An objective of this thesis is to design a grate steam boiler for burning straw. Generated steam will be used for technological purposes or cogeneration. Calculations of the heat comes from engaged temperature and pressure of the overheated steam and characteristics of characteristics of the biomass as well.

This diploma thesis deals with a design of steam boiler used to incineration of mixed municipal waste. Based on the specified fuel and the required output parameters of the steam from a steam boiler is calculated stoichiometry of incineration, thermal losses and overall boiler efficiency. Other chapters of thesis are focused on construction and thermal calculation of boiler moves. Finally, this thesis is to check heat balance of the boiler.

Steam boiler for wood burning 50t/h In this diploma thesis I will deal design of the steam grate boiler 50t/h of burning clean wood. For the specified parameters make a stoichiometric calculations and calculate the enthalpy of the air and combustion. I shall calculate the heat balance, losses of boiler and thermal efficiency of the boiler. The following section make a design of the combustion chamber and its thermal calculation. After determining the dimensions of the combustion chamber further continue by calculating boiler moves and heating surfaces. Finally check the overall heat balance.

The purpose of this Diploma Thesis is the construction design of the steam-boiler for the combustion of biomass – wood pellets. For the specified parameters have been defined stoichiometric calculations and calculations enthalpy burnt gas. In sequence, there is designed and solved the configuraion of the steam-boiler, so that the result design and the number of the heat-delivery surfaces can be determined, in dependence on the required inlet parametres of the air and outlet parametresof the water vapour. These parametres mean the amount, the temparature and the pressure. The aim of the thesis is to make a design of the steam.boiler burning biomass according to the set parametres. This very ecological fuel can really substitute the fossil fuel and friendly respect the environment.

This thesis deals with a project of steam boiler to combustion of refused-derived fuel. With respect of required fuel and output parameters of the steam was worked out stoichiometry, energy loss and boiler efficiency, heat flows was allocate to individual heat exchange surfaces. The heat exchange surfaces was calculate and project in detail.

The aim of a diploma thesis is design of draft boiler for co-firing blast furnace gas and natural gas. In the first part is made the stoichiometric calculation for the gas mixture. Next is the proposal of combustion chamber and proposal of individual heating surfaces of boiler. Next part contains the thermal calculation and control of individual heating surfaces. Part of the work is also drawing documentation of boiler.

Pappers- och massaindustrin är stor i Sverige och dess produkter konsumeras vid hög grad. Eftersom industrin är omfattande och energikrävande är det viktigt att energianvändningen kan optimeras så långt som möjligt. I detta examensarbete utförs en utredning gällande en sodapanna och dess utgående ångtemperatur.  Sodapannan tillhör Mondi Dynäs och utmaningen består i att ångtemperaturen ska ökas från pannan för att maximera energiproduktionen i turbinen, vilket förser hela fabriken med elektricitet och ånga. I dagsläget arbetar sodapannan vid ett tryck på 64,2 bar och 485°C. En ökning av temperaturen och därmed en ökning av entalpin kommer i sin tur möjliggöra ökad elproduktion. Syftet med arbetet är att ta fram förslag till åtgärder som kan implementeras för att öka den utgående ångtemperaturen, samt att lokalisera de komponenter som begränsar temperaturen.     Best Avaliable Techniques (BAT-villkor) för pappersproduktion beskriver hur en sodapanna kan effektiviseras gällande värmeöverförande ytor och elproduktion och dessa punkter användes som vägledning i studien. Med BAT och dess punkter om hur förbättringar kan implementeras samt uppgifter från Mondi Dynäs egna anställda kunde fokus läggas på överhettarna och dess design samt lasten på pannan.    Litteraturstudier utfördes gällande att effektivisera sodapannan och tyngden lades på materialval av överhettartuber för att motverka korrosion och designen av dem. Överhettaren står för 30% av värmeöverföringen och är avgörande för sluttemperaturen av ångan. Därefter gjordes beräkningar för att avgöra om sodapannan är lastad enligt design. Resultatet av studien visar att de föreslagna åtgärderna kan öka ångtemperaturen med 5% vilket motsvarar i en ökning av elproduktion motsvarande 20 miljoner kronor för spotpriset 2023. Studien fastställer även att tubmaterialen som idag används för överhettarna inte är optimala vilket påverkar värmeöverföringen och därmed utgående ångtemperatur, därför rekommenderas nya materialval. Svartlutstillförseln till pannan analyserades också med resultat att den är marginellt underlastad. / The paper and pulp industry is significant in Sweden, with its products being in high demand. Due to the extensive and energy-intensive nature of the industry, optimizing energy usage is crucial. This thesis focuses on investigating a recovery boiler and its outgoing steam temperature. The recovery boiler belongs to Mondi Dynäs, and the challenge is to increase the steam temperature from the boiler to maximize energy production in the turbine, which supplies electricity and steam to the entire factory. Currently, the recovery boiler operates at a pressure of 64.2 bar and 485°C. Increasing the temperature and consequently the enthalpy will enable increased electricity production. The objective of this work is to propose measures that can be implemented to increase the outgoing steam temperature and identify the components limiting the temperature.   The Best Available Techniques (BAT) for pulp production describe how a recovery boiler can be optimized in terms of heat transfer surfaces and electricity production. These points were used as guidance in the study. With BAT and input from Mondi Dynäs employees, the focus was placed on the superheaters and their design, as well as the load on the boiler.   Literature studies were conducted to enhance the recovery boiler, with emphasis on the material selection of superheater tubes to prevent corrosion and their design. The superheater accounts for 30% of heat transfer and is crucial for the final steam temperature. Calculations were then performed to determine if the recovery boiler is loaded according to design.   The results of the study indicate that the proposed measures can increase the steam temperature by 5%, corresponding to an increase in electricity production worth 20 million SEK for the spot price in 2023. The study also establishes that the currently used tube materials for the superheaters are not optimal, affecting heat transfer and the outgoing steam temperature. Therefore, new material choices are recommended. The black liquor supply to the boiler was also analysed, revealing a marginal underload.

