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1.
In this study, the authors have shown the power conversion efficiency of flexible organic solar cells. The structure of the device is PET/ITO/PEDOT: PSS/P3HT: PCBM/AI. P3HT (poly-3-hexylthiophene). It was used as an electron donor, PCBM ([6, 6]-phenyl C6 l-butyric acid methyl ester) as an electron acceptor and PEDOT: PSS used as a HIL (hole injection layer). These materials were deposited by spin coating method on the flexible substrates. Photolithography method is used to etch ITO. The electrical parameters of the fabricated cells were investigated by means of J (V), FF (fill factor), the efficiency (r/), photocurrent and IPCE measurement. It was observed that 45% of the absorbed photons are converted into current. The results obtained using etching technology by photolithography is better than that obtained in the clean room.  相似文献   

2.
Transformers are normally designed and built for use at rated frequency and sinusoidal load current. A non-linear load on a transformer leads to harmonic power losses which cause increased operational costs and additional heating in transformer parts. It leads to higher losses, early fatigue of insulation, premature failure and reduction of the useful life of the transformer. To prevent these problems, the rated capacity of transformer which supplies harmonic loads must be reduced. In this work, a typical 50 kVA three-phase distribution transformer with real practical parameters is taken under non-linear loads generated due to domestic loads. The core losses is evaluated using the three dimensional model of the transformer developed in FEM (finite element method) program based on valid model of transformer under high harmonic conditions. And finally a relation associated with core losses and amplitude of high harmonic order are reviewed & analyzed and then a comparison is being carried out on the results obtained by different excitation current in transformer windings.  相似文献   

3.
The flow field of 3D (three-dimensional) wall-jet is investigated. Jet-blast from airplane is simulated by wall-jet setup using a sonic nozzle at a laboratory scale. Farfield velocity and fluctuation distributions are measured by using X-type hot wire anemometer at four measurement planes. As a result, the flow properties of streamwise component are consistent with data which are obtained in previous researches. The secondary flow is also measured on each measurement plane. Reynolds stresses, v'v' and w' w', are analyzed from the fluctuation of the secondary flow. The law of similarity is observed in the dimensionless distributions of mean velocity and fluctuation. However, the distributions in nearer field (i.e., in the measurement plane at X/D = 100) tend to disobey the similarity law, especially in the cases of fluctuation. It seems that jet-blast is not fully developed by reaching X/D = 100. The experimental results are compared with computational results which are obtained by CFD (computational fluid dynamics) with SST (shear-stress transport) turbulence model. And it is shown that the results by the simulation with SST turbulence model do not follow the similarity law. The present database of the Reynolds stresses is critically important for development of a new turbulence model of RANS (reynolds-averaged navier-atokes) simulations on wall-jet.  相似文献   

4.
The KHNP (Korea Hydro & Nuclear Power Co.) has developed a multipurpose nuclear safety analysis code called SPACE (the safety and performance analysis code) for nuclear power plants. SPACE code is a best-estimated two-phase three-field thermal-hydraulic analysis code used to analyze the safety and performance of pressurized water reactors. In this paper, LOFT (loss of fluid test) L9-3 experiment using the SPACE code was selected to confirm the capability of SPACE code and the results calculated by the SPACE code are compared with those measured through the experiment. The results were compared with the experimental data and those of the other code simulations. Throughout the simulation result, it was concluded that the SPACE code can effectively simulate LOFT L9-3 experiment.  相似文献   

5.
A comparative analysis of the properties of LiNi0.5Mn0.5O2 and Li1+xNi0.5Mn0.5O2 (0.2 ≤ x ≤ 0.7) powders, obtained by the freeze drying method, was performed. Lattice parameters of Li1+xNi0.5Mn0.5O2 decreased considerably with growing amounts of Li until x = 0.3; at x > 0.5 trace amounts of Li2MnO3 are observed by X-ray diffraction (XRD) patterns. X-ray photoelectron spectroscopy (XPS) analysis displayed an increase of Ni3+/Ni2+ ratio at 0.3 < x < 0.5, while Mn 2p spectra were almost identical in all samples. Rechargeable capacity values (V = 2.5–4.6 V) increased systematically with x reaching its maximum (185–190 mAh g−1) at x = 0.5. Samples with superstoichiometric lithium content also demonstrated good C rate characteristics.  相似文献   

