bluuebunny/crossref_metadata_2025 huggingface dataset:
Feasibility analysis on the coupling power system of municipal solid waste incinerator and coal-fired unit
Authors: Miao Shanshan , Wang Dehua , Yin Yaning , Han Shengli , Wang Ting , Li Chong , Huang Ying , Guo Xin , Wang Weilai , Yu Qiang , Zhu Yingwei
Published: March 2021

In this paper, the coupling capacity matching is related to chlorine content in MSW incinerator, denitrification and desulfurization efficiency of coal-fired boiler. Based on an 850 t/d municipal solid waste (MSW) incinerator and a 1000MW ultra-supercritical coal-fired unit, the effect of the dual-chain coupling of steam and flue gas on the coal-fired unit is studied, including corrosion of heating surface in furnace, dioxin emissions, pollutants emission, and fly ash comprehensive utilization. Through the influence research to the coal-fired boiler, it can be seen that influence on the heating surface is small at high temperature. The flue gas environment of coal-fired boiler can also inhibit the synthesis of dioxin and the flue gas of waste incinerator meet to the ultra-low emission standard of pollutants of coal-fired units and the heavy metals content of fly ash of coal-fired boiler is not hazardous waste. After the coupling, the generation efficiency of MSW incinerator can rise up from 20% to 31.6% and the MSW incinerators operate investment reduced by 40% with significant economic benefits. The coupling mode can be generalized of waste incinerator and coal-fired boiler that obtain feasibility for engineering application.
Numerical study on the different prevention methods for fire and smoke in utility tunnel fire
Authors: Cao Biteng , Yang Lizhong , Wang Hengdong , Xu Qiong , Li Bin
Published: March 2021

Series numerical simulations of fire in utility tunnel have been performed by Fire Dynamics Simulator (FDS) in this paper. The main purpose is to investigate the smoke prevention effect of fireproof door, water mist curtain, air curtain and ceiling screen. The pressure of water mist, airflow velocity of air curtain and the height of ceiling screen were considered. The results show that once a fire occurs in the pipe corridor, fireproof door has a good effect of smoke preventing and cooling. The water mist curtain, air curtain and smoke ceiling screen systems all have a blocking effect on fire and smoke, and the best fire smoke prevention parameters of water mist curtain and air curtain applied in underground comprehensive pipe gallery are 10 MPa and 10 m/s respectively. Therefore, the fireproof door, water mist curtain and air curtain systems can be set in pipe gallery to prevent fire and smoke, so as to improve evacuation safety and emergency rescue efficiency.
Calculation of environmental capacity and pollutant discharge in Changxing county based on sustainable development
Authors: Wu Jianfeng , Wang Junmin , Fu Lei , You Aiju
Published: March 2021

Due to the improvement of the understanding of the natural environment and social service function of rivers, many countries in the world have started the research and practice of water environment protection. Lots of Chinese cities also paid most of their attentions to the water environment especially in the river network area. Systematic calculation and analysis of the water environment status becomes famous in most of the Chinese cities, which not only shows the current status of water environment but also indicates the methods to reduce the domestic pollution. In this study, Changxing county is selected as a typical Chinese city, COD (Chemical Oxygen Demand) and TN (Total Nitrogen) are considered as two typical pollutants, both water environmental capacity and current pollution are calculated. From the comparison between the present pollution load and the discharge limit into the river, it can be seen that TN is the key influencing factor of the water environment carrying capacity in Changxing County, and its overload ratio is up to 5.0. A series of measures to reduce the pollution load into the river are put forward in order to provide an auxiliary decision-making basis for further protecting “clear water and green mountains”.
The wind-PV-hydro-thermal multi-source cleaning dispatch with the influence of super-power thermal storage boiler
Authors: Ge Weichun , Liu Debao , He Huan , Wang Shunjiang , Jiao Zhen , Zhao Xuanyuan
Published: March 2021

Aiming at the problem of serious waste of clean energy caused by the randomness and volatility of clean energy output during the winter heating period in Northeast China, this paper proposes a dispatching scheme of super-large power regenerative electric boiler, which fully combines the different physical characteristics and respective advantages of power systems and thermal systems. To maximize the economic and environmental benefits of wind-PV-hydro-thermal and other multi-energy joint dispatching, an optimal dispatch model is constructed with the lowest overall power generation cost as the dispatch target considering the power generation operating cost of the thermal power unit, the cost of abandoned light, the cost of abandoned water, the cost of abandoned wind, and the heating income of super-large power storage boilers combined together. The improved PSO algorithm based on multi-agent is used to solve the model. The results of the calculation example show that, after considering the absorption capacity of the super-large power regenerative electric boiler, the operating cost of the system is reduced by about 10%, and under the premise of ensuring the safe and stable operation of the system, the utilization rate of clean energy utilization and the system operation economy is improved.
Effect of goods stacking mode on temperature field of cold storage
Authors: Tang Yanlin , Hu Zuoxin , Tang Tianyu , Gao Xin
Published: March 2021

