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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Vytápění a větrání v rodinném domě typu bungalov / Space heating and ventilation in a bungalow family house

Menšík, Marek January 2018 (has links)
This diploma thesis deals with design of ventilation and heating of bungalow single-storey house. The work is divided into three parts. In the first part is presented the design of the house with calculation of heat losses. The second part deals with the design, calculations and regulation of the heating of the house. In the third part there is designed a system of forced ventilation for the house.
22

X Návrh a optimalizace tepelného čerpadla pro mateřskou školu / Heat pump design and optimization for nursery building

Mračková, Alžběta January 2008 (has links)
The point of this diploma thesis is heating design with use of heat pump (HP) for nursery building. The first part introduces problems of HP, familiarization with historical development, working principle, description of components, working cycles, partition of heat pumps due to the source of lowpotential heat and possibilities of working operations. In practical part then follows heat loss computation of own building, suitable heat pump choice, economic balance, investment recovery and evaluation of this solution.
23

Porovnání výpočtu tepelných ztrát dle ČSN 06 0210 a ČSN EN 12831 / Comparison of heat losses calculation by CSN 06 0210 and CSN EN 12831

Elcner, Jakub January 2008 (has links)
The diploma thesis deals with comparison of heat loss calculation by CSN 06 0210 and CSN EN 12831. This work contains short introduction to the heat loss calculation, definition of basic terms, detailed analysis of heat loss calculation by both standards, description of exemplar buildings, heat loss calculation and heat requirement for heating of buildings according to particular standards. At the end of the work the comparison and discussion of calculation results is presented.
24

Návrh vytápění rodinného domu s vnitřním bazénem. / Design of heating system for family house.

Fišer, Petr January 2008 (has links)
The assignment of my diploma thesis is to design the family house heating system. The source of energy is heat pump for heating which takes heat from areal collector.
25

Rekonstrukce otopné soustavy rodinného domu po celkovém zateplení / Design of heating system reconstruction for family house after complete overcladding

Doležal, Libor January 2011 (has links)
The thesis deals with the reconstruction of the heating system for a family house after complete overcladding. The first part is dedicated to an introduction of the subject under consideration. The next step is the calculation of heat loss.. A suitable method of insulation including economical recovery was designed according to the research of potential insulation materials, then heat loss were re-calculated. Another point is to determine a suitable temperature gradient and select the most appropriate source of heat and hot water preparation. The pressure loss circuit through the various radiators were calculated and balanced by thermostatic radiator valves. Finally, the insurance elements of the heating system were checked and the drawings documentation were prepared.
26

The Influence of Ethnicity on Local and Whole-Body Heat Loss Responses During Exercise in the Heat: A Comparison Between Young Canadian Men of Black-African and Caucasian Descent

Muia, Caroline 28 November 2019 (has links)
This thesis sought to evaluate whether the increased risk of heat-related illness observed in black-African descendants stems from impairements in local- and whole-body heat loss responses in this ethnic group. To evaluate this, in separate studies local- (study 1) and whole–body (study 2) heat loss responses were compared in young men (18-30 y) of black-African (n=21) and Caucasian (n=21) descent, matched for physical characteristics and fitness and born and raised in the same temperate environment. In study 1, we compared nitric oxide-dependent skin blood flow and sweating responses in young men of black-African (n=10) and Caucasian (n=10) descent during rest, exercise, and recovery in the heat. Both groups rested for 10-min, and then performed 50-min of moderate-intensity exercise at 200 W/m2, followed by 30-min of recovery in hot-dry heat (35°C, 20% RH). Local cutaneous vascular conductance (CVC%max) and sweat rate (SR) were measured at two forearm skin sites treated with a) lactated-Ringer (Control), or b) 10 mM NG-nitro-L-arginine methyl ester (L‐NAME, NO synthase-inhibitor). L-NAME significantly reduced CVC%max throughout rest, exercise, and recovery in both groups (both p<0.001). However, there were no significant main effects for the NO contribution to CVC%max between groups (all p>0.500). L-NAME significantly reduced local SR in both groups (both p<0.050). The NO contribution to SR was similar between groups such that L-NAME reduced SR relative to control at 40 and 50 min into exercise (both p<0.050). In study 2, we assessed whole-body total heat loss (evaporative + dry heat exchange) in black-African (n=11) and Caucasian (n=11) men using direct calorimetry. Participants performed three, 30-min bouts of semi-recumbent cycling at fixed metabolic heat productions (and therefore matched heat loss requirements between groups) of 200 (light), 250 (moderate), and 300 W/m2 (vigorous), each followed by 15-min recovery, in dry heat (40°C, ~13% relative humidity). Across all exercise bouts, dry (p=0.435) and evaporative (p=0.600) heat exchange did not differ significantly between groups. As such, total heat loss during light, moderate and vigorous exercise was similar between groups (p=0.777), averaging ((mean (SD)); 177 (10), 217 (13) and 244 (20) W/m2 in men of black-African descent, and 172 (13), 212 (17) and 244 (17) W/m2 in Caucasian men. Accordingly, body heat storage across all exercise bouts (summation of metabolic heat production and total heat loss) was also similar between the black-African (568 (142) kJ) and Caucasian groups (623 (124) kJ; p=0.356). This thesis demonstrates that ethnicity does not influence NO-dependent cutaneous vasodilation and sweating in healthy, young black-African descent and Caucasian men during exercise in the heat. Furthermore, we extend upon these observations by showing no differences in whole-body dry and evaporative heat exchange and therefore body heat storage.
27

