Institut für Energietechnik

63 Items

Recent Submissions
CE_Method. A MATLAB function for calculating the part load behaviour of absorption chillers and heat pumps based on (C)haracteristic (E)quations

Albers, Jan (2017-09-26)

The algorithm CE_METHOD calculates the part load behaviour of single stage absorption chillers and heat pumps explicitly as function of inlet temperatures and flow rates. For the characterisation of the chiller or heat pump the heat transfer capabilities (i.e. the UA-values) of five heat exchangers (Desorber, Evaporator, Condenser, Absorber and Solution heat exchanger) have to be known.

Assessment of household energy access: the Progress out of Energy Poverty Index (PEPI) toolkit for the microfinance sector

Realpe Carrillo, Natalia (2017)

Sustainable energy for all is one of the explicit goals of the United Nation’s post-2015 development agenda, aiming to overcome the unaffordability, unavailability and unsustainability of energy supply. It refers to the one third of the world’s population that still relies on intermittent or non-existent electricity supply, and on fossil fuels for cooking and heating; and which is mostly locate...

Techno-economic evaluation of a liquid redox process employing amino acid salts for sour natural gas treatment

Sönmez, Hatice Gülsah (2017)

Abundant sour natural gas fields have been left untapped so far due to barriers limiting their economic and environmental viability for power generation. Considering the long-term projections of global energy demand, supply and prices, sour gases could be utilized to supply the regional energy demand of gas producing countries, if there were inexpensive, reliable and environmentally friendly wa...

Thermal design and optimization of heat recovery steam generators and waste heat boilers

Rezaie Navaie, Ali (2017)

Heat recovery steam generators (HRSG) are important and critical equipment of combined cycle power plants (CCPP) that connect the gas turbine system to the steam cycle. The thermal design and the optimization of an HRSG are important for achieving safe operation, higher efficiency and reduced product cost in a combined cycle power plant. This work deals with the comprehensive optimization of the...

An investigation for energy sustainability in cement industries in Tanzania

John, John Pius (2017)

Für Zement-Produktionsprozesse stellen sich einige entscheidende Nachhaltigkeitsfragen, zum Beispiel in Zusammenhang mit ineffizientem Energie- und Rohmaterialeinsatz, Produktversorgung, Produktionskosten sowie sozialen und ökologischen Auswirkungen. Der hohe Energie- und Materialeinsatz bedingt durch Ineffizienzen in Produktionsprozessen von Zement führt wiederum zur Erschöpfung nicht-erneuerb...

Thermodynamic and economic evaluation of existing and prospective processes for liquefaction of natural gas in Malaysia

Bin Omar, Mohd Nazri (2016)

In der Energiewirtschaft wird verflüssigtes Erdgas (LNG) weltweit als umweltfreundlicher Energieträger für Klein- und Großanlagen betrachtet, wobei LNG zur Deckung des stetig wachsenden Bedarfs an elektrischem Strom geeignet ist. In der vorliegenden Arbeit werden sowohl bestehende als auch neue Prozesse zur LNG Produktion thermodynamisch und wirtschaftlich analysiert. Die analysierten Prozesse ...

Methoden und Maßnahmen zur Wirkungsgradverbesserung bei existierenden Energieumwandlungsanlagen

Boche, Lea (2016)

Im Rahmen dieser Dissertation sollen alle in einer Energieumwandlungsanlage auftretenden realen thermodynamischen Verluste erfasst werden und der Anlagenbetrieb soll, wenn möglich, verbessert werden. Schwerpunkt soll dabei die Betriebsoptimierung sein, zusätzlich wird aber auch an einem Beispiel die Umrüstung von bestehenden Kraftwerken mit neuer Technik untersucht. Diese Untersuchungen sollen ...

Operational behaviour and heat transfer in a thermosiphon desorber at sub-atmospheric pressure

Trinh, Quoc Dung (2016)

The application of thermosiphon desorbers or bubble pumps is well known from small capacity absorption refrigerators using ammonia/water as working pair. In the thermosiphon desorber the processes of refrigerant desorption and solution pumping is combined in one hermetical unit. This supersedes the necessity of a mechanical solution pump. In addition, an improved heat transfer is achieved due t...

Partielle Rücklaufkondensation von Reinstoffen und Gemischen in engen, geneigten Kanälen mit rundem und rechteckigem Querschnitt

Klahm, Thorsten (2016)

Bei der partiellen Rückflusskondensation strömt der Dampf in einem geneigten gekühlten Kanal von unten ein und das sich an den Wänden bildende Kondensat fließt ihm entgegen. Diese Art der Gegenstromkondensation bewirkt bei Gemischen eine Trennung der Komponenten. Die geringe Unterkühlung des Kondensats und der geringe Installationsaufwand wirken sich auch bei Reinstoffen positiv aus. Es kann al...

Thermo-economic evaluation, optimization and synthesis of large-scale coal-fired power plants

Wang, Ligang (2016)

A key lever to cope with the well-known issues related to today's extensive use of fossil fuels, e.g., global warming, is to design highly energy-efficient and cost-effective pulverized coal-fired power plants. Future coal-fired power plants will be with high temperature and pressure levels, multiple heat sources, multiple products, and many available technologies integrated to efficiently util...

