Strahlwäscher sind durch Ihre Fluiddynamik gekennzeichnet, was eine detaillierte Simulation erschwert. Es konnte gezeigt werden, dass die in der Literatur üblichen empirischen Ansätze aufgrund Ihrer Vereinfachungen den Prozess nur ungenau beschreiben und daher nur für eingeschränkte Bedingungen gelten. Die für die Auslegung von Strahlwäschern relevanten Größen, die erreichbare Pressung und die Stoffaustauschfläche, für beliebige Betriebspunkte wurden in dieser Arbeit durch eine dreidimensionale CFD Simulation berechnet. Es wurden entsprechende Unterprogramme implementiert, um den Stoffübergang im Strahlwäscher zu berechnen. Die chemische Absorption wurde sowohl für die Tropfen als auch für den sich ausbildenden Wandfilm berechnet und als Senke an die Gasphase zurückgegeben. Die Tropfengröße und der Sprühwinkel haben einen essentiellen Einfluss auf die Strömungsverhältnisse im Strahlwäscher. Diese, im wesentlichen von der Düse abhängigen Größen, wurden experimentell mit der Phasen-Doppler-Anemometrie bestimmt. Die Simulationsergebnisse wurden durch Versuche in einer Technikumsanlage verifiziert.

In der vorliegenden Arbeit wird ein Modell zur stationären und dynamischen Simulation einer chemischen Absorptionsgaswäsche zur Abtrennung von CO2 entwickelt und in Matlab implementiert. Die Literaturrecherche zeigt, dass für die Teilmodelle der Kolonnen in diesem Kontext eindimensionale Modelle mit kinetischem Massentransport unter Berücksichtigung des Einflusses der chemischen Reaktionen durch einen Enhancement-Faktor besonders ge- eignet sind. Zusätzlich wird ein rigoroses Modell für die Hydraulik der Kolonnen berücksichtigt. Um auch in zukünftigen Arbeiten flexible Untersuchungen zur Modularisierung chemischer Absorptionsgaswäschen zu ermöglichen, findet ein objektorientierter Programmieransatz auf Basis der Flowsheet-Konzepts Anwendung. Die Validierung der Teilmodelle für Ab- und Desorber erfolgt anhand experimenteller Messdaten aus der Literatur. Die Ergebnisse der Variationsbetrachtungen am Absorberteilmodell stellen eine veränderte Festlegungsmethode der Waschmittelstrommenge bzw. eine alternative Auslegung entsprechender Kolonnen im Kontext der Modularsierung von Gaswäscheprozessen zur Diskussion.:Formelzeichen 5 Indizes 7 Abkürzungen 8 1. Motivation 10 2. Stand der Technik 13 2.1. Einsatzgebiete von Systemen zur Abscheidung von Kohlenstoffdioxid 13 2.1.1. Carbon Capture and Storage (CCS) 13 2.1.2. Aufwertung von Biogas 14 2.2. Aufbau und Wirkungsweise der Absorptionsgaswäsche mit chemischem Anteil 14 2.2.1. Prozessschema einer Absorptionsgaswäsche mit chemischem Anteil 14 2.2.2. Aufbau und Wirkungsweise einer Packungskolonne 15 2.2.3. Aufbau und Wirkungsweise von Waschmitteln 18 2.3. Modellierung von Absorptionsgaswäschen 20 2.3.1. Einteilung der Modelle für chemische Absorptionskolonnen 20 2.3.2. Modelle für die chemische Absorptionskolonne in der Literatur 21 2.3.3. Pilotanlagen und Messdaten 23 2.4. Modularisierung einer Absorptionsgaswäsche 24 2.4.1. Modularisierung verfahrenstechnischer Anlagen - Die 50 %-Idee 24 2.4.2. Modularisierung von Gaswäschern - Analyse der Ergebnisse von Ohle, Obst, Mollekopf und Urbas (2014) 24 2.5. Ableitung der Zielstellung für diese Arbeit 26 3. Modellierung 27 3.1. Allgemeine Grundlagen 27 3.1.1. Bilanzgleichungen und Modellgleichungen 27 3.1.2. Örtliche Diskretisierungsverfahren 28 3.1.3. Zeitliche Diskretisierung 30 3.1.4. Differential-Algebraische Gleichungssysteme 30 3.2. Stoffdatenmodelle 31 3.2.1. Stoffdatenanbindung via CAPE-OPEN 31 3.2.2. Phasengleichgewicht 32 3.2.3. Stoffdatenmodell der Gasphase 35 3.2.4. Stoffdatenmodell der Flüssigphase 35 33.3. Absorptions- und Desorptionskolonne 42 3.3.1. Aufstellen und Diskretisieren der Modellgleichungen 42 3.3.2. Hydraulischer Arbeitsbereich 45 3.3.3. Stofftransport 47 3.3.4. Wärmetransport 50 3.3.5. Zusammenfassung der Annahmen 50 3.4. Wärmeübertrager 51 3.4.1. Reboiler und Kondensator 52 