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RSS2019 Vol. 6, No. 4
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2019, 6(4): 1-5.
doi: 10.16516/j.gedi.issn2095-8676.2019.04.001
Abstract:
[Introduction] New generation information technologies such as artificial intelligence, cloud computing, big data, Internet of Things (IoT), and mobile Internet are gradually becoming powerful engines for smart grids, and at the same time have greatly promoted the innovation and development of Unmanned Aerial Vehicle (UAV) technology. This paper combines the current situation of power inspection, starting from the technical development trend and industry application needs, and looks forward to the future development of UAV power inspection, in order to provide a theory and method reference for the in-depth integration of UAV technology and power inspection in the era of big data and artificial intelligence. [Method] This paper aimed at the full-service process of UAV power inspection, expounded the application of new generation information technology in UAV power inspection, and forecasted the intelligent trend of power inspection. [Result] (1) Intelligent flight platform: the drone is closely integrated with 5G communication, gradually leading the 5G network UAV from network integration, real-time era to intelligent era; (2) Intelligent patrol: the UAV intelligent control and other series of technologies bottleneck will be overcome, networked "fixed/mobile" drone intelligent airport are developed, and UAV power inspection will be all-weather, unmanned and intelligent; (3) Intelligent data analysis, introduction of artificial intelligence technology and continuous optimization of models will greatly improve fast and accurate inspection data intelligent analysis; (4) Integration of IoT, big data, cloud computing will improve the multi-dimensional data integration, state monitoring full coverage, data stream and business flow integration coupling, and achieve intelligent equipment state evaluation and prediction; (5) Comprehensive application of the new generation of information technology: the construction of intelligent operation and maintenance system, and intelligent control platform for drone power inspection, will effectively improve management, and create a new situation of power inspection. [Conclusion] The rapid development of the new generation of information technology in the future will promote the development of remote sensing technology for drones, and also drive the power industry into a new era of intelligence.
2019, 6(4): 6-12.
doi: 10.16516/j.gedi.issn2095-8676.2019.04.002
Abstract:
[Introduction] This paper presents an optimal expansion planning model for an energy hub with multiple energy systems. [Method] Energy hub represented a coupling among various energy infrastructures for supplying electricity, natural gas and heating loads. Combined heat and power (CHP) and natural gas furnaces were considered within the energy hub to convert energy into other forms. The multiple energy system planning problem would optimally determine appropriate investment candidates for generating units, transmission lines, natural gas furnaces, and CHPs that satisfy electricity and heating load forecasts and hub system constraints. [Result] The system performances associated with reliability, energy efficiency, and emission matrices is evaluated for the identified planning schedules. [Conclusion] Numerical simulations demonstrate the effectiveness of the proposed multiple energy system expansion planning approach based on energy hub.
2019, 6(4): 13-28.
doi: 10.16516/j.gedi.issn2095-8676.2019.04.003
Abstract:
[Introduction] Based on the limit equilibrium theory, an accurate approach is proposed to solve the ultimate bearing capacity of shallow strip footings under general conditions. [Method] The foundation soil is considered to be an ideal elastic-plastic material, which obeys the Mohr-Coulomb yield criterion, and is assumed to be an ideal continuous medium that is isotropic, homogeneous and incompressible or non-expansive. Through analyzing the relative motion and interaction between the footing and soil, the problem of the ultimate bearing capacity of shallow strip footings is divided into two categories. A minimum model with the total vertical ultimate bearing capacity as its objective function is established to solve the ultimate bearing capacity using the slip-line method with no need to make any assumptions on the plastic zone and non-plastic wedge in advance. A convenient and practical simplified method is also proposed for practical engineering purposes. Furthermore, the first category of the problem in the case of the same uniform surcharges on both sides of footing is the focus of the study: the applicable conditions of Terzaghi′s ultimate bearing capacity equation as well as the theoretical exact solutions to its three bearing capacity factors are derived, and a new bearing capacity equation is put forward as a replacement for Terzaghi′s equation. The geometric and mechanical similarity principle is proposed by a dimensionless analysis. [Result] The results show that for perfectly smooth footings, the total vertical ultimate bearing capacity obtained by the present method is in good agreement with those by existing methods; whereas for perfectly rough footings, the existing methods underestimate the ultimate bearing capacity. [Conclusion] The classic Prandtl mechanism is not the plastic failure mechanism of the ultimate bearing capacity problem of perfectly smooth footings on weightless soil.
