The purpose of this Diploma Thesis is the construction design of the steam boiler with natural circulation for the combustion of wood biomass according to the specified parameters. It is the boiler with the power of 12 tons per hour of superheated vapor output parameters of 3,3 Mpa at a temperature of 400 °C and a temperature of feed water 105 °C. For the specified parameters I first calculated the stoichiometric calculations, boiler efficiency, and followed by using geometrical parameters of the blocks and thermal calculations set design and the number of heat transfer surfaces, depending on the input parameters of the air and water and output parameters of vapor. The work also includes drawings of the boiler.

This thesis solves a design of a grate boiler burning wood chips or brown coal with a heat output of 160 MW. Stoichiometry flue gas is calculated according to the specified composition of each fuel. The dimensions of the individual heating surfaces are primarily calculated for burning wood chips and subsequently checked for the combustion of brown coal. Design of the boiler is completed by checking the overall heat output. Boiler design is accompanied by drawing documentation.

The thesis deals with the design of the boiler to combustion of mixed communal waste. The introductory chapters present introduction of the problem, short explanation about fuel of the boiler and speciality of the boiler to combustion of mixed communal waste. The main part is the heat calculation of the boiler, which consists of stoichiometry of the combustion, heat losses, then disposition of heat performances to individual exchange surfaces. In the end is summary of calculation and knowledge consequent of the calculation.

The Diploma thesis contains design of plumbing and gas installations in a pension. The theory solves warming of water, ways of warming, and dimensioning according to ČSN 06 0320. The calculation part solves variants of hot water preparations and installations of sewerage water. The practical part contains a design and a projekt of plumbing and gas installations.

