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- S. ENERGY CONSTR. is a Peer-Reviewed journal started in 2014 which declared a Gold Open Access journal and dedicated to the free sharing and dissemination of knowledge in energy construction.
- 2024，indexed by COAJ (China Open Access Journals)
- 2023, indexed by Scopus
- 2022, indexed by EBSCO Research Database
- 2021, indexed by DOAJ(Directory of Open Access Journals)
About Journal
Bimonthly Publication，Start in 2014.12
Supervisor：China Southern Power Grid Digital Media Technology Co., Ltd.
Sponsor：
China Energy Engineering Group
Guangdong Electric Power Design Institute Co., Ltd.
Editor：Editorial Board of S. ENERGY CONSTR.
Publisher：Energy Observer Magazine Co., Ltd.
Honorary Chairman：DU Xianwan
Chairman：PENG Xueping
Co-Editor-in-Chief：YANG Yongping, FAN Yongchun
Associate Editor：ZHANG Chunwen
Editorial Director：ZHENG Wentang
Address：1 Tianfeng Road, Science City, Huangpu District, Guangzhou, P. R. China
Tel：+86-20-32119015；32119373
ISSN 2095-8676
CN 44-1715/TK
CODEN: NFNYJK
Email：nfnyjstg@gedi.com.cn
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RSSThe call for papers focuses on academic frontiers and hot issues in the fields of "carbon peak and neutrality" and special columns, features, and special issues will be published irregularly.
- Special Issue of Large-scale Renewable Energy Hydrogen Production Technologies
- Special Issue of "Controlled Nuclear Fusion Power Engineering Technology" in May 2024
- Special Issue of ''Electric Power and Meteorological Technology'' in Jan. 2024
- Special Issue of ''DC Transmission Technology for New Power System Construction'' in Sep. 2023
- Special Issue of ''Offshore Wind Power Engineering Technology'' to be Published in Jul. 2023
- Special Issue of ''Hydrogen Energy Technology'' to be Published in May 2023
- Special Issue of "New Power System and Energy Storage Technology" to be Published in Dec. 2022
- Special Issue of "Low-Carbon Collaborative Transformation Technology for Thermal Power Generation Units" to be Published in Sep. 2022
Articles in press have been peer-reviewed and accepted, which are not yet assigned to volumes /issues, but are citable by Digital Object Identifier (DOI).
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Accepted Manuscript
, Available online ,
doi: 10.16516/j.ceec.2024-364
Abstract:
Introduction In order to improve the deep peak shaving ability of coal-fired units, a deep peak shaving system for coal-fired units coupling non-afterburning compressed air energy storage is proposed in this paper. Method The system stored electric energy by compressing air during the low load period of the power grid to reduce the external power supply, and released the electric energy, stored by compressing air, during the peak load period of the power grid to increase the power supply. Result Taking a 2×350 MW supercritical primary intermediate reheat coal-fired unit as an example, the calculated internal rate of return on project capital is 7.45%, indicating that the system has a certain level of economic viability. Conclusion At this stage, coal-fired units coupling non-afterburning compressed air energy storage may have some disadvantages in terms of initial investment, and this scheme can significantly improve the bi-directional peak shaving ability of coal-fired units. Moreover, it does not require modifications to the existing equipment of the units, thus avoiding adverse effects on their operation. It has a certain application prospect in the field of deep peak shaving of coal-fired units.
Accepted Manuscript
, Available online ,
doi: 10.16516/j.ceec.2024-287
Abstract:
Introduction International Hydrogen Council predicts that hydrogen energy will account for 18% of the total global end-use energy demand by 2050. In the technical path of green hydrogen preparation, the electricity cost of photovoltaic (PV) power generation is a key factor affecting the cost-effectiveness of hydrogen production by water electrolysis. Method Based on the solar resource data of typical regions in China, a levelized cost of energy (LCOE) calculation model was constructed to analyze the PV power generation costs at current and limit module costs, and quantify the marginal impact of photoelectric conversion efficiency improvement on LCOE. Result The results indicate that: with an annual effective power generation hours of 1 200, LCOE for crystalline silicon photovoltaic cell system can be reduced to CNY 0.133 per kWh; However, the LCOE threshold of CNY 0.1 per kWh can be achieved for perovskite solar cell, crystalline silicon-perovskite tandem cell and dual tandem cell system with higher theoretical conversion efficiency when the annual power generation hours are 1 008, 1 092 and 864 respectively. When the LCOE for PV power generation is less than CNY 0.1 per kWh, the cost of hydrogen production by water electrolysis can be reduced to CNY 6.16 per kg. Conclusion With the reduction of module cost and the improvement of conversion efficiency, the LCOE for PV power generation in more than 90% of areas in China will have the potential to break through RMB 0.1/kWh. Within this cost range, green hydrogen will show a competitive advantage in production cost compared with traditional grey hydrogen and is expected to become the mainstream hydrogen source. This paper provides a quantitative basis for the industrialization of photovoltaic hydrogen production technology, and has an important reference value for optimizing the transformation path of energy structure and realizing the coordinated development of environmental benefits and economic benefits.
Accepted Manuscript
, Available online ,
doi: 10.16516/j.ceec.2024-297
Abstract:
Introduction The development of information technology leads the development trend of the new era. Information technology promotes the progress of nuclear power generation technology to intelligentization and even smartization, while also ensuring the safe development of nuclear power generation. Method The positioning association of information, nuclear power generation, and the intelligentization of nuclear power generation was provided. The application of information technology in future nuclear power generation was studied. The development trend of advanced nuclear power generation was analyzed. Result The future nuclear power generation should first be information-based nuclear power generation, followed by intelligent nuclear power generation, and then possibly smart nuclear power generation. The characteristics of 5G low delay can make the nuclear power generation system more accurate, and the nuclear system can be accurately adjusted to operate faster and respond in time. Cloud computing can also find problems in nuclear power generation's complex mass of data. Big data can analyze the root causes of problems in a timely manner. Quantum technology can enhance the core fuel function. Artificial intelligence machine data capture and neural networks learn to process and apply information more precisely. Conclusion Informationization is also a new quality productivity revolution, and information technology promotes the progress of nuclear power generation technology to intelligent development. The intelligence of nuclear power generation is the future trend of advanced nuclear power generation development. The upgrading of information technology is the leading driver of nuclear power generation. Ensuring nuclear power generation safety requires the assistance of information. Network information technology is the central link to build a comprehensive nuclear and solar energy system.
Accepted Manuscript
, Available online ,
doi: 10.16516/j.ceec.2024-289
Abstract:
Introduction The coordinated development of electricity and hydrogen is a key pathway to achieving dual carbon goals and serves as a crucial support for building a new power system. To promote the sustainable development and market promotion of China’s hydrogen energy industry, the multi-dimensional business operation models and development strategies for electric-hydrogen complementary and collaborative systems are proposed. Method Firstly, the paper comprehensively reviewed the development trends in the electric-hydrogen field both domestically and internationally, and summarized the current status of typical electric-hydrogen projects. Secondly, the profitability mechanisms for electric-hydrogen complementary and collaborative system were analyzed, including the research on diverse hydrogen sales models, the exploration of electricity market revenue, and the assessment of carbon reduction economic value. Based on this basis, multi-dimensional business models for the electric-hydrogen complementary and collaborative system tailored to China's national conditions were proposed, and profitability was calculated under the boundary conditions such as different market conditions and electricity price mechanism. Result The study shows that the electricity pricing mechanism in the spot market significantly guides hydrogen storage, helping to compensate for the efficiency losses in the electric-hydrogen conversion. Integrated utilization of electrolyzers and fuel cells for ancillary services is one of the key strategies to enhance profitability. Coordinating renewable energy hydrogen production with hydrogen sales can substantially improve overall economic benefits, and is also an effective transition from hydrogen sales profitability strategies to future electricity market revenues. Conclusion Based on China's energy endowment characteristics and regional distribution, it is recommended that different regions explore the development of business models for electricity-hydrogen complementary and coordinated systems tailored to local conditions. These include clarifying market-oriented policy directions, guiding large-scale development, and expanding diverse end-use applications.
