bluuebunny/crossref_metadata_2025 huggingface dataset:
Oyster mushroom house conditions classification using K-Nearest Neighbor
Authors: Wiryawan I G , Mulyadi E , Choirunnisa S , Destarianto P , Agustianto K
Published: February 2022

Internet of Things devices that were implemented to support condition monitoring and control systems in mushroom houses get a lot of temperature and humidity data from mushroom houses. The large number of temperature and humidity data can be used as the variables or indicators that affect mushroom production. Temperature and humidity data can be classified based on the production of mushrooms produced in one house or mushroom houses. This study aims to determine the classification of temperature and humidity data in mushroom houses based on mushroom production. The method used is a data mining approach based on the K-Nearest Neighbor. This research begins with determining the variables from training data or training data, taking testing data, then the testing data is reprocessed based on the K-Nearest Neighbor method with training data. Finally, evaluation of the method used was carried out by calculating the accuracy value. As a result, the accuracy of the K- Nearest Neighbor method was about 89%. These results are expected to be used to forecast the yield of mushroom production for future research. The forecast can be seen from the pattern of temperature and humidity data that is formed based on a certain period of time.
RETRACTED: Surface Modeling Vehicle for Shrimp Ponds using Artificial Neural Network
Authors: Destarianto P , Agustianto K , Rosdiana E , Wiryawan I G , Mulyadi E
Published: February 2022

The worldwide frozen shrimp trade market in 2018 was recorded at the US $ 17.2 billion or around Rp.232.2 trillion. Indonesia is one of the principal exporters of frozen shrimp in the worldwide market. In light of this information, shrimp cultivating is a promising area, yet shrimp cultivating is particularly controlled by water quality. Water quality in shrimp cultivating consistently changes. Many variables impact changes in water quality (shrimp biomass, PH, and temperature). These components in the water should be inside the standard limit rank. Thusly, to accomplish the creation effectiveness of the shrimp business, it is important to robotize water quality control. This study aims to develop Surface Modeling Vehicles (SMV) for Shrimp Ponds utilizing an Artificial Neural Network. The test outcomes show an exactness pace of 94%, the expectation is that the instruments created by the exploration will want to acknowledge exact Vename Shrimp cultivating, so creation proficiency and expanded shrimp creation can be accomplished.
RETRACTED: Adaptive Temperature And Humidity Control System on Kumbung Mushroom using Fuzzy Neural Network Algorithm
Authors: Hartadi D R , Agustianto K , Destarianto P , Wardana R , Kustiari T , Wiryawan I G , Mulyadi E
Published: February 2022

National mushroom production in 2018, 2017, 2016, and 2015 were: 31052, 3702, 40915 and 33485 tons. Mushroom cultivation, especially oyster mushrooms, has the potential to be developed more widely in Indonesia because it has economic value and is environmentally friendly. However, the cultivation of oyster mushrooms has challenges. The challenge that arises in the cultivation of oyster mushrooms is to grow well at a temperature of 16 – 30 °C and a relative humidity of 80 – 95%. Environmental conditioning carried out by farmers on average through spraying water in mushroom kumbung manually. The use of manual methods requires high human resources, besides that it is not effective and efficient. This study aims to develop an Adaptive Temperature and Humidity Control System on Kumbung using Backpropagation Neural Network, where to determine the temperature and humidity the system will evaluate the readings of several sensors at once. The system developed is an adaptive system with an accuracy of 97%, so it is can be used to increase the precision of mushroom cultivation, so that production efficiency and increase in mushroom production can be achieved.
Preface
Authors: Tang Wenzhe
Published: February 2022

EEEP (International Conference on Energy Engineering and Environmental Protection) is an annually held conference for all researchers home and abroad since 2016, aiming to provide a good platform for scholars and researchers in the field of energy and environmental protection to discuss the latest developments and achievements, work out good solutions, and make contributions.

The Sixth International Conference on Energy Engineering and Environmental Protection (EEEP2021) was planned to be held in Sanya, China on November 16-18, 2021. Due to the epidemic of COVID-19, the event had to be changed from onsite to online during November 16-17, 2021 for academic exchanges & discussions.

List of Technical Program Committee, Special Session on Intelligent Integrated Energy Systems are availbale in this pdf.
Demand response strategy for TCLs considering consumer utility
Authors: Shen Li , Wang Feng , Shi Heqing , Gao Qiong , Wu Qiong , Yao Yu
Published: February 2022

