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RSS2018 Vol. 5, No. 1
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2018, 5(1): 1-13.
doi: 10.16516/j.gedi.issn2095-8676.2018.01.001
Abstract:
The slip-line method is commonly used to solve the limit earth pressure on retaining walls, but to date, there are still a number of problems which have not yet been solved. Based on the limit equilibrium theory, the backfill 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 which is isotropic, homogeneous and incompressible (or non-expansive). Various factors of influence are considered in the calculation model. An elastic overburden is proposed as a replacement for traditional tension cracks. A new concept "stress singularity" and its stress boundary conditions are introduced, and a statically determinate and solvable mathematical model for the limit equilibrium problem is established without considering the stress-strain relationship of soil. The slip-line stress field in the plastic zone of the backfill is solved by using the slip-line method, following which the active earth pressure on retaining walls and the soil reaction on slip surface are derived. The geometric and mechanical similarity principle is first proposed by dimensionless analysis. The results show that the slip-line solution to active earth pressure is generally always greater than or equal to Coulomb′s solution and coincides with Rankine′s solution or the classical Coulomb′s solution that satisfies the non-singularity conditions. Hencky′s first and second theorems are not generally applicable.
2018, 5(1): 14-21,13.
doi: 10.16516/j.gedi.issn2095-8676.2018.01.002
Abstract:
The adsorption of radionuclides in soil media has become one of the key considerations in both site selection and safety evaluation of geological repository. In order to understand the adsorption behavior and mechanism of uranium on soil media from pre-selected sites of radioactive waste disposal sites, batch adsorption experiments were adopted to study the adsorption of U(VI) on mineralogical components in Shenzhen(SSD) soil and Yangjiang(YJ) soil. The effects of initial concentration of U(VI) and ionic strength were studied in detail and the adsorption mechanisms were discussed by kinetic model and isothermal adsorption model. The results show that the equilibrium absorption capacity of U(VI) on both SSD soil and YJ soil increase when the initial concentration of U(VI) increase, while the removal rates of U(VI) on SSD soil and YJ soil decrease from 97.07% and 91.56% to 88.55% and 87.93%, respectively. The adsorption of uranium is not sensitive to ionic strength, which indicates the major species form on SSD soil might be inner-sphere surface complexes. The pseudo-second-order kinetic model and Langmuir isothermal adsorption equation can be used to describe the adsorption of U(VI) on both SSD and YJ soil media, and all the relation coefficients are higher than 0.99. This work provides some guidance for further study of actinides adsorption model on the soil medium, and offers the basis to speculate the transport behavior of uranium in the environment.
2018, 5(1): 22-28.
doi: 10.16516/j.gedi.issn2095-8676.2018.01.003
Abstract:
Nuclear power is a typical high-tech industry. Shanghai is the birthplace of China′s nuclear power industry, from the construction of Qinshan nuclear power phase I gradually formed a relatively complete nuclear power equipment manufacturing and technical service industry system, realize the technical level from the two generation to the three generation, Shanghai Municipal Nuclear Power Office is a professional departments to play a positive role to promote the development of the nuclear power industry. In the future, along with the three generation of nuclear power construction batch and independent, Shanghai will play the advantage of industrial chain gathering, further enhance the development level of nuclear power technology and equipment, and contribute to the development of China′s nuclear power equipment industry and " Go Global" .
2018, 5(1): 29-34.
doi: 10.16516/j.gedi.issn2095-8676.2018.01.004
Abstract:
The evolution process of electricity market regulation in USA lasts for more than a century, which indicates that the regulatory system and the electricity market are mutually interacting with each other. Regulation and deregulation exist at the same time, and the regulatory rules keep making adjustments to the development of electricity market. On one hand, changes and developments of power industries bring challenges to the supervision, and then rules will be adjusted to the changes; on the other hand, new rules can guide the development of electricity market. This paper analyzed the evolution of American regulatory mechanisms of electricity market, which started in the 1920s and works till now. It also traced key events which brought about changes in the regulatory rules, discussed how the government designed the new rules, and showed what adjustments they made and their influences on the development of American electricity market.
2018, 5(1): 35-39,34.
doi: 10.16516/j.gedi.issn2095-8676.2018.01.005
Abstract:
Centralized collection technology of generation data is widely used in many power grid companies at present. To solve the abnormal data identification problem, this paper analyzed the different type of power generation. Then an abnormal data identification method of large-scale generation data based on cluster analysis was proposed. At last, the effectiveness of the proposed method was verified based on actual data from a province grid company.
