scholarly journals Induction motors with YY/D connection change for efficiency and power factor increasing at partial loads

2006 ◽  
Vol 19 (1) ◽  
pp. 85-98 ◽  
Author(s):  
Miloje Kostic ◽  
Jovan Radakovic
Keyword(s):  
Energy Efficiency ◽  
Energy Saving ◽  
Power Factor ◽  
Energy Savings ◽  
Induction Motors ◽  
Mean Value ◽  
The One ◽  
Partial Loads ◽  
Selection Of ◽  
Better Than

It is established that there exists a significant possibility for energy savings, on the basis of application of induction motors with YY/D connection change proposed in this paper, especially for power to 30 kW. In connection D (0.866Un), total losses and reactive loads are reduced to loads up to 75-85%. Benefits of such motors would be significant because more than 80% induction motors are light loaded (mean value ? 70%). In such manner one motor with two characteristics is attained, but that is better than to offer to the market two different motors, because only in exploitation it is possible to accurately select the one which is working with greater efficiency values in given conditions. However, at the motor with YY/D winding it is always possible, by selection of corresponding connection for (mean value) load measured in operation. Even, with connection change it is possible to adjust to load changes in future. Moreover, at loads ? 30%, energy saving by induction motors with YY/D connection is greater than the one using induction motors with thyristor controllers. Induction motors YY/D connection application may be economical in cases where it is not recommended to use higher costs of energy efficiency of motors.

Subjective Time Preference and Willingness to Pay for an Energy-Saving Durable Good

2001 ◽  
Vol 32 (3) ◽  
pp. 133-141 ◽  
Author(s):  
Gerrit Antonides ◽  
Sophia R. Wunderink
Keyword(s):  
Willingness To Pay ◽  
Energy Saving ◽  
Subjective Time ◽  
Durable Good ◽  
Discount Function ◽  
Hyperbolic Discount ◽  
The One ◽  
Two Parameter ◽  
Difference Effect ◽  
Better Than

Summary: Different shapes of individual subjective discount functions were compared using real measures of willingness to accept future monetary outcomes in an experiment. The two-parameter hyperbolic discount function described the data better than three alternative one-parameter discount functions. However, the hyperbolic discount functions did not explain the common difference effect better than the classical discount function. Discount functions were also estimated from survey data of Dutch households who reported their willingness to postpone positive and negative amounts. Future positive amounts were discounted more than future negative amounts and smaller amounts were discounted more than larger amounts. Furthermore, younger people discounted more than older people. Finally, discount functions were used in explaining consumers' willingness to pay for an energy-saving durable good. In this case, the two-parameter discount model could not be estimated and the one-parameter models did not differ significantly in explaining the data.

To the problem of uncertainty in interpolation of annual runoff

2012 ◽  
Vol 43 (6) ◽  
pp. 833-850 ◽  
Author(s):  
Ziqi Yan ◽  
Lars Gottschalk ◽  
Irina Krasovskaia ◽  
Jun Xia
Keyword(s):  
Cross Validation ◽  
Drainage Basin ◽  
Annual Runoff ◽  
Mean Value ◽  
Regular Grid ◽  
Main River ◽  
Average Annual Runoff ◽  
The One ◽  
Better Than

The long-term mean value of runoff is the basic descriptor of available water resources. This paper focuses on the accuracy that can be achieved when mapping this variable across space and along main rivers for a given stream gauging network. Three stochastic interpolation schemes for estimating average annual runoff across space are evaluated and compared. Two of the schemes firstly interpolate runoff to a regular grid net and then integrate the grid values along rivers. One of these schemes includes a constraint to account for the lateral water balance along the rivers. The third scheme interpolates runoff directly to points along rivers. A drainage basin in China with 20 gauging sites is used as a test area. In general, all three approaches reproduce the sample discharges along rivers with postdiction errors along main river branches around 10%. Using more objective cross-validation results, it was found that the two schemes based on basin integration, and especially the one with a constraint, performed significantly better than the one with direct interpolation to points along rivers. The analysis did not allow identification of possible influence of surface water use.

scholarly journals Improving the energy efficiency of VoIP applications in IEEE 802.11 networks through control of the packetization rate

2017 ◽  
Author(s):  
Rafael Estepa ◽  
Antonio Estepa ◽  
Germán Madinabeitia ◽  
Mark Davis
Keyword(s):  
Energy Efficiency ◽  
Ieee 802.11 ◽  
Rate Control ◽  
Control Algorithm ◽  
Energy Savings ◽  
Dynamic Selection ◽  
802.11 Networks ◽  
Ieee 802.11 Networks ◽  
Rate Control Algorithm ◽  
Selection Of

This paper presents an adaptive algorithm that improves the energy efficiency of VoIP applications over IEEE 802.11 networks. The algorithm seeks to achieve the largest energy savings subject to reaching a minimum speech quality under the prevailing network conditions. The control mechanism used is the dynamic selection of the packet size during the communication.This algorithm has been implemented in an experimental testbed and the results demonstrate that our packetization rate control algorithm can provide energy savings in uncongested IEEE 802.11 networks (up to 30%). Furthermore, under poor network conditions the algorithm can prolong the duration of the call before it is dropped at the expense of a higher energy consumption.