Accepted Manuscript
, Available online ,
doi: 10.16516/j.ceec.2024-278
Abstract:
Introduction The construction of beautiful China should show the beauty of modernized engineering, and more importantly, it should rely on the excellent traditional Chinese culture. The paper aims to study the design method to improve the existing industrial buildings with culture and aesthetics, which is limited by process modeling and engineering economy. Method Through case study and engineering practice, we studied the aesthetic design cases of power projects at home and abroad, summarized the three perspectives of traditional regional culture, scientific and technological innovation culture, and diversified fusion culture, and applied them to the design ideas of "Distant Shadows - Rising Clouds - Sky" for the new 2×1000 MW project of CHN Energy Yueyang Power Plant. Result Through the design practice of typical projects, the engineering aesthetic design method of "cultural empowerment expression", "innovation-driven design" and "sharing and integration development" is refined. Conclusion We expect to take the Yueyang Power Plant as a starting point to explore the feasible way for culture as a conceptual starting point and innovation foothold to empower engineering aesthetics, especially in the overall planning and architectural design of thermal power plants.
Accepted Manuscript
, Available online ,
doi: 10.16516/j.ceec.2024-044
Abstract:
Introduction For the oxygen ion conductive solid fuel cell fueled by hydrogen, the paper proposed a SOFC-"GT+ST" system with the cathode and anode of the fuel cell entering the gas turbine and steam turbine respectively, and analyzed the impact of different parameters on system efficiency, providing reference opinions for hydrogen fuel cell and turbine coupling systems. Method A system model was established using the software Ebsilon. The model was compared with the SOFC-GT system under the given parameters. Additionally, the study investigated the effects of fuel utilization, compressor pressure ratio, air flow and SOFC inlet working fluid temperature on the total power generation efficiency of SOFC-"GT+ST" system. Result The results show that compared with the SOFC-GT system, the total power generation of the SOFC-"GT+ST" system increases to 73.3 MW, representing a 5.74% improvement over the original system, with a power generation efficiency of 60.13%. The fuel utilization of the fuel cell, the compressor pressure ratio, the cell inlet temperature and the air flow rate all affect the system’s total power generation efficiency. Among these factors, there is an optimal value for fuel utilization and a reasonable range for the air flow rate. Additionally, higher cell inlet temperature and compressor pressure ratio lead to higher power generation efficiency of the system. Conclusion Under the structure and parameters defined in this study, the optimal value of fuel utilization of fuel cell is 0.85, and the air flow value should be between 35 and 39 kg/s. The improved system can effectively enhance the total power generation efficiency of SOFC and turbine combined power generation system. The results of this study provide a reference for the selection of system parameters.
Accepted Manuscript
, Available online ,
doi: 10.16516/j.ceec.2024-031
Abstract:
Introduction With the increase of renewable energy capacity installed each year, hydrogen production by water electrolysis has become an important way to consume renewable energy. Method This paper integrated the classical electrochemical model, conservation relationship, and empirical formula of alkaline electrolyzer to investigate the impact of temperature, pressure, current density, and other factors on the performance of water electrolysis system for hydrogen production. By analyzing the impact mechanism in relation to the electrolyzer structure, key materials, and operation conditions the study identifies a direction for optimizing the performance of current water electrolysis system for hydrogen production. Result The studied performance parameters include hydrogen yield rate, global efficiency, cell voltage, and hydrogen content in oxygen. The study found that increasing current density and raising the temperature both enhance the hydrogen production rate, while changes in pressure have a relatively minor impact. The paper combines physical mechanisms and practical operating experience to analyze the validity of some empirical parameters in the model. Conclusion Optimizing the electrolyzer structure and boosting the performance of catalysts are crucial for improving the current density. Operating the electrolyzer at too high a temperature exceeds the tolerance of the equipment materials, while operating at too low a temperature increases system energy consumption. Therefore, a balanced consideration is necessary. Increasing pressure means higher requirements for the equipment's sealing and the performance of basic materials, but producing high-pressure hydrogen also provides more options for downstream applications, potentially reducing investment in downstream compression and storage systems.
Accepted Manuscript
, Available online ,
doi: 10.16516/j.ceec.2024-124
Abstract:
Introduction The Hunan-Guangxi Corridor, rich in wind resources, is a channel for cold air to move southward into Guangxi. Every winter, there are often severe weather conditions such as low temperatures and freezing, which can lead to problems such as ice coating on wind turbine blades, changes in material and structural properties, and changes in load, resulting in reduced service life of wind turbines and affecting power generation capacity. In Guangxi, the impact of cold wave and low temperature weather on wind power generation has received widespread attention. Low temperature conditions have a significant impact on the operation phase of wind farms. Currently, there are few studies that statistically analyze the operation of wind turbines under low-temperature conditions and their impacts. Method This paper utilized real-time observation data and 0.25 × 0.25 reanalysis data from the European Center ERA5, as well as data from wind energy companies in Guangxi on ice induced shutdowns and wind curtailment power losses. An analysis was conducted on the impact of the low temperature and freezing weather from December 15 to 24, 2023 on the high-altitude wind power generation in northern Guilin. Simultaneously, the formation mechanism and forecasting techniques of Guilin's severe low temperature and freezing weather were analyzed. Result It is found that there is a correlation between environmental temperature, air humidity, and wind power loss, and a correlation formula is derived. Conclusion This research provides a foundation for further prediction and early warning of low temperature weather and wind power generation in Guilin high-altitude wind farm. Using temperature forecasting products from numerical forecasting, the number of daily shutdowns and power losses in the future can be predicted in advance, assisting in wind power forecasting. At the same time, high-precision freezing disaster weather forecast and warning can optimize customer resource allocation, reduce customer property losses, and ensure personnel and equipment safety.
Accepted Manuscript
, Available online ,
doi: 10.16516/j.ceec.2024-231
Abstract:
Introduction In recent years, under the continuous promotion of carbon peaking and carbon neutrality policy, offshore wind power hydrogen production has made great progress in China as an important technology for renewable hydrogen production. The article reviews the technological routes, development status and challenges in the offshore wind power hydrogen production industry within China. Based on the analysis, it presents targeted countermeasures and recommendations, aiming to provide a foundation of insights and references for the future application and advancement of offshore wind power in the region. Method Through an investigation of the research and development progress in offshore wind power hydrogen production technologies both domestically and internationally, the technological advancements and constraints were analyzed across three key dimensions: offshore wind-to-hydrogen systems, electrolytic hydrogen production technologies, and offshore hydrogen storage and transportation solutions. By evaluating the current overall development status of the industry, the current development advantages and constraints of the industry were analyzed from the aspects such as policy frameworks, market structures, and technological pathways. Result The analysis highlights the existing strengths and development constraints of the industry. Notably, the industry demonstrates a diversified development trajectory, positively influencing the renewable hydrogen sector and promoting continuous advancements in electrolyzer capacity. Nonetheless, several critical challenges persist, including the absence of breakthroughs in core technologies, dependence on imported key components, elevated life cycle costs, and gaps in regulatory and policy support. These factors collectively represent significant barriers to the sustained growth and advancement of the offshore wind-powered hydrogen production industry. Conclusion It is concluded that in the process of actively developing the offshore wind power hydrogen industry, the hidden bottleneck constraints should be guarded against, from the perspective of policy standards, industrial layout, core technology, etc., China should scientifically design and reasonably layout, to promote the development of the combination of offshore wind power and hydrogen industry, and to help achieve the carbon peaking and carbon neutrality goals.
