Current Articles

2024, Volume 11,  Issue 4

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Cover & Contents
2024, 11(4)
Abstract:
Energy Internet of Things in the Perspective of Internet of Everything: Current Status, Technologies and Case Analysis
SONG Hang, WEN Xiang, ZHAI Hua
2024, 11(4): 1-15. doi: 10.16516/j.ceec.2024.4.01
Abstract:
  Introduction  The new generation of the Internet of Things (IoT) is being fostered in the era of Internet of Everything (IoE), realizing its diverse development by selecting and combining new information, functions, and applications. The Energy Internet of Things (Energy IoT) which is based on IoT, envisions a future where physical things are connected through a dynamic network that exchanges information and energy. The Energy IoT is giving rise to new service models and methods for organizing, exchanging, and managing energy; It covers not only new concepts such as Energy-as-a-Service and Prosumer, but also leads to innovative applications in smart buildings, intelligent metering, smart grids, distributed energy, virtual power plants and more.   Method  This paper analyzed the current status of the Energy IoT, including its key industry drivers, potential technologies and applications, challenges and related research areas.   Result  This paper discusses and compares the definitions of Energy Internet and Energy IoT from academic and industry perspectives. And it analyzes some major stages and issues of future research in the Energy IoT.   Conclusion  This paper provides a useful reference for further research and practical applications in the field of Energy IoT.
Microchannel Reactor for Hydrocarbon Fuel Synthesis from CO2 Catalytic Hydrogenation
LUO Pan, TAN Wenjie, HU Enxiang, YANG Yingju, HUA Zhixuan, LIU Jing
2024, 11(4): 16-22. doi: 10.16516/j.ceec.2024.4.02
Abstract:
  Introduction  CO2 catalytic hydrogenation for fuel synthesis is an economically feasible and large-scale implementable technology for CO2 utilization, which can solve the problems of environment and resource shortage, and has gained wide attention in recent years. In this work, a microchannel reactor for CO2 catalytic hydrogenation to synthesize hydrocarbon fuels is developed.   Method  Based on the design concept of thermodynamic calculation, catalyst preparation, reactor design, structure optimization and performance testing, an anlysis was carried out.   Result  The thermodynamic analysis shows that hydrocarbon fuels can be produced from CO2 catalytic hydrogenation. Six iron-based catalysts are developed to improve the reaction rate of hydrocarbon fuel synthesis. Based on the computational fluid dynamics (CFD) simulation, the structure of the microchannel reactor is designed and optimized. The microchannel reactor has the advantages of simple-compact structure and strong heat-mass transfer capability. The experimental results show that the Zn-Fe catalyst exhibits the best performance of CO2 catalytic hydrogenation for the synthesis of low-carbon olefins. CO2 conversion and low-carbon olefins selectivity are 32% and 44% respectively.   Conclusion  The microchannel reactor designed in this work has the dual functions of CO2 utilization for hydrocarbon fuel synthesis, which is of great significance to China's response to climate change, the realization of the dual-carbon target and the development of hydrocarbon fuel industry.
Application of Wide Spectrum Conjugated Small Molecule for High Efficiency Solar-Powered Seawater Desalination and Power Generation
ZHU Jingshuai, QIU Xiaopan
2024, 11(4): 23-30. doi: 10.16516/j.ceec.2024.4.03
Abstract:
  Introduction  In order to solve the problems of high cost and complex preparation process of solar desalination devices, organic small molecule photothermal materials, which possess advantages such as light weight, low cost, simplified synthesis and purification processes, are selected as solar energy absorption materials.   Method  A kind of organic conjugated small molecule Y6 was combined with a low-cost cellulose paper to prepare a Janus structure water evaporator with wide spectrum absorption in the range of 350~1 000 nm and high photothermal conversion performance.   Result  The bottom surface of the evaporator has efficient water adhesion, facilitating rapid water collection, while the top surface has water repellency, which can achieve the self-floating ability. Moreover, each 3.14 cm2 device only needs 0.5 mg photothermal material to achieve a temperature of more than 70 ℃, demonstrating significant material-saving advantages.   Conclusion  Under 1.0 kW/m2 solar irradiation, the photothermal conversion efficiency of Y6-based evaporator is 64.4%, and the evaporation rate is up to 1.13 kg/(m2·h), which is obviously higher than that of the control cellulose paper evaporator. After solar evaporation desalination, the purified water obtained exhibits a significant reduction in ion concentration by 4~6 orders of magnitude compared to the initial simulated seawater. When the evaporator is integrated with a thermoelectric device, the evaporation rate reaches 1.02 kg/(m2·h) under 1.0 kW/m2 solar irradiation. Meanwhile, an output voltage of 55 mV is generated. This study demonstrates that the solar evaporator based on organic small molecule Y6 has a promising application prospect in the synergistic effect of photothermal water purification and thermoelectric power generation.
