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RSS2022 Vol. 9, No. 1
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2022, 9(1): 1-8.
doi: 10.16516/j.gedi.issn2095-8676.2022.01.001
Abstract:
Introduction In order to cope with the huge challenges of the development of offshore wind power industry in the grid parity stage and promote the sustainable and healthy development of the offshore wind power industry, Method based on experience from some design-led EPC projects in China, the application of EPC mode in power engineering was analyzed, the current unique challenges and countermeasures of offshore wind power project EPC management were put forward, and the main advantages of design-led offshore wind power project in the grid parity stage were summarized from the macro level. Result The research shows that the EPC mode is of great help to the cost reduction and efficiency increase of offshore wind power, especially the design-led EPC mode, which effectively mobilizes the forces of all links in the industry chain to reduce costs and increase efficiency. Conclusion The research results provide a useful reference for promoting the sustainable development of offshore wind power in the grid parity stage, and will effectively promote the high-quality development of deep sea offshore wind farms in the grid parity stage.
2022, 9(1): 9-19.
doi: 10.16516/j.gedi.issn2095-8676.2022.01.002
Abstract:
Introduction Offshore wind turbine installation vessel and wind turbine equipment faults occur frequently. In order to reduce the frequency of faults, new requirements and specific fault countermeasures need to be proposed for the installation vessel and equipment. Method Through the comparative research and analysis of the fault types of wind turbine vessel and equipment, the causes of each fault type were deeply analyzed and corresponding countermeasures were proposed. Result In the construction of offshore wind turbine, the installation vessel and the main wind turbine equipment are two major engineering instruments, which are most likely to break down. By adopting the fault countermeasures proposed in the paper, the occurrence of fault can be avoided to the greatest extent and the service life of the equipment can be improved to the maximum extent. Conclusion By summarizing the recent offshore wind power faults, it is found that the main reasons for the faults are improper operation and extreme sea conditions. In the process of wind farm construction, operation and maintenance, it is necessary to adopt corresponding fault countermeasures.
2022, 9(1): 20-28.
doi: 10.16516/j.gedi.issn2095-8676.2022.01.003
Abstract:
Introduction The ship resistance directly affects the fast performance of the ship, for an offshore wind farm service vessel, the fast performance is one of the important performance indexes. Therefore, it is necessary to calculate the ship resistance and study the effective resistance optimization method. Method Based on the CFD method, a numerical model was established to study the resistance performance of a 19.1 m-long catamaran offshore wind farm service vessel, the resistance of the ship at four different speeds of 10 kn, 13 kn, 16 kn and 20 kn were calculated and analyzed, and a stern flap was installed at the stern of the ship as the optimization method. Three stern flap schemes with different installation angles were designed. The ships before and after optimization were numerically simulated, and the calculation results were compared and analyzed. Result The research shows that the installation of stern flap with appropriate installation angle at the stern of the ship can effectively improve the resistance performance of the ship during navigation. The resistance reduction effect is ideal. The optimization method can change the navigation attitude of the ship and reduce the heave and trim angle of the ship during navigation. Conclusion The research results can provide reference for the calculation of ship resistance performance and the design of optimization method.
2022, 9(1): 29-33.
doi: 10.16516/j.gedi.issn2095-8676.2022.01.004
Abstract:
Introduction With the accelerated evolution of the national energy structure, offshore wind power will enter a period of rapid and stable development. At present, the development of offshore wind power near the shore of many provinces in China is nearly completed, and the offshore wind power is gradually developed to the offshore deep water area and will expand to a large scale. Offshore wind power in deep water areas has higher technical requirements for marine geotechnical investigation, and marine geotechnical investigation vessels and equipment need to be professional. But the number of large scale professional marine geotechnical investigation platforms in China is limited and they mainly serve the national marine resource exploration and scientific research work. They are rarely used for offshore wind power geotechnical investigation and the investigation costs are high. The traditional investigation mode of modified marine engineering (cargo) vessels with conventional drilling equipment is no longer suitable for offshore deep water area, nor for marine investigation operations in the short window period. Therefore, it is necessary to conduct in-depth research on the technology of marine geotechnical investigation platform. Method Through the research on the domestic marine geotechnical investigation vessel platform and exploration equipment, a comprehensive comparative analysis was carried out on their applicable water depth, ability to resist wind and wave, operation efficiency and investigation quality. According to the geotechnical investigation characteristics of offshore wind power and the sea condition of its development and utilization, the construction ideas and schemes of offshore geotechnical investigation platform for offshore wind power in deep water areas were proposed. Result The investigation practice of several offshore wind power projects has proved that the construction scheme of marine geotechnical investigation platform proposed in this paper can be applied to offshore deep water area operation, and can make full use of the 24-48 hour window period of marine investigation. Conclusion The scheme proposed in this paper is reasonable, which can effectively improve investigation efficiency, ensure the investigation progress and reduce investigation costs.
