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117 Uppsatser om Steam Valve - Sida 1 av 8

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.

Återväxt av blåbär (Vaccinium myrtillus L.) efter ångbehandling : orsaker till effektiv kontroll

Steam was used as a site preparation method to eliminate unwanted bilberry (Vaccinium myrtillus L.) in the boreal forest. The efficiency of steam to suppress bilberry was compared with prescribed burning and cutting the bilberry. Different combinations of steaming and/or cutting the bilberry were set up to investigate in which way steaming and cutting influenced the sprouting and regrowth of bilberry. The regrowth of the bilberry vegetation was monitored for 40 month. Steam was most efficient in suppressing bilberry.

Ångsterilisering av morötter. Infekterade med Lactobacillus plantarum.

The purpose of the project was to exam steams ability to sterilize carrots infected withLactobacillus plantarum. The project was a cowork with Brämhults Juice AB. They hadobserved an increase of Lactobacillus in the production of carrot juice during the summer. Tokeep the flavour of fresh fruits, the juice is treated carefully with heat. This means that thejuice only stays fresh for a few days, around two weeks for an unopened package and threedays for an opened package.In an attempt to remove the remaining Lactobacillus of the carrots, steam is tested as an extrastep in the production of juice.

Interdependence between seed age and aerated steam treatment intensities

Aerated steam treatment is a modern and environmental friendly method for seed borne fungus sanitation, mainly used on cereals. The method involves exposure to heat and high humidity, factors which are known to induce a fast ageing of seeds, thus resulting in reduced storability. This thesis clarifies the interdependence between seed age and the aerated steam treatment intensities. Two studies were carried out in this thesis. In the first study the storage longevity of seeds treated with aerated steam was examined. The second study investigated the shelf-life of the pre-tests used to determine the aerated steam treatment tolerance of a seed lot, by testing the treatment tolerance of seeds aged prior to the treatment.

Aktiv ventilstyrning

To achieve an optimal combustion, an even air/fuel ratio in the combustion chamber is required. An optimal combustion leads to reduced amount of emissions due to a more complete combustion, which is an important matter because of the sharpened environmental laws. This can be attained, among other things, by applying entirely variable cam times. To optimize the engines efficiency and its emissions at all workloads and speeds, an active valve control can be applied. This means that the intake and exhaust-valves can be opened and closed at any time, independent of the crankshaft position.

VVA-strategier för avgastemperaturhöjning på en HD-Dieselmotor

Regulations on the exhaust emissions of HD-diesel engines are becoming more and more stringent, and therefore, emission after-treatment systems are commonly used. These systems rely on catalytic conversion of NOx,CO , and HC emissions, and are thus dependant on temperature. At low load of the engine, exhaust temperatures are not sufficient for the after-treatment components. Therefore, means to increase the exhaust temperature while maintaining low emissions and fuel consumption are needed.The focus of this project has been to develop strategies for the lift profiles of exhaust and intake valves in the engine, with the goal to raise exhaust temperature in combination with low emissions and fuel consumption. The strategies have been tested in a single-cylinder research engine equipped with a hydraulic variable valve actuation system.

Val av överlastskydd för elektriska ventilmanöverdon på kärnkraftverket i Forsmark

At nuclear power plants, electrical valve actuators are important for ensuring that the reactor core is water covered and the pressure in the reactor tank and containment is limited. The electrical actuators are provided with overload protection in case of drawing higher current then the motors are rated for. When safety manoeuvres are needed, the overload protection must not trig and cause the valve to stop before completing the manoeuvre. Analyses have showed that the current settings of the overload protection may cause an illegitimate trig at the worst theoretically possible accident. A new method has been developed with conservative assumptions and applies overload protections for all electrical valve actuators at the three reactors in Forsmark..

Mean value modelling of a poppet valve EGR-system

Because of new emission and on board diagnostics legislations, heavy truck manufacturers are facing new challenges when it comes to improving the engines and the control software. Accurate and real time executable engine models are essential in this work. One successful way of lowering the NOx emissions is to use Exhaust Gas Recirculation (EGR). The objective of this thesis is to create a mean value model for Scania's next generation EGR system consisting of a poppet valve and a two stage cooler. The model will be used to extend an existing mean value engine model.

