Jian-ye LIU , Dong-kun LUO
Published: February 2021

As a mining industry which is vital to the national economy, the oil and gas industry is faced with various uncertainties from the exploration and development at the upstream, refining and production at the midstream to the transportation and sale at the downstream. With the implementation of the “Go Global” strategy of the oil and gas industry and the steady progress of the Belt and Road Initiative, a more comprehensive and accurate identification, classification and quantification of the uncertain factors facing the oil and gas industry is required by the “14th Five-Year Plan”. This paper first identifies and classifies the uncertain factors of the oil and gas industry and then analyzes the difference between those uncertain factors from the domestic and overseas perspectives. Different methods of quantifying the uncertainties are also designed from the three dimensions of resource, technology and economy. Based on the development trend of various factors during the “14th Five-Year Plan” period, this paper predicts the quantitative results of uncertainties in the following 10 years.
A novel Fault Diagnosis Method for Power Transmission Lines Based on Improved Deep Belief Network
Authors: Sun Caitang , Xiao Wei , Li Gang
Published: February 2021

With the rapid development of artificial intelligence technology, the application of deep neural networks to power transmission line fault classification is gaining more and more attention from researchers. In this paper, a novel power transmission line fault classification method based on an improved Deep Belief Network is proposed. The Adam algorithm is used to adjust the learning rate. The convergence rate can be faster and the probability of falling into a local extremum is reduced. This paper uses IEEE 30-bus system as an example for simulation experiment. The electrical parameters and their zero components at the key buses of the power system are selected as eigenvalues. Experimental results show that, contrary to conventional Deep Belief Network method, the improved method has higher classification accuracy and faster convergence. When we increase the noise level of the dataset, the improved Deep Belief Network still has better classification effect.
Experimental Research on the Pipe Grouting Quality Based on Antenna Array Radar
Authors: Jun Xie , Xiaoni Gao , Ning An , Xiaohua Zheng
Published: February 2021

Experimental research on the pipe grouting quality is carried out by detecting the concrete test piece with high-frequency antenna array radar. First, the principle of detecting the pipe grouting quality with ground-penetrating radar is introduced, and then the pipe grouting situation is researched systematically and completely with three methods, including the oscillogram of a single wave, grey-scale image (2D imaging) and slice image (3D imaging) of antenna array radar, and the research results are verified with an indoor test model. The results show that: Pipe can be positioned precisely with antenna array ground-penetrating radar; for failure of judgment of the grouting fullness of metal pipes and the grouting fullness situation of non-metal pipes, the pipe grouting quality can be identified with the oscillogram of a single wave, grey-scale image (2D) and slice image (3D) respectively; Radar detection 3D image can present the position of a pipe in the structure intuitively and accurately, and, the pipe material and the pipe grouting fullness can be judged by comparing the radar detection 3D image and the 3D slice image.
Pushover analysis in different lateral force distribution patterns of bridge piers
Authors: Yang Yaobang , Jiao Daokuan , Song Huaidong
Published: February 2021

Basic principles of pushover analysis method and several different lateral force distribution patterns are briefly described in this paper. A long span concrete continuous rigid frame bridge is taken as an example to carry out the pushover analysis under rarely occurred earthquake. The demand curve and the capability curve are combined to form the capability spectrum to evaluate the seismic performance of the bridge. Analysis results show that different lateral force distribution patterns have great influence on Pushover analysis results.
New infrastructure-oriented power network security supervision innovative mechanism and system architecture
Authors: Liu Chao , Yang Jiaxuan , Qiang Ren , Yuan Linlin , Ju Wei , Xia Yongxin , Mahato Nawaraj Kumar
Published: February 2021

Under the framework of latest digital infrastructure, the application of emerging technologies in the power system has become more in-depth, and the security of power networks has ushered the new challenges. Facing new challenges, power network security inspectors need to keep pace with the times and make innovations in response to the new circumstances. This paper summarizes and analyses the existing network security supervision specifications and practical experience of the State Grid Corporation of China, and combines the laws, regulations, standards and corporate document requirements such as the Cyber Security Law and the Classified Protection 2.0 National Standard, based on the new network security characteristics of the new power digital infrastructure, research the innovative mechanism and system architecture of the network security supervision of power grid enterprises from the aspects of management and technology. Based on the new requirements of Classified Protection 2.0, this paper proposes a network security inspection evaluation system to help grid companies build new lines of network security.
Numerical simulation of in-cylinder combustion characteristics of LNG-diesel dual-fuel engine
Authors: Wang Jun , Chen Jing Sheng , Chen Hao , Hou Yu , Lin Xiao Long
Published: February 2021

