Design Optimization of Moving Magnet Actuated Valves for Digital Displacement Machines

2017 ◽  
Author(s):  
Esben L. Madsen ◽  
Janus M. T. Jørgensen ◽  
Christian Nørgård ◽  
Michael Møller Bech
Keyword(s):  
High Efficiency ◽  
Electrical Power ◽  
Optimized Design ◽  
Closing Time ◽  
Valve Design ◽  
Single Coil ◽  
Hydraulic Machines ◽  
Electrical Power Consumption ◽  
Great Focus ◽  
Moving Magnet

High-efficiency hydraulic machines using digital valves are presently a topic of great focus. Digital valve performance with respect to pressure loss, closing time as well as electrical power consumption, is key to obtaining high efficiency. A recent digital seat valve design developed at Aalborg University utilizing moving coil actuation, meets these performance demands but is challenged by practical issues. This paper builds upon that design by proposing a retrofit which preserves both the seat valve topology and the outer dimensions, but utilizes moving magnet actuation. Through constrained multi-objective optimization, six initial topologies and three derived topologies, including designs with one, two and four coils, are optimized with respect to overall efficiency. Apart from the actuator, the flow forces on the seat valve geometry is modeled using CFD and included in optimization. In simulation the final optimized design closes in 2.1 ms, has a pressure drop of 0.8 bar at 150 l/min and yields a digital displacement machine average chamber efficiency of 98.9%. The design is simple in construction and uses a single coil, positioned outside the pressure chamber, eliminating the need for an electrical interface to the pressurized valve chamber.

Enzyme-assisted pulp refining: an energy saving approach

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Amit Kumar ◽  
Chhotu Ram ◽  
Adebabay Tazeb
Keyword(s):  
Energy Consumption ◽  
Paper Industry ◽  
Electrical Power ◽  
Manufacturing Cost ◽  
Paper Properties ◽  
Paper Making ◽  
Paper Manufacturing ◽  
Cost Of Energy ◽  
Refining Time ◽  
Electrical Power Consumption

AbstractEnergy conservation has become an essential step in pulp and paper industry due to diminishing fossil reserves and high cost of energy. Refining is a mechanical treatment of pulp that modifies the structure of the fibres in order to achieve desired paper-making properties. However, it consumes considerable amount of energy. The electrical power consumption has a direct impact on paper manufacturing cost. Therefore, there is a requirement to minimize the energy cost. Enzyme-assisted refining is the environment friendly option that reduces the energy consumption for papermaking. Enzyme-assisted refining is defined as mechanical refining after pretreatment of pulp with enzymes such as cellulases and hemicellulases. It not only reduces the energy consumption but also improves the quality of finished paper. Enzymes improve the beatability of pulp at same refining degree (°SR) and desired paper properties can be achieved at decreased refining time. The selection of suitable enzyme, optimization of enzyme dose and appropriate reaction time are the key factors for energy reduction and pulp quality improvement during enzyme-assisted refining.

scholarly journals Near-field thermophotovoltaics for efficient heat to electricity conversion at high power density

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Rohith Mittapally ◽  
Byungjun Lee ◽  
Linxiao Zhu ◽  
Amin Reihani ◽  
Ju Won Lim ◽  
...  
Keyword(s):  
Power Density ◽  
High Power ◽  
High Efficiency ◽  
Near Field ◽  
Electrical Power ◽  
Photovoltaic Cells ◽  
High Power Density ◽  
Pv Cell ◽  
Electrical Power Output ◽  
Power Densities

AbstractThermophotovoltaic approaches that take advantage of near-field evanescent modes are being actively explored due to their potential for high-power density and high-efficiency energy conversion. However, progress towards functional near-field thermophotovoltaic devices has been limited by challenges in creating thermally robust planar emitters and photovoltaic cells designed for near-field thermal radiation. Here, we demonstrate record power densities of ~5 kW/m2 at an efficiency of 6.8%, where the efficiency of the system is defined as the ratio of the electrical power output of the PV cell to the radiative heat transfer from the emitter to the PV cell. This was accomplished by developing novel emitter devices that can sustain temperatures as high as 1270 K and positioning them into the near-field (<100 nm) of custom-fabricated InGaAs-based thin film photovoltaic cells. In addition to demonstrating efficient heat-to-electricity conversion at high power density, we report the performance of thermophotovoltaic devices across a range of emitter temperatures (~800 K–1270 K) and gap sizes (70 nm–7 µm). The methods and insights achieved in this work represent a critical step towards understanding the fundamental principles of harvesting thermal energy in the near-field.

