Дисертації: "Gas heaters"

1

Ziesler, Christopher D. "Gas-fired radiant heaters." Thesis, Aston University, 1991. http://publications.aston.ac.uk/9735/.

Повний текст джерела

Анотація:

This dissertation covers four areas of particular interest for the successful application of radiant heating in industrial environments. In it the author tackles the problem of how to predict the thermal comfort produced both by single heaters and also systems of heaters; proposes a method for modelling the mechanisms by which heaters interact with the buildings in which they are installed, in the static and dynamic cases; explores techniques for measuring the radiation produced by heaters; and presents experiments concerned with finding the temperatures and power balances prevailing during normal operation. It is contended that, whilst the generally accepted guides for sizing and operating space heating plant were a good first approximation, there are intrinsic subtleties arising from the fact that the primary mode of heat transfer in this instance is radiative. These nuances are concerned with how best to maximise the heat transfer from the heat source to the heated object; the placement of heaters within a system; and an assessment of the various techniques and strategies involved in controlling a radiant heating system. The conclusions reached are that: if sized and controlled correctly radiant heating systems offer considerable operational advantages over other types of space heating systems in certain applications, in terms of both economy and controllability. The efficacy of radiant heating systems is affected primarily by the control strategy implemented; secondarily, by the structure of the building into which it is installed; and only marginally by all other factors.

Стилі APA, Harvard, Vancouver, ISO та ін.

2

Lu, Chih-Cheng. "SOI CMOS gas sensors using MOSFETs as micro-heaters." Thesis, University of Cambridge, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.619664.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

3

Vilorio, Carlos R. "Gas Chromatography Micro-Chip with High Temperature Interface and Silk Screen Heaters." BYU ScholarsArchive, 2020. https://scholarsarchive.byu.edu/etd/8690.

Повний текст джерела

Анотація:

There has been substantial market demand for a portable Gas Chromatography (GC) system. Throughout the years, much progress has been made on fabricating a micro system that works as well as a benchtop system. Unfortunately, even though many substrates, channel types, channel widths, temperature control systems, and interface solutions have been attempted, existing versions of the micro-GC still fall short of the ideal. This thesis presents the design, fabrication, and testing of a silicon based micro-GC column that presents a solution for interfacing and heating of the chip. A polyimide resin is used to create a durable high temperature low thermal mass interface with the chip, while a silk screen method is demonstrated for easy printing of heaters. Chromatogram results are shown in both Temperature Program and Thermal Gradient runs.

Стилі APA, Harvard, Vancouver, ISO та ін.

4

CARVALHO, MILSON JOSE DE. "CRITICAL ANALYSIS OF THE STANDARDS FOR EVALUATING WATER HEATERS USING GAS FUEL." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 1988. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=33275@1.

Повний текст джерела

Анотація:

CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO
No presente trabalho calcula-se a eficiência de um aquecedor de água, sem evaporação, queimando gás combustível com composição química desconhecida. Faz-se a comparação dos resultados obtidos com duas normas que apresentam formas diferentes de cálculo, ASME (1) e NBS (2). Com os resultados finais, sugere-se um procedimento a ser seguido no cálculo de eficiência de aquecedores.
In this research, the thermal efficiency of a sensible water heater is measured and calculated, burning fuel gas with unknown chemical composition. The experimental results are then compared with the calculated values, when using ASME(1) and NBS(2) standard procedures. Finally and procedure is suggested to calculate the thermal efficiency of such heaters.

Стилі APA, Harvard, Vancouver, ISO та ін.

5

Goodman, Christopher L. "Modeling, validation and design of integrated carbon dioxide heat pumps and water heaters." Thesis, Atlanta, Ga. : Georgia Institute of Technology, 2007. http://hdl.handle.net/1853/22560.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

6

Macek, Jiří. "Návrh vytápění dětského domova." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2015. http://www.nusl.cz/ntk/nusl-227539.

Повний текст джерела

Анотація:

This final thesis deals coucerned with design of heating in the children´s home. The object has basement and three floors. The objectis heated by means of panel and tubular heaters. The heat source (ga condensing boiler) is located in a technical room.

Стилі APA, Harvard, Vancouver, ISO та ін.

7

Nyabadza, Munyaradzi Christine. "Overcoming energy constraints on future development in Stellenbosch through energy efficiency : retrofitting of solar hot water heaters and gas stoves in middle and high income households in the residential sector." Thesis, Stellenbosch : Stellenbosch University, 2012. http://hdl.handle.net/10019.1/20258.

Повний текст джерела

Анотація:

