Šiame darbe pateikta gluosninių žilvičių auginimo, ruošimo bei naudojimo analitinė apžvalga, gluosnių auginimo technikos ir technologijų energetinis vertinimas, nesubrendusių gluosnių pjaustinio ilgio teoriniai tyrimai naudojant žolinių augalų smulkintuvą. Taip pat eksperimentiškai nustatytos gluosnių fizikinės – mechaninės savybės, poveikis aplinkai deginant skirtingo pjaustinio gluosnius. Tyrimai atlikti naudojant 10 kW biokuro katilą, skirtą kūrenti energetinių augalų skiedroms, briketams, paletėms. Nustatytos kenksmingų medžiagų (CO2 , CO, NO, NOx) emisijos į aplinką deginant skirtingo tipo smulkintuvais susmulkintus gluosnius. / In this work the willow cultivation, preparation and use of analytical review of willows growing energy technology and technology assessment in juvenile willow cuttings-length adaptation of the theoretical studies of herbaceous plants shredder. It is well established experimentally rushes physical - mechanical properties of the environmental impact of combustion of different willow cuttings. Investigations were carried out using a 10 kW biofuel boiler to burn energy crops for wood chips, briquettes, pallets. Down (CO2 , CO, NO, NOx) emissions into the environment by burning different types of chopped willow cutter.

Baigiamajame magistro darbe nagrinėjamos grunto ir atliekinės pastato šilumos panaudojimo galimybės mažaenergiame pastate, Vilniaus mieste, Lietuvoje. Suskaičiuoti keturi pastato energijos balansų variantai, naudojant ”CASAnova” kompiuterinę skaičiavimo programą, su skirtingais atitvarų šilumos perdavimo koeficientais. Pastate taikomos dvi energijos taupymo priemonės. Pirmoji yra gruntinis šilumokaitis naudojamas šviežio oro pirminiam pašildymui mechaninio vėdinimo sistemoje, kurio skaičiavimai atliekami ”GAEA” programa. Antroji yra nuotekų šilumos atgavimo šilumokaitis, naudojamas į pastatą tiekiamo šalto vandens pirminiam pašildymui, atgaunant dalį šilumos iš duše susidariusių nuotekų. Pastatui reikiamas metinis šilumos ir vėsos energijos kiekis gaminamas šilumos siurbliu su vertikaliu gręžiniu grunte, kurio skaičiavimams naudojama ”EED” programa. Gręžinių gyliai yra suskaičiuoti kiekvienam pastato energijos balansų variantui. Atlikti ekonominiai skaičiavimai rodo gruntinio ir nuotekų šilumos atgavimo šilumokaičių įdiegimo pastate ekonominę naudą. Pateikti rezultatai rodo kiekvieno varianto energijos poreikius ir gręžinio grunte gylį priklausomai nuo pastato varianto atitvarų šiluminių savybių bei taikomų energijos taupymo sprendimų. Darbą sudaro 9 dalys: įvadas, 6 skyriai, išvados ir pasiūlymai, literatūros sąrašas. Darbo apimtis – 64 psl. teksto, 41 paveikslai, 14 lentelės, 31 bibliografinis šaltinis. / The final master thesis presents technical analysis of low-energy residential building in Vilnius, Lithuania. Building has low temperature floor heating, mechanical ventilation with heat recovery unit and hot water preparation with buffer tank systems. Using “CASAnova” software is calculated fourth energy balances of building according fourth different heat transfer coefficients of the walls. All heating and cooling energy demand of a building is generated from the ground. It is made by using a heat pump with single borehole. A calculation of borehole sizing is made with “EED” software. Two energy saving technologies are analysed for a building. The first idea is to reduce heat energy consumption of hot water preparation. There is calculated benefit of waste water heat recovery heat exchanger which function is to pre-heat hot water using waste water from the shower. Second idea is to reduce heat energy consumption for fresh air heating in air handling unit. There is calculated benefit of earth-to-air heat exchanger using “GAEA” software. Final result of all calculations shows influence of heat transfer coefficient and energy saving technologies to building annual energy balance and depth of borehole. Economic benefit of using energy saving technologies is calculated. Structure: introduction, 6 chapters, conclusions and suggestions, references. Thesis consists of 64 p. of text, 41 figures, 14 tables and 31 bibliographical entries.

