LTTT at European Geothermal Congress 2016
Tim Eller, M.Sc. and Dr.-Ing. Florian Heberle in front of the congress building in Strasbourg.

More than 800 participants met on the occasion of the European Geothermal Congress (EGC) in Strasbourg from 9th till 23rd September 2016.The event, which is organized by the European Geothermal Energy Council (EGEC) and takes place every three years, brings together scientists, experts from industry as well as operators of geothermal plants. Currently, there are already 88 geothermal power plants in Europe (installed capacity 2,3 GWel) und 527 district heating networks (4,7 GWth) in operation.

LTTT was represented at the EGC by Dr.-Ing. Florian Heberle and Tim Eller, M.Sc. Florian Heberle presented research results on combined heat and power generation based on the ORC process by giving a lecture entitled “Thermoeconomic evaluation of one- and double-stage ORC for geothermal combined heat and power production”. This presentation and the associated publication are the first international congress contributions of LTTT in the framework of the Geothermie-Allianz Bayern (GAB). This joint project with a cooperation of TU München (Munich School of Engineering), FAU Erlangen and of the University of Bayreuth is planned for a duration of 4 years (2016 – 2019). The kick-off meeting of GAB took place in Munich on 30th September 2016.

Further information on EGC 2016 is available here

New collaboration with EWT Centre of Innovation at Ngee Ann Polytechnic (Singapore)
Mr. Lam, Prof. Dr.-Ing. Brüggemann, Mrs. Tam, Dr.-Ing. Preißinger and Mr. Jin signing the contract.

Prof. Dr.-Ing. Dieter Brüggemann and Dr.-Ing. Markus Preißinger signed an
Expert & Technology Agreement with the Environmental & Water Technology
(EWT) Centre of Innovation at Ngee Ann Polytechnic in Singapore.
The two parties will work together on the Organic Rankine Cycle (ORC)
systems. The director of the centre Mrs. Tam, senior specialist Mr. Lam,
and senior manager Dr. Jin visited the University of Bayreuth and got a
good impression of the broad range of ORC facilities built up in the recent

LTTT/ZET mit Vortrag auf der ICCHMT in Krakau
Raghavendra Rohith Kasibhatla M.Sc. at the ICCHMT conference

From 23rd to 27th May 2016, the International Conference on Computational Heat and Mass Transfer (ICCHMT) was held in Cracow. For the first time this meeting took place in Europe. Under the patronage of the mayor of Cracow, many international simulation experts from science and industry met there to present their research and to discuss latest results.
Raghavendra Rohith Kasibhatla, M.Sc., represented LTTT/ZET at this event. Under the session topic “Two phase and multiphase flows” he gave a lecture on „Numerical Modeling of wetting phenomena during melting of PCM“

„May Photons lighten Brussels“
The SPIE Photonics Europe Conference took place in Brussels from April 2nd to 5th 2016 under very special circumstances. Recovering from the terrorist attacks of March 22nd 2016, the conference participants had to put up with more stringent safety measures and detours due to the continued closure of Brussels airport. Symposium Chair Francis Berghmans pointed out at the beginning of the event that photons may lighten Brussels in these dark times and that terror must not affect science.
For LTTT and BERC, Dr.-Ing. Sebastian Lorenz participated in the conference. Regarding the session “Laser Sources and Application”, he gave a presentation on “Impact of Spatio-Temporal Pulse Profile on the Ignition Process of Passively Q-switched Laser Spark Plugs”.
2016_04_SLO_in Bruessel_groß
Dr.-Ing. Sebastian Lorenz at the SPIE Photonics Europe conference in Brussels .

Thermodynamics Colloquium with ZET/LTTT participation
LTTT participants in Thermodynamics Colloquium 2015 in Bochum (from left to right):
Robert Stäglich, Rohith Kasibhatla, Diana Rauh, Stephan Höhlein, Prof. Brüggemann, Markus Preißinger

The “Thermodynamics Colloquium 2015” was held at the Ruhr University Bochum from 5th to 7th October 2015. The Colloquium is organized by the Technical Committee „Thermodynamics“ of the VDI-Society for Energy and Environment and the ProcessNet-Group „Thermodynamics“. More than 200 scientists had the opportunity to discuss latest research issues in the field of thermodynamics.