With the higher share of renewable energy, the flexibility of the power system needs to be improved. In recent years, the loads on the demand side can provide flexibility with the development of demand response technology. Thermostatically controlled loads (TCLs), as a kind of large-scale flexible load, have been a significant demand response resource. In this paper, a demand response strategy for TCLs considering consumer utility function is proposed. Firstly, a utility function is modeled to estimate the utility of TCLs. Then a model for estimating the potential of TCLs is built. On this foundation, the power system operators (PSOs) sort TCLs by consumer utility. TCLs with lower consumer utility will be called first. The study case adopts realistic data of an eastern city in China, which verifies the effectiveness of the proposed strategy.
An economic assessment method for flexibility enhancement technologies of thermal power plants
Authors: Wang Jianbo , He Xiangdong , Jia Haibing , Le Ying , Sun Xiaocong , Guo Chao , Xu Kangxuan
Published: February 2022

High-level renewable energy integration imposes significant uncertainties into power systems. The negative peak load regulation (NPLR) and frequency regulation (FR) are needed for the security of the system’s operation. Thermal power plants are urgent to carry out flexibility enhancement to provide NPLR and FR. However, there are diverse flexibility enhancement technologies to be chosen. This paper proposed an economic assessment method of flexibility enhancement technologies to conduct thermal power plants to choose the best scheme. Firstly, the framework for the economic evaluation is proposed. The various flexibility enhancement technologies are classified based on the revenue model. Then, the revenue function of NPLR and FR are formulated under the ancillary service market. Finally, the economic indexes, such as, the internal rate of return (IRR), net present value (NPV), and payback period are calculated. The proposed methods are validated using a 200 MW power unit with a condensing steam turbine. The results demonstrated the effectiveness of the proposed framework.
Regulation capacity evaluation for air conditioners considering operating status and occupant comfort
Authors: Yang Xuan , Xu Xianghai , Yin Jianbing , Liu Jian , Wei Wei , Zhang Zhipeng , Chen Zhiyuan , Lu Haibo , Qi Taoyi , Xie Kang
Published: February 2022

In recent years, the load peak-valley difference is increasing rapidly and needs more regulation capacity to reduce it. However, traditional generating units are phasing out for low carbon goal and cannot provide enough regulation capacity for the power system. Besides, Air conditioners (ACs) account for about 40% of the electricity consumption of the power system during peak period in summer. Due to the thermal inertia of rooms, indoor temperature will not be greatly affected, when ACs are controlled temporarily to provide regulation capacity. To fully realize the regulation potential, it is of significantly importance to accurately evaluate the regulation capacity of ACs, where the real-time operating status and occupant comfort are two key factors. Therefore, this paper proposes a regulation capacity evaluation method for ACs considering operating status and occupant comfort. The equivalent thermal parameter (ETP) model based on the AC operating characteristics is developed firstly. On this basis, the regulation capacity for the individual AC is evaluated considering operating status and user comfort, and the regulation capacity of aggregated ACs can be obtained by summing. Finally, the effectiveness of the proposed method is proved by cases.
Performance and economy analysis of distributed small-scale pumped storage power station
Authors: Liao Wanting , Zhang Yanchi , Ding Tian , Fang Jun , Ju Pengfei , Xie Da , Zhao Wenbo
Published: February 2022

The installed capacity of clean energy represented by solar and wind power has increased by 77.5 times in the past 20 years. In 2019, it reached 1437GW, accounting for 35% of the total installed power generation capacity [1]. With large quantities of fluctuating renewable and new energy integrated, the power system has insufficient absorption capacity and needs more adjustable power sources. In this paper, the location limitation of centralized large-scale pumped storage power station (PSPS) is broken through and a distributed small-scale PSPS which can be widely constructed in load centers such as the east coast of China is proposed. Furthermore, the distributed small-scale PSPS is compared with large-scale PSPS and other kinds of energy storage technology in terms of installed capacity, discharge time, energy density, power density, life cycle, and per kilowatt hour (kWh) cost. The calculated results show that the energy density of distributed small-scale PSPS is about 10 times higher than that of large-scale PSPS, while the per kWh cost of the two kinds of PSPS is close. In addition, the expected life cycle of distributed small-scale PSPS is higher than that of most energy storage technologies. For example, its life cycle is 4 times longer than that of battery-type storage. In conclusion, the performance and economy of distributed small-scale PSPS are both in the good level, so it has the potential to solve the problem of new energy consumption in China.
Influence of wavelet characteristics on single-phase grounding fault line selection
Authors: Gong Jing
Published: February 2022

It is difficult to select the fault line in distribution network because of the small single-phase grounding fault current. Wavelet transform is especially suitable for fault transient analysis because of its unique time-frequency localization performance. However, the characteristics of different wavelets have a direct impact on the line selection results. Improper selection of wavelets will directly lead to misjudgment. Firstly, the transient characteristics of single-phase grounding fault and the relationship between wavelet transform modulus maxima and singularity are analysed, and the line selection criterion of wavelet modulus maxima is given. Then, the influence of wavelet vanishing moment order, support length, symmetry, and orthogonality on the detection effect of signal singularity is analysed, and four principles for selecting wavelet in fault line selection are proposed. The larger the order of vanishing moment and support length, the more conducive to detection. The influence of vanishing moment order is much greater than that of support length. The 10kV system simulation model is built, five representative wavelets are selected to decompose the zero- sequence current of the fault line in four scales respectively, and the different modulus maxima corresponding to the sudden change point are compared. The experimental results prove the reliability of the wavelet selection principles proposed in this paper.
Effect of acid corrosion on properties of composite insulator core rod
Authors: Shen Hao , Liu Hui , Zhou Chao , Jia Ran , Zhang Yang , Liu Rong , Liu Chuanbin
Published: February 2022

