FG Maschinen- und Energieanlagentechnik

21 Items

Recent Submissions
Absorption heat transformer - state-of-the-art of industrial applications

Cudok, Falk ; Giannetti, Niccolò ; Ciganda, José L. Corrales ; Aoyama, Jun ; Babu, P. ; Coronas, Alberto ; Fujii, Tatsuo ; Inoue, Naoyuki ; Saito, Kiyoshi ; Yamaguchi, Seiichi ; Ziegler, Felix (2021-02-23)

The use of waste heat or low-exergy heat sources represents a strategic opportunity to reduce the environmental footprint and operation cost of industrial processes. The absorption heat transformer, also known as absorption heat pump type II, is a thermal machine which can boost the temperature of a heat flow by using a negligible amount of electrical power. However, owing to the lack of estab...

A Fully Open Source Remote Laboratory for Practical Learning

Letowski, Bastien ; Lavayssière, Camille ; Larroque, Benoît ; Schröder, Martin ; Luthon, Franck (2020-11-03)

Nowadays, communication and web services are part of our lives, including education, and e-learning applications are used more and more. However, teaching in engineering sciences requires an important amount of practical experiments. Hence, remote laboratories are an attractive solution, offering new tools for both teachers and learners. Our objective is to propose a fully open source remote la...

Improved Solar Operation Control for a Solar Cooling System of an IT Center

Albers, Jan (2020-05-12)

In this contribution, a model predictive control algorithm is developed, which allows an increase of the solar operating hours of a solar cooling system without a negative impact on the auxiliary electricity demand, e.g., for heat rejection in a dry cooler. An improved method of the characteristic equations for single-effect H2O/LiBr absorption chillers is used in combination with a simple dry-...

Einfluss des Lösungsvolumenstroms auf das Betriebsverhalten von Absorptionskälteanlagen

Hunt, Sarah (2020)

Single stage water/LiBr absorption chillers working with tube bundle type heat exchangers are examined with regard to the interaction between thermal and hydraulic behaviour. The inside gained may be transferred to other types of working pairs and types of construction by means of the methods introduce when taking the working conditions into account. This work is structured into a thermal model...

ISHPC 2021 proceedings – online pre-conference 2020

(2020-08)

For decades there has been intense research and development on sorption heat pumping and cooling processes; still, looking at the sales numbers, it is mainly a niche technology. The current transition to an energy system based on renewables changes the boundary conditions. Sorption heat pumps will have an indispensable place in this context, especially for its potential to make use of waste hea...

Steady state meaurements of a 40 kW absorption heat transformer

Corrales Ciganda, José Luis ; Cudok, Falk (2020-08-01)

The repository includes the steady state measurement of a 40 kW absorption heat transformer prototype. The data has been obtained at a laboratory test rig and obtained in the frame of two different research projects for the deveopement of this technology. The measurement equipment description, measurement methodology and resulting systematic uncertainty and standard devition of the obtained val...

Performance of absorption chillers in field tests

Hüls Güido, Walther ; Lanser, Wolfgang ; Petersen, Stefan ; Ziegler, Felix (2018-02-05)

Absorption chillers can use waste heat, solar heat, or excess heat by cogeneration facilities to supply chilled water. Therefore, absorption chillers are important components for poly-generation, which can improve plant utilization and efficiency of the overall energy supply system. Currently, 27 new small and medium-scale (30–160 kW cooling capacity) absorption chillers with high efficiency i...

Erweiterung einer Berechnungsmethode für die Regelung von Absorptionskälteanlagen

Albers, Jan (2019)

Zielstellung für eine erweiterte Methode der charakteristischen Gleichungen ist es, die bisher bekannte Berechnungsmethodik soweit zu verfeinern, dass sie auch für die reale Steuerung und Regelung von einstufigen H2O/LiBr-Absorptionskälteanlagen genutzt werden kann. Dies erfordert eine genauere Beschreibung des Leistungsverhaltens unter verschiedenen praxisrelevanten Randbedingungen (wie z.B. v...

Use Cases with Economics and Simulation for Thermo-Chemical District Networks

Geyer, Philipp ; Delwati, Muhannad ; Buchholz, Martin ; Giampieri, Alessandro ; Smallbone, Andrew ; Roskilly, Anthony P. ; Buchholz, Reiner ; Provost, Mathieu (2018-02-26)

Thermo-chemical networks using absorption and desorption to capture and valorise the potential of very low-grade residual heat (20 °C to 60 °C) to offer a reduction of end user costs and increased primary energy efficiency. The paper demonstrates the technical and economic potential of thermo-chemical networks by defining use cases and their related level of energy efficiency and technological ...

EES simulation model for the part load behaviour of single stage H2O/LiBr absorption chillers

Albers, Jan (2019)

This simulation model (i.e. the main file AKA_CE_Simulation.EES) calculates the partload behaviour of a single stage H2O/LiBr absorption chiller. For the characterisation of the chiller or heat pump only the heat transfer capabilities (i.e. the UA-values) of five heat exchangers (Desorber, Evaporator, Condenser, Absorber and Solution heat exchanger) and the pumped solution flow rate have to be ...