Analytische Lösung des gekoppelten Wärme- und Stofftransportproblems bei der Absorption im laminaren Rieselfilm

Meyer, Thomas (2016)

Ziel dieser Arbeit ist, die grundlegenden Abhängigkeiten und Einflussparameter auf den gekoppelten Wärme- und Stofftransport in Absorptionswärmewandlern mit Hilfe analytischer Funktionen für technisch möglichst realistische Randbedingungen zu beschreiben. Diese analytische Lösung kann anschließend als Auslegungswerkzeug für die Wärme- und Stoffübertrager für eine möglichst effektive Ausnutzung ...

Synthesis and characterization of novel composite photoelectrodes based on chalcopyrite and silicon for the visible light-driven hydrogen and oxygen evolution

Azarpira, Anahita (2016)

In dieser Arbeit werden effiziente und stabile Mehrschicht-Halbleiter-Elektroden beschrieben, die für die beiden Halbzellenreaktionen der lichtgestützten Wasserspaltung, d.h. die Entwicklung von Wasserstoff (HER) bzw. Sauerstoff (OER), entwickelt wurden. Für die effiziente und stabile Entwicklung von Wasserstoff in sauren Elektrolyten wurden neuartige Photokathoden entwickelt, die hochqualita...

CO2 absorption rate improvement of an amino acid salt solvent with an inorganic promoter

Andrés Kuettel, Diego (2016)

This thesis studies the improvement of the CO2 absorption rate of an amino acid salt solvent with an inorganic promoter. A screening study was carried out to select the most suitable promoter regarding toxicity, absorption enhancement performance and cost. The benefit of the promoted solvent is further quantified in a laboratory mini plant and in a pilot plant that is retrofitted to a coal powe...

Analysis of IGCC-based plants with carbon capture for an efficient and flexible electric power generation

Sorgenfrei, Max (2016)

In this work, systems based on the Integrated gasification combined cycle (IGCC) technology with carbon capture are analyzed regarding an efficient and flexible electric power generation. All analysis are related to a high-efficiency or low-cost IGCC base case with carbon capture which are both commercially available. In the high-efficiency base case, thermodynamic inefficiencies are determined...

Stated preferences based estimation of power interruption costs in private households

Praktiknjo, Aaron J. (2014-04-18)

Concerns regarding supply security are increasingly raised in reaction to the transition of the German energy system toward a renewable and nuclear-free system called “Energiewende”. The goal of this work is to contribute to a measurability of supply security by quantifying the consequences of power interruptions monetarily. The focus lies within the investigation of power interruption costs in...

Density effects of gaseous contaminants in low velocity indoor environments

Sagheby, Seyed Hossein (2016)

The effective design and selection of low velocity ventilation concepts requires detailed knowledge of the contaminant distribution behavior. A simplifying assumption often made in ventilation engineering is that as far as the spreading of gaseous substances is concerned, the bulk air movement and turbulent diffusion are the dominant mechanisms of transport while density differences and molecul...

Modell zur Bestimmung der Ansaugtemperaturen dezentraler Fassadenlüftungsgeräte

Mörtel, Matina (2015)

Das Modell zur Berechnung der Ansaugtemperaturen dezentraler Fassadenlüftungsgeräte ermöglicht die Auslegung der Heiz- und Kühlleistung dezentraler Geräte unter Berücksichtigung der Temperaturerhöhung in der Fassadengrenzschicht. Lüftungsanlagen saugen Außenluft an und konditionieren die Luft entsprechend den gestellten Anforderungen des Aufenthaltsbereichs im Gebäude. Neben den zentralen raum...

Spatially and temporally highly resolved optimization of the Syrian energy supply system

Al Abboud, Nidal (2015)

Syria is a middle income country that faces a serious economic challenge in optimizing its growing energy supply system. Between 2000 and 2010, Syria had an annual population growth rate averaging 2.5% and an annual gross domestic product (GDP) increase of 3.6%. These trends led to an increase in the electricity demand of about 7% per year. Syria must address this challenge in the coming years ...

Fixed-bed biomass pyrolysis: mechanisms and biochar production

Dieguez Alonso, Alba (2015)

The objective of this thesis is to gain a deeper understanding on the slow pyrolytic conversion of biomass in conditions similar to the ones present at industrial scale. The purpose of this is to contribute to two topics of significant relevance in the biomass thermochemical conversion community nowadays. Firstly, the need for further development of more detailed pyrolysis mechanisms, which acc...

A computer program for the exergoeconomic analysis of energy conversion plants

Zhao, Pei (2015)

The exergoeconomic analysis is an important deep-going evaluation method for energy conversion systems. It is a continuation of the energetic and exergetic analysis and a combination of the exergy and economic analysis. In this work, a computer program was developed to facilitate the application of the exergoeconomic analysis to the power plants. The initial data are input to the program, then ...