This thesis examines a possible control strategy to minimize flow fluctuations in Uppsala?s district heating system. High variations in flow rate may lead to complications caused by hydraulic constraints in the district heating system. These complications, such as inadequate pressure and temperature levels, increase the risk of heat delivery failures. It is therefore important to avoid such situations both for the producer and for the customers.Typically, the forward temperature is controlled by using a rough correlation with respect to the outdoor temperature.

The European Water Framework Directive (WFD; 2000/60/EC) was incorporated into the Swedish legislation in 2004 through the ordinance Förordningen om förvaltningenav kvaliteten på vattenmiljön (SFS 2004:660). The objective is that all water bodies shall reach a good status by the year 2015. In Sweden the comprehensive plans of the municipalities can play a large role in reaching these goals. A comprehensive plan deals with the long term water and land use of the municipality, which can facilitate an early consideration of water management in the planning process of the municipality. In Sweden five river basin districts have been established in accordance with the Water Framework Directive.

This bachelors thesis was made forWallenius Water AB to develop a basisfor an Airpurifier prototype. Wallenius Water isone of the world's leading environmentaltechnology companies engaged inchemical-free water treatment based onUV-radiation. The thesis aim was toproduce a basis for a prototype that canbe used in three applications:Standalone, RAS systems and ventilationsystems. The work includes anintroductory description of the theorybehind AOP technology based on aliterature review on the subject. Asurvey of products currently on themarket and a product specification hasbeen used as the basis for thepreparation of a number of concepts inthis report.

A patient simulator for testing anaesthesia machines has been developed at Maquet Critical Care AB, to reduce costly and time-consuming experiments on animals. The device simulates human lungs regarding lung dynamics and volume, uptake of anaesthetic agents and the production of carbon dioxide, heat and moisture. Further demands on the simulator are durability and size; the device shall be compact enough to be moveable.The resulting simulator fulfils the requirements and enables better repeatability and ability to test extreme cases than experiments on animals do.Uptake of the anaesthetic agent is achieved in a active carbon filter and controlled by regulating the flow. The flow is created by a regenerative blower and controlled using a proportional valve. The uptake can be set by the user or by a simple uptake model modified to recursively handle changes in the concentration of anaesthetic agent.Carbon dioxide is fed into the system from a tank by a mass flow regulator.

Given that the oil prices have risen and the environmental regulations has become more stringent, the interest in operating efficiency has increased. The project has investigated the possibility of producing electricity from waste heat generated in the diesel process. One technique to utilize and convert energy into electricity is the ORC (Organic Rankine Cycle). This process is based on the Rankine process (the steam process), the difference from the traditional Rankine process is that instead of water as a working medium, an organic substance is used. The main component used in the process is a evaporator, a turbine, a condenser and a pump.

Poly- and perfluoroalkyl substances (PFASs) are a group of environmental contaminants that have gained increasing attention due to their potential to bioaccumulate, environmental persistence and potential toxicity. PFASs have been found in surface water, sediment, air, soil, sludge and ice caps globally, as well as in wildlife and humans. Furthermore, PFASs have also been detected in drinking water, leading to raised concerns for human health, since drinking water is one of the most significant sources of PFASs for the general population. Conventional water treatment techniques have shown to be ineffective removing PFASs, highlighting the importance for further research to develop efficient removal techniques. The aim of this study was to investigate the removal efficiency of PFASs in water using two treatment techniques; granular activated carbon (GAC), type Filtrasorb 400®, and anion exchange (AE), type Purolite A-600. Additionally, the effect of dissolved organic carbon (DOC) on removal efficiency was studied.

This report will examine various solar energy technologies in order to decide if they could be applied in the Royal Seaport. The Royal Seaport is a Swedish urban district under development in Stockholm, with the goal of becoming a sustainable district. Two main techniques, solar collectors and solar cells, including sub-categories, are addressed in this report. Another sub-category, a hybrid system, will also be mentioned. The main difference between solar collectors and solar cells is the type of energy produced by the system.

