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RSS2015 Vol. 2, No. 3
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2015, 2(3): 1-9.
doi: 10.16516/j.gedi.issn2095-8676.2015.03.001
Abstract:
CO2-Enhanced Oil Recovery (CO2-EOR) is a technique of enhancing oil recovery by injecting CO2 into oil reservoirs. It also realizes both CO2 utilization and CO2storage and thus is an important technique in the CCUS chain. In recent decade the application of CO2-EOR is extended rapidly from inland to offshore, as a respond to the increasing demand for offshore CO2 storage. This paper briefed the concept and application conditions of CO2-EOR, and introduced worldwide projects and technical developments on offshore CO2-EOR, including the "Next Generation" CO2-EOR technology. A first-order preliminary review on the potential of CO2-EOR in offshore sedimentary basins off China was given for the first time based on comparison and analysis of petroleum geology of the basins. The Bohai Bay Basin (offshore) and the Pearl River Mouth Basin are regarded as having the potential of non-miscible and miscible CO2-EOR, respectively. The CO2-EOR application in these basins might be able to bring several hundred million tons of incremental oil production and to store several hundred million tons of CO2 underground permanently. Further studies and evaluations are needed urgently.
2015, 2(3): 10-16.
doi: 10.16516/j.gedi.issn2095-8676.2015.03.002
Abstract:
As the reformation of energy system is going further in China, there are currently different views on the future energy structure and "Internet+ Energy" . A review is presented on the development history from smart energy system to energy internet at home and abroad. Then authors demonstrate their own understanding on energy internet and the importance of energy system reformation. In the future, the energy structure will be consisted of basic energy internet and higher levels of energy internet, with spirits of more openness, equality, interactivity and sharing. Human oriented is the original point of energy internet. Internet will provide tools to optimize all segments of energy system and finally benefits every customer with "best" energy service. More renewable energy is expected to be accommodated in the energy internet, with the important assistance from distributed energy on modulating and backup. As representing advanced productivity, the energy internet is expected to solve current energy problems, create a new field of energy service and help with the economic transformation in China.
2015, 2(3): 17-22.
doi: 10.16516/j.gedi.issn2095-8676.2015.03.003
Abstract:
The state council pointed out in a decision that power market reformation issued on March 15th in 2015 is the focus of our country in the future. The five-point requirements of energy revolution issued by XI Jinping from the National financial Leading Group meeting in June 2014, the national energy development plans(2014-2020) and energy economic priorities in 2015 are understood and analyzed. Through the analysis of the basic national conditions of our country the current, the energy difference between the energy internet and smart power grid, this paper puts forward that a new electric change is the inevitable choice of our country energy revolution, and expounds the new electric change on our country's important meaning and plays a role of promoting the development of our country.
2015, 2(3): 23-27.
doi: 10.16516/j.gedi.issn2095-8676.2015.03.004
Abstract:
This article introduces the corrosion environment and corrosion properties of offshore structures. It also introduces the selection and performance evaluation standards for heavy-duty coatings. It analyzes the general engineering cases with suitable heavy-duty anticorrosion coating system for offshore structures in harsh marine environments, then the suitable coating system for harsh marine environments are researched and established. The results show that the coating system offers great performance and meet the standard of NORSOK Standard M-501, which can ensure the safety and stability of the offshore structures in highly corrosive marine environments with wet, high-salt, alternation of drying and wetting, and immersion conditions.
2015, 2(3): 28-33.
doi: 10.16516/j.gedi.issn2095-8676.2015.03.005
Abstract:
Compared with the large wind farms in the north which are built in the relatively flat inland area, wind farms located in CSG(China Southern Power Grid) are built in the relatively complex terrain environment, such as onshore or hilly areas, which challenges the performance of wind power forecast system (WPFS) greatly. The purpose of the wind power forecasting system application research is to keep the forecasting precision of the system in the complex and changeable scene and meet the requirement by the users. This paper presents the solution to flexibility of WPFS based on the analysis of typical wind resource and wind power characteristics over CSG, and the actual arrangements and user requirements for WPFS as well. Then the framework of forecasting flexibility is proposed according to the three main technical links of WPFS: multiple data inputs, forecasting modeling and forecasting results' forms, providing guidance for the building of WPFS and forecasting precision improvement in view of engineering. To illustrate the idea in detail, historical data of wind farms in CSG is used as displaying samples for discussion.
2015, 2(3): 34-37.
doi: 10.16516/j.gedi.issn2095-8676.2015.03.006
Abstract:
The researches on estimation and evaluation for offshore wind farm integrated to the grid are introduced. Normally, planning and construction of a wind farm power integrated generation is assessed with technic and economic index respectively. Based on the comparison between the control need of wind farm power generation's integration to the main grid and the control technology nowadays, comprehensive estimation is to be put forward. The research difficulties of it are discussed at the end of the paper.
