<p>This thesis presents a study of the cooling process of a solid block performed by a turbulent air flow channel. The study focuses on the turbulent flow and its influence in the heat transfer of the block.</p><p>The first part of the thesis is an analysis of the different turbulent model and their adaptation on the necessities of this study. Once the turbulent model has been confirmed it makes a study of the behavior of the cooling process by CFD (Computational Fluid Dynamics), and an analysis of the numerical accuracy of this computational study.</p><p>When the procedure of the study of the cooling process is defined it proposes some different variations in the initial solution to improve this process. The study concentrates in variations of the turbulence and the geometry of the studied block.</p><p>Finally, the different improving are discussed analyzing parameters as the heat transfer, pressure drop, time consuming or energy consuming.</p>

<p>This project has been developed at the company Gavlegardarna. The companyowns a large part of the buildings of Gävle and two of them are the objective ofthe project. Gavlegardana is highly concerned about the environment; for thisreason, they cooperate on the subject with the energy management from theirtechnical department.</p><p>Gävle is one of the Swedish cities where the DH (district heating) network isdistributed, arriving to most of the dwellings, industries and commercialbuildings. As DH uses environmentally friendly sources of energy,Gavlegardana is introducing it in its buildings.</p><p>Electrical radiators and boilers were installed in the buildings when the price ofelectricity was more affordable than nowadays. The price of the electricity canbe considered 1,23 SEK/kWh while the DH price is 0,45 SEK/kWh.</p><p>Consequently, this is another reason why the objective of the company at thepresent time is to replace electrical space heating systems by means of districtheating.</p><p>The energy balance of the buildings is analysed in order to study their currentenergy situation. This entails the consideration of heat gains and lossesinvolved. The heat gains of the building are the heat from solar radiation whicharrives at the building trough the windows, the heat internally generated (bypersons, lighting and other devices) and the heat supplied. The heat losses are composed by the transmission trough walls and windows, the infiltrations, the heat used for hot tap water and the ventilation losses.</p><p>An important part of the work required to calculate the energy balance hasconsisted of the collection and organization of all the data (areas, types ofmaterial, electrical devices, lighting, number of employees, opening hours...).This data comes from the drawings of the buildings provided by the companyand from the information gathered during the visits to the installation. In addition, the ventilation flows were measured in-situ using the tools provided by Theorells.</p><p>Gavle Energi, the DH distributor company, has been contacted in order to fixthe cost and other details related to the district heating connection. The heatexchanger models, selected from Palmat System AB, are TP20 for Building Aand TP10 for Building B. TP20 provides 100 kW of heating and 0,4 l/s of hot tap water and TP10 provides 50 kW and 0,31 l/s respectively. The capital cost is 187500 SEK which includes the heat exchangers and the connection cost.</p><p>As the secondary circuit is not currently installed because the existing system iscomposed by electrical radiators, the installation of the piping network in thebuilding has been designed. The radiators’ power is calculated taking intoaccount the need of heat in each room which is estimated as the transmissionlosses. This need of heat calculated is higher than the energy currently supplied which means that the thermal comfort is not achieved in all the rooms of the buildings.</p><p>In spite of using more energy for space heating, the change of heat sourceentails a lower energy cost per year. The selected radiators are from Epeconand the investment cost (including the installation) is 203671 SEK. The brand of the selected pipes is Broson and the investment cost of the total piping system is 66000 SEK.</p><p>The initial investment of the new installation is 457171 SEK, considering the DHconnection, heat exchangers, radiators and pipes. If the initial investment istotally paid in cash by the company the payback will be fulfilled in 6 years. Incase of borrowing the money from the bank (considering an interest rate of 5%), two possibilities can be considered: paying back the money in annual rates over 15 years or 30 years of maturity. The paybacks are 11 and 8 years respectively.</p><p>After designing the DH piping system in the buildings, estimating the total costs of the investment and studying the project’s feasibility by suggesting different payment options, some possible energy savings are recommended.</p><p> </p><p>The first of the options refers to the transmission losses trough the windowswhose values’ are considerably high. Using a glass with a lower U-value, theselosses can decrease until 66% (with triple glass windows). Consequently, thepower required for space heating can also be reduced until 26%.</p><p>Regarding the ventilation, rotating heat exchangers are currently used, whichentails the problem of smells mixture detected by the users of the buildings. By changing them with flat-plate heat exchangers, the problem is solved and the efficiency is increased from 66% to 85%. The new heat exchanger cost is340387 SEK and it has a payback of 10 years.</p>

