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1.
ABSTRACTS     
YANG Xiong-jing 《内燃机车》2014,(7):I0001-I0002
This paper makes analysis and discus- sion of railway roiling stock market of the world, the posi- tion of CNR in the world and the condition of main multi- national corporations.  相似文献   

2.
This article indicates by example about power price of Henan province that the energy resources of Henan province are "the commons". According to analysis of the game of "the tragedy of the commons", this article demonstrates that, whether under complete information or not, energy commons are abused. Based upon the situation, the author gives out the strategy to solve "the tragedy of the commons" of China energy sources.  相似文献   

3.
Nowadays, global warming is a major environmental concern. Climate change is dominating the environmental agendas, especially in developed countries at first, but by now, around the world. Several initiatives have been undertaken to reduce the effect of increasing atmospheric GHGs (greenhouse gasses) concentrations. Emerging carbon emissions trade under the Kyoto Protocol serves to market the carbon quotas among the countries, thus, it helps to increase their level of GNP (gross national product). Emissions trade is being performed in the voluntary and compliant markets. Increasing interest in emission trade emerged carbon and energy exchanges markets in the world. Turkey is located in the voluntary markets, and organizations buying carbon offset credits in order to achieve their voluntary emission reduction goals. GS (gold standard) and VCS (verified carbon standard) are mainly being used to finance renewable energy projects in Turkey. In the GS, there are 209 projects which are currently in the approval process or in the application, such as wind energy, hydroelectric power plant and biogas energy production. In addition to these, in the VCS, there are 61 projects which are mainly energy industries, in the approval process or in the application. Most environmental issues require long-term plans which include international cooperation, especially climate change. The Kyoto Protocol marks the beginning of a new era to combat global climate change. Voluntary markets are very popular and forty percent of the total global GS projects and around nine percent of VCS projects are implemented in Turkey. These projects are initial steps for future implementations of compliant markets in Turkey.  相似文献   

4.
Based on the construction property of rolled compacted concrete, three-dimensional finite element relocating mesh method was developed in simulating construction process and computing temperature and stress field. Using this method, the temperature and the thermal stress fields developed in the RCC gravity dam of the Longtan project with or without a longitudinal joint during construction and operation are calculated so as to simulate the construction process. The computation results show that the value of the thermal stresses developed in the dam even, without any longitudinal joint, could meet the design criteria provided the placement temperature is adequately controlled.  相似文献   

5.
The authors have proposed the unique ocean wave power station, which is composed of the floating type platform with a pair of floats lining up at the interval of one wave pitch and the power unit where the runners are submerged at the middle of the platform. Such a profile can make the flow velocity at the runner twice faster than that of OWC (oscillating water column) type constructed adjacent to the seashore. The behavior of the platform in the wave has been reported, and this paper continuously investigates the effects of the runner casing on the runner work and the platform behavior. Besides, the flows around the Wells type, not only single runner but also tandem runners are investigated numerically. It was confirmed that the runner work attenuates the platform amplitude and the runner casing contributes to increase the output. The flow simulation suggests that the tandem runners may be appropriate for the floating type ocean wave power station to get enough output.  相似文献   

6.
According to the construction characteristic of RCC dam cast by layers, three-dimensional finite element relocating mesh method is developed to simulate construction process and compute temperature field. The computation model of relocating mesh method is expatiated in detail; based on the thermodynamic properties of RCC materials, the feasibility and error of relocating mesh method are analyzed and demonstrated; The computation results in this article are verified by means of the temperature observation data of certain RCC gravity dam. The results show that the temperature field computed by three-dimensional finite element relocating mesh method can not only ensure the computation precision, but also improve the calculation efficiency greatly. This provides an effective method for simulating construction process and computing temperature field of RCC dam.  相似文献   

