Este trabalho avalia as propriedades mecânicas, microestrutura resultante e força de estampagem da liga DIN 27MnCrB5 para o processo de estampagem a quente nas temperaturas de aquecimento de 750°C, 850°C e 950°C. Para isso foram realizados ensaios nas três temperaturas e medidos os valores da força necessária para a estampagem da chapa, que foi aplicada em uma área de 30mm x 1,50mm. A partir da peça estampada foram realizadas análises metalográficas da microestrutura resultante e medições de dureza para a correlação com as propriedades mecânicas. Para as temperaturas de aquecimento de 750°C e 850°C não foi verificada microestrutura martensítica nas peças estampadas. Para o ensaio realizado com uma temperatura de aquecimento de 950°C ocorreu transformação martensítica na peça na região que esteve em contato com o prensa chapa e a matriz. Esta transformação metalúrgica resultou em valores de dureza de 715±17HV0,2 em comparação com a condição inicial da chapa, cuja dureza era de 187±5HV0,2. As medições de força de estampagem para as três temperaturas de ensaio indicam uma redução da força com o aumento da temperatura de aquecimento da chapa. Para a temperatura de aquecimento da chapa de 750°C o valor médio da força de estampagem foi de 14kN, para a temperatura de 850°C o valor médio da força de estampagem foi de 9kN, enquanto para a temperatura de 950°C foi encontrado o valor médio de 5kN. / This work evaluates the mechanical properties, resulting microstructure and stamping force of the DIN 27MnCrB5 alloy for the hot stamping process at the heating temperatures of 750°C, 850°C and 950°C. For this, tests were carried out at the three temperatures and the values of the force required for the stamping of the sheet were measured, which was applied in an area of 30mm x 1,50mm. From the stamped part metallographic analyzes of the resulting microstructure and hardness measurements were performed for the correlation with the mechanical properties. For the heating temperatures of 750°C and 850°C, no martensitic microstructure was observed in the stamped parts. For the test performed with a heating temperature of 950°C martensitic transformation occurred in the part in the region that was in contact with the blank holder and the die. This metallurgical transformation resulted in hardness values of 715±17HV0,2 compared to the initial condition of the sheet, whose hardness was 187±5HV0,2. Stamping force measurements for the three test temperatures indicate a reduction in force with the increase of the sheet heating temperature. For the sheet heating temperature of 750°C the average value of the stamping force was 14kN, at the temperature of 850°C the average value of the stamping force was 9kN, while at the temperature of 950°C it was found The average value of 5kN.

Este trabalho avalia as propriedades mecânicas, microestrutura resultante e força de estampagem da liga DIN 27MnCrB5 para o processo de estampagem a quente nas temperaturas de aquecimento de 750°C, 850°C e 950°C. Para isso foram realizados ensaios nas três temperaturas e medidos os valores da força necessária para a estampagem da chapa, que foi aplicada em uma área de 30mm x 1,50mm. A partir da peça estampada foram realizadas análises metalográficas da microestrutura resultante e medições de dureza para a correlação com as propriedades mecânicas. Para as temperaturas de aquecimento de 750°C e 850°C não foi verificada microestrutura martensítica nas peças estampadas. Para o ensaio realizado com uma temperatura de aquecimento de 950°C ocorreu transformação martensítica na peça na região que esteve em contato com o prensa chapa e a matriz. Esta transformação metalúrgica resultou em valores de dureza de 715±17HV0,2 em comparação com a condição inicial da chapa, cuja dureza era de 187±5HV0,2. As medições de força de estampagem para as três temperaturas de ensaio indicam uma redução da força com o aumento da temperatura de aquecimento da chapa. Para a temperatura de aquecimento da chapa de 750°C o valor médio da força de estampagem foi de 14kN, para a temperatura de 850°C o valor médio da força de estampagem foi de 9kN, enquanto para a temperatura de 950°C foi encontrado o valor médio de 5kN. / This work evaluates the mechanical properties, resulting microstructure and stamping force of the DIN 27MnCrB5 alloy for the hot stamping process at the heating temperatures of 750°C, 850°C and 950°C. For this, tests were carried out at the three temperatures and the values of the force required for the stamping of the sheet were measured, which was applied in an area of 30mm x 1,50mm. From the stamped part metallographic analyzes of the resulting microstructure and hardness measurements were performed for the correlation with the mechanical properties. For the heating temperatures of 750°C and 850°C, no martensitic microstructure was observed in the stamped parts. For the test performed with a heating temperature of 950°C martensitic transformation occurred in the part in the region that was in contact with the blank holder and the die. This metallurgical transformation resulted in hardness values of 715±17HV0,2 compared to the initial condition of the sheet, whose hardness was 187±5HV0,2. Stamping force measurements for the three test temperatures indicate a reduction in force with the increase of the sheet heating temperature. For the sheet heating temperature of 750°C the average value of the stamping force was 14kN, at the temperature of 850°C the average value of the stamping force was 9kN, while at the temperature of 950°C it was found The average value of 5kN.