Development Application and Dynamic Characteristics of Synchronous Condenser in Electric Power System
ZHANG Dongqing, ZHANG Guohua, XU Lingling, GAO Shengfu
2024, 11(4): 31-41. doi: 10.16516/j.ceec.2024.4.04
Abstract:
  Introduction  With the establishment of the energy Internet architecture mainly relying on new energies, HVDC transmission has become an important way of power transmission, power grids present a new characteristic of "strong DC and weak AC". Synchronous condensers have unique advantages in dealing with the issue of "strong DC and weak AC" by virtue of their dynamic performance such as fast reactive power response and strong voltage support capability.   Method  To study the application of synchronous condensers in HVDC works, this paper summarized the development of synchronous condensers, introduced the current development status of several major types of synchronous condensers in China, such as synchronous condensers for transforming thermal power units, new-generation large-capacity synchronous condensers, distributed synchronous condensers, analyzed the working principle and dynamic characteristics of synchronous condensers. Then the paper summarized the virtues of synchronous condensers when compared with other reactive power compensation devices such as SVC, the application scenarios, existing configuration strategies of large-capacity synchronous condensers and distributed synchronous condensers.   Result  Finally, a simulation model of DC transmission system with synchronous condensers is built on the PSCAD/EMTDC platform. The simulation verify the suppression capability of synchronous condensers for commutation failure at the sending end and transient overvoltage at the receiving end caused by commutation failure, as well as the dynamic reactive power compensation capability under lagging phase operation.   Conclusion  The analysis shows that synchronous condensers have adequate suppression of transient overvoltage and commutation failure and their reactive power response speed and dynamic reactive power support capability will not be affected by lagging phase operation, which contributes to their prospect of engineering application for steady-state compensation in converter stations.
A Review of Distributed Energy Storage System Solutions and Configurations for New Distribution Grids
HUANG Haiquan, HUANG Xiaowei, JIANG Wang, WANG Yuanyuan, WANG Yanfang, DING Hao, ZUO Jiewen, XIA Chenyang
2024, 11(4): 42-53. doi: 10.16516/j.ceec.2024.4.05
Abstract:
  Introduction  With the advancement of the "dual carbon" goals and the introduction of new energy allocation and storage policies in various regions, there is a need to further clarify the role of distributed energy storage in the new types of distribution networks and the configuration of associated energy storage system.   Method  This paper began by summarizing the configuration requirements of the distributed energy storage systems for the new distribution networks, and further considered the structure of distributed photovoltaic energy storage system according to different application needs. To maximize the economic aspect of configuring energy storage, in conjunction with the policy requirements for energy allocation and storage in various regions, the paper clarified the methods for configuring distributed energy storage systems and summarized the commonly used algorithms for determining the location and capacity. Based on this, research suggestions were proposed.   Result  Proper configuration of energy storage should be based on clear demands, selecting the appropriate topology and offering a configuration plan that is optimized by comprehensively considering indicators such as power supply stability, security, and economic efficiency of the distribution network.   Conclusion  Distributed energy storage technology is the key aspect of the new distribution networks and an essential means to ensure the safe and stable operation of distribution networks. To harness its full potential, further research into its optimal configuration and related control technologies is necessary.
