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Tutkimuksen tavoitteena oli suunnitella ja rakentaa pientalo, jonka lämmitysenergiankulutus on korkeintaan puolet nykyisten tavanomaisten talojen kulutuksesta. Energiansäästön keinot olivat hyvin lämmöneristetty, tiivis ulkovaippa ja ilmanvaihdon tehokas lämmöntalteenotto. Koetalo rakennettiin 1991, ja rakennuksessa tehtiin seurantamittauksia kaksi vuotta marraskuusta 1991 alkaen. Saatujen tulosten perusteella rakennuksen lämmitysenergiankulutus oli noin 47 % tavanomaisten Espoossa sijaitsevien talojen kulutuksesta. Energiansäästön lisäinvestointien takaisinmaksuaika on 5 - 6 vuotta. Myös hyvin eristetyn puurunkoisen ulkovaipan toimivuus havaittiin moitteettomaksi. Paksu lämmöneristys ei ollut rakenteiden kosteusteknisen toimivuuden kannalta ongelmallinen. Rakennuksen huoneilman laatu todettiin mittausten perusteella hyväksi.

Abstract The purpose of this study is to define and assess a new, renewable and sustainable energy supply system for islands and remote area where ocean thermal energy conversion (OTEC)/photovoltaic with hydrogen storage system is proposed. Components of this system are a turbine, generator, evaporator, condenser, pumps, photovoltaic panels, electrolyzer, hydrogen tanks, fuel cell and converter. To evaluate the proposed hybrid system, energy, exergy and economic analysis are employed. For OTEC, an optimization algorithm is applied to find the optimum working fluid (R134A, R407C, R410A, R717, R404A, and R423A), evaporation and condensation temperatures, and cold and warm seawater temperature differences between the inlet and outlet of evaporator/condenser. The results demonstrate that the maximum specific power of OTEC was achieved to be 0.3622 kW/m2 for R717 and 0.3294 kW/m2 for R423A working fluids. The overall energy efficiency for the hybrid renewable energy system was obtained 3.318%. The maximum energy loss was occurred by the turbine. The exergy efficiency of the hybrid system was obtained 18.35% and the payback period of the proposed system was obtained around 8 years. The unit electricity cost for the system was achieved as 0.168 $/kWh which is valuable compared to 0.28 $/kWh of the previous system.

Abstract Green roofs have been used widely in tropical countries due to their energy-saving and passive cooling effect. However, the model to calculate a thermal performance evaluation metric has yet to be established, which has hindered the inclusion of green roof in the envelope thermal performance standards in building regulations. This paper aims to develop a model to predict Roof Thermal Transfer Value (RTTV) of green roofs under a tropical climate. Firstly, the efficiency and accuracy of hygrothermal transfer model of green roof was validated against field data, and annual heat gain through four types of green roofs was simulated. Subsequently, the RTTV of four green roofs was calculated based on linear interpolation between RTTV of a common bare roof and corresponding annual heat gain, which ranged from 2.29 to 2.49 W/m2. Given the complexity and time-consuming of RTTV calculation by the hygrothermal transfer model, three types of regression models were developed based on the dataset of four significant design factors and corresponding values of RTTV. And it was found that multilayer perceptron (MLP) regression method had a better performance than multiple regression (MR) and random forest (RF) method. Finally, the equivalent thermal resistance of plant layer was calculated based on the RTTV model and other five simplified calculation methods, and the implicit reason that differences exist among them were discussed. The conclusions drawn in this paper can provide a methodology for a quick evaluation of thermal performance of green roof during the early stages of design.