6.
The “uphill” diffusion of hydrogen during permeation through flat sheets of palladium and nickel has been studied by an electrochemical permeation method at 303 K. For both annealed and “as cold rolled” Pd samples, uphill diffusion effects on hydrogen absorption and desorption have been observed over a range of initial hydrogen contents from about H/Pd = 0.01, i.e. near or slightly less than the max composition, up to H/Pd = 0.25–0.3. The occurrence of a non-Fickian component of permeation flux has been associated with temporary formation of lattice volume differences across the ( + β)/β and ( + β)/ interfaces during absorptions and desorptions, respectively. Influences of the magnitudes of galvanostatic hydrogen fluxes and of the membrane thickness on the uphill effects were examined. Analogous uphill effects were observed in similar studies with nickel membranes also in both annealed and “as cold rolled” states, which were much larger than those observed for palladium.  相似文献   

7.
The purpose of given article-consideration of the basic features of modern manufacturing of nuclear fuel which would confirm fact, that the manufacturer does everything that its production would respond not only to requirements of the consumer, but also to its expected inquiries, and would correspond to intended purposes of fuel. It was defined main tendencies and features of modern technology, especially in nuclear fuel production, on base of meeting discussions, themes of journal articles on nuclear subject. They are correspond with practice of JSC NCCP (Novosibirsk Chemical Concentrates Plant) and listed in the paper. In result of it number of base features of any advanced technology, not only nuclear, described here with examples from NCCP's practice. Of course, there is no certain list of all attributes of modern manufacturing as there is no limit to its perfection. These categories are forming by current needs of the market, but listed ones must be.  相似文献   

8.
Power quality is one of the major concerns among consumers and electric utility companies. CUPS (custom power systems) devices are used to improve the quality of power and enhance the reliability of the power supply in the distribution networks. The DVR (dynamic voltage restorer) is an important CUPS device used to mitigate voltage sag/swell and imbalances. Various control techniques have been implemented to control the DVR, among which the PID (proportional-integral-derivative) controller is dominant because of its model independent property and its error driven technique. In this paper, a new controller based on the ADRC (active disturbance rejection control) concept is developed, and its performance is compared to that of the PID controller. The model of the DVR and its ADRC and PID controllers were developed under the MATLAB (matrix laboratory)/Simulink environment. The simulation results demonstrated the effectiveness of the ADRC over the PID controller.  相似文献   

9.
This paper deals with an integration of directly measured electrical parameters with data acquired by data communication from protections and terminals into an advanced monitoring system. Based on the periodic test, the authors of this paper present the possibility of an extended evaluation and more accurate analysis of transient and failure events. For periodical testing, as implemented during the commissioning of power plants in the Czech Republic, a monitoring system of electrical equipment has been used, to record the courses of important electrical parameters and thus, proving the proper functioning of complex technological systems in various operation modes. Data from monitoring system were used to prove the successful results of the test or as a base data for further analysis of failures. The monitoring system has proved itself as a very useful device also when recording unexpected failure events, the cause of which was very quickly and accurately detected by the follow-up analysis. Initially, only the voltage and current data from measuring transformers, analogue transducers and contact relays were used as input data for the monitoring system. After the implementation of new digital protection technology and controlling terminals with inner data recorder, the data from digital devices could be also utilized for the monitoring system.  相似文献   

10.
Power systems are the largest and most complex human made systems, consisting of thousands of electrical sources, loads, transmission and distribution lines, power transformers, circuit breakers, etc. where faults always occurred. Faults can cause personnel and equipment safety problems, and can result in significant disruption to power supply and thus financial losses. In this paper we will present comprehensive mathematical suite to detect and classify fault dependent models of various types of power systems. This work will extract fault unique signatures by using polarization ellipse during the healthy condition and the polarization will be circular shape with radius equal the rated voltage of the system, but during the fault condition the polarization will be ellipse shape and the fault signature will be defined according the ellipse parameters major axis, minor axis, ellipticity and orientation angle, by using least squares criterion will define the ellipse parameters this system will identify and classify. This paper will be a milestone for extended paper based on the proposed mathematical modelling and applying it to identify, classify and localize with simulation model.  相似文献   