In recent years, there have been a number of composite insulator decay-like fracture faults characterized by resin degradation and irregular fracture morphology, which seriously threaten the safety and stability of power system. At present, the research of composite insulator’s decay-like fracture is still in the initial stage at home and abroad, and there is no clear conclusion on the causes of its fracture, influencing factors and other important scientific and technical issues, and there is no unified understanding of the mechanism of decay-like fracture. In view of the above problems, this paper carries out acid corrosion test on core rod samples to explore the corrosion law of nitric acid on core rod and its influence on properties. The results show that acid corrosion is one of the factors causing the degradation of epoxy resin. With the increase of nitric acid concentration and soaking time, the degradation rate of epoxy resin accelerates, and the core rod sample gradually changes from emerald green to yellowish brown, then to light yellow, and finally to white hair like glass fibre. The effect of the sample under the long-time action of low concentration nitric acid is the same as that under the short-time action of high concentration nitric acid. Nitric acid will continuously erode into the core rod, resulting in the decrease of hardness and performance on the core rod surface.
Research on multi-objective optimal scheduling of virtual power plant based on self-supplied coal-fired power plants
Authors: Liu Wei , Cai Yanchun , Yang Chunxu , Qian Baiyun
Published: February 2022

With the development of renewable energy, improving the absorption capacity of power grid has become a difficult problem. It is very important to establish virtual power plants based on self-supplied coal-fired power plant to coordinate renewable energy consumption, especially in Xinjiang Province, China. This paper studied the optimal scheduling of a virtual power plant including wind turbines, photovoltaic units, and energy storage equipment based on the self-supplied power plant. First, a mathematical model of the power and power generation cost of each unit inside the virtual power plant was established, and the demand response mechanism was introduced. Secondly, a multi-objective optimization model is established by considering the maximization of net income of virtual power plants, the minimization of system coal consumption and the maximization of user interruption load benefits, and the use of analytic hierarchy process to determine the weights of three objective functions, of which user interruption load benefits are used to reflect the enthusiasm of users to interrupt the load. Finally, the particle swarm algorithm is used to solve the model. The optimization results show that when the coal price rises, the net income of the system decreases, and even a loss occurs, however, the change in coal price has little effect on the Interrupted load of user. In addition, multi-objective optimization can improve the enthusiasm of users while ensuring the net income of the system, it proves that the model has a good optimization effect.
Electricity-heat integrated agent modelling for participation in spot electricity market
Authors: Yin Xunhu , Wu Huahua , Su Huangxing , Meng Zhiquan , Yang Xingchao
Published: February 2022

Due to the limitation of market rules, many small capacity power plants cannot directly participate in the spot electricity market, reducing the ability of the market to optimize the allocation of power generation resources. Among these power plants, the electric power output of some combined heat and power (CHP) plants is constrained by their heat output, which should be considered in the dispatch. Therefore, the electricity-heat integrated agents are defined and introduced to aggregate small capacity power plants and participate in the spot electricity market. Firstly, the model of electricity-heat integrated agents is formulated based on the aggregation of the internal generators and CHP units. Then, the framework of the spot electricity market with the participation of electricity-heat integrated agents is constructed. Moreover, the market clearing model is further developed by combining the electricity-heat integrated agent model and the security constrained unit commitment model. Simulation results in the case verify the effectiveness of the proposed model and technique.
Application of least squares fitting algorithm in transformer terminal unit electrical quantities acquisition
Authors: Jiang Chao , Wang Fuliang , Ning Yan
Published: February 2022

In order to accurately estimate the frequency and harmonics of voltage and current signals acquired in transformer terminal unit (TTU), the least squares fitting algorithm is applied to its harmonic analysis. The principle of the algorithm and its flowchart are presented, and the implementation of the algorithm in TTU is primarily discussed. The noisy voltage signals with harmonics and signal frequencies ranging from 49.8 Hz to 50.2 Hz are generated and the real ones are acquired. The harmonic analysis results of the least squares fitting algorithm and the Hanning window and interpolation algorithm reveal that the errors in the signal frequency, direct current (DC) component, amplitude and phase of fundamental and harmonics of the former are only about 1/3 of that of the latter.
Study on aging index of mechanical and electrical properties of high temperature vulcanized silicone rubber
Authors: Zhou Chao , Jia Ran , Qin Jiafeng , Liu Hui , Li Na , Shen Hao
Published: February 2022