Tutkimuksessa tarkasteltiin suuren 20 000 m3:n öljyterässäiliön muuttamista lämpövarastoksi. Koerakentamiskohteena oleva öljysäiliö sijaitsee Vantaan Sähkölaitos Oy:n Martinlaakson voimalaitoksen pihassa. Öljysäiliön halkaisija on 34 m ja räystäskorkeus 22,1 m. Säiliön korkeus-halkaisijasuhde H/D on 0,65. H/D-suhteen pitäisi olla suositusten mukaan 1,5 - 1,8. Säiliön 100 mm:n eristys uusittiin vain katolla, jonne asennettiin 300 mm:n vuorivillaeristys. Säiliöön rakennettiin uudet putkilinjat, ja säiliön ylä- ja alavirtausputkeen asennettiin 7,5 m:n ympyräradiaalijakajat lämpimän veden kerrostumisen varmistamiseksi. Säiliö toimii normaalipaineessa alueella -15 mbar - +40 mbar ja maksimilämpötila on 95 oC. Lämpövaraston energiakapasiteetti on 890 MWh ladattuna ja lämpöteho mitoitusvesivirtauksella 500 kg/s on 80 MW. Lämpövarasto liitettiin suoralla kytkennällä kaukolämpöjärjestelmään. Muutostyön kustannukset olivat 7,5 milj.mk, joka on uuden vastaavan säiliön rakentamiskustannuksista n. 80 %. Kauppa- ja teollisuusministeriön koerakentamistukea hankkeelle saatiin 1,5 milj.mk (20 %). Säiliön toimivuutta seurattiin syksystä 1990 kevääseen 1992. Säiliötä ladattiin vuoden jaksolla keväästä 1991 kevääseen 1992 n. 21 GWh, mikä merkitsee n. 24 täyttä latauskertaa. Lämpöhäviöt tuona aikana olivat odotetusti suurehkot, n. 535 MWh eli n. 2,5 % ladatusta energiasta. Vantaan lämpövaraston höyrynkulutus oli 1 013 MWh ja pumppausenergia siitä noin puolet, 458 MWh. Suurehkot lämpöhäviöt ja runsas höyrynkulutus johtuivat säiliön eristyksestä ja pumppausenergian suurempi kulutus pumppujen mitoituksesta. Vantaan lämpövaraston tuotoksi arvioitiin n. 700 000 mk vuodessa. Investoinnin takaisinmaksuajaksi em. tuotolla tulee 5 %:n korolla n. 14,5 vuotta. Jos investoinnista vähennetään nykyisin saatava lvv:n vähennysvaikutus, lyhenee takaisinmaksuaika n. 11,5 vuoteen.

Abstract Multiple-effect evaporator (MEE) is used for concentrating the liquor. A substantial energy saving can be achieved by integrating MEE with a thermo-vapor compressor (TVC). TVC is a device in which the low-pressure vapor produced from MEE is compressed with the help of the high-pressure motive steam supplied externally, to produce a medium pressure vapor. This medium pressure vapor acts as a heat source for MEE. The high-pressure motive steam can be produced from concentrating solar thermal system, which is a renewable and non-polluting source of energy. The present study deals with the integration of linear Fresnel reflector (LFR) with MEE-TVC system. The objective of the present work is to minimize the total annual cost for the integrated MEE-TVC and LFR system. The important parameters affecting the annual cost for the integrated system are solar design radiation and temperature of the motive steam. A methodology is developed to determine the optimal solar radiation and steam temperature. The proposed methodology is demonstrated through a case study for manufacturing of corn glucose. The annual cost for the system is 87,106 $/y, with optimal steam temperature 250 °C and optimal design radiation 600 W/m 2 . Sensitivity analysis is also carried out for the selection of the optimal operating parameters. The cost of the auxiliary heating source plays a dominating factor on the economic feasibility of the integrated system.

Abstract This paper presents the development and performance evaluation of a novel ceiling ventilation system integrated with solar photovoltaic thermal (PVT) collectors and phase change materials (PCMs). The PVT collectors are used to generate electricity and provide low grade heating and cooling energy for buildings by using winter daytime solar radiation and summer night-time sky radiative cooling, respectively. The PCM is integrated into the building ceiling as a part of the ceiling insulation and at the same time, as a centralized thermal energy storage to temporally store low grade energy collected from the PVT collectors. The performance of the proposed system was numerically evaluated based on a Solar Decathlon house using TRNSYS. The results showed that, in winter conditions, the proposed PVT–PCM integrated ventilation system can significantly improve the indoor thermal comfort of passive buildings without using air-conditioning systems with a maximum air temperature rise of 23.1 °C from the PVT collectors. Compared with the system using PCM but without using PVT collectors, the coefficient of thermal comfort enhancement in the kitchen, dining room and living room of the case building studied using the proposed system improved from almost zero to 0.9823 while the coefficient of thermal comfort enhancement in the study room improved from 0.0060 to 0.9921. In summer conditions, the proposed system can also enhance indoor thermal comfort through night-time sky radiative cooling.

Pulsed laser polymerization experiments have been performed on the bulk polymerization of dimethyl itaconate over the temperature range 20–50 °C. The activation energy and frequency factor were calculated as 24.9 kJ/mol−1 and 2.15 × 105 L/mol−1s−1, respectively. The activation energy is comparable with the methacrylate series of monomers. The frequency factor is relatively small and reflects steric hindrance in the transition state caused by the bulky 1,1, disubstitution in the monomer (and consequently the radical). The Mark–Houwink–Kuhn–Sakurada constants were also determined for poly(dimethyl itaconate) in tetrahydrofuran, these are reported as 46 × 10−5 dL/g (K) and 0.51 (α). The influence of penultimate units (γ-substituents) on homopropagation reactions is discussed particularly for polymerizations leading to significant 1,3 interactions in the resultant polymer. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 2192–2200, 2000