Energieffektivisering genom ombyggnad : Med hjälp av VIP-Energy / Energy efficiency through renovations : With VIP-Energy

Aliu, Jeton, Youkhanis, Ledia January 2013 (has links)
Detta examensarbete har genomförts i samarbete med Värmex AB där vi har haft Anders Ericsson som handledare, och Peter Hansson (Sweco) som handledare från skolan, Kungliga tekniska högskolan i Haninge. Idag är energianvändningen i flerbostadshus en stor fråga att ta itu med, och för varje byggnadsprojekt skall en energideklaration som visar mängd köpt energi göras. Vi strävar idag efter att minska energianvändningen i flerbostadshus med 50 % till 2050. I denna analys beskriver vi vilka åtgärder man kan ta an för att minska just energianvändningen i ett specifikt flerbostadshus belägen i kommunen Nacka i Stockholm. Då denna byggnad stått från år 1949 utan större underhållning har det visat sig att byggnaden står över BBRs krav gällande energianvändning (90 kWh/m2), och stor anledning är klimatskalet. Källor visar även att delar av klimatskalet så som fasad etc. bör ändras inom 30 år efter det att det byggts, vilket inte har gjorts. Vi har genom en programvara, VIP-Energy valt att utföra denna analys. Med hjälp av offentliga handlingar från stadsbyggnadskontoret så som plan – sektion – fasadritningar har vi mätt nödvändiga mått som vi knappat in i programmet. Även information som byggnadsmaterial, läge på byggnaden och uppvärmningssystem har varit nödvändiga. Jämförelse mot BBRs krav har gjorts automatiskt i programmet och det är sådan slags information vi utgått ifrån.  Då vi i denna analys valt att fokusera på klimatskal där tak, golv, väggar, fönster och dörrar ingår visar resultatet att lägre u-värden på byggnadsdelar bidrar till lägre energianvändning. Studier visar att ca 35 % av värmeförlusterna är via fönster, och detta överensstämmer med byggnaden som denna analys är baserad på. Som lösning till detta har vi valt att byta fönster till 2-glas fönster med isolleruta vilket har betydligt lägre u-värde än de vi har idag. Vi vill även förbättra karmen och fogen kring fönstren för att minska transmissionsförlusterna och eventuella drag i bostäderna, vilket i sin tur leder till bättre komfort och skönare atmosfär. Detsamma gäller yterdörrarna som behöver bytas för att hålla värmen inne. Utvändig isolering i ytterväggen bidrar även med förbättringar kring u-värde och energianvändning. Originalhuset visade att byggnadens genomsnittliga U-värde ligger på 0,656W/m2K och energianvändningen ligger på 96 kWh/m2 per år. Enligt BBRs krav för äldre byggnader ska u-värdet ligga på 0,400W/m2K och energianvändningen på 90kWh/m2 per år. Energibalansberäkningen visar nya värden på byggnaden, vilket är totala u-värde på 0,409 W/m2K samt energianvändningen på 64 kWh/m2. / This degree project has been written in collaboration with Värmex AB, with the generous help of Anders Ericsson as our fellow adviser and Peter Hansson (Sweco) our mentor from the Royal institute of technology located in Haninge.   Today we find questions pertaining to energy consumption in apartment blocks of real significance; with each building project a declaration that shows the amount of energy consumed is of outmost importance. We strive to reduce energy consumption in apartment blocks by 50 % until year 2050. In this degree thesis, we aim to describe measures and solutions to lower the consumption of energy in a specific apartment block located in Nacka, Stockholm.   This building has been standing quite untouched and unmarked since 1949, yet it is still in compliance with the demands stated by BBR concerning energy efficiency, in large because of its climate shell. Sources show that greater parts of its outer shell for example the front, should have been repaired during the first 30 years, and the matter is still to be solved. The use of a computer software VIP-Energy has enabled us to state a hypothesis. With the help of public documents from Housing And Urban Development Town Building Office (HUD) giving us an overview of the different dimensions of the building, we've been able to plot all this data into the software. Information such as building materials, location, heating systems have also been necessary in our analysis. Results are automatically compared to the demands required by BBR. It is through experimentation of this data that we have been successful in collecting our results.  In the analysis, we chose to focus on the climate shell that constitutes: roof, floors, walls, windows and doors. Our results show that lower U-values conduce better energy efficiency. Studies show that almost 35 % of energy loss in a building is caused by the windows of the building, this this is consistent with the building which this analysis is based on. We have solved this by changing sheet glass that is energy efficient. We also aim to change the frame and seams surrounding the windows, in order to lower transmission losses and possible draughts in the apartments. This will result in hopefully a higher degree of comfort and refreshing atmosphere. The same changes apply to entry doors in order to keep energy loss to a minimum. Also an external insulation in the outer wall contributes to improvements on u-value and use.  The original building shows an average U-value of 0,656W/m2K and the energy consumption is 96 kWh/m2 per year. According to BBR, older buildings should have a U-value of 0,400W/m2K and an energy consumption of 90kWh/m2 per year. Energy balance calculation show new values for the building were the u -value should be set to 0,409W/m2K, and energy consumption should be set to 64kWh/m2.
28