scholarly journals Research on the Spatio-Temporal Dynamic Evolution Characteristics and Influencing Factors of Electrical Power Consumption in Three Urban Agglomerations of Yangtze River Economic Belt, China Based on DMSP/OLS Night Light Data

2021 ◽  
Vol 13 (6) ◽  
pp. 1150
Author(s):  
Yang Zhong ◽  
Aiwen Lin ◽  
Chiwei Xiao ◽  
Zhigao Zhou
Keyword(s):  
Influencing Factors ◽  
Yangtze River ◽  
Electrical Power ◽  
Random Forest Algorithm ◽  
Temporal Dynamic ◽  
Urban Agglomerations ◽  
Evolution Characteristics ◽  
Spatio Temporal ◽  
Electrical Power Consumption ◽  
Gwr Model

In this paper, based on electrical power consumption (EPC) data extracted from DMSP/OLS night light data, we select three national-level urban agglomerations in China’s Yangtze River Economic Belt(YREB), includes Yangtze River Delta urban agglomerations(YRDUA), urban agglomeration in the middle reaches of the Yangtze River(UAMRYR), and Chengdu-Chongqing urban agglomeration(CCUA) as the research objects. In addition, the coefficient of variation (CV), kernel density analysis, cold hot spot analysis, trend analysis, standard deviation ellipse and Moran’s I Index were used to analyze the Spatio-temporal Dynamic Evolution Characteristics of EPC in the three urban agglomerations of the YREB. In addition, we also use geographically weighted regression (GWR) model and random forest algorithm to analyze the influencing factors of EPC in the three major urban agglomerations in YREB. The results of this study show that from 1992 to 2013, the CV of the EPC in the three urban agglomerations of YREB has been declining at the overall level. At the same time, the highest EPC value is in YRDUA, followed by UAMRYR and CCUA. In addition, with the increase of time, the high-value areas of EPC hot spots are basically distributed in YRDUA. The standard deviation ellipses of the EPC of the three urban agglomerations of YREB clearly show the characteristics of “east-west” spatial distribution. With the increase of time, the correlations and the agglomeration of the EPC in the three urban agglomerations of the YREB were both become more and more obvious. In terms of influencing factor analysis, by using GWR model, we found that the five influencing factors we selected basically have a positive impact on the EPC of the YREB. By using the Random forest algorithm, we found that the three main influencing factors of EPC in the three major urban agglomerations in the YREB are the proportion of secondary industry in GDP, Per capita disposable income of urban residents, and Urbanization rate.

Compact high-efficiency linear cryocooler in single-piston moving magnet design for HOT detectors

2012 ◽  
Author(s):  
I. Rühlich ◽  
M. Mai ◽  
C. Rosenhagen ◽  
A. Withopf ◽  
S. Zehner
Keyword(s):  
High Efficiency ◽  
Magnet Design ◽  
Hot Detectors ◽  
Moving Magnet

scholarly journals DIGITALIZATION OF THE ELECTRIC POWER METERING SYSTEM

2020 ◽  
pp. 74-83
Author(s):  
Ayrat G. Ziganshin ◽  
Georgi M. Mikheev
Keyword(s):  
Electric Power ◽  
Electrical Power ◽  
Electrical Energy ◽  
Smart Devices ◽  
Electrical Networks ◽  
Federal Law ◽  
Useful Power ◽  
The Republic ◽  
Power Metering ◽  
Electrical Power Consumption