The industrial sector in Sweden stands for 38 percent of the total energy use. Within these 38 percent the pulp and paper industry stand for about half of the energy use. Due to the extent of the energy use it is important that we do what we can to keep the energy usage as low as possible within our industries. In this bachelor thesis a case study is performed regarding a problem with a recovery boiler which belong to one of Stora Ensos pulp mills in a small town called Skutskär in Sweden. The problem with the recovery boiler is that it does not reach the temperature of the outgoing steam for which the soda boiler was designed, which causes the efficiency to suffer. The problem with the recovery boiler is not sustainable either in terms of energy use or economy. Recovery boiler 6 (RB6) as it is called is one of two recovery boilers belonging to the pulp mill. Both boilers are designed to produce high pressure steam at 56 bar and 450°C. The high-pressure steam produced goes through a back-pressure turbine where the pressure is lowered to the working pressure of the remaining factory while electricity is produced. Steam at a lower temperature results in lower enthalpy, which in turn will affect the electricity generation in the back-pressure turbine. The purpose of the study is to quantify the loss in electricity generation caused by the lack of steam temperature of RB6. As well as investigating the causes of the lack of heat transfer where the goal is to locate the problem area. A literature study was conducted regarding the efficiency of the recovery boiler, where much emphases was placed on the function of the superheater and the soot system. The superheater accounts for about 30 percent of all heat transfer in a recovery boiler and is directly crucial for reaching the final temperature of the steam. In the literature study, among other things, the design and fouling of superheater is studied to see that if affects the heater transfer. Further, the soot system effect on the heat transfer is also studied and it shows that the soot system has a greatly influence of the final heat transfer. The method used to conduct the study is primarily data analysis. The pulp mills internal analysis program WinMops is used in combined with Excel to analyze operational data. First, the magnitude of the problem was investigated by calculating the effect of RB6’s lack of steam temperature on the total enthalpy of the steam reaching the turbine. Calculations were made for electricity generation in normal cases and under the influence of RB6, where the difference was considered as lost electricity generation. Once the size of the problem was determined, the investigation of causes of heat transfer began, with the superheater coming into focus. The results of the case study show that RB6’s lack of steam temperature causes a loss of electricity production equivalent to 7 million SEK in a normal year and a year with a low electricity price, this amount to 3 million SEK. Whit regard to the second investigation, it is very likely that the superheater causes the temperature drop. However, the study shows that the superheater has no smaller heat transfer surface in relation to the other recovery boiler and that the heat transfer rate is also not deviant. The superheater shows a hint of fouling at the same time as the flow of soot steam is slightly lower on RB6, unlike the mill’s other recovery boiler. An interesting phenomenon that emerges in the study is that the tertiary air flow tends to have a greater effect on RB6 outgoing steam flow than expected. / Industrisektorn står för omkring 38 procent av Sveriges totala energianvändning. Av de 38 procenten står pappers- och massaindustrin för omkring hälften av all energianvändning. Eftersom industrin är en omfattande del gällande energianvändningen är det viktigt att åtgärder utförs för att hålla energianvändningen så låg som möjligt. I detta examensarbete utförs en fallstudie gällande ett problem med en sodapanna som tillhör Stora Ensos massabruk i Skutskär. Problematiken med sodapannan är att den inte når upp i den temperaturen på utgående ångan som sodapannan designades för vilket gör att verkningsgraden blir lidande. Problemet med sodapannan är inte hållbart både sett till energianvändning eller ekonomi. Sodapanna 6 (SP6) som den kallas är en av två sodapannor som tillhör massabruket. Båda sodapannorna är designade för att producera högtrycksånga vid 56 bar och 450°C. Högtrycksångan som produceras går via en mottrycksturbin där trycket sänks till arbetstrycken för resterande fabriken samtidigt som el produceras. Ånga vid lägre temperatur medför lägre entalpi vilket i sin tur kommer att påverka elproduktionen i motrycksturbin. Syftet med studien är att kvantifiera förlusten i elproduktion som den bristande ångtemperaturen av SP6 orsakar. Utöver det är syftet även att utreda orsaker till den bristande värmeöverföringen där målet är att lokalisera problemområdet. En litteraturstudie utfördes gällande effektivitet kring sodapannan varvid mycket tyngd lades på överhettarens samt sotningens funktion. Överhettaren står för omkring 30 procent av all värmeöverföring i en sodapanna och är direkt avgörande för att nå sluttemperaturen på ångan. I litteraturstudien studeras bland annat utformning och försmutsning av överhettaren för att se hur det påverkar värmeöverföringen. Vidare studeras sotningens påverkan på värmeöverföringen och även den påverkar i stor grad den slutgiltiga värmeöverföringen. Metoden som används för att genomföra studien är framförallt dataanalys. Massabrukets interna analyseringsprogram WinMops används tillsammans med Excel för att kunna analysera driftdata. Först utreddes storleken på problemet med hjälp av att beräkna hur stor påverkan SP6 bristande ångtemperatur har på den totala entalpin på ångan som når turbin. Beräkningar utfördes för elproduktion vid normalfall och vid påverkan av SP6 varvid skillnaden betraktades som den förlorade elproduktionen. När problemets storlek var fastställt började utredningen kring orsaker till bristande värmeöverföring varvid överhettaren hamnade i fokus. Studiens resultat visar att SP6 bristande ångtemperatur orsakar en elproduktionsförlust som motsvarar 7 miljoner kronor ett normalår och ett år med lågt elpris rör det sig om 3 miljoner kronor. Gällande den andra utredningen är det med stor sannolikhet överhettaren som orsakar temperaturfallet. Däremot visar studien att överhettaren inte har någon mindre värmeöverförande yta i förhållande till den andra sodapannan samt att värmeöverföringstalet är inte heller avvikande. Överhettaren visar en antydan på försmuttning samtidigt som sotångflödet är något lägre på SP6 till skillnad från brukets andra sodapanna. Intressant fenomen som dyker upp i studien är att tertiärluftflödet tenderar att ha en större påverkan på SP6 utgående ångflöde än förväntat.

