scholarly journals Development of Highly Efficient Radiation-Convective Recuperator for Furnace of Secondary Aluminum Melting

2021 ◽  
Author(s):  
Mykyta Vorobiov ◽  
Volodymyr Zgurskyi ◽  
Alexey Prokofiev ◽  
Ruslan Gubatyk
Keyword(s):  
High Efficiency ◽  
Aerodynamic Drag ◽  
Annular Channel ◽  
Combustion Products ◽  
Efficient Design ◽  
Cfd Modelling ◽  
Secondary Aluminum ◽  
Ring Channel ◽  
High Efficient ◽  
Peripheral Ring

The high efficient design of the radiation-convective recuperator with secondary emitters have been proposed, in which due to the rational arrangement of heating surfaces, as well as due to the installation of secondary emitters in flues, an increase in heat perception is transmitted to the secondary heat carrier – preheating air. High efficiency of air preheating is provided by two-stage heating: 1st stage of heating – the internal air ring channel with bilateral heating which is washed by combustion products from the parties of the central cylindrical and peripheral ring channels of combustion products; 2nd stage of heating – the external air ring channel in which unilateral heating by products of combustion from the peripheral ring channel of products of combustion is organized. Inner and outer annular air ducts (tanks), interconnected by bypass pipes. To increase the efficiency of heat transfer in the considered recuperator in the central channel of combustion products is placed emitter, which consisting of intersecting radial plates, and in the annular channel of combustion products are placed auxiliary emitters, which made in the form of flat radial edges. These emitters provide an increasing in total heat flux to the walls of the channels of the recuperator. On the basis of the conducted theoretical researches, engineering calculations and CFD – modelling the characteristics of operation of the recuperator for its installation on the furnace of secondary smelting of aluminium are defined. The main advantages of the new design of recuperator are high thermo-hydraulic efficiency, compactness and low metal consumption, ease of installation on the furnace and no need for placement in separate chimneys. It is established that the recuperator provides air heating ta,ex ~ 400 °C at an acceptable aerodynamic drag (pressure drop) on the air track (∆pa ~ 1000 Pa). Appropriate design documentation has been developed for the manufacture of the recuperator, which is installed on a pilot furnace of secondary aluminium smelting by California Die Casting (USA).

An Efficient Design for Interleaved Active Clamp Flyback Used in Grid-Connected Solar Microinverter

2015 ◽  
Vol 719-720 ◽  
pp. 640-643
Author(s):  
Yan Jin Hou ◽  
Ming Bai ◽  
Xin Yu Cui ◽  
Yan Cao
Keyword(s):  
Efficient Method ◽  
High Efficiency ◽  
Single Stage ◽  
Efficient Design ◽  
Flyback Converter ◽  
Pv Panel ◽  
High Efficient ◽  
Active Clamp

This document presents a high efficient method for interleaved active clamp flyback used in microinverter. The flyback converter was selected as a single stage topology that can boost the low PV panel voltages to a rectified AC output. How to handle the leakage energy for high efficiency and protecting the MOSFET ,how to calculate the parameter and choose the compenent also be showed in this document.

Recent Advances in Heterostructured Photocatalysts for Degradation of Organic Pollutants.

2020 ◽  
Vol 17 ◽  
Author(s):  
Chen-Jing Sun ◽  
Li-Ping Zhao ◽  
Rui Wang
Keyword(s):  
Organic Pollutants ◽  
High Efficiency ◽  
Separation Efficiency ◽  
Organic Pollution ◽  
Utilization Rate ◽  
Type I ◽  
Human Beings ◽  
Global Challenge ◽  
Global Environmental ◽  
High Efficient

