Showing papers by "Vattenfall published in 2004"

Investigations on the possibilities of a MISiCFET sensor system for OBD and combustion control utilizing different catalytic gate materials

Abstract: Different catalytic materials, like Pt and Ir, applied as gate contacts on metal insulator silicon carbide field effect transistors—MISiCFET—facilitate the manufacture of gas sensor devices with differences in selectivity, devices which due to the chemical stability and wide band gap of SiC are suitable for high temperature applications. The combination of such devices in a sensor system, utilizing multivariate analysis/modeling, have been tested and some promising results in respect of monitoring a few typical exhaust and flue gas constituents, in the future aiming at on board diagnostics (OBD) and combustion control, have been obtained.

A method and a device for slowing down and disintegrating a plug of liquid plunging forward in a duct

Abstract: In a first aspect the invention relates to a device for slowing down and disintegrating a plug of liquid plung­ing forward in a duct. The device comprises a container (1) having a bottom (5) and an opposite inlet (2), which is connectable to the duct and through which the plug of liquid can be directed into a central, axial trajectory (A) in the container. Inside the container, an inner tube (7), being open towards the bottom, is arranged, which tube separates an inner hollow space (8) from an outer, cross section-wise ring-shaped hollow space (9), a distributor body (13) being arranged in the trajectory of the entering plug of liquid with the purpose of splitting and disinte­grating the plug of liquid as well as throwing out the dis­integrated constituent parts of liquid in the direction outwards from the centre. The bottom (5) comprises a con­cavely curved guide surface (16) with the purpose of diver­ting the liquid from one of the hollow spaces to the other in order to, in this way, reverse the direction of motion of the liquid. In a second aspect the invention relates also to a method of slowing down and disintegrating a plug of liquid plunging forward in a duct.

Transportation infrastructure for CCS - Experiences and expected development

Abstract: Publisher Summary For commercialization of CO 2 Capture and Storage (CCS) from fossil-fuelled power plants, an infrastructure for the transportation of captured carbon dioxide (CO 2 ) from the sources of emission to the storage sites is required. This chapter illustrates the way a CCS transportation infrastructure can be developed by applying pipeline and ship transportation. It summarizes the experiences and critical design criteria for the pipeline and ship transportation of CO 2 and identifies and analyses type scenarios based on these modes of transportation. For a large power station located far from the disposal site, a single pipeline from source to sink cam be used. A single network is, however, believed to have an upper capacity limit because single storage regions will have upper limits in receiving rate. If several power stations can use a coordinated network, the transportation costs can be lowered. Such a coordinated network can also include ship transportation. Ships are more flexible than pipelines when it comes to the adaptability of capacity and transportation route, and a transportation system including both ships and pipeline will, therefore, make the infrastructure more adaptable to the variations in the infrastructure of the storage location.

METHOD AND ARRANGEMENT FOR PRODUCING $g(a)-CALCIUM SULPHATE HEMIHYDRATE USING THE GYPSUM SUSPENSION PRODUCED DURING THE WET FLUE GAS DESULPHURIZATION OF A FOSSIL-FIRED THERMAL POWER STATION

Abstract: not available for EP1183216Abstract of corresponding document: DE19908776The invention relates to a method and an arrangement for producing alpha -calcium sulphate hemihydrate using the gypsum suspension produced during the wet flue gas desulphurization process of a fossil-fired thermal power station. The aim of the invention is to carry out a continuous process of converting and further processing gypsum to produce highly pure end products which is directly linked to the flue gas desulphurization process of a coal-fired power station. To this end, a partial flow is removed from the gypsum suspension taken from the flue gas desulphurization process (1) before dehydration and the solid parts are separated into dihydrate and unwanted constituents by one or more hydrocyclones (5). The thus purified suspension is heated, then mixed with a dispersion of crystallizers and nucleators (11), guided via the outer pipe (13) of a longitudinal, upright double-pipe heat exchanger (14) and after being heated again, is released to an optionally coil-shaped reactor (19) which is located underneath which has mixing screws, using the hydrostatic pressure. The suspension is then delivered to the inner pipe (21) of the double-pipe heat exchanger (14). The resulting alpha -calcium sulphate hemihydrate suspension in this inner pipe (21) is caused to rise to the exit level (22) and then dehydrated, the resulting powder then being dried and screened or ground. The invention also relates to an arrangement for producing alpha -calcium sulphate-hemihydrate using the gypsum suspension produced in the wet flue gas desulphurization plant of a fossil-fired thermal power station.

Lime slaking reactor for power station water treatment system, has intermittently-operated high pressure water jets directed at reactor dome and upper sidewalls

Abstract: A power station has a self-cleaning water treatment lime slaking reactor (1) with shaft-driven mixer paddles (4). In a process to scour-clean the reactor, water is introduced under pressure into a rotating feed-pipe (5) and then directed via angled discharge jets (10) at the reactor dome and sidewalls. The water is introduced to the feed pipe (11) at a pressure of from 2 to 7 bar. Also claimed is a commensurate self-cleaning lime slaking reactor incorporating spray jets.