4. Implementierung 54 4.1. Randbedingungen 54 4.2. Implementierung und Arbeitsweise der Simulatorbestandteile 55 4.2.1. PropertyPackages 55 4.2.2. Flows 58 4.2.3. Units 59 4.2.4. FlowSheet 63 4.2.5. Simulator 64 4.2.6. Postprocessor 68 5. Ergebnisse 71 5.1. Stationäre und dynamische Validierung 71 5.1.1. Validierung des Absorbers 72 5.1.2. Validierung des Desorbers 75 5.2. Variation des Absorberdurchmessers 79 6. Zusammenfassung und Ausblick 85 A. Anhang 96 A.1. Ergänzende Angaben zum Stoffdatenmodell 96 A.1.1. Ergänzungen zum Stoffdatenmodell der gasförmigen Phase 96 A.1.2. Ergänzungen zum Stoffdatenmodell der flüssigen Phase 97 A.2. Koeffizienten des hydraulischen Modells nach Billet und Schultes 100 / In this work a model for stationary and dynamic simulation of a chemical gas scrubber is developed and implemented in Matlab. In an extensive literature study the rate-based approach under consideration of an enhancement factor was identified as best fitting choice for the column component models. Additionally a rigoros model accounts for hydraulics in the columns. To allow flexible research in this and future work a object-oriented programming approach based on the flowsheeting concept is used. Absorber and desorber part are validated against experimental data from literature. The modularization of absorber part is investigated in a variation review. The results put up discussion about an alternate determination method for solvent flow and different dimensioning schemes of gas scrubbers in this context.:Formelzeichen 5 Indizes 7 Abkürzungen 8 1. Motivation 10 2. Stand der Technik 13 2.1. Einsatzgebiete von Systemen zur Abscheidung von Kohlenstoffdioxid 13 2.1.1. Carbon Capture and Storage (CCS) 13 2.1.2. Aufwertung von Biogas 14 2.2. Aufbau und Wirkungsweise der Absorptionsgaswäsche mit chemischem Anteil 14 2.2.1. Prozessschema einer Absorptionsgaswäsche mit chemischem Anteil 14 2.2.2. Aufbau und Wirkungsweise einer Packungskolonne 15 2.2.3. Aufbau und Wirkungsweise von Waschmitteln 18 2.3. Modellierung von Absorptionsgaswäschen 20 2.3.1. Einteilung der Modelle für chemische Absorptionskolonnen 20 2.3.2. Modelle für die chemische Absorptionskolonne in der Literatur 21 2.3.3. Pilotanlagen und Messdaten 23 2.4. Modularisierung einer Absorptionsgaswäsche 24 2.4.1. Modularisierung verfahrenstechnischer Anlagen - Die 50 %-Idee 24 2.4.2. Modularisierung von Gaswäschern - Analyse der Ergebnisse von Ohle, Obst, Mollekopf und Urbas (2014) 24 2.5. Ableitung der Zielstellung für diese Arbeit 26 3. Modellierung 27 3.1. Allgemeine Grundlagen 27 3.1.1. Bilanzgleichungen und Modellgleichungen 27 3.1.2. Örtliche Diskretisierungsverfahren 28 3.1.3. Zeitliche Diskretisierung 30 3.1.4. Differential-Algebraische Gleichungssysteme 30 3.2. Stoffdatenmodelle 31 3.2.1. Stoffdatenanbindung via CAPE-OPEN 31 3.2.2. Phasengleichgewicht 32 3.2.3. Stoffdatenmodell der Gasphase 35 3.2.4. Stoffdatenmodell der Flüssigphase 35 33.3. Absorptions- und Desorptionskolonne 42 3.3.1. Aufstellen und Diskretisieren der Modellgleichungen 42 3.3.2. Hydraulischer Arbeitsbereich 45 3.3.3. Stofftransport 47 3.3.4. Wärmetransport 50 3.3.5. Zusammenfassung der Annahmen 50 3.4. Wärmeübertrager 51 3.4.1. Reboiler und Kondensator 52 4. Implementierung 54 4.1. Randbedingungen 54 4.2. Implementierung und Arbeitsweise der Simulatorbestandteile 55 4.2.1. PropertyPackages 55 4.2.2. Flows 58 4.2.3. Units 59 4.2.4. FlowSheet 63 4.2.5. Simulator 64 4.2.6. Postprocessor 68 5. Ergebnisse 71 5.1. Stationäre und dynamische Validierung 71 5.1.1. Validierung des Absorbers 72 5.1.2. Validierung des Desorbers 75 5.2. Variation des Absorberdurchmessers 79 6. Zusammenfassung und Ausblick 85 A. Anhang 96 A.1. Ergänzende Angaben zum Stoffdatenmodell 96 A.1.1. Ergänzungen zum Stoffdatenmodell der gasförmigen Phase 96 A.1.2. Ergänzungen zum Stoffdatenmodell der flüssigen Phase 97 A.2. Koeffizienten des hydraulischen Modells nach Billet und Schultes 100

