bluuebunny/crossref_metadata_2025 huggingface dataset:
Preparation and Properties of Ultra-fine HNS-IV
Authors: Lei Jue , Shi Chun-hong , Wang Pei-yong , Wang Li-xia , Yu Jiang , Chen Dao-ming
Published: June 2023

Ultra-fine 2,2’,4,4’,6,6’- Hexanitrostilbene (HNS-IV) was obtained by HNS-II by vibration cavity comminute. This method uses only alcohol and deionized water, which can be viewed as a green technology. The morphology, particle size, specific surface area, thermal decomposition property and the threshold energy for slapper detonator were compared between HNS-IV and HNS-II in this paper. Results show that after HNS pulverizing, the particle size decreased from 27.18μm to 1.44μm, the specific surface area increased from 0.73m2•g−1 to 9.10m2•g−1. DSC analysis shows that the decomposition peak temperature Td decreases and the melting temperature Tm increases after pulverizing. It is speculated that in the explosive reaction with very high heating rate, the enthalpy of decomposition will be increased by pulverizing, which will be more conducive to detonation growth and explosive reaction. According to the calculation of thermal decomposition kinetics, the decomposition and activation energy Ea of HNS decreases after pulverizing, and the thermal decomposition reaction rate of HNS-IV increases when the temperature is less than 409.6°C. The initiation threshold test of the impact plate shows that the 50% initiation threshold energy of HNS- II is 1.242J, and the 50% initiation threshold energy of HNS-IV is 0.558J, and the initiation threshold for slapper detonatorer is significantly reduced by 55%. This means that the ultra-fine HNS-IV is very suitable as the main ingredient in the booster in the EFI initiation.
Study on Strength and Conductivity of Graphite and Carbon Fiber Concrete
Authors: Zhang Chenglei , Li Yigang , Xue Feng , Mao Shenghai , Jiang Ling
Published: June 2023

In order to study the effects of graphite and carbon fiber on the strength and conductivity of concrete, the compressive strength and conductivity of three types of composite concrete with different mixing ratios of graphite, glueless fiber and rubberized carbon fiber were tested. The results show that the strength of 5000 mesh graphite is weakened, but the ability to reduce resistivity is improved, and the resistivity can be stabilized at about 10 Ω·m. The performance of glue-free carbon fiber in concrete is better than rubberized carbon fiber. Carbon fiber can significantly change the electrical conductivity of concrete without significantly affecting the compressive strength of concrete. In the experiment, the best mixing ratio of concrete was cement 600 kg/m3, water-binder ratio 0.56, and 12mm glue-free carbon fiber content 0.89%. The 28d compressive strength is 36.4 MPa and the resistivity is 12.8 Ω·m.
Research and optimization design of dual-frequency vibration isolation system for helicopter reducer
Authors: Liu Chen , Feng Zhizhuang , Xing Longtao , Yuan Xi , Dai Zhixiong
Published: June 2023

Dynamic antiresonance vibration isolation technology is widely used in the vibration reduction system of helicopters, because its simple structure and high vibration isolation efficiency. In this study, a dual-frequency vibration isolation system with two anti-resonant frequencies has been established, which can adapt to the vibration characteristics of two main vibration frequencies caused by the variable speed of the new high-speed helicopter. The theoretical equation and transmissibility of the dual-frequency vibration isolation system are derived, and the variation law of the weight and other relevant parameters on the vibration isolation performance is explored. The accuracy of the theoretical results is verified by model tests. According to the installation form of the helicopter reducer, the structure of the dual-frequency vibration isolation system is preliminarily optimized, which provides technical support for the design of the vibration isolator of the helicopter with variable speed.
Prediction and Modelling of Plasma Jet Zone Temperature for DC Arc Graphite Purification
Authors: Wang Ying , Zhang Yan , Li Jinmao , Song Chunlian
Published: June 2023

The random forest algorithm was used to analyze the degree of influence of four variables, namely, voltage, current, main gas flow rate, and powder feed, on the temperature of the plasma jet zone of the DC arc graphite purification. The BP algorithm was then used to build a network prediction model. After the training of the network, the validity of the model was verified by comparing the measured temperature values with the predicted results. From the results, it can be seen that the relative error of the prediction results is between -0.3 %and +0.3%, which proves that the built BP neural network temperature model has a satisfactory prediction effect. In addition, this paper also derives specific mathematical expressions based on the threshold and weight values of this temperature prediction model, which can be used to fit the temperature variation curve in the plasma jet region.
Analysis of GMT Composite Material-based Building Formwork
Authors: Luo Dongyan , Zou Xin
Published: June 2023