Cette thèse a été réalisée en cotutelle entre l'Université Technique Nationale Ivan Pul'uj de Ternopil (TNTU, Ukraine) et l’Université Blaise Pascal (Clermont Ferrand, France). Les travaux ont été effectués au sein de l'Institut Pascal de l’Université Blaise Pascal - Clermont II, de l’IFMA et du CNRS, dans le thème scientifique Matériaux actifs et intelligents, modélisation multi-échelle de l'axe Mécanique, Matériaux et Structures, et au sein de l'Institut Français de Mécanique Avancée. Les travaux réalisés sont inscrits dans l'action transversale « Matériaux et Modélisations Multi-Echelles » de l'Institut Pascal et, en partie, dans l'action MAIM du Laboratoire d'Excellence Labex IMobS3. La thèse présentée appartient au domaine scientifique de la mécanique de la rupture et la science des matériaux.Le but de ce travail est l’étude de l'effet du temps de fonctionnement sur les dommages de la structure, les propriétés mécaniques et la ténacité d'acier de collecteur de surchauffe dans les centrales thermiques et de développer les méthodes qui sont basées sur l'évaluation de la résistance résiduelle du collecteur en tenant compte des dispersions des propriétés mécaniques, du chargement opérationnel et des défauts de taille. La thèse étudie l'influence de l'hydrogénation sur le comportement mécanique, la ténacité et les micro-mécanismes de rupture dans le matériau du collecteur de surchauffe à déformation lente. / This thesis has been performed under the cotutelle agreement between Ternopil Ivan Pul’uj National Technical University (TNTU, Ukraine) and Blaise Pascal University (Clermont Ferrand, France). The thesis has been carried out within Pascal Institute of the Blaise Pascal University - Clermont II, the IFMA and the CNRS, in the Scientific Theme “Active and Smart Materials and Multiscale Modeling” of the Mechanics, Materials and Structures Department, and within the French Institute for Advanced Mechanics. The work is included in the Transversal Action "Materials and Multi-scale Modelling" of the Pascal Institute and in the Action MAIM of the Excellence Laboratory Labex IMobS3. The presented thesis belongs to the scientific field of fracture mechanics and material science. The aim of the thesis is to study the effect of operating time on damage of structure, mechanical properties and fracture toughness of superheater collector steel at thermal power plants (TPPs) and to develop the methods that are based on the assessment of the residual strength of collector taking into account the mechanical properties scatter, operational loading and defect sizes. The thesis studies the influence of hydrogenation on mechanical behavior, fracture toughness and fracture micromechanisms in the material of superheater collector at slow deformation.

The threat of depletion of fossil fuels is the driving force to diversify energy sources in the Czech Republic respectively in the European Union but also worldwide. One of these potential sources are being biomass boilers. The construction of these boilers has expanded in recent years because of government support for the construction of clean energy sources. Whether it is a burning of clean biomass or just incorporation of biomass to fossil fuels, teh substitution of fossil fuels and biomass boilers are the ideal solution. Their major advantages include significant reductions in emissions, mainly sulfur compounds, organic closure of the cycle of CO2 and disposal costs of spent residue.

This thesis deals with a project of steam boiler to combustion of refused-derived fuel. With respect of required fuel and output parameters of the steam was worked out stoichiometry, energy loss and boiler efficiency, heat flows was allocate to individual heat exchange surfaces. The heat exchange surfaces was calculate and project in detail.