Thesis (MPhil)--Stellenbosch University, 2012.
ENGLISH ABSTRACT: South Africa faces an energy crisis which presents itself in two forms; electricity generation dominated by coal fired power stations and current electricity supply capacity being unable to meet growth in demand. South Africa urgently requires new generation capacity: however, power stations take time to plan, construct and commission, meaning that South Africa has to consider other options to meet electricity demand. This necessitates quick and innovative ways of meeting future demand. Energy efficiency has been identified as “a low hanging fruit” on the energy tree to address supply constraints and reduce energy related greenhouse gas emissions. There are various energy efficiency programmes aimed at raising awareness of measures that households can take to reduce energy consumption. Some of South Africa’s key objectives of energy efficiency in the residential sector are to mitigate the effect of peak demand on power capacity and to introduce state of the art technologies. In terms of these technologies, there is an overlap between energy efficiency and renewable energy. The widespread installation of renewable energy technologies such as SWHs has the potential to delay the need to construct new power stations. SWHs are a viable renewable energy option for South Africa. It is a mature and proven technology with the potential to address South Africa’s electricity capacity problems. Not only does a SWH provide financial savings to the customer in the long run but it offers the additional benefit of a reduction in greenhouse gas emissions to society. Although awareness of the benefits of solar water heaters is increasing, SWH uptake remains low. However the uptake is increasing due to; a SWH rebate offered through Eskom, electricity price increases which are forcing consumers to seek alternatives and a national building code requiring energy efficient water heating in new buildings which is expected to come into effect in 2012. Liquid Petroleum Gas is a low carbon emitting source of fuel for cooking. In South Africa, middle–high income households rely on the electric stove for cooking. Cooking contributes to electricity peak demand. Reducing electricity demand by replacing the electric stove would help in reducing electricity peak demand from the grid. LPG use has been increasing due to the following reasons; electricity supply shortages, shifting government policy on LPG and increasing electricity tariffs forcing lifestyle changes. This case study sought to investigate the opportunities, as well as the barriers for a Stellenbosch municipality - initiated energy efficiency programme. In terms of energy supply and demand management, the municipality has identified energy efficiency and the introduction of renewable energy sources as options for achieving sustainability. One of the barriers facing energy efficient technologies is up-front costs in the case of SWHs and the cost of appropriate equipment such as gas stoves in the case LPG. The study sought to investigate financial mechanisms that the municipality could use to overcome these barriers and promote the use of SWH and gas stove in the residential sector. Data was collected through a combination of a mini Delphi – expert opinion technique, questionnaires, secondary data analysis, telephone and personal interviews with solar water heater industry stakeholders, LPG industry stakeholders and municipal officials. The conclusion drawn from this research is that Stellenbosch Municipality can initiate its own energy efficiency programme instead of waiting for national government. Although the municipality can initiate an energy efficiency programme, it needs to find another institution to fund the programme. Funding mechanisms however do overcome the barrier of high up -front costs and high gas equipment costs making energy efficient technologies affordable.
AFRIKAANSE OPSOMMING: Suid-Afrika staan voor ŉ energiekrisis wat op twee maniere gestalte kry: elektrisiteitsopwekking wat oorheers word deur steenkoolkragstasies en huidige elektrisiteitsvoorsieningsvermoë wat nie in die groeiende aanvraag kan voorsien nie. Suid-Afrika benodig dringend nuwe kragontwikkelingsvermoë. Dit neem egter tyd om kragstasies te beplan, op te rig en in diens te stel, wat beteken dat Suid-Afrika ander opsies moet oorweeg om in elektrisiteitsaanvraag te voorsien. Dit noodsaak vinnige en innoverende maniere om in toekomstige aanvraag te voorsien. Energierendement is as “ŉ laaghangende vrug” op die energieboom geïdentifiseer ten einde beperkings in kragvoorsiening die hoof te bied en kweekhuisgasuitlatings wat met energie verband hou te verminder. Daar is verskeie energiebesparingsprogramme wat ten doel het om die bewustheid te versterk van maatreëls wat huishoudings kan volg om energieverbruik te verminder. Van Suid-Afrika se vernaamste doelstellings ten opsigte van energierendement in die residensiële sektor is om die uitwerking van spitsaanvraag op kragvermoë te verlig en om die jongste tegnologie in te voer. Ingevolge hierdie tegnologieë is daar ŉ oorvleueling tussen energierendement en hernubare energie. Die algemene installering van hernubare energietegnologieë, soos sonkragwaterverwarming (SWV), het die potensiaal om die noodsaaklikheid van die oprigting van nuwe kragstasies uit te stel. SWV is ŉ lewensvatbare nuwe energieopsie vir Suid-Afrika. Dit is ŉ ontwikkelde en bewese tegnologie met die potensiaal om Suid-Afrika se probleme ten opsigte van elektrisiteitsvermoë die hoof te bied. SWV sorg nie slegs vir die kliënt vir finansiële besparing op die lang duur nie, maar dit bied ook vir die samelewing die bykomende voordeel van ŉ afname in kweekhuisgasuitlatings. Alhoewel die bewustheid van die voordele van sonkragwaterverwarming toeneem, bly die gebruik van SWV laag. Die gebruik is egter besig om toe te neem vanweë ŉ SWV-korting wat deur Eskom aangebied word, elektrisiteitsprysverhogings wat verbruikers dwing om alternatiewe te soek, en ŉ nasionale boureglement wat energiedoeltreffende waterverwarming in nuwe geboue vereis en wat na verwagting in 2012 in werking sal tree. Vloeibare petroleumgas is ŉ brandstofbron wat vir kook gebruik word en wat ŉ lae koolstofvrystelling het. In Suid-Afrika gebruik huishoudings met ŉ middelhoë inkomste die elektriese stoof om te kook. Kook dra by tot elektrisiteitspitsaanvraag. Die vermindering in elektrisiteitsaanvraag deur die vervanging van die elektriese stoof kan help om die elektrisiteitspitsaanvraag op die netwerk te verlaag. Die gebruik van VPG het toegeneem weens die volgende redes: elektrisiteitsvoorsieningstekorte, veranderende regeringsbeleid ten opsigte van VPG en die verhoging in elektrisiteitstariewe wat veranderinge in lewenstyl afdwing. Hierdie gevallestudie het gepoog om die geleenthede, sowel as die hindernisse vir ŉ energierendementprogram wat deur Stellenbosch Munisipaliteit geïnisieer is, te ondersoek. Ten opsigte van energievoorsiening en -aanvraagbestuur het die munisipaliteit energierendement geïdentifiseer en die ingebruikneming van hernubare-energiebronne as opsies om volhoubaarheid te bereik. Een van die hindernisse waarvoor energierenderende tegnologieë te staan kom, is voorkostes in die geval van SWV en die koste van toepaslike toerusting soos gasstowe in die geval VPG. Die studie het ondersoek ingestel na die finansiële meganismes wat die munisipaliteit sou kon gebruik om hierdie hindernisse te bowe te kom en die gebruik van SWV en gasstowe in die residensiële sektor te bevorder. Data is ingevorder deur middel van ŉ kombinasie van ŉ mini-Delphi – kennermeningtegniek, vraelyste, sekondêre data-ontleding, telefoon- en persoonlike onderhoude met belanghebbendes in die sonkragwaterverwarmingsbedryf, belanghebbendes in die VPG-bedryf en munisipale amptenare. Die gevolgtrekking wat uit hierdie navorsing gemaak word, is dat Stellenbosch Munisipaliteit sy eie energierendementprogram kan inisieer in plaas daarvan om vir nasionale regering te wag. Alhoewel die munisipaliteit ŉ energierendementprogram kan inisieer, moet dit ŉ ander instelling kry om die program te befonds. Befondsingsmeganismes oorkom egter die struikelblok van hoë voorkostes en hoë kostes van gastoerusting wat energierenderende tegnologieë bekostigbaar maak.

Стилі APA, Harvard, Vancouver, ISO та ін.

8

Lyne, P. M. "Heater displacement chromatography." Thesis, University of Oxford, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.376927.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

9

Slovák, Zdeněk. "Vytápění polyfunkčního objektu." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2014. http://www.nusl.cz/ntk/nusl-226865.

Повний текст джерела

Анотація:

This thesis deals with the design of the heating system in a Polyfunctional building. The design is solving heating of a Polyfunctional Object in Kostelec nad Ohří. The building has basement and two floors. The building is heated by means of panel, tubular and floor convector heaters. The source of the heat is located in the boiler room in the basement.

Стилі APA, Harvard, Vancouver, ISO та ін.

10

Karlgren, Johansson Mikael, and Kevin Leong. "Auxiliary Heater for Natural Gas Trucks." Thesis, Linköpings universitet, Maskinkonstruktion, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-139687.

Повний текст джерела

Анотація:

As alternative fuels are becoming more common, technologies need to adjust to them. Natural gas is one of the alternative fuels that has grown during the latest years in the transport sector. Natural gas consists of around 97 % methane and is the cleanest fossil fuel. The use of natural gas can make it easier to transition to biogas as it has equivalent properties. Today Scania CV AB's trucks fuelled by natural gas are using auxiliary cabin heaters driven by diesel. This means that the natural gas trucks have two fuels on-board the truck. The goal of this project is to find a concept to eliminate the diesel fuel and replace it with an auxiliary cabin heater driven by another energy source. It will improve the heating solution and make it superior from an environmental perspective. The result of the project lead to a short-term solution with an auxiliary heater fuelled by natural gas. A long-term solution is to have a cooperation with a manufacturer to develop a better natural gas auxiliary heater that fulfils more of the requirements in the technical specification. An experiment plan is devised to test parameters out of reach of the project.

Стилі APA, Harvard, Vancouver, ISO та ін.

11

Zanker, Matthew John. "Real gas effects in heated gas inflators." Thesis, University of Iowa, 2010. https://ir.uiowa.edu/etd/768.

Повний текст джерела

Анотація:

Currently, almost all new vehicles are equipped with airbags. A common type of airbag inflator is the Heated Gas Inflator (HGI). These inflators are cylindrical shaped canisters that are filled to very high pressures with a gaseous mixture of fuel and air. The mixture is ignited from one or both ends of the cylinder. The resulting high temperatures from combustion heats the excess air, which is then used to inflate the airbag. Once the mixture is ignited, large pressure waves form, traveling along the length of the tube. These waves, inherent to the design of the inflator, do not allow the use of a volume averaged assumption for the combustion chamber. Therefore, it is necessary to use a Computational Fluid Dynamics (CFD) code to model the dynamic nature of the inflator. Commercial CFD codes are readily available that could be used to model the HGI. These codes use the Ideal Gas Law to calculate the properties of the mixture. The high pressures in an HGI do allow for the use of an ideal gas assumption. Instead, a Real Gas equation of state must be used. An existing Airbag Inflator Model that was capable of Real Gas equation of state calculations had been previously created to simulate solid propellant inflators. In order to properly model the wave dynamics in an HGI and include Real Gas calculations, a CFD model has been added to the Airbag Inflator Model. The CFD model must be capable of handling multiple species of gases and be able to properly model the sharp gradients associated with large pressure waves and changes in chemical species. Therefore, a high-resolution shock capturing technique is used to handle the homogeneous part of the governing equations. The non-homogeneous terms of the governing equations are solved using an ordinary differential equations solver. In order to combine the solutions, a time splitting technique is used to combine the solutions from the homogeneous and non-homogeneous parts of the governing equations. The addition of the CFD model to an Airbag Inflator Model with Real Gas equation of state capabilities provides a very useful tool in the design of HGIs. The model can be used to ensure that a design does not produce unexpected large magnitude pressure waves that could possibly cause dangerous mechanical failures. Later models of HGIs have ignitors at each end of the cylinder. The secondary ignitor can be delayed to vary the production rate of the exhaust gasses, depending on the severity of the crash. This time delay is an additional parameter that can have an effect on the wave dynamics in the HGI. The addition of the CFD model to the Airbag Inflator Model provides a fast and economical way to predict the outcome of any change in the design parameters of an HGI.