2015, 2(3): 38-42.
doi: 10.16516/j.gedi.issn2095-8676.2015.03.007
Abstract:
A rational planning scheme is critical for reliability of system and efficiency of utility. The ideas of planning based on short-term demand are considered to be the main reason of chaos network structure, difficult operation and low maintaining efficiency. In this paper, a grid-based planning method is proposed. Based on the established hierarchical model and division method of grids, the classification standards and constructions demand evaluation indexes are proposed. Therefore, planning, construction, operation, maintenance and marketing can be performed based on girds and the closed-loop optimization of multi-links can be achieved. A engineering practices of distribution system planning in the LH district indicated the correctness of the method proposed in this paper.
2015, 2(3): 43-46.
doi: 10.16516/j.gedi.issn2095-8676.2015.03.008
Abstract:
To meet the high location of special economic zone, national economic center city and international city, Shenzhen is carrying out its industrial structure optimization adjustment. In this case, power load characteristics of Shenzhen grid are changing accordingly. In this paper, load classification and classified load value of 10 kV feeders of the current Shenzhen grid are investigated and organized. Volume-weighted average method is used to calculate load composition of the grid in top loading operation mode topological structure. By summing up the calculation results, classified load essential properties of the Shenzhen grid are given.
2015, 2(3): 47-50.
doi: 10.16516/j.gedi.issn2095-8676.2015.03.009
Abstract:
This paper gives a brief introduction of the integrated power system data network status and the VPN division of the five southern provinces, and proposes the question in view of the present situation. By analysizing the existing VPN technology, we can choose suitable for the characteristics and demands of network integrated data grid technology. According to the problems and technical present situation, this paper researches the future power grid VPN construction model, and puts forward three kinds of development model. And selection model VPN is most suitable for the characteristics of power grid construction, network operation and maintenance management of the environment in order to complex, to fully guarantee the service isolation and safety.
2015, 2(3): 51-56.
doi: 10.16516/j.gedi.issn2095-8676.2015.03.010
Abstract:
With the social development and industrial structure adjusting constantly, the changing in electricity structure, Guangdong power system is facing a growing problem on peak-shaving capability, the lack of power load has become an important factor restricting the development of electric power. To involve cogeneration units in peak shaving is an effective way to solve the problem above. In this paper, by modeling the cogeneration units, We study the different relationship between combined cycle net output, heat supply and the generating heat rate, the power supply gas consumption, the heat-electricity ratio, and conclude the factors which affect the peak shaving regulating capacity and the range of peak shaving. Base on the analysis of peak-shaving capability of the cogeneration units, we can know the operating mode of regulating peak-load of the power system.
2015, 2(3): 57-61.
doi: 10.16516/j.gedi.issn2095-8676.2015.03.011
Abstract:
The load hierarchy in normal power dispatch and control center design is simple, so the power operate in low reliability. The power dispatch and control center design based on load hierarchy classify the load in details, which will optimize the power distribution and improve the power supply reliability in dispatch and control center. This paper introduces the design of dispatch and control center power supply based on load hierarchy, and faults in each type of load, then calculates the reliability level of each type of load with weighting method.
2015, 2(3): 62-66.
doi: 10.16516/j.gedi.issn2095-8676.2015.03.012
Abstract:
The paper consider a typical condition of the offshore wind farm project in China, which has a capacity of 300 MW, through a 220 kV line connected to the grid. The electrical single line diagram is discussed, then the paper presents the voltage of the offshore substation and the HV-submarine cable, the array cable topology and collector system switch configuration, the main transformer number, capacity and type selection scheme and the reactive power compensation scheme. The views on main problems of electrical design of offshore wind farm are proposed, which provide a reference for the electric design of offshore wind farm.
2015, 2(3): 67-71.
doi: 10.16516/j.gedi.issn2095-8676.2015.03.013
Abstract:
The topology design of collection system is an important part of electric design of offshore wind farm. The layout and switch configuration have a great influence on the economy and reliability of the collection system. By surveying the research and project achievements overall world, several kind of layouts and switch configurations of collection system are analyzed and compared in this article, then a proper solution to the wind farm case is given, as to the offshore wind farm in the future which has large capacity and long distance. The article prospects the trend of collection system design.
2015, 2(3): 72-75.
doi: 10.16516/j.gedi.issn2095-8676.2015.03.014
Abstract:
Zhuhai Guishan Offshore Wind Farm is the first big offshore wind project in the South China Sea. The wind turbine supporting structures have four significant engineering characteristics including offshore structure engineering, towering structure, dynamic equipment, both complicate and soft sea soil as well. Design of wind turbine support structures is one of the most critical and difficult techinical challenges in this project. In this paper, general design contents of supporting structures are introduced. Some key technical topics, like soil parameters and pile-substructure interaction, turbine-substructre-foundaton integrated analysis, frequecy window problem, structure fatigue analysis, corrosion prevention design and grouted connection design are emphasized in this paper.