The distribution of temperature field in cold storage is affected by different stacking patterns of goods. To explore the influence of goods stacking way on cold storage temperature field, computational fluid dynamics (CFD) was used to simulate the influence on temperature flied of cold storage by different types of stack arrangement methods under a new air outlet design way in this article. The three types of stack arrangement included stacking along the X axis, along Z axis, and along Z axis with 10cm thick dunnage board. The simulation result shows that the temperature distribution inside the cold storage is the most uniform when goods are stacked along the Z-axis and filled with 10cm thick dunnage board. The simulation on this type of arrangement well agreed with measured results. This work would give out research reveal the features of the temperature distribution in cold storage with vent series. This would be helpful on design of the cold storage and the stack arrangement.
Evaluation of carbon dioxide storage in the deep saline layer of the Ordovician Majiagou Formation in the Ordos Basin
Authors: Lu Ping , Liu Weigang , Gao Chunyun , Zhao Junhui , Bai Yong
Published: March 2021

Geologic CO2 storage (GCS) is one of the preferred solutions to reduce greenhouse gas emissions. Comparing with other geological reservoirs, the deep saline aquifers have huge storage potential and currently the most promising one. Since technical and economical viability of geologic CO2 storage depends highly on the CO2 storage capacity, this paper mainly uses the storage mechanism method to estimate the CO2 storage capacity of the Ordovician Majiagou Formation in order to give data support for GCS project in the Ordos Basin. The results show that the total effective CO2 storage capacity of the deep brine layer of the Ordovician Majiagou Formation in the Ordos Basin is 15.98-109.22Gt. The Majiagou Formation has sufficient storage capacity to accommodate decades of CO2 emissions generated by multiple coal-fired power plants in the Ordos Basin. For CO2 geological storage, the structural trapping mechanism contributes the largest amount of CO2 storage, and the amount of CO2 storage contributed by the two mechanisms of bound gas trapping and solubility trapping is almost negligible. The above results provide methods and references for CO2 estimation of GCS project in this region, and provide data support for the site selection and injection of CO2 sequestration in deep salt layers of the Ordos Basin.
PWM rectifier impedance modelling and analysis
Authors: Bie Yiyuan , Li Yang , He Guoqing , Zhang Xing
Published: March 2021

PWM rectifiers are widely used in the field of new energy power generation. The study of small signal impedance modeling of PWM rectifier is helpful to analyze the stability of new energy grid connected impedance. In this paper, the small-signal impedance model of the PWM rectifier is first established, and then the impedance model of the PWM rectifier is scanned through MATLAB using the impedance sweep method, and compared with the analytical expressions in this paper, the accuracy of the impedance model of PWM rectifier established in this paper is verified.
Research on bidding mechanism and strategy of hydropower unit based on coupling resources
Authors: Ding Wenjiao , Lu Zhanhui , Wang Bangcan , He Peishan , Liu Yu , Liu Runze , Jing Zhaoxia
Published: March 2021

The construction of the electric power spot market in China is at an initial stage, and there is a contradiction between the bidding mode of single-unit bidding and the physical operating characteristics of cascade generating units. When all generators in the market make price declarations and settlements independently, the dispatching and clearing results may violate the operating performance of the actual units, bring difficulties to the unit joint bidding, and at the same time cause serious deviations in scheduling and waste of actual resources. Therefore, for the power generation resources coupled with resources such as cascade hydropower units, this paper proposes a bidding mechanism based on aggregation nodes. First, the bidding mechanism and bidding strategy of the aggregation node is introduced in detail, and then the spot market-clearing model of the aggregation node bidding is established. Finally, the IEEE5 simulation shows that the bidding mechanism based on the aggregation node can make the market-clearing result reflect the unit’s willingness to trade, effectively allocate cascade hydropower generation resources, and improve market transaction efficiency.
Control method of power grid topology structure based on reinforcement learning
Authors: Yang Yanhong , Pei Wei , Deng Wei , Xiao Hao , Sun Hongjian
Published: March 2021

With the rapid development of renewable energy and power electronics technology, uncertainty, complexity and data accumulation in power system continue to increase. Traditional methods often encounter bottlenecks in solving operational optimization decision-making and control problems. The development of artificial intelligence technology provides new methods and means for solving the problem of intelligent control of power grid topology. The deep reinforcement learning (DRL) method is used to learn from the historical experience data of power grid topology control that can improve the control and decision-making and methods of system operating performance, and solve the huge variables in traditional models. Through the method in this paper, the DRL method can effectively improve the real-time optimization and control ability of the grid topology.
Research on optimizing controller parameters based on transient energy function to improve the stability of weak transmission system
Authors: Xie Huan , Lu Jiali , Zhao Feng , Zhao Tianqi , Xu Peng , Xia Xue
Published: March 2021

