Master of Science / Department of Architectural Engineering and Construction Science / Charles L. Burton / Ground source heat pump systems have been around for nearly 50 years. The efficiencies that can be achieved today are difficult to match with any other type of heating and air conditioning system. With the familiarity of the system, installed costs have become very reasonable, and in some cases have been the same or less expensive than other comparable systems. Given all this, the question remains – why aren't more of these systems being proposed and installed? This report will investigate some of the reasons why and what can be done to remedy them. Major issues include professional education, availability of research and design material, industry or governmental incentives, and education in our K-12 schools and universities. Certainly all participants in the design process, from the designer to the owner, play a part in this dilemma. Recommendations will be made that address key hurdles this industry faces regarding making ground source heat pumps the system of choice.

Exploiting solar energy technology for both heating and cooling purposes has the potential of meeting an appreciable portion of the energy demand in buildings throughout the year. By developing an integrated, multi-purpose solar energy system, that can operate all twelve months of the year, a high utilisation factor can be achieved which translates to more economical systems. However, there are still some techno-economic barriers to the general commercialisation and market penetration of such technologies. These are associated with high system and installation costs, significant system complexity, and lack of knowledge of system implementation and expected performance. A sorption heat pump module that can be integrated directly into a solar thermal collector has thus been developed in order to tackle the aforementioned market barriers. This has been designed for the development of cost-effective pre-engineered solar energy system kits that can provide both heating and cooling. This thesis summarises the characterisation studies of the operation of individual sorption modules, sorption module integrated solar collectors and a full solar heating and cooling system employing sorption module integrated collectors. Key performance indicators for the individual sorption modules showed cooling delivery for 6 hours at an average power of 40 W and a temperature lift of 21°C. Upon integration of the sorption modules into a solar collector, measured solar radiation energy to cooling energy conversion efficiencies (solar cooling COP) were between 0.10 and 0.25 with average cooling powers between 90 and 200 W/m2 collector aperture area. Further investigations of the sorption module integrated collectors implementation in a full solar heating and cooling system yielded electrical cooling COP ranging from 1.7 to 12.6 with an average of 10.6 for the test period. Additionally, simulations were performed to determine system energy and cost saving potential for various system sizes over a full year of operation for a 140 m2 single-family dwelling located in Madrid, Spain. Simulations yielded an annual solar fraction of 42% and potential cost savings of €386 per annum for a solar heating and cooling installation employing 20m2 of sorption integrated collectors.

This report is a case study about geothermal energy system and its application forthe hospital in the city of Gävle. Today the hospital uses district heating and -coolingas their main energy source.There is a report about the hospital in the city of Umeå where geothermal energyhas been installed. Both hospitals have the same need when it comes to using heatand cooling all year round. The hospital in Umeå installed geothermal energy sothat they got a less vulnerable energy system. The emissions of CO2 were also lowereddue to this installation.This report aims to answer the following research question.How geothermal energy can be a option of choice for the hospital I the city ofGävle?The report presents a literature study on subject close to this research question. Focusfor the report is to find out if increased electricity consumption is better than usinglocal district heating- and cooling. The report from the geothermal installation inUmeå has on big difference and that is from which fuels the district heating is produced.In Gävle the energy comes from biomass which gives that the emission factoris almost zero.The calculations and modelling are performed in Excel and the results presented ingraphs.The results are positive both from an economical view and environmental perspective.If the total electricity price doesn’t increase more than 36% per year then geothermalenergy is more cost effective. Looking at the emissions of CO2 equivalentswith an emission factor of 90.4 kg per MWh electricity the COP-factor should notbe lower than 7.5. If that can be reached, then geothermal energy performs betterthan district heating- and cooling.

The electricity system is particularly susceptible to climate change due to the close interconnectedness between not only electricity production and consumption to climate, but also the interdependence of many European countries in terms of electricity imports and exports. This study provides a country based relative analysis of a number of selected European countries’ electricity system vulnerability to climate change. Taking into account a number of quantitative influencing factors, the vulnerability of each country is examined both for the current system and using some projected data. Ultimately the result of the analysis is a relative ranked vulnerability index based on a number of qualitative indicators. Overall, countries that either cannot currently meet their own electricity consumption demand with inland production (Luxembourg), or countries that experience and will experience the warmest national mean temperatures, and are expected to see increases in their summer electricity consumption are found to be the most vulnerable for example Greece and Italy. Countries such as the Czech Republic, France and Norway that consistently export surplus electricity and will experience decreases in winter electricity consumption peaks were found to be the least vulnerable to climate change. The inclusion of some qualitative factors however may subject their future vulnerability to increase. The findings of this study enable countries to identify the main factors that increase their electricity system vulnerability and proceed with adaptation measures that are the most eective in decreasing vulnerability.

The circular economy model has been proposed as a possible strategy for sustainable development in urban areas, implying that its core principles need to be cascaded down to various sectors, including the energy sector. District heating and cooling systems have great potential to enhance circularity on an urban level due to the establishment of synergies between different sectors, the incorporation of renewable energy sources and high efficiency. Indicator-based frameworks are valuable tools for monitoring the transition toward a circular economy. However, no framework to assess circularity in district heating and cooling systems was found. Thus, this study addresses this gap by reviewing currently available indicators used to assess district heating and cooling systems and understanding to what extent they reflect circular economy principles. For this purpose, 27 papers with 271 indicators were assessed against defined criteria related to the circular economy principles. These criteria included transparency, stakeholder engagement, effective communication, ability to track temporal changes, applicability, alignment with circular economy principles, validity and relevance to sustainable development. Afterwards, 89 indicators were selected and classified based on the 10R principle framework. The assessment revealed that the assessed papers cover a wide range of topics and assessment types and that none of the assessed papers fulfils all of the assessment criteria. Moreover, most of the identified indicators connect to the environmental and economic pillars of sustainable development, and the identified indicators focus primarily on the R principles of Reduce and Recover. This study laid the foundation for further research on the relationship between district heating and cooling systems and the circular economy by identifying the understudied areas and highlighting the need to develop tailored indicators to measure circularity in these systems.