: With the development of industrialization, the global environmental pollution and energy crisis are becoming increasingly serious. Organic pollutants pose a serious health threat to human beings and other organisms. The removal of organic pollutants in environment has become a global challenge. The photocatalytic technology has been widely used in the degradation of organic pollutants with its characteristics of simple process, high efficiency, thorough degradation and no secondary pollution. However, the single photocatalyst represented by TiO2 has disadvantages of low light utilization rate and high recombination rate of photocarriers. Building heterojunction is considered one of the most effective methods to enhance the photocatalytic performance of single photocatalyst, which can improve the separation efficiency of photocarriers and utilization of visible light. The classical heterojunction can be divided into four different cases: type I, typeⅡ, p–n heterojunctions and Z-scheme junction. In this paper, the recent progress in the treatment of organic pollution by heterostructure photocatalysts is summarized and the mechanism of heterostructure photocatalysts for the treatment of organic pollutants is reviewed. It is expected that this paper can deepen the understanding of heterostructure photocatalysts and provide guidance for high efficient photocatalytic degradation of organic pollutants in the future.

scholarly journals Friction-Induced Recycling Process for User-Specific Semi-Finished Product Production

Metals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 663
Author(s):  
Thomas Borgert ◽  
Werner Homberg
Keyword(s):  
High Efficiency ◽  
Research Work ◽  
Hot Extrusion ◽  
Extrusion Process ◽  
Efficient Production ◽  
Secondary Aluminum ◽  
Shape Accuracy ◽  
Aluminum Chips ◽  
Spinning Process ◽  
Complex Parts

Modern forming processes often allow today the efficient production of complex parts. In order to increase the sustainability of forming processes it would be favorable if the forming of workpieces becomes possible using production waste. At the Chair of Forming and Machining Technology of the Paderborn University (LUF) research is presently conducted with the overall goal to produce workpieces directly from secondary aluminum (e.g., powder and chips). Therefore, friction-based forming processes like friction spinning (or cognate processes) are used due to their high efficiency. As a pre-step, the production of semi-finished parts was the subject of accorded research work at the LUF. Therefore, a friction-based hot extrusion process was used for the full recycling or rework of aluminum chips into profiles. Investigations of the recycled semi-finished products show that they are comparable to conventionally produced semi-finished products in terms of dimensional stability and shape accuracy. An analysis of the mechanical properties of hardness and tensile strength shows that a final product with good and homogeneously distributed properties can be produced. Furthermore, significant correlations to the friction spinning process could be found that are useful for the above-mentioned direct part production from secondary aluminum.

scholarly journals Wireless Energy Transfer

2015 ◽  
pp. 63-91
Author(s):  
Aya Mabrouki ◽  
Mohamed Latrach
Keyword(s):  
Energy Transfer ◽  
Energy Harvesting ◽  
Low Power ◽  
High Efficiency ◽  
Microwave Energy ◽  
Wireless Energy Transfer ◽  
Design Considerations ◽  
High Efficient ◽  
Harvesting Techniques ◽  
Power Rectifier

This chapter proposes an overview of microwave energy harvesting with focuses on the design of high efficiency low power rectifying circuits. A background survey of RF energy harvesting techniques is presented first. Then, the performances of conventional rectifier topologies are analyzed and discussed. A review of the most efficient rectenna designs, from the state of the art, is also presented. Design considerations for low power rectifier operations are detailed and new high efficient rectifying circuits are designed and evaluated in both GSM and ISM bands under low power constraints.

scholarly journals Modeling of texture of the surface of collector plates

2019 ◽  
Vol 3 (122) ◽  
pp. 59-71
Author(s):  
Volodymyr Serhiiovych Hryshyn ◽  
Serhii Oleksiiovych Abramov
Keyword(s):  
High Efficiency ◽  
Statistical Simulation ◽  
Optimal Choice ◽  
Technological Parameters ◽  
Resource Saving ◽  
Technological Processes ◽  
Air Jet ◽  
Concrete Production ◽  
High Efficient ◽  
The Relationship