Accepted Manuscript
, Available online ,
doi: 10.16516/j.ceec.2024-244
Abstract:
Introduction As one of the new energy storage technologies, vertical gravity energy storage has become a research hotspot in the field of energy storage because of its high safety and environmental friendliness. Systems based on the traditional rotary motors can only transport a single heavy load and cannot meet the various power level requirements of the power grid by changing the number of different loads transported. The application of linear motors, however, can effectively address this issue. Therefore, the vertical gravity energy storage systems using linear motors have garnered significant attention. Method This paper introduced the basic working principle of vertical gravity energy storage systems using linear motors and summarized the current system structures and the design of linear motors within these systems. Result The results show that due to the long-distance movement of the vertical gravity energy storage device and the large mass of the load block, a linear motor with large thrust and magnet and coil windings mounted on the mover is required. Current research focuses on consequent-pole linear vernier hybrid machines, flux-switched permanent magnet linear motors, and linear switched reluctance motors. All three types of motors are suitable for vertical gravity energy storage systems due to their unique characteristics and advantages. Conclusion It is evident that compared with the traditional rotary motor systems, systems using linear motors offer numerous advantages, and will gradually become the mainstream solution for vertical gravity energy storage technology. Given the system characteristics of vertical gravity energy storage, the selection of linear motors is crucial. If the structure of linear motors is specifically designed for vertical energy storage systems, the excellent performance of the storage system will be better leveraged to promote the widespread application of vertical gravity energy storage technology.
Accepted Manuscript
, Available online ,
doi: 10.16516/j.ceec.2024-319
Abstract:
Introduction With the proposal of the "carbon peak" and "carbon neutrality" goals, the global push for the transformation of the energy structure is accelerating the construction of new power systems dominated by renewable energy. The intermittency and instability of the new energy sources connected to the grid place higher demands on energy storage technologies. Gravity energy storage, as a novel physical energy storage technology, has broad prospects for development. However, its output power lacks stability, and the power curve urgently needs to be optimized. Method This paper analyzed the operation process of a shaft-based gravity energy storage system and established physical, efficiency, and power models. Based on these three fundamental models, an overall model for multi-objective optimization was developed with the goals of stabilizing power output and minimizing fluctuation rates. Constraints were set by combining the three models with real-world conditions to determine the optimal parameter configuration for the weight during operation. Result Simulation verification of the energy storage system shows that the established overall model effectively optimizes the output power curve at the grid demand power levels of 30 MW, 40 MW, and 50 MW. The optimized fluctuation rates are 3.9%, 4.6% and 8.7%, respectively. Conclusion Based on the proposed optimization model, under the condition of constant medium mass of the weight, the output power fluctuation increases as the grid demand power level rises. When the power level increases by 20 MW, the power fluctuation rate increases by 4.8%. Under the condition of constant grid demand power level, the output power fluctuation rate decreases as the medium mass of the weight increases. When the mass of the weight increases from 80 t to 150 t, the power fluctuation rate at 40 MW decreases by 4.2%. The model demonstrates good feasibility and provides valuable guidance for future vertical gravity energy storage projects.
Accepted Manuscript
, Available online ,
doi: 10.16516/j.ceec.2024-247
Abstract:
Introduction As a new type of energy storage means, shaft-type gravity energy storage technology has unique advantages of low environmental pollution, low construction cost and high efficiency, and has a wide application prospect, but the research on the power generation characteristics and influencing factors of the system itself is still imperfect. The power generation efficiency of the shaft-type gravity energy storage system is one of the important indicators of the energy storage system. Method In this paper, through the mathematical modeling of the efficiency model of the shaft-type gravity energy storage system, the influencing factors of efficiency in case of three different heavy block fall curves were studied, and the influence trend of these factors on the power generation efficiency of the system was explored through simulation experiments, and then the efficiency characteristics of the three velocity curves were compared and analyzed. Result The results show that the falling speed has a significant effect on the efficiency of the system, and the power generation efficiency can be improved by reducing the speed appropriately. The height of the shaft and the mass of the heavy block have little effect on the efficiency of power generation. For the three velocity curves, the power generation efficiency of trapezoidal and triangular velocity curves was less affected by other factors, while the parabolic velocity curve was more sensitive to the influence of other factors, and the power generation efficiency was relatively smaller, and the trapezoidal velocity curve has the highest system efficiency under the same conditions. Under the premise of heavy blocks with large weights, the power generation efficiency of the three velocity curves was less affected by other factors. Conclusion Therefore, using heavy blocks with large weights, reducing the maximum falling speed of heavy blocks, and adopting the trapezoidal velocity curve can significantly improve the power generation efficiency to achieve better system performance.
Accepted Manuscript
, Available online ,
doi: 10.16516/j.ceec.2024-219
Abstract:
Introduction In the context of the "30·60" carbon peak and neutrality targets, this paper’s purpose is to address the problem of poor power balance performance in integrated energy systems caused by the uncertainty and discontinuity of renewable energy. Method This paper constructed a hydrogen-electricity coupling link that included hydrogen production from electrolyzed water coupled with gas hydrogen blending technology and hydrogen storage, established a punishment mechanism for wind and solar curtailment, and constructed an optimization and scheduling model for integrated energy system that included hydrogen-electricity coupling link. To address the problems of getting stuck in local optima and slow convergence speed during the solution process, the Pied Kingfisher Optimizer (PKO) algorithm was introduced. Result The model aims to minimize the total system cost as the objective function, and solves for the optimal scheduling results of the output of each energy network unit; Compared with traditional optimization algorithms, PKO has a faster convergence speed and is better able to achieve the goal of global optimal solution. Conclusion Case analysis indicates that using the model and method proposed in this paper reduces the total cost by 15.04% and 6.99% respectively compared to other schemes, effectively improving the utilization level of new energy in the integrated energy system, reducing the total system cost, and making it more economical.
Accepted Manuscript
, Available online ,
doi: 10.16516/j.ceec.2024-218
Abstract:
Introduction With the proposal of "carbon peak, carbon neutrality" goal, the concept of low-carbon environmental protection has been raised to a new height. As energy terminals, the parks have become an important carrier of low-carbon emission reduction. Method Aiming at the operation economy of the integrated energy system in the parks with electricity-gas-heat coupling and the problem of wind and light curtailment, an operation method of the integrated energy optimization in the parks based on electricity-to-gas （P2G） conversion was proposed. The electrolysis tanks, methane reactors and hydrogen fuel cells were introduced to replace the traditional P2G, providing an effective method for new energy consumption. Result In order to further reduce the carbon dioxide emissions in the parks, a stepped carbon trading mechanism based on the carbon excess rate was introduced. Taking the daily operating cost of the parks as the optimization target, an optimal scheduling model was established to set constraints to satisfy the supply/demand balance of the integrated energy system and the operation of the equipment in the parks. The results show a 12.4% reduction in system operating costs, a 16.2% reduction in system carbon emissions, and a 29.3% and 25.7% increase in wind and photovoltaic utilization, respectively. Conclusion The CPLEX business solver is used as a solution, and the proposed strategy is compared and verified to effectively improve the economy and low carbon of the integrated energy system in the parks by setting up multiple operation scenarios, which provides a strong support for the parks to achieve the goal of carbon emission reduction.
Accepted Manuscript
, Available online ,
doi: 10.16516/j.ceec.2024-140
Abstract:
Introduction The frame gravity energy storage system has a wide range of application prospects due to its high economic benefits, low system costs, and unrestricted geographical conditions. Method The paper studied the profit variation rules of the frame gravity energy storage system throughout its life cycle in detail by applying the leveled net present value of electricity (LNPVE) model. The paper, based on the net present value of capital flow in gravity energy storage systems, first built a levelized revenue of electricity (LROE) model which includes initial investment, discount rate, feed-in tariff, and government subsidies; then, built the LNPVE model on the basis of the LROE model and the levelized cost of electricity (LCOE) model; and finally explored the changes of LCOE, LROE, LNPVE, total net present value income and total discounted cost when the discount rate, feed-in tariff, service life and charge-discharge efficiency of the system change, to comprehensively consider the impact of different parameters on the economic efficiency of the system. Result The increase in the discount rate, service life, and charge-discharge efficiency of the system will improve the economic efficiency of the system. In addition, as the service life of the system increases, the LNPVE of the system decreases while the total net present value income increases. Therefore, it is more appropriate to comprehensively consider multiple factors when evaluating the economic efficiency of the system. Conclusion The LNPVE model studied here can provide a reference for the construction and profit analysis of frame gravity energy storage systems.
