Search

Copyright of Science: Future of Lithuania / Mokslas: Lietuvos Ateitis is the property of Vilnius Gediminas Technical University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Energetika is the property of Lithuanian Academy of Sciences Publishers and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Science: Future of Lithuania / Mokslas: Lietuvos Ateitis is the property of Vilnius Gediminas Technical University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Energetika is the property of Lithuanian Academy of Sciences Publishers and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The high share of global energy costs to create an indoor climate has been of increasing interest to the global community for several decades and is increasingly the focus of policy. This paper analyses the energy performance gap between actual energy consumption and energy demand obtained during the dynamic energy simulation and building certification. To identify the energy performance gap, an existing office of energy efficiency class B was selected as a case study. The simulation program IDA Indoor Climate and Energy was used to create a dynamic energy model, based on the designed documentation and the actual indoor climate parameters recorded by the building management system. The results of the case study showed that the accuracy and reliability of the results presented by the dynamic energy model of the building directly depend on the assumptions. The correct values of the internal heat gains, indoor climate parameters, human behavior, air quality levels at different times of the day and season, HVAC system operation parameters and operation modes, specific fan powers of ventilation systems, the seasonal energy efficiency of cooling equipment and characteristics of sun protection measures have to be selected. [ABSTRACT FROM AUTHOR]

Copyright of Science: Future of Lithuania / Mokslas: Lietuvos Ateitis is the property of Vilnius Gediminas Technical University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Science: Future of Lithuania / Mokslas: Lietuvos Ateitis is the property of Vilnius Gediminas Technical University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Energetika is the property of Lithuanian Academy of Sciences Publishers and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Science: Future of Lithuania / Mokslas: Lietuvos Ateitis is the property of Vilnius Gediminas Technical University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Energetika is the property of Lithuanian Academy of Sciences Publishers and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Science: Future of Lithuania / Mokslas: Lietuvos Ateitis is the property of Vilnius Gediminas Technical University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Science: Future of Lithuania / Mokslas: Lietuvos Ateitis is the property of Vilnius Gediminas Technical University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Energetika is the property of Lithuanian Academy of Sciences Publishers and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The paper investigates cases of separate and combined heat and power generation, providing data for comparison of their energy efficiency. It was shown that the official translation of the Directive of the European Parliament and of the Council 2004/8/EC from February 11, 2004 into the Lithuanian language has used the incorrect concept of "thermofication" instead of "cogeneration". The paper shows various possibilities for the use of cogeneration technologies presented in Annex I of the Directive, on the "power capacity vs. electric efficiency" axes. The paper provides data on companies producing microturbines and discusses possibilities to use microturbines in various fields of economic activity. [ABSTRACT FROM AUTHOR]

Copyright of Energetika is the property of Lithuanian Academy of Sciences Publishers and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The renovation of old buildings is essential for the efficient use of energy. Improvement in the thermal characteristics of the building envelope makes a significant effect on energy savings. For assessing the real impact on buildings, energy efficiency of various measures applied in renovation is one of the most important problems. Actual energy savings significantly differ from those calculated according to the methodology described in technical documents. The article analyses 8 renovated buildings. Three main external elements, including walls, windows and roofs, in all buildings were retrofitted. Using theoretical energy savings through each element and knowing the actual savings of the building, actual energy savings through each element are found. Theoretical energy savings for heating after renovation, in every case, are bigger than actual energy consumption for heating before renovation. There is a big difference between theoretical and actual savings after renovation, sometimes up to 2 times. The paper describes dependency between the envelope area of buildings and the mismatch factor of theoretical and actual consumption. The payback period of renovated buildings is calculated using theoretical and actual data. The theoretical payback period of renovation is up to 2 times shorter than the actual one. The calculation method for the estimation of the actual payback period using the mismatch factor has been proposed, and the model of the building has been made to calculate its probable payback period. [ABSTRACT FROM AUTHOR]

A review of the principles of differentiation of network tariffs is rather important, because the process of the implementation of new tariffs has already started. To avoid mistakes and to choose the most optimal structure of tariffs, it is expedient to use the best experience of developed countries. The principles of the daytime differentiation after restructuring the power sector were left mainly unchanged. In addition to separated network activity the differentiation according to the voltage level was introduced. Unfortunately, economy of scale is still ignored. In this paper, the method of transposing the existing differentiation according to voltage level into differentiation according to the amount of energy sent through the network is proposed. The tight relation between these two principles is discussed. Seeking to apply the principle of economy of scale, the new method of grouping users according to the level of electricity consumption as the most appropriate approach is developed. On the basis of the analysis a mathematical model is proposed, and results of its testing are presented. [ABSTRACT FROM AUTHOR]

Copyright of Science: Future of Lithuania / Mokslas: Lietuvos Ateitis is the property of Vilnius Gediminas Technical University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The article analyzes changes in energy demand for a greenhouse. The worked out solution to the construction of the building is a partially glazed greenhouse having a glazed roof and open vertical barriers. Design Builder software has been applied for analytical calculations and greenhouse modelling as well as for introducing changes in annual energy demand and establishing temperature variations and regime. The paper reviews the obtained results and diagrams, performs analysis and draws conclusions.Article in Lithuanian

