The growing cost of energy combined with the increasing energy demand has driven the need for more efficient energy use. Air-to-air energy recovery in buildings has been shown to provide substantial energy savings in many cases. A new type of air-to-air energy recovery system, known as a run-around energy exchanger (RAEE), and which has excellent potential for the retrofit market, has been proposed and numerically modelled for heat and moisture exchange by Fan et al. (2006). This thesis focuses on the material properties of semi-permeable membranes required for each RAEE exchanger core.<p>Two commercially available membranes are considered in this thesis: a spunbonded polyolefin manufactured by DuPont with the trade name Tyvek®, and a two layer polypropylene laminate material manufactured by the 3M Company with the trade name Propore.<p>The moisture transfer effectiveness of the RAEE system depends mostly on the ability of its membrane to transfer water vapour. This effectiveness is investigated by measuring the vapour diffusion resistance of Tyvek® and Propore using a dynamic moisture permeation cell (DMPC). For Tyvek®, the average vapour diffusion resistance is 440 s/m, which corresponds to an expected typical RAEE energy recovery effectiveness of 52%. For Propore, the average vapour diffusion resistance is 140 s/m, which corresponds to an RAEE effectiveness of 62% in the same exchanger system.<p>The air permeability is also measured using the DMPC with Tyvek® having a Darcy air flow resistance of 27 nm-1 and Propore having a Darcy air flow resistance of 111 nm-1. The lower air flow resistance of Tyvek® is undesirable since air transfer is undesirable in the RAEE system. <p>The liquid penetration pressure is determined using a modified standard method that resembles the geometry of a membrane in the RAEE exchanger. It is found that the Propore has a liquid penetration pressure beyond the measurement capabilities of the apparatus (276 kPa); while the Tyvek® membrane has a liquid penetration pressure of 18 kPa which agrees well with published values. <p>The elastic moduli of the membranes are required to predict the membrane deflection under typical operating pressures and to properly size a support screen. The elastic modulus is determined using two tensile standards and a bulge test. The bulge test results are used in the design since the geometry of the bulge test better represents the situation of a pressurized membrane in the RAEE. The elastic modulus of Propore is found to be 20 ± 3 MPa and the elastic modulus of Tyvek® is found to be 300 ± 45 MPa. The values are used in subsequent calculations for sizing the square screen, where it is found that a screen with square openings of 12.7 mm (0.5 in.) is required to support the membrane. <p>The degradation of Tyvek® and Propore with UVC exposure is also investigated. It is found that both materials deteriorate when exposed to UVC radiation, and that the degradation is primarily a function of the exposure time and not the exposure intensity. <p>Considering all material properties tested, it is concluded that the Propore membrane is a better membrane choice for the RAEE than the Tyvek® membrane.

The growing cost of energy combined with the increasing energy demand has driven the need for more efficient energy use. Air-to-air energy recovery in buildings has been shown to provide substantial energy savings in many cases. A new type of air-to-air energy recovery system, known as a run-around energy exchanger (RAEE), and which has excellent potential for the retrofit market, has been proposed and numerically modelled for heat and moisture exchange by Fan et al. (2006). This thesis focuses on the material properties of semi-permeable membranes required for each RAEE exchanger core.<p>Two commercially available membranes are considered in this thesis: a spunbonded polyolefin manufactured by DuPont with the trade name Tyvek®, and a two layer polypropylene laminate material manufactured by the 3M Company with the trade name Propore.<p>The moisture transfer effectiveness of the RAEE system depends mostly on the ability of its membrane to transfer water vapour. This effectiveness is investigated by measuring the vapour diffusion resistance of Tyvek® and Propore using a dynamic moisture permeation cell (DMPC). For Tyvek®, the average vapour diffusion resistance is 440 s/m, which corresponds to an expected typical RAEE energy recovery effectiveness of 52%. For Propore, the average vapour diffusion resistance is 140 s/m, which corresponds to an RAEE effectiveness of 62% in the same exchanger system.<p>The air permeability is also measured using the DMPC with Tyvek® having a Darcy air flow resistance of 27 nm-1 and Propore having a Darcy air flow resistance of 111 nm-1. The lower air flow resistance of Tyvek® is undesirable since air transfer is undesirable in the RAEE system. <p>The liquid penetration pressure is determined using a modified standard method that resembles the geometry of a membrane in the RAEE exchanger. It is found that the Propore has a liquid penetration pressure beyond the measurement capabilities of the apparatus (276 kPa); while the Tyvek® membrane has a liquid penetration pressure of 18 kPa which agrees well with published values. <p>The elastic moduli of the membranes are required to predict the membrane deflection under typical operating pressures and to properly size a support screen. The elastic modulus is determined using two tensile standards and a bulge test. The bulge test results are used in the design since the geometry of the bulge test better represents the situation of a pressurized membrane in the RAEE. The elastic modulus of Propore is found to be 20 ± 3 MPa and the elastic modulus of Tyvek® is found to be 300 ± 45 MPa. The values are used in subsequent calculations for sizing the square screen, where it is found that a screen with square openings of 12.7 mm (0.5 in.) is required to support the membrane. <p>The degradation of Tyvek® and Propore with UVC exposure is also investigated. It is found that both materials deteriorate when exposed to UVC radiation, and that the degradation is primarily a function of the exposure time and not the exposure intensity. <p>Considering all material properties tested, it is concluded that the Propore membrane is a better membrane choice for the RAEE than the Tyvek® membrane.

