Mondi Dynäs is a pulp and paper producer in the north of Sweden close to the town Kramfors. Last year Mondi Dynäs produced 231,404 tons of Kraft paper. In order to increase their production to 300,000 tons of paper per year this study was done in order to investigate how the increased biomass flow would affect the generation of steam along with the steam and condensate balance. This study started with a mapping of the current steam and condensate balance for one winter period January – Mars and one summer period July – September 2015. The resulting balance is used as reference period for the development of the future steam and condensate scenario where Mondi Dynäs will achieve the targeted production of 300,000 tons of paper per year. The future model shows that the future production of paper will give an abundance of biomass since the generation of steam will be more than sufficient. For the winter period the venting of steam over roof could be derived to 11.9 tons per hour and 34.4 tons per hour during the summer period. This can be compared to the current situation where the winter period gave an average steam blow out of 8.7 tons per hour and for the summer period 13.1 tons per hour. To utilize the accumulated energy from these energy streams, three different scenarios was studied. The first scenario were a future installation of a backpressure turbine along with a condensing turbine section. The new turbine would be attached to the highest pressure level at 65.5 bar and have a backpressure exhaust at 20 bar which will give a power of 7.6 MWe. The second scenario included the implementation of a new condensing turbine with the current system design for the steam network and boilers. This turbine would be attached to the 3.5 bar network and give the electricity power of 1.9 MWe. The third scenario included the installation of a new bark dryer. This would give Mondi Dynäs the possibility to sell bark to an external actor on the energy market. From derived figures in the future scenario model it would be possible to sell 108,144 MWh of bark while running the bark boiler. Mondi Dynäs AB is recommended to add a new condensing turbine to their steam network. The new turbine would be able to produce 1.9 MWe and need a cooling water flow of 190 tons of water per hour. Derived figures for the investment shows a NPV of 0.6 MEUR and the IRR value of 31 %

Den stora användningen av fossil energi i världen är en av orsakerna till de höga utsläppen av koldioxid som förstärker växthuseffekten. För att minska människans klimatpåverkan bör därför mer förnyelsebar energi användas. EU har därför som mål att minska utsläppen av koldioxid med 40 % till år 2030. Industrisektorn står för 32 % av världens totala energianvändning och pappers- och massaindustrin använder 6 % av den energin. I denna studie undersöks Stora Enso Skoghalls Bruk som är ett pappers- och massabruk beläget norr om Vänern. De senaste åren har en rad energieffektiviserande åtgärder utförts där som gjort att det tidvis produceras ett överskott av ånga. I dagsläget friblåses överskottsångan för att hålla trycket på deras ångnät på avsedd nivå. Studiens syfte är att undersöka om elproduktion med hjälp av en kondensturbin är ett lönsamt alternativ för att ta till vara på överskottsångan istället för att friblåsa den. Målet är att ta fram ett beslutsunderlag för dimensionering och bedömning av lönsamhet samt miljöpåverkan för en kondensturbin på Skoghalls Bruk. Studien utfördes genom energitekniska beräkningar i Simulink och en lönsamhetsbedömning genom en nuvärdesanalys. Som grund till beräkningarna ligger driftdata och vetenskaplig litteratur. Scenarier har konstruerats för att avgöra hur både elpriser och koldioxidalstring knuten till den nordiska elmarknaden kan se ut i framtiden. Den samlade bedömningen av studien är att Skoghalls Bruk inte bör investera i en kondensturbin i dagsläget. Låga elpriser i kombination med höga bränslepriser gör att vinsten inte blir tillräckligt hög i förhållande till investeringskostnaden. Vid mer gynnsamma förhållanden, alltså med högre elpriser, lägre bränslekostnader och låg ränta är det mer troligt att investeringen blir lönsam. Investeringen är dock lönsam ur ett miljöperspektiv så länge kondensturbinens elproduktion ersätter någon form av fossil elproduktion i Norden. / The high use of fossil energy in the world is one of the causes of the high emissions of carbon dioxide, which increases the greenhouse effect. In order to reduce the anthropogenic climate impact, more renewable energy should be used. The EU aims to reduce carbon dioxide emissions by 40 % by the year 2030. The industrial sector accounts for 32 % of the total world energy consumption of which the pulp and paper industry uses 6 %. This study examines Stora Enso Skoghall Mill which is a pulp and paper mill located north of Vänern. In recent years, a series of energy efficiency measures has been carried out at Skoghall Mill. At times these measures have resulted in a surplus of steam production. Today this excess steam is released to the atmosphere to maintain the pressure on the steam network at the required level. The purpose of this study is to investigate whether electricity production using a condensing turbine is a profitable alternative for recovery of the excess steam which is currently being released to the atmosphere. The aim is to develop a decision basis for the design and assessment of profitability and environmental impact of a condensing turbine at Skoghall Mill. The study was conducted through energy calculations in Simulink and a profitability assessment by a present value analysis. The basis for the calculations is operational data provided by Skoghall Mill and scientific literature. Scenarios have been designed to determine both how electricity prices and generation of carbon dioxide linked to the Nordic electricity market might look in the future. The overall conclusion of the study is that Skoghall Mill should not invest in a condensing turbine at this time. The profit is not high enough compared to the investment cost due to low electricity prices combined with high fuel costs. In more favourable conditions, i.e. with higher electricity prices, lower fuel costs and lower interest rates, it is more likely that the investment will be profitable. The investment, however, is profitable from an environmental perspective, as long as the electricity from the condensing turbine is replacing fossil power generation in the Nordic region.