11.
This work concerns the study of HSs (Hybrid Systems) that are made up of the integration of M-HTFC (Medium and High Temperature Fuel Cell) and MGT (Micro-Gas-Turbine). Different typologies of hybrid systems are taken into account, which differ from each other in their plant layouts. The plants are considered in cogenerative arrangement. The aim of this study is to carry out an energetic analysis of the HS considered to obtain an analytical expression to depict the system operating in cogenerative arrangement. An energetic comparison among the systems analyzed based on some indexes is effected, which allows an evaluation of the plants performances in cogenerative arrangement. An energetic analysis is carried out, which is based on a "black box" depiction of the plant in which the components and the mutual interactions are highlighted. The fuel cell component of the plant is not analyzed as a black box, but each element that constitutes it, is elaborated as a subsystem.  相似文献   

12.
This paper is concerned with the fossil fuel composition of carbon emissions in 10 selected Asian countries. It assesses how economic development may affect this composition through various channels. This paper contributes to the debate on the EKC (environmental Kuznets curve) puzzle, which hypothesizes an inverted U-shaped relationship between per capita income and pollution. The paper examines the EKC hypothesis in an empirical analysis of channels that may allow for this effect. In particular, a specific subset of this general paradigm is investigated using a fractional multinomial logit model to assess how indicators associated with economic development and energy prices affect carbon emissions from coal relative to those of natural gas and oil.  相似文献   

13.
The use of the Albanian geothermal springs and waters, for their curative effects (Natural SPA) dates back centuries, since the time of the Roman Empire, while their first modern use started only in 1937. Unfortunately they had not been used for its energetic values yet. The temperature of the water is above 60 ~C and the flow above 16 L/s, thus direct utilization is possible, in particular for space heating. Three-dimensional temperature field calculations and engineering calculations on a heating system with heat exchangers are presented here. The results show that the water temperature is expected to be stable and considerably higher temperature is expected through deep well drilling. The University's Campus of Tirana is composed of 29 buildings, which are partially heated through a coal heater. The installed capacity is 2,558 kW while the coal consumption is about 920 kg/h. The University's Campus of Tirana is one of the most important areas and with the highest density of population in Tirana, so it is the best area to show the heat exchanger efficiency. The economic analyses prove that the borehole heat exchangers are more convenient than the coal heating systems.  相似文献   

14.
The authors have proposed that a counter-rotating type tidal stream power unit mounted rigidly on a pile, and outputs of the power unit and forces acting on the pile were investigated experimentally at a previous paper, A single propeller makes the pile undertake a reaction force orthogonal to the stream direction. On the contrary, proposed counter-rotating propellers do not require undertaking the reaction force of the pile, because the rotational torque is counter-balanced in the unit. This advantage means that the unit can be moored by only one cable. Continuously, this paper proposes such a power unit with tandem propellers, and experimentally investigates a behavior of the unit floating in a water channel. The vibrations of the power unit are induced from not only the individual but also the interacting rotations of the front and the rear propellers.  相似文献   

15.
The study of nano properties of PbSe (lead selenide) thin films deposited on TiO2 semi conductor film prepared by sol gel method was a new work destined to perfect the nano materials used in photovoltaic energy. The growth of the first group of the fihns (Set 1: P(9)) & P(14)) was based on the decomposition of lead citrate and sodium selenosulphite in the presence of sodium citrate and sodium hydroxide with ammonia and triethalamine (TEA) acting as the complexing agents and P.H stabilizers; while in the second group (Set 2: Pc15~), the reaction bath was made up of solutions of lead nitrate Pb(NO3)2, PVA (polyvinyl alcohol), H20 (distilled water), NH3 (ammonia), sodium selenosulphite (Na2SeSO3) and Triethalamine [N(CH2CH2OH)], which was used as the complexing agent. The deposited materials were identified by X-ray diffraction. In addition, nano optical and morphological investigations were also performed. The sample P9 has the lowest absorbance of about 0.3 nm in the ultra-violet region. It was found that there was a reduction in the optical absorbance as the wavelength increases. The optical band gap shows a range of 1.26-2.00 eV with sample PcIs~ having the lowest direct band gap.  相似文献   