2019, 6(4): 29-34.
doi: 10.16516/j.gedi.issn2095-8676.2019.04.004
Abstract:
[Introduction] In order to learn from the development experience of the Singapore power market, analyze its settlement and risk management characteristics, and provide suggestions for the construction of power market in South China. [Method] After a ten-day research and study on the Singapore′s power market, the author combined with her own experience in the construction of the power market in the southern region to form this paper. [Result] This paper briefly introduces the general situation of Singapore′s power market, systematically analyzes the settlement mechanism and settlement algorithm of Singapore′s power market, and introduces the characteristics of its power market risk management in detail. [Conclusion] The Singapore power market pays attention to the top-level design of the power market, the sound policies and regulations and rules system, the clear curing of core processes, and the diversification of talent reserves. It is worth learning from the process of building a regional integrated power market in Southern China.
2019, 6(4): 35-39.
doi: 10.16516/j.gedi.issn2095-8676.2019.04.005
Abstract:
[Introduction] The paper aims at the defects of full-load switch feeder fault handling and proposes a power network system based on multiple operating modes of full-load switch networking. The characteristics of the existing distribution network fault handling technology are analyzed, and the different components of the system are elaborated, including incoming line, intelligent terminal unit, load, tie line and trunk line. [Method] By using near communication between two adjacent intelligent terminal units, the system′s guarantee substation can be cancelled, and the logic criterion only needs to know its state and that of the adjacent switch. The constant parameter was set in a uniform and simply way, and the whole line fault processing is in a stepless coordination. The constant parameter setting is adaptive to the connection structure of various networks and the operation mode of the system, and it doesn′t need to be reset unless the physical structure of the line is changed. [Result] The test results show that each power distribution intelligent terminal with load prediction function can control one load switch or multiple load switches, which can be selected according to the site conditions. [Conclusion] The proposed system can handle faults rapidly and reliably in a variety of operating modes, and hence can be applied in practical distribution networks.
2019, 6(4): 40-46.
doi: 10.16516/j.gedi.issn2095-8676.2019.04.006
Abstract:
[Introduction] Flow sheet modification is an important method to reduce the high energy cost in carbon dioxide capture process by amine chemical absorption in coal-fired power plant. [Method] The performances of MEA and MDEA/PZ solution in three carbon dioxide capture processes with split flow modifications were simulated by Aspen plus soft. The effects of lean load and split ratio on CO2 regeneration heat duty and cold duty were analyzed, and stripping process property was revealed by analysis of concentration and temperature driving force. [Result] It showed that all the three split flow modifications can effectively reduce the heat and cold duty. The modification case 3 presented the best performance because this modification led to better distribution of driving force, reducing the irreversible loss significantly. [Conclusion] Compared to convention MEA process, MDEA/PZ process with the case 3 modification reduced the heat and cold duty by 35.36% and 71.42%, showing good potential in industrial application.
2019, 6(4): 47-53.
doi: 10.16516/j.gedi.issn2095-8676.2019.04.007
Abstract:
[Introduction] Subcritical and ultra-supercritical 300 MW level units dominates the main electrical market in China. The feasibility study on ultra-supercritical 350 MW unit and advice the parameters with the background of a power plant in Hainan is completed to promote the energy conservation and efficiency. [Method] The feasibility of ultra-supercritical 350 MW unit was analyzed in this paper. The aspects of the material of the main equipment, feasibility for auxiliary equipment and material of pipes were analyzed too. We also compared the data of thermal economy and sensitivity of coal price assuming that the unit ran on different parameters. [Result] The result demonstrates that the technology of ultra-supercritical 350 MW unit is feasible. The unit if runs on 25 MPa/600 ℃/600 ℃ has the best economic profit with the current level of equipment price and coal price. [Conclusion] The technology of ultra-supercritical 350 MW unit can be applied in our country. It has a higher economic profit and a lesser pollutant emissions if the unit runs on the suitable parameters.