<p>Detta arbete beskriver hur Herons ångkula fungerar och hur den har byggts.</p><p>Ånkulan konstruerades för ca 2000 år av Heron.</p><p>Meningen var att få fram en verkningsgrad eftersom denna var okänd. Verkningsgraden blev aldrig konstaterad. Endast en teoretisk beräkning för verkningsgraden gjordes. Kulan sattes inte i rotation av ångtrycket som byggdes upp när det eldades under denna.</p><p>Anledningen var troligen att det var för mycket friktion i tätningen som skulle tillföra matarvatten in i kulan. Värmeöverföringen mellan gaslågan och kulkroppen var inte heller den mest optimala.</p><p>Kulan med tillhörande kringutrustning byggdes under dec-07/jan-08 efter eget tycke och utan någon existerande ritning. Den byggdes för att efterlikna originalet så mycket som möjligt. Dessutom hade en mindre ångkula byggts några år tidigare och denna hade visat sig fungera. Denna något större ångkula fick därför samma utseende.</p><p>Eftersom ångkulan inte orkade rotera råder det inga tvivel om hur ineffektiv denna tidiga reaktionsmotorn är.</p><p>Den fick ingen praktisk betydelse för 2000 år sedan, och det har den inte idag heller.</p><p>En framräknad verkningsgrad finns redovisad och denna blev mycket låg.</p><p>Det var stimulerandel att bygga Herons ångkula men konstruktionen i sig tillhör inte de mest lyckade.</p> / <p>This work describes how the Herons steam ball was built and how it works. It was constructed by Heron 2000 years ago. The purpose was to determine the efficiency of the steam ball because it was unknown. The efficiency was never determined. It was only theoretically determined by calculations. The steam pressure never gave the steam ball rotation when heat was added underneath the construction. A possible reason was that friction in the sealing for supplying feed water into the steam ball was too high.</p><p>The heat transfer was also a reason that the construction did not rotate.</p><p>The steam ball and necessary equipment was fabricated in dec-07/jan-08. It was built without any drawings. The goal was to make it look like the original as much as possible. A smaller steam ball was built some years before. This one did rotate and therefore was the same design given to the bigger one.</p><p>Because of the lack of rotation there was no doubt if the steam ball was a sucsess or not.</p><p>It was not used for any real purpose 2000 years ago and this has not changed.</p><p>A calculated figure of the efficiency was documented in this rapport, and it was very low.</p><p>It was amusing to design and build the steam ball but the construction was clearly no success.</p>

Agglomeration (the sticking together of particles) is often the major growth mechanism in granulation processes. The population balance equation (PBE) is a mathematical framework that is often applied to systems to describe how the particle size distribution changes as a function of time. Different kinetic terms are included in the PBE to describe the different particle growth mechanisms. In this work, a new kinetic model framework is proposed for the growth mechanism binary agglomeration. Binary agglomeration means that only two particles are involved in an agglomeration event. The generality of the new model framework is an advantage over the previous coalescence kernel framework. It is shown that an existing coalescence kernel model can be expressed by means of the new framework. The new model framework is then adapted to the special case of fluidized bed granulation (FBG) by proposing/choosing expressions for the three submodels in the model framework. An advantage of the new FBG model is that a maximum number of agglomeration events per unit time can be estimated. This means that the model is one step closer to being used predictively. At the moment, no population balance models can predict granulation processes where agglomeration is the dominant growth mechanism. It is shown that both the new FBG model and an existing model could fit experimental data well, however, the new model reflects the situation that the presence of surface liquid is rate limiting for the agglomeratio process. Experiments in a laboratory batch fluidized bed granulator were carried out. Samples of the particle size distribution were taken at intervals during an experiment. These data were used to fit the model parameters of the FBG model. The dissertation includes a discussion of the effect of certain operating conditions such as bed temperature and liquid spray rate on a model parameter.

This is a report written for an examination project C-level, on the subject of energy. The examination project is a product of the FVB Sweden AB (district heating bureau). It started with a meeting with Stefan Jonsson FVB Sweden AB, were he explained the content of the project, and from this a presentation of the problem was made. The problem that needed to be solved was how they could control the valves in the system to provide heating to everyone in the system. The valves are often oversized so the pump in the heating plant would have to be enormous to be able to provide enough flow to be sufficient, if everyone in the system had there valves fully opened.   I came up with two solutions to the problem, one was a wireless network that could keep track of the valves and the other solution was an extra sensor that was placed on the radiator. The purpose for that was to open the valve if the temperature dropped more than one degree inside. With the help of a program called IDA it was calculated that, if the temperature drop five degrees, they would have sixteen hours at the heating power plant to open the flow before the sensor open the valves.   After careful consideration I came up with the conclusion that the wireless network must be the best solution. Mostly because you can monitor all the clients in the system from the heating power plant and that will make it easier to discover faults and temperature differences. Wireless networks is already a well tested solution in form of wireless controlled electricity meters so it shouldn’t be to much of a problem connecting these sensors to it either.

