Evaluation of Guaranteed Performance of Compressors in Operating Conditions

Import 02/11/2016JADLOVEC, M. Hodnocení garantované výkonnosti kompresorů v provozních podmínkách: bakalářská práce. Ostrava : VŠB – Technická univerzita Ostrava, Fakulta strojní, Katedra energetiky, 2016, 54 s. Vedoucí práce: VÝTISK, T. Bakalářská práce se zabývá metodikou hodnocení garantované výkonnosti kompresorů v provozních podmínkách. V úvodu jsou popsány kompresory, jak se stanovuje jejich výkonnost a jakým způsobem se prokazuje. V další části jsou popsány měřidla a zařízení potřebná k stanovení výkonnosti kompresorů. Na základě těchto informací jsou v praktické části spočteny výkonnosti u dvou kompresorů při různých podmínkách. Tyto výkonnosti jsou dále srovnány s garantovanými výkonnostmi výrobce.JADLOVEC, M. Evaluation of Guaranteed Performance of Compressors in Operating Conditions : Bachelor Thesis. Ostrava : VŠB – Technical University of Ostrava, Faculty of Mechanical Engineering, Department of Power Engineering, 2016, 54 p. Thesis head: VÝTISK, T. Master thesis is dealing with methods for Evaluation of Guaranteed Performance of Compressors in Operating Conditions. The introduction describes the compressors, how to specify their performance and how to proof it. In next part can be find gauges and equipment needed to specify performance. On the basis of this information in the practical part are calculated performances for two compressors in different conditions. These performances are compares with guaranteed performance from producer.361 - Katedra energetikyvýborn

Design of a Prototype Device for Study of the Combustion of Fuels in the Fluidized Bed and Reduction of Heavy Metals Emissions

JADLOVEC, M. Návrh prototypového zařízení pro výzkum spalování paliv ve fluidní vrstvě a snižování emisí těžkých kovů. Ostrava: VŠB – Technická univerzita Ostrava, Fakulta strojní, Katedra Energetiky, 2018, 66 s. Vedoucí práce: HONUS, S. Diplomová práce se zabývá návrhem prototypového zařízení pro výzkum spalování paliv ve fluidní vrstvě a snižování emisí těžkých kovů. V úvodu jsou popsány jevy spojené s fluidizací, typy fluidních kotlů, vliv těžkých kovů na organismus a principy čištění spalin od těžkých kovů. Následně je v práci popsán výpočet, návrh a výroba spalovacího zařízení, které je předmětem této práce. Závěrečná část obsahuje poznatky z pilotního testu zařízení a sumarizaci celé práce.JADLOVEC, M. Design of a Prototype Device for Study of the Combustion of Fuels in the Fluidized Bed and Reduction of Heavy Metals Emissions. Ostrava: VŠB – Technical University of Ostrava, Faculty of Mechanical Engineering, Department of Power Engineering, 2018, 66 p. Thesis head: HONUS, S. This diploma thesis is focused on design of a prototype device for study of the combustion of fuels in fluidized bed and reduction of heavy metals emissions. The introduction describes phenomena associated with the fluidized bed, types of fluid boiler, the effect of heavy metals on human organism. After that, the thesis describes the calculation, design and production of the combustion equipment, which is the subject of this work. The final part contains the findings from the pilot test of the equipment and the summary of the whole work.361 - Katedra energetikyvýborn

Techno-economic analysis of fluidized bed combustion of a mixed fuel from sewage and paper mill sludge

The treatment and disposal of sewage sludge is one of the most important and critical issues of wastewater treatment plants. One option for sludge liquidation is the production of fuel in the form of pellets from mixed sewage and paper mill sludge. This study presents the results of the combustion of pelletized fuels, namely sewage and paper mill sludge, and their 2:1 and 4:1 blends in a fluidized bed combustor. The flue gas was analysed after reaching a steady state at bed temperatures of 700-800 degrees C. Commonly used flue gas cleaning is still necessary, especially for SO2; therefore, it is worth mentioning that the addition of paper mill sludge reduced the mercury concentration in the flue gas to limits acceptable in most EU countries. The analysis of ash after combustion showed that magnesium, potassium, calcium, chromium, copper, zinc, arsenic, and lead remained mostly in the ash after combustion, while all cadmium from all fuels used was transferred into the flue gas together with a substantial part of chlorine and mercury. The pellets containing both sewage and paper mill sludge can be used as an environmentally friendly alternative fuel for fluidised bed combustion. The levelized cost of this alternative fuel is at the same current price level as lignite.Web of Science1523art. no. 896