Three - dimensional numerical simulation of diesel engine cylinder combustion process was carried out by using computational fluid Dynamics (CFD) software AVL-FIRE. The combustion characteristics of LNG under different ignition diesel ratio, cylinder pressure were studied. Through the simulation calculation of pilot diesel ratio, cylinder pressure, combustion heat release rate, the analysis results showed that the minimum value of pilot diesel ratio was not less than 0.5. During a cycle, there was no cliff-like change in cylinder pressure. CFD simulation has guiding significance for optimizing combustion chamber structure parameters and improving diesel engine performance. CFD simulation is instructive for the optimization of diesel engine performance.
Working Fluids Optimization Based on Economical Performance and Thermodynamic Performance for 350kW ORC System
Authors: Wei Lihong , Jiang Hua , Guo Ruiling , Zhang Haorui
Published: February 2021

This paper established a 350kW level organic Rankine cycle(ORC) system with the 393.15K flue gas as heat source. Nine kinds of working fluids were selected based on comprehensive consideration of thermal physical properties, environmental performance and safety. The optimum one was selected from them by comparing and evaluating their thermodynamic performance and economic performance at different evaporation temperatures. The results show that the thermal efficiency of system using R236fa increased firstly and then decreased with the increase of evaporation temperature, while the exergy efficiency and economic performance increase gradually. The thermodynamic performance and economic performance of others increased with evaporation temperature increasing. When the exergy efficiency was taken as the evaluation index, isopentane was the best working fluid. However, the thermal efficiency, levelized electricity cost(LEC) and discounted payback period(DPP) of the system using butane better than others. Therefore, butane is considered to be the most appropriate working fluid for this system among the nine working fluids.
A high-efficiency micro-grid simulation system based on STM32
Authors: Chen Weixin , Li Xue , Ai Huangze
Published: February 2021

A high-efficiency micro-grid simulation system based on STM32 is designed. The hardware circuit includes two three-phase half-bridge inverter circuits, AC voltage and current sampling circuits, and LC filter circuits. STM32F407 is used as the main controller, and outputs SVPWM waves. The main inverter has low THD when running on its own, so that can stably convert DC power into three-phase AC power. When working in parallel, the system realizes that the output power ratio of the two inverter circuits is adjustable. Through theoretical analysis and testing, the micro-grid has high efficiency, and the circuit also performs well when testing the load regulation rate. In addition, the system uses OLED screens and matrix keyboards to achieve human-computer interaction, and has overcurrent and overvoltage protection functions.
Frequency-Voltage Characteristics Concerned Optimal Dispatch
Authors: Xin Chaoshan , Fu Gaoshan , Meng Xianzhen , Tian Shoutao , Jing Shibo , Zhang Bo , Sun Donglei
Published: February 2021

The rapid development of integrated wind power bring serious challenges to power system operation. In order to address the increasing wind power curtailment problem, the frequency-voltage characteristics concerned optimal dispatch for power system with large-scale wind power integration is proposed in this paper. Through integration of the optimization of frequency characteristics and voltage characteristics into the traditional power system economic dispatch model, the flexibility resources of generation side and load sides in power systems are mobilized to promote large-scale wind power accommodation. The formulated frequency-voltage characteristics concerned optimal dispatch mathematical model is a nonlinear programming model, which is solved by the GAMS platform. The numerical analysis for an actual provincial power grid indicates that the proposed frequency-voltage characteristics concerned optimal dispatch method can promote wind power utilization efficiency and improve the economy of power system operation.
Re-Fracturing Technology Research and Application for Low Permeability Reservoirs in Huabei Oilfield
Authors: Ning Mengmeng , Jia Jiangfen , Guan Shaojie , Wang Peng , Liu Yang , Huang Bohua , Liu Qilun , Kong Weizhong
Published: February 2021