Composite insulators are affected by various factors in operation. With the increase of operation time, the shed of silicone rubber composite insulators will become hard and brittle. In this paper, it is found that the hardness of long-term silicone rubber shed meets the standard requirements. The tear strength, tensile strength, elongation at break, resistance to electric tracking and corrosion loss decrease significantly after 5-10 years of operation. The decline of silicone content on the micro surface and the escape of inorganic fillers are the reasons for the deterioration of macro performance. Finally, the evaluation system for aging performance of insulators is preliminarily established, according to the aging degree of insulator, operation and maintenance suggestions are proposed.
Optimal operation of district heat-electric system considering multi-energy flexibility
Authors: Xu Feng , Tao Yuanchao , Qiu Peng , Ding Chao , Lu Yi , Zhao Lebing , Qin Hongpei
Published: February 2022

With increasingly integration of the renewable energy, various uncertainties bring a severe challenge to the operation of the district heat-electric system (DHES). In order to enlarge the accommodation of renewable energy, this paper proposes an optimal operation method of integrated electricity and heat system considering the temporal-coupling feature of multi-energy flexibility. Firstly, the models of multi-energy devices are established to describe the energy conversion. The time delay of heat network is considered and the model of DHES is built as well. Then, considering the uncertainty of load, the time-related upward and downward flexibility constraints are established. The objective function of the optimal economic operation problem is formulated as three parts, including the purchasing price, the operation price, and the curtailment penalty of PV. Finally, a case study based on the IEEE 33-bus power distribution grid and 6-node district heating network is conducted to validate the effectiveness of the method.
Optimal dispatch of a thermal-electric virtual power plant considering heat storage tanks
Authors: Pan Weiwei , Yang Kan , Zhang Yunlei , Wang Dixin , Xu Kangxuan , Li Siying , Sun Shijie
Published: February 2022

Characteristic of thermoelectric coupling of Combined heat and power (CHP) units reduces the flexibility of power generation and heat generation in the “Three-North” region of China. Meanwhile, the uncertainty of renewable energy generation (REG) and demand side management (DSM) pose challenges to the optimal operation of the whole system, leading to difficulty in improving the economic benefits of the whole system. In order to mitigate the above problems, wind generators, solar generators, CHP units, conventional generating units, interruptible loads, battery energy storage systems (BESSs), as well as electric vehicles (EVs) are aggregated into a virtual power plant (VPP) as a community of interest. Particularly, heat storage tanks (HSTs) are introduced into VPP in this paper to realize the decoupling of heat and power of CHP units and enhance the flexibility of the VPP. Firstly, the composition and structure of the VPP are described. Secondly, a day-ahead optimal dispatching model of the VPP considering heat output is established. Finally, the effectiveness of the proposed model is verified by the modified IEEE30 bus system.
Research on heat and power load optimal dispatch based on improved grey wolf optimization algorithm
Authors: Hu Hao , Yang Li , Yu Xiaobing , Xue Yanping , Zhang Zengping , Zhou Gang
Published: February 2022

The heat and power load optimal dispatch (LOD) is a useful method for combined heat and power (CHP) plants to improve energy efficiency and reduce energy consumption. To obtain a better load dispatch effect, this paper proposes the improved grey wolf optimization (IGWO) algorithm and LOD problem constraint processing methods, which constitute three kinds of optimization schemes. The load optimal dispatch research is performed for a typical CHP plant consisting of seven units and different optimization schemes are discussed. The results show that the power generation cost obtained from the proposed optimization scheme is lower than the data obtained by a single algorithm in the literature. The results also indicate that the adopted constraint processing method can well solve the characteristics of multiple constraints of the LOD problem. Meanwhile, the comparison results of different schemes show that the IGWO algorithm has more obvious advantages in the performance of better convergence and robustness, meaning it is more suitable for solving the LOD problems. In short, the improved algorithm can accurately solve the load matching problem between power plants and power and heat grids, providing better solutions.
Low-frequency oscillation suppression strategy considering dynamic power characteristics of energy storage system
Authors: Wang Yunling , Liu Fang , Du Xinwei , Li Bo , Liu Yang , Jiang Libo
Published: February 2022

Aiming at the problem of low-frequency oscillation in the weak power grid, a low-frequency oscillation suppression strategy considering the dynamic power characteristics of the energy storage system (ESS) is proposed in this paper. Firstly, the principle of low-frequency oscillation in the power system is analyzed by using a single machine infinite bus system. Secondly, considering the dynamic characteristics of the ESS output active power, a controller for the ESS to suppress low-frequency oscillation is designed, which can provide positive damping for frequency oscillation of the power grid. Finally, the simulation analysis and experimental results of an actual weak grid are carried out to verify the effectiveness and feasibility of the proposed method. The results show that the suppression effect of the low-frequency oscillations is related to the ESS location in the weak power grid.
Investigation of key factors of Blackman-Harris window and interpolation algorithm in TTU frequency estimation module
Authors: Ge Yonggao , Wang Ning , Zhu Zujun
Published: February 2022

