105 research outputs found
A thermoelectric power generating heat exchanger: Part I - Experimental realization
An experimental realization of a heat exchanger with commercial
thermoelectric generators (TEGs) is presented. The power producing capabilities
as a function of flow rate and temperature span are characterized for two
different commercial heat transfer fluids and for three different thermal
interface materials. The device is shown to produce 2 W per TEG or 0.22 W
cm at a fluid temperature difference of 175 C and a flow rate
per fluid channel of 5 L min. One experimentally realized design
produced 200 W in total from 100 TEGs. For the design considered here, the
power production is shown to depend more critically on the fluid temperature
span than on the fluid flow rate. Finally, the temperature span across the TEG
is shown to be 55% to 75% of the temperature span between the hot and cold
fluids.Comment: 9 pages, 11 figure
Seismic behaviour of precast sandwich wall panels of steel fibre reinforced concrete layers and fibre reinforced polymer connectors
In recent past, the authors developed an innovative modular system for low rise building made by structural sandwich panels. This system was conceived with the focus on the rationalization of the construction process and on the thermal efficiency of the building. Thus, the precast panels comprise two outer Steel Fibre Reinforced Self-Compacting Concrete (SFRSCC) layers, a thermal insulation material and Glass Fibre Reinforced Polymer (GFRP) connectors. Studies previously made by the authors have proved the viability of the proposed solution when subjected to flexural loads (out-of-plane loads). However, the in-plane biaxial cyclic behaviour of these type of panels has not yet been assessed. Therefore, to investigate the response of these panels to loading conditions that can occur in a seismic event, an experimental program was carried out. This program was composed of almost real-scale panels (2.0 m by 2.0 m), with and without openings, which were subjected to a constant vertical load representative of the load transferred by the slab to the panel, while horizontal reversed cyclic loading was imposed to the top of the panel. The in-plane cyclic behaviour of the panels was evaluated in terms of strength, stiffness, ductility and energy dissipation. The results have shown that the tested prototypes were able to withstand high values of lateral loads, namely 212 kN and 155 kN in the prototypes without and with opening, respectively.The first author acknowledges the financial support provided by FAPDF. The second author acknowledges the
financial support provided through the project ICoSyTec (POCI-01-0145-FEDER-027990) financed by Fundação para a CiĂȘncia e Tecnologia (FCT) and co-funded by FEDER through Operational Competitiveness and Internationalization Programme (POCI)
Evaluation of Effectivity of Renovation the Appartment Buildings
KĂ€esoleva magistritöö pealkirjaks on âKortermajade renoveerimise efektiivsuse hinnangâ. Töö
kĂ€igus analĂŒĂŒsiti kĂŒmmet erinevat viiekorruselist korterelamut, mis asuvad Tallinnas MustamĂ€el.
AnalĂŒĂŒsiti nende elamute energiaauditeid ning energiakulu andmeid, et teada saada, kas
renoveerimise kÀigus energia tarbimine vÀhenes ning kui vÀhenes, siis millisel mÀÀral. Energia
vÀhenes kÔikidel korterelamutel.
AnalĂŒĂŒsi kĂ€igus selgus, et kĂ”ikides korterelamutes toimus pĂ€rast renoveerimist energia langus.
Keskmine energiasÀÀst 10 maja puhul oli 139,3 MWh. Kuna energia tootmine saastab Ôhku ning
energia hind jÀrjest tÔuseb, siis renoveerimine tasub end igati Àra. Mida rohkem renoveerimisse
investeerida, seda suurem energiasÀÀst on vÔimalik saavutada.
VÔrreldes valitud korterelamuid selgus, et kÔige suuremaks energiasÀÀstuks suudeti pÀrast
renoveerimistöid saada 0,06 MWh m2 kohta, kuid kÔige vÀiksemaks energiasÀÀstuks jÀi 0,02 MWh
m
2 kohta. Antud sÀÀstudeni jÔuti erinevalt -teostades erinevaid renoveerimistöid ning vÀga erinevate
hindadega. Keskmiseks energiasÀÀstuks ĂŒhe m2 kohta kĂ”igi 10 maja puhul tuli 0,04 MWh.
KÔik vÔrreldavad korterelamud olid saanud renoveerimistoetust KredExilt. On vÀga oluline, et seda
on vÔimalik saada ka edaspidi. Rekonstrueerimistoetust rahastatakse perioodil 2015-2020 Euroopa
Liidu Ăhtekuuluvusfondist edasi ning seetĂ”ttu on vĂ”imalik veel palju korterelamuid soojustada ning
seelÀbi CO2 Ôhku paiskamist vÀhendada.
Töö kÀigus kÀsitleti ka seda, kui palju oleks vÔimalik elamute renoveerimisega vÀhendada
Ôhusaastet. 2013. aasta lÔpuks oli toetuse abiga rekonstrueeritud 477 ning kÔigi nende majade
keskmine arvutuslik energiasÀÀst on ligi 43%. Hinnanguliselt tÀhendaks see sellise hulga elamute ja
sÀÀstu puhul ligi 60 GWh aastas kokkuhoitud kĂŒtteenergiat, mis tĂ€hendab, et umbes 12 500 tonni
CO2 jÀÀb Ôhku paiskamata. VÔrreldava 10 korterelamu keskmiseks energiasÀÀstuks oli ligikaudu 25
%.
Töö kÀigus toodi vÀlja, millised on korterelamute soojustamise lisavÔimalused lisaks
renoveerimisele. Lisasoojustamise variantidena on vÀlja toodud varjupuude ning pÀikesepaneelide
kasutamine.The heading of the current MasterÂŽs Thesis is âEvaluation of Effectivity of Renovation the
Appartment Buildings.â Ten different 5-stories appartment buildings, which situate in MustamĂ€e
area in Tallinn, were analysed. Energy audits of these appartment buildings were analysed, also the
energy consumption data to find out whether the energy consumption decreased on the renovation
process and if yes, to what extent.
Preparing the master's thesis the author worked through the theme-related literature available and
the various analyses. In this work the energy audits of selected appartment buildings and energy
consumption data were used.
The current thesis gives an overview about the stages of renovations, and methods, also the main
places of heat loss, etc.
The thesys also explores the impact of the renovation to the environment, how much less does it
influence the environment.
The work outlines what are the opportunities for additional insulation of apartment buildings in
addition to the renovation. Additional possibilities could be using the shades of trees and the use of
solar panels
Towards a sustainable design-based engineering education
The engineering sciences were conceived at a different time, and for differentpriorities. One of the main problems with the engineering sciences is that designhas been excluded from their teaching curriculum; hence, they lack creativity andhave a narrow problem-solving focus with too much emphasis on mastering mathematical equations. Their standardization across the globe has failed to address the urgent need for designing for sustainability. In this research note, we outline whata Sustainable Design-Based Learning model/framework based on three levels ofambition, would entail: first, readjusting the engineering sciences to include designand sustainability as core elements; second, rethinking the engineering sciencesto support a program with sustainability as a core value; and third, rethinkingthe program with Sustainable Design as its prime objective. We illustrate levelof ambition one with the changes we have introduced in our program, âSustainableDesign Engineeringâ, at Aalborg University in Denmark. We discuss how levels 2and 3 could be addressed in the future
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