京都大学 / 新制・課程博士 / 博士(農学) / 甲第23240号 / 農博第2447号 / 新制||農||1083(附属図書館) / 学位論文||R3||N5330(農学部図書室) / 京都大学大学院農学研究科地域環境科学専攻 / (主査)教授 北山 兼弘, 准教授 小野田 雄介, 教授 小杉 緑子 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DGAM

Corrosion is a major challenge in the use of molten fluoride salt as a coolant in molten salt reactors (MSRs). A promising way of satisfying the two requirements of high strength and corrosion resistance is to clad structural alloys with a corrosion resistant material. Four candidate cladding and structural alloy combinations—stainless steel 316L and Incoloy 800H structural alloys either diffusion bonded to Hastelloy N or electroplated with nickel—were thermally aged at 700 °C for two to eight months. Based on measured concentration profles, the diffusion resistance of the four material combinations was compared and diffusion results were extrapolated to an end of reactor lifetime. The most important conclusion from this work is that Hastelloy N is highly likely to be signifcantly more diffusion resistant than nickel. The difference in diffusion resistance between Incoloy 800H and stainless steel 316L is relatively small. Two methods were used for extrapolating experimental diffusion results: (1) a diffusion model and calculated diffusion coeffcients and (2) simulations with Thermo-Calc DICTRA. Some simulations were carried out with a corrosion boundary condition of near-zero chromium concentration, demonstrating the potential of simulations for predicting diffusionlimited corrosion in molten fluoride salts. A surprising result of these simulations is that decreasing the thickness of Ni plating did not increase the thickness of diffusion zones in underlying structural alloys. / Thesis / Master of Applied Science (MASc)