H2OLiBr_GF - Eine EES Bibliothek mit Stofffunktionen und deren partielle Ableitungen für H2O/LiBr Lösungen

Albers, Jan (2019)

The library H2OLiBr_GF.LIB contains a family of property functions (and their derivatives), which are based mainly on the correlations of „Günther Feuerecker, Entropieanalyse für Wärmepumpensysteme: Methoden und Stoffdaten, phd-thesis at Institut für Festkörperphysik und Technische Physik der Technischen Universität München, 1994“. A supplementary description of the numerical implementation in...

H2OLiBr_GF.LIB – Eine EES Bibliothek mit Stofffunktionen und deren partielle Ableitungen für H2O/LiBr-Lösungen

Albers, Jan (2019)

In der Sorptionstechnik sind wässrige Lithiumbromid-Lösungen (H2O/LiBr) ein weit verbreitetes Arbeitsmittel. Für die Berechnung von einzelnen Prozessschritten sowie zur Simulation von ganzen Sorptionskreisläufen (z.B. in Absorptionskälteanlagen, -wärmepumpen und -transformatoren) mit Hilfe von Computerprogrammen werden sowohl kalorische Stofffunktionen als auch Funktionen zum Phasengleichgewich...

Messdaten zum Honigmann-Prozess

Jahnke, Anna (2019-02-01)

Bei den beiliegenden Dateien handelt es sich um Messdaten zu Versuchen zum Honigmann-Prozess. Informationen zur Entstehung der Messwerte und deren Analyse finden sich in der dazugehörigen Dissertation "Untersuchung des Honigmann-Prozesses zur thermochemischen Energiespeicherung"

Untersuchung des Honigmann-Prozesses zur thermochemischen Energiespeicherung

Jahnke, Anna (2019)

Topic of this work is the evaluation of a thermochemical energy conversion and storage process. It can be loaded either with the input of heat or mechanical work. The stored energy can be retrieved in the form of heat, cold or mechanical work at a later point in time. The process was originally invented to drive a fireless locomotive and was patented at the end of the 19th century by Moritz Hon...

Experimentelle und modellgestützte Charakterisierung von Adsorptionswärmeübertragern

Wittstadt, Ursula (2018)

Adsorptionsprozesse können zur Wärme- oder Kälteerzeugung genutzt werden. Dafür kommen thermisch angetriebene Wärmepumpen oder Kältemaschinen zum Einsatz. Zentrale Komponenten dieser Anlagen sind Wärmeübertrager, die mit einem Adsorptionsmaterial befüllt oder beschichtet sind. Da Wärme – und Stofftransport in solchen Adsorptionswärmeübertragern stark gekoppelt sind, ist die gezielte Entwicklung...

Theoretische Untersuchung des Wärme- und Stoffübergangs am laminaren Fallfilm

Mittermaier, Martin (2018)

In this thesis a model is presented describing a laminar film flow over a vertical isothermal plate while heat and mass transfer is occurring. Most common assumptions, such as constant property data and constant film thickness, have been cancelled. The hydrodynamic model results in longitudinal and transversal velocity components and their evolution in the entrance region. Heat and mass transfe...

Dampferzeugeroptimierung zur Abwärmenutzung mittels Dampfkraftprozess an mobilen Verbrennungsmotoren

Stinner, Karl (2018)

Die im Kraftstoff gespeicherte Energie wird auch bei modernsten Verbrennungsmotoren nur zu ungefähr 30% in mechanische Antriebsleistung umgewandelt. Der größere Teil geht als Abwärme an die Umgebung verloren. Der daraus resultierende mittlere Wirkungsgrad des Pkw-Verbrennungsmotors kann jedoch durch teilweise Umwandlung der thermischen Energie erhöht werden. Hierzu kann die im Abgas verbleiben...

Experimental investigation of a liquid desiccant system for air dehumidification working with ionic liquids

Zegenhagen, Mark T. ; Ricart, Cristina ; Meyer, Thomas ; Kühn, Roland ; Ziegler, Felix (2015)

Electrically-driven compression chillers are the commonly used technology for cooling and dehumidifying air. Open sorption systems driven by solar heat are an alternative to conventional air dehumidification technology and may reduce primary energy consumption. For air dehumidification, liquid desiccant systems may exhibit some process engineering and thermodynamic advantages in comparison to s...

Messdaten zur Absorptionskälteanlage FA2

Kühn, Annett (2018-02-09)

This contribution provides measured data of a single stage H2O/LiBr absorption chiller under partload conditions.

Präzisierungen zur Methode der charakteristischen Gleichungen

Albers, Jan (2017-11-24)

The method of characteristic equations tries to describe the part load behaviour of sorption heat converters (e.g. ab- and adsorption chillers, heat pumps and transformers) in a simple but precise manner. Nevertheless, during the application of the established method some disagreements and inaccuracies occur. For example, the analytically determined parameters of the characteristic equation do ...