Research Status and Prospect of Underground Artificial Rock Caverns for Compressed Air Energy Storage
YANG Xuewen, REN Hao, LIAO Zeqiu, WANG Jinxi, JIA Bin
2024, 11(4): 54-64. doi: 10.16516/j.ceec.2024.4.06
Abstract:
  Introduction  Compressed air energy storage (CAES) is a technology for storing electrical energy on a large scale, only second to pumped storage in terms of scale. The gas storage device is an important component of CAES. The gas storage facilities of compressed air energy storage power plants that have been put into commercial operation domestically and abroad are mostly natural geological structures such as salt caverns and abandoned mines. Large-scale, long-term compressed air energy storage requires more economical and widely applicable gas storage facilities.   Method  Artificial underground cavern gas storage facilities largely freed compressed air energy storage power plants from the reliance on specific geological conditions, becoming a strong support for the large-scale construction of long-term compressed air energy storage power plants. However, there were few research achievements in this field domestically and internationally. Understanding the research status at home and abroad, summarizing advanced experiences from other industries, and clarifying the challenges that need to be addressed urgently in this field had significant implications for the large-scale construction of compressed air energy storage power plants.   Result  There are significant differences in the operating characteristics between artificial underground caverns in compressed air energy storage power plants and conventional artificial caverns such as natural gas storage facilities and hydroelectric water conveyance tunnels, and there is a lack of mature design methods and regulations for this field, with many technological challenges still awaiting resolution. This paper reviews the characteristics and key research contents of underground artificial caverns in compressed air energy storage power plants.   Conclusion  Prioritizing safety, considering cost-effectiveness and fostering innovation provide a guarantee for the independent development of the underground hard rock gas storage facilities for compressed air energy storage power plants. This technology holds practical significance in enriching China's energy storage and power generation experiences, and improving new power systems. If this technology matures, it can provide strong support for the construction of a new power system in China.
Application Practice of 5G Customized Network Technology in Intelligent Management and Ecological Environment Monitoring of Offshore Wind Farm
TAN Renshen, QI Yongle, ZHOU Bing, FAN Yongchun, FENG Yiyang, PENG Jiajun, MAI Leixin
2024, 11(4): 65-75. doi: 10.16516/j.ceec.2024.4.07
Abstract:
  Introduction  In response to the inability of existing communication conditions to meet the intelligent O&M and ecological monitoring needs of offshore wind farm, this article explores and proposes a 5G customized network scheme to solve the problems of poor signal accessibility, incomplete network coverage, and low smoothness in offshore wind farms.   Methods  In this paper, a comprehensive O&M and monitoring scheme was proposed by using 5G customized network technology, which was as follows: through the deployment of 5G macro base stations outdoors, 5G indoor distribution in towers, and underwater laying of optical networks, the 3D coverage of wind farm communication networks was realized; Based on 5G slicing technology, one network could be used for multiple purposes to meet the needs of offshore wind farms for network differentiation; computing nodes were deployed in the centralized control center computer room, and private network data was forwarded through the edge UPF (user plane function) to achieve computing-network integration.   Result  The intelligent management and ecological environment monitoring scheme for offshore wind farms based on 5G technology proposed in this article has been piloted and tested based on the project. The test results show that the maximum effective coverage radius of 5G base stations reaches 11.3 km, and the stable transmission uplink rate reaches 5 Mbps, meeting the needs of observation data return and unmanned ship video return in the sea area. By deploying two 2.1G 8TR enhanced base stations on the booster station and wind turbine to enhance sea area coverage, the pull-net test around the wind farm verified that the 5G private network can effectively cover wind farms, with a coverage rate of 98.4%, which can basically meet the coverage needs of the entire wind farm.   Conclusion  This scheme utilizes a 5G private network to cover the sea area of the wind farm and achieves underwater communication through STN (Smart Transport Network) and underwater optical networks. Consequently, it innovatively constructs a 3D ocean monitoring and communication network, laying the communication foundation for the intelligent management and ecological environment monitoring of offshore wind farms.