This paper takes the Ximeng-Taizhou UHVDC transmission weak transmission end AC system as the background, and proposes to optimize the low-voltage current limiting control link (VDCOL )to improve the stability of the system. First of all, this paper analyzes the working principle and limitations of traditional VDCOL, and proposes that the short-circuit ratio of the sending end and the voltage of the commutation bus at the receiving end are used as the variables of the VDCOL cut-off voltage to achieve the effect of optimizing VDCOL. Make the cut-off voltage a value that changes with the change of the inverter side commutation bus voltage, which can take into account the recovery speed of the AC and DC systems. The process of constructing the transient energy function considering the dynamic characteristics of the DC system is analyzed in detail, and the real-time digital simulation software RTDS is used to build a single-machine infinite-DC simulation example. Based on time-domain simulation software and transient energy function margin method, the optimization of the low-voltage current-limiting control link in the DC control system is verified to improve the stability of the sending-end AC system.
An optimization and evaluation method construction of zero-energy residential building renovation
Authors: Wu Weidong , Meng Qi , Lv Yajun , Li Xinyang , Hou Huanyu , Gao Ying , Cao Wen
Published: March 2021

Zero-energy renovation is carried out on the envelope structures and renewable energy systems of the reference buildings, and control function was constructed with the energy-saving quantities in the total life cycle of the renovated and pre-renovation buildings, which was optimized and solved using the NSGAII (Non-dominated Sorting Genetic Algorithm II) to obtain the optimal renovation scheme. The entropy weight evaluation is employed to evaluate the optimal scheme. The reference buildings are subjected to energy-saving renovation according to the optimal method, and the relationship between energy supply and energy consumption is analyzed for each reference building in each month. This study offers a method for the optimization and evaluation of zero-energy consumption in residential buildings, which provides guidance for the zero-energy residential building renovation.
Research on AC/DC hybrid system real-time simulation progress improvement
Authors: Li Yang , He Guoqing , Zhang Xing
Published: March 2021

In order to improve the accuracy of real-time simulation of power electronic transformers, all models are based on FPGA modeling, and a mathematical model of power electronic transformers suitable for FPGA operations has been established. Aiming at the simulation error caused by multi-rate simulation, this paper analyzes the source of simulation error, proposes a step wave average communication algorithm, which improves the oscillation and jitter of simulation results. The simulation platform is connected to the real controller of power electronics and the real controller of new energy generation unit. The real-time simulation verification is carried out for the dynamic characteristics, control performance and stability of AC / DC system. The simulation results verify the reliability and practicability of the simulation platform.
Design and development of CEWES software for complex environment wind engineering simulation
Authors: Zhao Fan , Wu Shuang , Qi Chen , Bai Hanli , Wang Xianzhuo
Published: March 2021

The design and development of the complex environment wind engineering simulation software CEWES was carried out, relying on the National Numerical Wind Tunnel Project (NNW). First, based on the characteristics of the physical problem that the software aims to solve, the requirements for the development of complex environment wind engineering simulation software are proposed, and three main modules of the software will be developed: structured grid flow field solver, unstructured grid flow field solvers modeling module of complex terrain and surface. Subsequently, the appropriate mathematical and physical model and numerical solution algorithm are selected for the flow field solver. The CEWES software uses the finite volume method for discretization with second-order accuracy, solves the RANS equations based on the SIMPLE algorithm, uses the k-ε turbulence model to solve the turbulence, and supports large-scale parallelism calculation. Third, the software design was carried out in accordance with the requirements of the CFD solution process and the modular program, focusing on the program architecture, data structure and subroutine interface design, and coding implementation based on the detailed design. Finally, the CEWES software was tested with typical examples. The test results of the calculation examples show that the software calculation results have good accuracy and large-scale parallel computing capabilities, and are suitable for wind engineering simulations in complex terrain environments.
Scenario analysis of wind power output based on improved k-means algorithm
Authors: Wang Weiyuan , Dou Fei , Yu Xuan , Liu Gaowei
Published: March 2021

To ensure the safety and reliability of grid operation, an accurate description of wind power output is crucial. In this paper, the Grey Wolf Optimization algorithm (GWO) optimized by the Cuckoo Search algorithm (CS) is proposed to improve the traditional k-means clustering algorithm and the improved k-means algorithm is applied to the scenario analysis of wind power output. The simulation results show that the error between the typical scene and the initial scene is only 4.56% when reduced by the improved k-means algorithm, so the typical scene not only maintains the temporal sequence of the initial scene, but also fits the output fluctuation and randomness of the initial scene well.
A review of bearing fault diagnosis for wind turbines
Authors: Liu Bing , Liu Baixin , Dai Qingbin , Liu Huaping
Published: March 2021