This project has been developed at the company Gavlegardarna. The companyowns a large part of the buildings of Gävle and two of them are the objective ofthe project. Gavlegardana is highly concerned about the environment; for thisreason, they cooperate on the subject with the energy management from theirtechnical department. Gävle is one of the Swedish cities where the DH (district heating) network isdistributed, arriving to most of the dwellings, industries and commercialbuildings. As DH uses environmentally friendly sources of energy,Gavlegardana is introducing it in its buildings. Electrical radiators and boilers were installed in the buildings when the price ofelectricity was more affordable than nowadays. The price of the electricity canbe considered 1,23 SEK/kWh while the DH price is 0,45 SEK/kWh. Consequently, this is another reason why the objective of the company at thepresent time is to replace electrical space heating systems by means of districtheating. The energy balance of the buildings is analysed in order to study their currentenergy situation. This entails the consideration of heat gains and lossesinvolved. The heat gains of the building are the heat from solar radiation whicharrives at the building trough the windows, the heat internally generated (bypersons, lighting and other devices) and the heat supplied. The heat losses are composed by the transmission trough walls and windows, the infiltrations, the heat used for hot tap water and the ventilation losses. An important part of the work required to calculate the energy balance hasconsisted of the collection and organization of all the data (areas, types ofmaterial, electrical devices, lighting, number of employees, opening hours...).This data comes from the drawings of the buildings provided by the companyand from the information gathered during the visits to the installation. In addition, the ventilation flows were measured in-situ using the tools provided by Theorells. Gavle Energi, the DH distributor company, has been contacted in order to fixthe cost and other details related to the district heating connection. The heatexchanger models, selected from Palmat System AB, are TP20 for Building Aand TP10 for Building B. TP20 provides 100 kW of heating and 0,4 l/s of hot tap water and TP10 provides 50 kW and 0,31 l/s respectively. The capital cost is 187500 SEK which includes the heat exchangers and the connection cost. As the secondary circuit is not currently installed because the existing system iscomposed by electrical radiators, the installation of the piping network in thebuilding has been designed. The radiators’ power is calculated taking intoaccount the need of heat in each room which is estimated as the transmissionlosses. This need of heat calculated is higher than the energy currently supplied which means that the thermal comfort is not achieved in all the rooms of the buildings. In spite of using more energy for space heating, the change of heat sourceentails a lower energy cost per year. The selected radiators are from Epeconand the investment cost (including the installation) is 203671 SEK. The brand of the selected pipes is Broson and the investment cost of the total piping system is 66000 SEK. The initial investment of the new installation is 457171 SEK, considering the DHconnection, heat exchangers, radiators and pipes. If the initial investment istotally paid in cash by the company the payback will be fulfilled in 6 years. Incase of borrowing the money from the bank (considering an interest rate of 5%), two possibilities can be considered: paying back the money in annual rates over 15 years or 30 years of maturity. The paybacks are 11 and 8 years respectively. After designing the DH piping system in the buildings, estimating the total costs of the investment and studying the project’s feasibility by suggesting different payment options, some possible energy savings are recommended.   The first of the options refers to the transmission losses trough the windowswhose values’ are considerably high. Using a glass with a lower U-value, theselosses can decrease until 66% (with triple glass windows). Consequently, thepower required for space heating can also be reduced until 26%. Regarding the ventilation, rotating heat exchangers are currently used, whichentails the problem of smells mixture detected by the users of the buildings. By changing them with flat-plate heat exchangers, the problem is solved and the efficiency is increased from 66% to 85%. The new heat exchanger cost is340387 SEK and it has a payback of 10 years.

Fiberweb Sweden AB är en ledande tillverkare av polypropenbaserad fiberduk med Europa som huvudmarknad. När extrudering och spinning av polypropen till trådar utförs genereras beroende på polypropenets relativa känslighet för termisk nedbrytning lättflyktiga organiska föreningar vid smältning. Vid fiberspinning separeras den resulterande gasströmmen från produktflödet och behandlas innan det släpps ut i recipienten. Detta uppnås genom en för gasströmmen installerad kondensor. Det huvudsakliga syftet med examensarbetet är att undersöka möjligheten att minska företagets utsläpp av lättflyktiga organiska föreningar genom att studera den befintliga kondensorns ingående kylvattentemperatur och dess inverkan på kondensatmängd. Arbetet innefattar även framtagandet av förslag gällande kort- och långsiktiga lösningar avseende företagets utsläpp till luft. Av den anledningen har mycket av tyngdpunkten av arbetet lagts på förståelsen av grundproblematiken genom att undersöka mekanismen för hur rökgaserna bildas. Detta innefattar kunskapen i grunderna för de organiska radikalreaktioner som sker vid den termiska nedbrytningen av polypropen vid extrudering. Den praktiska delen av arbetet är uppdelat i fyra försök. Genom att bygga en kondensationsenhet och koppla ett delflöde från rökgasreningsprocessen är försök genomförda med två olika gasflödeshastigheter och kylvattenflöden. Utvunnet kondensat vägs som funktion av tid. Effektivitetsgraden beräknas som funktion av inkommande gasmassflöde. Resultaten indikerar att genom temperatursänkning från 21C kondensatmängden fördubblas och med potentialen att minska Fiberwebs utsläpp till luft med mellan 2 % till 15 % (per spinnbeam). Den teoretiska beräkningen som utfördes visar en potentiell minskning av utsläppen till luft mellan 25% till 42%. Effekten av uppehållstid undersöktes. Planerade och oplanerade produktionsstopp resulterade i otillräcklig upplösning av resultaten beträffande uppehållstid. Resultat tyder på att processens installerade värmeväxlare (WRT) är underdimensionerad.

