The influence of air-conditioning operation schedule on energy consumption for cooling

U radu je data analiza uticaja ražima rada klimatizacionog postrojenja na potrošnju energije za hlađenje. Sprovedena analiza je izvršena uz pomoć kompjuterskog programa za dinamičku simulaciju termičkog ponašanja klimatizovane prostorije. Program je razvijen na Katedri za termotehniku Mašinskog fakulteta u Beogradu. Ispitivana su tri različita režima rada sistema za klimatizaciju, dnevni tok toplotnog opterećenja i dnevna potrošnja energije za hlađenje, pri letnjim projektnim uslovima za Beograd. Dobijeni razultati simulacije su upoređeni i dati su podaci o dnevnoj uštedi energije za hlađenje.In this paper, presented is the influence of air-conditioning operating schedule on the daily cooling energy consumption. Analysis has been made on the basis of a computer program for dynamic simulation of an air-conditioned room thermal behavior. The program has been developed at the Department for Thermal Engineering at the Faculty of Mechanical Engineering, University of Belgrade. Analysed are three different air-conditioning operating schedule cooling loads and daily energy consumption, at summer design conditions for Belgrade. The obtained results have been compared, and here upon given a review of the daily energy savings

The influence of air-conditioning operation schedule on energy consumption for cooling

U radu je data analiza uticaja ražima rada klimatizacionog postrojenja na potrošnju energije za hlađenje. Sprovedena analiza je izvršena uz pomoć kompjuterskog programa za dinamičku simulaciju termičkog ponašanja klimatizovane prostorije. Program je razvijen na Katedri za termotehniku Mašinskog fakulteta u Beogradu. Ispitivana su tri različita režima rada sistema za klimatizaciju, dnevni tok toplotnog opterećenja i dnevna potrošnja energije za hlađenje, pri letnjim projektnim uslovima za Beograd. Dobijeni razultati simulacije su upoređeni i dati su podaci o dnevnoj uštedi energije za hlađenje.In this paper, presented is the influence of air-conditioning operating schedule on the daily cooling energy consumption. Analysis has been made on the basis of a computer program for dynamic simulation of an air-conditioned room thermal behavior. The program has been developed at the Department for Thermal Engineering at the Faculty of Mechanical Engineering, University of Belgrade. Analysed are three different air-conditioning operating schedule cooling loads and daily energy consumption, at summer design conditions for Belgrade. The obtained results have been compared, and here upon given a review of the daily energy savings

The influence of air-conditioning operating schedule and ventilation needs on energy consumption

U radu je prikazan uticaj režima rada klimatizacionog postrojenja i potreba za ventilacijom na dnevnu potrošnju energije klimatizovane prostorije. Analiza je sprovedena na osnovu kompjuterskog programa za dinamičku simulaciju termičkog ponašanja klimatizovane prostorije. Program je razvijen na Katedri za termotehniku Mašinskog fakulteta, Univerziteta u Beogradu. Analizirana su tri različita režima rada i tri različite količine svežeg vazduha u sistemu za klimatizaciju. Prikazani su tokovi toplotnih opterećenja, energije potrebne za pripremu svežeg vazduha i energije za pogon ventilatora, kao i ukupna potrošnja energije sistema za letnje projektne uslove za Beograd. Dobijeni rezultati simulacije su upoređeni i dati su predlozi za dnevnu uštedu energije koju troši sistem za klimatizaciju.This paper analyses the influence of air-conditioning operating schedule and ventilation needs on the daily energy consumption. Analysis has been made on the basis of a computer program for dynamic simulation of air-conditioned rooms thermal behavior. The program has been developed at the Department for Thermal Engineering at the Faculty of Mechanical Engineering, University of Belgrade. Analyzed are three different air-conditioning operating schedules and three different flow rates of fresh air in the system. Given are cooling loads, energy needed for outdoor air treatment, fan energy consumption and overall daily energy consumption for summer design conditions for Belgrade. The obtained results have been compared, and hereupon given a review of the daily energy savings

The influence of air-conditioning operating schedule and ventilation needs on energy consumption