Stage-discharge equations for lakes without disharge measurementsSimon AnderssonIn 2015 all lakes, rivers, coastal water and groundwater should be of good ecological statusaccording to the water framework directive from the European Union. In the process ofimproving the quality of Swedish water bodies, knowledge of where problems occur isneeded in order to utilize the resources optimally. The ability of lakes to store water is animportant factor since it controls the flow of water through the country. A stage-dischargeequation is a mathematical relation between discharge from a lake and its water level. Bybetter understanding of stage-discharge equations for lakes, their storage capacity can bedescribed better in hydrological models.This master thesis aims to evaluate methods for determining stage-discharge equations forlakes where a variable amount of field measurements is available.

This report investigates a possible solution to the problem with adapting wave powerplants to work in countries with tidal water. The wire connecting the buoy at the surface with the generator at the bottom needs to adjust to the varying water depth. Our solution to this problem is to attach the wire to a jack which is then placed inside the buoy. The jack is then powered by an electric engine. The report discuss what forces the buoy will be exposed to and then the structural integrity of the design is evaluated through simulations.

The task was to design and manufacture a submersible displacement pump working with the wobble plate principle. The main task for the Wobble plate pump is to be used as a sewage pump for smaller households or dewatering pump in environments where small flows and high pressures are acquired. For these purposes ITT Flygt sell a screw pump, PC-Grinder 3068. The hydraulic part of the PC-Grinder is manufactured by a subcontractor. Therefore ITT Flygt wants to evaluate an alternative to their screwpump PC-Grinder, which can be entirely manufactured by them self.

Hemp has been used for textiles for a long time in history until it became illegal to grow in many countries in the 1930s. It is interesting from an environmental point of view because it doesn?t need any pesticides and in most locations it doesn?t need any irrigation either, compared to cotton, which normally requires big amounts of both pesticides and water for irrigation. Hemp is a bast fiber, which means that the fibers are located on the bast of the stem (on the outer layer of the stem). Therefore they cannot be spun directly, they have to be removed from the stem first.

This degree project has been carried out in cooperation with Enertech AB in Ljungby and is pilot study to automating all current manual soldering. The soldering process accounts for a large part of the processing cost in the production of a heat pump. The process is also a quality risk and has a major impact on the lifetime of the final product.The Main task of this project has been to evaluate automation of the soldering process, to develop automation solutions and a principle layout, to draw the design changes required for the automation and to calculate the supposed solution.This pilot study has resulted in a suggested automation solution using laser as a heat source for soldering. Calculations of the solution show that a automating a laser soldering cell is very profitable..

Most of the saw and pulp industries have stored wood nearby their production, the main reason is to have a continuous wood flow to the production. Wet storage of wood is of great importance to keep the wood quality. Without water sprinkling the risk of drying outand decomposition through biological activity increases significantly and will result in a negative effect on future production and quality. One drawback of wet storage of wood is the leaching of chemical substances into the surrounding recipient. The log yard run-off contains phosphorus, nitrogen, phenols and organic substances. These substances can cause problems for the surrounding environment. The main objective of this project is to gain an understanding of the wet storage used by the Swedish wood industry and estimate the environmental consequences that run-off water will have on the recipient.

The rising demand for electricity and heat raises a big challange for the society and engineers. Many products have been introduced to the market to supply more energy to the energy systems. Absolicon AB is a Swedish company that develops and markets a combined heat and power generating product. The product, Absolicon X10, uses a parabolic trough to concentrate the radiation of the sun onto a receiver. The receiveris equipped with mono crystalline solar cells and is cooled by a circulating liquid media.

Buffer zones play an important role for the water quality in our watercourses. When harvesting a forest close to a watercourse a buffer zone should be left. When it's not left, it will lead to radical changes in the environment for the water organisms. The overall purpose of this thesis was to illuminate the production- and environmental thinking when establishing new buffer zones in south of Värmland. The partials goals were to determine choice of tree species, ways of regenerate, occurrence of soil scarification and the occurrence of machine tracks in newly established buffer zones.