GMT (Glass Mat Reinforced Thermoplastics) is a new type of composite material made of mica and glass fiber blended into a polypropylene resin substrate, and it is durable, lightweight, high-strength, translucent and easy to install, what’s more, it can be recycled and reused to meet the needs of energy conservation and environmental protection. It is one of the mainstream building formwork materials at present. This paper analyzes and summarizes the performance of the new formwork of GMT, compares it with the traditional mainstream template, studies the problems existing in the development of GMT formwork and conducts corresponding analysis. It is pointed out that through continuous improvement of GMT formwork construction technology and the entire formwork system, its technical advantages can be fully utilized and maintained, in order to provide reference for the further development of GMT new building formwork.
Analysis on Lubrication Performance of Piston Ring-Cylinder Liner based on Numerical Simulation
Authors: Engao Peng , Zhihong Xiong , Zhenkun Luo , Yongyang Zhang , Zhansong Yin
Published: June 2023

This paper mainly studies the tribological performance of friction pairs and poor lubrication during piston movement. Based on the average Reynolds equation and comprehensively considering the variable viscosity and variable density characteristics of lubricating oil, a transient hydrodynamic lubrication model of the piston ring-cylinder liner friction pair is established. By solving the established lubrication model, the lubricating oil film thickness value, friction value and other parameters that can characterize the lubrication performance of the friction pair throughout the cycle are obtained, whilst revealing the surface roughness, lubricating oil viscosity and piston ring barrel surface height. And the influence mechanism of the friction performance of the friction pair is presented on the basis of the previous analysis. The research shows that improving the surface roughness of the piston ring will help to improve the lubrication, increasing the viscosity of lubricating oil will help to improve the lubricating performance of friction pairs and reduce the peak friction at the top dead centre of piston rings and improving the surface texture of the piston rings can reduce the oil film thickness and reduce the friction caused by fluid shear effect in the high-speed region.
Prediction Method for Leakage Probability of Typical Fluid Machinery & Pipeline based on Cloud Model
Authors: Zhao Yuanfei , Ma Jiajun , Chen Guohua , Yang Peng , Sheng Hao
Published: June 2023

Many dangerous chemicals are involved in the operation of fluid machinery, and the leakage of hazardous chemicals could trigger serious accidents, so the leakage probability prediction of fluid machinery and the effective maintenance before the equipment breakdowns are the critical factors in preventing accidents. A leakage probability prediction method based on a cloud model is proposed to aim at the standard fluid machinery with a frequent leakage probability in a chemical industry park. Due to the basic leakage probability of fluid machinery at home and abroad, the index system of leakage influencing factors is constructed and its influence degree is analysed. The modified typical fluid machinery leakage probability is then obtained using the cloud model to eliminate the subjectivity of quantitative results. The proposed method is utilized to estimate the leakage probability of Ethylene pipeline leakage of a pump in 1300# cracking gas compression area. The outcome 4.27 × 10−5 proves that this method can effectively solve the deviation problem in the leakage prediction process of domestic fluid machinery and guide the process of leakage probability prediction or accident prevention.
Design of Intelligent Greenhouse Control System based on MCGS and PLC
Authors: Huang Manying
Published: June 2023

In modern agriculture, intelligent greenhouse systems have become a critical component for optimizing crop growth and maximizing yield. By integrating information technology with the isolation and climate control capabilities of greenhouses, these systems not only enable the automation and intelligence of agricultural production, but also play a crucial role in regulating seasons, protecting crops from extreme weather events, and ensuring optimal growing conditions. In this paper, a comprehensive control system for an intelligent greenhouse was designed, with Mitsubishi PLC and MCGS as the core components, based on the specific growth requirements of plants. The system consists of two main parts: hardware and software. The researchers constructed an advanced control system using a range of sensors and control devices, utilizing a typical PID control algorithm to maintain ideal growing conditions for plants. This research highlights the importance of intelligent greenhouse systems in modern agriculture and presents a promising solution for optimizing crop growth and yield through advanced automation and control.
Research on performance of heat sink with no dielectric copper-aluminum connection
Authors: jinlong Mo , Yiwei Zhu , Yue Zhang
Published: June 2023

Air-cooled copper-aluminum composite heat sink is generally used for heat dissipation of electronic components. If the traditional copper-aluminum connection mode is used, such as welding, copper plugging and locking, bad phenomena such as pores, impurities and interface thermal resistance easily occur on the bonding surface, resulting in decreased heat conduction efficiency, heat dissipation efficiency and lower strength of the bonding surface. Therefore, we introduce a mortise-tenon connected heat sink, and optimize the honeycomb structure of the heat dissipation fin to design a new type of air cooled heat sink with no dielectric copper-aluminum connection. CFD simulation software is used to study the heat dissipation performance of the traditional and new heat sink, and the obtained data are comparatively analyzed to verify feasibility of the process. The result shows that the mass of the honeycomb heat sink is reduced by 37.1%, the surface area is increased by 47.8%, and the heat dissipation performance of the new copper-aluminum heat sink is 60% higher than that of pure copper integrated heat sink. It is concluded that heat sink with mortise-tenon connection has superior performance than traditional integrated air cooled heat sink, and honeycomb heat sink has superior performance than solid plate heat sink.
Laser-based Process Towards Advanced Manufacturing of Metal Alloys
Authors: Gong Na , Liu Hongfei
Published: June 2023