7.
Experimental research was conducted on the stepped chute which connected with horizontal stilling basin directly. New date was presented on the pressure head alone the floor of the stilling basin and the characteristics of hydraulic jump. The experiment data indicated that the maximum pressure head was in the impact area of the stilling basin floor next to the chute. Smaller step size and steeper chute angle would cause bigger pressure head. The minimum value of the pressure head was found behind the impact area.  相似文献   

8.
Wind energy is currently a fast-growing interdisciplinary field that encompasses many different branches of engineering and science. Modeling and controlling wind energy systems are difficult and challenging problems. The basic structure of wind turbines and some wind control system methods are briefly reviewed. The need for using advanced theories from fuzzy and intelligent systems in studying wind energy systems is identified and justified. FCMs (fuzzy cognitive maps) are used to model wind energy systems. Simulation studies are performed and obtained results are discussed. A new mathematical approach has been proposed to model dynamical complex systems, the DYFUKN (dynamic fuzzy knowledge networks). Many open problems in the areas of modeling and controlling wind energy systems are outlined.  相似文献   

9.
This paper presents the neutron energy spectrum in the central position of a neutron flux trap assembled in the core center of the research nuclear reactor IPEN/MB-01, obtained by an unfolding method. To this end, we have used several different types of activation foils (Au, Sc, Ti, Ni, and plates) which have been irradiated in the central position of the reactor core (setting number 203) at a reactor power level (64.57±2.91 watts). The activation foils were counted by solid-state detector HPGe (high pure germanium detector) (gamma spectrometry). The experimental data of nuclear reaction rates (saturated activity per target nucleus) and a neutron spectrum estimated by a reactor physics computer code are the main input data to get the most suitable neutron spectrum in the irradiation position obtained through SANDBP (spectrum analysis neutron detection code-version Budapest University) code: a neutron spectra unfolding code that uses an iterative adjustment method. the integral neutron flux, (2.41 ± 0.01) × 10^9 n·cm^-2·s^-1 for the thermal The adjustment resulted in (3.85 ± 0.14) × 10^9 n·cm^-2·s^-1 for neutron flux, (1.09 ±0.02) × 10^9n·cm^-2·s^-1 for intermediate neutron flux and (3.41 ± 0.02) × 10^8 n·cm^-2·s^-1 for the fast neutrons flux. These results can be used to verify and validate the nuclear reactor codes and its associated nuclear data libraries, besides, show how much effective it can be that the use of a neutron flux trap in the nuclear reactor core to increase the thermal neutron flux without increase the operation reactor power level. The thermal neutral flux increased 4.04 ± 0.21 times compared with the standard configuration of the reactor core.  相似文献   

10.
In this paper, some key problems about operational risk assessment are well analyzed. The time-varying and condition-based component outage model was proposed, which can reflect the changes of weather and other operation conditions. A rank enumeration based system state selection method was used to perform risk assessment. Then, the problem of operational risk index was also addressed. In the last part of paper, two groups of numeral tests were presented. The first one showed that the risk assessment results using component instantaneous unavailability, are quite different from the results using steady unavailability, and proves that component outage model with instantaneous unavailability should be used for operational risk assessment; The other one shows that the proposed time-varying component outage model can reflect the operation conditions' influences on the risk assessment results.  相似文献   

11.
After the great east Japan earthquake in 2011, Japanese energy system has been expected to prioritize safety and trustworthiness. Now, distributed power systems are considered as one solution, but utilizing exhaust heat is an important task to be solved. The purpose of this study is to build a simulation model to harness waste heat of commercial buildings. We obtained two types of data: distributed power system in 1/15 scale model of supermarket, restaurant and real world energy consumption of the two buildings. Results showed cold cabinets, whose electricity was affected by temperatures outside and inside, consumed most in supermarket. While air conditioning, affected by air enthalpy of outside and inside, consumed most in restaurant. According to our simulation with gas engine, PV (photovoltaic) panel, PCM (phase change material), thermal storage, FCU (fan coil unit) and refrigerated cabinets in scale model, we could reduce 27% of CO_2 emission and 25% of running cost by selecting optimal size.  相似文献   