2019, 6(4): 54-58.
doi: 10.16516/j.gedi.issn2095-8676.2019.04.008
Abstract:
[Introduction] The by-pass system of Zhuhai Power Station is designed by BTG company whose upgrade plan has been the prime focus of our group, since its function control by electric element using analog signal which leads to low reliability and regulation performance. [Method] In this investigation we measured the localize redundancy control method which was using a innovative structure mixed with XDC800B and ATOS, including the Xinhua DCS/DEH control system XDC800, the high and low pressure turbine by-pass valves and their spray control valves are controlled by xSV valve control card of XDC800 system and ATOS digital power amplifier card.In order to further improve the stability of by-pass control system, the undisturbed automatic switching function of high and low pressure by-pass valves and their spray control valves is realized by using self-developed redundant switching control board. [Result] The results shows that the function of new system is completely identical with the original imported equipment which also achieving higher data control precision and make the unit runs more stable, while the requirements of unit start and shutdown, pressure control and FCB function under complex operating conditions are fully meet. [Conclusion] Thus, we demonstrate the feasibility of the localize redundancy control method, and this this is a successful project suits to Zhuhai Power Station with small construction area, short period and high economic benefit; This work provides some guidance for further study on by-pass system upgrade in the field of power generation.
2019, 6(4): 59-63.
doi: 10.16516/j.gedi.issn2095-8676.2019.04.009
Abstract:
[Introduction] In order to analyze the reasonbility of the fan configuration of a 350 MW supercritical heating unit. [Method] In this paper, the single-row configuration and double-row fan configuration was compared, it took the reliability of fans, the requirements of engineering heating and minimum annual fee method into congsideration. [Result] The results demonstrate that the unstopped reliability rate of single-row fan configuration is slightly lower than double-row fan configuration. However, under the condition of high load operation, the heating supply reliability of single-row fan is higher.Single-row fan configuration econmic advantage is obvious.Therefore, it is more reasonable to adopt single-row fan for heating units which operats under high load operation for a long time. [Conclusion] The conclusion of this study is not only applicable to this project, but also can provide guidance for other heating unit.
2019, 6(4): 64-68.
doi: 10.16516/j.gedi.issn2095-8676.2019.04.010
Abstract:
[Introduction] Limestone-gypsum wet desulfurization is a flue gas desulfurization technology with the most extensive application and the most mature technology in coal-fired power plants. Limestone slurry preparation is one of the high-energy -consuming processes, which has complex production process and difficult to correspond to material consumption and energy consumption. There is no reasonable and effective energy consumption prediction model. In order to establish a reliable pulping system energy consumption model that can guide the optimization of production parameters. [Method] Based on actual operating data of a 600 MW power plant, the controllable quantity in the production process was selected as input, and the time-delay relationship between each input variable was adjusted by mutual information theory. The improved BP neural network combined with genetic algorithm (GA) was used to establish the unit pulp energy consumption model of the pulping system. [Result] The experimental results show that compared with the unadjusted timing GA-BP model and the standard BP algorithm model, the calculation results of the GA-BP model with time series adjustment can more accurately approach the actual production data of the pulping system. [Conclusion] The established model can be applied to the energy optimization study of the slurry preparation process.
2019, 6(4): 69-74.
doi: 10.16516/j.gedi.issn2095-8676.2019.04.011
Abstract:
[Introduction] The paper aims to establish a sparseness approach based sample distribution for LS-SVM models to solve the problem of excessive computation in the application of classical iterative shearing sparseness algorithm for the soft measurement model of the carbon content in flying ash. [Method] On the basis of calculating the feature space distance between the samples, global representative indicator is constructed by mixing together the density and dispersion. The original samples were sorted and pruned and the sparsenseness was realized according to the indicator. The LS-SVM soft measurement model of the carbon content in fly ash was applied to a 1 000 MW coal-fired power plant, the original training sample set was taken from the field operation data of the unit. [Result] The results show that the proposed algorithm can greatly reduce the capacity of the training set with tiny loss of the error performance and it can reduce the training and online prediction calculation work during the LS-SVM soft measurement model of the carbon content in fly ash. [Conclusion] The LS-SVM sparse algorithm proposed in this paper reduces the sample space from 90 to 30, which not only reduces the calculation scale, but also guarantees the calculation accuracy, while guaranteeing that the error is reduced by 0.01%. The algorithm can realize on-line soft measurement of carbon content in fly ash in industrial controllers with limited computing performance such as PLC, and can be extended to other parameters soft measurement systems in power plants.