Investigations on application of laser for manufacturing and remanufacturing have been extensively progressed since its advent in 1960. The rapid development of laser technologies in the past half-century has made many laser-based direct-energy processes possible and, nowadays, most of such laser-processing techniques are about entering industrial applications. An application of laser-cladding (LC) for remanufacturing turbine blades can save the cost by over 75%. Laser treatment, on the other hand, making use of direct laser-matter interactions, has been recognized as a green surface-cleaning technique for metal alloys, which may also introduce surface integrity enhancement for additively manufactured alloys. Here, we present and discuss recent progress in laser-based process through a few typical cases that have been recently developed in our group towards advanced remanufacturing of metallic alloys, typically including LC, laser treatment, and laser-shock peening.
Rotor Voltage Compensation Control Strategy of Double-fed Wind Turbine Considering Stator Flux Transient Characteristics
Authors: Liu Yang , Fu Yuan
Published: June 2023

The stability of the grid voltage is directly related to the stability of the DFIG operation, which is related to the topology of the DFIGURE After the grid failure, the rotor current will be too large if the stability threshold is exceeded continuously. The current low voltage control uses additional hardware measures to make the wind turbines survive under the impact of grid voltage drop. Because additional hardware measures will increase the investment of the system, this paper proposes an additional control of the rotor-side converter of the double-fed wind turbine considering the stator flux linkage. The output voltage of the converter is increased through the compensation of additional control to suppress the excessive rotor current. Firstly, the dynamic process of the double-fed wind turbine can be obtained from the relationship between stator flux linkage and rotor voltage of the circuit before and after the fault, and the rotor equivalent circuit is obtained. Combined with the actual control of the rotor converter, the rotor current composition in different coordinate systems is obtained. Compared with the two current components, the equivalent relationship can be obtained to get the transient voltage to be compensated. The rotor converter increases the corresponding output voltage to prevent excessive rotor currents from affecting wind power systems. The simulation proves that the proposed additional control can limit the transient current of the fan rotor in a safe range when the grid voltage drops, which enhances the anti-interference ability of the double-fed wind turbine.
Solar interfacial regeneration performance of different solutions for liquid desiccant cooling system
Authors: Si Laisheng , Li Xiuwei
Published: June 2023

A liquid desiccant cooling system (LDCS) is a promising energy-saving air-conditioning system with the advantages of being driven by low-grade heat and excellent humidity control ability. However, the problems of high energy consumption and low energy utilization efficiency of its regenerator limit its further development. To improve, a novel solar interfacial regeneration (SIR) method is proposed. The method can convert solar energy into heat and locate the heat at the evaporation interface so that the regenerator has high energy utilization efficiency. Experimental studies were carried out on different liquid desiccants. The results show that the thermal regeneration efficiency of this method is 2.6 to 2.9 times that of the conventional thermal regeneration method. LiBr solution has the best regeneration performance, but MgCl2 and CaCl2 are cheaper. Considering energy utilization efficiency and economic cost, the mixed desiccant may be a better choice. These advances could make SIR-based LDCS a potential contender for future air-conditioning systems.
Integrated Energy System Design of Low-carbon City Based on Multi-energy Complementary of Cooling Heating and Power
Authors: Wang Peng , Guan Jun
Published: June 2023

The model of urban integrated energy dispatching system is a mathematical model used to describe the distribution of energy flow in the system, which has the characteristics of high accuracy, strong nonlinearity, and non-convexity. However, in the optimal power flow and other optimization problems, the traditional numerical solution algorithm cannot be directly applied. The strong nonlinearity and non-convexity of the system power flow model bring great difficulties to the solution of the optimization problem. Based on the input and output theory of cooling, heating, and power complementary energy, this paper studies the coupling energy relationship and power flow of various energy devices in an urban multi-source microgrid. It establishes the reliability index of the system energy supply, starting from the integrated energy system structure of low-carbon cities. A bi-level optimization model considering the constraints of energy supply reliability is constructed, which provides a basis for the subsequent establishment of the optimal allocation model.
Maximum power tracking of wave power generation system based on improved particle swarm optimization
Authors: Lan Ying , Gao Guiyu
Published: June 2023

In a wave power generation system, traditional particle swarm optimization (PSO) is prone to premature convergence and local optimal solution when it is used to control the maximum power tracking. Therefore, an improved PSO is proposed, and simulated annealing adaptive particle swarm optimization (SAAPSO) is constructed. The algorithm controls the inertia weight coefficient factor by hyperbolic tangent function and makes the nonlinear adaptive change. Using a linear change strategy to control social learning factors and self-learning factors, a simulated annealing operation is introduced, and a temperature is set according to the initial state of the population. The population is guided to compare the fitness value with the random number in the Metropolis criterion and temperature, and whether a new solution is generated is judged, to improve the problem that the algorithm falls into a locally optimal solution. The simulation results show that the algorithm can effectively prevent the wave power generation system from falling into the local maximum power point, and the maximum wave energy capture ability is significantly improved.
A Multi-objective Control Strategy of the Energy Storage System in Distribution Networks with a High Proportion of Renewable Energy
Authors: Meng Guangze , Sun Yuanyuan , Yu Tao , Wang Chaofan , Sun Kaiqi , An Peng
Published: June 2023