2018, 5(1): 40-44.
doi: 10.16516/j.gedi.issn2095-8676.2018.01.006
Abstract:
The consistency of battery pack is a critical problem of high-capacity battery energy storage system. The balancing technology of battery management system is an effective solution to this problem. This paper made research on battery management system balancing technology of high-capacity energy storage system. Balancing technologies within the battery module, between the modules, within the phase and between the phases of battery system were introduced and discussed. The construction and realisation of 4-level balancing system were described. Through the application of 4-level balancing system of battery system, the effective dynamic balance of different levels of battery system was achieved, which has provided technical support for the long-life and effective utilisation of higher capacity battery system.
2018, 5(1): 45-50.
doi: 10.16516/j.gedi.issn2095-8676.2018.01.007
Abstract:
With the development of E-commerce and the change of business mode, express delivery has become an indispensable part of people′s life. All kinds of logistics and transportation vehicles are more burdened with the already overwhelming traffic. This paper discussed the country to develop the city infrastructure construction, to create wisdom metro, combined with the rapid development of underground traffic and underground pipe or tunnel opportunity, analyzed center city municipal facilities combined with the feasibility of logistics distribution automation; and combined with the networking and big data technology, made the whole logistics process more intelligent, automated and convenient, to relieve the road traffic pressure, reduce vehicle emissions, improve the transportation efficiency, and cooperate the development of new retail.
2018, 5(1): 51-58.
doi: 10.16516/j.gedi.issn2095-8676.2018.01.008
Abstract:
The increased focus on environmental protection and the problem of lack of fossil energy around the world has prompted the rapid development of electric vehicles(EVs). With the popularity of private EVs, the original load characteristics of the system would be changed by the charging behavior which would have an impact on the safety and economic operation of the distribution network. The Monte Carlo calculation model of the charging power of the urban residential district electric vehicle was set up according to the charging behavior of users in different scenarios, and the influence of EVs charging on residence community distribution network was analyzed. The effective demand side management strategy was put forward to guide the charging behavior of users to make the system security and reliability, so as to improve the impact on the network friendliness and weaken the adverse effects.
2018, 5(1): 59-62.
doi: 10.16516/j.gedi.issn2095-8676.2018.01.009
Abstract:
For the thermal power plant with FCB function, there are special requirements on design. By researching FCB transient and steady process, in contrast to normal power plant, we found out the important selection differences of bypass valve capacity, feedwater pump capacity and driving-turbine steam supplying, deaerator water storage capacity and heating-steam supplying, high pressure heater heating- steam supplying etc. Based on several engineerings design experience, we determined the correct selection of these auxiliary equipments. Thus, power plant can be realized FCB function safely and reliably. The method has important reference value for the design of FCB function power plant.
2018, 5(1): 63-67,72.
doi: 10.16516/j.gedi.issn2095-8676.2018.01.010
Abstract:
In order to solve the problem of pipeline pressure drop calculation accuracy, in this paper, based on comparison to the analysis algorithms of pipeline pressure drop in Soviet Union, Germany and U. S., combined with characteristics and performance of major steam piping in thermal power plant, an optimized and accurate algorithm of steam pipe pressure drop was proposed. The new algorithm eliminated deviation of the results in previous algorithm because of the difference of test conditions, theoretical calculations, manufacturing processes. New pipeline pressure drop algorithm for thermal power plant major steam piping provides a more effective way to optimize of layout and process of major pipeline.
2018, 5(1): 68-72.
doi: 10.16516/j.gedi.issn2095-8676.2018.01.011
Abstract:
The steam turbine regenerative extraction steam system is one of import systems for the power plant thermochemistry. It is all-important that researching the reasonable design process and main problem for observing. Research the reasonable design process according to the experience of designing and operating; Research the sixty-four-dollar-question and attendant main question according to the code of overseas or Chinese, so that the power plant can be operated safely and economically.