Strategies to harness the energy from organic waste is gaining importance on a global scale, especially in countries with large quantities of it. In this paper, a techno-economic analysisand a field study were performed to investigate the feasibility of five scenarios for a conceptual biogas facility, based on a case study from Colombia. The plant designs involved anaerobic digestion followed by different combinations of biogas upgrading, combined heat and power and/or steam methane reforming technologies and investigated four different feedstocks. The results demonstrated that the road infrastructure leading to the current proposed site is inadequate, and a new location should be found. Anaerobic digestion alone was most profitable with the shortest payback period. Organic Municipal Solid Waste and Poultry Manure produced high techno-economic potential depending on the scenario. The production of hydrogen using anaerobic digestion, steam methane reforming and combined heat and power with or without upgrading is not recommended due to the current market prices and high heat consumption. However, it can be profitable to implement green energy initiatives as a strategy to establish and lead future energy markets.

Field Programmable Gate Arrays (FPGAs) are being used more frequently in space applications because of their reconfigurability and intensive processing capabilities. FPGAs in environments like space are susceptible to ionizing radiation which can cause Single Event Upsets (SEUs) in the FPGA's configuration memory. These upsets may cause the programmed user design on the FPGA to deviate from its normal behavior. Space missions cannot afford to allow important data processing applications to become corrupted due to these radiation upsets.Configuration scrubbing is an upset mitigation technique that detects and corrects upsets in an FPGA's configuration memory. Configuration scrubbing periodically monitors an FPGA's configuration memory utilizing mechanisms such as Error Correction Codes (ECCs), Cyclic Redundancy Checks (CRCs), a protected golden file, and partial reconfiguration to detect and correct upset memory bits. This work presents improved Xilinx 7-Series configuration scrubbing architectures that achieve minimal hardware footprints, competitive performance metrics, and robust detection and correction capabilities. The two principal scrubbing architectures presented in this work are the readback and hybrid scrubbers which detect and correct Single Bit Upsets (SBUs) and Multi-Bit Upsets (MBUs). Harnessing the performance advantages granted by the 7-Series internal Readback CRC scan, a hybrid scrubber built in software for the Zynq XZC07020 FPGA has been measured to correct SBUs in 8.024 ms, even-numbered MBUs in 13.38 ms, and odd-numbered MBUs in 21.40 ms. It can also perform a full readback scrub of the entire device in under two seconds. These scrubbing architectures were validated in radiation beam tests, where one of the architectures corrected MBUs as large as sixteen bits in a single frame.