2019, 6(4): 75-79.
doi: 10.16516/j.gedi.issn2095-8676.2019.04.012
Abstract:
[Introduction] Many foreign projects need to adopt American standards for design, and many engineers are not familiar with these. [Method] In order to facilitate the relevant engineer involving in foreign projects to quickly understand the differences between Chinese and American standards in the design of disinfection facilities in water treatment plant and provide a more reasonable design, this paper described in detail the Chinese and American standards for the design of disinfection facilities in water treatment plant, and made a detailed comparison of the chlorine dosage, dosing point, disinfection index and electro-chlorination system′s setting. [Result] The comparison results show that compared with the Chinese standard, the American Standard has a relatively wide range of dosage, high require-ments for salt quality, salt storage capacity, sodium hypochlorite storage tank capacity and flexible configuration of chlorine generation system. [Conclusion] This paper aims to provide some guidance and reference for American Standard Design Engineering in the future.
2019, 6(4): 80-85.
doi: 10.16516/j.gedi.issn2095-8676.2019.04.013
Abstract:
[Introduction] Offshore wind farms are characterized by long distance from shore, high costs of repair due to vessels involved and weather, long maintenance cycles and the fact that daily operations and maintenance is highly dependent on weather and sea state. It is then of vital importance to select a reliable main electrical wiring for reliable operations of offshore wind farms, optimal planning of maintenance and secure finance returns. [Method] Various design schemes for subsea cables, main transformers, electrical wiring on the high/medium voltage side and major electrical components on the offshore substation have been compared and assessed in this paper through calculating short-circuit currents, modeling and analyzing vibration and various operating scenarios. [Result] Based on the comparisons and assessments, the main electrical wiring scheme is recommended to use three-winding main transformers, circuit-transformer unit arrangement and cable connection on the low voltage side of transformer for main electrical wiring scheme. [Conclusion] The design for main electrical wiring scheme for a 400 MW offshore substation is proposed in this paper.
2019, 6(4): 86-92.
doi: 10.16516/j.gedi.issn2095-8676.2019.04.014
Abstract:
[Introduction] Currently the SIA (Sequential Iterated Approach) method and process are used in China′s offshore wind projects bidding stage. The wind turbine manufacture usually presents the tower′s design and guarantees the quantity. The whole support structure is hardly the lightest design. This paper aims to present the IDO (Integrated Design Approach) to search for the global optimum for the whole support structure. It also suggests that the wind turbine manufacture and the design institute could present the whole design plan together in the bidding stage to find the global optimum and reduce the offshore LCoE (Levelized Cost of Energy). [Method] To investigate the mechanisms of IDO, this paper compared the results of 18 designs with different tower bottom diameters and monopile diameters. [Result] The results we obtained demonstrate that by IDO the mass of the whole support structure is greatly lighter than the lightest tower design which is obtained by SIA. [Conclusion] This work provides some guidance for the further offshore wind project bidding plan. To reduce the LCoE of offshore wind projects, the IDO method and process could be adopted to obtain the feasible solution with the lightest whole support structure design.