The research on the mechanism of repeated fracturing fractures shows that the pressure drop caused by the initial fracturing fractures and the production activities of the oil layer in the repeated fracturing wells leads to changes in the stress field near the well, which causes the fractures to re-fract during the repeated fracturing process. Combining with the low permeability characteristics of Tongxi fault block reservoir in North China Oilfield, optimization of repeated fracturing parameters and selection of fracturing materials were carried out, and the principle of well selection and layer selection was put forward. The repeated fracturing technology was successfully implemented in the Tong47-43x well and achieved a good oil-increasing effect, which provided important technical measures for the next development of the Tongxi fault block reservoir.
Research on life cycle cost control model of prefabricated building based on system dynamics
Authors: JIANG Jingsi , SUN Shusheng
Published: February 2021

This paper takes BIM as the platform and system dynamics as the research method, establishes the life cycle cost control model of prefabricated buildings, draws causality diagram and flow inventory diagram by Vensim software, obtains the main influencing factors of assembly building cost control, and then gives the cost control measures. In this paper, BIM, prefabricated building and system dynamics are combined to study the cost control of prefabricated building from a new perspective, and reasonable suggestions are given to provide new ideas for promoting the development of prefabricated building in China.
Comparative Analysis of the Construction and Operation Status of Hydrogen Refueling Stations at Home and Abroad and the Classification of Hydrogen Refueling Stations in GB 50516-2010 "Technical Specifications for Hydrogen Refueling Stations”
Authors: Pan Ke , Xu Bingsheng , Wang Bo , Jin Chenhong , Hou Shan
Published: February 2021

This paper reviews and compares the construction and operation of hydrogen refueling stations in China, Japan, South Korea, and Europe, etc. This paper also analyzes the classification of hydrogen refueling stations in the current GB 50516-2010 “Technical Specifications for Hydrogen Refueling Stations” and puts forward suggestions for improvement. Reviews and reflections on hydrogen standardization of China have been made in this paper based on standardization status of hydrogenation station.
A novel composite coupling mechanism base on nested wrapped for dual exicitation IPT system
Authors: You Anhong , Dai Xin , Gao Ruozhong
Published: February 2021

The traditional research based on dual-excitation wireless power transfer system(DES), its theoretical analysis is mostly based on the situation that the mutual inductances of the two primary coils and the secondary coil are equal. When the secondary coil is mismatch, the output powers of the inverters are different due to the difference of the mutual inductances between the two primary coils and the secondary coil, which affects system reliability. This paper designs a coupling mechanism with internal and external nesting, no matter where the secondary coil is located, the mutual inductances between the secondary coil and both the primary coil are the same. Compared with the single excitation system(SES), in the case of the same input voltage, the output power is increased by 4 times, and the stress of the switching component can be effectively reduced under the same output power. The feasibility of the proposed method is verified by simulation and experiment.
Study on novel structure of molybdenum 2-aminopyridine complex: (C5H7N2)2(Mo7O24)(H2O)4
Authors: Liu Haixing
Published: February 2021

A new molybdenum 2-aminopyridine complex (C5H7N2)2(Mo7O24)(H2O)4 is prepared by a hydrothermal reaction and the crystal structure has been determined by means of single-crystal X-ray diffraction. The Mo atom is coordinated by six O atoms. The crystal packing is stabilized by O-H…O and O-H…N hydrogen bonding interaction.
Verification of Rapid Determination of Coal Seam Permeability Coefficient Based on COMSOL
Authors: Bingrui Li , Shubo Li
Published: February 2021

To verify the accuracy of the calculation method based on the indentation-pressure drop method to quickly determine the coal permeability coefficient, this paper simulated the gas pressure change curve of the borehole based on the COMSOL numerical simulation software. The pressure change curve obtained by setting different air permeability coefficients in the simulation software, combined with the rapid determination of the coal permeability coefficient calculation method to calculate the coal permeability coefficient, and the error between the simulated value and the calculated value is compared. The results show that the relative error between the simulated value and the calculated value is -23%~+45%, and the error between the calculated result and the simulated parameter is small, which verifies that the method of quickly determining the coal permeability coefficient based on the indentation-pressure drop method is correct and feasible. The simulation results show that the calculation results of the pressure curve obtained by the short-term simulation and the long-term simulation are basically the same. Therefore, the short-term measurement results can also be used to calculate the coal seam permeability coefficient. The rapid determination of the coal seam permeability coefficient is theoretically feasible.
Synthesis of the VPEG Polycarboxylate Superplasticizer with Controllable Activity and Its Properties
Authors: Chen Wenhong , Deng Lei , Jiang Yu , Li Jianmei
Published: February 2021