U radu je prikazan uticaj režima rada klimatizacionog postrojenja i potreba za ventilacijom na dnevnu potrošnju energije klimatizovane prostorije. Analiza je sprovedena na osnovu kompjuterskog programa za dinamičku simulaciju termičkog ponašanja klimatizovane prostorije. Program je razvijen na Katedri za termotehniku Mašinskog fakulteta, Univerziteta u Beogradu. Analizirana su tri različita režima rada i tri različite količine svežeg vazduha u sistemu za klimatizaciju. Prikazani su tokovi toplotnih opterećenja, energije potrebne za pripremu svežeg vazduha i energije za pogon ventilatora, kao i ukupna potrošnja energije sistema za letnje projektne uslove za Beograd. Dobijeni rezultati simulacije su upoređeni i dati su predlozi za dnevnu uštedu energije koju troši sistem za klimatizaciju.This paper analyses the influence of air-conditioning operating schedule and ventilation needs on the daily energy consumption. Analysis has been made on the basis of a computer program for dynamic simulation of air-conditioned rooms thermal behavior. The program has been developed at the Department for Thermal Engineering at the Faculty of Mechanical Engineering, University of Belgrade. Analyzed are three different air-conditioning operating schedules and three different flow rates of fresh air in the system. Given are cooling loads, energy needed for outdoor air treatment, fan energy consumption and overall daily energy consumption for summer design conditions for Belgrade. The obtained results have been compared, and hereupon given a review of the daily energy savings

Multistage ensemble of feedforward neural networks for prediction of heating energy consumption

Feedforward neural network models are created for prediction of heating energy consumption of a university campus. Actual measured data are used for training and testing the models. Multistage neural network ensemble is proposed for the possible improvement of prediction accuracy. Previously trained feed-forward neural networks are first separated into clusters, using k-means algorithm, and then the best network of each cluster is chosen as a member of the ensemble. Three different averaging methods (simple, weighted, and median) for obtaining ensemble output are applied. Besides this conventional approach, single radial basis neural network in the second level is used to aggregate the selected ensemble members. It is shown that heating energy consumption can be predicted with better accuracy by using ensemble of neural networks than using the best trained single neural network, while the best results are achieved with multistage ensemble

Energy savings for residential heating in two pairs of buildings achieved by implementation of actually consumed energy measuring

The paper presents results of heating energy consumption measurements in two pairs of buildings in community New Belgrade for two heating seasons. Influence of these measurements on energy savings is also presented. The measurements were carried out during heating seasons 2002/03 and 2003/04 in buildings in Block 34 and 63, connected to the district heating system "Beogradske elektrane". The buildings in each pair have similar architectural and thermal characteristics. One of the buildings in a pair was "test" building and the other "control" one. In the "test" building the energy consumption for heating of each apartment was measured, as well as total energy consumption for the whole building in the substation. Occupants were able to regulate the heating system. In the "control" building the energy consumption was measured only for the whole building, and occupants had almost no impact on heating energy consumption. The comparison of energy consumption for heating in the "test" and "control" buildings is given in the paper, as well as analysis of the influence of energy consumption measurements on the achieved energy savings

Energy savings for residential heating in two pairs of buildings achieved by implementation of actually consumed energy measuring

The paper presents results of heating energy consumption measurements in two pairs of buildings in community New Belgrade for two heating seasons. Influence of these measurements on energy savings is also presented. The measurements were carried out during heating seasons 2002/03 and 2003/04 in buildings in Block 34 and 63, connected to the district heating system "Beogradske elektrane". The buildings in each pair have similar architectural and thermal characteristics. One of the buildings in a pair was "test" building and the other "control" one. In the "test" building the energy consumption for heating of each apartment was measured, as well as total energy consumption for the whole building in the substation. Occupants were able to regulate the heating system. In the "control" building the energy consumption was measured only for the whole building, and occupants had almost no impact on heating energy consumption. The comparison of energy consumption for heating in the "test" and "control" buildings is given in the paper, as well as analysis of the influence of energy consumption measurements on the achieved energy savings