Technological possibilities of jet processing cause increased attention to the study of the regularities of the process. The main interest for practice is the establishment of the kind of dependencies between technological parameters (abrasive particles size, particle speed, concentration, compressed air pressure, attack angle, physical and mechanical properties of particles and surface to be treated) and initial process parameters (roughness of the treated surface, removal rates of the metal and libel). That, in turn, determines the necessity of optimal choice of the values of technological parameters in the conditions of a concrete production situation. The basic regularities can be established as a result of regression analysis of experimental data. However, the use of the resulting laws is limited to the complexity of the process and relatively narrow areas of changing the parameters of the experiment.The purpose of the work is to determine the factors that determine the formation of a microrelief in the area of the abrasive air jet, the relationship between them and the degree of their effect on the intensity of the formation of a microrelief; formation of a model of finishing treatment of collector plates, creation of theoretical bases and methodology of designing high-efficient resource-saving technological processes of production of motor collectors of electric machines.Analysis of recent research and publications. The following contributions were made to the development of the theory of modeling of the inkjet-abrasive surface treatment: Volovetsky O.E., Denysyuk V.Yu., Kharchik M.M., Buts BP, Andilahi A.A., Novikov FV, Gordeyev AI, Urbanyuk Ye.A., Silin R.S. and other.The most universal approach based on determining the search dependencies and solving the problem of optimizing the technological parameters of the processing process as a result of statistical simulation, namely the ability to control the input parameters before the start of the model or in the process of work - one of the key benefits of using simulation modeling for the analysis of systems and processes. This allows you to determine the optimal parameters, which maximize the efficiency of the processes, determine the relationship between the input and output parameters.The paper considers: creation of theoretical bases and methodology of designing high-efficiency resource-saving technological processes of production of motor collectors of electric machines; the process of formation of microrelief of collector plates in the area of the abrasive air jet, the relationship between the factors and the degree of their influence on the intensity of formation. The formation of a model of finishing treatment of collector plates treated with silicon carbide (black) was determined.Prospects for further research are the improvement of the technological process of obtaining collector nodes on the possibilities of implementation.

Investigation of a Variable Geometry Turbine Nozzle for Diesel Engine Turbochargers

2019 ◽  
Author(s):  
Anuj Srivastava ◽  
Kuldeep Kumar ◽  
Ganesh Banda
Keyword(s):  
Pressure Ratio ◽  
Boost Pressure ◽  
Variable Geometry ◽  
Efficient Design ◽  
Performance Variation ◽  
High Efficient ◽  
Emission Regulations ◽  
Variable Geometry Turbine ◽  
Potential Benefits ◽  
Wide Operating

Abstract High power demand, emission regulations, high efficient design are the prime requirement for the design of turbochargers. VGT (variable geometry turbocharging) is most widely used and explored compared to other available options to deal with today’s market. VGT turbochargers offers several potential benefits when compared to fixed geometry turbochargers, like increased transient response, wide operating range, improved torque characteristics, boost pressure recovery and better fuel economy. In this paper performance variation of compressor and turbine viz, — Pressure ratio, mass flow, and efficiency, and throat area are optimized to reach to the operating point of the engine. Different vane angles (0, +4°, +7°, +10° & +15°) are studied to understand the variation of transient turbine response. Authors also discussed the mechanical conceptualization of the VANT (Variable area nozzle) in thought of having great impact on the performance.

Valveless-Gas-Turbine Combustors With Pressure Gain

1958 ◽  
Author(s):  
Carroll D. Porter
Keyword(s):  
Steady Flow ◽  
Gas Turbine ◽  
Total Pressure ◽  
High Efficiency ◽  
Combustion Products ◽  
Efficiency Gain ◽  
Developmental Problems ◽  
Gas Turbine Combustors ◽  
Turbine Inlet ◽  
Gas Turbine Compressor

A valveless combustor has been developed which has been tested at one to three atmospheres of pressure. It discharged combustion products at practical turbine-inlet temperatures and at a total pressure above that of the inlet. Developmental problems encountered and results are discussed. The smooth combustor cycle, a phased system of combustor tubes and pulsation traps, achieves steady flow at the inlet and outlet of the combustor system to preserve the high efficiency of today’s turbines and compressors. The combustor will soon be tested on a gas-turbine compressor to verify efficiency gain estimates.

scholarly journals Effect of NS-DBD Actuator Parameters on the Aerodynamic Performance of a Flap Lifting Device

2019 ◽  
Vol 9 (23) ◽  
pp. 5213 ◽  
Author(s):  
Kun Chen ◽  
Chen-Yao Wei ◽  
Zhi-Wei Shi
Keyword(s):  
Energy Density ◽  
Flow Field ◽  
Drag Reduction ◽  
Pulse Width ◽  
High Efficiency ◽  
Aerodynamic Drag ◽  
Pulse Discharge ◽  
Excitation Frequency ◽  
Aerodynamic Performance ◽  
Discharge Pulse