2015, 2(3): 76-79.
doi: 10.16516/j.gedi.issn2095-8676.2015.03.015
Abstract:
The wind turbine foundation(WTF) is key supporting structures of wind turbines in offshore wind farm and also is important structures to ensure the normal operation of wind turbines for 25 years. WTF has characteristics of long design life, large investment and high inspection and maintenance difficulty. Corrosion protection measures must be taken to make sure WTF operates normally in its service life. Combined with an offshore wind farm project in the south China sea, this paper carries out research work on key link of WTF's protection, reasonable and effective design plan.
2015, 2(3): 80-85.
doi: 10.16516/j.gedi.issn2095-8676.2015.03.016
Abstract:
It is great theoretical and practical significance to carry out analysis of grouted connection in jacket foundation for understanding its mechanism of force transfer, ensuring safety performance of offshore wind turbine support structures and optimizing design of this part. In this study, DNV standard was firstly applied to conduct sensitivity analysis of parameters which affect performance of grouted connection. Then finite element software was used to simulate it and can effectively simulate the contact of grouts with wall of steel and grout's constitutive relationship. Finally, some inportant rules and conclusionts were drawn from parameter sensitivity analysis based on DNV standard. These conclusions facilitate a better understanding of mechanical characteristics of grouted connection in pre-piled jacket and help engineers to select the appropriate parameters for grouted connection design. Numerical simulation validates the reliability of grouted connection design.
2015, 2(3): 86-90.
doi: 10.16516/j.gedi.issn2095-8676.2015.03.017
Abstract:
Wind load is one of the dominating loads for offshore wind measurement mast, whose applied amount relates closely to safety and economical efficiency. A traditional wind load model includes merely an isolated upper mast, and calculation is based on the standard of Load Code for the Design of Building Structures. To give a better simulation of wind load, a full-coupled model containing both the upper mast and lower foundation was built for numerical anslysis, then a comparison with code method was made. To deal with the close loop relationship between wind load and natural frequency, iteration was introduced to solve for wind vibration coefficient. Through comparison, it was found that with identical input, wind load calculated by mumerical method is 6%~26% smaller than those from code method.
2015, 2(3): 91-94.
doi: 10.16516/j.gedi.issn2095-8676.2015.03.018
Abstract:
As salt mist corrosion, electrical equipments of the offshore substation are usually arranged in an enclosed space. However, it will bring great challenges for the cooling of equipments, espacially the main transformers which have the most quantity of heat.This paper analyses the challenges for the ONAN transformers in the offshore substation, and gives a design of the closed cycle water cooling system for the transformer. By the comparison in technology and economy of the two schemes, the conclusion shows that the OFWF transformer is more suitable than ONAN transformer for offshore substation.
2015, 2(3): 95-100.
doi: 10.16516/j.gedi.issn2095-8676.2015.03.019
Abstract:
Through 863 large wind farms transmission using VSC HVDC technique project, steel-reinforcement concrete hybrid structure was introduced to be used in the indoor converter station structure design, according to its both advantage of steel structure and reinforced concrete structure. This paper gave the process how to select the structural form, the structure characteristics and its technology advantages; the structure integral calculation and key component design calculation results were shown in the design; after comparing with the whole steel structure form both in technical and economic aspect, prospects of using steel-reinforcement concrete hybrid structure in indoor substations and its key matters in design was discussed, which will be a good reference for the design of steel-reinforcement concrete hybrid structure in indoor substation in the future.
2015, 2(3): 101-107.
doi: 10.16516/j.gedi.issn2095-8676.2015.03.020
Abstract:
Based on the Fluent software, we used the standard k-εmodel to close the Reynolds average equations and analyze the heat and mass transfer process in the three-dimensional of the natural draft wet cooling towers (NDWCT) for the specific project .We calculated the fields of air velocity and temperature inside and outside the cooling tower and established the relevant equations and gas-water two-phase heat and mass transfer theory models. Combined with the actual situation of the project, we deeply analyze the Flow Field of the cooling tower: 1) the existence of windshield board reduces the air flow around the tower side flow rate and increases the symmetry of the cooling tower inlet flow field, so that the uniformity of tower aerodynamic field was increased. Installation height and length of windshield board have a greater impact into the air flow field. Especially, the 11m high, 8m long windshield board improve the performance of # 1, # 2 cooling tower mostly. 2) Installation angle and blocks number of windshield board have certain impact into the air flow field.When the windshield board angle change from 0° to 20° and the blocks number change from 60 to 90, there was little changes of cooling performance between the two towers.