16.
This paper focuses on a comparison of experimental and numerical investigations performed on a low-pressure mid-loaded turbine blade at operating conditions comprised of a wide range of Mach numbers(from 0.5-1.1),Reynolds numbers(from 0.4e+5-3.0e+5),flow incidence(-15-15 degrees) and three levels of free-stream turbulence intensities(2,5 and 10%).The experimental part of the work was performed in a high-speed linear cascade wind tunnel.The increased levels of turbulence were achieved by a passive grid placed at the cascade inlet.A two-dimensional flow field at the center of the blade was traversed pitch-wise upstream and downstream the cascade by means of a five-hole probe and a needle pressure probe,respectively.The blade loading was measured using the surface pressure taps evenly deployed at the blade mid-span along the suction and the pressure side.The inlet turbulence was investigated using the constant temperature anemometer technique with a dual sensor probe.Experimentally evaluated values of turbulent kinetic energy and its dissipation rate were then used as inputs for the numerical simulations.An in-house code based on a system of the Favre-averaged Navier-Stokes equation closed by a two-equation k-turbulence model was adopted for the predictions.The code utilizes an algebraic model of bypass transition valid both for attached as for separated flows taking in account the effect of free-stream turbulence and pressure gradient.The resulting comparison was carried out in terms of the kinetic energy loss coefficient,distributions of downstream wakes and blade velocity.Additionally a flow visualization was performed by means of the Schlieren technique in order to provide a further understanding of the studied phenomena.A few selected cases with a particular interest in the attached and separated flow transition are compared and discussed.  相似文献   

17.
This serial research has proposed the hybrid power system combined the wind power unit with the counter-rotating type pump-turbine unit, to provide the constant output for the grid system, even at the suddenly fluctuating/turbulent wind circumstance. In this paper, the tandem impellers prepared for the counter-rotating type pumping unit were operated at the turbine mode, and the performances and the flow conditions were investigated numerically with accompanying the experimental results. Even though providing the pumping unit for the turbine mode, the maximum hydraulic efficiency is close to one of the counter-rotating type hydroelectric unit designed exclusively for the turbine mode. Besides, the runners/impellers of the unit work evidently so as to coincide the angular momentum change through the front runners/impellers with that through the rear runners/impellers, namely to take the axial flow at not only the inlet but also the outlet, without the guide vanes. From these results, it can be concluded that this type unit is effective to work at not only the pumping but also the turbine modes.  相似文献   

18.
19.
A numerical study has been carried out to investigate heat transfer by free convection under the effect of MHD (magnetohydrodynamic) for steady state three-dimensional laminar flow in horizontal and vertical cylindrical annulus filled with saturated porous media (sand silica) with fins attached to the inner cylinder. A single electric coil placed around the inner cylinder to generate a magnetic field. The governing equations which used are continuity, momentum (using Darcy's law) and energy equations which are transformed to dimensionless equations. The finite difference approach is used to obtain all the computational results using Fortran 90 program. The parameters affected on the system are Rayleigh number ranging within (102 ~ Ra* 〈 104), and MHD (Mn) (0 〈_ Mn 〈_ 100) and radius ratio Rr (0.225, 0.338 and 0.435). The results obtained are presented graphically in the form of streamline and isotherm contour plots and the results show that heat transfer decrease with the increase of magnetohydrodynamic. It was found that the average Nusselt number increase with Ra* and decrease with H~ Mn and Rr. A correlation for the average Nusselt number in terms of Ra* and Mn, has been developed for the inner cylinder.  相似文献   

20.
This paper introduces a powerful design and analysis tool named SIMCAT, that is developed to support applications to license a CANDU nuclear reactor, refurbish projects, and support the existing CANDU stations. It consists of the CATHENA (Canadian Algorithm for Thermo-Hydraulic Network Analysis), the control logics from C6SIM (CANDU 6 Analytical Simulator), and a communication protocol, PVM (parallel virtual machine). This is the first time that CATHENA has been successfully coupled directly with a program written in another language. The independence of CATHENA and the C6SIM controllers allows the development of both CATHENA and C6SIM controller to proceed independently.  相似文献   

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