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1117 Uppsatser om Pressure reducing valves - Sida 1 av 75
Expansionsmaskiner istället för strypventiler - en effektivisering
In Uppsala CHP Plant, there are six Pressure reducing valves to reduce the pressure from 15 to 3 bars, before six absorption heat pumps. During the process the energy is conserved but losses occur in form of exergy. The aim of this thesis is to reduce the losses of exergy. This can be done by letting turbines replace the Pressure reducing valves.In this thesis an investigation has been done of the conditions today, the conditions after the change from Pressure reducing valves to turbines and a comparison of three different types of turbine solutions. The three examined solutions are one turbine, several helical screw expanders and several small turbines in parallel with asynchronous generators.The six absorption heat pumps have been divided into two groups; one group of four and one group of two absorption heat pumps.
Kostnadsbesparingar på EM7 : Omkonstruktioner för billigare tillverkning
This thesis describes how a cost reduction project was done on the Packsize ondemand packing machine EM7. The cost reduction was achieved by making minorredesigns of the EM7.The project began by studying the EM7´s structure and function by working on itsassembly line. A short literature study on the subject Design for Manufacturing wasalso done.By working on the assembly line and by speaking with staff from production anddevelopment departments, a number of ideas for reducing manufacturing costs arose.Estimations of the potential cost reduction size for each proposal were done incollaboration with vendors and the purchasing department. Based on the size of the cost reduction, technical risk, impact on the assembly lineand the development time the various proposals were ranked. The two highestranked proposals were selected for further development towards finished solutions.One of the ideas that were selected to develop in to a finished solution meant thatsome of the pneumatic valves were replaced with others.
Diagnos av stiktion i reglerventiler för prediktivt underhåll
This master thesis reviews advances in detection and diagnosis of static friction (stiction) in control valves. Control valves suffering from stiction results in oscillating control loops which in turn decreases both the process stability and reliability. Perstorp AB sees a necessity to automatically detect stiction in valves before the effects of the malfunctioning valves have become too severe. This thesis presents an introduction to maintenance, control loops and how stiction in valves can affect performance of control loops.A selection of methods presented in the literature are introduced and examined using normal operating data from the site in Perstorp. Common for all selected methods is their intuitive ideas and that they are based on normal operating data and minimum amount of process knowledge.
Energikartläggning av avfallsförbränningen i Uppsala
Vattenfall Heat Uppsala runs the waste incineration plant in Uppsala, which produces district heating, process steam, district cooling and electricity. Vattenfall Heat Uppsala has decided to introduce an energy management system with the aim to increase the energy efficiency of the plant. The basis in such a system is to make an energy mapping.In this thesis an energy mapping has been performed at the waste incineration plant with the aim to identify and determine the size of energy flows. The investigated energy flows are used fuel, produced and used steam, produced district heating and cooling. Also the use of electricity to run the processes has been investigated.
Energianalys av tryckluftsystem : så kan Billerud Skärblacka AB spara energi på tryckluft
Compressed air is a low efficiency media, and is thus very expensive to produce. This thesis work began by mind mapping how to create savings on the compressed air system at Billerud Skärblacka AB. Certain issues have been chosen for further studies.In order to identify the consumption of compressed air at PM 8 and 9, several measurements were made. At PM 8 there were not found any pressure drop, only large pressure variations for short periods of time. The causes of these pressure variations were not established.
Fjärrvärmesystem
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.
Utveckling av säte till kulventil SKV
This report contains a degree project made by the mechanical engineering students Lennart Andersson and Daniel Jansson. The project has performed in assignment by SOMAS Valves AB in Säffle. SOMAS are leading in development on control and on/off valves. To maintain this position they always want to improve their products. One way in this development is valves that are more tightened.The purpose with our project was to investigate another seat design on a HiCo (High Cobalt Alloy) seat to a SKV 150 PN 25 valve and compare this to an original HiCo seat.By modifying the seat on a ball valve we want to achieve a valve that leaks lesser then a valve whit original seat.
Turbinkretspump system - Kraftvärmeverket i Borås
The Rya power plant in Borås produces district heating, district cooling and electricity. The plant is owned by Borås Energi och Miljö AB and is run by Dalkia Facility Management AB.In order to get the best heat exchange from the district hot water a pair of twin pumps and a turbine circuit pump are used as return pumps. Turbine circuit pumps are used to increase the pressure through the heat exchangers at the power plant. The pumps are in use when the flow is over 2 000 m3 h-1 and during the summer when re-cooling is used to improve the effectivens of the heat boilers.Since the pumps, that are parallel connected, rotating at a fixed rate per minute, the pressure is regulated with regulating valves. This report shows that during the 4,300 hours that the pumps where in use, energy corresponding to 590 MWh was wasted.