Static Calculation on Integrated System of Offshore Wind Turbine Foundation and Aquaculture Cage
WANG Lihe, FU Fei
2024, 11(4): 76-87. doi: 10.16516/j.ceec.2024.4.08
Abstract:
  Introduction  With the continuous increase of offshore wind farms, conflicts in the use of marine areas has become increasingly severe. The integrated development of offshore wind power and aquaculture has attracted growing attention, with various structural designs for wind turbine foundations integrated with aquaculture cages being proposed. However, most of these designs are still in the conceptual stage and far from practical engineering applications.   Method  Based on the requirements of equal netting mass, equal biomass of marine growth attached to the netting, and equivalent hydrodynamic performance of the netting, the paper introduced an efficient method to calculate the equivalent loads of the cages. Considering the design loads of a 14 MW wind turbine and marine hydrological conditions, a jacket foundation structure suitable for the 14 MW offshore wind turbines was designed, integrating internal and external aquaculture cages to propose two integrated systems combining jacket foundations and marine aquaculture cages. Using the Morison model and considering the impact of nonlinear waves, static analyses of different designs were conducted in SACS based on the proposed equivalent modeling method for the cages.   Result  The study shows that the integration of internal and external cages with the jacket foundation has little to negligible impact on the first and second order frequencies of the overall system and a more significant effect on the third order frequency. The rotation condition is the controlling case, and after adding internal and external aquaculture cages, local reinforcement of the jacket foundation is required. Computational results for the integrated designs of the 14 MW offshore wind turbine jacket foundation with internal or external cages meet the regulatory design requirements.   Conclusion  The analysis results provide a reference for the engineering application of the integrated system design of offshore wind turbine foundations and marine aquaculture cage systems.
Design of Wireless Communication System for Offshore Converter Station
LIANG Zeyong, KUANG Jianrong, DANG Tong, CHEN Yi
2024, 11(4): 88-101. doi: 10.16516/j.ceec.2024.4.09
Abstract:
  Introduction  Aiming at the characteristics of offshore converter stations, the design scheme for wireless communication system of offshore converter station is proposed.   Method  By analyzing the characteristics and current application of offshore wireless communication technology and considering the requirements of equipment operation, station warning and personnel activities of offshore converter stations, the configuration scheme for the wireless communication system of offshore converter stations was proposed.   Result  Through the NAVTEX system, the requirement to receive weather and safety information is realized. Through the radar optoelectronic system and VHF ship to ship communication system, the requirement for vessel caution and expulsion is realized. Through UHF cluster intercom system, WiFi and mobile communication system, the daily communication requirement of personnel is realized. Through the lifeboat emergency communication system, microwave transmission system and satellite communication system, the requirement of personnel emergency avoidance is realized.   Conclusion  Therefore, the system can realize the basic communication requirements during the daily operation and maintenance of offshore converter stations, ensure the safety of equipment and personnel, and provide guidance for the design of wireless communication systems for offshore converter stations.
Analysis on Power Supply Structure Transformation Towards Carbon Neutrality in Guangdong
LUO Shasha, GUO Jingtao, CAI Yingqian, YU Xinmei
2024, 11(4): 102-110. doi: 10.16516/j.ceec.2024.4.10
Abstract:
  Introduction  In order to realize the goal of "dual-carbon", the green and low-carbon transformation of power supply side is the key to realize the green and low-carbon transformation of Guangdong, and at the same time, the construction of a diversified power supply support system with a high proportion of new energy is also the most important task for achieving a new type of power system in Guangdong. Therefore, it is of great significance to plan the carbon neutral power supply structure of Guangdong in advance.   Method  Based on the study of the prospective energy supply and demand pattern of Guangdong Province, this paper integrated the low-carbon transformation and energy security, considered the constraints from the proportion of non-fossil energy consumption, resource conditions, and the balance of power supply, and proposed a carbon-neutral power supply development idea for Guangdong, analyzed different transformation paths, and put forward relevant suggestions.   Result  The study shows that during the period of carbon neutrality, the total installed capacities of power supply in Guangdong Province is expected to reach about three times of the current installed capacities; the main body of power supply will be transformed from the current combination of "thermal power + nuclear power + external power supply" to "new energy + nuclear power + external power supply"; The proportion of non-fossil energy installed capacity will reach 80%, of which the proportion of new energy resources in the province will reach 50%.   Conclusion  The prospect of power structure adjustment in Guangdong Province seems optimistic. However, this process still faces many challenges from policy, technology and market, etc. It is suggested to pay attention to the role change of thermal power in the power system, safeguard the key factors of non-fossil energy development, and emphasize the building of regulating capacity for new power system; in order to meet the demand for electricity consumption in Guangdong twice as much as the status quo during the period of carbon neutrality, it is even more important to pay special attention to technological innovation issues leading the clean and low-carbon transformation of power supply structures, and through scientific and technological innovation, to promote the exploration of new energy types and new energy technologies towards the development of greater energy density and more efficient energy conversion.