The aim of the work is to investigate heat transfer of the staggered tube bank to downward statically stable foam flow.

The starting time of the three – phase asynchronous motors can be determined using the equation of the movement of the electric drive putting down into this equation the mechanical characteristics of the mechanism and motor. The mechanical characteristics of the motor often are expressed by the Kloss formula, but this formula can't be used for the up to date asynchronous motors, wich have very different mechanical characteristics. The analysis of the method letting to express the mechanical characteristics of the motor as the sum of two components: one according Kloss formula, another – as a power function, are carried out. Using this expession of the mechanical characteristics of the induction motor and the equation of the movement of the drive, the method for determination of the starting time is developed.

Energijos sąnaudų mažinimas tampa vis aktualesne problema, kuri turi būti sprendžiama visose energetikos srityse. Efektyviai naudojamas įrenginys turi ne tik kokybiškai atlikti savo funkcijas, bet tai padaryti su kuo mažesnėmis išlaidomis. Šiuo metu Lietuvoje naudojama daugiau nei 5 tūkstančiai keleivinių liftų, dauguma iš jų pradėti eksploatuoti daugiau kaip prieš 25 metus ir jau gerokai viršija gamintojo rekomenduojamą amžių. Šio darbo tikslas – išanalizuoti Šiaulių miesto keleivinių liftų sistemos darbą, įvertinti nuostolius dėl nepakankamo įrenginių išnaudojimo, bei nustatyti jų atsiradimo priežastis ir šiuolaikinio patikimumo įrenginių pritaikymo galimybes. Statistinių duomenų apie liftų gedimus analizė buvo atliekama panaudojant programinį paketą STATISTICA. Keleivinių liftų gedimų atstatymo trukmės pasiskirstę pagal logaritminį – normalinį, o trukmės tarp gedimų – eksponentinį skirstinius. Tokie skirstiniai būdingi normalios eksploatacijos laikotarpiu, tačiau maža negedimo tikimybė (0,28), trumpas laikas tarp gedimų (1030 val.) ir didelis gedimų dažnis rodo, kad artėja trečiasis darbo periodas – senėjimo ir dilimo prosesas. Įvertinus dispečerizacijos įtaką paaiškėjo, kad šis būdas pagerina pataisomumo rodiklius, tačiau reikalinga išsamesnė pagrindinių mazgų nuotolinė kontrolė. Buvo įvertintos liftų aptarnavimo išlaidos. Didžiąją dalį išlaidų 86,7 % dispečerizuotiems ir 87,6 % nedispečerizuotiems liftams sudaro remonto išlaidos. Vartotojai (keleiviai) dėl liftų prastovų... [toliau žr. visą tekstą] / Decreasing energy input however becomes a problem, which can be solved in all energetic countries. Mechanisms effectively are not using qualitatively and correspond at the functions, but they have to do it in less expense. Today in Lithuania is using more than 5 thousand passengers’ lifts, they were begin to use before 25 years and now they are exceed producer in recommended time. This work purpose is to analyze Šiauliai city elevators’ system work, to evaluate damage for mechanisms’ using and to find out originate reasons and security mechanisms using choice for the following days. The statistics information about elevators’ breakdown analysis was done by the program packet STATISTICS. The elevators’ breakdown origin duration was repartitioned by log - normal and the term between breakdowns by exponential. They are normal in exploitation time, but chance of none breakdowns (0,28), the short time thought breakdowns (1030 hours) and a lot number of breakdowns show that the third period comes with obsolescence and wane processes. The dispatching influence was evaluated and developed that this manner makes better indexes but the basics node control is needed. Elevators’ using expenses were valuated. The huge part of expenses 86,7% dispatching and 87,6% not dispatching lifts compose repair expenses. Users have damage by outage of lifts, which make 0,2 % and 0,7% expenses. The repair reasons are not trust the mechanisms. The security of using to days technologies need to increase:... [to full text]