Significant energy saving in industrial natural draught furnace: A model-based investigation

Karem, S., Al-Obaidi, Mudhar A.A.R., Alsadaie, S., John, Yakubu M., Mujtaba, Iqbal M. 28 March 2022 (has links)
yes / In all industrial petrochemical plants and refineries, the furnace is the source of heat resulting from fuel combustion with air. The model-based furnace simulation is considered one of the efficient methods help to reduce the energy loss and maintain fixed refinery revenues, conserving energy, and finally reducing external fuel consumption and total fuel cost. In this paper, a model-based simulation is carried out for a natural air draught industrial scale furnace related to Liquified Petroleum Gas (LPG) production plant in Libya to thoroughly investigate the most responsible factors in lowering the furnace butane exit temperature, which is supposed to be two degrees Fahrenheit higher than inlet temperature. Therefore, to resolve this industrial problem, Aspen Hysys V10, coupling with EDR (exchanger design and rating) is used to carry out rigorous model-based simulation. This is specifically used to assess the impact of heat loss from inside the firebox to the surrounding medium and heat loss from the furnace stack and walls, besides the effect of excess air on the furnace efficiency. Furthermore, this research intends to verify whether the operating conditions, such as furnace tubes inlet flow rate, temperature and pumping pressure, are conforming to the upstream process design specifications or need to be adjusted. The results confirm that increasing furnace outlet temperature two degrees Fahrenheit from off specification 190 °F instead of 184 °F is successfully achieved by decreasing upstream stream flowrate 25% below the operating value and cutback excess air gradually until 20%. Also, the results clarify the necessity of increasing the flue gas temperature by 7% over design condition, to gain a significant reduction of heat loss of 31.6% and reach as low as 35.5 MBtu/hr. This improvement is achieved using optimum operating conditions of an excess air of 20%, and flue gas oxygen content of 3.3% delivered to stack. Accordingly, the furnace efficiency has been increased by 18% to hit 58.9%. Furthermore, the heat loss from the furnace walls can be also reduced by 68% from 5.41 MBtu/hr to 1.7 MBtu/hr by increasing the refractory wall thickness to 6 in., which entails an increase in the furnace efficiency by 3.66% to reach 58.96%. Decreasing the heat loss fraction through the refractory wall, pip doors, expansion windows and refractory hair cracks would also increase the efficiency by 21% to reach a high of 59.7%. Accordingly, a significant reduction in daily fuel consumption is observed, which costs 1.7 M$ per year. The outcomes of this research clearly show the potential of reducing the operation and maintenance costs significantly.
29

Numerical Investigation on CO Emissions in Lean Premixed Combustion / 希薄予混合燃焼におけるCO排出に関する数値解析による研究

Yunoki, Keita 23 March 2022 (has links)
京都大学 / 新制・課程博士 / 博士(工学) / 甲第23882号 / 工博第4969号 / 新制||工||1776(附属図書館) / 京都大学大学院工学研究科機械理工学専攻 / (主査)教授 黒瀬 良一, 教授 中部 主敬, 教授 岩井 裕 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM
30

3D computational fluid dynamics study of a drying process in a can making industry

Tanthadiloke, S., Chankerd, W., Suwatthikul, A., Lipikanjanakul, P., Mujtaba, Iqbal M., Kittisupakorn, P. 05 August 2016 (has links)
Yes / In the drying process of a can making industry, the drying efficiency of a thermal drying oven can be improved by adjusting the volumetric air flow rate of the blower. To maximize drying efficiency, an optimal flow rate is needed. Consequently, a three-dimensional computational fluid dynamics (CFD) is used to provide simulation according to the response of air velocity, air temperature and evaporated solvent concentration with respect to changes in volumetric air flow rate in the drying oven. An experimental study has been carried out to determine the evaporation rate of the solvent. To validate the models, the process data obtained from the CFD is compared with that obtained from actual data. In the accurate models, the simulation results demonstrate that the decrease in volumetric air flow rate provides no major discrepancy of the air velocity patterns in all dimensions and decreases the maximum temperature in the oven. Consequently, this decrease in volumetric air flow rate rapidly increases the evaporated solvent concentration in the beginning and then gradually decreases over the length of the oven. In addition, further reduction of the flow rate gives lower heat loss of the oven up to 83.67%. / The authors would like to thank The Thailand Research Fund (TRF) under The Royal Golden Jubilee Ph.D. Program (PHD/0158/2550), The Institutional Research Grant (The Thailand Research Fund) (IRG 5780014) and Chulalongkorn University (Contract No. RES_57_411_21_076) for financial support to this work.

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