Analysis on Green and Low Carbon Technologies for New Power System Substations
GU Jingda, BAI Xiaohui, LI Wei, WANG Yafeng, SONG Baotong
2024, 11(4): 111-117. doi: 10.16516/j.ceec.2024.4.11
Abstract:
  Introduction  Under the vision of carbon peak and carbon neutralization, the construction of the new power system substations is imperative.   Method  To promote the transformation of traditional substations to new power system substations, a full-lifecycle green and low-carbon construction scheme for new power system substations was proposed. Focusing on electrical equipment, building structures, building equipment and integrated energy, the carbon emissions throughout the entire life cycle of substations were reduced, and the new power system substations were constructed and operated in a green and low-carbon manner.   Result  The results show that compared with conventional substations, the proposed green and low-carbon construction scheme not only improves the development and utilization of renewable energy and accelerates the low-carbon upgrade of power grids, but also promotes energy saving and consumption reduction of power grid equipment, reduces carbon emissions and O&M costs of substations, and improves the utilization level of basic resources of substations, thus improving the comprehensive economic benefits of the substations.   Conclusion  The proposed green and low-carbon construction scheme has certain universality and replicability. It can provide theoretical and practical guidance for the transformation and transition of substations, and lay the foundation for the low-carbon development of the power grid.
Application of Pulsed Eddy Current Detection in Pipeline of Nuclear Power Plant
HAN Yang, ZHU Qi, CHEN Yongan, XU Ning
2024, 11(4): 118-126. doi: 10.16516/j.ceec.2024.4.12
Abstract:
  Introduction  In order to improve heat exchange efficiency, the condensate pipelines, main water supply pipelines drain pipelines and partial extraction pipelines of nuclear power plants are all coated outside the pipelines. At present, the test methods of ferromagnetic pipelines are mainly conventional ultrasound and ultrasonic guided waves. These test methods are limited by the detection environment and preconditions, which increase the difficulty of test. In order to improve the test efficiency of pipelines with insulation layer, we shall enrich technical methods, shorten maintenance period and improve economic benefit of nuclear power plant.   Method  This paper mainly studied the feasibility and reliability of pulsed eddy current testing method under low frequency electromagnetic interference in nuclear power plant, and used the measured and calculated values of the induced voltage to establish the optimal parameter inversion problem. In combination with the coupling relationship between the parameters and based on the time-domain analytical solution of the pipeline pulsed eddy current field, the paper established the specific relationship between the measured value and the calculated value of the induced voltage, and established the optimization parameter inversion problem. In combination with the coupling relationship between the parameters, the paper proposed a pulsed eddy current detection method for in-service operation and maintenance of insulated pipes in nuclear power plants.   Result  Using the pulsed eddy current detection method for the relative wall thickness of ferromagnetic pipelines proposed in this paper, in-service sample pipelines of nuclear power plant are tested and the testing result is compared with conventional ultrasonic testing. The error of the two testing results is about 5%.   Conclusion  The testing results of impulse eddy current testing are reliable and it is suitable for non-destructive testing and evaluation of nuclear power plant ferromagnetic pipeline wall thickness corrosion thinning.
