In the fall of 2019, a comprehensive idea study was conducted on heat storage in two rock caverns located at Näsudden in Skelleftehamn and was part of the project course "Energiteknik, huvudkurs" at Luleå University of Technology. This idea study investigated the conditions of using waste heat from Boliden AB:s copper smeltery (Rönnskär) and storing this waste heat in two rock caverns and use them as seasonal thermal storage tanks, with the purpose of using the heat in the nearby district heating network, thus replacing some of the oil burned at Rönnskär. To investigate this, the authors of the idea study looked at two different storage cycles of seasonal storage and modeled this in ANSYS Fluent to simulate the heat storage and the heat losses. The results from this idea study showed promising results for using these caverns as heat storage and this work is therefore a continuation of the idea study. Since the study provided a good understanding of the conditions for seasonal storage, some questions arose about how the rock caverns will behave during an intermittent operation, which is the planned mode of operating the caverns in case of deployment. In this thesis, intermittent operation of these caverns are explored and how this effects the temperature in the caverns and its surrondings, the charge/discharge speed, how insulated walls affect the operation and how much oil is replaced. At the beginning of this project a review of the idea study and similar projects was done to gain deeper knowledge about the subject, but also to get a wider grasp on the different problems that could arise during the thesis. Relevant data for the caverns was collected and acquired to get a deeper understanding of its geometry, layout and what kind of modifications are really possible. Further data from the district heating networks of Boliden AB and Skellefteå Kraft was acquired. The available waste heat from Rönnskär was examined and used to calculate the chargeable energy by hour for the caverns, with the limits of Skelleftehamn district heating network in mind. By examining the different steam boiler patterns, the discharge pattern could be calculated. Using CFD, the unknown global heat transfer coefficient between the cavern water and the cavern wall can be determined. This data was then used with a set of differential equations to model the behavior of the caverns in Simulink. This allowed to determine the behavior for the caverns during normal operation, such as how the heat losses evolve, how the temperatures fluctuate, how much heat the caverns can be charged with and how much they can discharge. The results from the simulations showed that the caverns discharge a higher amount of energy when operating intermittently than when operating seasonally. Depending on how the caverns are utilized, different amounts of discharged energy are obtained. This range from 2224,7MWh to 7846,1MWh for the different discharging patterns. The usage also affects the efficiency of the cavern giving the efficiency a range between 19% to 53,9%. The heat losses range from around 20kW to 1000kW, depending on operation. Insulating the cavern walls reduces on average the heat losses by a factor of 5. Operating the caverns intermittently would on average remove a total of 29 ktonne CO2 and 88,74 tonne NOx for its expected lifespan of 30 years. Economically, the rock caverns have good economic potential as they would save about 80 million SEK during their lifetime just from buying less oil. / Hösten 2019 genomfördes en omfattande idéstudie om värmelagring i två bergrum vid Näsudden i Skelleftehamn och var en del av projektkursen "\textit {Energiteknik, huvudkurs}" vid Luleå tekniska universitet. Denna idéstudie undersökte villkoren för att använda spillvärme från Boliden AB:s kopparsmältverk (Rönnskär) och lagra denna värme i bergrummen och använda dem som säsongslagrade ackumulatortankar. Syftet med detta var att använda värmen i det närliggande fjärrvärmenätverket och därmed ersätta en del av den förbrända oljan hos Rönnskär. Författarna utforskade detta genom att undersöka två olika lagringscykler för säsongslagring och modellerade detta i ANSYS Fluent för att simulera värmelagring och värmeförluster. Resultaten från idéstudien visade lovande resultat för säsongsbaserad värmelagring i dessa bergrum och detta arbete är därför en fortsättning av idéstudien. Eftersom studien gav en god förståelse för förhållandena för säsongslagring, uppstod några frågor om hur bergrummen kommer att bete sig under en intermittent drift, vilket är den planerade driften av bergrummen vid en framtida användning. I detta projekt undersöks intermittent drift av dessa bergrum och hur detta påverkar temperaturen i bergrummen och dess omgivning, laddnings- / urladdningshastigheten, hur isolerade väggar påverkar driften och hur oljeförbrukningen reduceras. I början av detta projekt gjordes en genomgång av idéstudien och liknande projekt för att få djupare kunskap om ämnet, men också för att få ett bredare grepp om de olika problem som kan uppstå under arbetets gång. Relevant data för bergrummen samlades in och anskaffades för att få en djupare förståelse för dess geometri, layout och vilken typ av ändringar som verkligen är möjliga. Ytterligare data från fjärrvärmenätverket för Boliden AB och Skellefteå Kraft förvärvades. Den tillgängliga spillvärme från Rönnskär undersöktes och användes för att beräkna den urladdningsbara energin per timme för bergrummen, med begränsningarna i Skelleftehamns fjärrvärmenät i åtanke. Genom att undersöka de olika ångpannmönstren kan urladdningsmönstret beräknas. Med hjälp av CFD kan den okända globala värmeöverföringskoefficienten mellan bergrumsvattnet och bergväggen bestämmas. Denna data användes sedan med en uppsättning differentialekvationer för att modellera driften av bergrummen i Simulink. Detta gjorde det möjligt att bestämma beteendet för bergrummen under normal drift, till exempel hur värmeförlusterna utvecklas, hur temperaturen fluktuerar, hur mycket värme bergrummen kan laddas med och hur mycket de kan ladda ur. Resultaten från simuleringarna visade att bergrummen kan ladda ur en större mängd energi än vid en säsongsbetonad drift. Beroende på hur grottorna utnyttjas erhålls olika mängder urladdad energi. Detta sträcker sig från 2224,7MWh till 7846,1MWh för de olika urladdningsmönstren. Användningen påverkar också grottans effektivitet vilket ger en effektivitet mellan 19% och 53,9%. Värmeförlusterna sträcker sig från cirka 1000 kW till 20kw, beroende på drift. Isolering av bergväggarna minskar i genomsnitt värmeförlusten med en faktor 5. Att använda grottorna intermittent skulle i genomsnitt ersätta totalt 29 kton CO2 och 88,74 ton NOx för den förväntade livslängden på 30 år. Bergrummen har även god ekonomisk potential eftersom de skulle spara cirka 80 miljoner SEK under sin livstid bara från minskade oljekostnader.