In various sessions of this year’s event, LTTT and the Center of Energy Technology (ZET) participated with five contributions. Rohith Kasibhatla, M.Sc. gave a lecture on „Numerical Simulation of Phase Change in macroencapsulated PCM under the influence of an air phase". Dr.-Ing. Markus Preißinger presented the project entitled „High-Throughput-Screening of potential working fluids for thermodynamic cycles on the basis of COSMOtherm and PubChem”. Additionally, several posters were presented: Diana Rauh, M.Sc. " Experimental Investigation of an ORC demonstration plant for waste heat recovery”, Stephan Höhlein, M.Sc. „Experimental Investigation of macroencapsulated phase change materials for the transportation of heat“ and Robert Stäglich, M.Sc. „Thermodynamic Analysis of thermal recyclability of residues from the production of ethanol”.

For more information on the program, please click:

LTTT attends the 9th International Conference on Boiling and Condensation in Boulder, Colorado
Theresa Weith, M.Sc. in front of the "National Center for Atmospheric Research"

The University Memorial Center (UMC) at the University of Colorado in Boulder hosted the 9th International Conference on Boiling and Condensation Heat Transfer between April 26th and 29th 2015.

In front of the impressive backdrop of the Rocky Mountains the participants presented latest results in the research fields of evaporation and condensation, improvement of heat transfer, physical and numerical modelling and experimental studies. Furthermore, forthcoming needs for future research activities were discussed. Theresa Weith, M.Sc. gave a lecture entitled „Flow Boiling of Pure Siloxanes and Their Mixtures in a Horizontal Smooth Tube“.

Not only the presentations met with the participants approval but also the conference dinners at the CU Boulder Football Stadium and at the National Center for Atmospheric Research (NCAR). Both locations provide a beautiful view over CU Boulder and the surrounding mountainsides. The next conference is expected to be scheduled in 2018.

LTTT at the World Geothermal Congress in Melbourne
Dr.-Ing. F. Heberle at the World Geothermal Congress in Melbourne

The World Geothermal Congress (WGC) is hosted in a quinquennial interval. Under the patronage of the International Geothermal Association (IGA) more than 1.500 experts from 75 countries met in Melbourne, Australia, from 20th to 24th April 2015.

The opening address was held by New Zealand’s Energy and Resources Minister Simon Bridges. The congress program included the entire spectrum of geothermal energy supply for all ranges of drilling depths. Experts from science and industry represented current activities in research and developments in the area of reservoir exploration to the point of power plant technology. Acting for ZET/LTTT, Dr.-Ing. Florian Heberle gave a lecture entitled „Thermodynamic Analysis of Double-Stage Organic Rankine Cycles for Low-Enthalpy Sources Based on a Case Study for 5.5 MWe Power Plant Kirchstockach, Germany”. This survey is based on real operating records of the mentioned power plant and compares cutting-edge optimization approaches for this case study.

Besides, the participants at WGC 2015 were offered a variety of excursions and workshops with geothermal background. For more information on WGC 2015 click: here

Download the free Full Paper: Full Paper

1st Swiss ORC Symposium with ZET participation
2014_11_21_Hochschule Luzern_200
University of Lucerne

On Friday, November 21st 2014, the first Swiss ORC Symposium took place at the University of Lucerne. The organizers around Prof. Dr. Ulf Christian Müller welcomed experts from science and industry as well as policy makers, in particular from Switzerland – more than 40 participants attended the symposium.
In preparation of this event ZET/LTTT was asked to present its experiences in the field of ORC and in particular the situation prevailing in Germany. Markus Preißinger gave a lecture especially on thermo-economic aspects of industrial waste heat recovery by means of ORC. In the concluding panel discussion on “ORC – Quo Vadis” Prof. Brüggemann presented the challenges to be solved in order to take profit of the huge opportunities offered by ORC in the future. In particular, specific investment costs are currently still too high for an economical operation of such plants. In this context research and development have to be intensified in coming years.

For more information about ORC Symposium at the University of Lucerne please visit the following link.

ZET/LTTT at the 12th Expert Meeting of Task 42 / Annex 29 of IEA.
Dipl.-Ing. Andreas König-Haagen in front of the largest railway station of the world.