Стилі APA, Harvard, Vancouver, ISO та ін.

12

Wesenberg, Margrete Hånes. "Gas Heated Steam Reformer Modelling." Doctoral thesis, Norwegian University of Science and Technology, Department of Chemical Engineering, 2006. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-1627.

Повний текст джерела

Анотація:

Conversion of natural gas is becoming increasingly relevant in the future as the world energy market will demand cleaner fuels, cleaner production of fuels and better utilization of the large, remote, and still undiscovered gas reserves in the world. The refining of the natural gas to synthetic gasoline, diesel and future energy fuels such as methanol and hydrogen is a solution for making the most of these gas reserves.

The intermediate process step in gas refining, the synthesis gas production from natural gas, represents 60–80 % of the total investment cost of a methanol or synthetic fuels plant. This drives the technological development within this process field towards improvements for increasing the efficiency and reducing the costs. The synthetic gas production by steam reforming is a widely used, expensive and energy demanding technology. Steam reformers demand large base areas and are heated by natural gas combustion. Technological developments over the past two decades have lead to an alternative steam reformer, the gas heated reformer, which is a compact unit heated by flue gas or by further converted and heated synthesis gas.

This doctoral thesis is treating the gas heated steam reformer (GHR). The motivation was to develop a complete mathematical model combining of the reactor side and the hot gas side of the reformer and furthermore to investigate the best mathematical descriptions of the heat transport mechanisms involved. The complete model should be as simple as possible but nevertheless be on a level where the important heat transport mechanisms are adequately modelled.

The resulting model is a two-dimensional, finite difference model of a packed bed catalytic tube enclosed by an annular section for counter current flow of the heating gas. The separate partial models, the reactor model and the annulus model, are connected by iterative solution with direct substitution of the temperature and heat flux profiles of the outer reactor tube wall.

The reactor model comes in two versions: a heterogeneous model and a pseudohomogeneous model. The species transport is described by radial dispersion, axial convection and chemical reaction. The heat transport is modelled with terms for radial conduction, axial convection and the heat sink related to the net endothermic reactions.

The annulus model is a simplified plug flow model disregarding the turbulence present. The effect of the turbulent flow on the radial heat transport is still included, by using an effective radial thermal conductivity in the temperature equation. The values for the effective radial thermal conductivities are provided by external simulations in computational fluid dynamics (CFD), where turbulence is modelled by the k-ε turbulence model. The radial heat transport by gas radiation is included by solving the radiative intensity equations by the discrete ordinates method.

The method of importing data for the effective radial thermal conductivity calculated with CFD was evaluated by running test simulations comparable to the CFD simulations. The results showed almost identical axial and radial temperature profiles in the two models when all dissimilarities in the models were allowed for. This simplifying method was thus approved adequate for the purpose.

It was also found that the inclusion of the radial profile of the effective radial thermal conductivity was significant for the overall GHR simulations. Using a mean value for the effective radial thermal conductivity did not result in temperature profiles similar to the profiles of the CFD simulations where turbulence was modelled.

The restrictions related to the mass and heat transport between the gas bulk and the porous pellets were investigated. These resistances are usually neglected in heterogeneous steam reformer modelling based on assumptions that they do not affect the overall reactor simulation results. The heterogeneous reactor model of this thesis includes all pellet transport resistances. Estimations showed that the reaction effectiveness factors, which are defined relative to the pellet surface conditions, were greater than the alternative effectiveness factors defined relative to the bulk conditions. This implies that there exist transport limitations between the two phases. These transport restrictions were found to be of importance when evaluating local effects, as reaction kinetics in general and approach to equilibrium for the coke reactions responsible for catalyst deactivation. On the other hand, the overall reactor simulations were hardly influenced by the interphase transport limitations. This was seen from comparative simulations of the pseudo-homogeneous model using the effectiveness factors and the alternative effectiveness factors. These simulation results were almost equal, while the latter was identical to the results of the heterogeneous model accounting for the resistances.

Стилі APA, Harvard, Vancouver, ISO та ін.

13

Vestlund, Johan. "Gas-filled, flat plate solar collectors." Doctoral thesis, Högskolan Dalarna, Energi och miljöteknik, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:du-6182.

Повний текст джерела

Анотація:

This work treats the thermal and mechanical performances of gas-filled, flat plate solar collectors in order to achieve a better performance than that of air filled collectors. The gases examined are argon, krypton and xenon which all have lower thermal conductivity than air. The absorber is formed as a tray connected to the glass. The pressure of the gas inside is near to the ambient and since the gas volume will vary as the temperature changes, there are potential risks for fatigue in the material. One heat transfer model and one mechanical model were built. The mechanical model gave stresses and information on the movements. The factors of safety were calculated from the stresses, and the movements were used as input for the heat transfer model where the thermal performance was calculated. It is shown that gas-filled, flat plate solar collectors can be designed to achieve good thermal performance at a competitive cost. The best yield is achieved with a xenon gas filling together with a normal thick absorber, where normal thick means a 0.25 mm copper absorber. However, a great deal of energy is needed to produce the xenon gas, and if this aspect is taken into account, the krypton filling is better. Good thermal performance can also be achieved using less material; a collector with a 0.1 mm thick copper absorber and the third best gas, which is argon, still gives a better operating performance than a common, commercially produced, air filled collector with a 0.25 mm absorber. When manufacturing gas-filled flat plate solar collectors, one way of decreasing the total material costs significantly, is by changing absorber material from copper to aluminium. Best yield per monetary outlay is given by a thin (0.3 mm) alu-minium absorber with an argon filling. A high factor of safety is achieved with thin absorbers, large absorber areas, rectangular constructions with long tubes and short distances between glass and absorber. The latter will also give a thin layer of gas which gives good thermal performance. The only doubtii ful construction is an argon filled collector with a normal thick (> 0.50 mm) aluminium absorber. In general, an assessment of the stresses for the proposed construction together with appropriate tests are recommended before manufacturing, since it is hard to predict the factor of safety; if one part is reinforced, some other parts can experience more stress and the factor of safety actually drops.

Стилі APA, Harvard, Vancouver, ISO та ін.

14

Wang, Hao. "The effect of primary air distribution on emissions from a natural gas water heater." Marquette University, 2013.

Знайти повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

15

Paták, Jiří. "Hydraulika otopných soustav." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2013. http://www.nusl.cz/ntk/nusl-226013.

Повний текст джерела

Анотація:

The theoretical part deal with problematic of fluid power heating system. The experimental part deal with measurement of the characteristic of circulation pump and measurement of valves - ball valve. The project solves the heating and hot water preparing for the new administrative building in Žďár nad Sázavou. The building has 3 floors. As a source of heat for the winter season is designed gas boiler, for hot water preparing is also used the same gas boiler. The heat source is placed in a separately accessible room.

Стилі APA, Harvard, Vancouver, ISO та ін.

16

Yang, Anthony Yuan-Jung. "Effect of heater type on CO/CO2 concentrations in a farrowing barn." Thesis, University of Iowa, 2015. https://ir.uiowa.edu/etd/1939.

