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$^{-2}$ at a fluid temperature difference of 175 $^\circ$C and a flow rate per fluid channel of 5 L min$^{-1}$. 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 Ciência e Tecnologia (FCT) and co-funded by FEDER through Operational Competitiveness and Internationalization Programme (POCI)

Evaluation of Effectivity of Renovation the Appartment Buildings

Käesoleva magistritöö pealkirjaks on „Kortermajade renoveerimise efektiivsuse hinnang“. Töö käigus analüüsiti kümmet erinevat viiekorruselist korterelamut, mis asuvad Tallinnas Mustamäel. Analüüsiti nende elamute energiaauditeid ning energiakulu andmeid, et teada saada, kas renoveerimise käigus energia tarbimine vähenes ning kui vähenes, siis millisel määral. Energia vähenes kõikidel korterelamutel. Analüüsi käigus selgus, et kõikides korterelamutes toimus pärast renoveerimist energia langus. Keskmine energiasääst 10 maja puhul oli 139,3 MWh. Kuna energia tootmine saastab õhku ning energia hind järjest tõuseb, siis renoveerimine tasub end igati ära. Mida rohkem renoveerimisse investeerida, seda suurem energiasääst on võimalik saavutada. Võrreldes valitud korterelamuid selgus, et kõige suuremaks energiasäästuks suudeti pärast renoveerimistöid saada 0,06 MWh m2 kohta, kuid kõige väiksemaks energiasäästuks jäi 0,02 MWh m 2 kohta. Antud säästudeni jõuti erinevalt -teostades erinevaid renoveerimistöid ning väga erinevate hindadega. Keskmiseks energiasäästuks ühe m2 kohta kõigi 10 maja puhul tuli 0,04 MWh. Kõik võrreldavad korterelamud olid saanud renoveerimistoetust KredExilt. On väga oluline, et seda on võimalik saada ka edaspidi. Rekonstrueerimistoetust rahastatakse perioodil 2015-2020 Euroopa Liidu Ühtekuuluvusfondist edasi ning seetõttu on võimalik veel palju korterelamuid soojustada ning seeläbi CO2 õhku paiskamist vähendada. Töö käigus käsitleti ka seda, kui palju oleks võimalik elamute renoveerimisega vähendada õhusaastet. 2013. aasta lõpuks oli toetuse abiga rekonstrueeritud 477 ning kõigi nende majade keskmine arvutuslik energiasääst on ligi 43%. Hinnanguliselt tähendaks see sellise hulga elamute ja säästu puhul ligi 60 GWh aastas kokkuhoitud kütteenergiat, mis tähendab, et umbes 12 500 tonni CO2 jääb õhku paiskamata. Võrreldava 10 korterelamu keskmiseks energiasäästuks oli ligikaudu 25 %. Töö käigus toodi välja, millised on korterelamute soojustamise lisavõimalused lisaks renoveerimisele. Lisasoojustamise variantidena on välja toodud varjupuude ning päikesepaneelide kasutamine.The heading of the current Master´s Thesis is “Evaluation of Effectivity of Renovation the Appartment Buildings.” Ten different 5-stories appartment buildings, which situate in Mustamäe 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, ‘SustainableDesign Engineering’, at Aalborg University in Denmark. We discuss how levels 2and 3 could be addressed in the future

Teaching physical education in the secondary school

xv,237 p; 21 cm