Accepted Manuscript
, Available online ,
doi: 10.16516/j.ceec.2024-139
Abstract:
Introduction Gravity energy storage, as a new form of energy storage, plays an increasingly important role in balancing power supply and demand, responding to intermittent energy fluctuations, and other aspects of the power system. Method Focusing on the gravity energy storage system based on ground structure and slope gravity energy storage, the paper analyzed in detail the research status of these two forms of gravity energy storage both domestically and internationally. Firstly, compared with traditional energy storage forms, the working principle and advantages of gravity energy storage were provided. Then, the research status and economic cost analysis of the gravity energy storage system based on ground structure and slope gravity energy storage structures were presented. Then, two typical types of slope gravity energy storage system structures, i.e. mountain mining car type and mountain cable car type, were introduced in detail, and the effect of parameters such as slope and weight on system efficiency and cost performance was explained. Finally, prospects and suggestions were given for the technical characteristics of gravity energy storage systems. Result The gravity energy storage system based on the ground structure is stable and has a high initial investment cost, making it suitable for users with large power fluctuations. The slope gravity energy storage features low construction cost and simple operation and is suitable for users in high mountain terrain with low power demand. Conclusion With the gradual maturity of gravity energy storage technology and its continuous cost reduction, it will play an important supporting role in the construction of power systems as a new type of energy storage in the future.
Accepted Manuscript
, Available online ,
doi: 10.16516/j.ceec.2024-108
Abstract:
Introduction During the hydrogen production process at hydrogen refueling stations, the mixture of ethanol and hydrogen can easily form a combustible gas, which may explode if ignited by sparks or high temperatures. In order to reduce the risk of explosion during hydrogen production and storage at hydrogen refueling stations, experimental research is essential. Method The explosion characteristic parameters were analyzed for hydrogen-ethanol-air mixture with different equivalence ratios and ethanol blending ratios at 1 bar and 400 K. By calculating the flammability limit and deflagration index of mixed gas, the degree of explosion hazard was evaluated, and effective safety measures were formulated to reduce the risk of explosion. Result The experimental research results show that an increase in the equivalence ratio will shorten the explosion time, making it ultimately tend to a stable value. The stable explosion times corresponding to hydrogen volume fractions (30%, 50%, 70%) are 0.03 s, 0.025 s, and 0.019 s. The maximum explosion pressure, maximum pressure rise rate, and deflagration index all increase and then decrease with the increase of equivalence ratio, reaching their peak at an equivalence ratio of 1.3. The flammability limit of the mixed gas continues to decrease with the addition of ethanol, and the decrease in UELmixture (upper flammability limit of mixture) is significantly higher than that in LELmixture (lower flammability limit of mixture). In addition, the maximum pressure rise rate and deflagration index show a significant decreasing trend with the addition of ethanol, and the maximum deflagration index calculated for this research is 11.85 MPa·m/s. Conclusion The research results have revealed the effect of equivalence ratio and blending ratio on the explosion characteristics of mixed fuels, providing a solid theoretical basis for reducing explosion risks in hydrogen production and storage processes at hydrogen refueling stations.
Accepted Manuscript
, Available online ,
doi: 10.16516/j.ceec.2024-099
Abstract:
Introduction The safe operation of nuclear power equipment is crucial for nuclear power plants (NPPs), and the losses caused by accidents are immeasurable. Therefore, effective anomaly detection for nuclear power equipment is necessary. Considering the limitations of fixed thresholds and manual detection methods, which are difficult to adapt to the dynamic changes in time series data, this paper proposes an anomaly detection method based on POT for multivariate statistical processes. Method This paper adopted PCA to construct an anomaly detection model, where the SPE statistic of the model served as the initial threshold for the POT algorithm. Subsequently, the portion exceeding the initial threshold was fitted with a generalized Pareto distribution to determine the final dynamic threshold. An anomaly warning was issued when the anomaly score exceeded the final threshold. By combining multivariate statistical process control (MSPC) with extreme value theory (EVT), this method used MSPC to discover anomalies in the operating data of NPPs quickly and improved the sensitivity and reliability of anomaly detection by modeling and analyzing extreme events, so that it can quickly detect anomalies in high-dimensional operating data of NPPs. Result In the simulation experiment results, the proposed method has a higher accuracy and recall rate than conventional multivariate statistical and POT methods. In experiments with actual operating data from different equipment in NPPs, the method's effectiveness in anomaly detection has been demonstrated. Conclusion By combining MPSC with EVT, the anomaly detection method proposed in this paper can not only detect anomalies caused by changes in data relationships but also avoid false detection in traditional MSPC by determining the final threshold using the POT method. This method can handle high-dimensional time series operating data of NPPs, improve the efficiency of anomaly detection, ensure the safe and efficient operation of NPPs, and improve their economic benefits.
Accepted Manuscript
, Available online ,
doi: 10.16516/j.ceec.2024-180
Abstract:
Introduction The study aims to comprehensively and systematically explore the current development status of molten salt reactor (MSR) technology, clarify the advantages of MSR as the fourth-generation nuclear power technology, and analyze the major challenges facing its commercialization. By analyzing the development history, technical classification, and research and development progress in various countries, the study provides valuable references for the future development of MSR technology. Method Using the research methods of literature review and comparative analysis, the development history of MSR technology was reviewed, the different types of MSR technology were classified in detail, and the latest progress in MSR technology research and development in countries such as the United States, China, Russia, France, and Canada was deeply analyzed. Meanwhile, based on actual cases such as the MSRE experimental reactor and the TMSR project, the key technical progress and major challenges of MSR technology were discussed. In addition, the impact of international cooperation and technological innovation on the development of MSR technology was also analyzed. Result It is found that MSR technology has been widely concerned globally due to its advantages of high safety and high fuel utilization rate. The United States has verified the engineering feasibility of MSR through the MSRE experimental reactor, and China has made important progress in molten salt preparation and purification in the TMSR project. Russia, France, Canada, and other countries have also made significant achievements in the field of MSR technology. However, the commercialization of MSR technology still faces many challenges, including supply chain construction, fuel supply, regulatory framework adaptation, waste treatment, safety assurance measures, and complex maintenance and operation. Conclusion Although MSR technology faces many challenges, its advantages in safety, fuel utilization rate, and design flexibility give it broad development prospects. International cooperation and technological innovation are key factors in promoting the progress of MSR technology. With the continuous advancement of related technologies, these challenges are gradually being resolved. In the future, MSR technology is expected to become an important support for the global energy structure transformation, playing a crucial role in improving fuel utilization, reducing nuclear waste generation, and enhancing reactor safety. As research deepens and technology matures, MSR technology is expected to achieve commercialization and contribute to the global clean energy transition.
Accepted Manuscript
, Available online ,
doi: 10.16516/j.ceec.2023-308
Abstract:
Introduction Wind turbine generator systems (WTGS) are prone to various types of failures due to the harsh operating environment. For the main bearing, a central component of the transmission system, it is difficult to detect and evaluate its early failure, and offshore operations are restricted by limited weather windows. How to accurately evaluate the operating conditions of the main bearings of offshore units has become a major difficulty for the industry. Method The study focused on the operation condition of the main bearing of an offshore direct-drive generator with a capacity of 7 MW. The transmission process of the wind wheel load in the transmission chain was deduced by the theoretical formula, and the radial load and axial load on the main bearing were obtained. Through the finite element calculation and analysis of the main bearing, the load distribution within the bearing raceway was obtained, which was mutually verified with the theoretical derivation, and the position of the vibration monitoring point was determined preliminarily. Result Finally, according to the position of the bearing measuring point, the vibration monitoring is carried out in the WTGS site, and a clear time-domain vibration curve is obtained. The vibration monitoring results such as the effective value of the vibration of the main bearing, the response frequency of the impact signal, and the acceleration envelope characteristics are analyzed. Combined with the detection results of the grease composition inside the bearing, the damage degree of main bearing's specific components is qualitatively judged. Conclusion This study has identified the measuring point position of the main bearing of multi-megawatt direct-drive offshore WTGS, and accurately assessed the operating condition of the main bearing, which can provide technical support for design and maintenance personnel.