Повний текст джерела

Анотація:

Clear evidence shows a relationship between working in swine facilities and developing respiratory illnesses. Health effects have been associated with exposures to the combination of dust, ammonia, and carbon dioxide (CO2). This study examined whether room concentrations of combustion gases could be improved by changing the in-room vented heaters common to animal production operations to heaters that vent combustion gases outside. Concentrations of CO2 and carbon monoxide (CO) were monitored during two winter seasons, with the 2013-14 season using the traditional gas-fired heater (Guardian 60, L.B.White Co.) and the 2014-15 winter using new vented heaters (Effinity93, Modine Manufacturing Co.) Direct-reading CO (VRAE, Rae Systems) and CO2 (ToxieRAE Pro, Rae Systems) monitors were deployed at fixed stations throughout the farrowing barn to measure gas concentrations. Differences in mean gas concentrations between heater types, as well as the relationship between CO2 and temperature, sow, and piglet count, were evaluated using linear regression. Carbon dioxide concentrations exceeded industry recommended limits (1540 ppm) on all sample days (N=18) with the standard in-room vented heaters in operation: concentrations averaged half of the TLV (2500 ppm). With the new vented heaters, 24-hour averaged CO2 concentrations exceeded industry recommended limits on only three out of 20 sample days: concentrations averaged 1400 ppm. The new heater significantly reduced CO2 by 44% and CO by 60% from 2.0 to 0.8 ppm (p2=0.75) between CO2 and production factors (temperature, sow and piglet count) for the new heater: CO2 (ppm) = 482 - 22.4(Temp °C) + 43(# sow) + 5.6(# piglet). Similar analysis for the old heater identified similar trends but substantially different intercept (1700 ppm) and temperature factor (-36.9). While CO2 is still generated from swine respiration, we found significant reductions in room concentrations with the simple replacement of commonly used equipment. Future work will include an assessment of the longevity of these heaters in the swine barn environment

Стилі APA, Harvard, Vancouver, ISO та ін.

17

O’Dea, C. P., D. M. Worrall, G. R. Tremblay, T. E. Clarke, B. Rothberg, S. A. Baum, K. P. Christiansen, C. A. Mullarkey, J. Noel-Storr, and R. Mittal. "Testing for Shock-heated X-Ray Gas around Compact Steep Spectrum Radio Galaxies." IOP PUBLISHING LTD, 2017. http://hdl.handle.net/10150/626415.

Повний текст джерела

Анотація:

We present Chandra and XMM-Newton X-ray, Very Large Array (VLA) radio, and optical observations of three candidate compact steep spectrum (CSS) radio galaxies. CSS sources are of a galactic scale and are presumably driving a shock through the interstellar medium (ISM) of their host galaxy. B3 1445+410 is a low-excitation emission line CSS radio galaxy with possibly a hybrid Fanaroff-Riley FRI/II (or fat double) radio morphology. The Chandra observations reveal a point-like source that is well fit with a power law consistent with the emission from a Doppler boosted core. 3C 268.3 is a CSS broad-line radio galaxy (BLRG) whose Chandra data are consistent spatially with a point source centered on the nucleus and spectrally with a double power-law model. PKS B1017-325 is a low-excitation emission line radio galaxy with a bent double radio morphology. While from our new spectroscopic redshift, PKS B1017-325 falls outside the formal definition of a CSS, the XMM-Newton observations are consistent with ISM emission with either a contribution from hot shocked gas or non-thermal jet emission. We compile selected radio and X-ray properties of the nine bona fide CSS radio galaxies with X-ray detections so far. We find that two out of the nine show X-ray spectroscopic evidence for hot shocked gas. We note that the counts in the sources are low and that the properties of the two sources with evidence for hot shocked gas are typical of the other CSS radio galaxies. We suggest that hot shocked gas may be typical of CSS radio galaxies due to their propagation through their host galaxies.

Стилі APA, Harvard, Vancouver, ISO та ін.

18

Jára, Marek. "Vytápění bytového domu." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2020. http://www.nusl.cz/ntk/nusl-409867.

Повний текст джерела

Анотація:

The theme of this diploma thesis is to design heating of the flat house. The theoretical part of this diploma thesis is about exhaust gases paths. The calculation part of this diploma thesis contains the design of the heating system by panel heaters, floor convectors and underfloor heating system. The heat source is the system of cascade-connected gas condensing boilers. The rest of this part are the calculations of the preparation of hot water, design of hot water storage tank and another necessary equipment of the system. The part Project is about technical report and simulation of behaviour of underfloor heating system in various marginal conditions.

Стилі APA, Harvard, Vancouver, ISO та ін.

19

Dunne, Anthony Michael. "Measurements of thermal and radiation energy transport in laser and soft X-ray heated targets." Thesis, Imperial College London, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.336433.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

20

Lione, Richard. "The study of heats of adsorption of gases of thin organic films using a novel interferometric micro-calorimeter." Thesis, University of Kent, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.358168.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

21

Lee, Jeongik. "Gas heat transfer in a heated vertical channel under deteriorated turbulent heat transfer regime." Thesis, Massachusetts Institute of Technology, 2007. http://hdl.handle.net/1721.1/41296.

Повний текст джерела

Анотація:

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Nuclear Science and Engineering, 2007.
Includes bibliographical references (p. 283-289).
Passive cooling via natural circulation of gas after a loss of coolant (LOCA) accident is one of the major goals of the Gas-cooled Fast Reactor (GFR). Due to its high surface heat flux and low coolant velocities under natural circulation in post-LOCA scenarios, the capability of turbulent gas flow to remove heat from the GFR core can be impaired by either a buoyancy effect or an acceleration effect. These phenomena lead to a Deteriorated Turbulent Heat Transfer (DTHT) regime. To predict accurately the cladding temperature at the hot spot, reliable heat transfer correlations that account correctly for these effects are needed. This work addresses this need by experimentally obtaining heat transfer data and developing new heat transfer correlations that can be used in system analysis codes, such as RELAP5-3D, to reduce uncertainties of predictions in these DTHT regimes. An experimental facility was designed and built using similitude analysis to match key experimental loop parameters to the GFRs' Decay Heat Removal (DHR) system operating conditions to the largest extent possible. Through a thorough literature survey two non-dimensional numbers namely (1) the buoyancy parameter (Bo*) and (2) the acceleration parameter (K,) were identified as important indicators of the DTHT regime. The experimental data was collected for a range of (1) inlet Reynolds number from 1800 to 42,700, (2) inlet Bo* up to 1X10-5 (3) and inlet Kv up to 5x10-6. The data showed significantly higher reduction of the Nusselt number (up to by 70%) than previously reported (up to 50%). Also, the threshold at which DTHT regime occurs was found to be at smaller non-dimensional numbers than previously reported. A new phenomenon "re-turbulization", where the laminarized heat transfer recovers back to turbulent flow along the channel, was observed in the experiment.
(cont.) A new single phase gas flow heat transfer map is proposed based on the non-dimensional heat flux and the Reynolds number in our data, and is shown to compare well with data in the literature. Three sets of new correlations were developed, which reflect both the buoyancy and acceleration effects and have better accuracy as well as ease of numerical implementation than the existing correlations. The correlations are based on the Gnielinski correlation and replace the Reynolds number subtracting constant by a functional form that accounts for the buoyancy and acceleration effects separately, or in the combined form through a newly introduced non-dimensional "DTHT" number. The three correlation types have different complexity level, with the first being the most complex and the third being the most simple and easy to apply without any need for iterations. Additional runs with natural circulation showed that the friction factor in the DTHT regime could be significantly higher than predicted by conventional friction factor correlations, although more experiments will be needed to develop reliable correlations for pressure drop in these regimes. Overall, it is concluded that due to the low heat transfer coefficient and increased friction factor in the DTHT regime, the GFR DHR system should be ideally designed to operate outside the DTHT regime to (1) avoid reduction of heat transfer capability, (2) avoid increase of pressure drop, and (3) reduce uncertainties in predictions of the cladding temperature.
by Jeongik Lee.
Ph.D.

Стилі APA, Harvard, Vancouver, ISO та ін.

22

Nelson, Edward L. "Temperature, pressure, and infrared image survey of an axisymmetric heated exhaust plume." Diss., This resource online, 1994. http://scholar.lib.vt.edu/theses/available/etd-06062008-171052/.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

23

Mahdavifar, Alireza. "Computational and experimental development of ultra-low power and sensitive micro-electro-thermal gas sensor." Diss., Georgia Institute of Technology, 2015. http://hdl.handle.net/1853/54923.