Steam generator heating surface comprising a multitude of approximately parallel heating tubes through which a cooling agent passes

Abstract: not available for EP1402214Abstract of corresponding document: DE10131524The invention relates to a heating surface of a steam generator comprising a multitude of approximately parallel heating tubes through which a cooling agent passes. Said heating tubes are arranged in the flow channel of the steam generator by means of mountings. The aim of the invention is to embody the heating surfaces of the steam generator in such a way as to prevent the continuous build-up of deposits in the form of slagging, and the disadvantages associated therewith, in the area through which the flue gases pass. To achieve this, the heating surface tubes are surrounded by protective sleeves which rest loosely on the surface of the heating surface tubes between the mountings thereof. The ends of the protective sleeves exhibit an expansion distance to the mountings of the heating surface tubes. The heat expansion coefficient of the material forming the protective sleeves is higher than that of the material forming the heating surface tubes.

In search of stability : investigating flexible and stable production strategies for an optimised steel plant

Abstract: Increased global competition and growing environmental concerns around the world are two major trends affecting companies today. Tougher competition has led companies to focus primarily on their core business activities, which may lead to a shortage of resources for support activities, such as energy management. This development takes place while environmental concerns step up requirements regarding companies' environmental performance, with global warming at the forefront. Together these issues have increased the management complexity and thus the need for relevant decision support. The purpose of this thesis is to study ways to reach a more comprehensive view of industrial energy systems than is the case today, and thereby achieve more efficient systems.One theme in this thesis is to investigate analysis approaches, mainly based on optimisation, that can help to produce a comprehensive view of industrial energy systems. The subject of the studies was an integrated steel plant in Sweden which has a connected CHP plant that uses the excess process gases from the steel plant as fuel. The studies included analyses of the operation planning during both internal process variations and changed external conditions. They also included analyses of relations between objectives such as cost, energy use, and environmental performance by applying a multi-objective approach. The analyses proved to provide a comprehensive view of how the system reacts to various changes, which factors are the essential ones for different objectives, and what trade-offs can be made between the objectives.In addition to this, two studies were conducted of energy-related co-operations between companies. The first looked at co-operation where energy service companies bring competence and other resources related to energy efficiency to the pulp and paper industry. The main aspects of concern were: the managers' views on the opportunities and risks with energy-related co-operation; and its implications for industrial energy management. The second study investigated co-operation between process industries and municipal energy companies with regard to indus trial waste heat deliveries and jointly owned combined heat and power plants. The study emphasised incentives for and barriers to this kind of co-operation. In both studies it was found that trust between the parties is important, that the form of the contract is also important especially to bring the focus to bear on common benefits rather than just one's own, and to reduce the risks involved in co-operation.Based on the performed studies possible implications of decision support based on optimisation and co-operation between companies are discussed.

Legerohr zum Verteilen und Speichern von Flüssigkeit

Abstract: Legerohr zum Verteilen und Speichern einer einstromenden Flussigkeit mit einer beliebigen Temperatur in einem fur die Flussigkeit vorgesehenen Speichertank (3), in dem die gespeicherte Flussigkeit aufgrund sich unterscheidender Dichten auf verschiedenen Temperaturniveaus geschichtet wird, wobei das Legerohr (7), so ausgebildet ist, dass es sich vertikal durch die im Tank gespeicherte Flussigkeit erstreckt und ein Einstromende und eine Ausstromoffnung umfasst, die mit einer Ruckschlagventilvorrichtung versehen ist, die ein Ausstromen der Flussigkeit in den Tank erlaubt, aber ein Einstromen vom Tank in das Legerohr verhindert, dadurch gekennzeichnet, dass die Ausstromoffnung die Form einer langlichen Offnung oder Schlitzes (8) hat, die beziehungsweise der sich in longitudinaler Richtung des Legerohrs (7) und im wesentlichen langs der gesamten Langenausdehnung des besagten Legerohrs erstreckt und dass die Ruckschlagventilvorrichtung ein langliches flexibles Element (11) umfasst, das relativ zum Legerohr langs einer Linie oder eines Bereichs parallel zur longitudinalen Ausdehnung der Ausstromoffnung befestigt ist und welches durch sich...

Process and device to reduce the feed water temperature in a container for a steam generator in a thermal power unit uses gradual change to avoid loss of power

Abstract: A process for reducing the feed water temperature in a container for a steam generator in a thermal power unit especially by changing from turbo (5) to electric (4) boiler pumps comprises instead gradually feeding hot vapor condensate (2) directly to components and systems of a steam generator so that there is no loss of power. An Independent claim is also included for a device for operating the above process.

Arrangement for repairing flaps in a shaft, especially cold air flaps in a coal drop shaft, has transportable partitioning system in the coal drop shaft at the level of two opposing control hatches

Abstract: The arrangement has a transportable partitioning system (1) in the coal drop shaft (3) at the level of two opposing control hatches (6), whereby an angled element is attached to the two control hatches' flanges (6) by a reversible connection. Partition plates are attached to pipes in pipe holders on both angled elements.

Reducing and purifying chloride particle load in stack gas desulfurizing plants, comprises removing stream of mud in the plant, and admitting mud across multi-material nozzles to gas stream after generator and before electrostatic filter

Abstract: The stream is used as a propellant. A hydro cyclones is isolated from an oxidation circuit stack gas gypsum across the under flowing of hydro cyclones and salts.