Analysis on Electrocution Diagnosis Based on Discrete Wavelet Transform and GRU
CAI Gaofeng, WANG Qingbin, CHEN Zhenyu, XU Guipei, FENG Jiaqi, LUO Qichang
2024, 11(4): 127-136. doi: 10.16516/j.ceec.2024.4.13
Abstract:
  Introduction  In the low-voltage distribution network, the residual current protection device, as an important guarantee of electricity safety, can reduce the harm caused by the leakage fault of electrical appliances and prevent human electrocution accidents. The current residual current protection device relies on the residual current signal size as the basis for the action of the protection mechanism, but has no function to identify the electrocution characteristics. To address this problem, this paper proposes a method for electrocution signal feature extraction and electrocution diagnosis in low-voltage distribution networks based on wavelet decomposition and denoising, as well as GRU.   Method  In this paper, the residual currents collected from electrocution experiments were pre-processed by downsampling and discrete wavelet denoising; The time and frequency domain electrocution characteristic parameters of the residual currents were extracted by the sliding window method, and the Fourier transform was used to extract the characteristic parameters of residual currents to the second harmonic amplitude. All the extracted feature parameters were used to form a high-dimensional feature space vector; which was subject to dimensionality reduction using the method of principal component analysis to obtain a new set of three-dimensional feature vectors. A diagnostic model for electrocution was established, and the three-dimensional feature vectors representing electrocution features were input into the model. Comparison experiments were conducted on electrocution signals using five different electrocution diagnostic models, such as recurrent gated network (GRU).   Result  The experimental results show that the convergence of the GRU-based electrocution diagnosis model is good, and the recognition rate reaches 98.33%.   Conclusion  The method provides new insights for the research and development of a new generation of residual current protection devices and offers an effective guarantee for electrical safety.
Analysis of the Influence of Coil Placement on Pulsed Eddy Current Detection
ZHU Qi, WANG Qin, HAN Yang, ZHANG Yalin
2024, 11(4): 137-143. doi: 10.16516/j.ceec.2024.4.14
Abstract:
  Introduction  In the nuclear power plant, the steam pipeline is generally installed with an insulation layer on the outer wall to improve heat transfer efficiency. Currently, the main detection means for ferromagnetic pipelines are conventional ultrasound and ultrasonic guided waves. Prior to the inspection, the insulation layer on the outer wall of the pipeline needs to be removed, leading to extended inspection time, increased labor costs, and an inability to meet the requirements for high-quality development in nuclear power plants. The application of the pulsed eddy current (PEC) technique for nuclear power plants can eliminate the need for insulation layer removal, enabling non-stop online screening. The defects testing by coil placement is an essential indicator of the PEC technique.   Method  In this paper, the modeling and simulation of the pipelines was conducted by applying ANSYS Maxwell, coaxial and vertical detection coils were designed respectively to simulate the detection capability of PEC on flat bottom defects with consistency in the lift-off distance, materials and other conditions. Sample pipes were selected from the nuclear power plant for coaxial and vertical PEC testing. The pulsed eddy current testing (PECT) results were cross-validated with ultrasonic thickness measurement, and the effects of two coil placement methods on PECT were compared.   Result  The results show that vertical coils are more effective in defect detection compared to coaxial coils.   Conclusion  The defects testing by coil placement has great significance for implementing PEC in the nuclear power sector.