Accepted Manuscript
, Available online ,
doi: 10.16516/j.ceec.2024-058
Abstract:
Introduction Energy is widely considered the fuel of industry and the lifeline of the national economy. The impressive economic and development achievement of Guangdong after reform and opening up relied heavily on the support and logistical backing from the development of its energy industry. Being a major energy consumer with limited resources and thus featuring low self-sufficiency in energy, Guangdong has always faced the threat of energy scarcity. After decades of development and transition, its energy sector is gradually evolving into a diversified new energy system composed of traditional thermal power, nuclear power, offshore wind power, and photovoltaic power generation. It has shifted from being a limiting factor in economic production to becoming an integral component of the province's high-tech manufacturing industry chain. Analyzing the economic contribution of energy sector from a macroeconomic perspective holds practical significance for formulating scientific energy industry development plans and promoting high-quality, coordinated development of energy and economy in Guangdong. Method Firstly, a research dataset was established by integrating the indicator data that represent the development of the energy sector and economy in Guangdong. Subsequently, both the vector autoregression model and the Feder two-sector production function model were employed to conduct a quantitative analysis of the overall economic contribution and spillover effects of Guangdong's energy sector. Result The analysis indicates that, during the late industrialization phase, a mutually reinforcing relationship existed between the energy sector and economic development in Guangdong. The production of the energy sector makes a significant overall contribution to economic growth, with notable spillover effects. However, the economic stimulus effect of energy investments is comparatively low. Conclusion The study empirically estimates the economic contribution of energy sector in Guangdong and based on the findings, suggests recommendations for high-quality development of Guangdong's energy sector. These can serve as references for the development planning and policy-making of Guangdong's energy development.
Accepted Manuscript
, Available online ,
doi: 10.16516/j.ceec.2023-294
Abstract:
Introduction Gas-steam combined cycle units have been widely used in combined heat and power, but their minimum power generation is limited by heat supply. Especially during the winter heating period in the north, gas-steam combined cycle units cannot reduce their output, thus impeding the grid integration of wind energy and causing wind curtailment. Method To address this issue, this paper investigates whether utilizing the operational flexibility of gas-steam combined cycle units in combined heat and power dispatch can promote wind power accommodation. To this end, a mathematical model was established to describe the diversified operating modes of gas-steam combined cycle units, then an economic dispatch model for combined heat and power considering wind power accommodation was constructed to co-optimize the unit commitment of coal-fired units, the operating modes of gas-steam combined cycle units, and the output distribution and reserve sharing among units. Result Case simulations revealed that during difficult periods of wind power accommodation, switching gas-steam combined cycle units from the two-on-one mode to one-on-one mode can reduce the wind curtailment rate by 1.28%, and switching them from extraction condensing to back pressure mode can reduce the wind curtailment rate by 4.55%. Conclusion Case analysis shows that making full use of the mode switching ability of gas-steam combined cycle units in combined heat and power dispatch can reduce the output of units during periods of high heat load, increase the wind power accommodation space to reduce the wind curtailment, increase the output ranges of units during periods of low heat load, thereby providing spinning reserve for the system and optimizing the reserve sharing among units.
Strategies for Improving the Safety and Operational Reliability of High-Voltage Frequency Converters
Accepted Manuscript
, Available online ,
doi: 10.16516/j.ceec.2023-184
Abstract:
Introduction "Energy saving and emission reduction" is the national technical requirement for industrial projects in recent years, and the frequency conversion technology can make process equipment adjust output under different working conditions, thereby saving resources. However, frequency converters are power electronic devices, and the failure rate of IGBT components is relatively high, and the requirements for the operating environment are harsh. Therefore, it is very important to improve the safety and operational reliability of high-voltage frequency converters. Method In the case of failure of individual power units of the high-voltage frequency converter, according to the neutral point drift technology, the position of the neutral point and the angle between the three-phase voltages are adjusted, so that the high-voltage frequency converter can bypass some faulty power units can still operate normally; Send the real-time status of the high-voltage inverter to the DCS, and realize the automatic bypass technology of the high-voltage inverter according to the logic configuration of the DCS; Set up a separate high-voltage inverter room to provide a relatively good operating environment for high-voltage inverters through air conditioning, ventilation, and air duct systems. Result After adopting the internal strategy and external environment strategy for the high-voltage inverter, the failure rate of the high-voltage inverter is reduced, and the safe operation time of the high-voltage inverter is prolonged. Conclusion The use of neutral point drift technology and the automatic bypass technology of the whole machine can reduce the failure probability and frequency of high-voltage inverters, and jointly improve the temperature and humidity conditions of the operating environment, which can increase the continuous and reliable operation time of the inverter, to greatly improve the safety and operation reliability of inverters.
Display Method:
2025, 12(2)
Abstract:
2025, 12(2): 1-14
doi: 10.16516/j.ceec.2024-334
Abstract:
Objective The implementation of carbon neutrality and carbon peaking policies has promoted the rapid development of wind power, a clean energy source. In recent years, extreme weather and climate events occur frequently, and with the large-scale production and grid connection of wind power, the issue of meteorological disasters in wind farms caused by extreme weather has become more prominent. Extreme weather not only poses severe challenges to wind power development, but may also affect the grid stability and reliability of power supply. Therefore, it is necessary to deeply understand the mechanism of how extreme weather affects wind power development, and take effective prevention and response measures to ensure the healthy and safe development of the wind power industry. Method By reviewing the recently published literature on meteorological disasters in wind farms, the paper classified the high-impact weather affecting wind power development into two major categories: extreme weather and adverse weather. It summarized the impacts of extreme weather such as typhoon, strong wind, lightning, rainstorm, sandstorm, cryogenic freezing and high temperature, as well as adverse weather such as calm breeze wind, salt spray and sea fog, on wind farm planning, resource assessment, survey and design, installation construction, infrastructure, wind power output and wind power prediction during the planning and design, construction and operation stage of wind farm. Result In the planning and design stage, it is necessary to identify and assess the risks of extreme weather, and carry out scientific macro and micro site selection. In the construction stage, rainstorm, cryogenic freezing and so on can affect transportation and delay the construction period; strong winds, heavy rain and so on affect hoisting and cause operational risks; sea fog, lightning and so on may affect the safety of offshore wind power construction. In the production and operation stage, extreme weather can lead to large-scale shutdown of wind farms and loss of output, and even threaten the safe and stable operation of the power grid. Except for tropical cyclones of a certain intensity, other high-impact weather events are not conducive to wind power output. The frequent occurrence of extreme weather leads to a reduction in the accuracy of wind power forecasting. Conclusion Finally, measures to cope with high-impact weather are proposed, including strengthening emergency management and extreme weather monitoring and early warning, considering the impact of extreme weather on wind power forecasting, and strengthening the construction of energy storage system.
2025, 12(2): 15-25
doi: 10.16516/j.ceec.2024-301
Abstract:
Objective With the large-scale development and utilization of wind and solar energy resources, the impact of the construction and operation of wind farms and photovoltaic power plants on local climate has received widespread attention. The paper focuses on summarizing the research progress on the impact of wind farms and photovoltaic power plants on local climate, providing support for their scientific and reasonable planning and layout, as well as the sustainable development of wind and solar energy. Method The paper reviewed existing research results in this field and summarized the research methods, impact mechanisms, research processes and achievements on local climate effects of wind farms and photovoltaic power plants. Result Wind turbines operation causes local climate change as a momentum sink and turbulence source, which reduces the wind speed in the downwind direction on the one hand, and affects the exchange of energy and matter between land and air by changing the turbulent motion of the boundary layer on the other hand. Furthermore, the momentum, wind speed, sensible and latent heat fluxes in the near surface layer are changed directly and precipitation and cloud cover are changed indirectly. The construction of photovoltaic power plants has significantly changed the characteristics of the land surface and led to changes in the energy budget and distribution between land and air, the environmental temperature cooling effect and the heating effect exist simultaneously, which in turn produces feedback on the local climate system. The environmental temperature cooling effect is caused by physical obstruction, surface evaporation reducing and conversion of radiation energy into electrical energy. The heating effect is caused by the heat release of photovoltaic modules during the photoelectric conversion process and the weakening of nighttime radiation cooling on the surface. The integrated operation of wind and photovoltaic power may form a positive feedback mechanism of increased surface roughness/reduced albedo - increased precipitation - increased vegetation, leads to increased local climate change. Conclusion In the context of building a new power system with new energy as the main body, the construction of large-scale wind and photovoltaic bases with a focus on deserts, gobi and wasteland areas has become a top priority for the development of new energy in the 14th Five-Year Plan period. The research on its impact on the climate and environment needs to be continuously carried out.