With the development of battery technology and power electronic technology, battery-based energy storage has been widely used in Peak Shaving and Valley Filling frequency and voltage regulation for the power system with a high proportion of renewable energy integration. However, the existing control strategies of the energy storage system (ESS) mostly take peak shaving and valley filling frequency and voltage regulation as a single control objective, causing the rest capacity of the energy storage in the single control working period to be wasted, which significantly reduces the utilization rate and economic benefits of energy storage. How to improve the utilization rate and economic benefits of the ESS while enhancing the support performance of ESS has not received much attention. This paper proposes a multi-objective control strategy of ESS to maximize energy storage’s benefit and ensure the distribution network’s safe and stable operation. First of all, this paper combines the auxiliary compensation benefits of the price system of distributed energy storage power stations and proposes a comprehensive index that comprehensively considers the economy of the ESS and the stable operation of the distribution network to support the evaluation needs of multi-objective control of energy storage. On this basis, this paper predetermines the multi-layer judgment logic for ESS operation control under different operating conditions, divides the ESS into different operating conditions according to the control objectives, and proposes a multi-objective control strategy based on variable droop coefficients. It effectively utilizes the idle capacity of the ESS and achieves an optimized control of energy storage that takes into account both technology and economy. The simulation verification based on the energy storage model built in Matlab/Simulink is conducted to validate the effectiveness of the proposed ESS multi-objective control strategy.
Single phase to ground arcing fault identification based on wavelet packet energy
Authors: Yang Jiakui , Wang Tao , Jin Zonghao
Published: June 2023

With the increasing proportion of cable lines in the distribution network, the capacitance current in the system increases, which leads to the single phase to ground arcing fault in the distribution network. However, at present, there is less research on single phase to ground arcing fault, and the type of grounding fault is always assumed to be metallic or resistive grounding, and the arcing ground fault is not identified in time, which leads to further expansion of the fault. In this paper, the transient simulation analysis of a single phase to the ground is carried out, and a new method to distinguish arcing ground fault from metal grounding fault using wavelet packet energy is proposed, which solves the problem of fault type identification. Through a large number of simulation data analyses and practical verification, it is shown that the method is not affected by the time of fault occurrence and neutral grounding mode, and has a strong anti-interference ability and high reliability.
Effect of Fuel Utilization on Tri-reforming-SOFC Systems with Different Heat Management Strategies
Authors: Wang Xuan , Hou Ruijun
Published: June 2023

Four tri-reforming-SOFC system configurations are built with different off-gas recirculation methods (anode off-gas recirculation and burner off-gas recirculation) and different reformers (with heat exchange and with oxygen injections) to improve heat management. The systems are modeled to explore the effects of fuel utilization. It is found that the recirculation type mainly affects the maximum temperature in the reformer while the reforming type mainly affects the methane conversion. The max temperature gradient in the stack increases with fuel utilization in configurations C and D, therefore high fuel utilization should be avoided in these two configurations. The system electric efficiencies are enhanced compared with the stack electric efficiency. AOGR and reformer with heat exchange are preferred to enhance the system’s electric efficiency, and configuration A exhibits the highest system electric efficiency.
Causes and Prevention of Photovoltaic Module Hot Spot Effect
Authors: Zhang Xiuqi , Yuan Shuai , Wang Qi
Published: June 2023

The photovoltaic module is the basic link in the photovoltaic power generation system, which has an important impact on the economic operation of photovoltaic power plants. Hot spot effects account for a large proportion of photovoltaic module failures, so it is of engineering significance to study them and put forward suggestions for fault prevention. Firstly, this paper briefly introduces the composition of photovoltaic power generation system and the structure of photovoltaic modules then analyzes the working process and typical models of photovoltaic modules as well as the causes of the hot spot effects of photovoltaic modules. Finally, it puts forward some measures to prevent faults to improve the operational reliability of photovoltaic modules.
The Daqing Oilfield Sazhong Development Zone with the Gas-oil Ratio
Authors: Wan Jianrong , He Jingang , Chen Qinan
Published: June 2023

In the late stage of super high water cut development in the Sazhong Development Zone, the oilfield development rules have changed, showing a significant increase in the production gas-oil ratio. To study the factors and laws of production gas-oil ratio change, laboratory research on oil/gas/water high-pressures physical properties, a field test for single layer development, and theoretical calculation of modified oil-gas ratio were carried out. The results show that partially dissolved gas can be obtained from saturated gas crude oil by injecting water or polymer solution. In the ultra-high water cut period, especially when the water cut rises to 95%, the production gas-oil ratio will rise sharply due to the influence of gas production in water. At the same time, the ground saturation pressure difference is also an important factor affecting the production oil-gas ratio and recovery factor. Therefore, in the process of analyzing the production gas-oil ratio, it is necessary to study the influence of the ground saturation pressure difference and the dissolved gas-water ratio, especially in the ultra-high water cut stage and chemical flooding stage.
The dynamic wireless charging system of suspension inspection robot
Authors: Deng Siming , Liu Feifei , Zhong Xiangxing
Published: June 2023