In order to provide a reference for the selection of related parameters when the Blackman-Harris window and interpolation algorithm is applied to the frequency estimation for voltage and current signals in transformer terminal unit (TTU), the principle of the algorithm is introduced, the implementation is preliminarily discussed, and the influence of signal parameters and measurement parameters on the frequency error is investigated based on the numerically generated voltage signals. The results reveal that the error is proportional to the frequency deviation of the signal. The frequency error decreases exponentially with signal-to-noise ratio (SNR) and sampling duration. Total harmonic distortion, sampling frequency and analog-to-digital converter (ADC) quantization bit have almost no impact on frequency error.
Research on the scheduling of unit operation mode for combined heat and power plants considering new energy consumption in heating season
Authors: Lin Chengkun , Song Jiwei , Wang Congyu
Published: February 2022

China aims to peak carbon dioxide emissions before 2030 and achieve carbon neutrality before 2060. The traditional coal power plants need to reduce theirs power load as much as possible to reduce CO2 emissions and improve the consumption capacity of intermittent renewable energy. Nevertheless, in part of northern China, areas with a high proportion of combined heat and power (CHP) units in coal power, CHP units need to provide heat load during heating season so that the flexibility of power load adjustment for CHP units is restricted. The plant minimum operation mode model is proposed to excavate the plant-level lower boundary of power load. By analysing the heat-power coupling mechanism of each unit, under different unit commitments, the plant-level lower boundary of power load can be calculated through dispatch heat load reasonably. Then the scheduling scheme of optimal unit commitment for plant is obtained. The comparison of results with the actual operation of a case CHP plant shows that the consumption capacity of renewable energy can be increased by 1.92 billion kWh and the CO2 emissions of the reference plant could be reduced by 52.5% under the scheduling scheme of optimal unit commitment during the heating season. The reduction of CO2 emissions for the scheduling scheme of optimal unit commitment will remain more carbon allowance which can bring revenue from carbon trade market. The scheduling of unit operation mode provides a way of operation under the current policy and environmental background, how to depress the power load of CHP plants and reduce CO2 emissions in heating season.
A fast frequency estimation algorithm and its application in transformer terminal unit
Authors: Li Cheng , Li Jun , Chen Zhiming
Published: February 2022

To accurately obtain the frequency of voltage and current signals and form the basis for the analysis of power quality in the Transformer Terminal Unit (TTU), a Hanning window and interpolation algorithm is proposed to estimate the signal frequency. The principle of the algorithm is introduced, and the computer program is written. At the same time, the voltage signals with different frequencies are numerically generated and the real voltage is measured, and the signal frequency is estimated by using the algorithm. The results reveal that the proposed method can accurately estimate the signal frequency for TTU, and the maximum error of frequency estimation is only 2 mHz when the signal frequency varies in the range of 49.8-50.2 Hz. However, the maximum error estimated by the FFT algorithm is up to 0.2 Hz. The computation time of the Hanning window and interpolation algorithm is only 1.29 times that of the Fast Fourier Transform algorithm. The work lays the foundation for accurate and rapid estimation of voltage and current signal frequency in TTU.
Modeling of large capacity condenser based on electromagnetic transient simulation and its impacts on East China Power Grid
Authors: Xie Hongping , Huang Tao , Zhao Weiguo , Sun Ke , Lin Dongyang , Huang Qinxin , Yang Mengmeng
Published: February 2022

With the development of long-distance transmission of higher voltage levels, the loss of reactive power on transmission lines is increasing. The dependence on the external electricity is also rising, so that the voltage stability problems of the receiving system have become increasingly prominent. Therefore, using dynamic reactive compensation technology can improve the operating characteristics of the power grid and improve the safety and stability of the system. Based on the electromagnetic transient data of East China Power Grid in 2025, based on the parameters of the new large-capacity synchronous condenser, the electromagnetic transient model of the synchronous condenser is established and simulated. The simulation results show that after the installation of synchronous condenser, the minimum voltage of ZP bus is improved to different extents, the voltage recovery time is reduced to different extents. It also plays a certain role in reducing the number of commutation failures. Therefore, the installation of the synchronous condenser can provide effective dynamic reactive support for the local power grid with high proportion of DC power, which can reduce the probability of DC commutation failure in the AC grid fault.
Experiment research of Al particle’s ignition and combustion characteristics of NEPE propellant
Authors: Xia Wenjie , Zhuang Yuqian , Cai Wenxiang , Xue Donglin , Cao Yanbang , Song Xiaodong
Published: February 2022