2025, 12(2): 26-35
doi: 10.16516/j.ceec.2024-358
Abstract:
Objective The analysis of limited icing capacity of wind turbine in cold wave weather is difficult to predict, resulting in inaccurate wind power prediction and insufficient decision-making basis for wind power dispatching. Method Through the prediction model of the limited icing capacity of wind turbine, the limited icing capacity of wind turbine in extreme cold wave weather process in Guangxi was analyzed and summarized by using conventional meteorological observation data, wind turbine shutdown actual data and numerical model data. Result The results show that the reference value and accuracy of icing prediction are effectively improved by integrating the numerical prediction products with the actual data of limited icing capacity and applying regression analysis for real-time correction. In addition, the icing prediction model can effectively respond to the strong cold air system southward affecting the Guangxi wind farm, but the response to the turning weather is insufficient, and the prediction result is larger than the actual data. At the same time, the numerical model prediction results have amplitude deviation and phase deviation, and the predicted value is larger than the actual value in this process. In terms of prediction effect, the model performs better in air temperature prediction than relative humidity and wind speed prediction, and the prediction effect of meteorological elements in high altitude areas is generally better than that in low altitude areas. Conclusion Based on the above conclusions, some suggestions are put forward, such as strengthening the early warning and prediction ability of cold wave, carrying out the upgrading and transformation of icing capacity prediction system, so as to improve the prediction accuracy of the limited icing capacity of wind turbine in extreme cold wave weather.
2025, 12(2): 36-47
doi: 10.16516/j.ceec.2024-182
Abstract:
Objective The purpose is to reveal the ways, extents and differences in how electricity consumption across various regions in China is influenced by temperature changes. Method Data on monthly total social electricity consumption and corresponding average temperatures for 29 provinces municipalities and autonomous regions from 2008 to 2020 were collected. Monthly meteorological electricity consumption and relative meteorological electricity consumption were calculated for each province, along with trend coefficients and correlation coefficients with concurrent temperatures. National distribution maps of these parameters were drawn, and their spatial differences and possible causes were analyzed. Result The results show that: (1) With rising summer temperatures, meteorological electricity consumption shows an increasing trend, especially significant in the eastern regions, Chongqing, and Shaanxi, while it is not significant in western and northern regions (such as Xinjiang, Qinghai, Gansu and Heilongjiang). The trend coefficients of relative meteorological electricity consumption also vary significantly among regions with a significant relationship, with an average trend coefficient of 1.5%/℃ in the three northeastern provinces, reaching 5%/℃ in Central China and Eastern China (excluding Fujian), and about 3%/℃ in Guangxi, Chongqing and Shaanxi. (2) Winter temperature changes also have a certain relationship with electricity consumption in various regions of China. When winter temperatures decrease, electricity consumption shows an increasing trend, and a significant relationship is observed in most areas of China, except for the southern coastal regions and Guizhou, with an extremely significant relationship extending from the northeast and north China to the southwest region. The trend coefficients of relative meteorological electricity consumption range from −2.0%/℃ to −7.5%/℃. (3) Spatial correlation analysis shows that summer meteorological electricity consumption and the trend coefficients of relative meteorological electricity consumption are significantly positively correlated with temperature. For each 1℃ increase in temperature, both meteorological electricity consumption and relative meteorological electricity consumption show a significant increase, while in winter, the correlation is weakly negative. Conclusion These results have important reference value for energy demand forecasting, energy supply assurance, addressing climate change, achieving the carbon peaking and carbon neutrality goals.
Wind-Induced Vibration Response and Weak Locations of 110 kV Diverging Branch Rods Under Strong Wind
2025, 12(2): 48-57
doi: 10.16516/j.ceec.2024-328
Abstract:
Objective The cross arms of the diverging branch rods are arranged perpendicularly, with cross-sectional dimensions varying linearly with height. Due to the complexity of structural modeling, corresponding structural analysis has not yet been conducted. Method To analyze the wind-induced vibration response and weak locations of diverging branch rods under strong wind conditions, a shell element finite element model was established to obtain its true mode shapes and a simplified beam element finite element model was proposed. Non-structural components were also addressed. The validity of the simplified model is verified by comparing mode shapes and frequencies. Dynamic response analysis under wind attack angles of 90°, 60°, 45°, and 0° were conducted to study the wind-induced vibration response and identify weak locations at various angles. Result The study shows that the mode shapes of diverging branch rods are primarily characterized by bending deformation, with negligible influence from torsion. Under a 90° wind reaction angle, the maximum wind-induced displacement at the top of the tower exceeds the relevant specified limits, and the stress at the base of the tower is the highest. Under a 45° wind reaction angle, the displacement at the top of the tower is the smallest, but the stress at the base is second only to that under a 90° wind reaction angle. The 90° wind reaction angle represents the most adverse condition. Conclusion The design control parameter for diverging branch rods is the displacement at the top of the tower. Additionally, the stress at the base of the tower is significant and poses a risk. Under different wind attack angles at a design wind speed of 29 m/s, the stability of the diverging branch rods meets the requirements, but the displacement at the top of the tower exceeds the limits. Existing diverging branch rods should be reinforced, while planned constructions can consider reducing span length or increasing cross-sectional area to avoid displacement exceeding limits.
2025, 12(2): 58-70
doi: 10.16516/j.ceec.2024-276
Abstract:
Objective The renovation and upgrading of old wind farms through "replacing small with large", fully tapping into the value of existing wind and land resources, and improving the efficiency of existing wind farms, is an important guarantee for promoting the development of new energy and achieving the "3060" carbon peaking and carbon neutrality goals. Method This article provided an overview of the current status of wind farm renovation and upgrading, investigated the policy situation, conducted research and analysis on typical renovation and upgrading projects, and summarized the experience and existing problems of current progress. Result The national policies for the renovation and upgrading of old wind farms are clear, local policies are gradually being implemented, and the external environment is improving. The advanced experience of successfully renovated old wind farms includes actively communicating with regulatory authorities, fully benefiting from policy dividends, fully utilizing old wind farm equipment, effectively reducing construction costs, developing technical solutions tailored to local conditions, and achieving cost reduction. However, large-scale renovation and upgrading still face significant problems such as prominent new energy consumption issues, difficulty in capacity expansion and renovation, increased uncertainty in electricity prices, and incomplete asset recovery paths. Conclusion To further enhance the efficiency of the renovation and upgrading of old wind farms, the industry still need to focus on the applicability of policy to the boundary conditions of renovation projects, selection of wind turbines, optimal layout of wind farms, consideration of environmental benefits of renovation of old wind farms and selection of reasonable financial evaluation methods, among other key directions, to promote the healthy, green and efficient the renovation and upgrading of old wind farms.
2025, 12(2): 71-78
doi: 10.16516/j.ceec.2023-235
Abstract:
Objective Wrinkle is a kind of defect that may occur in the manufacturing process of wind turbine blades. It may cause the strength of the blade to decrease, and in serious cases, cracks will be produced and lead to blade fracture, how to repair the wrinkle defects and verify the structural safety of the blade after repair is the focus of this paper. Method The blade of a megawatt-class unit of wind farm with spar cap wrinkling damage was selected as the research object. Firstly, the blade three-dimensional structural model and finite element model were established, and the blade buckling stability and the permissible number of spar cap were analyzed through finite element simulation; then, the wrinkle height was predicted through the strength loss ratio of glass fiber reinforced plastic (FRP), and a repair scheme was formulated; finally, the reliability of the repair scheme was verified through the full-size static and fatigue tests of the blade. Reslut The results show that the spar cap would not have buckling instability and fatigue failure if there is no wrinkling defect; the repaired blade passed the static and fatigue tests. Conclusion The repair scheme formulated based on the FRP strength loss ratio has a certain degree of reliability and provides a reference for the repair of wind turbine blade spar cap wrinkle.