Este trabalho avalia as propriedades mecânicas, microestrutura resultante e força de estampagem da liga DIN 27MnCrB5 para o processo de estampagem a quente nas temperaturas de aquecimento de 750°C, 850°C e 950°C. Para isso foram realizados ensaios nas três temperaturas e medidos os valores da força necessária para a estampagem da chapa, que foi aplicada em uma área de 30mm x 1,50mm. A partir da peça estampada foram realizadas análises metalográficas da microestrutura resultante e medições de dureza para a correlação com as propriedades mecânicas. Para as temperaturas de aquecimento de 750°C e 850°C não foi verificada microestrutura martensítica nas peças estampadas. Para o ensaio realizado com uma temperatura de aquecimento de 950°C ocorreu transformação martensítica na peça na região que esteve em contato com o prensa chapa e a matriz. Esta transformação metalúrgica resultou em valores de dureza de 715±17HV0,2 em comparação com a condição inicial da chapa, cuja dureza era de 187±5HV0,2. As medições de força de estampagem para as três temperaturas de ensaio indicam uma redução da força com o aumento da temperatura de aquecimento da chapa. Para a temperatura de aquecimento da chapa de 750°C o valor médio da força de estampagem foi de 14kN, para a temperatura de 850°C o valor médio da força de estampagem foi de 9kN, enquanto para a temperatura de 950°C foi encontrado o valor médio de 5kN. / This work evaluates the mechanical properties, resulting microstructure and stamping force of the DIN 27MnCrB5 alloy for the hot stamping process at the heating temperatures of 750°C, 850°C and 950°C. For this, tests were carried out at the three temperatures and the values of the force required for the stamping of the sheet were measured, which was applied in an area of 30mm x 1,50mm. From the stamped part metallographic analyzes of the resulting microstructure and hardness measurements were performed for the correlation with the mechanical properties. For the heating temperatures of 750°C and 850°C, no martensitic microstructure was observed in the stamped parts. For the test performed with a heating temperature of 950°C martensitic transformation occurred in the part in the region that was in contact with the blank holder and the die. This metallurgical transformation resulted in hardness values of 715±17HV0,2 compared to the initial condition of the sheet, whose hardness was 187±5HV0,2. Stamping force measurements for the three test temperatures indicate a reduction in force with the increase of the sheet heating temperature. For the sheet heating temperature of 750°C the average value of the stamping force was 14kN, at the temperature of 850°C the average value of the stamping force was 9kN, while at the temperature of 950°C it was found The average value of 5kN.

The master´s thesis contained basic information about the method of thermodynamic efficiency of hydraulic machines. The first part briefly mentioned our opinion on the most widely used method for determining the efficiency of hydraulic machines. Another section of thesis is characterization and measurement procedure using the thermodynamic method. Another section describes measurements of water plants and laboratory measurements, which took place in the past. The final part describes the results of laboratory measurements, which took place in the lab of VUT FSI Brno, and evaluating and comparing the results.

The thesis deals with a draft production procedure for a specific welded component of a bearing console, including the consideration of the basic material welding quality, the selection of welding method and parameters, thermal processing, if applicable, and the selection of filler material. Draft welding procedure of WPS and weld check. Consideration of the use of a robot.

Sodium dithionite (Na2S2O4) is a powerful reducing agent. It has therefore been suggested to be used as an additive in kraft pulping to improve the yield. However, sodium dithionite easily decomposes and it is thus important to determine the effect of different conditions. The aim of this thesis has been to investigate the thermal stability of sodium dithionite under anaerobic conditions using ATR-FTIR spectroscopy under different conditions, such as heating temperature, concentration of the solution, heating time and pH. The stability of sodium dithionite was found to decrease with increasing heating temperature, concentration of sodium dithionite, heating time and pH. Sodium dithionite was found to be relatively stable at moderate alkaline pH:s 11.5 and 12.5, while a rapid decrease in stability with time was noted at higher heating temperatures and concentrations of sodium dithionite. Based on this study on the thermal stability of sodium dithionite, the following conditions are suggested as the most promising, when adding sodium dithionite to the kraft cooking as an additive; pH 12.5, with 0.4 M concentration of the solution, at a heating temperature of 100 °C.