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This thesis is concerned with a theoretical and experimental study of the hydrodynamics and heat transfer characteristics of viscous fluids flowing in tubes under laminar conditions. Particular attention has been given to the effects of the rheological properties and their variation with temperature. A review of problems of this type showed that in spite of the many potential applications of the results in a wide range of industries the subject had not been well developed and further work is justified in order to fill some of the gaps in our knowledge. The early part of the thesis considers the justification of the work in this way and sets down the scope and objectives. A computer progracune was then developed to allow the governing equations of the problem to be solved numerically to give the velocity and temperature profiles and pressure drop for both heating and cooling conditions. The results were also presented in the form of Nusselt numbers as a function of the Graetz numberp since this form is useful for engineering design purposes. The validity of the predictions were then checked by a programme of experimental work. Temperature and velocity profiles have been measured in order to provide a more severe test of the theory than could be imposed by the measurement of overall heat transfer rates. A combined thermocouple probe/Pitot tube was developed to allow simultaneous measurements of velocity and temperature to be made. A Newtonian oil and two non-Newtonian Carbopol solutions were studied. This is the first time that velocity and temperature profiles have been measured for non-Newtonian fluids in this type of situation. The results of the work heve shown that (a) the velocity and temperature profiles and pressure drops are greatly affected by the temperature dependence of the rheological properties and since real viscous fluids are normally very temperature-sensitive it is important that this effect is properly taken into account. (b) the engineering design correlations commonly used for the prediction of heat transfer coefficients can be seriously in error, especially for cooling conditions and when non-Nevitonian fluids are being considered. (c) a mathematical model can be developed which accurately describes all the phenomena and gives predictions which are very close to those observed experimentally. An important objective was to develop more accurate engineering design correlations for non-isothermal pressure drop and heat transfer rates.

O monitoramento de emulsões utilizadas na indústria metalmecânica compõe uma importante atividade para o controle da qualidade das peças trabalhadas, proporcionando também o aumento da vida útil de ferramentas e maquinários utilizados neste setor através da lubrificação e refrigeração da região de corte. Em grande parte dos casos, estas emulsões são preparadas pela diluição de um fluido de corte em meio aquoso, constituindo assim um conjunto de gotículas estabilizadas em um meio contínuo devido à presença de compostos emulsificantes, estando constantemente sujeitas a ciclos de aquecimento e resfriamento durante os processos de usinagem. Apesar do acompanhamento deste material ser realizado através de análises periódicas usuais, não há um método eficiente estabelecido para verificar sua qualidade em tempo real e em linha de processo. Neste contexto, torna-se possível aplicar técnicas relacionadas à espectroscopia UV-Vis para se obterem informações sobre a estabilidade destes sistemas, correlacionando intensidades de espalhamento de luz com as dimensões das gotas presentes no meio. Dessa forma, tornou-se possível o estudo da desestabilização térmica de emulsões de um fluido de corte comercial, a qual mostrou-se, através do acompanhamento do cálculo do expoente do comprimento de onda, dependente do tempo de exposição ao aquecimento e de sua temperatura média temporal, não sendo influenciada pela perda de meio contínuo por processos evaporativos ou sua posterior reposição. Também se verificou que parâmetros típicos do processo de preparo de emulsões, como a temperatura do meio dispersante e o tempo de repouso do fluido de corte sobre a superfície do mesmo, apresentam fundamental importância para a definição do tamanho médio de gota inicial destes sistemas, o que forneceu evidência da possibilidade de se relacionar a área sob espectros de extinção de luz com tamanhos médios de gota. / The monitoring of emulsions used in the metal-mechanical industry comprise an important activity to the quality control of the products manufectured, also providing an increase in the working life of the tools and machinery employed in this sector through the lubrication and refrigeration of the cutting zone. In the majority of cases, these emulsions are prepared diluting a metalworking fluid in an aqueous media, constituting a collection of particles stabilized by emulsifiers and undergoing heating and cooling cycles during metalworking processes. Currently, monitoring routines are based on regular analyses of samples taken from the process fluid, and an effective in-line method is not available to monitor emulsion quality in real time. In this context, it is possible to apply techniques related to UV-Vis spectrocopy in order to obtain information concerning the stability of those systems, correlating light scattering intensities to the droplet dimensions. In this study, it was possible to investigate the thermal destabilisation of a commercial metalworking fluid emulsion, which showed, through the evaluation of the wavelength exponent, to be dependant on the exposure time to heating and its time-averaged temperature. It was also noted that the loss of continuous phase by evaporation and its reposition do not affect the emulsion stability. Moreover, it was observed that important emulsion preparation parameters, such as continuous phase temperature and the time span between the addition of the metalworking fluid on the water surface and the stirring, have fundamental roles in defining the initial average droplet size, which made possible to correlate the area under the light extinction spectra with average droplet sizes.