This paper focuses on the synthesis of a kind of VPEG polycarboxylate superplasticizer with controllable activity with 4-hydroxybutyl vinyl polyoxyethylene ether (VPEG), acrylic acid (AA) and fumaric acid (FMA) as the main raw materials. Through the experimental results, it can be found that the optimum process conditions are as follows: the water-reducing admixture has ideal fluidity and workability in concrete, with the temperature of 20°C, the reaction system concentration of 40%, the mass ratio of acid to ether of 9.2%, and the initiator and the chain-transfer agent respectively accounting 0.3% and 0.09% of the total mass.
Study on the Preparation and Performance of Hexa-carbon Polycarboxylate Superplasticizer with High Workability
Authors: Deng Lei , Chen Wenhong , Jiang Yu , Li Jianmei
Published: February 2021

In this paper, 4-hydroxybutylvinyl polyoxyethylene ether (VPEG), methacrylic acid (MA) and methylene phosphate (MEPA) are used as main raw materials to synthesize a hexa-carbon polycarboxylate superplasticizer with high workability under the action of an iniator. The test results show that the superplasticizer has high water-reducing rate and good slump-retention, and its workability is greatly increased, which can be used in practical concrete projects that have high requirements.
Preparation of cuprous iodide transparent thermoelectric materials by SILAR method
Authors: Chen Shuai , Zhou Fan , Wei Kun , Chen Naichao , Zhong Minyong , Zhao Jin
Published: February 2021

Thermoelectric generator can obtain electric energy from waste heat, which is one of the best ways to recycle the energy from waste heat. At present, most thermoelectric materials tend to be opaque, so the preparation of transparent thermoelectric materials is one of the research directions of thermoelectric materials. In this work, p-type transparent CuI films were prepared by successive ionic layer adsorption and reaction (SILAR) method. The crystalline structure of the film was determined to be γ-CuI by X-ray diffraction. The surface morphology of the film analyzed by scanning electron microscope was flat. In the wavelength of visible light, the average transmittance of CuI film is 60-70%. The energy band of the prepared CuI film is calculated by the formula to be about 3.04 eV. The results show that the CuI film prepared by the SILAR method has excellent optical transparency.
Noise source identification in indoor substation using a sparse equivalent source method
Authors: Xu Luwen , Yang Bo , Wang Haitao , Zhang Lin , Nie Yaocheng
Published: February 2021

Noise source identification is a key step in the noise control design of the transformer. The sound propagation is influenced by the reverberation effect in the indoor substation, which leads that the traditional method cannot give correct results in such environment. To supress the reverberation effect, a sparse equivalent source method is proposed to realize the noise source identification in indoor substation. This method first establishes the indoor sound transfer function model between the equivalent source surface and the acquisition surface by using wave simulation. Based on the wave simulation and combined with the sound pressure sampling data, the distributed equivalent source is recovered on the equivalent source surface by sparse recovery algorithm, and finally the sound pressure reconstruction on the reconstruction surface is realized. The numerical verification demonstrates that this method is capable of extracting the real noise information in the reverberation sound and giving the real noise source distribution result. This method can be used as an effective method in the noise source identification in the indoor substation.
Research on the effect of UHMWPE cavity protection board on rapid enhancement of wall anti-blast performance
Authors: Wu Xicheng , Tang Baijian , Li Hongming
Published: February 2021

In view of the high cost and self-importance of traditional explosion-proof walls, a fiber composite material cavity protective board made of UHMWPE as a matrix is proposed to protect the walls of general civil buildings to achieve rapid enhancement in response to sudden terrorist attacks. Based on LS-DYNA finite element analysis, the response of the protective board and wall under the impact of the explosion is analyzed. By setting different key parameters such as equivalent weight, burst distance, presence or absence of protective structure, the damage to the wall, the protective effect of the protective board and its own performance characteristics are discussed. The results show that the externally arranged composite material protection board can effectively attenuate and absorb the overpressure and energy generated by the explosion shock wave, and significantly reduce the displacement and deformation of the wall, and it also has excellent performance in its own energy absorption and deformation resistance. But there is a certain safety protection distance under different equivalents.
Study on the occurrence law of gas in Fukang mining area
Authors: Li Chengyu , Zhang Lili
Published: February 2021