Bei der Auslegung und Überprüfung der Betriebsweise von Fernwärmesystemen (FWS) ist eine Analyse der gesamten Prozesskette eines FWS – Erzeugung, Verteilung und Übergabe – notwendig, um eine bestmögliche Gestaltung derselben zu erreichen. Einen Ansatz zur Optimierung der Betriebsweise bietet die Modifikation des Fernwärmetemperaturniveaus, dem in der Fernwärmebranche bezüglich der Wirtschaftlichkeit des Gesamtsystems eine große Bedeutung beigemessen wird. Allgemeingültige Aussagen zur Höhe dieses Einflusses lassen sich aufgrund der unterschiedlich gestalteten FWS, insbesondere für Teillastbedingungen, nicht treffen. Die vorliegende Arbeit behandelt den Einfluss des Fernwärmetemperaturniveaus auf die Effizienz thermodynamischer Prozesse in Anlagen der Kraft-Wärme-Kopplung (KWK-Anlagen) mit Dampfturbinen sowie auf den Transportaufwand des Fernwärmewassers. Zu diesem Zweck werden die Grundlagen und der Stand des Wissens sowie wesentliche Zusammenhänge zwischen den Optimierungsstrategien und dem Fernwärmetemperaturniveau formuliert. Zur Ermittlung des elektrischen Eigenbedarfs für den Transport des Fernwärmewassers wird eine hydraulische Untersuchung vorgestellt und anhand unterschiedlicher Wärmenetzstrukturen diskutiert. Für die weitere Analyse von KWK-Anlagen mit Dampfturbinen werden methodische Hinweise und Grundlagen zur Modellierung ausgearbeitet, die anschließend auf real existierende typische KWK-Anlagen angewendet werden. Dies sind eine Gegendruckanlage, ein Kombikraftwerk und eine Entnahme-Kondensations-Anlage. Zur Modellüberprüfung werden Mess- und Simulationswerte von ausgewählten Lastgängen sowie für den gesamten Lastbereich gegenübergestellt. Zur Bewertung der Energieeffizienz von FWS unter Berücksichtigung des Fernwärmetemperaturniveaus werden zwei Methoden abgeleitet. Eine differentielle, auf den Lastpunkt bezogene Bewertung mittels temperaturabhängiger Kraftwerkskennlinien und eine integrative Bewertung, bei der unterschiedliche Betriebsweisen über einen definierten Zeitraum einbezogen werden. An ausführlichen Beispielen werden deren Anwendung und Eignung sowie der Einfluss des Fernwärmetemperaturniveaus diskutiert. Abschließend wird die Wirtschaftlichkeit von 3 ausgewählten Maßnahmen durch Anwendung der integrativen Bewertung vorgestellt. / In order to achieve the best possible end-to-end design of a district heating system, any dimensioning and examining of operating regimes of district heating systems requires an analysis of the entire process chain ranging from generation via distribution to heat delivery. One of the options to optimise an operating regime is to modify the district heating temperature level, a parameter to which great importance is attached in the district heating industry with a view to the economics of the overall system. The differences in the design of district heating systems do not allow issuing any universally valid statements on how strong this influence is, especially for conditions of part load. The present paper looks into the influence of the district heating temperature level on the efficiency of thermodynamic processes in combined heat and power (CHP) plants using steam turbines, and on the expenditure of district heating water transport. For this purpose, it states the fundamentals and current level of knowledge, as well as important connections between the optimisation strategies used and the district heating temperature level. In view of calculating the auxiliary power required to transport district heating water, a hydraulic analysis will be presented and discussed, with several different structures of district heating systems being used for illustration. For a more advanced analysis of CHP plants using steam turbines, methodological information and modelling basics will be described and then applied to typical CHP plants existing in reality. These are a backpressure plant, a combined-cycle gas turbine plant and an extraction condensing plant. To validate the model, measured and simulated data of selected load cycles as well as the entire load range will be compared. Two methods of assessing the energy efficiency of district heating systems in consideration of the district heating temperature level will be derived: a differential assessment related to the duty point and using temperature-dependent power plant characteristic curves, and an integrative assessment where several different operating regimes are included over a pre-defined period of time. Detailed examples will be discussed to illustrate the application and suitability of these assessments as well as the influence of the district heating temperature level. Finally, the economics of selected steps applying the integrative assessment will be highlighted.