2015, 2(3): 108-111.
doi: 10.16516/j.gedi.issn2095-8676.2015.03.021
Abstract:
Based on the demand of EPC contract for MAO KHE 2×220 MW thermal power plant project in VIETNAM, after analyzing the technology and economy in detail, comparing with the different characters between 200 MW superhigh pressure turbine and 300 MW subcritical turbine, the subcritical parameters were introduced in the 220 MW turbine. By Optimizing blade type, reducing seal leakage and improving the efficiency of the turbine cylinder, the heat consumption rate decreased to 8 026 kJ/kWh. After the turbine operating successfully, each unit can save standard coal equivalent 10 161.5 ton per year. Therefore, it will improve the economy of power plant and create a greater economic benefits. Furthermore, it can provide a good reference for choosing high efficient turbine in the same class power unit.
2015, 2(3): 112-117.
doi: 10.16516/j.gedi.issn2095-8676.2015.03.022
Abstract:
Inorder to solve the difficulties of earth electrode site selection and environment problems in DC transmission engineering, the proposed solution is to reconstruct independent earth electrode to common earth electrode. The main performance such as step voltage, corrosion life, maximum temperature rise, conductor capacity must be verified during the transformation period, and according to the verification results to determine the corresponding transformation project. At the same time, the effect of earth electrode on AC power network, oil and gas pipeline, railway facilities should be reviewed.
2015, 2(3): 118-121.
doi: 10.16516/j.gedi.issn2095-8676.2015.03.023
Abstract:
Currently the auxiliary system of converter station provides more and independent types. Indeed, the drawbacks are obvious, for instant, it cannot be centralized control, much more operation and maintenance, lower efficiency and small reliability. According to research of auxiliary system characteristics of convertor station, this paper presents a strong implementation of intelligent auxiliary system to promote traditional auxiliary system to be intelligent, which it can be networking, integration and intelligent from their isolation and static system. Based on the practical application and information feedback in Guangdong Qiaoxiang-converter station, this intelligent auxiliary system is higher efficiency and then save the cost on the equipment and maintenance of convertor station to improve the intelligent level and comprehensive effect.
2015, 2(3): 122-126.
doi: 10.16516/j.gedi.issn2095-8676.2015.03.024
Abstract:
By the comparison and analysis between the seismic design codes of China and America about the seismic precaution criterion, the building classification, the site classification, the ground motion acceleration for structure design and the characteristic period, it presents differences of the seismic hazard characteristics between Chinese code and American code when determining the seismic precaution criterion and the ground motion acceleration for structure design because of the difference of seismic design concept, shows the relationship on the building and the site classification, also compare the relative parameters of the characteristic period, finally the conversion relationships between the parameters of ground motions in Chinese code and American code are proposed to provide the reference for the seismic design of overseas projects in the future.
2015, 2(3): 127-130.
doi: 10.16516/j.gedi.issn2095-8676.2015.03.025
Abstract:
Insufficient capacity to compensate for production platforms, require additional production wells on the platform platform.Platform additional production wells on the premise of meeting the needs, also need to be considered to avoid additional platforms on the old platform itself the adverse effects of structural strength and stability, while also reducing offshore investment and construction difficulties, in accordance with specifications designed to plug well tank platform structure.This project through combines site construction environment, design out up to positioning and the oriented role of m framework and the inverted plug pointed structure, from design, and built, and installation multifaceted analysis research, success completed plug-in platform and old platform sea installation docking, level degrees and the parallel degrees meet specification and the construction requirements, for platform repair wells machine track beam of high precision installation lay has based, also for follow-up outside spread platform provides has site experience.
2015, 2(3): 131-135.
doi: 10.16516/j.gedi.issn2095-8676.2015.03.026
Abstract:
Auxiliary power consumption is related to the unit net output and the unit net efficiency, which is an important technical and economical index of fossil fuel power plants. Especially for oversea turnkey project, auxiliary power consumption is an key performance index to be judged during the bidding stage and tested during the acceptance certificate stage. International common practice is used to illustrate the meaning and the common penalty about the auxiliary power consumption. Applicable calculation method of the auxiliary power consumption is given and also the measurement during the bidding stage. The conclusion of this paper will give an guidance for more and more Chinese enterprises which go abroad.
2015, 2(3): 136-139.
doi: 10.16516/j.gedi.issn2095-8676.2015.03.027
Abstract:
The damage of transmission tower under typhoon attack is introduced, including cross-arm breaking, line breaking and link fitting failure, etc. The type and the feature of the damage are studied. The research can provide reference for the construction of similar projects.