Study of Use of Solid Products from Pyrolysis in Power Engineering

Předkládaná disertační práce se zabývá využitím pevných produktů pyrolýzního procesu, a to jakožto sorbentů zachycujících plynnou rtuť ze spalin fosilních paliv. Využití odpadních produktů je v době energetické krize velmi aktuální téma. V této disertační práci byly propojeny dvě komplexní témata: produkce a vlastnosti pevného produktu pyrolýzy a snižování koncentrací plynné rtuti ve spalinách produkovaných z velkých spalovacích zdrojů na fosilní paliva. Především problematika snižování koncentrací plynné rtuti je v průmyslové praxi vysoce diskutované téma. Z důvodu zavedení nových emisních limitů na úrovní EU mají tato zpřísňující se pravidla nepříjemný finanční a technologický dopad na řadu provozovatelů. Podstatou práce je nabídnout alternativní cestu k výrobě finančně dostupných a dostatečně kvalitních sorbentů, které by bylo možné aplikovat v běžné praxi. Disertační práce byla rozšířena také o výzkum možností využití pevných produktů ze zplyňovacího procesu. Disertační práce je strukturovaná do několika částí, jejichž plynulá návaznost vytváří ucelený postup k naplnění stanovených cílů. První část práce se věnuje teoretickému popisu zplyňovacího a pyrolýzního procesu, systému spalování ve fluidní vrstvě a legislativě v oblasti emisí rtuti s následným popisem produkce rtuti ve spalovacím procesu. Součástí jsou rovněž popisy systému pro stanovení rtuti ve spalinách a technologie pro její eliminaci. Druhá část práce představuje samotnou experimentální a výzkumnou činnost v oblasti zplyňování a pyrolýzy vstupních materiálů. Následuje zhodnocení kvality pevného produktu a jeho následné fyzikální a chemické aktivace. Výzkumná část popisuje také analýzy pro důkladnou charakterizaci sorbentů. Přesně definované sorbenty jsou poté testovány na experimentální trati, která je přímo navázána na fluidní jednotku, v níž jsou spalovány základní paliva. Tyto experimenty probíhají za účelem stanovit adsorpční účinnosti jednotlivých sorbentů, tzn. s jakou účinností dokáží sorbenty snížit koncentraci rtuti ve spalinách. Závěr práce obsahuje interpretaci výsledků, diskuzi a souhrn přínosů pro vědní obor a průmyslovou praxi.The present dissertation deals with the use of solid products of pyrolysis process as sorbents capturing gaseous mercury from fossil fuel exhaust. The use of waste products is a hot topic in times of energy crisis. In this dissertation, two complex topics were combined: the production and properties of the solid product of pyrolysis and the reduction of mercury gas concentrations in flue gases produced from large fossil fuel combustion sources. In particular, the issue of reducing gaseous mercury concentrations is a highly debated topic in industrial practice. Due to the introduction of new emission limits at EU level, these tightening rules are having an unpleasant financial and technological impact on many operators. The essence of this work is to offer an alternative route to the production of affordable and sufficiently high-quality sorbents that could be applied in routine practice. The dissertation has also been extended to investigate the possibilities of using solid products from the gasification process. The dissertation is structured into several parts, the smooth continuity of which creates a coherent procedure to meet the set objectives. The first part of the thesis is devoted to the theoretical description of the gasification and pyrolysis process, the fluidised bed combustion system and the legislation in the field of mercury emissions, followed by a description of mercury production in the combustion process. Also included are descriptions of the system for the determination of mercury in flue gas and the technology for its elimination. The second part of the thesis presents the actual experimental and research activities in the field of gasification and pyrolysis of feedstock materials. This is followed by an assessment of the quality of the solid product and its subsequent physical and chemical activation. The research part also describes the analyses for a thorough characterization of the sorbents. The well-defined sorbents are then tested on an experimental track that is directly linked to the fluidised bed unit in which the base fuels are burned. These experiments are carried out to determine the adsorption efficiency of the individual sorbents, i.e. how efficiently the sorbents can reduce the mercury concentration in the flue gas. The thesis concludes with an interpretation of the results, a discussion and a summary of the contributions to science and industrial practice.361 - Katedra energetikyvyhově

Developing of experimental combustion boiler with stationary fluidized bed and multifuels combustion

Due to the outdated higher requirements for reducing emissions of harmful substances in the combustion of fossil fuels and waste in particular, more and more research is needed, which will lead to the provision of various alternatives to influence the emerging pollutants into the atmosphere. This study deals with the development of experimental combustion units with a stationary fluidized bed with regulated parameters of primary and secondary air supply, performed fuel supply and flue gas parameters. Combustion is carried out in a bubbling stationary fluidized bed with a height of 100 mm and a diameter of 140 mm. The fluidized bed consists of ST 54 glass sand with a mean grain size of 0.22 mm. The basic purpose of the study is to describe the construction of the experimental unit with verification of its functionality. On the experimental equipment was realized experiments in terms of combustion various types of fuels, whether they are fossil fuels (coal), alternative fuels as straw pellets, sludge from wastewater treatment plants, sludge from paper mills or their combinations. Determination of temperature and pressure along the entire length of the unit is a device equipped with thermocouples and pressure sensors

Verification of the analytical design model of a subcritical air ejector and assessment of the behavior of the manufactured machine under different operating conditions