Bearings are the core components of the wind turbine’s mechanical transmission system, but the bearings of wind turbines are prone to wear and failure during vibration, and it is often difficult to determine the fault-bearing status and fault location. Therefore, the monitoring and fault diagnosis of wind turbine bearing status are very necessary. This paper introduces the types of bearings of wind turbines and common faults of bearings, analyzes from the aspects of bearing vibration data and supervisory control and data acquisition (SCADA) systems, summarizes the existing fault diagnosis methods and systems of wind turbine bearings, and points out the basics of these methods thought. Finally, the research focus of future bearing fault diagnosis is elaborated.
NDM-based H-infinity robust control of parallel-connected grid-connected converters for V2G
Authors: Zhou Shilian , Li Longfang , Ben Shujun , Long Bo , Chen Yong
Published: March 2021

Because of the unignoring line-impedance, distorted grid voltage, high penetration and the increased parallel-connected grid-connected converters (GCC) in vehicle-to-grid (V2G) system, the stability of the grid with electric vehicle (EV) faces new challenges. To deal with the stability problem, this paper proposes a numerator-denominator-model (NDM) based H-infinity controller combined with an adaptive capacitive-current-feedback active damping method with explicitly robust stability in terms of variations on filter parameters, time-delay and grid-impedance. Simulation results are investigated in two parallel-connected GCC in EV and show the validity of the proposed method.
Research on control strategy of maximum power tracking variable step size perturbation & observation method for photovoltaic power generation system
Authors: Gao Zhen , Kai Fei , Xi Ziqiang
Published: March 2021

There are three defects of traditional perturbation and observation method in the maximum power tracking control process of photovoltaic power generation systems, which are oscillation, misjudgment and poor tracking accuracy. Thus, a variable step perturbation and observation method based on power prediction is proposed for three-level DC/DC converters in this paper, which effectively solved oscillation, misjudgment, tracking accuracy problems, improving the tracking speed and precision of the algorithm, and the verification results of the maximum power tracking algorithm based on the three-level DC/DC converter structure has also been indicated.
Optimization of back pressure control of direct air-cooling unit based on GPC
Authors: Bai Jianyun , Shao Ru , Ren Qi
Published: March 2021

In view of the fact that the actual back pressure is difficult to track the set value quickly and stably, this paper applies the predictive control algorithm (GPC) which can respond quickly, has good robustness and is easy to realize in the industrial production site to optimize the back pressure control. The control performance of the back pressure control system with PID, fuzzy PID and GPC is compared and analyzed through the simulation test. The simulation results show that the GPC algorithm has better dynamic performance than PID and fuzzy PID control in the case of set point disturbance and internal disturbance, and has stronger robustness in the face of model mismatch. To sum up, GPC algorithm is more suitable for the back pressure control system under complex working conditions, and the optimization control method has a certain guiding significance for the actual production site back pressure control strategy improvement.
Simulation analysis of the influence of compressor speed on a solar-assisted heat pump hot water system
Authors: Li Zuqiang , Huang Xinghua
Published: March 2021

Inverter compressors have great potential in improving the overall performance of the solar-assisted heat pump (SAHP) system. However, in the actual process, due to the uncontrollability of environmental factors, the relationship between compressor speed, environmental factors and system performance is complicated, so that it is difficult to obtain intuitive data through operating experiments. Therefore, based on the SAHP system, a quasi-steady-state mathematical model is established using the Engineering Equation Solver (EES). And use this model to study the relationship between compressor speed and heat pump system performance. The simulation results show that when the ambient temperature is 20°C, if the heat collection efficiency is not lower than 0.45, when the solar radiation intensity is 400, 600 and 800 W/m2, the best compressor speed values are 1600, 1800 and 2400 r / min, the corresponding system coefficient of performance (COP) will reach the maximum value at this time, which are 7.7, 8.6 and 8.4 respectively. In addition, compared with higher solar radiation, at lower solar radiation intensity, increasing the compressor speed can significantly increase the heating capacity of the system.
Transparent, stretchable and high-performance supercapacitors based on freestanding Ni-mesh electrode
Authors: Zhao Yaoyao , Jiang Zhouying , Weng Ya , Liu Yan-Hua
Published: March 2021

A high performance transparent and stretchable supercapacitor was formed by the electrochemical deposition of MnO2 on a freestanding Ni mesh and further integrated with an elastic substrate. The solid-state supercapacitor shows a high transparency of 62% at 550nm and superior areal capacitance of 34.8 mF/cm2 at the scan rate of 0.01 v/s. The supercapacitor device possesses a 98.8% capacity retention up to 30% strain. Moreover, the areal capacitance retention rate kept 87% after hundreds of stretching cycles at 30% strain.
Modeling energy system transformation policy in 2020 and 2030: A case study of Shandong Province
Authors: Zhang Xinwen
Published: March 2021