This dissertation studies the effects of radiation-induced single-event upsets (SEUs) on field-programmable gate array(FPGA)-based circuits. It analyzes and quantifies a special case in data communication, that is, the synchronization issue of signals when they are sent across clock domains in triple modular redundancy (TMR) circuits with the presence of SEUs. After demonstrating that synchronizing errors cannot be eliminated in such case, this dissertation continues to present novel synchronizer designs that can guarantee reliable synchronization of triplicated signals. Fault injection tests then show that the proposed synchronizers provide between 6 and 10 orders of magnitude longer mean time to failure (MTTF) than unmitigated synchronizers. This dissertation also studies the reliability of block random access memory (BRAM) on FPGAs. By investigating several previous reliability models for single-error correction/double-error detection (SEC/DED) memory with scrubbing, this dissertation proposes two novel MTTF models that are suitable for FPGA applications. The first one considers non-uniform write rates for probabilistic write scrubbing, and the second one combines deterministic scrubbing and probabilistic scrubbing into a single model. The proposed models reveal the impact of memory access patterns on the reliability of BRAMs. Monte Carlo simulations then demonstrate the correctness of the proposed models. At last, the memory access patterns of a type of FPGA application, digital signal processing (DSP) is studied, and mitigation mechanisms for DSP applications are discussed.

No description available.

This thesis is a part of grant assignment and focuses on the effect and properties of input material, limestone, on reactivity and speed of decarbonation. The aim of this thesis is to find the effect of chemical composition, petrography, genesis and diagenesis, porosity and microstructure of limestones on reactivity and speed and profile of decarbonation. The experimental part of thesis describes analysis of chosen limestone samples regarding porosity, reactivity by Bischof-Uhde method and process of decarbonation of calcite in term of crystallinity of product.

This doctoral thesis deals with potentials of methods for cleaning of flue gas from pollutants such as acidic components. Wet method of flue gas cleaning is analysed in detail with special focus on elimination of sulphur dioxide (SO2). Introduction presents advantages and disadvantages of thermal processing of waste and production of undesired pollutants. Following parts comprise facts about main pollutants produced from incineration. Legislation providing for emission of gaseous pollutants from incinerators is also given. Chapter concerning methods of pollutants elimination is mostly focused on absorption (wet and/or semidry scrubber) and adsorption methods. Several up-to-date technological procedures are mentioned; they have a multifunctional effect such as elimination of acidic components, heavy metals, polychlorinated dibenzo-p-dioxines and dibenzo-furanes from flue gas using single injection of suspense. Elimination of mercury (Hg) is among the technologies for heavy metal elimination which is described in detail. Main part of the thesis is related to experiments at two-stage flue gas cleaning equipment. Function of this experimental unit is described along with methods for measurement of individual quantities and detailed description of all the equipment and its components. Experimental measurements carried out at this equipment are explicated and assessed. Along with experimental work, the author has created a simulation model of wet flue gas cleaning in ChemCad programme. Particular operational parameters were tested on this model. This thesis contains results of the measurement which provide background for verification of the mathematical model. Further, the balance of heavy metals conducted on the basis of measurements in waste incinerator is displayed. Main contribution of the thesis may be summed up as follows: ­ Author has designed and constructed experimental equipment for two stage flue gas cleaning. ­ He also formed calculation for pressure drop of O-element prototype equipment and for packing column with FLEXIPAC structured packing. ­ He created data file with measurements at the experimental unit. ­ He determined temperature at outlet of a random device where liquid is injected into stream of hot flue gas. ­ He designed a simulation model which is identical with experimental equipment and which usage enabled comparison of measured and calculated data; it also serves as a basis for industrial applications. ­ Last part deals with creation off heavy metals balance in a case industrial waste incinerator.