The flap lift device is an important part of the conventional configuration of aircrafts and has an important impact on the aerodynamic performance. In this paper, a high-efficiency, simple, and energy-saving nanosecond dielectric barrier discharge (DBD) plasma actuator is placed in the vicinity of the flap lift device to improve the aerodynamic performance of the flap by controlling the flow field. The two-dimensional airfoil GAW-1 and its 29% flap were selected as the research objects, and the nanosecond (NS) DBD actuators were fixed at different locations near the deflection angle of the 10°flap. The excitation frequency, pulse width, and energy density parameters of the pulse discharge were adjusted, and then, the effects of parameter changes on aerodynamic characteristics of the airfoil were studied by numerical simulation. The simulation results show that adjusting the excitation frequency on the aerodynamic drag is weak and that the effect on the aerodynamic lift is obvious. The increase of the discharge pulse width will have a more significant effect on the flow field, i.e., a proper increase of the discharge pulse width can achieve better drag reduction, and increase lift after a stall at a high angle of attack. Although the increase of discharge energy density can strengthen the pulse perturbation effect on the flow field, it also contributes to some adverse effects and has no obvious optimization effect on the control efficiency of lift increase and drag reduction.

A MODIFIED VAN DER PAUW SETUP FOR MEASURING THE RESISTIVITY AND THERMOPOWER OF THERMOELECTRIC MATERIALS OF VARYING THICKNESSES

2013 ◽  
Vol 06 (05) ◽  
pp. 1340009 ◽  
Author(s):  
DALE HITCHCOCK ◽  
SPENCER WALDROP ◽  
JARED WILLIAMS ◽  
TERRY M. TRITT
Keyword(s):  
Thermoelectric Materials ◽  
Room Temperature ◽  
High Efficiency ◽  
Vast Number ◽  
Efficiency Optimization ◽  
Resistivity Measurements ◽  
High Efficient ◽  
Van Der Pauw ◽  
Binary Compounds ◽  
New Compounds

In the investigation of thermoelectric (TE) materials as a practical, and efficient, means of power generation/ refrigeration nearly ninety percent of the possible high-efficient binary compounds have been evaluated. But only a few proved to be useful such as Bi 2 Te 3 alloys, PbTe and SiGe to name the most important materials. Therefore, in order to expand the research of high-efficiency TE materials new compounds and methods of efficiency optimization must be explored. There currently exist a vast number of uninvestigated ternary and quaternary materials that could be potential high-efficiency thermoelectric materials. The device and methodology discussed herein deal with rapidly measuring both the electrical resistivity and the Seebeck coefficient of thermoelectric materials, at a set temperature of T ≈ 300 K. Using nontraditional resistivity measurements and rapid, room-temperature thermopower measurements, a reliable and time-efficient means of gauging the power factor (defined below) values of newly synthesized thermoelectric materials is achievable. Furthermore, the efficacy of the van der Pauw technique for measuring the resistivity of thermoelectric materials has been verified.

The Gas Turbine Family GT13E and GT13E2 Provides Reliable Power for Asia

1996 ◽  
Author(s):  
Gregor Gnädig
Keyword(s):  
Power Generation ◽  
Gas Turbines ◽  
Power Plants ◽  
High Efficiency ◽  
Operating Experience ◽  
Diesel Oil ◽  
Combined Cycle ◽  
Asian Countries ◽  
High Efficient ◽  
Prime Movers

Many Asian countries are experiencing economic growth which averages 5–10% per year. This environment has led to a privatization process in the power generation industry from typically state-run utilities to a system in which a federal agency oversees a market divided by private utilities and independent power producers (IPP) with the need for high efficiency, reliable power generation running on natural gas and diesel oil. In the 50 Hz market, modem, high efficient gas turbines of the type GT13E and GT13E2 have been chosen as prime movers in many combined cycle power plants in Asian countries. This paper includes a product description, and a general overview of GT13E and GT13E2 operating experience, well as an economic evaluation of a typical 500 MW combined cycle power plant.

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