In recent years, Shandong Province has actively adopted policies and measures to reduce fossil energy consumption and achieve clean and low-carbon development. In order to explore the future energy system transformation and upgrading in Shandong Province, this paper use EnergyPLAN model to construct Shandong Province’s 2020 and 2030 energy structure standard scenarios and simulation scenarios for analysis. The results show that: under BAU (business-as-usual) scenario, in 2020, non-fossil energy consumption accounts for 7% of primary energy consumption, but it can only reach 8.67% by 2030, which is far from the policy goal (18%); to achieve the energy consumption goal promulgated by government, three alternative scenarios are then studied. Finally, this paper compares and analyzes the above two scenarios and proposes policy recommendations for the transformation of energy systems in Shandong Province.
Study on three-part pricing method of pumped storage power station in China considering peak load regulation auxiliary service
Authors: Song Xinfu , Zhai Xujing , Chen Weiwei , Xue Jingjie , Wang Pengchao
Published: March 2021

The existing operation mode of pumped storage power station in China has the problems of low profit and unable to fully reflect the value of various auxiliary services. In this regard, this paper puts forward a more reasonable and more suitable price mechanism of pumped storage power station in China. Firstly, this paper studies the pricing method considering dynamic depreciation. Then, on the basis of the feed-in tariff of thermal power units, the avoidable cost method is used to study the pricing method of grid price for pumped storage power station. Finally, based on the efficiency loss cost, generation opportunity loss cost and unit start-up and shut-down cost of pumped storage power station participating in peak load regulation auxiliary service market, a three-part electricity price mechanism is proposed. The electricity price mechanism proposed in this paper is helpful to correctly evaluate the benefit of pumped storage power station and promote the construction and development of pumped storage power station.
How does the urbanization level change in the Yangtze River economic belt, China? A multi-scale evaluation using DMSP/OLS nighttime light data
Authors: Xu Zhiyu , He Xiujuan , Chen Lin , Hu Xunxun , Tang Weiming , Li Jiahui
Published: March 2021

Based on DMSP/OLS nighttime light data, we select the Yangtze River Economic Belt (YREB) as the research area to evaluate the urbanization level of the YREB at provincial, regional, and county scales. First, we construct the compounded night light index (CNLI) based on the nighttime light data by extracting the integrated light intensity (I) and the built-up area (S) of the Yangtze River economic belt from 1992 to 2012, and we respectively calculate the CNLI of the YREB at the province, regional and county scales of the YREB such that we can comprehensively analyze the spatial and temporal distribution characteristics and dynamic changes of the process of urbanization in the YREB. Second, we construct two traditional urbanization level evaluation index models based on socio-economic statistics: The integrated urbanization level index model (IU) and the urbanization composite index model (Cf), which are used to respectively calculate the urbanization levels at the province, region, and county scales of the YREB. Finally, we establish a multi-scale urbanization model of CNLI, IU, and Cf in order to perform correlation analysis of CNLI, IU, and Cf on different scales. The results show that CNLI can objectively reflect the development status of urbanization level, and provide a new index and method for better monitoring the state of urban development and evaluating the annual change of urbanization.
A non-cooperative game theory based energy trading strategy of multi-microgrids
Authors: Liang Jianquan , Wang Panbao , Sun Wei , Zhang Jian , Xu Dianguo
Published: March 2021

This paper proposes an energy trading strategy based on non-cooperative game theory for multi-microgrids (MGs). According to whether the renewable energy generation can meet the load demand, the MGs are divided into consumers and providers. In order to reduce the operation cost, consumers compete to buy the energy provided by suppliers and changing the price of electricity purchase. The suppliers provide energy according to the priority factor. The energy provided by the provider is distributed to the consumer in proportion to the price offered by the consumer, and the income is allocated to the provider in proportion to the sales volume. On this basis, a non-cooperative game model composed of consumers is built, and the game model has Nash equilibrium is proved. Meanwhile, the Nash equilibrium solution through particle swarm optimization (PSO) algorithm is obtained. Finally, the feasibility and effectiveness of the energy trading strategy are verified by simulations.
Quantitative evaluation method of power supply reliability considering voltage sag
Authors: Du Pei , Lin Yan , Zhang Weijun , Liu Zhixuan , Lin Fang , Fang Xiaoling
Published: March 2021

Based on the analysis of the original quantitative evaluation system of power supply reliability, aiming at the influence of voltage sag on industrial users, a hierarchical quantitative evaluation system of power supply reliability considering voltage sag is proposed. The new index system aims to evaluate the reliability of the impact of voltage sag from the perspective of the structure, function and safety of industrial users. The specific evaluation methods are mainly composed of direct loss evaluation, indirect loss evaluation and potential safety hazard evaluation. Direct loss refers to the economic loss caused by the interruption of industrial process after the occurrence of voltage sag. Indirect loss refers to the economic loss caused by defective products due to the imperfect industrial production process. The potential safety hazard refers to the potential safety hazard of the production line where the important equipment is located after suffering voltage sag. This paper focuses on the rationality of quantitative evaluation with the principle of economic equivalence, the significance and internal relations of industrial user structure, function and safety index, and puts forward a reasonable calculation method. Through the case calculation, the layered evaluation results are consistent with the empirical conclusions, with applicability.
A Cournot game model for integrated energy service transaction in electric-gas coupled market
Authors: Gao Xiao , Li Chengren , Zeng Ming
Published: March 2021