Master thesis deals with the utilization of waste heat from Nova Mosilana company. Theoretical part of this work is focused on the waste heat description (heat, heat quantity, heat temperature/quality, composition of waste stream) in which a considerable energy potential is hidden. The other parts describe waste heat technology, especially heat pumps, Organic Rankine Cycle (ORC) and system absorption cooling. Some of the technologies described in the theoretical part are used in the design of the more efficient existing waste heat utilization, especifically power and cold production.

This Master’s thesis focuses on the design of vertical heat recovery steam generators. This work focuses on three main objectives. The first objective is to describe the heat recovery steam generators, there basic principle and construction. The second focal objective is thermal calculation, design of heat tranfer surfaces and choice of materials. The third objective was to calculate the boiler loss, hydraulic calculation and subsequent design of the drum dimensions.

This thesis is focused on the design of steam boiler like a supplement for cogeneration unit of biogas plant. The main idea is to use a waste heat from the exhaust gasses to produce a technological steam of required parameters. The thesis contains of a calculation an amount of the heat in exhaust gasses and a heat exchange surface. An Aerodynamic loss and a wall thickness of the boilers are verified by strength calculation in the next parts of this thesis. At the end of this thesis are made projection drawings and diagram, which are made of the calculations.

This master’s thesis deals with the design of a heat recovery steam generator. The introductory part of the thesis is dedicated to waste heat boilers, their division and their utilization in combined cycles gas turbine. In the following chapter, an analysis of the existing combined heat and power plant operation is performed. In the next part of the thesis, the conceptual layout of the new source is designed. Subsequently, the thermal calculation of the boiler is carried out as well as the design of individual heat exchanging surfaces. The sixth chapter deals with the strength calculation of the boiler and the outer piping, chambers and drum are designed here. At the end of the thesis there are described off-design states of the new combined cycle gas turbine.

This thesis deals with the design of a Heat Recovery Steam Generator (HRSG). Theintroductory part is devoted to a brief description of the boiler, the specified parametersand the compilation of the temperature profile. The main computational part of thiswork is divided into 6 parts. The first contains preparatory calculations, including thecalculation of boiler eiciency. In the second part, a flue gas duct is designed. This isfollowed by a thermal calculation of the boiler for all heat exchange surfaces. The last 3parts deal with the design of the drum, piping and the loss of boiler draft calculation.

The aim of this work is to design data center placed into an ISO container used for transportation. Maximization of the space efficiency and minimization of the running costs are primary. This work also contains a measurement of data center electronic parts power consumption, a computational fluid dynamics model, a simulation of external thermal gains and a 3D model with basic technical drawings.

The aim of this diploma work is the study and the modeling of an Organic Rankine Cycle (ORC). Organic Rankine Cycle is used for heat recovery from low-potential heat sources. Their working fluid is a refrigerant or a hydrocarbon whose properties are adapted to the conditions in which the heat recovery is performed. The other chapters include the technical resolution of exhaust-heat exchanger of cogeneration unit for application ORC and partially economic study use in Czech Republic.

Main purpose of this thesis is to explain the issue of waste heat from broader point of view. It´s substantial part therefore deals with various available methods of waste heat utilization and their analysis. Large part of the thesis is devoted to description and usage of heat exchangers, heat pumps and thermal energy storage. The main theme of the thesis is the use of waste heat from industrial laundry room. It also introduces the process of the professional maintenance service along with its specifications and parameters of waste streams from washing machines. Main goal of the practical part of the thesis is to design equipment which could be used to store waste heat from washing machines. This equipment is designed to be used for specific process in NETME Centre laboratory. In conclusion, thesis addresses the propposed equipment from the energetical and economical point of view.

This diploma thesis deals with the design and optimization of the control valve for EHRS exchanger. The first part of the thesis contains a research describing the historical development of internal combustion engines, their impact on the environment and especially the possible ways of waste heat recovery. The second part focuses on the design of the control valve and experimental measurement to verify its functionality. The final part contains an analysis of pressure losses of the designed valve to improve its construction disadvantages.