Based on optical photography analysis method, agglomeration process of Al particles at aluminized NEPE propellant’s surface, dynamic combustion process after leaving burning surface and the collision under different pressure of N2, were photographed by highspeed camera. MATLAB was used to deal with the images to analyze the size of agglomerated particles. Experiment research results showed that higher pressure was helpful for improving ignition performance and increasing combustion efficiency of the aluminized NEPE propellant. For the agglomeration products, dimension was reduced, size distribution became more uniform, and amount of the mass increased with higher pressure environment.
Research and system design of energy dynamic balance and optimal scheduling of iron and steel enterprises
Authors: Meng Hua , Huang Yi , Zheng Chunni , Zhou Ya , Chen Yanru
Published: February 2022

The steel industry is an important part of the secondary industry, and it has a strong role in promoting economic development. However, the steel industry is a high-energy-consuming industry, which has large energy consumption and waste of resources. Therefore, it is very important to do a good job of energy conservation and emission reduction in iron and steel enterprises. Therefore, this paper studies the dynamic energy balance and optimization model of iron and steel enterprises firstly, and further designs and operates the system based on this. It is show that the model has good practicability, which can balance the pipe network and reduce emission.
Geometry contributions to natural convection heat transfer enhancement by the chimney effect
Authors: Njoroge John , Gao Puzhen
Published: February 2022

Natural convection heat transfer enhancement continues to be an evolving problem in the design of passive safety systems in nuclear engineering. Increasing heat rejection rates guarantees safety and higher heat duty. This study numerically investigated the influence of the geometry of an adiabatic extension appended downstream of a vertical heated cylinder. Four geometries comprising straight, diffuse, hyperboloid, and compound adiabatic extensions were studied. Nusselt number ratios, temperature distribution ratios, and mass flow rates were presented. Results showed that the compound extension geometry exuded high heat transfer enhancement capabilities by the chimney effect, and reduced wall temperature by up to 16% for the range of parameters studied. These findings are presented as a contribution to the design improvements of air-cooled passive systems, especially in advanced nuclear reactors.
Pyrolysis characteristics, kinetics and thermodynamics of the plywood material in high-speed trains
Authors: Wei Lingling , Li Li , Qiu Tingting , Li Changhai , Lu Shouxiang
Published: February 2022

The pyrolysis characteristics, kinetics and thermodynamics of a typical plywood material, namely the Huangjinguomu plywood in high-speed trains in nitrogen were studied in the present study. It was indicated that three peaks occurred in the reaction rate curves. The pyrolysis process can be divided into three stages, namely stage 1: 0<a<0.1, stage 2: 0.1<a<0.7 and stage 3: 0.7<a<1. With the increase in the heating rate, the first and third peak reaction rate decreased, while the second peak reaction rate increased. The average reaction rate in stage 1 and throughout the entire pyrolysis process decreased. The average reaction rate in stage 2 increased. The average reaction rate in stage 3 remained almost constant. The second stage may be nominally considered to be a one-step reaction. The pyrolysis of the Huangjinguomu plywood was a non-spontaneous and endothermic process. The AG value maintained almost constant with the progressing of the thermal decomposition. The average values of AH, AG and AS were 191.55 kJ/mol, 139.29 kJ/mol and 92.93 J/(molK), respectively.
Current situation and trend analysis of electrification level of terminal energy consumption
Authors: Tang Wei , Zhang Yu
Published: February 2022

Under the background of carbon neutral, improving the level of terminal electrification can promote the use of clean energy and improve the efficiency of energy use, which is an important means to accelerate the low-carbon transformation of energy, promote the sustainable development of economy and society, and achieve the goal of “carbon peak, carbon neutral”. This paper analyzes the current situation of China’s terminal electrification level from different dimensions, analyzes the development trend of these factors, and forecasts the future terminal electrification level through qualitative analysis of influencing factors and data calculation.
Characterization of combustion behavior of commercial flame-retardant plywoods in fire propagation apparatus
Authors: Qiu Tingting , Zhang Xueling , Lu Shouxiang , Zhang Guoan , Hou Lijun
Published: February 2022

This paper deals with the combustion behavior and thermal decomposition of two typical kinds of plywoods used in composite floor. The experimental study was performed in fire propagation apparatus and combustion parameters including ignition time, heat release rate, mass loss rate and effective heat of combustion were analysed. The results show that the risk of ignition and heat release of alder is higher than that of Huang Jin Guo Mu under most heat fluxes. Three thermal decomposition stages are proposed according to the characteristics of mass loss rate and temperature profiles. The present work provides input parameters for numerical modeling and gives guidance for fire risk assessment of rail transit.
Effects of upstream shear flow on performance and flow characteristics of the drag-type hydrokinetic rotor
Authors: Cao Qian , Kang Can , Peng Shan , Zhao Bo , Zhang Wenbin
Published: February 2022