ABSTRACT KINETIC STUDIES FOR THE PRODUCTION OF TERTIARY ETHERS USED AS GASOLINE ADDITIVES Boz, Nezahat Ph. D., Department of Chemical Engineering Supervisor: Prof. Dr. Timur Dogu Co-supervisor: Prof. Dr. G&uuml / lSen Dogu June 2004, 174 pages In the present study, the kinetics studies for etherification reactions were investigated in detail. In the first phase of present study, different acidic resin catalysts were prepared by the heat treatment of Amberlyst-15 catalysts at 220&deg / C at different durations of time and also by the synthesis of sulfonated styrene divinylbenzene cross-linked resins at different conditions. A linear dependence of reaction rate on hydrogen ion-exchange capacity was in 2M2B+ethanol reaction. However, in the case of 2M1B+ethanol reaction hydrogen ion-exchange capacities over 2.8 meq.H+/g did not cause further increase in reaction rate, which was concluded to be majorly due to significance of diffusional resistances. DRIFTS experiments carried out with alcohols, isobutylene, isoamylenes and TAME (tert-amyl-methyl-ether) in a temperature range of 333-353 K supported a Langmuir-Hinshelwood type reaction mechanism involving adsorbed isoolefins molecules forming a bridged structure between &ndash / SO3H sites of the catalyst and adsorbed alcohol molecules. A rate expression derived basing on the mechanism proposed from the DRIFTS results gave good agreement with the published data. Reaction rate was found to give a sharp maximum at ethanol activity of around 0.1. The third phase of this work included evaluation of effective diffusivities and adsorption equilibrium constants of methanol, ethanol and 2M2B, in Amberlyst-15 from moment analysis of batch adsorber dynamic results. Models proposed for monodisperse and bidisperse pore structures were used for the evaluation of effective diffusivities. It was shown that surface diffusion contribution was quite significant. In the last phase of the work, a batch Reflux-Recycle-Reactor (RRR) was proposed, modeled and constructed to achieve high yields and selectivities in equilibrium limited reactions. The batch reflux recycle reactor was modeled by assuming plug flow in the reactor section, perfect mixing in the reboiler and vapor-liquid equilibria between the liquid in the reboiler and reactor inlet stream. In this system conversion values of isoamylenes reaching to 0.91 were achieved at 82&deg / C with almost 100% selectivity. Such conversion values were shown to be much higher than the corresponding equilibrium values that could be obtained in vapor phase fixed bed reactors. The activation energies evaluated in this system were found to be much less than the activation energies evaluated in the fixed bed reactor studies. This was concluded to be majorly due to the significance of transport resistant in the batch Reflux-Recycle-Reactor in which catalyst particles are partially wet. As a result of catalyst development, characterization, kinetic and reactor development studies carried out in this study, it was concluded that tert-amyl-ethyl-ether (TAEE) could be effectively produced and used as a gasoline blending oxygenate.

HotHumiBox är en försöksutrustning som finns på Linnéuniversitetet och som ska ge bättre kunskap och förståelse om hur fukt och temperatur varierar i en provkropp monterad mellan två kammare där klimatet kan styras var för sig. Syftet med examensarbetet är att undersöka om HotHumiBoxen fungerar väl och huruvida den kan börja användas i undervisningen i olika kurser inom institutionen för byggteknik på Linnéuniversitetet, bl.a. i samband med demonstrationslaborationer vid föreläsningar om fukt. För att genomföra arbetet har mätningar med tre olika klimat utförts på ett provelement som motsvarar en yttervägg som kan finnas i nybyggda typhus. Resultatet av mätningar utförda med HotHumiBoxen presenteras i form av tabeller och diagram och jämförs slutligen med beräkningar av fukt- och temperaturtillstånd. Jämförelsen mellan mätningar och beräkningar visar att givarna som styr klimatet i båda kamrarna visar mycket bra resultat. Däremot visar majoriteten av givarna i provelementet antingen lite för höga eller för låga värden för att resultatet ska anses som tillfredställande. För att få en bekräftelse på att HotHumiBoxen fungerar väl rekommenderas därför att ytterligare mätningar görs. / HotHumiBox is an experimental equipment that is available at Linnaeus University and is supposed to provide better knowledge and understanding about the way moisture and temperature varies in a building element installed between two chambers in which the climate can be controlled separately. The purpose of this work is to investigate whether the HotHumiBox works well and whether it can be used at various courses at the Department of Building Technology at Linnaeus University, such as demonstration laboratory experiments at lectures on moisture. Measurements with three different climates were performed on a building element that corresponds to a wall that could be installed in modern houses. The results of the HotHumiBox measurements are being presented in tables and diagrams and are being compared with moisture and temperature calculations. The comparison between measurements and calculations shows that the sensors which control the climate in both chambers show very good results. On the other hand, the majority of the sensors in the test element show either too high or too low values for the result to be considered as satisfactory. Therefore, it is recommended that some more tests and measurements are done before it can be concluded that the HotHumiBox work well.

This diploma thesis deals with suggestion of self-supporting insulating system that can be used for objects which insulating is more or less complicated. In this thesis are theoretically processed information about insulation systems while focus is on their structure, composition and principle of operation. Further, there is theoretically designed self-supporting insulating system which is practically built after theoretically composed testing for finding its basic properties. The most appropriate process of realization is formulated at the end after evaluation of the individual tests.