2019, 6(4): 93-100.
doi: 10.16516/j.gedi.issn2095-8676.2019.04.015
Abstract:
[Introduction] Facilitated by the advancement of large diameter monopile fabrication and installation capacity, the application of monopile foundation is expanding into deeper water, a study on properties of deep water monopile foundation with different pile shape can provide reference for similar projects. [Method] In this paper, parameters of monopile foundations in a Guangdong-Yangjiang offshore wind farm were grouped according to cone location-high, medium and low, followed by a statistical analysis for pile shape selection regularity. [Result] It was found that large diameter high cone configuration may lead to high fatigue load, optimum cone position is determined by sang and clay content of upper layer soil, as well as mechanical properties of these stratums. [Conclusion] Through comparative analysis, lower cone configuration was suggested to be the best countermeasure for high fatigue load, sites with high sand content with relatively large angle of internal friction can reduce pile diameter by raising the cone section, while low cone section is suitable for sites with high content of soft clay. The mudline stiffness matrix determinant of optimized pile configuration was proposed to be an evaluation indicator of foundation stiffness, then the relationship between foundation stiffness and steel weight was studied.
2019, 6(4): 101-105.
doi: 10.16516/j.gedi.issn2095-8676.2019.04.016
Abstract:
[Introduction] In this paper, strength and toughness analysis under earthquake for the whole model of offshore substation is presented, performance of offshore substation is analyzed under effect of earthquake in the design reference period different exceedance probabilities. [Method] The seismic performance was evaluated by the results from response spectrum method for strength analysis and the pushover analysis method for toughness analysis. [Result] By analyzing performance of substation jacket platform and accessory structures, the seismic performance of the structure meets the requirement of "No damage under minor earthquake, Repairable under moderate earthquake, No collapsing under major earthquake" considering sufficient safety factor. [Conclusion] It shows that the offshore substation has good seismic performance.
2019, 6(4): 106-112.
doi: 10.16516/j.gedi.issn2095-8676.2019.04.017
Abstract:
[Introduction] In the coastal thermal power plant, the unit circulating cooling water system usually adopts the secondary circulation way, which needs to transfer water from the seaside to the front pool of the circulating pump house through the open water intake channel. An inverted trapezoidal section is generally used in the open water intake channel, while a rectangular section is generally used in the front pool of the circulating pump house. Therefore, the connection between the two requires an itd, which is connected from an inverted trapezoidal section to a rectangular section. [Method] In the engineering of the past, and flow in open channel water pump room link transition section of the former pool there are many kinds of forms, the most commonly used were divided into two kinds, one kind was through the connection of reinforced concrete box culvert, another was by reinforced concrete buttressed retaining wall connection, the former for wave conditions demand was not high, the latter for demanding wave conditions. [Result] Combined with the actual situation of the project site, a special curved surface transition scheme was innovatively proposed to connect the open water intake canal with the front pool of the pump house, and solve the connection difficulties and construction complexity of the transition section between the open water intake canal and the front pool of the pump house. This kind of special structure can not only give full play to the function of gravity retaining wall depending on backfilling soil and its own gravity resistance to sliding, but also reduce the occupied area and greatly reduce the project cost. [Conclusion] The engineering practice proves that this new type of curved surface transition section not only satisfies the actual use function of the site, but also saves the cost of the project and facilitates the construction.
2019, 6(4): 113-117.
doi: 10.16516/j.gedi.issn2095-8676.2019.04.018
Abstract:
[Introduction] The attachment and growth of Marine organisms in the water transfer system reduces the effective diameter of the water pipeline and the flow of seawater. In order to ensure the normal water transfer, it is necessary to prevent and control Marine organisms. [Method] Take a nuclear power plant as an example, this paper studied the Marine organisms control scheme of long-distance water transfer project through the field investigation and analysis of Marine organisms at the water intake and the dynamic simulation test. [Result] The results show that NaClO and non-oxidizing biocide add alternately at multiple points, and the control effect of Marine organisms is good. [Conclusion] The purpose of this paper is to provide a reference for the future Marine organisms control of similar projects.