A Methodology for Yellow Non-Nitrate Smoke Emission During the Full-Process Startup of A Gas Turbine Power Plant
ZHANG Shikai, CHENG Shuo, HUANG Qing, ZHOU Jian, ZHU Weidong, TANG Yin
2024, 11(4): 144-155. doi: 10.16516/j.ceec.2024.4.15
Abstract:
  Introduction  The gas turbine generator set (GE-PG9351FA) with a DLN2.0 + burner and a designed NOx emission concentration of 50 mg/m3 is used in a gas turbine power plant. During the warm-up periods, the generator set emitted a large amount of yellow smoke, which violates provisions stipulated in the "Emission Standard for Air Pollutants from Thermal Power Plants" (GB 13223—2011) and is complained by the surrounding residents. According to the new emission regulations for environmental protection in Jiangsu, starting from January 1, 2023, the converted NOx emission average throughout the operation period should be less than 30 mg/m3. In order to meet this requirement and reduce the emission of yellow nitrate smoke during start-up, the renovated SCR denitration technology for the flue gas of the HRSG (Heat Recovery Steam Generator) is adopted. Data simulation, deduction, analysis and summarization of various indicators are conducted during the start-up process to refine a reasonable startup operation method.   Method  To validate the feasibility of this method, the power plant conducted multiple peak shaving start-up process operation tests. Based on the actual NOx emission characteristics, adjustments were made to the start-up point, gas turbine load control, and input nodes for the SCR system in the operation method. This process resulted in an optimized operational strategy.   Result  The test results show that by optimizing the SCR denitration system input point, gas turbine start-up point and warm-up load after grid connection, the converted NOx emission average throughout the operation period is less than 30 mg/m3, and the phenomenon of yellow nitrate smoke disappeared.   Conclusion  This strategy is based on the characteristics of NOx and yellow nitrate smoke emission during the gas turbine start-up process. Afterward, through data deduction and numerous experiments for validation, it can provide direct guidance for reducing yellow nitrate smoke emission during the start-up process of similar gas turbines. Additionally, it can serve as an analytical reference for controlling NOx emissions during peak shaving operations in gas turbine power plants.
From BIPV (Building Integrated Photovoltaic) to BIPVES (Building Integrated Photovoltaic and Energy Storage)
JIANG Yang, JIANG Xulai, ZHANG Qingnan, MIN Jie, CAI Rujian, WANG Yajie
2024, 11(4): 156-163. doi: 10.16516/j.ceec.2024.4.16
Abstract:
  Introduction  With the development of photovoltaics, energy storage, new building materials and prefabricated construction industry, Building Integrated Photovoltaic (BIPV) technology which features the integrated design and manufacturing of photovoltaic modules with components such as roofs, walls and sunshades is evolving as Building Integrated Photovoltaic and Energy Storage (BIPVES) technology.   Method  The article proposed the world's first rechargeable cement-based battery, promoting the integration of building walls with photovoltaic power generation and storage and discharging devices. Cross-disciplinary innovation was applied to equipment and materials, where high-definition, high transmittance patterned designs were printed on glass surfaces to manufacture high-efficiency photovoltaic building materials. Prefabricated energy storage walls were developed and integrated with various steel-structure prefabricated building systems to achieve customized production and prefabricated construction, leading to a transformative trend of integrating building components with photovoltaics and energy storage.   Result  Cement-based batteries allow building walls to have multiple functions, including photovoltaic power generation, energy storage and power supply; The new generation of photovoltaic building materials helps save costs on building facade decoration materials and reduce building carbon emissions; The integration of photovoltaics, energy storage and renewable energy technologies in buildings can achieve maximum benefits.   Conclusion  The new photovoltaic building materials and new energy storage technologies such as cement-based batteries show promising prospects. Combining and integrating rechargeable battery components, photovoltaic exterior panels, prefabricated building walls and embedded parts for widespread application is feasible.