2025, 12(2): 79-96
doi: 10.16516/j.ceec.2024-311
Abstract:
Objective The paper takes the NREL-5MW wind turbine as the research object, adopts the control strategy based on the single and combination of the yaw angle(θ) of the upstream wind turbine and the tower height(ΔH) difference of the downstream wind turbine as well as the lateral spacing(Δy), researches the complex wake interference effect between the two wind turbines. Method Numerically simulated the part of the wake interfering phenomenon between the two wind turbines, analyzed the aerodynamic power of the two wind turbines, the average speed of the wake flow, and the effect of the wake interference to improve the power generation of the whole wind power field efficiency of the whole wind farm. Result The results show that the overall power of the wind turbine and its enhancement ratio are maximized when the combined strategy is implemented, especially when adjusting the lateral spacing Δy=4D or Δy=8D on the basis of θ=20°. Conclusion By changing the yaw angle of the upstream wind turbine or the upstream and downstream wind turbines staggered arrangement and other wake effect inhibition strategies, the power output of the upstream wind turbine is reduced and the effect of the wake of the upstream wind turbine is improved, which can improve the aerodynamic power output of the downstream wind turbine and the overall power generation of the wind turbine, and improve the power generation efficiency of the wind turbine in a relatively large scale, and provide a certain degree of numerical simulation for the optimization of the arrangement of large-scale wind farms support.
2025, 12(2): 97-103
doi: 10.16516/j.ceec.2024-022
Abstract:
Objective In order to solve the problem of difficult operation and maintenance of offshore wind farms, the intelligent maintenance and repair platform is proposed. Method The platform was created by applying intelligent inspection (pressure station patrol robot, drone patrol), automatic intelligent maintenance (wind bolt fastening robot, wind turbine anti-corrosion spraying robot, maintenance decision-making), operation supervision (intelligent access control, visual helmet), intelligent operation and maintenance scheduling and training services. Result The problem can be solved with the shortage of offshore wind farm operation and maintenance resources, backward offshore wind power operation and maintenance technology, poor accessibility of offshore wind farms, high cost of offshore wind power operation and maintenance, lack of standards and specifications in the offshore wind power operation and maintenance industry, lack of professionals and other related operation and maintenance pain points. Taking the inspection of the main transformer at the offshore station and the anti-corrosion coating of wind turbines as examples, the two aspects are analyzed , including the intelligent inspection and maintenance decision table of the offshore station robot, as well as the specific scheme analysis of the anti-corrosion and rust removal robot for wind turbines. Conclusion Therefore, it can improve the intelligent level of operation and maintenance of offshore wind farms, reduce operation and maintenance costs, reduce costs and increases efficiency, and is expected to be applied and promoted in engineering.
2025, 12(2): 104-115
doi: 10.16516/j.ceec.2024-177
Abstract:
Objective The heavy-duty truck swapping station addresses challenges such as long charging times and limited driving range in electric heavy-duty trucks, the power battery faces issues of large capacity, high frequency of use, and a heightened risk of thermal runaway. Method To solve the above problems, a coupled bidirectional charging machine's battery thermal-electric coupling model was established to investigate the thermal characteristics of the electric heavy-duty truck's power battery, and the COMSOL-SIMULINK was used for joint simulation. Result The results indicate that the proposed coupling model can effectively control the voltage and current of the battery under V2G operating conditions. In the early stages of the V2G condition, the maximum current density is at the junction of the positive electrode and the positive electrode tab. The temperature of the positive electrode tab is significantly higher than the cell temperature, with a temperature difference of 4.1 ℃.In the later stages of the V2G condition, the maximum local current density shifts from the electrode tab towards the bottom of the battery. The bottom region, influenced by concentration, favors electrochemical reactions, the cell temperature is higher than the electrode tab temperature. Under abusive thermal conditions, the sequence of secondary reactions includes the decomposition of the SEI membrane, negative electrode decomposition, and positive electrode reaction with the electrolyte.Among these reactions, the heat generated by electrode secondary reactions is the main cause leading the battery into irreversible thermal runaway. The decomposition reaction of the SEI membrane is an indicative sign of the initiation of thermal runaway in the battery. Conclusion The proposed external circuit thermoelectric coupling model can reflect the temperature distribution and thermal runaway effects of the battery thermoelectric coupling model under the excitation of the bidirectional charger in the heavy-duty truck exchange station.
2025, 12(2): 116-127
doi: 10.16516/j.ceec.2024-271
Abstract:
Objective With the rapid increase in the number of electric vehicles (EVs), the impact of EV energy storage on the power grid has become increasingly significant. To enable dynamic interaction between EV charging stations and the grid, and to use EV energy storage to regulate load in order to reduce peak-valley differences and mitigate grid impacts, this paper proposes a control and scheduling strategy based on virtual synchronous technology, considering the integration of reactive power response into the new power system. Method Firstly, a day-ahead application mechanism was adopted, and a two-layer rolling optimization scheduling model was established to formulate charging plans for each charging station. Then, considering the working mode and characteristics of the V2G (Vehicle to Grid) system, an improved virtual synchronous control method was proposed. Under this control method, power can flow bidirectionally, and optimal power distribution was achieved through the V2G scheduling control strategy, thereby realizing both active and reactive power dispatch responses. Result Experimental results show that the proposed strategy effectively reduces the impact of EV charging and discharging on the power system, enhancing system stability. Additionally, by issuing upper-level scheduling instructions to the lower-level V2G converter controls, bidirectional interaction between charging stations and the grid can be well realized. Conclusion The combination of the upper-level scheduling strategy and lower-level converter control strategy not only meets the basic needs of the V2G system but also demonstrates excellent output characteristics. This control and scheduling strategy provides strong support for the stable operation of future power systems.
2025, 12(2): 128-133
doi: 10.16516/j.ceec.2024-204
Abstract:
Objective During the operation and storage of lithium batteries, substantial heat is generated. Anomalies in temperature can impact the lifespan and cycling efficiency of lithium batteries, and in extreme cases, may lead to explosions. Therefore, research on thermal runaway warning for lithium batteries is crucial for ensuring their operational safety. Method The DTW-Kmeans algorithm was employed to identify anomalies in the temperature rise rate of lithium batteries. Subsequently, the physical characteristic of surface temperature decrease following the opening of the lithium battery safety valve was incorporated. A dual-feature fusion approach was utilized to propose a thermal runaway warning mechanism for lithium batteries. Result Repetitive experiments have validated the effectiveness of the proposed early warning algorithm in distinguishing abnormal lithium batteries based on temperature rise rates. Furthermore, it is capable of identifying the sudden change in temperature rise rates from positive to negative in abnormal lithium batteries, achieving a comprehensive recognition accuracy rate exceeding 90%. Conclusion The early warning algorithm is able to accurately identify lithium batteries with abnormal temperature rise rates, and can promptly and precisely detect the timing and location of the opening of the safety valve in the lithium battery. Consequently, this early warning algorithm serves as a preemptive measure against thermal runaway in lithium batteries, thereby safeguarding the safe operation of lithium-ion battery packs.