2022, 9(1): 34-39.
doi: 10.16516/j.gedi.issn2095-8676.2022.01.005
Abstract:
Introduction In order to optimize the progress control in the EPC construction process of offshore wind power project and pay close attention to the key points of project progress control with limited management resources, an offshore wind power progress control method based on risk management is proposed. Method Through project risk management, the progress risks that may cause significant delay to the project progress were analyzed and identified, and corresponding risk response measures were taken to avoid or reduce the construction period delay to the greatest extent. Taking two offshore wind power projects as examples, the feasibility of this method was verified. Result The results show that the offshore wind power schedule control method based on risk management can effectively identify the work priorities in schedule management, combine plan management and control with consideration of risk contradictions, realize the effective promotion of project progress, help to concentrate resources to solve risks and avoid or reduce construction delay. Conclusion The research in this paper can provide reference for schedule management of similar projects.
2022, 9(1): 40-46.
doi: 10.16516/j.gedi.issn2095-8676.2022.01.006
Abstract:
Introduction In the process of accelerating the construction of new power system with new energy as the main body, giving full play to the leverage effect of venture capital is conducive to promoting the rapid formation of scale economic advantages of new energy power generation, and promoting the achievement transformation and industrial implementation of new energy strategic emerging industries. Method Therefore, the theory of venture capital and risk management was introduced into the practice of new energy development and construction, and the related theories of strategic management, venture capital and new energy development and construction were integrated to construct the whole cycle risk management index system of new energy venture capital in this paper. The four elements of risk management and their work contents were put forward, a closed-loop risk management was formed, and the macro and micro elements were comprehensively considered, then the index system of risk identification and evaluation and its quantitative weight were designed from the aspects of industry policy, market environment, competitors and the economic benefits of the project itself, and the content, process and interface of risk report and control were defined. Result The practicality of new energy venture capital is enhanced. Conclusion The research results of this paper can provide operational reference for the introduction of venture capital and effective risk control in the new energy industry.
2022, 9(1): 47-51.
doi: 10.16516/j.gedi.issn2095-8676.2022.01.007
Abstract:
Introduction With the rapid development of offshore wind power in China, large diameter pile without transition piece has been widely used . This foundation avoids the disadvantage of monopile with transition piece, but result in high demand of construction equipment and the verticality is difficult to control. Method Taking a offshore wind power project in Guangdong as an example, the key technologies of pile driving construction for monopile without transition piece were comprehensively expounded in this paper. Result The construction plan of monopile driving is being proven high efficiency, safety, reliability, and cost-effectiveness. Conclusion Key technologie of pile driving construction for monopile has certain guiding significance for similar projects.
2022, 9(1): 52-57.
doi: 10.16516/j.gedi.issn2095-8676.2022.01.008
Abstract:
Introduction This paper aims to reduce the risk of shutdown or heavy loss of regional oil fields caused by platform fire in offshore substation. Method Taking an offshore substation as an example, the adaptability and application scope of high pressure water mist fire extinguishing system were analyzed. Through the benchmarking analysis and calculation of domestic and foreign specifications and equipment parameter characteristics, the parameter selection and application methods of different fire extinguishing types of electrical equipment in offshore substations were proposed. Result The study shows that the local application system of high pressure water mist is suitable for the oil-containing electrical primary equipment and large room, and the spray intensity shall be not less than 1.5 L/(min·m2). When taking into account the equipment waterproof grade and equipment heat dissipation is not economical, heptafluoropropane fire extinguishing system should be used for electrical secondary equipment. Conclusion The research results can provide reference for the construction of fire extinguishing system in offshore substation.