[pt] O bambu é rico em biomassa lignocelulósica, e anatomicamente é composto por um sistema de microcanais vasculares alinhados, retos e paralelos entre si. Suas micro e nanoestruturas podem ser modificadas através do tratamento térmico em altas temperaturas (carbonização/pirólise) para obtenção de propriedades elétricas sem a perda da estrutura 3D, possibilitando a aplicação em dispositivos eletroquímicos e microfluídicos eletricamente condutores. As amostras de bambu gigante Dendrocalamus giganteous foram tratadas sob atmosfera de nitrogênio em temperaturas variando de 200 a 1000 graus C e caracterizadas por TGA, ATR-FT-IR, RAMAN, DRX, XPS, HR-TEM, ICP-EOS, (Microtomografia computadorizada de raios-X), I/V, Voltametria cíclica e análise termográfica IR. Foi possível realizar análise estrutural e química; determinação de composições, identificação da transição de fase da estrutura cristalina da celulose para carbono grafítico/turbostrático; medir as condutividades térmica e elétrica. As amostras B-200, B-400 e B-600 apresentaram-se isolantes, enquanto B-700 apresentou-se resistiva (resistividade elétrica)= 1,5 x 10-1 (ohms) m e B-1000 comportamento ôhmico (condutividade elétrica)= 8,4 x 10 2 S m-1 (siemens)/ metro). O dispositivo B-700 foi utilizado como microaquecedor de solventes polares (H2O e etilenoglicol) em regime de fluxo contínuo e chapa de aquecimento, com eficiência de conversão eletrotérmica em fluxo, estabilidade estrutural e reprodutibilidade eletrotérmica. O microaquecedor e a chapa aquecedora alcançaram temperaturas máximas de 340 graus C (0,8 A 6,3V) e 490 graus C (2,0 A, 5,3 V), respectivamente. Isso demonstra que os materiais de bambu pirolisado obtidos nessa pesquisa são promissores para aplicações em supercapacitores, eletrodos, entre outros. / [en] Bamboo is rich in biomass and carbon and, anatomically, is composed of a system of vascular microchannels that are aligned, straight, and parallel to each other. The micro and nanostructures of bamboo can be modified through heat treatment at high temperatures (carbonization/pyrolysis) to obtain electrical properties without losing the 3D structure of the material, which allows the application in electrically conductive electrochemical and microfluidic devices. The present work investigated the influence of heat treatment at high temperatures on the structure and properties of samples of Dendrocalamus giganteous giant bamboo. The samples were subjected to heat treatment under a Nitrogen atmosphere at temperatures ranging from 200 to 1000 degrees C and characterized by TGA, ATR-FT-IR, RAMAN, DRX, XPS, HR-TEM, ICP-EOS, (X-ray computed microtomography), I/V, Cyclic Voltammetry, and IR thermographic analysis. This set of techniques provided structural and chemical information; compositions, the phase transition from cellulose crystal structure to graphic/turbostratic carbon; thermal and electrical conductivity. Samples B-200, B-400, and B-600 showed insulating properties, while B-700 showed resistive behavior (electrical resistivity)= 1.8 x 10-1 (ohms) m and B-1000 showed ohmic behavior (Electric conductivity)= 8.4 x 10 2 S m-1 (siemens)/ meter). The B-700 device was used as a microheater of polar solvents (H2O and ethylene glycol) in a continuous flow regime and heating plate and showed the efficiency of electrothermal conversion in flow mode, structural stability, and electrothermal reproducibility. The microheater and hot plate reached maximum temperatures of 340 degrees C (0.8 A, 6.3 V) and 490 degrees C (2.0 A, 5.3 V), respectively. These results show that the pyrolyzed bamboo materials obtained in this research are promising for applications in supercapacitors, electrodes, heaters, and catalytic microheaters in continuous flow.

No description available.