Повний текст джерела

Анотація:

In this research a state-of-the-art micro-thermal conductivity detector is developed based on MEMS technology. Its efficient design include a miniaturized 100×2 µm bridge from doped polysilicon, suspended 10 µm away from the single crystalline silicon substrate through a thermally grown silicon dioxide sacrificial layer. The microbridge is covered by 200 nm silicon nitride layer to provide more life time. Analytical models were developed that describe the relationship between the sensor response and ambient gas material properties. To obtain local temperature distribution and accurate predictions of the sensor response, a computational three dimensional simulation based on real geometry and minimal simplifications was prepared. It was able to handle steady-state and transient state, include multiple physics such as flow, heat transfer, electrical current and thermal stresses. Two new methods of measurement for micro TCD were developed; a time resolved method based on transient response of the detector to a step current pulse was introduced that correlates time constant of the response to the concentration of gas mixture. The other method is based on AC excitation of the micro detector; the amplitude and phase of the third harmonic of the resulting output signal is related to gas composition. Finally, the developed micro-sensor was packaged and tested in a GC system and was compared against conventional and complex FID for the detection of a mixture of VOCs. Moreover compact electronics and telemetry modules were developed that allow for highly portable applications including microGC utilization in the field.

Стилі APA, Harvard, Vancouver, ISO та ін.

24

Baril-Gosselin, Simon. "Improving Integrally Heated Composite Tooling Through Cold Sprayed Copper Coatings and Heat Transfer Simulations." Thèse, Université d'Ottawa / University of Ottawa, 2013. http://hdl.handle.net/10393/24237.

Повний текст джерела

Анотація:

Integrally heated composite tooling (IHCT) is seen as a low cost alternative to autoclave manufacturing of polymer matrix composites (PMCs). IHCTs consist of a composite tool heated by surface heaters; temperature distribution is ensured by a thermally conductive metallic layer. The main original contributions of this thesis was the development of a new method for applying copper coatings onto carbon fibre/epoxy PMCs using pulsed gas dynamic spraying, the production of larger size samples, and the characterisation of the performance of the coatings and laminates obtained. It was shown that this method has potential for producing the thermally conductive layer in an IHCT. Another contribution was the characterisation of parameters affecting temperature distribution across IHCTs through heat transfer simulations, leading to guidelines for IHCT design.

Стилі APA, Harvard, Vancouver, ISO та ін.

25

Ruales, Mary Cristina. "Design of a Low Power – High Temperature Heated Ceramic Sensor to Detect Halogen Gases." FIU Digital Commons, 2007. http://digitalcommons.fiu.edu/etd/33.

Повний текст джерела

Анотація:

The design, construction and optimization of a low power-high temperature heated ceramic sensor to detect leaking of halogen gases in refrigeration systems are presented. The manufacturing process was done with microelectronic assembly and the Low Temperature Cofire Ceramic (LTCC) technique. Four basic sensor materials were fabricated and tested: Li2SiO3, Na2SiO3, K2SiO3, and CaSiO3. The evaluation of the sensor material, sensor size, operating temperature, bias voltage, electrodes size, firing temperature, gas flow, and sensor life was done. All sensors responded to the gas showing stability and reproducibility. Before exposing the sensor to the gas, the sensor was modeled like a resistor in series and the calculations obtained were in agreement with the experimental values. The sensor response to the gas was divided in surface diffusion and bulk diffusion; both were analyzed showing agreement between the calculations and the experimental values. The sensor with 51.5%CaSiO3 + 48.5%Li2SiO3 shows the best results, including a stable current and response to the gas.

Стилі APA, Harvard, Vancouver, ISO та ін.

26

af, Klintberg Tord. "Heated air gaps : a possibility to dry out dampness from building constructions." Licentiate thesis, KTH, Civil and Architectural Engineering, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-9490.

Повний текст джерела

Анотація:

The air gap method is a modification of the common way of building indoor walls and floors. The aim of the method is to make a construction, less fragile to water damage, with air gaps where moisture can be removed with a thermally driven air flow, caused by a heating cable. The thesis includes a number of experimental studies of this method.

Temperature and convective air flow in a vertical air gap was studied and it was noted how air flow increased with raised power of the heating cable. The air flow for one meter of wall varied between 50 m3/day (13 air changes per hour) and 140 m3/day (36 air changes per hour). The lower value was caused by a temperature difference in the range 0.2-0.3 oC. Without heating no air flow was found.

In studies of moisture and RH in wet “slab on ground” constructions, it was noted how the slab in the room with the air gap method dried to a much higher extent than the slab in the room built in an ordinary way. It was also noted that moisture was transported from the air gap in the floor and up through the air gap in the wall. In the room with the air gap construction, the RH values beneath the floor was at a lower level (and below 75 % RH) than the RH values beneath the floor of conventional construction. Mould does not grow below 75 % RH.

In the study of a flooded intermediate floor it was noted how the thermally driven convective air flow evidently speeded up drying of the construction. Mould growth was only noted in the case where the heating cables were turned off.

Spaltmetoden är en modifiering av det reguljära sättet av att bygga innerväggar och bjälklag. Syftet med metoden är att skapa en byggnadskonstruktion som är mindre skör med avseende på fuktskador. Detta görs med spalter där fukt kan avlägsnas genom ett termiskt drivet luftflöde som orsakas av en värmekabel. Denna avhandling innehåller ett antal experimentella studier på metoden. Spaltmetoden har studerats med avseende på 1. Samband mellan temperatur och luftflöde, 2. Uttorkning och RF nivåer i golvkonstruktioner samt 3. Översvämning av ett mellanbjälklag

1. Samband mellan temperatur och luftflöde

Temperatur och konvektivt luftflöde har studerats i en vertikal spalt och resultatet visar att luftflödet ökar med ökad effekt hos värmekabeln. Luftflödet i en vägg med en meters bredd varierade mellan 50 kubikmeter/dag (13 luftväxlingar per timme) och 140 kubikmeter/dag (36 luftväxlingar per timme). Det lägre flödet orsakades av en temperaturskillnad på 0,2-0,3 oC mellan luftspalt och rum. När värmekabeln var avstängd så registrerades inget luftflöde.

2. Uttorkning och RF nivåer i golvkonstruktioner ovan betongplatta

Detta experiment visade att fukt har transporterats från spalten i golvet genom spalten i väggen ut i rumsluften. I spaltkonstruktion var RF inuti golvkonstruktionen lägre (och understeg 75 % RF), jämfört med den konventionella konstruktionen, (mögel växer inte under 75 % RF). Det har också registrerats att betongplattan som hörde till spaltmetoden torkade ut snabbare än betongplattan som var inbyggd i ett gängse rum.

3. Översvämning av ett mellanbjälklag

I studien där ett mellanbjälklag blev översvämmat noterades att spaltmetoden förkortade torktiden från 21 dagar till 13 vid den fuktigaste mätpunkten. Mögelväxt noterades endast då värmekabeln hade varit frånslagen.

Стилі APA, Harvard, Vancouver, ISO та ін.

27

Juránková, Kristýna. "Využití alternativních paliv ve vytápění budov." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2016. http://www.nusl.cz/ntk/nusl-240466.

Повний текст джерела

Анотація:

The aim of the diploma thesis "The use of alternative fuels in heating buildings " is the application of the heat sources using alternative fuels for heating of the production hall. The source of heat is a gas boiler, wood chips and dark gas infrared heaters. Appliances are then convection heaters, tubular registers and hot-air units.

Стилі APA, Harvard, Vancouver, ISO та ін.

28

Junior, Jose Jorge Chaguri. "Sistemas prediais de aquecimento de água a gás: Parâmetros de dimensionamento e gerenciamento." Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/86/86131/tde-26082009-092455/.

Повний текст джерела

Анотація:

Os sistemas prediais de aquecimento de água são responsáveis por uma parcela significativa no consumo de energia do país, sendo que a eficiência do uso desta energia está relacionada com a qualidade dos projetos e de alternativas construtivas que possibilitam racionalizar o uso dos recursos naturais. Com a tendência de incorporação da medição individualizada de água e do aquecimento solar, algumas concepções de projetos hidráulicos foram alteradas, entre elas, a introdução de sistemas centrais coletivos de aquecimento de água no setor residencial. Porém, os métodos de dimensionamento destes sistemas são restritos à determinação do estado estático da infraestrutura e dos equipamentos envolvidos. Conhecendo as características de uso da população é possível introduzir sistemas de monitoração e gestão que alterem o dimensionamento das centrais de aquecimento, conforme a demanda instantânea, gerando reduções de perdas térmicas. Este trabalho consiste em analisar as variáveis de um sistema predial de aquecimento central a gás e o impacto na implantação de sistemas de monitoração e gestão.
The building systems of water heating are responsible for a significant parcel of energy consumption in country, and the efficiency of use of this energy is related to the quality of projects and constructive alternatives that allow rationalizing the use of natural resources. With the trend of incorporating the measurement of individual water and solar heating, some conceptions of hydraulic projects were changed including the introduction of collective central heating water in the residential sector. However, the methods of these systems are restricted to the determination of the static state of infrastructure and equipment involved. Knowing the characteristics of populations use is possible to introduce systems of monitoring and management to change the design of central heating as the instant demand, causing reductions in thermal losses.