2022, 9(1): 58-63.
doi: 10.16516/j.gedi.issn2095-8676.2022.01.009
Abstract:
Introduction Sea transportation is one of the governing conditions for the structural design of topside modules, the accuracy of load input directly affects the structural design of the topside. At present, domestic sea transportation design generally ignored the influence of hull deformation in topside design, which considers the hull as a rigid body, this assumption is not in line with the actual situation, it is necessary to analyze the influence of hull deformation on sea transportation design of the topside module. Method Firstly, the domestic sea transportation analysis methods were introduced. Then, combined with the classification society specification, the hull deformation was theoretically expounded, and how some multinational companies consider the influence of hull deformation on sea transportation design of topside module was introduced, the current sea transportation design method was improved. Result Based on real project calculation, it proves that structural stress is seriously small without considering the hull deformation load. With the development of marine engineering, we need to pay more attention to the influence of hull deformation on sea transportation design. Conclusion This paper explains the risk of traditional sea transportation design and provides an important basis for improving sea transportation design methods.
2022, 9(1): 64-70.
doi: 10.16516/j.gedi.issn2095-8676.2022.01.010
Abstract:
Introduction In order to ensure the safety of operation of offshore wind turbine, it is necessary to grasp the change of topography around the offshore wind turbine foundation. Method The multi-beam sounding system was used to monitor the terrain around the wind turbine for 6 times, and the high-precision and high-density underwater terrain point cloud data were obtained. Through the data processing and analysis of the point cloud data, the high-precision underwater terrain digital elevation model (DEM) was constructed. Through the superposition analysis of the DEM, the quantity of erosion in different periods was calculated. Finally, the change of terrain in different periods was displayed by 3D model, and the causes of erosion were analyzed. Result The most direct reason for the terrain change around the wind turbine is that when a strong typhoon passes through the sea area of the wind farm, the seabed and the local area of the wind turbine usually undergo a large overall change; The combined action of tidal current and waves is another important cause of local erosion and siltation of the seabed topography in this area. Conclusion The multi-beam sounding system is effective in monitoring the underwater topography, which can provide important data support for the safe operation and maintenance of offshore wind power. The practice of the project has a good reference significance for carrying out underwater topography monitoring of similar projects.
2022, 9(1): 71-75.
doi: 10.16516/j.gedi.issn2095-8676.2022.01.011
Abstract:
Introduction The solenoid pressurizer spray valve is one of the key valves for PWR nuclear power plant, and it is of great significance for nuclear power construction to realize the independent research and development of the valve. Method In this paper, Starting from the system functional requirements and technical parameter requirements of the solenoid pressurizer spray valve, the overall structure, proportional solenoid, middle thermal protection device, valve position detect and output device, control system with pilot disc of the independently-developed solenoid pressurizer spray valve were briefly introduced in this paper. Result Through this independent research and development, the design technology of the solenoid pressurizer spray valve is mastered, the technical difficulties of the electromagnetic drive structure and the adaptability of the valve working under high temperature and high pressure medium conditions are solved, the system functional requirement for pressurizer spray valve is realized. Conclusion The independently-developed solenoid pressurizer spray valve meets the development needs for third generation nuclear power plant, and can be popularized and applied.