Detta arbete beskriver hur Herons ångkula fungerar och hur den har byggts. Ånkulan konstruerades för ca 2000 år av Heron. Meningen var att få fram en verkningsgrad eftersom denna var okänd. Verkningsgraden blev aldrig konstaterad. Endast en teoretisk beräkning för verkningsgraden gjordes. Kulan sattes inte i rotation av ångtrycket som byggdes upp när det eldades under denna. Anledningen var troligen att det var för mycket friktion i tätningen som skulle tillföra matarvatten in i kulan. Värmeöverföringen mellan gaslågan och kulkroppen var inte heller den mest optimala. Kulan med tillhörande kringutrustning byggdes under dec-07/jan-08 efter eget tycke och utan någon existerande ritning. Den byggdes för att efterlikna originalet så mycket som möjligt. Dessutom hade en mindre ångkula byggts några år tidigare och denna hade visat sig fungera. Denna något större ångkula fick därför samma utseende. Eftersom ångkulan inte orkade rotera råder det inga tvivel om hur ineffektiv denna tidiga reaktionsmotorn är. Den fick ingen praktisk betydelse för 2000 år sedan, och det har den inte idag heller. En framräknad verkningsgrad finns redovisad och denna blev mycket låg. Det var stimulerandel att bygga Herons ångkula men konstruktionen i sig tillhör inte de mest lyckade. / This work describes how the Herons steam ball was built and how it works. It was constructed by Heron 2000 years ago. The purpose was to determine the efficiency of the steam ball because it was unknown. The efficiency was never determined. It was only theoretically determined by calculations. The steam pressure never gave the steam ball rotation when heat was added underneath the construction. A possible reason was that friction in the sealing for supplying feed water into the steam ball was too high. The heat transfer was also a reason that the construction did not rotate. The steam ball and necessary equipment was fabricated in dec-07/jan-08. It was built without any drawings. The goal was to make it look like the original as much as possible. A smaller steam ball was built some years before. This one did rotate and therefore was the same design given to the bigger one. Because of the lack of rotation there was no doubt if the steam ball was a sucsess or not. It was not used for any real purpose 2000 years ago and this has not changed. A calculated figure of the efficiency was documented in this rapport, and it was very low. It was amusing to design and build the steam ball but the construction was clearly no success.

This thesis presents a study of the cooling process of a solid block performed by a turbulent air flow channel. The study focuses on the turbulent flow and its influence in the heat transfer of the block. The first part of the thesis is an analysis of the different turbulent model and their adaptation on the necessities of this study. Once the turbulent model has been confirmed it makes a study of the behavior of the cooling process by CFD (Computational Fluid Dynamics), and an analysis of the numerical accuracy of this computational study. When the procedure of the study of the cooling process is defined it proposes some different variations in the initial solution to improve this process. The study concentrates in variations of the turbulence and the geometry of the studied block. Finally, the different improving are discussed analyzing parameters as the heat transfer, pressure drop, time consuming or energy consuming.

The objective is to produce a recommendation for Bonava's future constructions regarding heating systems and installation methods. The report consists of a comparison between radiator system and underfloor heating by looking at the installation costs and the thermal comfort. It consists of a quantitative survey with measuring instruments to find out variations in the indoor temperature. The content can be used as guidelines for construction planning for apartment buildings to see which system that is most suitable for the cause. Based on the result, it can be concluded that the radiator system is cheaper to install than an underfloor heating system. The radiator system provides a more even indoor temperature. Radiator systems can therefore be said to be better from the thermal comfort aspect. Our technical examination and calculations indicate that the radiator system is cheaper and better seen for thermal comfort. Our recommendation to Bonava is therefore to choose this system. We also found through the index that it was a smaller difference between installation costs for the systems the larger the apartment area was. In terms of price, the difference between the heating systems is small when you consider the life-span of the systems. Installation costs do not therefore have to be decisive, but other factors may need to be taken into account in the choice of system.