Effects of the incident shear flow on operational performance of a drag-type hydrokinetic rotor were investigated numerically. A flow visualization experiment was conducted to validate the numerical method. Energy conversion ability of the rotor under different incident shear flow conditions were analysed. The effects of the tip speed ratio were also taken into consideration. The results show that under the incident shear flow conditions, the upstream flow inclines downward and the velocity magnitudes at the upper and lower side of the rotor are significantly different, which affects the operation of the rotor. As the shear coefficient increases, the azimuthal angle range corresponding to the negative torque coefficient reduces and the fluctuation of the torque coefficient with the azimuthal angle appears delay phenomenon. The tip speed ratio has a great effect on the flow patterns around the rotor. The shape and position of the flow structures downstream of the rotor vary obviously with the tip speed ratio. The results are anticipated to provide sound support on the design and optimization of the drag-type hydrokinetic rotor in actual condition.
Exploring the promotion method and pathway of energy big data service business
Authors: Yan Qibo , Ji Huiqiang , Chen Jingcheng , Wang Xudong , Gao Yi , Zhang Xiaochun , Wang Yongli , Zeng Ming
Published: February 2022

In the wave of China’s new energy revolution and digital revolution, advanced information technologies such as big data, cloud computing, Internet of Things, mobile Internet, and artificial intelligence have been deeply integrated with the energy industry, and energy big data has emerged as the times require. Energy big data promotes new models and new formats in the energy sector. The vigorous rise of energy big data has injected new impetus into the energy transition. With the explosive growth of energy data and the continuous improvement of data processing capabilities, energy big data has become a new element of social production, and different social entities have corresponding business needs. Therefore, this article is based on the three basic business promotion theories of growth cycle, growth framework and growth strategy with growth hacking theory as the core, and considers the different characteristics of government, enterprises and residents in terms of customer acquisition cost and life value. Finally, this article puts forward energy big data service business promotion models for governments, enterprises and residents which are based on the five stages of the user life cycle.
Design of utilization cold energy and economic analysis on LNG carrier
Authors: Zhang Xiaorong , Yue Rongqin , Li Boyang
Published: February 2022

Based on the principle of energy cascade utilization, this research uses 147000m3 LNG carrier as the research object. According to the principle of energy cascade utilization, LNG cold energy is applied to Rankine cycle power generation, ship desalination, ship low-temperature cold storage, ship high-temperature cold storage, ship air conditioning and nitrogen production, etc. Design a set of LNG cold energy comprehensive utilization system. Using Aspen HYSYS software for simulation, after analysis and calculation, the feasibility of the system design scheme was demonstrated. According to the route of the parent ship and the operating conditions of the cold energy utilization system, calculate the electricity and economic benefits saved by the LNG cold energy utilization system in each month. Through calculation, it can be known that 1.886×106 kW·h of electricity can be saved in one year, resulting in a benefit of more than 4 million yuan. The results show that the cold energy utilization system can bring good economic benefits and is worthy of promotion and application on ships.
Global LNG market: supply-demand and economic analysis
Authors: Zou Qian , Yi Chenggao , Wang Keming , Yin Xiuling , Zhang Yongwei
Published: February 2022

The transition to clean and low-carbon energy is an irresistible trend globally that drives the scale of trade in the global LNG market to grow continuously. The paper reviews the global LNG trade in 2020 and forecasts the future LNG supply and demand. On this basis, the costs in segments of a LNG project are analysed from the perspective of the LNG industry chain. The feasibility of export from LNG projects and the preferred target markets are determined by calculating the economic index of projects. It is concluded that the possibility of future rebound in oil prices and the demand growth in the incremental market in emerging Asian countries are most likely to determine the capacity scales of new LNG projects around the world and contribute to a dynamic balance in the LNG market in the medium- and longterm. The costs in different segments of the LNG industry chain vary greatly with the availability of resources and markets. The economics of LNG export depend on the demand for LNG imports in end markets, the cost plus in different segments of the industrial chain, and the affordability of end consumers. Through the cost and economic analysis on typical LNG Projects, Qatar is found still the most economical and highly profitable country in the global LNG export market nowadays. Unsatisfactory economic performance is a common reason for delayed investments in many large LNG projects in Australia and other countries.
Impact of re-electrification on energy and environment in residential sector: towards 2030 carbon peak for Yunnan
Authors: Wang Peng , Cheng Beibei , Li Qiushuo , Zhu Xianwen , Li Kangyan , Xie Yanjun , Shu Jie
Published: February 2022

The energy consumption of the residential sector accounts for about 20% of the total energy consumption of the whole society, and the energy consumption in the residential sector increases year by year, becoming the main growth source of carbon emissions. In this study, scenario analysis method is used to analyze the energy consumption, carbon dioxide emissions and pollutant emissions of residential sector in Yunnan Province from 2019 to 2035. The results show that in the scenario of deep re-electrification, the carbon emission of residential sector can reach the peak in 2029. At the same time, it can bring the collaborative emission 65% reduction of NOx and SO2.
An impact of solar PV specifications on module peak power and number of modules: A case study of a five-bedroom residential duplex
Authors: Mayokun Abolarin Sogo , Babale Shitta Manasseh , Aghogho Emmanuel Metuaghan , Precious Nwosu Blessing , Chucks Aninyem Michael , Lagrange Louis
Published: February 2022