Стилі APA, Harvard, Vancouver, ISO та ін.

29

Zabeti, Jahromi Siavash [Verfasser], and Christof [Akademischer Betreuer] Schulz. "Optical properties and reaction kinetics of shock-heated gas-phase tracers for quantitative laser-induced fluorescence / Siavash Zabeti Jahromi ; Betreuer: Christof Schulz." Duisburg, 2019. http://d-nb.info/1193590906/34.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

30

Marati, Jagannath Rao [Verfasser], Tatiana [Akademischer Betreuer] Gambaryan-Roisman, Peter [Akademischer Betreuer] Stephan, and Cameron [Akademischer Betreuer] Tropea. "Two-Phase CFD Simulation of Turbulent Gas-Driven Liquid Film Flows on Heated Walls / Jagannath Rao Marati. Betreuer: Tatiana Gambaryan-Roisman ; Peter Stephan ; Cameron Tropea." Darmstadt : Universitäts- und Landesbibliothek Darmstadt, 2016. http://d-nb.info/1112268944/34.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

31

Micius, Darius. "Infraraudonųjų spindulinių šildytuvų tyrimas." Master's thesis, Lithuanian Academic Libraries Network (LABT), 2010. http://vddb.laba.lt/obj/LT-eLABa-0001:E.02~2010~D_20100618_134444-78625.

Повний текст джерела

Анотація:

Tiriamojo darbo tikslas – ištirti spindulinio dujinio šildytuvo darbo režimo parametrus. Dujinis spindulinis šildymas yra ekonomiška, nekenksminga ir labai paprasta šildymo sistema. Tokia šildymo sistema naudojama patalpose su blogu sandarumu, taip pat kur yra dideli aukščiai. Tirtas ,,U‘‘ formos spindulinis dujinis šildytuvas. Tyrinėtos šiluminės savybės spindulinio šildytuvo paviršiaus, kaitimo savybės vamzdžio skirtinguose šildytuvo pjūviuose, vamzdžio įšilimo trukmė, galia šildytuvo, dujų sunaudotas kiekis. Spindulinis dujinis šildymas Lietuvoje mažai ištirtas.
Purpose of work: the research working mode of processed „U“ form radial gas–fired heater. The gas-fired heating is an economical, ecological, harmless and very simply heating system. Such heating system is used in the accommodations with high sealing and there are big height. Were processeded „U“ form radial gas–fired heater. Were explored heating dynamics of radial heater culvert surface, dynamics changing of culvert temperature in characteristic heater operating length section, duration till culvert heats to operating temperature, capacity of processed heater, the gas amount. The radial heating in Lithuanian is few processed and very heavy to do concrete conclusion.

Стилі APA, Harvard, Vancouver, ISO та ін.

32

Drábek, Ivo. "Energetický zdroj se spalovací turbinou." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2012. http://www.nusl.cz/ntk/nusl-230039.

Повний текст джерела

Анотація:

The goal of this master´s thesis is designing power plant with gas turbine of 50 MWe power output for the site. It includes appropriete choose of gas turbine and its simplified termodynamic calculation, designing the thermal diagram and its calculation, for the parameters complying with nominal temperature of outside air, layout design, annual energy and mass flow results, savings of combined heat and power, intended at this application and economic evaluation of investment.

Стилі APA, Harvard, Vancouver, ISO та ін.

33

Dohnal, Jakub. "Kotel na spoluspalovaní vysokopecního plynu a koksárenského plynu." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2016. http://www.nusl.cz/ntk/nusl-242878.

Повний текст джерела

Анотація:

This diploma thesis deals with the constructional and calculation design of boiler for blast furnace and coke gas mixture combustion, including sizing of the heating surfaces. The opening section is dedicated to a brief characterization of burned fuels. The following chapter shows the parameters and composition of the resulting fuel mixture. The main part of this thesis involves; determining the stoichiometric amount air required for combustion and the resulting flue gas, determining the boiler efficiency and steam production rate, calculations regarding the combustion chamber and the detailed design of the individual heat exchangers. At the end of the thesis the heat balance of the entire boiler is verified. Drawing documentation of boiler is also part of this diploma thesis.

Стилі APA, Harvard, Vancouver, ISO та ін.

34

Cairns, Amy J. "Structural Diversity in Crystal Chemistry: Rational Design Strategies Toward the Synthesis of Functional Metal-Organic Materials." Scholar Commons, 2010. http://scholarcommons.usf.edu/etd/3455.

Повний текст джерела

Анотація:

Metal-Organic Materials (MOMs) represent an important class of solid-state crystalline materials. Their countless attractive attributes make them uniquely suited to potentially resolve many present and future utilitarian societal challenges ranging from energy and the environment, all the way to include biology and medicine. Since the birth of coordination chemistry, the self-assembly of organic molecules with metal ions has produced a plethora of simple and complex architectures, many of which possess diverse pore and channel systems in a periodic array. In its infancy however this field was primarily fueled by burgeoning serendipitous discoveries, with no regard to a rational design approach to synthesis. In the late 1980s, the field was transformed when the potential for design was introduced through the seminal studies conducted by Hoskins and Robson who transcended the pivotal works of Wells into the experimental regime. The construction of MOMs using metal-ligand directed assembly is often regarded as the origin of the molecular building block (MBB) approach, a rational design strategy that focuses on the self-assembly of pre-designed MBBs having desired shapes and geometries to generate structures with intended topologies by exploiting the diverse coordination modes and geometries afforded by metal ions and organic molecules. The evolution of the MBB approach has witnessed tremendous breakthroughs in terms of scale and porosity by simply replacing single metal ions with more rigid inorganic metal clusters whilst preserving the inherent modularity and essential geometrical attributes needed to construct target networks for desired applications. The work presented in this dissertation focuses upon the rational design and synthesis of a diverse collection of open frameworks constructed from pre-fabricated rigid inorganic MBBs (i.e. [M(CO2)4], [M2(RCO2)4], [M3O(RCO2)6], MN3O3, etc), supermolecular building blocks (SBBs) and 3-, 4- and 6-connected organic MBBs. A systematic evaluation concerning the effect of various structural parameters (i.e. pore size and shape, metal ion, charge, etc) on hydrogen uptake and the relative binding affinity of H2-MOF interactions for selected systems is provided.

Стилі APA, Harvard, Vancouver, ISO та ін.

35

Strnad, Ondřej. "Roštový kotel na spalování dřevní štěpky - 96,4 t/h." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2020. http://www.nusl.cz/ntk/nusl-417550.

Повний текст джерела

Анотація:

This thesis deals with issue of grate boilers. It describes their properties, function principles and usage. The main part of this thesis is design of grate boiler burning biomass with steam output 96.4 tons/hour. Steam temperature and pressure at the output are 490 °C and 8.1 MPa.

Стилі APA, Harvard, Vancouver, ISO та ін.

36

Koch, David R. "Field and laboratory application of a gas chromatograph low thermal mass resistively heated column system in detecting traditional and non-traditional chemical warfare agents using solid phase micro-extraction /." Download the thesis in PDF, 2005. http://www.lrc.usuhs.mil/dissertations/pdf/Koch2005.pdf.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

37

Matějková, Lucie. "Zdravotně technické a plynovodní instalace v penzionu." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2017. http://www.nusl.cz/ntk/nusl-265658.