Intelligent inspection robots can monitor the behavior of poultry in real-time according to the production management needs of standardized poultry breeding, and gradually replace the method of artificial inspection to become a new method for farm detection. The good performance of its power system is the basis for ensuring the extension of the inspection cycle. In a humid environment, the traditional power supply method will cause the wear, leakage, and heating of the wires, which causes the safety of the farm to be guaranteed. Therefore, this article designed a suspension inspection robot system with dynamic wireless charging functions. It can run steadily at high temperatures, high humidity, and high dust environment, and use radio energy transmission technology based on induction coupling principles to move the inspection robot to dynamic wireless charging. The coupling quality is used to improve the transmission efficiency of the system, and it provides a reference for the design of the wireless charging coupling device of the inspection robot in the future.
The Power Quality Monitoring Method of Intelligent Power Distribution Cabinet
Authors: Gao Qiang , Yuan Feng , Li Bing , Jiang Zhunan , Ye Peng , Dai Jicheng , Pan Fenghou , Li Zailin , Pan Jiayu
Published: June 2023

To improve the authenticity of reconstructed signals in power quality disturbance detection, an improved wavelet denoising method based on a coquantum-particle swarm is proposed to solve the problem that parameters in the traditional wavelet function are not easy to obtain, and a power quality disturbance detection framework is constructed. Simulation analysis verifies that the proposed method can effectively improve the disturbance detection performance compared with the traditional method. The reconstructed signal is closer to the original signal, which verifies the effectiveness of the proposed method.
A Non-invasive Load Identification Method Based on V-I Trajectory Mixing Feature
Authors: Song Yang , Zhang Ruoyuan
Published: June 2023

Non-invasive load decomposition technology is an important part of the smart grid technology system. Aiming at the problem that traditional methods cannot accurately identify household loads containing high-order harmonics, a load identification method based on V-I trajectory matrix-power and high-order harmonics multi-feature fusion was proposed. First, the V-I trajectories, power characteristics, and harmonic characteristics of 11 typical household loads are analyzed, and a hybrid feature matrix construction method based on pixel image transformation is proposed. Through binary coding transformation, the power and high-order harmonic characteristics of the load are fused with the basic V-I pixel trajectory, enriching the characteristic information of the sample. Second, a recognition algorithm based on Gaussian Mixture Model (GMM) and Support Vector Machine (SVM) is established, and the probability distribution of the two algorithms is fused to generate the final recognition result. Finally, the Plug Level Appliance Identification Dataset (PLAID) was used to verify the proposed method, and the accurate identification rate of various household loads was over 93%. Experimental results show that the proposed method can accurately identify household load, including high harmonic load.
Typical Failure Causes of Photovoltaic Module
Authors: Zhang Xiuqi , Wang Liqiang , Wang Qi
Published: June 2023

The application of new energy such as solar energy is a measure to promote the green and low-carbon transformation of energy, and photovoltaic power generation has been widely developed and utilized. The photovoltaic module is an important part of photovoltaic power generation, which is crucial to the economy and reliability of power generation. This paper introduces the current situation of photovoltaic power generation, explains the structure and power generation principle of photovoltaic modules, counts the typical failures of photovoltaic modules, and analyzes the causes of the failures, which can provide a reference for the operation and maintenance of photovoltaic power stations.
Comprehensive Recovery of a High-sulfur Copper-gold Ore in Shandong
Authors: Ji Qiang , Li Guangsheng , Zhu Xingfu , Gao Tengyue , Qin Guanglin , Qin Xiangwei , Wang Junjie , Zhang Xiaoguang
Published: June 2023

The raw gold grade of a mine in Shandong is 1.42 g/t, and it is accompanied by copper and sulfur minerals, and the embedding is closely related, so it is difficult to obtain the ideal index using the original flotation process. In order to realize the effective recovery of gold, copper, and sulfur, the test study of mixing-separation flotation and priority flotation is carried out. The results show that the mineral is more suitable for the beneficiation process of mixing-separation flotation. The recovery rate of gold, copper, and sulfur is 70.42%, 93.58%, and 68.85%, and the recovery rate is 22.89% higher than the priority flotation. The produced copper and gold mixed concentrate and sulfur concentrate can be directly sold to realize the effective recovery of gold, copper, and sulfur.
Application of well testing technology in YT1 condensate gas well
Authors: Zhang Jiping
Published: June 2023