2019, 6(4): 118-122.
doi: 10.16516/j.gedi.issn2095-8676.2019.04.019
Abstract:
[Introduction] Most of the nuclear power plants under construction and operation in China are coastal sites. According to the previous observation data and analysis, storm surge is the dominant condition in flood control design. There are few research results on tsunami, and there is a lack of engineering experience in the protection methods of structures against tsunami. After the Fukushima nuclear accident, the impact of the tsunami on the safety of nuclear power plants has been widely concerned by nuclear safety supervision, nuclear power practitioners and the public. In China, the tsunami protection level of nuclear power plants in operation has also been reviewed. [Method] Based on the characteristics of tsunami and taking a nuclear power plant in coastal China as an example, this paper carried out the tsunami protection review of nuclear power plant through the physical model test research of tsunami wave. [Result] The model test results show that under the action of tsunami wave, the level elevation of coastal nuclear power plants built in China is adequate for offshore tsunami protection. [Conclusion] Combining with the existing flood control measures in the sea area, further consideration should be given to the protection against possible earthquake and tsunami in Manila and Ryukyu trenches in order to increase the safety margin in the design of the subsequent newly built coastal nuclear power plant in the light of site conditions.
2019, 6(4): 123-130.
doi: 10.16516/j.gedi.issn2095-8676.2019.04.020
Abstract:
[Introduction] The transmission line load which applied on tower become lager and lager. In order to bearing the reaction, the flexible tower base plate with eight anchor bolts which used to connect the tower leg and foundation had been adopted commonly. But there isn′t any method to design this member in relative specification, so it is necessary to study the bearing capacity of base plate. [Method] This paper analyzed the bearing capacity by classical mechanics theory, finite element and full size experiment. [Result] Studies have shown that the stress of the base plate is unevenly distributed under tension force. [Conclusion] A new formula has been proposed. This formula has the reference value when design in project.
2019, 6(4): 131-136.
doi: 10.16516/j.gedi.issn2095-8676.2019.04.021
Abstract:
[Introduction] Low voltage flexible DC microgrid is a bridge between DC devices such as energy storage, electric car and mid-voltage DC power grid. As the DC technology develops and many more DC devices connecting to the grid, it′s feasible and necessary to develop low voltage flexible DC microgrid. DC current transformer is a chief component of low voltage flexible DC microgrid. [Method] This article analyzed typical application scenario of low voltage flexible DC microgrid and compared several types of DC current transformer. It analyzed the reliability and economy of DC current transformer. [Result] Under specified circumstance, for branches of higher requirements of precision, DC current transformer is equipped independently for protection and control, while for branches of low requirements DC current transformer is shared between protection and control. Under current technical level, it′s recommended to use resistor shunt or giant magnetoresistance sensors. [Conclusion] It′s proved that under current technical level, the analysis this article mentioned is correct and effective. This article also gives advice for application under other scenarios.
2019, 6(4): 137-143.
doi: 10.16516/j.gedi.issn2095-8676.2019.04.022
Abstract:
[Introduction] In order to solve the problem that the supporting cable is disconnected due to improper selection during the construction of the transmission line across the sealing network, based on the mechanical calculation method of the mechanical performance of the overhead line, a selection algorithm of the supporting cable is proposed to make the construction safe and efficient. [Method] Firstly, the tensile strength, expansion ratio and weight per unit length of the rope material were compared, and the material of the supporting cable, namely Dyneema rope, was determined; Then based on the equilibrium equation of overhead space mechanics, the mechanical calculation model of the bearing cable was derived; Finally, the selection algorithm of the supporting cable was proposed by the mechanical calculation model. [Result] Taking the Aksuku 750 kV substation delivery project as an example, the supporting cable selected by the supporting cable selection algorithm satisfies the construction requirements. [Conclusion] The verification results show that the proposed selection algorithm of the supporting cable is feasible and can provide guidance for practical application.
2019, 6(4): 144-151.
doi: 10.16516/j.gedi.issn2095-8676.2019.04.023
Abstract:
[Introduction] The real-time monitoring and regular inspection for the primary electrical equipment in valve hall is extremely important to safety operation of converter station. [Method] In this study we investigated the demand of regular inspection of ±800 kV VSC-HVDC converter station, combined with the character of valve hall and operational experience in of converter station. [Result] The complete solution of intelligent inspection system in enclosed valve hall of ±800 kV VSC-HVDC converter station is provided. [Conclusion] Therefore, due to highly integrated of the proposed solutions, the automation level of inspection works will be increased dramatically.