The Optimum Energy Saving Measures for Retrofitting Residential Buildings

2016 ◽  
Vol 41 (1) ◽  
pp. 88-92
Author(s):  
Rong-Yue Zheng ◽  
Jian Yao
Keyword(s):  
Energy Saving ◽  
Energy Savings ◽  
Residential Buildings ◽  
Thermal Conditions ◽  
High Energy ◽  
Cold Winter ◽  
Efficiency Measures ◽  
Optimum Energy ◽  
Potential Energy Saving ◽  
Selection Of

A large number of residential buildings in hot summer and cold winter zone of China are non-energy efficient with poor indoor thermal conditions. Retrofitting residential buildings with energy efficiency measures is thus important for residents. However, this work progressed slowly because practically applicable measures that not only have high energy savings but also improve indoor thermal performance have not been studied. Thus, this paper carried out a simulation study on the selection of suitable energy saving measures for residential buildings in hot summer and cold winter zone of China. Five potential energy saving options are considered and the energy, indoor thermal comfort and economic performance are compared. The results show that adding movable solar shades is the optimum option with all performance indices ranking first. Meanwhile, this measure is also the only acceptable energy saving solution for residents since its payback period is less than the lifespan of a building. As a conclusion, it is recommended to use movable solar shades as a first priority when retrofitting residential buildings.

scholarly journals Evaluating the Energy Efficiency of PCM-Integrated Lightweight Steel-Framed Building in Eight Different Cities of Warm Summer Humid Continental Climate

2020 ◽  
Vol 2020 ◽  
pp. 1-16
Author(s):  
Baurzhan Jangeldinov ◽  
Shazim Ali Memon ◽  
Jong Kim ◽  
Marzhan Kabdrakhmanova
Keyword(s):  
Energy Efficiency ◽  
Phase Change ◽  
Energy Savings ◽  
Constant Volume ◽  
Lightweight Steel ◽  
Heating And Cooling ◽  
Warm Summer ◽  
The Impact ◽  
Continental Climate ◽  
Selection Of

Phase change materials have been applied to a building framework to decrease energy and fossil fuel consumption as well as make the building sector more sustainable. Lightweight structures are attractive and increasingly being used in residential buildings. Hence, in this research, the energy efficiency and thermal performance of buildings located in eight various cities (Helsinki, Kiev, Saint Petersburg, Moscow, Stockholm, Toronto, Montreal, and Kiev) of warm summer humid continental climate (Dfb) were evaluated. The impact of heating and cooling energy savings pattern on the selection of optimum phase change material for each city has been demonstrated. In addition, the impact of volume of PCM, precisely the effect of varying and constant volume, on energy savings was assessed for the lightweight steel-framed building. Simulations were performed in EnergyPlus by applying eleven melting temperature ranges of PCM. Test results demonstrated that energy savings were higher in the swing season and the maximum temperature reduced during these months was 3.3°C. Heating and cooling energy savings were found to strongly influence the selection of optimum PCM. In cities where cooling energy savings were the highest, the optimum PCMs were PCMs 24-26 while in cities where heating energy savings were the highest, the optimum PCM was found to be PCM 21. For constant volume, the performance of optimum PCM raised when the surface area was enlarged, while the thickness of PCM was reduced. Overall, the application of PCM into lightweight steel-framed residential structure located in warm summer humid continental climate region is a feasible option.

scholarly journals ENERGY SAVING AND INTENSIFICATION OF PRODUCTION

2018 ◽  
pp. 184-187
Author(s):  
DEMUR CHOMAKHIDZE
Keyword(s):  
Energy Efficiency ◽  
Economic Development ◽  
Gross Domestic Product ◽  
Energy Conservation ◽  
Energy Saving ◽  
Energy Savings ◽  
Domestic Product ◽  
Macroeconomic Indicators ◽  
Concrete Materials ◽  
Set Up

The report analyzes the role and importance of energy conservation for Georgia. Based on concrete materials, the effectiveness of social labor and energy savings on gross domestic product (GDP) is comparable to each other. It is said that the reduction of GDP energy efficiency by 1% is almost the same, and in more than a few years, the result of GDP increase is more than the same as the productivity of public labor. In this regard, the report describes the level and dynamics of major macroeconomic indicators of the economic development of Georgia for 2013-2016. Set up events to improve the situation.