The article deals with the issue of paying for electricity transmission services by consumers in connection with the introducing on the 1st of July, 2020 the Federal Law no. 522-FZ dated December 27, 2018 and the requirements for smart devices and electricity metering systems. This topic is one of the key points in the fight against non-payments for electrical energy, reducing business losses. The article draws attention to the change in the relationship between a consumer of electrical power and its supplier after the introduction of the above-mentioned law. The opportunities of intelligent electricity metering systems are examined as well as their features and some of their characteristics are given. On the example of the Verkhneuslonsky region of the Republic of Tatarstan, served by the branch of JSC “Network Company” Buinsky electrical networks, a comparative analysis of electrical power consumption is presented according to the data of those consumers who have smart metering devices installed and those who use ordinary counters. It is shown that installation of intelligent electric power metering systems made it possible to increase the useful power supply for the observed period by 15.5% in 2020 against 1.8% when using traditional counters for the same period of 2019.

scholarly journals Application of Latitude Stripe Division in Satellite Constellation Coverage to Ground

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Maocai Wang ◽  
Xin Luo ◽  
Guangming Dai ◽  
Xiaoyu Chen
Keyword(s):  
Orbital Period ◽  
High Efficiency ◽  
Classical Method ◽  
Grid Point ◽  
Spherical Geometry ◽  
Optimized Design ◽  
Target Region ◽  
Satellite Constellation ◽  
Orbital Periods ◽  
The Relationship

Grid point technique is a classical method in computing satellite constellation coverage to the ground regions. Aiming at improving the low computational efficiency of the conventional method, a method using latitude stripe division is proposed, which has high efficiency, and we name it latitude stripe method. After dividing the target region into several latitude stripes, the coverage status of each latitude stripe is computed by means of the spherical geometry relationship in the first orbital period. The longitude coverage intervals in the remaining orbital periods are computed by sliding the coverage status in the first orbital period. Based on this method, the instantaneous and cumulative coverage in simulation time can be calculated more efficiently. As well, the relationship between the cumulative coverage and altitude can be computed fast by this method, which could be used in the optimized design of repeating sun-synchronous orbits. The comparison between the conventional grid point method and the latitude stripe method shows that the latitude stripe method has high efficiency and accuracy. Through various case studies, the optimization in repeating sun-synchronous orbits design is successfully represented.

Design and Implementation of Z-Source Inverter by Simple Boost Control Technique for Laboratory Scale Micro-Hydro Power Plant Application

2021 ◽  
Vol 13 (2) ◽  
pp. 62-70
Author(s):  
Rizki Mendung Ariefianto ◽  
Rizky Ajie Aprilianto ◽  
Heri Suryoatmojo ◽  
Suwito Suwito
Keyword(s):  
Power Plant ◽  
High Efficiency ◽  
Electrical Power ◽  
Harmonic Distortion ◽  
Laboratory Scale ◽  
Control Technique ◽  
Induction Generator ◽  
Duty Ratio ◽  
Hydro Power ◽  
Boost Control

In a power plant such as micro-hydropower (MHP), an induction generator (IG) is usually employed to produce electrical power. Therefore, an inverter is needed to deliver it with high efficiency. Z-source inverter (ZSI) has been introduced as a topology with many advantages over conventional inverters. This research aims to investigate the performance of ZSI based simple boost control (SBC) in laboratory-scale MHP systems using a rewinding induction generator. This research has been conducted both from simulations and experiments. Based on the result, the waveform characteristic and value of ZSI are close to the desired design. A shoot-through duty ratio of 17% can reach 60 Vrms output voltage, and this condition has a conversion ratio of about 2.05 times. Also, SBC can significantly reduce the Total Harmonic Distortion (THD). ZSI efficiency has a value of 84.78% at 50% of rating load 100 W and an average value of 80%. Compared to the previous study, the proposed design has more economical with the same component for the higher rating power. Moreover, it has a smoother and entire output waveform of the voltage.

Design Rules for Low Electrical Power Consumption in Nonlinear Silicon Waveguides with Active Carrier Removal

2021 ◽  
Author(s):  
Valerio Vitali ◽  
Hao Liu ◽  
Iosif Demirtzioglou ◽  
Cosimo Lacava ◽  
Kyle R. H. Bottrill ◽  
...  
Keyword(s):  
Power Consumption ◽  
Electrical Power ◽  
Design Rules ◽  
Silicon Waveguides ◽  
Electrical Power Consumption
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