The military vehicle, Pansarterrängbil 203 (PATGB 203) demonstrates a fault. There are some components in a coolant circuit that fail due to corrosion while others are unaffected. One of the affected components that will be investigated in this report is the water heater. The subject of this technical investigation has been an issue for FMV, Swedish Defence Materiel Administration since a decade. While seeking out the cause of the coolant circuit failing, this investigation aim to analyzing the underlying problems considering material, factors of corrosion and organization. In order to establish the origin of material and appearance of corrosion, experiments were performed. The experiments showed that the original material is an Al-Si alloy. The micrographs indicated varying stratification of the corrosion throughout the unit. The corrosive deposits consisted mainly of oxygen, silicon, aluminum and sodium. Consequently, the protecting passive oxide layer is compromised, which results in a direct connection between the coolant and the underlying material. This direct connection gives rise to the development of corrosion in the material. Clear underlying causes of the corrosion were not found but the most probable suggest on galvanic corrosion accelerated by a stray current. Properly grounding the components decreases the stray current in the system and is essential to avoid corrosion. If grounding the components is not sufficient, additional checks of the coolant with attention to the pH-value and the function of corrosion inhibitors may indicate corrosion at an earlier stage.

According to the U.S. energy consumption survey in 2012, about 25% of the commercial and 42% of the residential building energy were used for heating. Despite the development of new and more efficient Heating, Ventilation, and Air Conditioning (HVAC) systems over the years, the high energy consumption in heating is still one of the major energy efficiency issues. Studies showed that decreasing HVAC operating temperature set points by 4°F will result in energy savings of 15% or more. Thus, the smart localized heating control (SLHC) system was designed and prototyped to provide localized heat directly to a person so that HVAC can run at a lower temperature set point. SLHC detects human movement and delivers the heat based on the result of the target location estimation and temperature measurement feedback. To detect the human movement, image processing techniques were used; image segmentation, mass center detection, background subtraction using the Mixture of Gaussian model, and human feature detection. In SLHC, a near-infrared heater and a tracking function were used to provide an instant and a direct heat to the person in order to minimize wasting energy. The SLHC system is divided into the sensing and processing (SP) and the heating and regulating (HR) subsystem. The SP’s primary function is to process captured video images and measured temperature data. SP also generates and sends the heater operating signal to HR. HR purposes to control the heater’s direction and power based on the signal. The communication between SP and HR was established through Wi-Fi enabled development platform. The SLHC prototype successfully processed the sensing data and transmitted the control signal. The result shows that it detected human movement and estimated the person’s location in 3D space within 10% margin of error. Also, it delivered the focused heat to the surface of the human body and increased the temperature by 10.0°F in 3 minutes at the distance of 1.5m away from the heater. This cost-effective, wireless, and localized heating system demonstrates the potential to improve energy efficiency in buildings. / Electrical and Computer Engineering

Temperature control is a widely researched topic and a common application is in heating systems such as buildings. A temperature control method that is central in ensuring comfort and reduction of energy consumption in modern buildings and other heating systems is based on model predictive control (MPC). Traditionally, the MPC optimal control problem is to track a target, but there are other examples of optimization problems besides tracking problems and one such optimization problem is the economical optimization problem, an optimization based on economical objectives. A heating system with electrical supply may be controlled by an economic MPC such that the economical objective is to consider time-varying prices of electricity.  This thesis studies how time-varying prices of electricity can be utilized as an economical objective in an economical MPC to reduce electricity costs for a double-heater system. This is done using an available model of the double-heater system and an MPC to construct an economical MPC. The performance of the economical MPC is then investigated and compared to the existing MPC.  In the thesis it is found, through a test with six different cost profiles and a test with historical data of forecasts of electricity prices, that the economical MPC can reduce total electricity costs when compared to the existing MPC. Furthermore it is found that the performance of the economic MPC is acceptable when it is compared with and without prediction of setpoint changes, prediction of price changes and an isolating layer between the heaters. The thesis concludes that satisfactory results are attained, as the economical MPC leads to decreased total electricity costs for the double-heater system and notes that the economic MPC is versatile by accepting both user-defined and historical cost profiles.