2018, 5(1): 73-80.
doi: 10.16516/j.gedi.issn2095-8676.2018.01.012
Abstract:
Combined with the judgment logic of combustion stability of existing FSSS system, a combustion stability discrimination method based on D-S (Dempster-Shafer) evidential theory was proposed for boiler combustion instability in power plant. This paper discussed the combustion conditions under different conditions of the flame, used the four flame monitoring signals of the single-layer burner combined with the size of the coal-to-air ratio and the fire signals of adjacent layers to establish a typical sample. It took typical sample as comparable data and computed the confidence density of ignition goal pattern and fire extinguishing goal pattern, then carried on normalized processing to the typical sample to obtain the confidence function distribution. In this paper, in a period of time within a layer of burner 4 fire monitoring signals, air-coal ratios and the adjacent layer of flames were selected as evidence, and combined with the typical sample database, the reliability function distribution and uncertainty of the evidence in each goal pattern were calculated. D-S joint rules were used to fuse the data to judge the combustion stability. The experimental result shows that the method is effective, and can not only improve the accuracy of the judgment result, but also reduce the subjectivity in the process of construction of reliability function, which is convenient for engineering application.
2018, 5(1): 81-85.
doi: 10.16516/j.gedi.issn2095-8676.2018.01.013
Abstract:
Currently, there are often some problems in the air volume measurement system, which leads to air volume measurement and calculations inaccurate. Therefore, a method for measuring air volume based on the amount of oxygen and heat was proposed. First of all, through the process of smoke composition analysis, the formula for calculating the air volume using the amount of oxygen in the flue gas was derived. Then, the calorific value of the coal was used instead of the heat in the formula. Finally, the amount of coal was used for dynamic compensation. The result of the formula calculation had the same dynamic response rate as the actual air volume. By conducting an experiment on a 600 MW unit, the formula was verified, and then comparing the measured volume of soft measurement with the actual air volume under different operating conditions, the oxygen-heat-based soft-sensing method was found to be very good. The real-time air volume was reflected, and the accuracy was high and the response speed was good, which can meet the needs of the site.For the problem that air volume cannot be accurately measured at this stage, this soft measurement method can be effectively solved and widely applied in power plants.
2018, 5(1): 86-91.
doi: 10.16516/j.gedi.issn2095-8676.2018.01.014
Abstract:
The two usual advanced utilization systems of boiler tail flue gas heat at present was introduced. The two systems were studied by the equivalent enthalpy drop theory, the thermal efficiency formula was deduced. Referring to THA condition of a 1 GW USC unit, the equivalent enthalpy drop theory was used for quantitative calculation and comparison of the two systems, the results show that: based on certain boundary conditions of the project and design principles, air preheater flue gas bypass system perfectly increases flue gas heat energy level, and that has better thermal efficiency and great energy-saving effects.
2018, 5(1): 92-97,58.
doi: 10.16516/j.gedi.issn2095-8676.2018.01.015
Abstract:
The design study of 1 100 kV DC switch yard for 1 100 kV converter substation was given in this paper. In this study, we proposed an indoor DC yard design principle, design processes and design methods. The main electrical parameters of the indoor DC yard were calculated and recommended results were shown. Three indoor designs and comparison were given considering 1 100 kV equipment characters, air clearance, installation and maintenance. It is proposed joint lifting work by double-crane can not only save investment on the construction of station and equipment, but also can save time and maintenance costs in the future.
2018, 5(1): 98-102.
doi: 10.16516/j.gedi.issn2095-8676.2018.01.016
Abstract:
Photovoltaic generation connected to 500 kV substation was studied in this paper. Firstly, the general wiring mode of 500 kV substation station power and the basic model of PV generation were introduced. According to the characteristics of 500 kV substation and the structure of the station, the layout of PV modules, power supply of PV generation and the scheme of PV connected to system are represented. Matlab simulation model of PV connected to 500 kV substation station power was established based on the actual parameters of 500 kV substation. Based on the Matlab simulation model, the short-circuit faults simulations were tested and calculated, the influences on station power protection of 500 kV substation were analyzed, and measures of station protection were also proposed.
2018, 5(1): 103-106.
doi: 10.16516/j.gedi.issn2095-8676.2018.01.017
Abstract:
In order to study the actual ground electric field distribution under the AC transmission line, the influence of the height of the conductor to the ground on the electric charge and the electric field was analyzed. The results show that: The influence of the height of the conductor to the ground has little effect on the electric charge; The influence of the height of the conductor to the ground electric field is very large under the condition that the charge quantity is unchanged. Therefore, under the assumption that the height has no influence on the charge of the conductor, considering the arc shape of the conductor, the actual electric field under AC transmission line was solved by the differential vector superposition method and the electric field distribution under UHV AC transmission line was taken an example for the calculation and verification. The analysis results show that the high field range below the line only exists near the middle span and the electric field intensity decreases rapidly with the distance away from the midspan which is very different with the ground electric field distribution calculated by the minimum height. The research results have important guiding significance for the judgment of the house demolition.