YT1 is an offshore condensate gas well. During gas testing, well testing is carried out to determine the productivity of the well. The productivity equation is established by modified isochronal well testing. The flow pressure change trend with production under different working systems is compared with the dew point pressure of the gas reservoir under the condition of retrograde condensation to determine the reasonable production differential pressure to avoid the abnormality of productivity equation and calculate the open flow and the reasonable working system. Formation parameters are calculated such as formation pressure, skin factor, effective permeability, flow coefficient, and test radius through pressure build-up test while reservoir type, boundary, and dynamically controlled reserves are determined. According to the analysis results of productivity and reserves, considering the investment cost of offshore gas reservoir development, storage, and transportation, we can comprehensively evaluate the economic rationality of YT1 well construction and production, providing reference experience for improving the benefits construction and production level of the offshore condensate gas reservoir.
Development and experimental study of a long-time monitoring system for mine water damage electrical information
Authors: Wang Yue , Wang Pengyu , Yi Xiaofeng
Published: June 2023

The change of mining stress often accompanies coal mining; these changes will affect the underground pressure water, destroy its original equilibrium state, increase the possibility of underground pressure water upward gushing, and then lead to the occurrence of mine water inrush accidents. A long-time monitoring system of mine water damage electrical information is developed to realize the long-time monitoring of mine underground pressure water. Based on the principle of resistivity tomography, this paper analyzes the method’s feasibility in inferring different geological distributions. Secondly, the long-time monitoring system of mine water damage electrical information is introduced. Finally, the stability and reliability of the instrument were proved by the simulation experiment, and the instrument was installed in the 17-33200 working face of Ping Coal No. 10 Mine, Pingdingshan City, Henan Province, China, for actual measurement to obtain the electrical information data of working face floor.
Load Simulation Analysis of 1.5 MW Horizontal Axis Wind Turbine
Authors: Bai Dongxiao , Han Shichang , Zhao Zhenzhou
Published: June 2023

Wind turbine blades are subjected to a variety of loads in actual operation, which are prone to deformation and cause the strain and stress concentration of the blade structure, thereby affecting the safe operation of the wind turbine and the service life of the blade. Therefore, a numerical simulation study on the coupling of wind turbine blade loads with their displacement, deformation, and stress is carried out. The results show that at the same wind speed, as the wind turbine speed increases, the pressure on the windward side of the blade increases, the negative pressure on the leeward side decreases, the pressure difference between the two sides increases, and the maximum pressure is distributed in the tip of the blade; the blade is under different loads, among which the aerodynamic load is the main factor affecting blade deformation and stress generation. The maximum deformation of the blade appears in the direction of the swing.
Variable operating conditions characteristics of circulating wheel dehumidification air conditioning system
Authors: Du Zhehua
Published: June 2023

For its efficient application of low-grade energy, the circulating wheel dehumidification air conditioning system has received a lot of attention and research in response to the shared challenges of environmental protection, energy conservation, and low carbon. Desiccant wheel dehumidification air conditioning systems can recycle waste heat as a desiccant wheel regeneration heat source and improve air quality, which is expected to achieve low energy consumption and high-efficiency dehumidification. The desiccant wheel dehumidification air conditioning system is divided into a treatment air channel and a regenerative air channel. Treated air is directly sent to the air conditioning room after dehumidification and cooling, and regenerative air is directly discharged to the outdoors after the completion of regeneration. Therefore, a new type of recirculated desiccant wheel dehumidification air conditioning system is established. In this paper, the experimental study of the circulating regeneration wheel dehumidification air conditioning system is carried out. Dehumidification characteristics under variable working conditions are quantified and studied. Compared with the water cooling unit, the dehumidification rate of the new circulating wheel air conditioning system is improved effectively. The effects of different treated air temperatures (28 °C–40 °C) and treated air relative humidity (50%–85%) are obtained. The experiment shows that the proposed air conditioning system can effectively improve the dehumidification rate compared with the conventional direct condensation of seawater. Under the same circulating shunt coefficient, the system dehumidification rate increases gradually with the increase of the temperature and humidity of the treated air and the temperature of the reclaimed air. The dehumidification rate has an optimal value, and the corresponding optimal circulation shunt coefficient is 50%–75%, which decreases with the increase of the temperature and humidity of treated air and increases with the increase of the temperature of regenerated air.
Short-term wind power prediction based on DWT-PSO-LSTM
Authors: Zong Changsheng , Gao Qingzhong , Wu Shuai
Published: June 2023

With the “carbon peaking and carbon neutrality” target, quite a few people are focusing on the development of renewable energy, especially wind power, which is the largest source of renewable energy generation and is still expanding. In aiming to make the wind power forecasts more accurate by limiting the errors between the predicted and actual values, a model combining Particle Swarm Optimization, Discrete Wavelet Transform, and Long Short-Term Memory (DWT-PSO-LSTM) is developed to predict the wind power for short periods. First, the wind power is decomposed and normalized by DWT. Then, each decomposition result is input into LSTM prediction, and the model with the good result is obtained by finding the number of nodes and learning the efficiency of the best LSTM through PSO. Finally, the full prediction results are output and then all components are summed. Simulations using open wind power data from Yalova province, Turkey, indicate that the model advanced in this article can reduce the prediction errors better than other models.
Viscosity, activation energy, and CO2 diffusion coefficient of non-aqueous solutions of 3-methylamino propylamine (MAPA)/3-dimethylamino-1-propylamine (DMAPA) with polyethylene glycol (PEG200)
Authors: Zhao Yuetong , Jin Fazhou , Sun Yanli , Wang Lemeng , Fu Dong
Published: June 2023