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.

Profilen och jag : En studie av användarprofiler och identitet på Steam

Internet och sociala medier har lett till att användare har fått möjligheter att dela med sig av information som i sin tur får representera dem i de olika virtuella miljöerna. Bland annat finns Steam som är en spelplattform med möjlighet att skapa samt ändra användarprofiler. Men varför väljer aktiva användare av Steam som har ändrat sin användarprofil att ändra den?Efter en enkätundersökning med svar från 50 deltagande skapades en uppfattning om användares valmöjligheter samt användning av olika funktioner som tillät användare dela med sig av information om sig själva via Steam. Därefter anordnades semistrukturerade intervjuer där deltagares svar ledde till diskussion kring olika begrepp som skulle kunna förklara anledningar till användandet av funktionerna på användarprofilerna.Resultaten i denna studie visade att de olika begrepp som beskriver varför användare väljer att ändra sina profiler är virtuell identitet, anonymitet och socialt kapital.

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.

Modellering och reglering av mjölkningsrobot

In this master thesis a robot arm belonging to an automatic milking machine from DeLaval is investigated. The robot arm is controlled by a pneumatic cylinder and a valve. The goal of the master thesis is to investigate instability problems and to find out if it is possible to solve them by using gain scheduling. Gain scheduling is a type of controller where the parameters of the controller are changed during operation, for example depending on the working point. First a nonlinear mathematical model of the system was made.

Omkonstruktion av testrigg för småskalig ångsmotor

The actual project presents the development of a testing rig for a steam engine. A short overviewabout the development of steam engines is presented, until arriving to the development of thepresent engine, which will require to be tested in different ways.The testing rig studied on this project (based on a Lanchester engine) will be used to testdifferent materials and layouts for the group Piston-Cylinder.The engine is a high performance steam power engine, which is going to have a highpower/dimensions ratio, what will lead to require high performance components and materials.An introduction to the testing rig is presented, and the entire design project is done in order toreplace the disappeared documentation of the current testing rig, built on the 1970?s. Also somemodifications done in the original testing rig are presented, as well as some detected problemsand their possible solutions..

Aortainsufficiens hos häst : patofysiologi och behandling

Aortic insufficiency is a very common valve problem in horses and most often affects older individuals, but nevertheless existent within younger ones. The root cause for aortic insufficiency can be varied, for example; endocarditis, ventricular septum defect or congenital valve disease but the most common are progressive valve degeneration or elite competition. Depending on the root cause, different changes can be observed on the aorta valves, but they do all have the same effect, the valves do not seal properly and blood leaks backwards. Many horses can, even with this deficiency, perform highly without any visible impacts and there is therefore no need to treat those subjects. Most often the symptoms arise at a later stage in life and they are, more often than none, put down for other reasons. In the occurrence of the clinical symptoms showing, treatment guideline is to inhibit these symptoms since the valve degeneration is presently irreversible.

Utveckling av hygienfunktioner i diskmaskiner : Desinfektion med ånga

This report is the result of a thesis work in Integrated Product Development, regarding hygienic features in dishwashers and especially disinfection by the use of steam.The thesis is performed at Electrolux Primary Development Dishcare in Stockholm and in collaboration with the Department of Machine Design at the Royal Institute of Technology.The targets of the thesis are to prove the advantages of a technology suitable to implement as a hygienic feature inside a dishwasher and to realize a functional prototype of a differentiated hygienic feature that does not exist on the market today.The process followed to perform the thesis is the process defined for Electrolux Primary Development.The technology chosen for development is disinfection by heating the water on the surface of the dishware, by the use of steam.A number of tests on how steam behaves when injected into the dishwasher tub have been performed, providing the results that have been taken in consideration when designing the prototype.The prototype consists of a pipe system provided with nozzles to eject the steam into the upper parts of the dishwasher. Tests of the final prototype show that thermal disinfection of water in a dedicated area of the tub can be reached within 9 minutes. The operation requires 0,17 liters of water and consumes 0.2kWh..

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