2022, 9(1): 76-85.
doi: 10.16516/j.gedi.issn2095-8676.2022.01.012
Abstract:
Introduction During the earth return and metallic return mode conversion of China's HVDC transmission projects in operation, several MRTB (metallic return transfer breaker) or ERTB (earth return transfer breaker) oscillation platform arrester damage have occurred, leading to conversion failure. Therefore, it is necessary to study several modification plans of DC transfer breaker arrester. Method Regarding the characteristics of high energy absorption, long current flow time and high ratio of residual voltage to reference voltage of the DC transfer switch arrester, the calculation results of the arrester's absorbed energy, flow time and overvoltage were proposed to judge whether the two modification plans of increasing the number of arrester columns and increasing the number of valves in series per column could improve the operation environment of the arrester, and the impact on the insulation level of other equipment and the arrangement of equipment were also analyzed in this paper. Result Increasing the number of arrester columns has no obvious effect on improving the operation characteristics of the arrester. Increasing the number of valves in series per column can reduce the current flow time of the arrester but will increase the insulation level of the circuit breaker and the capacitor of the oscillation circuit. Conclusion It is not recommended to increase the number of columns or the number of valves in series per column of the HVDC transfer switch arrester in the existing converter station. It can be transferred at a lower power level to reduce the stress of the arrester. If the energy margin of the arrester is sufficient, measures can be taken to remove the faulty unit and continue operation in the event that the arrester fails due to valve defects.
2022, 9(1): 86-95.
doi: 10.16516/j.gedi.issn2095-8676.2022.01.013
Abstract:
Introduction The ultra-high voltage flexible DC valve hall has the characteristics of high height, large volume, and large heat generation of equipment. The air supply mode of the air conditioning in the valve hall can significantly affect the indoor temperature field, wind speed field, and pressure field. It is very important to study the air supply mode of air conditioning in valve hall to ensure the normal operation of heating equipment in valve hall. Method Ansys Fluent 19.2, a CFD simulation software, was used to simulate the valve hall in the horizontal side air supply mode of the spherical nozzle, and the problems in the temperature field, wind speed field and pressure field were analyzed. And they were improved by changing the air supply angle. In this study, three kinds of air supply angles were set for simulation : i=10°, i=20°, i=30°. Result In the case of the horizontal side air supply mode of the spherical nozzle, the average temperature of the air in the valve hall is 30.30 ℃, and the average temperature, maximum temperature, and minimum temperature of the valve body surface are 52.91 ℃, 62.93 ℃, 43.55 ℃ respectively. There is local high temperature on the valve body surface. When i=30°, the lowest average indoor air temperature is 30.27 ℃, and there is less static air area around the valve body. The lower limit of the maximum surface temperature of the valve body at four air supply angles is 61.66 ℃; when i=10° and 20°, the average air temperature in the valve hall is respectively 30.40 ℃, 30.45 ℃, the highest temperature of the valve body surface at these two air supply angles exceeds 63 ℃. Conclusion The best inclination angle of the spherical nozzle air supply in summer in the UHV flexible DC valve hall is 30°.
2022, 9(1): 96-102.
doi: 10.16516/j.gedi.issn2095-8676.2022.01.014
Abstract:
Introduction Tower weight and foundation concrete quantity are important indexes in transmission line engineering. By comparing the tower weight and foundation concrete quantity of 10 mm, 15 mm, 20 mm, 30 mm and 40 mm ice area typical towers used in YunGui interconnection channel project, this paper explores the influence of ice area on tower weight and foundation concrete quantity. Method The components of the tower were analyzed and the relationship between each component and the total weight of the tower was fully understood; Through the comparison and analysis of tower weight and foundation concrete quantity in different ice areas, the relationship between different ice areas and tower weight and foundation concrete quantity was studied. Result The analysis shows that for the tension tower, the proportion of the tower body below the variable slope to the total tower weight is the largest; for the tangent tower, the cross arm, the tower body above the variable slope and the tower body below the variable slope all account for a large proportion of the total tower weight; the influence of ice area on the weight of tangent tower is greater than that of tension tower, and the increase of tower weight in 30 mm ice area is the largest; the influence of ice area on the concrete content of tension tower foundation is greater than that of tangent tower, and the increase of concrete content of tower foundation in 30 mm ice area is the largest. Conclusion There is a certain proportional relationship between the structural quantities and different ice areas, which can provide a reference for the estimation of the quantities of DC transmission lines in the future.