Based on the analysis of the game behaviours of multi-energy players, for the purpose of maximining the utility of market entities, this study establishes a Cournot game model in the electricity-gas coupled market for multi-energy players, which include the pricing model of multi-energy players in Leader-Follower mode and the operation optimization model between multi-energy players and local energy system based on Stackelberg game. Through the example analysis, it is demonstrated that the master-slave model has good convergence properties and plays a vital role in the interaction process between different decision-making bodies and find the optimal strategy, which can provide important reference information for the decision-makers and has certain practical value.
Optimal planning method of renewable distributed generation for multiple prosumers participating in distribution networks
Authors: Tan Bin , Qiu Weijie , Ding Yujie , Shi Hujun , Yao Haotian , Shen Xiaodong
Published: March 2021

In the situation that distribution system operator (DSO) and multiple prosumers jointly invest distributed generation (DG) in the distribution network, it is difficult to achieve the balance of multi-agents interests under the requirements of security operation and privacy protection. To solve this problem, an optimal planning method of DG for multiple prosumers participating in distribution networks is proposed. First, the DG planning model of DSO and prosumers are constructed separately, and the network tariff dynamic updating strategy is proposed for the optimal guidance of multi-agent collaborative planning. Then, based on the collaborative planning framework for distributed autonomous decision-making of prosumers and the global coordination of DSO, a distributed solution method is proposed. Finally, the effectiveness of the proposed method is proved through the simulation results, the experiment proves that the network tariff updating strategy can better guide the multi-agent DG collaborative planning, and has better effects in balancing the benefit of prosumers and DSO.
Research on optimal operation strategy of fuel cell vehicle charging-discharging-storage integrated station
Authors: Yang Peng , Yu Xuan , Liu Gaowei
Published: March 2021

The construction of energy supply facilities supporting fuel cell vehicles is the basis for the development of fuel cell vehicles. Aiming at the large-scale environmental protection supply of hydrogen energy for fuel cell vehicles, this paper proposes a construction idea and function setting for a fuel cell vehicle integrated station. Then, an optimized operation model of the fuel cell vehicle charging-discharging-storage integrated station is established. The model takes the total operating cost of the integrated station as the objective function, and considers the power balance and constraints of the electric-hydrogen system in the integrated station. Nonlinear programming tool is used to solve the model. It is verified by calculation examples that the integrated station proposed in this paper can effectively improve the power grid’s peak and frequency modulation capabilities based on the total daily income of ¥25,431, and increase the renewable energy consumption rate from 48.0% to 84.6%.
Project classification and ordering optimization model of power grid company based on entropy weight and improved analytic hierarchy process
Authors: Wang Xi , Ye Qiang , Wang Haiyan , Qiao Yunchi , Cao Yuwei
Published: March 2021

At present, the power grid investment should be developed in the direction of reasonable scale, structure optimization and scientific timing. In this paper, starting from the comprehensive deepening of the precise investment of power grid companies, based on the analysis method of entropy weight order relationship combining subjective and objective, the paper constructs the project evaluation model of power Grid Company with five indicators of policy, urgency, risk, economy and strategy. The model adapts to the requirements of comprehensive policies and development reform, meets the characteristics of regional development, and supports the precise investment control of enterprises. It can ensure the realization of accurate investment in power grid, and give full play to the important role of power grid investment in stable growth, structural adjustment, making up for weaknesses and benefiting people’s livelihood.
Multi-domainsdispatching method for power system considering energy storage
Authors: Ge Weichun , Liu Debao , Liu Tao , Wang Shunjiang , Liu Junfa , Hu Lei
Published: March 2021

Reasonably arranging the matching of power sources is an effective mean to improve the capacity of new energy consumption. Using the dispatching characteristics of the transferable load of the energy storage systems can play an important role in the actual dispatch of the power system. From the perspective of flexible scheduling, a multi-domain scheduling method is proposed, which comprehensively considers the influence of factors such as load, wind power output random fluctuations and system adjustment capabilities, and redistributes it into three control domains. That is, the normal control domains with the goal of completely absorbing wind power, anomaly control domain where the energy storage systems needs to be used to absorb wind power, and the emergency control domain where there is no regulation ability and forced to abandon wind. To maximizing clean energy consumption, CPLEX software is used to optimize output and realize multi-domain green economic dispatch. The calculation example shows that this method can effectively improve the absorption capacity of clean energy.
Prospects of functionalized porous materials towards extraction of spent nuclear fuel radionuclides
Authors: Ochieng Adede Simon , Zhang Meng , Li Yaori , Mwangi Anselim Mwaura
Published: March 2021