The 12th Expert Meeting of Task 42 / Annex 29 on „Compact Thermal Energy Storage“ took place in Nagoya (Japan) from 8th to 10th October 2014. This year’s meeting was organized by the “Heat Pump and Thermal Storage Technology Center of Japan”. Experts from industry and science from all over the world discussed latest research results on latent and thermochemical storage.

Andreas König-Haagen gave a lecture on the results of the research done by ZET/LTTT within the framework of the development of macro-encapsulated latent storage for heat transport. This research as well as the involvement in the international working group Task 42/Annex 29 are funded by the Federal Ministry for Economic Affairs and Energy.

A highlight of the event was the visit to an ice tank with a capacity of 49 MWh in Nagoya train station. In 2002 the building in the photo shown in the background (see below) was declared the largest train station building in the world and was added to the „Guinness Book of Records“.

For further information and the meeting program click here:

LTTT contribution to ILASS 2014
Prof. Dr.-Ing. Dieter Brüggemann und Dipl.-Phys. Sebastian Lehmann at ILASS 2014.

Prof. Dr.-Ing. Dieter Brüggemann and Dipl.-Phys. Sebastian Lehmann attended the 26th European Conference on Liquid Atomization and Spray Systems in Bremen from 7th to 10th September. At the conference various aspects concerning the topic of atomization and sprays were presented and discussed by experts from industry and science. These aspects included basic behavior of single droplets up to applications in dimensions of marine engines.
Sebastian Lehmann gave a lecture on his current work in the field of “Experimental Analysis and Semicontinuous Simulation of Multicomponent Fuel Droplet Evaporation at Low Temperatures”.

For more information on the conference contac

New DFG project: Pulse train ignition with passively Q-switched laser spark plugs.
Methane flame on the plasma generated by a laser pulse train.

The continuous development of engine combustion processes aims at a further reduction of fuel consumption and emissions. Two concepts pursued by engine developers are leaning and downsizing. Both approaches lead to growing challenges concerning the ignition. The concepts are typically connected with an increase of flow velocities resp. turbulence intensity as well as higher pressure at ignition point. In this context, laser ignition has been considered as a very promising alternative for several years now. However, due to its high demands it hasn’t made its way in practice yet. The use of miniaturized, passively Q-switched laser spark plugs is considered as a promising solution as these systems are smaller, more robust and more cost effective compared to actively Q-switched laser spark plugs. In addition, these laser spark plugs are able to generate pulse trains that lead to an advantageous distribution of ignition energy.
The German Research Foundation (DFG) is now supporting research on the effect of a pulse train laser ignition on the ignition process (energy input, flame kernel formation and propagation of the flame). Based on this, the ignition parameters are to be optimized under increased flow velocities and increased densities.
The research conducted within the framework of the Bayreuth Engine Research Center (BERC) is designed in its first phase for a period of three years.

More information on the project can be found here and in the press release of the University Bayreuth.

Energy Technology Excursion on 11th/12th June 2014

35 students were accompanied this year’s energy technology excursion.

This year’s energy technology excursion headed for Southern Bavaria. 35 students were accompanied by the excursion organizer Dipl.-Phys. Sebastian Lorenz and by Dipl.-Ing. Christian Zöllner.

First stop of the two-day trip was the company N-ERGIE in Nuremberg. After an informative lecture, the combined cycle power plant was visited as well as the construction site of a large heat storage system, which is scheduled to start operation in 2015. The steel tower of the heat storage located on the power plant site in Nuremberg-Sandreuth has grown bigger and bigger in recent months and has now reached almost all of its final height of around 70 meters. According to N-ERGY, the storage tank is a visible sign of the phase of energy transition in the region and takes over a pioneering task in Germany.

The next stage of the trip was information center “Walchenseekraftwerk” in Kochel am See. At first, the spokesman of E.ON Wasserkraft (hydropower) gave a lecture on the local hydroelectric plant. Then the participants went on a guided tour by cable car up to the surge tank which is about 200 m above the lake Kochelsee (see photo). The guided tour ended with a visit of the turbine hall and the information center.

The turbine hall.

On the second day a visit of Munich airport was scheduled. After the obligatory security check, the participants had the opportunity to get to know the various areas of the airport while looking behind the scenes. The interesting tour ended at the supply center. There, Dipl.-Ing. Steffi Nikol – former graduate in environmental and bioengineering sciences at Bayreuth University and current employee at the power center of the airport – and three colleagues of her welcomed the participants of the excursion. Divided into two groups, the participants were shown the hot water and energy supply of the airport. The service area is currently under construction as capacity expansions are necessary with respect to the completion of the new terminal.