Повний текст джерела

Анотація:

The Diploma thesis contains design of plumbing and gas installations in a pension. The theory solves warming of water, ways of warming, and dimensioning according to ČSN 06 0320. The calculation part solves variants of hot water preparations and installations of sewerage water. The practical part contains a design and a projekt of plumbing and gas installations.

Стилі APA, Harvard, Vancouver, ISO та ін.

38

Aguiar, Iraldo Belchior Cristino. "Aquecedor Poroso com Sistema de IgniÃÃo LanÃa-Chama Aplicado ao GÃs Natural e ao BiogÃs." Universidade Federal do CearÃ, 2010. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=5693.

Повний текст джерела

Анотація:

CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior
A âCombustÃo de FiltraÃÃoâ Ã uma tecnologia que tem sido empregada no desenvolvimento de aquecedores e caldeiras de alta eficiÃncia e baixa emissÃo de poluentes. No entanto, o processo de igniÃÃo da combustÃo nesses equipamentos, constituÃdos de queimadores porosos volumÃtricos, tem sido ainda uma questÃo nÃo resolvida. Os sistemas convencionais desenvolvidos para esses queimadores apresentam algum inconveniente operacional que prejudica a eficiÃncia de combustÃo. EntÃo, este trabalho tem como objetivo principal apresentar um projeto robusto e econÃmico de sistema de igniÃÃo por lanÃa-chamas destinado a queimadores porosos volumÃtricos, em que a CombustÃo de FiltraÃÃo estÃ sendo aplicada como tecnologia de base para desenvolvimento de um novo modelo de aquecedor de Ãgua. Um protÃtipo do aquecedor equipado com o sistema de igniÃÃo foi desenvolvido, em escala de laboratÃrio, realizando-se estudos experimental e teÃrico quanto Ã queima com gÃs natural e com biogÃs. A anÃlise teÃrica envolve a caracterizaÃÃo do escoamento dos gases ao longo do corpo do sistema de igniÃÃo atravÃs da simulaÃÃo com o software âANSYS-CFXâ, como tambÃm, dos fenÃmenos relacionados Ã onda de combustÃo propagando-se no queimador do aquecedor, para o qual foi utilizado um modelo numÃrico de simulaÃÃo em FORTRAN. Neste contexto, Ã utilizado o software PREMIX no cÃlculo de equilÃbrio quÃmico, aplicÃvel Ã combustÃo prÃ-misturada em um meio poroso, tomando como referÃncia os dois parÃmetros principais de operaÃÃo: a razÃo de equivalÃncia e a velocidade do escoamento da mistura ar-combustÃvel. Como resultado: o sistema de igniÃÃo proposto mostrou-se adequado aos queimadores porosos, provendo estabilidade e facilidade de operaÃÃo, e reduzindo significativamente o tempo necessÃrio ao prÃ-aquecimento do meio poroso. O modelamento do escoamento e da combustÃo serviu de suporte para interpretaÃÃo adequada dos fenÃmenos presentes nos processos. A CombustÃo de FiltraÃÃo possibilitou a operaÃÃo estÃvel do aquecedor em ampla faixa de razÃo de equivalÃncia (de 0.30 a 1).
"Filtration Combustion" is a technology that has been used in the development of heaters and boilers with high efficiency and low pollutant emissions. However, the ignition process of combustion in such equipments, constituted of volumetric porous burners, have been an issue still unresolved. Conventional systems developed for these burners present some operational drawback that affects the combustion efficiency. So, this work aims mainly to present a robust and economical design of flame-thrower ignition system aimed at volumetric porous burners, in which Filtration Combustion is being applied as a basis technology for the developing a new model of water heater. A prototype of the heater equipped with the ignition system has been developed in laboratory scale, carrying out experimental and theoretical studies on the burning natural gas and biogas. The theoretical analysis involves the characterization of gas flow along the body of the ignition system through simulation with the software "ANSYS-CFX," as well as of the phenomena related to the combustion wave propagating itself through the heaterâs burner, for which a numerical simulation in FORTRAN has been used. In this context, a software âPREMIXâ was used in the chemical equilibrium calculation, applicable to premixed combustion in a porous medium, taking as reference the two main parameters of operation: the equivalence ratio and flow velocity of the air-fuel mixture. As a result, the ignition system proposed has been adequate to the porous burner, providing stability and ease of operation, and significantly reducing the time required for preheating the porous medium. The modeling of flow and combustion has served as a support for proper interpretation of the phenomena present in the processes. Filtration Combustion has allowed stable operation of the heater in a wide range of equivalence ratio (from 0.30 to 1).

Стилі APA, Harvard, Vancouver, ISO та ін.

39

Soucasse, Laurent. "Effets des transferts radiatifs sur les écoulements de convection naturelle dans une cavité différentiellement chauffée en régimes transitionnel et faiblement turbulent." Phd thesis, Ecole Centrale Paris, 2013. http://tel.archives-ouvertes.fr/tel-00978507.

Повний текст джерела

Анотація:

Les effets des transferts radiatifs sur les écoulements de convection naturelle sont étudiés en régimes transitionnel et turbulent. On considère des mélanges air/H2O/CO2 confinés dans des cavités cubiques différentiellement chauffées. Des simulations numériques de référence sont entreprises jusqu'à Ra=3x108 en couplant une méthode spectrale de collocation pour l'écoulement et une méthode de lancer de rayons, associée à un modèle ADF, pour le rayonnement. Pour l'étude du régime turbulent, une modélisation des transferts radiatifs basée sur un filtrage spatial est proposée : les contributions filtrées sont résolues par la méthode de lancer de rayons sur un maillage lâche et les contributions de sous-maille sont résolues de manière analytique dans l'espace de Fourier. Ce modèle est combiné à la simulation numérique directe de l'écoulement à Ra=3x109. Les transferts radiatifs ont pour effet de diminuer la stratification thermique verticale et d'augmenter la circulation générale. Lorsque les six parois de la cavité sont noires et le gaz transparent, deux zones de stratification thermique instable apparaissent en amont des couches limites verticales. Dès Ra=5x106, une instabilité de type Rayleigh-Bénard se développe dans ces zones, induisant des écoulements instationnaires. Lorsque les parois adiabatiques sont parfaitement réfléchissantes, les parois isothermes noires et le gaz rayonnant, des écoulements instationnaires chaotiques sont obtenus à partir de Ra=3x107. Des rouleaux contra-rotatifs à la sortie des couches limites verticales sont observés, ce qui suggère qu'une instabilité de force centrifuge soit responsable de la transition.

Стилі APA, Harvard, Vancouver, ISO та ін.

40

Lin, Chia-Ming, and 林家銘. "The Study for Solar Water Heating System Applied for Constant Temperature Gas Water Heaters." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/mzcmkk.

Повний текст джерела

Анотація:

碩士
國立臺北科技大學
自動化科技研究所
98
Being the most commonly home-used heating resources for water heaters, new energy apart from gas has been also the most concerned issue due to the air pollution and green-house effect. To lowering down the energy consumption, this study has applied the solar energy as heating assistance for water heating system. By utilizing the solar energy, connecting directly to constant gas water heaters and equipping one sensor in the water inlet. When there has higher temperature detected in the water inlet by sensor, the stored hot water that was heated by solar will be applied to save the energy. When there has lower temperature detected, the gas water heaters will be started automatically to heat up the water in order to supply the insufficient heat and control the water temperature as well. In the article, firstly the characteristic and principle for both heat-colleting board and constant gas water heater are being analyzed. And by serial installation of them to proceed with the experiment. Also the embedded system has been combined together with RF transmitting. The RF module is installed indoor to control the same that is installed outdoor in the water heater part for conveniently setting the temperature. This study has also using the UART interface to receiving the transmitting data in observing the working of the water heaters and proving the system is capable in efficiently working.

Стилі APA, Harvard, Vancouver, ISO та ін.

41

Nitschke, Monika. "Randomised controlled trial investigating the effects of nitrogen dioxide in classrooms on the respiratory health of asthmatic primary school children." Thesis, 2002. http://hdl.handle.net/2440/73201.