In this paper, viscosity (η) of 3-Methylaminopropylamine (MAPA)/3-dimethylamino-1-propylamine (DMAPA) with polyethylene glycol (PEG200) was detected over the range of (from 303.2 K to 323.2 K) temperature with amine mass fractions in the range of (from 0.30 to 0.60) at atmospheric pressure. The dependence of η on temperature and mass fractions was clarified. On the experimental basis, the activation energy (Ea) and CO2 diffusion coefficient (D
CO2) in MAPA/DMAPA-PEG200 non-aqueous solutions were deduced.
Liquid Level Measurement and Control in High Temperature and High-pressure Environments of Nuclear Power Plant
Authors: Hu Yanjun , Xu Tianxiang , Gan Changxian , Zhu Qinglian , Liu Shengzhi
Published: June 2023

There are many pieces of high-temperature and high-pressure system equipment in nuclear power plants, such as deaerators, high-pressure feedwater heaters, steam-water separation reheaters, etc. The media parameters in these systems and equipment are high and the working conditions are complex. It is necessary to solve the above problems by adopting multi-channel averaging, increasing the slope of the condensing line, and separating the sampling ports of multiple channels. After practical verification, the above solution can effectively solve or reduce the above problems, which can provide a reference for the liquid level measurement and control in subsequent similar high-pressure and high-temperature environments in nuclear power plants.
Waste Heat Recycling Absorption Refrigeration Circulation System
Authors: Wang Xinjun , Zhou Qingyang , Cai Yanping , Yu Xinyu
Published: June 2023

To maximize energy use, this paper designs a lithium bromide absorption refrigeration system that is used to recycle and use low-temperature energy and industrial residual heat. Firstly, the mathematical model of the system is established using the lithium bromide aqueous solution status equation and the equation of the state of water and steam to obtain the state parameters in the thermodynamic calculation process of the system. Secondly, according to the principle of mass economy, energy saving, and heat transfer, the thermodynamic parameters of each process of the system are obtained to assist the design of the system. Finally, the influence of some key parameters on the system is simulated and analyzed to obtain the optimal parameters which can make the system recovery efficiency the highest. The simulation results show that the system conceived in this article can efficiently recycle waste gas and achieve the purpose of refrigeration. Therefore, it has a certain value of popularization.
Structural Optimization and Simulation of a Magnetic Leak Detection Device for Streak-like Defects in Oil Pipes
Authors: Zhou Feng. , Zhang Dali. , Zhao Han. , Hu Heng.
Published: June 2023

Striped defects are a common type of defects in oil pipelines, divided into horizontal and longitudinal stripes, and it is difficult to accurately quantify the results of conventional pipeline leakage magnetic detection to correspond to the type of defects and their extent. In this paper, a new type of oil pipe non-destructive testing equipment is proposed and designed based on the principle of magnetic leakage detection using three-dimensional finite element simulation, and the magnetic field distribution inside the equipment is simulated using ANSYS finite element analysis software to provide original data reference for the development of the new equipment.
An Online Junction Temperature Monitoring Method for SiC MOSFET Based on Drain-source Voltage Change Rate During Turn-on Transient
Authors: Guo Yahui , Sun Peng , Li Huanlin , Cai Yumeng , Zhao Zhibin
Published: June 2023

This paper analyzes the turn-on transient of silicon carbide (SiC) metal oxide semiconductor field effect transistor (MOSFET) based on the basic physical equation, and the analysis model of drain-source voltage change rate (dv
ds/dt
) during turn-on transient is derived. The change rule of dv
ds/dt
of SiC MOSFET during turn-on transient and its temperature-dependent characteristics are studied, and the calculations generally fit the measurements well. Experimental results show that the magnitude of turn-on dv
ds/dt
increases with increasing temperature and exhibits good linearity. The influence of driving conditions on the temperature dependence of the turn-on dv
ds/dt
is also analyzed through the model, finding that the temperature sensitivity can be improved by reducing the driving forward bias voltage and increasing the driving resistance. Finally, the online junction temperature monitoring experiments are used to verify the accuracy and effectiveness of the proposed method.
Operating flow rate prediction of H4 condition in NPP
Authors: Deng Chunyin , Chen Guoxing , Liu Shengyong , Yao Zhimeng , Zhang Wenli , lu Zhuang , Wu Shuhui
Published: June 2023