2025, 12(2): 134-144
doi: 10.16516/j.ceec.2024-179
Abstract:
Objective With the depletion of fossil fuels and bio-fuels' emergence, ethanol-hydrogen hybrid fuel as a new generation of renewable clean fuel has attracted wide attention, so it is necessary to study the effect of ethanol-hydrogen premixed flame combustion characteristics. Method Based on the constant volume combustion system and combined with high-speed schlieren technology, the effects of the equivalent ratio and pressure on the laminar combustion characteristics of ethanol-hydrogen premixed flame were studied under the conditions of initial temperature of 370 K, hydrogen ratio of 50%, equivalent ratio of 0.7~1.4 and initial pressure of 1, 2 and 4 bar. Focusing on the propagation combustion characteristics of the flame, the laminar combustion velocity was calculated and its influencing factors were analyzed. The relevant reaction model was established with the help of Chemkin simulation platform, and the chemical dynamics of the laminar combustion characteristics were analyzed in detail by using Marinov's ethanol oxidation reaction mechanism. Result The results showed that the laminar combustion velocity was positively correlated with the adiabatic flame temperature and reached the maximum value around φ=1.1. The pressure significantly affects the net heat release rate, and the peak value occurs in the higher temperature region with a greater equivalent ratio. R1:H+O2⇔O+OH represents the most sensitive reaction which promotes the laminar combustion velocity of the flame. With the increase of pressure, the peak molar fraction of H, OH, and O free radicals gradually decreased and moved upstream. With the increase of the equivalent ratio, the molar fraction of H and O free radicals gradually decreased, and the molar fraction of OH free radicals first increased and then decreased. Conclusion The equivalent ratio, pressure and active free radicals have significant effects on the laminar combustion characteristics of ethanol-hydrogen premixed fuel, which can provide theoretical basis for subsequent studies.
2025, 12(2): 145-157
doi: 10.16516/j.ceec.2024-173
Abstract:
Objective Small-scale compressed air energy storage systems are independent of specific geographic environments, have broad applicability, low construction and operating costs, and are suitable for distributed energy systems and microgrid applications. They offer continuous, stable power security for remote areas, islands, or temporary facilities. To enhance the efficiency of a small-scale compressed air energy storage system, the article analyzes the impact of operating the system under various conditions on its performance. Method A static model and a dynamic model of a small advanced compressed air energy storage system were established. Taking the 10 kW class energy storage system as a case study, the impact of compressor inlet temperature, compressor total pressure ratio, and the number of expansion stages on the thermal performance of the system was analyzed. Additionally, the dynamic variations in temperature and pressure of the storage tank were simulated based on Matlab simulation software. Result The results indicate that although higher compressor inlet temperature and overall pressure ratio reduce the energy storage efficiency of the system, they increase the energy storage density. The post-throttling pressure (inlet pressure of the expansion section) affects the energy storage density. Under design conditions, when the post-throttling pressure is 1.35 MPa, the energy storage density reaches a maximum value of 8.15 MJ/m3. When the energy storage pressure increases from 3 MPa to 6 MPa, the system's energy storage efficiency increases by 9.02%, and the energy storage density grows by 1.72 times. With increased heat exchange between the gas storage tank and the environment, the energy storage efficiency initially decreases and then increases. When the heat transfer coefficient is 5 W/m2/K, the system's energy storage efficiency reaches a minimum value of 45.98%. Conclusion For small adiabatic compressed air energy storage systems, increasing the storage pressure of the tanks and improving the heat exchange between the tanks and the environment can effectively enhance the energy storage density of the system. These findings offer valuable insights for the design and optimization of such systems.
2025, 12(2): 158-168
doi: 10.16516/j.ceec.2024-281
Abstract:
Objective At present, the application of wireless power transmission technology on Unmanned Aerial Vehicle (UAV) is becoming a research hotspot, but the endurance of UAV remains one of the main bottlenecks in development. Method This paper proposed a wireless power transmission system with strong coupling capability and capable of realizing constant voltage output for small and medium-sized UAV. Compared with the current mainstream multi-rotor UAV wireless charging system, this design scheme utilized the underdamped resonance principle to realize high-frequency inversion through a single transistor, which replaced the full-bridge and half-bridge inverter with a more miniaturized and lightweight one. And it avoided the bridge arm direct conduction problem and improved the stability of the circuit. Meanwhile, the LCC-S/CLC compensation topology realized the constant current/constant voltage output based on the magnetic coupling resonant wireless power transmission system. The design of the magnetic coupler not only enhanced the coupling capability between the receiving side and the transmitting side of the coupling coil, but also reduced the number of turns of the coil on the receiving side, meeting the lightweight requirements of UAVs. Result Finally, a simulated UAV charging experimental platform with a rated power of 100 W is built with 25 V input, and the peak efficiency can reach 92%. Conclusion The simulation and experimental results verify the theoretical analysis and calculation and prove the feasibility of the wireless power transmission system based on a single-transistor inverter.
2025, 12(2): 169-180
doi: 10.16516/j.ceec.2024-260
Abstract:
Objective With the steady advancement of nationwide electricity market reforms, regions like Guangdong and Shanxi have entered the formal operation phase of electricity spot markets. The frequent and unpredictable price fluctuation in the electricity spot market has significantly impacts or the annual revenue of power generation enterprises. This paper aims to deeply analyze the actual value of medium-and long-term contracts, provide scientific and reasonable pricing basis for electricity trading in these contracts, and thus reduce the market risks for power generation enterprises (especially new energy power generation enterprises) signing medium-and long-term contracts, while increasing their power generation income. Method This paper selected the Guangdong electricity spot market as a case study, thoroughly analyzing the current stage's congestion cost allocation mechanism and the settlement method of congestion costs in medium-and long-term contracts. Based on historical data, the paper conducted a value evaluation analysis of medium-and long-term contracts implementing separate settlement of medium-and long-term congestion costs. Additionally, for new energy power generation units with base electricity, the paper quantitatively analyzed the actual value of medium-and long-term contracts under current base electricity conditions, providing a basis and suggestions for the pricing of medium-and long-term contracts. Result Under the framework of separate settlement of medium-and long-term congestion costs, the value of medium-and long-term contracts for conventional power generation units mainly depends on the day-ahead unified settlement point price. For new energy power generation units, due to the influence of base electricity and other factors, the value of medium-and long-term contracts is also closely related to the node price and the output characteristics of the new energy. Conclusion The paper summarizes the value formulas for medium-and long-term contracts applicable to both conventional and new energy power generation units under the separate settlement of medium-and long-term congestion costs, and based on this, proposes pricing suggestions for medium-and long-term contracts. Providing clear valuation and pricing strategies for medium-and long-term contracts for the power generation side, particularly for new energy power generation units, this paper also offers crucial guidance for rule-makers in improving congestion management mechanisms.
2025, 12(2): 181-194
doi: 10.16516/j.ceec.2024-401
Abstract:
Objective Under the "dual carbon" goals, the trading of environmental interest products, as an environmental management measure based on the market mechanism, is crucial for promoting sustainable development. However, the concepts of domestic electricity-carbon environmental interest products have not been standardized and unified, and their related theories, policies and market mechanism designs also need to be improved. Therefore, this article conducts a comprehensive review and analysis on the development status, value verification, and existing problems of typical environmental interest products, and puts forward relevant suggestions for improving China's environmental interest product trading system. Method First, focusing on typical environmental interest products such as green certificates, green electricity, carbon quota, and Chinese Certified Emission Reduction (CCER), the development status of the markets where these interest products are located, and sort out their policy evolutions, market scales and other situations. Second, conduct a comparative analysis of the ways to define the environmental value of new energy at home and abroad, summarize the four ways of verifying the value of China's current environmental interest products, and then put forward the design of the coupling mechanism for the future electricity, carbon and certificate markets. Finally, deeply discuss the key problems faced by the trading of environmental interest products, including decentralized product management, low environmental premium, and low international recognition. Result Presenting targeted suggestions for the above problems, such as promoting the construction of the electricity-carbon-certificate market linkage mechanism, standardizing the environmental value definition standards, and improving the international recognition of green certificates. Conclusion This article reviews the development status and trading mechanisms of typical environmental interest product markets, uncovers a series of problems currently faced by the markets, and needs to put forward policy suggestions from aspects such as market mechanisms, product values, and the international environment, so as to improve China's environmental interest product trading system, thereby enhancing the efficiency of environmental resource allocation, and finally helping the economy and the environment achieve a good situation of coordinated development.