2022, 9(1): 103-108.
doi: 10.16516/j.gedi.issn2095-8676.2022.01.015
Abstract:
Introduction Control the exchanged power of the regional tie-lines within a reasonable range, which is an important factor to ensure the stability of the power network. However, under some extreme operation modes, the exchanged power of the tie-lines may exceed the limit, especially the large-scale of new energy sources into the power grid, the power of the tie-lines between regions may fluctuate greatly. Therefore, necessary power flow control measures should be taken. Method Compared the power flow control methods of several main types of tie-lines and their characteristics, a flexible power flow control method based on multi-stage rapid switching reactor was put forward, and the specific control strategy was studied. Result Finally, based on the application of a regional power grid Tie-lines, the function of multi-stage fast switching reactor in controlling the exchange power of regional power grid tie-line was verified. Conclusion The results show that the power flow of the tie-line can be controlled flexibly and quickly by using the multi-stage fast switching reactor, and the overall technical economy is better.
2022, 9(1): 109-114.
doi: 10.16516/j.gedi.issn2095-8676.2022.01.016
Abstract:
Introduction The gridding has been adopted by more and more power grid enterprises as its good performance in reliability management, line loss management and operating maintenance. At present, the power grid enterprises only set overall reliability targets instead of gridding reliability objectives, and the gridding still adopts standards of construction of power supply zones, which leads to high demands in power supply reliability but low planning and construction standard in cities with large differences in development. Method The influence of political, economic, load and other factors on power grid was found through mathematical statistics, and quantitative results were formed. Then, different gridding categories were divided with cluster analysis. Considering the historical outage household numbers and proportion of planned outages, the relations between average outage time and total outage time in different types of power grids were sort out with analytic hierarchy process (AHP), and the reliability target of the planning area was reasonably allocated to the gridding. Result The method meets the requirments of reliability objectives and actual demands in grid power supply construction, which is convenient for lean planning and construction of power network in gridding. Conclusion The examples in this paper show that the method has strong guiding significance forreliability targets and distribution network construction.
2022, 9(1): 115-121.
doi: 10.16516/j.gedi.issn2095-8676.2022.01.017
Abstract:
Introduction Voltage sag is one of the most serious power quality problems in distribution network. At present, due to the lack of a system to locate the source of voltage sag, the problem of responsibility division and attribution has always been the difficulty in dealing with voltage sag accidents. It is an effective way to solve the problem of voltage sag traceability by monitoring and analyzing the synchronous power quality measurement data of distribution network. Method Firstly, the architecture and fusion scheme of the integration of synchronous phasor and power quality measurement were analyzed, and a method of voltage sag source tracing and location based on real-time synchronous measurement data was proposed. Then, the case design scheme of distribution network demonstration project was proposed. Finally, the application of synchronous phasor and power quality measurement integration in intelligent distribution network was summarized in this paper. Results The results of demonstration construction verify the feasibility of the proposed design scheme. Conclusion The demonstration project has accumulated engineering experience for subsequent large-scale promotion and replication.
2022, 9(1): 122-129.
doi: 10.16516/j.gedi.issn2095-8676.2022.01.018
Abstract:
Introduction Aiming at allocating renewable energy consumption responsibility weight problem among market subjects, an allocation method based on evolutionary game and stochastic optimization is proposed. Method First of all, each market subject was taken as a limited rational individual participate in the weakly linked evolutionary game, and the absorption weight undertaking scheme that minimizes its own cost in the evolutionary equilibriumwas obtained and the selection strategy tendency of each market subject under the probability interval of different rewards and punishments adopted by the government was obtained. Then, after getting the probability interval of different reward and punishment measures taken by the government, a stochastic optimization model was used to get the specific scheme of absorbing weight which couldminimize the cost of each subject in each probability interval. Result The effectiveness and practicability of the proposed method is verified by calculating the data of 170 market entities in a provincial power grid. Conclusion A new method and idea on the weight distribution method of renewable energy absorption responsibility is provided, and feasible suggestions for the government to strengthen the enthusiasm of market subjects in the absorption of renewable energyare put forward in this paper.