The main aim of this diploma thesis is design and calculation of steam condensing turbine with given parameters. In the first part is made calculation of heat balance scheme, which contains high and low pressure regeneration and turbine with total of 5 unregulated steam extraction. It is followed by calculation of regulating stage with impulse blading and calculation of stage part of turbine with reaction blades with total of 27 stages divided to 7 cones. Designes of regulating stage and stage part were checked by calculation of tensile and bending stress. In next parts are calculations of compensating piston and turbine seal system, design of radial and thrust bearings and in the last chapter is shown consumption characteristics of turbine. The designed turbine after optimization at nominal condition has power of 55013,02 kW with thermodynamic efficiency of 83,06 %. The reheat factor of turbine is 1,063. The diploma thesis is supplemented by a conceptual sectional drawing of turbine.

The subject of the thesis is condensing steam turbine with the required power of 50MWe and set input and output parameters. The turbine is designed as a two-body turbine. There is also designed balance scheme with reheating, regeneration and air condenser. Subsequently, the thermodynamic calculation for three variations of high pressure part with different speeds is demonstrated. The result is evaluated in terms of calculated efficiency and also in an economic point of view. The output is a selection of the variation with the best parameters. Then the basic dimensioning calculations, the design of the leveling piston and the sealing system follows for this variation. A simplified section of this part is drawn. Finally, the balance scheme is adjusted based on the data and calculated for limited performance as well.

The aim of this master’s thesis is a retrofit of condensing three case steam turbine K300-170 with reheating. In the first part, the heat balance of the system is calculated for given parameters. The design of the flow section is focused on the combined intermediate pressure and low pressure turbine section and it consists of defining rotor and blading characteristics. In the stress control, the stress of the designed blading is checked and for the conclusion the shaft seal losses and their effect on the overall output power of the turbine are estimated. The drawing of axial section of combined intermediate pressure and low pressure turbine section is also included in the thesis.

The topic of thesis is condensing turbine in gas-steam cycle, which can be divided into four basic parts. A history of gas-steam cycle is described in the beginning. Second part is all about calculation of heat recovery steam generator. Penultimate section deals with calculations of steam turbine parameters and reaction blading type. Last part contains electric power and steam turbine efficiency.

The aim of this thesis is the design of municipal waste incinerator using the generated steam for power generation and distribution of heat. At the beginning is engaged in development of waste issues and the current state of waste management. The next section describes the options of waste treatment and possible solutions to the current state of waste issues. The concept of waste incineration plants: For waste incineration is used line for burning 100,000 tons of municipal waste per year.Combustion takes place in a grate boiler. Its advantage is the versatility and flexibility to waste. Electricity generation is dealt with condensing turbine with controlled consumption. The flue gas cleaning is designed to semi-wet method. The final stage involves the calculation of the balance, the calculation of electric energyand basic economic evaluation.

There is a description of modernisation steam condensing turbine in this Master´s thesis. Electric output is decreased from 250 MW to 160 MW. This thesis is divided into two parts, there is a calculation of heat balance in first part and a calculation of blading in second part. Detail drawing and heat balance are the most important results of this Master´s thesis.

Diploma thesis deals with the design of steam turbine of PBS ENERGO, a.s. company design concept. Condensing turbine is on low steam parameters and of barrel concept. Turbine has two unregulated steam extractions, regulation stage with action blading and seven stages with reaction blading type, which was computed with ca/u method on mean blading diameter. The thesis contains also design of thermic diagram, calculation of axial force on rotor, calculation of steam seals and basic design of longitudinal turbine cross section.

The aim of this master‘s thesis is retrofit of a 300 MW tandem compound steam turbinetype K300 - 170 with three casings and reheat of steam. In the first part a heat balance of the cycle is calculated for given nominal parameters. Further the thesis is focused only on the high pressure section of the turbine, for which the flow section is designed based on thermodynamic calculations and appropriate blade profiles are selected. Then the stress control of the blading is done. The thesis is concluded with estimation of power loss due to shaft seals and real power output of the turbine is calculated. This thesis also includes a drawing of axial section of the high pressure section of the turbine.