This paper presents a case study using an analysis of solar PV modules peak power to determine the optimum number of PV modules required to supply energy to certain typical household appliances. The approach could be used for selection of solar PV modules that produce a satisfactory energy yield to meet pre-determined energy needs. In the analysis, the maximum daily energy consumption values corresponding to the lighting and air-conditioning loads were determined through an energy audit conducted on a residential building unit in Lagos, Nigeria. The maximum daily energy consumption values of these appliances were programmed into a NCEEC_e-EASZ VBA simulation tool to determine the solar PV array peak power and the number of modules required to produce the required solar energy yield. The methodology was validated with literature and HOMER Pro software. Eighteen different commercially available modules spanning a range of specifications including unit peak power varying from 280 to 400 W were investigated in order to select the most suitable panels for the provided conditions. The minimum required number of PV modules required to make up an array to produce the required yield was determined. The result indicates that when the unit peak power of the modules increases, the number of modules required to meet the daily energy demand reduces. The rating of solar PV modules between 280 - 400 W constituted a significant role in the process of analysing peak power as well as the quantity of solar PV modules required.
A study on resource reallocation in regional energy networks based on the adjustment of supply and demand nodes
Authors: Zhou Xichao , Cong Lin , Li Na , Zhu Haifeng
Published: February 2022

In this paper, we propose and analyse a regional energy network resource allocation scheme and optimization model for regions where the number of energy supply nodes grows seasonally, including the optimal division of the energy supply range of each energy supply node based on distance, the optimal path planning scheme of the energy pipeline network connecting energy supply and consumption nodes, and the optimal allocation/reallocation model of regional energy network resources with the objective of optimal operational economy. The proposed scheme for the optimal redistribution of regional energy network resources is used to analyse and study the case area, and a scheme for the division of energy supply nodes in the case area, a scheme for the construction path of energy pipeline network and a planning strategy for the optimal redistribution of energy network resources are developed to verify the feasibility of the method in this paper.
Operation-related features of diesel fuel injection systems at pressures up to 400 MPa
Authors: Zhao Jianhui , Grekhov Leonid , Denisov Alexander , Onishchenko Dmitry
Published: February 2022

The interest in the high pressure injection in diesel engines continues to grow. Optimal injection pressure is a function of the engine parameters and its application and is open to question. The study investigates the injection features of diesel fuel at pressures above 300-400 MPa. The injection pressure level, at which the fuel flow through the nozzle ceases to grow, was experimentally determined, and an improved simulation method for the heavy fuel injection modelling was proposed.
Research on optimization of annealing process based on N-type TOPCon solar cell
Authors: Gu Na , Ji Xiaofeng
Published: February 2022

In recent years, developing new structure and technology has always been an important link in the production and manufacture on photovoltaic cells. Among all high-efficiency crystalline silicon solar cells, the tunnel oxide passivated contact (TOPCon) solar cell has attracted much attention due to its excellent passivation and compatibility with the traditional crystalline silicon solar cells. This article first introduces the basic structure and process route of the tunneling oxide passivation contact (TOPCon) solar cell. Then the annealing process was studied. Experiments on the effects of different annealing temperatures and times on the doping characteristics were carried out, and the experimental results were analyzed. The experimental results show that the annealing temperature and time have a very important effect on the annealing effect of ion implanted silicon. Finally, the light injection annealing process is researched and experimented. Experimental results show that the efficiency of the light injection annealing method is significantly improved, which is mainly manifested in the improvement of Voc (open circuit voltage) and FF (fill factor).
Numerical simulation research on the fire in cable cabin of utility tunnel with different longitudinal fire source locations
Authors: Geng Dewang , Cao Bei , Zhou Xiaodong , Liu Hong , Lu Ziping , Yang Lizhong
Published: February 2022

A full-scale model was established by the Fire Dynamics Simulator (FDS) to study the fire characteristics in the cable cabin of utility tunnel with different longitudinal fire source locations. Five fire sources at different locations were placed in a 200-meter-long fire compartment. Several important parameters were obtained and analyzed, including temperature distribution, smoke concentration, and fire self-extinguishing. The results present that the fire source located at 1/2 of the longitudinal direction has the largest range of high-temperature smoke, which leads to the largest damage range of the concrete structure. The reverse filling of the smoke in the utility tunnel leads to the longitudinal CO peak concentration first decreasing and then increasing from the fire source to the end. When the fire source is located at 1/8 of the longitudinal direction, the fire self-extinguishing time is the longest. These encouraging results could provide significant references for the fire protection design and fire control of the utility tunnel.