Didžiulės elektros energijos vartojimo sąnaudos karkasinių namų gamyboje ganėtinai ženkliai didina gamybos savikainos kaštus, kas tiesiogiai atsiliepia įmonės pelnui. Medienos apdorojimo pramonės produkcijos galima pagaminti gerokai daugiau (arba pagaminant tą patį kiekį suvartoti mažiau elektros energijos), ne vien tik kuriant naujus didesnio našumo medienos apdirbimo įrenginius, bet ir racionaliai naudojant esamus, bei nuolat juos modernizuojant. Šiame darbe tiriamas karkasinius namus gaminančios ir statančios įmonės UAB „Namų statyba“ elektros energijos suvartojimas. Buvo siekiama nustatyti elektros energijos taupymo galimybes, iš įmonės elektros energijos suvartojimo pereiti prie energijos sunaudojimo normos vienam karkasiniam namui pagaminti. Atlikus tyrimą nustatyta, kurioje medienos apdirbimo operacijoje galima būtų sumažinti elektros energijos suvartojimą. Taip pat pateikiami pagrįsti elektros energijos efektyvumo didinimo būdai. / Engineering prime costs increase because of a great consumption input of electricity energy at framework house manufacture, which directly influence company profit. It is possible to produce much more wood processing industry output (or to consume less electricity energy while producing the same quantity), not only by creating new mechanisms of greater wood processing productivity, but also by racionally using the present ones and constantly modernizing them. The consume of electricity energy of the JSC „Namų statyba“ which specializes at manufacturing and building framework houses is being researched at this work. The target was to estimate the saving potencial of electricity energy and to come from company electricity energy consume to the norm of electricity energy that is necessary to build a single framework house. Wood processing operation at which it is possible to reduce electricity energy consumtion was estimated after the research. The reasoned methods how to increase the effectiveness of electricity energy are presented as well.

Informational equipment are difficult systems which performance reliability depends on a number of internal and external factors. One of the most important external factors is the quality of supplied electricity. Dependence of performance reliability of informational equipment upon the quality of supplied electricity, the impact of equipment themselves on the feeding system/net are discussed in this work. The standards of quality of electricity are overviewed, the deviations of voltage and their influence over informational equipment are evaluated. Means of increase of reliability, their structure and course of performance are described, their advantages and weaknesses are specified. Electrical ground system has major influence over reliable performance. In case of incorrect installation of the system it is possible to cause system foul-ups or even put a human life at risk. The influence of informational equipment over feeding net/system is evaluated in this work, the example of calculation of workload is presented.

The theme of Master project of Energetics engineering is actual because in nowadays it is important not only design and functionality of bicycle, but also safety and technological tests of bycicle frame, fork and other part corresponding to international standarts. In Master project was created system for dynamic changing force applying on dynamic pedal and wheel strenght tests. Results of practical pedal pushing research and computations of modelated pedaling system were similar. Analysis of pneumatic cylinder and proportional pressure regulator (using Centaurus Plus modeling program) showed that it is necessary to reduce cylinder working cell volume to enable system to repeat 3 Hz set signals. Using algorithms models was created program for data input, processing and visualizing of testing stand. This program was kindly evaluated by specialists of Technological Test center of Faculty of Technology.

The work is directed for one of alternative energy resources – renewable sources of energy. The main task is to examine potential produce biogas out of maize silage. The object of analyses was a biogas plant operated on different organic wastes in the pigs farm of UAB “Lekeciai”. The technologies of biogas production and energy input were analysed in this work. Acording to empirical equations there were developed an estimation methodology of energy consumption in biogas plant. A Energy consumption of technological equipment and energy consumption of maize silage has been investigated and determined. Energetic potential of maize silage have been investigated during experiments. Energetic efficiency of biogas plant given different composition of organic wastes has been determined. Have been estimated efficient of producing biogas out of silage maize.

Pateikto magistrantūros baigiamojo darbo tikslas – išmatuoti degimo proceso kokybę, atlikti reguliavimus. Išnagrinėti galimybę automatiškai ir optimaliai valdyti kieto kuro katilo degimo procesą. Palyginti gautus eksperimento rezultatus, vykdant degimo proceso reguliavimus. Darbe išanalizuotas medienos biomasės panaudojimo Lietuvoje potencialas. Pateiktos technologijos šiluminės energijos gamybai decentralizuotam šildyme. Pristatyti automatinio reguliavimo sistemos principai. Pateikta tyrimo metodika, rezultatai. / The aim of master thesis is – measure results burning process quality and curry out regulation. The research possibility control solid fuel boilers burning process. There is made an analysis of biomass utilizing potential in Lithuania. There is listed technology’s in heating production. Also in this work are given the rules of system automatic control. There is a listed research methodic, results.