Radioactive waste levels have continued to increase due to the growth and development of nuclear energy, industrial or medical radioactive use. In this regard, conventional radioactive waste generated by nuclear power plants cannot be ignored. Effective management of nuclear radioactive waste plays a vital role in alleviating negative impacts on the society and environment. Despite the progress that has been made concerning separation and recycling of spent nuclear fuel through the PUREX process, several gaps in knowledge still exist especially towards the development of a robust separation system based on solid-phase extraction using porous materials. Solid phase extraction is being viewed as one of the most convenient and effective approaches in the removal of cations in radionuclide solutions. This is due to its ability to increase the selectivity and sensitivity of the method as it permits discriminatory binding of analyte to a solid support where the analyte can be collected and thereafter eluted using small quantity of a different solvent. The review covers the current methods used in aqueous nuclear reprocessing, highlights their deficiencies and introduces the potential of applying solid-phase extraction in management of nuclear waste. This study gives the prospects of functionalized porous sorbent materials as solid support in solid-phase extraction of spent nuclear fuel elements.
The techno-economic evaluation of school integrated energy system based on G1-anti-entropy weight-TOPSIS method
Authors: Zhao Qingqi , Yu Changle , Liu Jun , Zhu Yuanda , Yang Lin , Zhao Hui , Wang Huaijian , Gao Shuyi
Published: March 2021

Scientific and reasonable evaluation system and method of technical economy are helpful to improve the technical economy of integrated energy system (IES). This paper analyzes the energy flow of the school integrated energy system (SIES), and constructs the techno-economic evaluation index system of the SIES from three aspects: technology, economy and environment. The evaluation index includes qualitative analysis index and quantitative analysis index. The techno-economic evaluation model of the SIES based on the G1-anti-entropy weight-TOPSIS method is constructed. The evaluation model reflects the subjectivity and objectivity of evaluation. It also overcomes the problem that the AHP method needs consistency test and high sensitivity of entropy weight method leads to the failure of index. Finally, a case study is conducted on a school in northeast China. The results of the analysis verify the feasibility of the evaluation index system and evaluation method. The evaluation system and evaluation method proposed in this paper can provide reference for the selection of SIES construction and operation plan.
Minimum reactive power loss optimization of power grid systems based on improved differential evolution algorithm
Authors: Xie Yejun , Liu Zhendong , Pan Yongchao , Li Fei , Jiao Taiming , Li Xiaojuan
Published: March 2021

With the expansion of power system scale, the operation of the power grid system has been greatly challenged. Reactive power optimization can make the power system operate safely and economically. In this paper, an improved differential evolutionary algorithm is applied to reactive power optimization of power system. We take the minimum power system loss as the objective function, the power balance condition as the equality constraint, the control variables and state variables as the inequality constraint conditions to establish the system model. Finally, IEEE30 bus and IEEE33 bus power system are selected to verify the effectiveness of the proposed algorithm.
Two-stage planning optimization of multi-scenarios integrated energy system considering energy reliability
Authors: Yu Changle , Zhao Qingqi , Liu Jun , Zhu Yuanda , Xu Minghu , Xu Haoran , Gao Shuyi , Wang Huaijian
Published: March 2021

The pace of economic society and globalization is accelerating, and the energy shortage and environmental pollution is increasing relatively. In order to comprehensive utilizing energy, this paper constructs an Integrated Energy System (IES) with electricity and gas in and electricity, cooling, and heat out, and solves the optimal configuration of this energy system through a two-stage planning optimization model. First, the two-stage planning optimization model based on particle swarm optimization (PSO) is established, and the capacity configuration plan of energy device is solved by the first stage. Then, Rayleigh probability distribution model is used to describe the uncertainty of wind power output, and two device reliability indicators are proposed to be added to the constraints. Finally, the objective function of the second stage is solved to obtain the optimal operation plan, and the planning optimal results of IES is obtained by repeated iterations of the two stages. Considering the energy storage devices, the Industrial and Living-official scenarios of IES are simulated and the results show that the proposed model is available to different scenarios and can reduce the costs of the energy system effectively and make sure the energy supply reliably.
Research on deployment method of edge computing gateway based on microservice architecture
Authors: Zhang Hai , Liu Zhengyi , Zhang Yaoyao , Zhan Shuguang , Yang Jianjun , Wang Guixiang , Sun Yufei
Published: March 2021

Traditional solutions that use servers or computers to deploy on-site are bulky and costly. The edge computing system can be deployed in a lightweight and flexible manner according to the actual needs of the site, so as to achieve the lowest cost while meeting the functional requirements. Based on this, this article proposes an edge computing system solution based on microservice architecture, discusses the overall framework of the system and the implementation of microservice architecture in edge computing systems, and introduces in detail an edge computing gateway device deployment method based on the Gaussian mixture model, which can optimize the number of deployed gateway devices while ensuring the load balance of each gateway device. Finally, the advantages of the deployment method are verified through experiments.
Flow characteristics and operation performance of the drag-type hydrokinetic rotor: a systematic review
Authors: Zhao Hexiang , Kang Can , Ding Kejin , Li Bing
Published: March 2021