2018, 5(1): 107-112.
doi: 10.16516/j.gedi.issn2095-8676.2018.01.018
Abstract:
Flue gas desulfurization (FGD) with high content of salinity and heavy metals is the most criticial pollutant of concern in power plant, this paper introduced its characteristics and the main technologies that used in nowdays. Amony all of these technologies, reverse osmosis treatment, bypass flue gas evaporation technology with crystallizer and bypass flue gas evaporation technology with concentrator are the three promising technolgies. By mean of comparing their technical performances and costs, bypass flue gas evaporation technology with concentrator is the most promising technology because of its lower investment and operating costs, smaller footprint and more environmental friendly.
2018, 5(1): 113-117.
doi: 10.16516/j.gedi.issn2095-8676.2018.01.019
Abstract:
This paper mainly discussed the technical requirements and possible forms of fire water sources in nuclear power plants. Through the literature review of the nuclear power plant fire water, combined with the actual situation of China′s nuclear power plant, this paper discussed and analyzed the fire water requirements on water quality, reliability, and fire pump adapter and make up devices and the possible forms of fire water source, the results show that compared with the general requirements of fire water, in nuclear power plant, the guarantee rate of fire water is more demanding, fire pump adapter and the surge tank is useful. In the design of nuclear power plant fire water source should be considered to enhance the fire water requirements.
2018, 5(1): 118-121.
doi: 10.16516/j.gedi.issn2095-8676.2018.01.020
Abstract:
In the coast of our country, there are a lot of thermal power stations, these power facilities made great contributions for the economic development of our country, in the future economic development, also need to construct a number of such power stations, but coastal site resources are becoming less and less, which determines to make good use of every site, and do a good planning of every site. This article made a summary of experience and refining from thermal power stations which had been built , and put forward how to do a good planning in the thermal power station. Good plant planning can save the project cost for the investment, can accelerate the construction progress for the construction party, and can reduce the operation and maintenance cost for the running party, can play the overall maximum value of the power station.
2018, 5(1): 122-126.
doi: 10.16516/j.gedi.issn2095-8676.2018.01.021
Abstract:
The ignition technology is extremely important for lower operating cost and ignition reliability of coal-fired power plant. The article discussed ignition technology (oil-less ignition, plasma ignition, natural gas Ignition) about 1 000 MW double-reheat coal-fired power plant from technological aspect, and developed an economic evaluation based on the actual unit. The result shows that for 1 000 MW double-reheat power plant, oil-free ignition technology has lower operating cost. Because of no operation experience, the risks and countermeasures for 1 000 MW double-reheat unit to take oil-free ignition are processed furthermore to offer reference for execution. The integrated technoeconomic analysis method can also be applied for ignition technology selection about other capacity units with its broad applicability.
2018, 5(1): 127-131.
doi: 10.16516/j.gedi.issn2095-8676.2018.01.022
Abstract:
Relying on one 660 MW super critical "W" flame furnace coal-fired unit project, this article proposed a new proposal on the number of mill in pulverizing system. Through the technology and economic comparations between the general proposal of 6 mills and the new proposal of 4 mills, it was demonstrated that the new proposal of 4 sets double into and out mills is viable on technology, reliable on operation and good on economic benefit. This article proposed the new idea for drawing up the plan on pulverizing system of this type of unit.
2018, 5(1): 132-138.
doi: 10.16516/j.gedi.issn2095-8676.2018.01.023
Abstract:
Aiming at the over-reliance on the inefficient operation of transformers and circuit breakers in the field of substation, introduced the special advantages of fault wave recorder on-site monitoring of substation primary equipment, and expounded the technical principle of extracting transformer and circuit breaker state parameters by wave recording data. This paper presented a design scheme of remote on-line monitoring, acquisition, evaluation and distribution of integrated platform for transformer and circuit breaker equipment based on dispatching data network, and realized the wide area monitoring, information sorting, feature recognition, fault research and status evaluation, and introduced the long-term mechanism of regular feature library with self-learning ability to ensure the scientific and applicability of system decision-making. The operation effect of Guangzhou Power Supply Bureau has verified the accuracy of system failure judgment and potential defect prediction, and enhanced the state evaluation ability of transformer and circuit breaker, and raised the level of operation and maintenance of high equipment.