ANALYSIS OF ENERGY EFFICIENCY IN PUBLIC BUILDINGS AFTER IMPLEMENTATION OF ENERGY SAVING MEASURES

2019 ◽  
pp. 314-320
Author(s):  
Ivan Binev
Keyword(s):  
Mathematical Model ◽  
Energy Efficiency ◽  
Energy Saving ◽  
Energy Savings ◽  
Public Buildings ◽  
The Relationship

The report analyzes energy efficiency in public buildings. A mathematical model was developed describing the relationship between energy savings and heated space in buildings with energy saving measures implemented. The resulting model can be used to predict energy savings of buildings with an accuracy of 82%. The results facilitate the process of determining the energy savings of buildings in which energy-saving measures are to be implemented.

scholarly journals POSSIBILITIES FOR GROUND WATER USE FOR CONDITIONING OF THE FACULTY OF TECHNICS AND TECHNOLOGIES BUILDING IN YAMBOL

2018 ◽  
Vol 16 (2) ◽  
pp. 166-169
Author(s):  
Ivan Binev
Keyword(s):  
Energy Efficiency ◽  
Water Supply ◽  
Ground Water ◽  
Energy Saving ◽  
Heat Pump ◽  
Water Use ◽  
Pump System ◽  
Heat Pump System ◽  
Heat Demand ◽  
Selection Of

The purpose of the report is to analyze the possibilities for using heating energy for the building of the Faculty of Technics and Technology of Yambol at Trakia University of Stara Zagora, Bulgaria, provided by renewable sources. The selection of the water-water heat pump system is made after determining the heat demand for the building when applying the energy saving measures proposed in the energy efficiency audit. The possibilities for using groundwater for water supply were studied to heat the building.

scholarly journals Multi-Criteria Decision-Making Method for Sustainable Energy-Saving Retrofit Façade Solutions

2021 ◽  
Vol 13 (23) ◽  
pp. 13168
Author(s):  
Ziortza Egiluz ◽  
Jesús Cuadrado ◽  
Andoni Kortazar ◽  
Ignacio Marcos
Keyword(s):  
Decision Making ◽  
Sensitivity Analysis ◽  
Energy Efficiency ◽  
Energy Consumption ◽  
Energy Savings ◽  
Multi Criteria Decision Making ◽  
Effective Energy ◽  
Economic Basis ◽  
Selection Of

The increasing energy consumption levels of buildings within Europe call for controlled consumption and improvements to energy savings and efficiency and effective energy efficiency regulations. However, many aging and energy-inefficient buildings require energetic retrofitting that can employ various façades solutions and insulation materials. The selection of the most sustainable options in each situation therefore requires a decision-making methodology that can be used to prioritize available retrofit solutions based on economic, functional, environmental and social criteria. In this paper, both the methodology and the economic basis of the retrofitting process are presented. The methodology was validated in a case study, and a sensitivity analysis also demonstrated its validity, robustness and stability

scholarly journals Implementation of Innovative Energy Saving Projects to Strengthen the Competitiveness of Domestic Enterprises

2021 ◽  
pp. 188-196
Author(s):  
Olha SOBKO ◽  
Ihor KRYSOVATYY ◽  
Svitlana SMEREKA
Keyword(s):  
Energy Efficiency ◽  
Energy Saving ◽  
Alternative Energy ◽  
Energy Savings ◽  
New Technologies ◽  
Energy Audit ◽  
Economic Relations ◽  
Alternative Energy Sources ◽  
Power Stations

The article deals with the features of innovative projects launch of the energy saving on the enterprises of Ukraine, the necessity of research of essence and specific of introduction of such projects is substantiated concerning the energy-savings on enterprises, their place in the system of economic relations is examined. Foreign experience of market of innovative projects introduction of the energy-saving is investigated, that is one of the basic component elements of effective competition which is beneficial in innovative activity of enterprises, which means the launch of innovative developments, new technologies, knowledge, information. The basic most effective districting over of territory of Ukraine is demonstrated, where realization of innovative projects of the energy efficiency introduction and energy-savings of sunny power stations and surface windy power stations is carried out. Considerable technically accessible potential of power mediums production of redintegrated energy and alternative types of fuel sources in Ukraine is revealed. The basic barriers over introduction of innovative projects in the market of energy-savings are shown, in particular: limited access to technologies and innovations, high cost of services in energy efficiency, lack of skilled specialists, sub-zero quality of suggestion of services in energy efficiency in the market etc. Attention is focused on using of project management for realization of innovative projects, as a basic tool of management, in particular to the energy management and energy audit, and their basic tasks on an enterprise are given. The basic strategic constituents regarding the development of fuel and energy complex of Ukraine and its competitiveness are pointed out, as well the use of alternative energy sources on a period to 2035, that is mentioned in operating Power strategy «Safety, energy efficiency, competitiveness». The mechanism of electric power production stimulation of iterated sources in Ukraine is demonstrated which means the «Green» price for the subjects of managing that produce power from the solar and wind energy.

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