Over the past couple of decades Field Programmable Gate Arrays (FPGAs) have become increasingly useful in a variety of domains. This is due to their low cost and flexibility compared to custom ASICs. This increasing interest in FPGAs has driven the need for tools that both qualify and improve the reliability of FPGAs for applications where the reconfigurability of FPGAs makes them vulnerable to radiation upsets such as in aerospace environments. Such tools ideally work with a wide variety of devices, are highly programmable but simple to use, and perform tasks at relatively high speeds. Of the various FPGA configuration interfaces available, the Joint Test Action Group (JTAG) standard for serial communication is the most universally compatible interface due to its use for verifying integrated circuits and testing printed circuit board connectivity. This universality makes it a good interface for tools seeking to access FPGA configuration memory. This thesis introduces a new tool architecture for high-speed, programmable JTAG access to FPGA configuration memory. This tool, called the JTAG Configuration Manager (JCM), is made up of a large C++ software library that runs on an embedded micro-processor coupled with a hardware JTAG controller module implemented in programmable logic. The JCM software library allows for the development of custom JTAG communication of any kind, although this thesis focuses on applications related to FPGA reliability. The JCM hardware controller module allows these software-generated JTAG sequences to be streamed out at very high speeds. Together the software and hardware provide the high-speed and programmability that is important for many JTAG applications.

CubeSat missions needs components that are tolerant against the radiation in space. The hardware components must be reliable, and it must not compromise the functionality on-board during the mission. At the same time, the cost of hardware and its development should not be high. Hence, this thesis discusses the design and development of a CubeSat architecture using a Commercial Off-The- Shelf (COTS) Multi-Processor System on Chip (MPSoC). The architecture employs an affordable Rad-Hard Micro-Controller Unit as a Supervisor for the MPSoC. Also, it uses several radiation mitigation techniques such as the Latch-up protection circuit to protect it against Single-Event Latch-ups (SELs), Readback scrubbing for Non- Volatile Memories (NVMs) such as NOR Flash and Configuration scrubbing for the FPGA present in the MPSoC to protect it against Single-Event Upset (SEU)s, reliable communication using Cyclic Redundancy Check (CRC) and Space packet protocol. Apart from such functionalities, the Supervisor executes tasks such as Watchdog that monitors the liveliness of the applications running in the MPSoC, data logging, performing Over-The-Air Software/Firmware update. The thesis work implements functionalities such as Communication, Readback memory scrubbing, Configuration scrubbing using SEM-IP, Watchdog, and Software/Firmware update. The execution times of the functionalities are presented for the application done in the Supervisor. As for the Configuration scrubbing that was implemented in Programmable Logic (PL)/FPGA, results of area and latency are reported. / CubeSat-uppdrag behöver komponenter som är toleranta mot strålningen i rymden. Maskinvarukomponenterna måste vara pålitliga och funktionaliteten ombord får inte äventyras under uppdraget. Samtidigt bör kostnaden för hårdvara och dess utveckling inte vara hög. Därför diskuterar denna avhandling design och utveckling av en CubeSatarkitektur med hjälp av COTS (eng. Custom-off-The-Shelf) MPSoC (eng. Multi Processor System-on-Chip). Arkitekturen använder en prisvärd strålningshärdad (eng. Rad-Hard) Micro-Controller Unit(MCU) som Övervakare för MPSoC:en och använder också flera tekniker för att begränsa strålningens effekter såsom kretser för att skydda kretsen från s.k. Single Event Latch-Ups (SELs), återläsningsskrubbning för icke-volatila minnen (eng. Non-Volatile Memories) NVMs som NOR Flash och skrubbning av konfigurationsminnet skrubbning för FPGA:er i MPSoC:en för att skydda dem mot Single-Event Upsets (SEUs), och tillhandahålla pålitlig kommunikation mha CRC och Space Packet Protocol. Bortsett från sådana funktioner utför Övervakaren uppgifter som Watchdog för att övervaka att applikationerna som körs i MPSoC:en fortfarande är vid liv, dataloggning, och Over- the-Air-uppdateringar av programvaran/Firmware. Examensarbetet implementerar funktioner såsom kommunikation, återläsningsskrubbning av minnet, konfigurationsminnesskrubbning mha SEM- IP, Watchdog och uppdatering av programvara/firmware. Exekveringstiderna för utförandet av funktionerna presenteras för den applikationen som körs i Övervakaren. När det gäller konfigurationsminnesskrubbningen som implementerats i den programmerbara logiken i FPGA:n, rapporteras area och latens.