Bei der Auslegung und Überprüfung der Betriebsweise von Fernwärmesystemen (FWS) ist eine Analyse der gesamten Prozesskette eines FWS – Erzeugung, Verteilung und Übergabe – notwendig, um eine bestmögliche Gestaltung derselben zu erreichen. Einen Ansatz zur Optimierung der Betriebsweise bietet die Modifikation des Fernwärmetemperaturniveaus, dem in der Fernwärmebranche bezüglich der Wirtschaftlichkeit des Gesamtsystems eine große Bedeutung beigemessen wird. Allgemeingültige Aussagen zur Höhe dieses Einflusses lassen sich aufgrund der unterschiedlich gestalteten FWS, insbesondere für Teillastbedingungen, nicht treffen. Die vorliegende Arbeit behandelt den Einfluss des Fernwärmetemperaturniveaus auf die Effizienz thermodynamischer Prozesse in Anlagen der Kraft-Wärme-Kopplung (KWK-Anlagen) mit Dampfturbinen sowie auf den Transportaufwand des Fernwärmewassers. Zu diesem Zweck werden die Grundlagen und der Stand des Wissens sowie wesentliche Zusammenhänge zwischen den Optimierungsstrategien und dem Fernwärmetemperaturniveau formuliert. Zur Ermittlung des elektrischen Eigenbedarfs für den Transport des Fernwärmewassers wird eine hydraulische Untersuchung vorgestellt und anhand unterschiedlicher Wärmenetzstrukturen diskutiert. Für die weitere Analyse von KWK-Anlagen mit Dampfturbinen werden methodische Hinweise und Grundlagen zur Modellierung ausgearbeitet, die anschließend auf real existierende typische KWK-Anlagen angewendet werden. Dies sind eine Gegendruckanlage, ein Kombikraftwerk und eine Entnahme-Kondensations-Anlage. Zur Modellüberprüfung werden Mess- und Simulationswerte von ausgewählten Lastgängen sowie für den gesamten Lastbereich gegenübergestellt. Zur Bewertung der Energieeffizienz von FWS unter Berücksichtigung des Fernwärmetemperaturniveaus werden zwei Methoden abgeleitet. Eine differentielle, auf den Lastpunkt bezogene Bewertung mittels temperaturabhängiger Kraftwerkskennlinien und eine integrative Bewertung, bei der unterschiedliche Betriebsweisen über einen definierten Zeitraum einbezogen werden. An ausführlichen Beispielen werden deren Anwendung und Eignung sowie der Einfluss des Fernwärmetemperaturniveaus diskutiert. Abschließend wird die Wirtschaftlichkeit von 3 ausgewählten Maßnahmen durch Anwendung der integrativen Bewertung vorgestellt. / In order to achieve the best possible end-to-end design of a district heating system, any dimensioning and examining of operating regimes of district heating systems requires an analysis of the entire process chain ranging from generation via distribution to heat delivery. One of the options to optimise an operating regime is to modify the district heating temperature level, a parameter to which great importance is attached in the district heating industry with a view to the economics of the overall system. The differences in the design of district heating systems do not allow issuing any universally valid statements on how strong this influence is, especially for conditions of part load. The present paper looks into the influence of the district heating temperature level on the efficiency of thermodynamic processes in combined heat and power (CHP) plants using steam turbines, and on the expenditure of district heating water transport. For this purpose, it states the fundamentals and current level of knowledge, as well as important connections between the optimisation strategies used and the district heating temperature level. In view of calculating the auxiliary power required to transport district heating water, a hydraulic analysis will be presented and discussed, with several different structures of district heating systems being used for illustration. For a more advanced analysis of CHP plants using steam turbines, methodological information and modelling basics will be described and then applied to typical CHP plants existing in reality. These are a backpressure plant, a combined-cycle gas turbine plant and an extraction condensing plant. To validate the model, measured and simulated data of selected load cycles as well as the entire load range will be compared. Two methods of assessing the energy efficiency of district heating systems in consideration of the district heating temperature level will be derived: a differential assessment related to the duty point and using temperature-dependent power plant characteristic curves, and an integrative assessment where several different operating regimes are included over a pre-defined period of time. Detailed examples will be discussed to illustrate the application and suitability of these assessments as well as the influence of the district heating temperature level. Finally, the economics of selected steps applying the integrative assessment will be highlighted.