The hydrokinetic rotor serves as a critical component in the system of hydropower utilization. Advantages of the drag-type rotor have been recognized while the disadvantages of low efficiency are appreciable. To improve the performance of the drag-type rotor, studies have been performed from multiple aspects. The present study summarized recent achievements of this rotor branch. Particular, emphasis was placed on the relation between flow characteristics and operation performance of the rotor. A systematic description of the recent achievements and methods pertinent to the drag-type rotor is expected to motivate more fruitful work, thereby extending the application of such a promising rotor.
Activated carbon fiber-supported nano zero-valent iron on Cr(VI) removal
Authors: Chen Shengwen , Li Meng , Wu Yundun , Wang Yanyun
Published: March 2021

Nanoscale zero valent iron (nZVI) was adsorbed on activated carbon fiber (ACF) for efficient removal of hexavalent chromium. The composite materials were characterized by XRD, SEM, FTIR, BET and XPS. Fe2+ was adsorbed by ACF and then restored by NaBH4. This sample was named ACF-nZVI-a. While Fe2+ was restored by NaBH4 and nZVI was adsorbed by ACF. That sample was named ACF-nZVI-b. BET analysis indicated that ACF-nZVI-a had a high specific surface area of 1087 m2/g, while ACF-nZVI-b had a low specific surface area of 928 m2/g, which indicated that it was easier for nZVI to go into the ACF pores than ionic condition Fe2+. Batch experiments showed that Cr (VI) removal rate was 98.9% for ACF-nZVI-b, which was higher than that for both ACF (33.7%) and ACF-nZVI-a (50.7%). Furthermore, the removal rate of Cr (VI) by ACF-nZVI-b showed strong dependence on initial solution pH. Low pH and initial Cr (VI) concentration favored both removal efficiency and rate constants. The reaction followed a pseudo first-order model under different initial Cr (VI) concentrations. The Cr (VI) removal was attributed to both the adsorption of ACF and the reducibility of nZVI, but the main cause was the reduction of nZVI. This study demonstrated that the ACF-nZVI-b had the potential to become an effective agent for the removal of Cr (VI) from polluted water.
Design and application of heat pipe heat exchange technology for supplying the anti-freeze heating in coal mines
Authors: Tang Weiwei , Yang Lizhong , Bai Yanbin , Yang Luhan
Published: March 2021

For designing the heat exchanger to supply necessary anti-freeze heating in the inlet wellhead of a mine, the specific heat demand there and the state of the art of the heat pipe technologies for waste heat recovery are reviewed. According to the existing conditions in a mine located in a cold region, a heat pipe heat exchanger was designed, the feasibility of this heat pipe heat exchanger was theoretically investigated, and the influence of the heat exchange efficiency on the effect of the heat exchanger was analyzed. Then the necessary guarantee measures and the implementation scheme for sufficient heat supply under the extremely cold weather conditions were pointed out. Finally, the feasibility of this heat pipe heat exchange technology is verified by the actual preliminary operation performance and the key technical problems of its application are clarified.
Optimization of horizontal well fracturing mode in Gaotaizi tight reservoirs of L26 well block in Daqing Oilfield
Authors: Liu Lifeng , Bai Xijun , Li Fengfeng , Wang Xin
Published: March 2021

The tight reservoir of the Gaotaizi oil layer in the L26 well area of Daqing Oilfield is a typical sand sheet deposit, with complex geological conditions. It is difficult to evaluate the production of horizontal wells in tight reservoirs with different well layout and fracturing operation scales, and the reasonable fracturing mode is unclear. Based on the study of reservoir characteristics and fracturing parameters in the area, multi-scale and multi-media well group models of sand sheet facies deposition in the Gaotaizi reservoir were established, and the reasonable well spacing under the mode of parallel and staggered fracture distribution was studied by numerical simulation. The results show that the production of horizontal wells with staggered fractures is slightly higher than that with parallel fractures. The well spacing of wells with parallel fractures is 600m, and the optimal well spacing under staggered fracturing is 500m. The results provide a basis for the optimal design of tight oil horizontal wells in the Gaotaizi reservoir of Daqing.
Molecular dynamics simulation of promoting nucleation of CO2 hydrate by ethylene oxide and tetrahydrofuran
Authors: Yang Xuefeng , Du Shuai , Hao Yongchao , Xu Jiafang
Published: March 2021

Storing carbon dioxide in the form of hydrates is a meaningful way to reduce carbon emissions, which is of great significance to the replacement of extracted hydrates, the storage and transportation of gases, and the safety of oil and gas pipelines. In this paper, the molecular dynamics simulation was used to study the effects of ethylene oxide (EO) and tetrahydrofuran (THF) on the nucleation of carbon dioxide hydrate. The result shows that both EO and THF can promote the nucleation of carbon dioxide hydrate and shorten the nucleation time. For the same number of molecules, THF has a better promotion of nucleation of CO2 hydrates than EO. It was also found that the addition of THF and EO promoted the formation of sII type cages in the system. The study provides a microcosmic perspective for the enhancement of hydrate nucleation by additives.