In this study, we present a method to predict the working volume flow rate of H4 conditions in nuclear power plants. The working flow rate can be predicted using the intersection points of the two curves on a hydraulic characteristic diagram using the quantitative relationship between fluid flow and pipe resistance under the turbulence model and the hydraulic performance characteristics of the hydraulic equipment. The H4 condition volume flow rate of a power plant is predicted in this research using this method. The findings demonstrate that the method can substitute the actual H4 working condition test to lower operating costs while having high accuracy and little deviation. This approach can be usefully expanded to cover more comparable circumstances.
Research and implementation of debugging method of digital phase-locked loop
Authors: Li Yonggang , Li Yingtao
Published: June 2023

This paper studies the commissioning method of phase-locked loops to enable the phasemeters to achieve the required frequency and phase accuracy. The influence of different phasemeter structures on performance is explored. Through theoretical analysis and experiments, the debugging process of the phase-locked loop is clarified, which can meet its basic indexes, especially frequency and phase accuracy, and is optimized for its traditional structure.
Segmented sensor blockchain based on state and block compression
Authors: Wang Xinhong
Published: June 2023

In the sensor blockchain network, sensors need to collect data continuously and upload it to the blockchain network for verification of data integrity. The deployment of smart contracts on the chain can be used to authenticate data visitors. Historical data is valuable for data visitors, but it is useless for sensor nodes that can continue to link data only with current information. With the passage of time, the data of the sensor blockchain network will continue to grow. A node data storage mode that can adapt to the continuous expansion of the blockchain scale is needed, which can encourage nodes to join the network to participate in consensus and jointly maintain the security of the blockchain data. This paper provides a segmented storage solution based on state and block compression for sensor device nodes with limited storage capacity. After experimental verification, this scheme can significantly reduce the storage cost. It allows nodes to use blockchain for a long time in sensor blockchain networks with large transaction volumes and a large number of smart contracts and allows new nodes to be deployed faster.
Parameter Estimation and Mutual Coupling Self-Calibration with Orthogonal Polarization Sensitive Array
Authors: Qu Zhiyu , Zhang Xin
Published: June 2023

In order to address the mutual coupling impact with orthogonal polarization sensitive array, the mutual coupling self-calibration strategy is suggested in this study. Firstly, the mutual coupling properties are used to modify the steering vector of the array. By transforming the matrices, the properties of the polarization and direction-of-arrival (DOA) are isolated from the mutual coupling coefficients. Then, using the rank deficit matrix approach, the estimated the polarization properties and DOA values of the incoming signal are ascertained. The eigendecomposition of the transition matrix utilizing the modulus restrictions is then used to get the mutual coupling coefficient. The technique may be used to produce high-precision results of the mutual coupling coefficient when there is a substantial gap in the power of the signal sources. The outcomes of the simulation demonstrate the viability of the advanced method used in this work.
Magnetic Field Downward Continuation Iterative Method Based on Low-pass Filter
Authors: You Guanjie , Yu Ziqiang , Wang Ze , Pan Mengchun , Xu Yujing , Zhang Qi
Published: June 2023

Magnetic field downward continuation is an important technique for expanding geomagnetic database, which can separate superimposed anomalies and enhance the resolution of local anomalies. However, the adaptability of the fixed filter operator of the existing downward continuation algorithm to the wavenumber domain frequency component of the observed data is not good enough, which leads to the poor applicability of the algorithm, resulting in poor applicability of the algorithm. The downward continuation iteration method based on a low-pass filter is proposed in this paper. First, the residual terms based on the remainder of the first and second vertical derivatives are constructed by using the stability of upward continuation; Secondly, the upward continuation low-pass filter operator, single parameter low-pass filter operator, and two-parameter low-pass filter operator are designed, and the effects of their filtering characteristics on the continuation stability are compared. At the same time, the cut-off frequency and order of the filter operator with parameters are optimized to update the iterative value. Simulation and experimental studies are carried out under different field source depths. Simulation results show that the convergence performance of this method is better when dealing with shallow source field, and the continuation accuracy is improved by 15%–25%. The stability and effectiveness of the magnetic field downward continuation method are verified by the measured data.
A six-digit digital attenuator working in the Sub6G band
Authors: Liang Peijie , Zhang Miao , Wang Peng , Li Chengyu
Published: June 2023

A high-performance 3–6 GHz monolithic digital control attenuator chip is designed by using a 0.25 μm GaAs pHEMT process. The circuit adopts a cascade structure of 6 basic attenuation units, and 64 attenuation states are formed by controlling the on-state combination of different attenuation bits, and the attenuation structure connected in parallel to the attenuation resistor is given. The main simulation results show that the designed digitally controlled attenuator takes 0.5dB as the attenuation step, and the maximum attenuation value is 31.5 dB, an insertion loss of less than 2.55 dB, a return loss better than -15 dB, an attenuation accuracy of less than 0.5 dB for all states, an additional phase shift of less than -5°, a root mean square error better than 0.23 dB of attenuation amplitude, and chip size of 1.88 mm×1.0 mm.