Evaluation of robotic energetics while moving on rough terrain becomes a difficult task without having the information about the movement on even terrain. The problem appears in selection of gaits depending on how much power robot consumes. In this paper, energy consumption of a hexapod walking robot dependence on different gaits and speed is observed. Three most common gaits were used in this experiment: tripod gait, bipod gait and wave gait. Results clearly show that while moving at slow speed, the least energy is consumed by wave gait. As the speed increases, bipod gait selection is required to lower energy consumption. Finally, tripod gait must be selected at even higher speed. Santrauka Nežinant šešiakojo vaikščiojančio roboto energijos sąnaudų judant lygiu paviršiumi, yra sudėtinga įvertinti sąnaudas judant nelygiu paviršiumi bei parinkti taupiausią eiseną ir judėjimo greitį. Darbo tikslas yra išmatuoti suvartojamą energijos kiekį judant skirtingomis eisenomis ir parinkti greičius, kai tikslinga keisti eiseną. Tiriamos trys pagrindinės šešiakojų robotų eisenos: trikojė, dvikojė ir banguojanti. Rezultatai akivaizdžiai rodo, kad, esant mažiems greičiams, mažiausiai energijos robotas suvartoja judėdamas banguojančia eisena. Didėjant greičiui, mažiau energijos suvartojama judant dvikoje eisena, o dar padidėjus – judant trikoje eisena. Reikšminiai žodžiai: šešiakojis robotas, energijos sąnaudos.

The renovation of old buildings is essential for the efficient useof energy. Improvement in the thermal characteristics of thebuilding envelope makes a significant effect on energy savings.For assessing the real impact on buildings, energy efficiencyof various measures applied in renovation is one of the mostimportant problems. Actual energy savings significantly differfrom those calculated according to the methodology described intechnical documents. The article analyses 8 renovated buildings.Three main external elements, including walls, windows androofs, in all buildings were retrofitted. Using theoretical energysavings through each element and knowing the actual savingsof the building, actual energy savings through each element arefound. Theoretical energy savings for heating after renovation,in every case, are bigger than actual energy consumption forheating before renovation. There is a big difference betweentheoretical and actual savings after renovation, sometimes up to2 times. The paper describes dependency between the envelopearea of buildings and the mismatch factor of theoretical andactual consumption. The payback period of renovated buildingsis calculated using theoretical and actual data. The theoreticalpayback period of renovation is up to 2 times shorter than theactual one. The calculation method for the estimation of the actualpayback period using the mismatch factor has been proposed,and the model of the building has been made to calculate itsprobable payback period. Santrauka Senų pastatų atnaujinimas būtinas norint efektyviai vartoti šilumos energiją. Šiam tikslui pasiekti reikia pagerinti tokių pastatų išorinių atitvarų termoizoliacines charakteristikas. Atnaujinant senus pastatus, vienas iš svarbiausių uždavinių – nustatyti, kokį efektą pastatų energiniam efektyvumui suteiks taikomos atnaujinimo priemonės. Metodikos, skirtos išorinių pastato atitvarų atnaujinimo poveikio energiniam efektyvumui nustatyti, pateikiamos galiojančiuose statybos techniniuose reglamentuose. Tačiau susiduriama su problema lyginant teorinius pastatų energijos sutaupymo atvejus su faktiniais, nes gaunami dideli skirtumai tarp jų. Straipsnyje pateikiama aštuonių atnaujintų namų Vilniuje ir Šiauliuose faktinio energijos suvartojimo patalpoms šildyti prieš ir po atnaujinimo analizė, gauti rezultatai palyginami su teoriniais skaičiavimais. Palyginamas tiriamų pastatų atnaujinimo atsipirkimo laikotarpis, apskaičiuotas pagal teorinius ir faktinius duomenis. Sukuriamas pastato modelis ir, įvertinant paklaidą tarp teorinių ir faktinių energijos sutaupymo atvejų, apskaičiuojamas jo atnaujinimo atsipirkimo laikotarpis bei pateikiamos išvados. Reikšminiai žodžiai: atnaujinimas, pastatas, energijos suvartojimas, termoizoliacija, atsiperkamumas.

Copyright of Science: Future of Lithuania / Mokslas: Lietuvos Ateitis is the property of Vilnius Gediminas Technical University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Science: Future of Lithuania / Mokslas: Lietuvos Ateitis is the property of Vilnius Gediminas Technical University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This article presents energetic and economics parameters, the costs of harvesting one hectare, the actual fuel consumption, total energy of buckwheat yield and coefficient of the energetic efficiency while windrow harvesting, stripping-threshing and direct combining (conventional technology) the crop of buckwheat. From the energetic point the stripping-threshing technology of buckwheat harvesting has the following coefficient of energy efficiency for one ton of buckwheat grain is 5.04, i.e. 1 MJ energy input generates over 5 MJ of energy. Compared with traditional buckwheat harvesting technology, the output of a combine SR 500 in the stripping-threshing technology increases twice, fuel consumption decreases round 40 %, harvesting costs declines 39.5 EUR per hectare (138 Lt). [ABSTRACT FROM AUTHOR]

Copyright of Politologija is the property of Vilnius University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)