Fukang mining area consists of three sections: Urumuqi He-Sigong He, Sigong He-Baiyang He and Baiyang He-Dahuangshan. Typical high-gas mines are taken in the three sections to measure the content of coal seam gas, analyze the occurrence law of gas in Fukang mining area, predict the amount of gas in mining period, and provide the basis for the prevention and control of mine gas.
Separation/enrichment of Nickel(II) using Potassium Bromide-PAN-Phenolphthalein System
Authors: Wen Xinrong , Tu Changqing
Published: February 2021

Separation/enrichment of nickel( II) using potassium bromide-PAN-phenolphthalein system is reported. Various factors affecting the separation/enrichment of nickel( II) are studied, the separation/enrichment of nickel( II) mechanism is deduced. The results show that by contolling pH 6.0, the chelate precipitate of Ni( II)- PAN formed form nickel( II) and PAN could be adsorbed on the surface of microcrystalline phenolphthalein to form liquid-solid phases with a clear interface under the best conditions, while Mn2+, Zn2+, Al3+, Cu2+ and Cd2+ are not adsorbed in this condition. So, the separation of Ni2+ form these metal ions is achieved. The method for the separation/enrichment of trace nickel is established. This method was applied to the quantitative separation/enrichment of trace Ni2+ in synthetic water, and the results are satisfactory.
Simulation optimization research of anti-freezing heat pipe for preheating fresh air in wellbore
Authors: Zhang Yaping , Qu Fangfang , Chen Yao , He Zhiyin , Jiang Haochen , Hao Haohao
Published: February 2021

In order to solve the icing phenomenon of mine wind gap, a physical model of L-type gravity heat pipe was designed in combination with calculation of shaft operating condition, which based on the new idea that geothermal energy of thermostatic formation is used as driving heat source of heat pipe for shaft antifreeze. The numerical simulation showed that the condensation end temperature of the heat pipe could reach 275K. The heat pipe optimization simulation was carried out for the length of the condensation and insulation section of the heat pipe. When the condensing section is 5 m, the effect is the best. The results showed that the temperature at the condenser end of the heat pipe was increased by 275.6K after optimization. The optimized scheme for extracting heat energy from thermostat by heat pipe has a good effect.
Study on the model binary mixtures for actual EPS extracted from the activated sludge in MBR on membrane fouling
Authors: Gao Zhenfu , Wang Dong , Fan Zhiyun , Liu Ying , Wang Zhan
Published: February 2021

In order to find a model solution to simulate actual extracellular polymeric substances (EPS) solution in terms of filterability behavior, a series of experiments were conducted in a dead-end unstirred cell with 0.1 μm polyvinylidene fluoride membranes using single/binary mixtures consisting of sodium alginate (SA), bovine serum albumin (BSA) and humic acid (HA). It can obtain that the presence of BSA and SA is a necessary condition for model the filtration behavior of the actual EPS solution. Meanwhile, compared the actual EPS solution with binary mixtures model EPS solution can find that BSA/SA=140/58.3 and SA/HA=107/28.5 can exhibit the similar filtration behavior as actual EPS, while BSA/HA are far from that of actual EPS solution. The suitable type and combination of simulated solution were determined to improve the consistency with EPS solution in actual MBR system.
Performance and foulants characterization of the industrial integrated membrane system
Authors: Luo Huijia , Cui Yong , Wang Zhan , Guo Yangyang , Wang Xi
Published: February 2021

In order to objectively elucidate the state of the membrane after long-term operation, the performance of a full-scale microfiltration-reverse osmosis (MF-RO) integrated membrane system with production capacity of 20,000 m3/d for wastewater reclamation was evaluated by collecting 10 years performance data. The foulants on 1 MF membrane and 12 RO membranes along the feed channel also were analyzed by membrane autopsy. The results indicate that the water quality of the system can still meet the customer requirements while the mechanical and desalting properties of the membranes were close to the abandoned standards. In terms of foulants distribution, the MF membrane surface was covered by a thick cake layer and the leading RO membrane suffered the highest fouling load. The predominate organic foulants on the membrane surface were protein and polysaccharide, and the main inorganic foulants were Fe and Ca, and their distribution showed two different trends along the feed channel. Regarding bio-foulants, the compositions of bacterial colonies on 12 RO membranes were basically the same, but the relative abundance of the dominant bacteria was different and the microbial diversity increased gradually from the leading element to the terminal one in both the two stages.