Modellering och simulering av det evaporativa bränslesystemet i en personbil
This thesis work has been performed at the department of diagnosis and dependability at Volvo Car Company, Torslanda. The background of this project is based on interest in ascertaining how different factors possibly can affect a diagnosis method, which has been developed to find leaks in the fuel tank and evaporation system. According to the OBD II requirements leaks with an orifice diameter larger or equal to 0,5 mm, must be detected. The idea of the diagnosis method is to create an over pressure in the system with an air-pump. The current through the pump is measured and correlates to the power consumed by the pump.
Diagnostikmetoder för ångreglerventil med servomotor
In this bachelor thesis, diagnostic methods for one of Siemens stem inlet control valves have been developed. The work has taken place during ten weeks at Siemens Industrial Turbomachinery AB in Finspång. The company produce steam- and gas turbines and also provides service and maintenance. The purpose with this project has been to develop diagnostic methods that oversee the health of the control valves. By using the developed methods you will know when it?s time for maintenance.
CFD simulering av en fyrtakts Otto motorcykel motor
This thesis deals with the numerical 3D simulation of a four stroke, spark-ignited, internalcombustion engine, which is mounted on a high performance motorcycle. The work, carried outin collaboration with Politecnico di Milano and MV Agusta, focuses on the simulation of theintake, compression and expansion stroke, including combustion simulation, using an opensource CFD code.Simulation of internal combustion engines offers a great challenge in the field of CFD research.Moving boundaries of the solution domain, caused by the motion of the piston and valves, leadsto deformation of the computational grid, with decreasing quality of the solution as result. Basedon this, a previously developed mesh motion strategy was employed where a number of meshesare used to cover the whole simulation cycle. Within each mesh interval the internal cell pointsof the mesh are moved to account for the boundary motion of the piston and valves. This strategywas previously applied to simplified geometries as well as real engine geometries.
Trycksårsprevention - en litteraturstudie/Prevention of pressure ulcers - a literature review
Background: Pressure ulcers are a common problem and cause great suffering for those who develop it, and are also an expensive cost to the society. Aim: To describe nursing measures for prevention of pressure ulcers among elderly people in ordinary and nursing homes. Method: A literature review by structured analyze of scientific articles. Result: The analyze resulted in six subjects for prevention of pressure ulcers. These subjects were; risk assesment, nutrition, repositioning, skin/hygiene, nurse knowledge and documentation.
Förekomsten av trycksår hos patienter som genomgår brachybehandling vid prostatacancer
Prostate cancer is the most common cancer in men. One type of treatment is internal radiation therapy, brachytherapy. This treatment requires the patient to lie completely motionless and in lithotomy position. The purpose of this study was to investigate the prevalence of pressure ulcers associated with brachytherapy in prostate cancer at the UniversityHospitalin Uppsala. Furthermore, the purpose was to identify the most common location of pressure ulcer and to examine whether there were any connection between risk factors and possible pressure ulcers.
Stump treatment with the root rot antagonist phlebiopsis gigantea : - sensitivity of P. gigantea spores to high pressure stress; - reduced water consumption for stump treatment
Stump treatment today requires large quantities of clean water mixed with the protective product Rotstop, to fully cover the stump surface. In order to reduce the
water consumption without reducing the coverage of the stump surface, the pressure in the stump treatment device can be increased. Therefore, the Phlebiopsis gigantea
(Fr.) Jül. suspension used as a biological control agent to prevent Heterobasidion annosum (Fr.) Bref. infection was pressure-tested.
Effekten av massagebehanling vid hypertoni : en litteraturstudie
Aim: The aim is to create a review that examines different forms of massage therapy and their effects on hypertension.Method: Literature review of 10 scientific articles on the subject of massage and its effects on blood pressure. The literature searches were made with PubMed and Cinahl using the keywords "massage therapy", "effects" and "blood pressure".Results: The articles showed that massage had a positive effect in lowering blood pressure. This could be explained by greater extent of relaxation in the participants investigated and an increased activity of parasympaticus and reduced secretion of stress hormones. The articles do not agree on what form of massage therapy is most effective in lowering blood pressure and it is uncertain for how long the effect can remain.Conclusion: Massage is usually seen as a treatment without scientific basis. There is evidence that suggests that massage therapy is an effective treatment for lowering blood pressure.