Neki tehnološki aspekti poboljšanja kod prasadi u odgoju

Effects of utilization of imported boars in comparison to domestic ones were investigated, two imported boar lines Tibora and Tempa were compared in regard to production of their progeny, piglets in rearing, and in the final, third trial, possibilities for use of Biokvas preparation as substitute of yeast in nutrition of piglets in rearing were studied. Obtained results showed that considerably better production is realized by improvement of gain by 17,79% and feed conversion by 12,21% as well as lower cost of gain by 12,16% in progeny of imported boars. No differences were established in weaned piglets deriving from two imported boar lines Tibora or Tempa. Considering that better gain in average by 3,88% and cheaper by 0,57% was realized, it can be concluded that Biokvas as a protein feed can succesfully be used as substitute for yeast in nutiriton of piglets in rearing. In general, use of imported boars as well as application of Biokvas instead of yeast in nutrition of piglets and with objective of improvement of production of rearing piglets were justified.U tri ogleda ispitivani su efekti korišćenja uvoznih u odnosu na domaće neraste, komparacija dvaju linija Tibora i Tempa, uvoznih nerastova na proizvodnju njihovih potomaka, prasadi u odgoju, a u poslednjem trećem ogledu mogućnosti korišćenja biokvasa kao zamene kvascu u ishrani prasadi u odgoju. Ispitivanja, su izvedena na privatnoj farmi svinja Fencaroš u Platičevu - Šabac. U eksperimente je uključeno ukupno 56 odbijene prasadi rase melezi Veliki Jorkšir x Švedski Landras. Ogledi su formirani neposredno pri zalučenju prasadi i trajali su 39 hranidbenih dana pri čemu su prasad bila iste starosti na zalučenju. Dobijeni rezultati su pokazali da se: - ostvaruje znatno bolja proizvodnja, poboljšanjem prirasta za 17,79% i konverzije hrane za 12,21% kao i jeftinijom cenom prirasta za 12,16% kod potomaka nerastova iz uvoza. - nije bilo razlike kod odbijene prasadi korišćenjem dvaju linija nerasta iz uvoza Tibora ili Tempa. - s obzirom na bolji, u proseku za 3,88%, i za 0,57% jeftiniji prirast, biokvas se pokazao da kao proteinsko hranivo može vrlo uspešno zameniti kvasac u ishrani prasadi u odgoju. U celini se pokazala opravdanost korišćenja nerastova iz uvoza kao i primena biokvasa u cilju unapređenja proizvodnje prasadi u odgoju

Prebiotici u ishrani krmača i prasadi

The effects of prebiotic Bio Mos (0.2%) used in nutrition of gestating and sows in lactation, as well as Bio Mos (0.5%) and fructooligosaccharides (0.4%) used in nutrition of suckling piglets were investigated. Obtained results showed that the introduction of additives in mixtures influenced: greater food intake of sows in lactation by 13.75 %, by 14.7% more born piglets and by 3.6% heavier piglets at birth, greater litter weight by 3.1 % at weaning and better intake of pre-starter by 6.7% per litter during lactation. In general, obtained results showed that the use of investigated prebiotic Bio Mos and fructooligosaccharides are recommended for use in nutrition of sows and suckling piglets.Ispitivani su efekti korišćenja prebiotika Bio Mos (0,2%) u ishrani suprasnih i krmača u laktaciji kao i Bio Mosa (0,5%) i fruktooligosaharida (0,4%) kod prasadi na sisi. Dobijeni rezultati su pokazali da se uvođenje korišćenih aditiva u smešama imalo efekte izražene: - većom konzumacijom hrane krmača u laktaciji, za 13,75%, - većim brojem, za 14,7%, oprašene i za 3,6% teže, prasadi na prašenju, - većom telesnom masom legla za 3,1% na zalučenju, - boljom potrošnjom predstartera za 6,7% po leglu tokom laktacije U celini dobijeni rezultati su pokazali da se preporučuje korišćenje ispitivanih prebiotika Bio Mosa i fruktooligosaharida u ishrani krmača i prasadi na sisi