Ejectors are dynamic energy machines that can be designed using analytical methodologies that have been in use for decades. These calculation methods consist of coefficients and equations, which are now untraceable and have not been updated since they were first proposed. Modern literature is devoid of ejector design; therefore, to conduct research on ejectors, it is first necessary to verify the validity of existing computational methods. In this study, we conducted computational fluid dynamics (CFD)-assisted experiments to simulate a subcritical air-to-air ejector with the possibility of controlling the distance of the nozzle mouth from the mixing chamber inlet. It was found that the optimum distance of the nozzle mouth from the mixing chamber inlet (i.e. 7.9 mm) corresponds to the design condition when the ejection coefficient is 1.673 and the secondary medium quantities reach the maximum value of 31.19 kg/h. A change in the position of the nozzle outside the optimum point leads to a deviation in the ejection coefficient and flow rate. The experimental results were compared with those from CFD analysis and the deviation between them did not exceed 2%. Two turbulent flow models, namely k-omega BSL and k-epsilon standard, were used for the comparison.Web of Science4438039802

Pollutants production, energy recovery and environmental impact of sewage sludge co-incineration with biomass pellets

This study describes the production of pollutants, energy recovery and environmental impact of the co-incineration of sewage sludge and biomass pellets. The main objective of this study is to describe the use of energy generated by co-incineration and to assess the environmental impact of emitted pollutants. Co-incineration takes place in five different blended. The combustion takes place in a fluidised bed reactor with an average combustion temperature of 915–939 ◦C. The combustion process is mapped by Fourier transform infrared spectroscopy, Continuous Mercury Monitoring Systems, thermocouples, pressures, and flows sensors. The results show that the concentrations of harmful substances, namely SO2 and NOX, reach values of 12.39–1730.33 mg•m–3 N for SO2 and 93.30–1156 mg•m–3 N for NOX. This means that the emission limits are exceeded 40 times for SO2 and 8 times for NOX in the worst case. Regarding heat recovery, the resulting value of potential energy recovery from the flue gas is 5.35–7.69 MJ•kg–1 , and as the sewage sludge content in the fuel increases, the heat recovery value decreases. The resulting values of pollutant concentrations are also analyzed using a life cycle assessment approach using the GaBi software. The results show that sewage sludge incineration has the greatest impact on climate change, terrestrial ecotoxicity, and human toxicity. Again, as the sewage sludge content in the fuel decreases, the hazardousness of the discharged flue gas decreases. This study presents a relatively promising option to use sewage sludge as a secondary fuel in large combustion sources under certain conditions.Web of Science32art. no. 10340

Softwood and solid recovered fuel gasification residual chars as sorbents for flue gas mercury capture

The scope of this paper is focused on gasification char (GC) utilisation as a direct sorbent for mercury capture from coal combustion flue gas. GC, being a waste material from thermochemical conversion, can represent an economically feasible variation of active coal-based sorbent. The aim of this study is to determine the absorption capacities of GC produced from softwood pellets (SWP) and solid recovered fuel (SRF). The influence of particle size and hot steam activation was examined. The carbon content in produced GC was between 73.7 and 93.4% wt., and SBET parameter up to 737.2 m2middotg-1. The Hg removal efficiency eta Hg was determined by a continuous mercury monitoring system. Promising removal efficiency results were obtained in the case of 0.5-2 mm particle size, hot-steam activated with 76.5 and 62.3% for SWP and SRF GC material, respectively. The results clearly suggest a promising, unconventional approach to waste utilisation in energetics, avoiding its inconvenient disposal. Thus, GC utilisation in the proper way may help to improve the sustainability of the circular economy on both small and big scales and, consequently, have a positive impact on various environmental aspects, such as air pollution control or extraction of resources minimalization.Web of Science29art. no. 10297

Techno-Economic Analysis of Fluidized Bed Combustion of a Mixed Fuel from Sewage and Paper Mill Sludge

The treatment and disposal of sewage sludge is one of the most important and critical issues of wastewater treatment plants. One option for sludge liquidation is the production of fuel in the form of pellets from mixed sewage and paper mill sludge. This study presents the results of the combustion of pelletized fuels, namely sewage and paper mill sludge, and their 2:1 and 4:1 blends in a fluidized bed combustor. The flue gas was analysed after reaching a steady state at bed temperatures of 700–800 °C. Commonly used flue gas cleaning is still necessary, especially for SO2; therefore, it is worth mentioning that the addition of paper mill sludge reduced the mercury concentration in the flue gas to limits acceptable in most EU countries. The analysis of ash after combustion showed that magnesium, potassium, calcium, chromium, copper, zinc, arsenic, and lead remained mostly in the ash after combustion, while all cadmium from all fuels used was transferred into the flue gas together with a substantial part of chlorine and mercury. The pellets containing both sewage and paper mill sludge can be used as an environmentally friendly alternative fuel for fluidised bed combustion. The levelized cost of this alternative fuel is at the same current price level as lignite