12.
Windbelt generators have been proposed as small, green power sources for battery charging applications. Some of the reported results lack detailed information about how key parameters influence the output power of the generator. In this work, we built prototypes with different architectures to study the voltage generation and power delivery as functions of belt tension, length, and electrical load at various wind speeds. We also studied the maximum power delivery conditions before the breakdown of the belt oscillation occurs. Our results are obtained from windbelt generators with two types of architectures: a conventional design with an adjustable belt that uses weight for tension control, and a revised design with a belt oscillation perpendicular to the coil axis. We have concluded that the breakdown of the belt oscillation at lower output resistances is a primary bottleneck that will limit windbelt systems to only very low power applications.  相似文献   

13.
Special interest in current interruptions is dedicated to the processes close to the current zero instant, the so-called interaction region, which determines the circuit breakers' performance. The quantities of interest in this region are the distribution of temperature, density and pressure, velocity and gas mass flow along the electric arc axis, as well as the distribution of electric stress between contacts Calculation of steady SF_6 gas flow through the nozzle of a 420 kV circuit breaker at the current zero instant, for different arcing durations, was carried out using a commercial CFD (computational fluid dynamics) simulation tool. The calculation results were used to get insight into improvement possibilities of the SF_6 gas flow model used in the software for computer simulation of HV (high-voltage) circuit breakers. Electric field calculation results were performed for the same 420 kV circuit breaker, in order to estimate the breakdown voltage at the current zero instant.  相似文献   

14.
In the last few decades, in the world and also in the European Union, considerable resources had been invested in the rapid development of renewable energy sources and distributed generation in general. At the same time, power consumption is continuously increasing, and consumers are becoming more complex, which ultimately requires new investments in the distribution network. Concept of smart grids is generally accepted as a possible solution. Smart grid is a concept with many elements, where monitoring and control of every element in the chain of production, transmission, distribution and final consumption enable much more efficient delivery and use of electricity. One of the elements of smart grid efficiency is the ability of real-time demand-supply balancing. This balancing is carried out by monitoring of consumption and redistribution of electricity among individual end users, according to their needs. The aim of this paper is creating algorithm for real-time load management using power measurements. Algorithm for real-time load management at the ETFOS (Faculty of Electrical Engineering in Osijek), Croatia is created based on measurements of photovoltaic power plant production, the power consumption of air conditioning system and the faculty building total electricity consumption. Expected result of real-time re-dispatching of air conditioners consumption, depending on the level of electricity production in photovoltaic power plant is decreasing peak demand of the faculty.  相似文献   

15.
Coal is still a major source of energy, also a major source of SO_2, NOx and CO_2 emission though. Removal of SO_2 and NOx doubled the cost of power generation, and capture of CO_2 is equivalent to double the market price of power coal. The GCP (green coal power) is the power generated in coal-combustion with zero emission. The author indicates that it is possible to make coal-fired power plants emission free based on thermodynamic analysis and purposely designed experiments using SFG (simulated flue gases). It is concluded in the study that all SO_2 and NOx in the post-combustion flue gas are reduced to inoffensive substances at temperature lower than 750 ℃ when contacting carbon and elemental sulfur is separated in succeeded cooling of flue gas at temperatures 200-400 ℃, and the ultrafine dusts are trapped in condensed water at temperature blow 100 ℃. Based on chemical engineering expertise the author is sure that the cost for removing acid gases is much lower than any clean coal technologies known to today. Instead of capture, the remained CO_2 is converted to CO in the second time contact with carbon at 900-950 ℃. CO is the raw material of chemical synthesis and, thus, CO_2 is stored in chemical products such as methanol, fertilizer, plastics, etc. The simple and low-cost processing allows GCP utilized in practice easily.  相似文献   