Design of Gas Turbine Fuel Gas Transmission Pipe Under the Condition of Natural Gas Mixed with Hydrogen Gas
ZHU Junhui
2024, 11(4): 164-171. doi: 10.16516/j.ceec.2024.4.17
Abstract:
  Introduction  With the development of "3060" double carbon target, the usage of the PV and wind power for hydrogen gas production is becoming a hot and cutting-edge direction. The combustion of natural gas mixed with hydrogen gas in gas turbine of hydrogen gas industry will become the final step to convert hydrogen into electric power. The gas turbine unit have pressure regulation station, front module and connection pipe. The front module have requirements on the flow rate, pressure, temperature and particle content. And the pressure regulation station will provide the required mixed gas to front module. The connection pipe will have a length of 1 000 m which depended on the different arrangement. The character of pressure drop and temperature drop of connection pipe will have direct impact on the interface parameter of pressure regulation station. So it is necessary to study the character of pressure drop and temperature drop of connection pipe. And it will provide a practicable solution for the future gas turbine fired with natural gas mixed with hydrogen gas.   Method  The fuel demand was given for the H class gas turbine fired with mixture of natural gas and hydrogen gas after the simulation calculation with GT Pro software. The recommended material selection and velocity selection were presented based on required temperature and pressure drop by H class gas turbine front module and the physical character of mixed gas. The pipe pressure drop and temperature drop due to pressure drop were also calculated.   Result  The pipe material selection, diameter selection, pipe pressure drop and temperature drop due to pressure drop of pipe are presented.   Conclusion  For present time, the pipe design between natural gas pressure regulation station and gas turbine front module shall evaluate the material, outer diameter, wall thickness, velocity, pipe resistance, etc., each by each under the condition with hydrogen gas mixture. Thus the gas turbine can use natural gas at present phase and can be shifted to combustion with mixed hydrogen gas smoothly.
Handover Test Method and Application of Electrical Primary Equipment in 500 kV Offshore Booster Station
LI Haoliang, PAN Jiannan, LIANG Ruqing
2024, 11(4): 172-179. doi: 10.16516/j.ceec.2024.4.18
Abstract:
  Introduction  This paper explores multiple issues including the voltage application method, test voltage standard, test casing layout, and test item sequence for the handover test of the electrical primary equipment of the world's first 500 kV offshore booster station.   Method  Based on the test conditions and requirements, a comparison and analysis of the test voltage values and the insulation strength of the equipment were conducted. According to the structural characteristics of GIS and cables, the method of jointly testing GIS and cables was used to apply voltage to the cables. Considering the spatial environment and maximum insulation distance of the offshore booster station, the 500 kV GIS withstand voltage test casing was arranged outside the booster station. By comparing the test voltage values of the test items for 500 kV and 66 kV distribution equipment, the test item sequence was arranged rationally.   Result  The voltage application method for the withstand voltage test of the medium voltage winding of the main transformer, the voltage standard for the 66 kV GIS test, and the sequence of test items for cables and GIS equipment are determined. The handover tests of transformers, cables, and GIS are completed at the manufacturing base.   Conclusion  The handover test method for the electrical primary equipment of the world's first 500 kV offshore booster station can be used to simplify the test preparation work and shorten the test period. The method demonstrates certain engineering application value and can be used as references for other offshore booster station projects.
Pile Driving Construction Process and Application of Offshore Wind Turbine Monopile Foundation
WANG Yaowu, ZHENG Kangsheng, ZHANG Jihai, ZHU Tingjin, LI Dachao, LUO Bixiong, FAN Yongchun, ZHAO Dawen, CHI Yuanqing, LIU Donghua, ZHANG Yongkang
2024, 11(4): 180-189. doi: 10.16516/j.ceec.2024.4.19
Abstract:
  Introduction  Offshore wind power generation is gradually being widely applied in the global energy structure transformation due to its advantages of high annual power generation and stable power generation. However, due to the complex and ever-changing marine environment for offshore wind turbine construction, this poses significant obstacles to the construction process and technical solutions of offshore wind turbine foundations.   Method  In the context of the construction project of a certain offshore wind farm, this paper analyzed the type selection criteria and feasibility of pile driving construction ships, pile stabilizing platforms and hydraulic pile hammers. At the same time, in response to the construction requirements for wind turbine foundation pile driving, the preparation work before the operation, the construction plan for the pile stabilizing platform, and the wind turbine foundation pile driving operation with the cooperation of the main-auxiliary crane ships were emphasized. Furthermore, the control and correction measures for verticality in wind turbine foundation pile driving were analyzed.   Result  Steel pipe pile driving construction process can effectively ensure the project quality and expected progress, and has significant economic benefits, safety and reliability. During the pile driving process, it's necessary to complete preliminary and final adjustments to the verticality accural control.   Conclusion  Through the study of pile driving construction technology for offshore wind turbine foundations, it will provide useful reference and inspiration for similar offshore wind turbine projects.