Повний текст джерела

Анотація:

A study to determine the effects of a randomised controlled trial of unflued gas heater replacement on asthma in children. 18 schools using unflued gas heaters in winter were randomly allocated an intervention of heater replacement with either flued gas heaters, or electric, or remained unflued. The main eligibility criteria were doctor-diagnosed asthma with no unflued gas sources at home (a priori sample). The sample was extended to asthmatic children with home gas cooking. Participants kept a daily diary of symptoms for 12 weeks in order to establish symptom rates in the intervention and control groups. Indoor NO₂ was monitored in classrooms and homes during the study period. In the a priori sample, difficulty breathing, chest tightness and asthma attack rates were significantly decreased in the intervention group compared to the control group. In the extended group, symptom rates were not significantly different. Reduced NO₂ levels in classrooms were accompanied by more than a 50% reduction in some asthmatic symptoms in the intervention a priori group.
Thesis (Ph.D.) -- University of Adelaide, Dept. of Medicine, 2002

Стилі APA, Harvard, Vancouver, ISO та ін.

42

Singh, Inderjit. "Gas Sensors - Micro-Heater Designs And Studies On Sensor Film Deposition." Thesis, 2006. http://hdl.handle.net/2005/393.

Повний текст джерела

Анотація:

Current gas sensor technology, although meeting the minimum requirements in many instances, suffers for a number of limitations. Hence, there is currently a considerable volume of research being undertaken at many laboratories of different countries. In the past, all chemical sensors and catalyst were optimized empirically by a trial and error method. Today, however, systematic research and development is becoming increasingly important in order to improve sensors and to find new sensing principles. Obtaining a long term stable gas sensor with improved sensitivity, selectivity, and low cost for mass production passes through fundamental research and material characterization to build new chemically sensitive devices or to improve existing ones. The bottom line in the design and manufacture of modern gas sensors is the transfer from ceramic(of Figaro type) to thin film gas sensors(TFGs). This transfer provides new opportunities for further microminiaturization, power consumption and cost reduction of gas sensors. Therefore, at the present time, thin film gas sensors are the basis for the design of the modern gas sensitive multi-parameter microsensor systems. Applications of these systems include environment, security, home systems, smart buildings, transportation, discrete manufacturing, process industries and so on. Microelectromechanical systems(MEMS) based integrated gas sensors present several advantages for these applications such as ease of array fabrication, small size, and unique thermal manipulation capabilities. MEMS based gas sensors; which are usually produced using a standard CMOS(Complimentary Metal Oxide Semiconductor) process, have the additional advantages of being readily realized by commercial foundries and amenable to the inclusion of on-chip electronics. In order to speed up the design and optimization of such integrated sensors, microheater designs for gas sensor applications have been presented as first part of the present thesis. As heater design is the key part for a gas sensor operation. So 3D simulations have been used to optimize micro-heater geometry. The application of MEMS Design Tool(COVENTORWARE) has been presented to the design and analysis of micro-hotplate (MHP) structures. Coupled Electro-thermal analysis provided an estimation of thermal losses and temperature distribution on the hotplate for realistic geometrical and material parameters pertinent to fabrication technology. Five microheater designs have been proposed in terms of different sizes and shapes in order to optimize the microhotplate structure to be used for gas sensor operation for the specified range of temperature and power consumption. To produce a gas sensor, which is able to detect LPG leak, thin films of tin oxide have been developed. FR sputtering has been used to deposit gas sensitive tin oxide thin filmls under various deposition conditions. Four different values of pressure in the range from high pressure(5 X 10-2 mbar) to lower pressure (2 X 10-3 mbar), three RF power values 50, 75, 100 W and varied oxygen percentage in sputtering atmosphere (0-18%) have been used to optimize the material properties of tin oxide thin films to study the sensitivity towards LPG. All the samples have been analyzed using various macro and microscopic characterization techniques. Extensive studies have been done on the sensor response for the samples deposited under different conditions. Finally the sample film deposited at 5 x 10-3 mbar, with applied power of 75 W in the presence of 8% oxygen, showed maximum sensitivity towards LPG.

Стилі APA, Harvard, Vancouver, ISO та ін.

43

Chen, You-Ruei, and 陳宥瑞. "Gas water heater Efficiency Improvement and Design." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/08003735722868003472.

Повний текст джерела

Анотація:

碩士
朝陽科技大學
精密機械暨水下機電技術整合產業碩士專班
104
Abstract In today's gas water heaters have become general household essential goods. Gas water heater as the name implies, is a combustible gas and air are mixed in the way, after entering the burner gas mixing in the combustion chamber for combustion heaters, heat conversion achieved. In the case of today's emphasis on economic, security and environmental protection, in order to achieve better performance, lower cost, safety and reduce pollution, the development trend of today. This study will focus on a particular core heating gas water heater, burner and combustion chamber design incomplete combustion caused by poor design improvement process will be assisted by scientific simulation software to explore and improve gas water heater caused by bad design incomplete combustion problems. Keywords: Gas water heaters, Gas mixed with air, Fluid mechanics

Стилі APA, Harvard, Vancouver, ISO та ін.

44

Costa, Victor Hugo Rocha. "Gas Water Heater Fan Power Dirver Implementation." Master's thesis, 2015. https://repositorio-aberto.up.pt/handle/10216/80657.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

45

Costa, Victor Hugo Rocha. "Gas Water Heater Fan Power Dirver Implementation." Dissertação, 2015. https://repositorio-aberto.up.pt/handle/10216/80657.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

46

Silva, Michael Neiva da. "Thermoelectric Energy Generator Heat Recovery System for Gas Water Heater." Master's thesis, 2014. https://repositorio-aberto.up.pt/handle/10216/89079.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

47

Silva, Michael Neiva da. "Thermoelectric Energy Generator Heat Recovery System for Gas Water Heater." Dissertação, 2014. https://repositorio-aberto.up.pt/handle/10216/89079.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

48

Lin, Wei Jing, and 林暐淨. "Numerical Simulation of Gas Water Heater Incomplete Combustion due toBalcony Clothes." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/5u9hc2.

Повний текст джерела

Анотація:

碩士
國立聯合大學
環境與安全衛生工程學系碩士班
106
Every year when the winter cold current strikes, the use or improper setting of the gas water heaters causes frequent carbon monoxide poisoning incidents throughout Taiwan. However, the main reason for the frequent occurrence of carbon monoxide poisoning incidents is that, in addition to the doors and windows are closed, which makes the poor ventilation of the balcony, and the thick clothes on the balcony is another factor that causes the gas water heater to burn incompletely. Based on the general interior design of Taiwan's residential buildings, this study establishes the physical model of the clothes drying balcony and the interior, and uses the FDS fire simulation software to express the degree of clothing density on the wall opening of the daughter, and explores the proportion of the opening to the entire wall. The parameters of the speed inlet adjust the wind speed, the opening and closing of the balcony door, and the height of the water heater of the model, and analyze the diffusion path and concentration change of carbon monoxide. The results show that: (1) changing the opening degree when the speed inlet is zero does not have much influence on the carbon monoxide diffusion. The power of carbon monoxide diffusion is its own diffusion ability, and the closing of the balcony door can effectively prevent carbon monoxide. The accumulation of indoor space, while the balcony space is in a high concentration state. (2) The gas diffusion at a height of 1.5 meters at the water heater will be more uniform than that of the water heater at a height of 2 meters; increasing the opening at a wind speed will accelerate the diffusion of carbon monoxide concentration in the indoor space. After the wind speed reaches a certain level, Excessive opening will cause carbon monoxide to reach steady state more quickly; (3) It can be found from the figure that in the case of wind speed, increasing the opening to the side is more effective than increasing the opening height of the lower breathing zone.

Стилі APA, Harvard, Vancouver, ISO та ін.

49

Melo, Samuel Ferreira. "Gas Water Heater Electronic Control Unit with Integrated Electro-chemical CO Sensor." Master's thesis, 2015. https://repositorio-aberto.up.pt/handle/10216/88018.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

50

Melo, Samuel Ferreira. "Gas Water Heater Electronic Control Unit with Integrated Electro-chemical CO Sensor." Dissertação, 2015. https://repositorio-aberto.up.pt/handle/10216/88018.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

Дисертації з теми "Gas heaters"

Оформте джерело за APA, MLA, Chicago, Harvard та іншими стилями