16.
This paper introduced the status quo of wind power and wind power generation technology. Focusing on the introduction of wind power generating system ibrational self-consistent field(VSCF), program implementation included Alternating Current (AC)-Direct Current (DC)-AC conversion system, magnetic field modulation generator system, doubly-fed generator system etc. Among these, doubly-fed generator system is the trend. Where to build the wind farm is very important, so a perfect site is needed. Wind power generation will have a bright future. As long as the wind power can be linked to the grid in large scale.  相似文献   

17.
Rate transient method is a recently-developed performance analysis tool specially designed for low-permeability or tight gas reservoirs. This method, theoretically based on pressure transient analysis, integrates material balance principle and the concept of material balance pseudo-time proposed by Blansingame. With daily production data of gas well, it could be used to calculate OGIP, current formation pressure, permeability, skin factor, to identify complex geologic boundaries, to determine whether drainage boundary has been reached, to calculate drainage area and drainage radius for single well and to predict performance. It has been extensively employed in more than ten low-permeability gas fields. It proves that most problems in performance analysis for low permeability gas reservoirs could be solved by this method. Field practices show great economical benefits could be achieved by employing this method in gas field development.  相似文献   

18.
In order to expand the natural energy and the energy conservation, "the smart PV (photovoltaic power generation) & EV (electric vehicle) system" has been proposed and the effect has been clarified. In the smart PV & EV system, it is important that electric vehicles become popular. Therefore, the AI-EV (air-conditioner integrated electric vehicle) has been proposed. In this paper, the AI-EV is designed based on the required car air-conditioner capacity. And, the value of AI-EV is compared with a gasoline vehicle, HV (hybrid vehicle) and EV using the mathematical simulation model As a result, it is clarified that the minimum displacement of the small-engine is 120 cc for AI-EV. In the smart PV & EV system, AI-EV can reduce CO_2 emissions by 20% almost the same as EV. Additionally, AI-EV is able to gain the cruising range more than twice as long as EV.  相似文献   

19.
Methane drainage is used in Polish coal mines in order to reduce mine methane emission as well as to keep methane concentration in mine workings at safe levels. This article describes the method of methane drainage used in longwall 2 in seam 506. In Poland, coal seams are frequently mined in difficult conditions of very high methane hazard. Under such situations, methane is drained by means of parallel ventilation headings. This paper shows the influence of a specific ventilation system on the drainage efficiency at longwall 2 in seam 506. At this longwall, measurements of methane emission and the efficiency of drained methane were conducted. They consisted in gauging methane concentration, air velocity, absolute air pressure and the amount of methane removed via a drainage system. Experimental data were used to estimate the variations in absolute methane-bearing capacity, ventilation air methane and most importantly, to gauge the efficiency of methane drainage.  相似文献   

20.
Metal/Air batteries are considered to be promising electricity storage devices given their compactness, environmental benignity and affordability. As a commonly available metal, aluminum has received great attention since its first use as an anode in a battery. Its high specific energy (even better volumetric energy density than lithium) makes it ideal for many primary battery applications. However, the development of A1/Air cell with alkaline electrolyte has been lagged behind mainly due to the unfavorable parasitic hydrogen generation. Herein, we designed and constructed a novel A1/H_2/Air tandem fuel cell to turn the adverse parasitic reaction into a useful process. The system consists of two anodes, namely, aluminum and hydrogen, and one common air-breathing cathode. The aluminum acts as both the anode for the A1/Air sub-cell and the source to generate hydrogen for the hydrogen/air sub-cell. The aluminum/air sub-cell has an open circuit voltage of 1.45 V and the H_2/Air sub-cell of 0.95 V. We demonstrated that the maximum power output of aluminum as a fuel was largely enhanced by 31% after incorporating the H_2/Air sub-cell with the tandem concept. In addition, a passive design was utilized in our tandem system to eliminate the dependence on auxiliary pumping sub-systems so that the whole system remained neat and eliminated the dependence of energy consuming pumps or heaters which were typically applied in micro fuel cells.  相似文献   

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