The steel tower of the heat storage.

The last stop of the extensive excursion was the electric power transformation substation of TenneT in Schwandorf. After a lecture and a subsequent guided tour, the participants went on their way home with lots of impressions gained during the trip.

The participants of the energy technology excursion 2014 would like to thank all companies visited for their hospitality as well as the interesting lectures and guided tours.

LTTT/ZET participate in ASME ORC 2013
Following up the success of the first Organic Rankine Cycle (ORC) event in 2011, the "2nd International Seminar on ORC Power Systems" took place in ‚Rotterdam, NL from 7th till 9th October. This event is organized by the ASME (American Society of Mechanical Engineers) International Gas Turbine Institute.

More than 400 international ORC experts from industry and research discussed latest research results and new developments. LTTT and the Centre of Energy Technology (ZET) participated with several contributions. Dr.-Ing. Florian Heberle gave a lecture on "Experimental investigations of heat transfer characteristics and thermal stability of siloxanes", Dr.-Ing. Piotr Klonowicz reported on "2D unsteady RANS simulations of an organic vapor partial admission turbine". Furthermore, Theresa Weith, M.Sc. and Dipl.-Ing. Markus Preißinger presented research results on posters.

In addition to the main event, the first official meeting of the ORC Power Systems Committee in IGTI ORC took place under the auspices of ASME. From now on, Prof. Dr.-Ing. Dieter Brüggemann will be responsible member for the topic "experiments and prototypes".

More information and the program of events is available at

Lecture at the congress “Biogas in Agriculture - Status and Prospects”

For the third time the Kuratorium für Technik und Bauwesen in der Landwirtschaft e.V. (KTBL) (Association for Technology and Structures in Agriculture) and the Fachagentur Nachwachsende Rohstoffe e.V. (FNR) arranged a common biogas congress. In Kassel experts presented current progress in biogas technology concerning the topic “biogas in agriculture” on 10th and 11th September.

The fact that more than 190 people took part in the congress shows that the latest developments for the optimization of biogas production and marketing are of great interest. In the framework of the forum “Entwicklungen der BHKW-Technologie” (Developments of CHP Technology) Dipl.-Ing. Markus Preißinger presented findings of LTTT in his lecture “Abwärmenutzung von Biogas-BHKWs mittels Nachverstromung in ORC-Anlagen” (Waste Heat from Biogas CHPs using Heat Recovery for Power Production in ORC Systems”.


For more information about the Congress, please contact:

LTTT participates in 11th ICE 2013 of SAENA
Dipl.-Ing. Wolfgang Mühlbauer and
Prof. Dr.-Ing. Dieter Brüggemann

The International Conference on Engines & Vehicles (ICE) has been organized by SAENA (Society of Automotive Engineers Italian Section) since 1990. SAENA thus promotes the exchange of scientific and practical knowledge in the field of vehicles and engines.

More than 200 participants from all over the world met during the 11th ICE 2013 on Capri, Napoli (Italy) from 16th to 19th September 2013.
Dipl.-Ing. Wolfgang Mühlbauer and Prof. Dr.-Ing. Dieter Brüggemann represented LTTT and BERC at the conference. Within the session “Particle Emission” Wolfgang Mühlbauer presented his lecture “Optical Studies about the Influence of Diesel Engine Operating Parameters on the Physicochemical Properties of Emitted Soot Particles”.
This paper was published in SAE International Journal of Engines (6(3):1866-1876,2013,doi:10.4271/2013-24-0184,

For more information on ICE2013 please visit the following link:

LTTT contributes to the 17th ETH Conference

The 17th ETH Conference on Combustion Generated Nanoparticles took place in Zurich from 23rd to 26th June 2013. The European Union declared 2013 as the “Year of the Air”. Thus, this year’s ETH Conference focused on the question “How to Regulate Ambient Nanoparticles”.
More than 350 participants attended various sessions (fundamentals, combustion engine emissions, ambient particles and health effects) and discussed latest findings.
LTTT contributed to the session “combustion engine emissions” by a poster entitled “Influence of engine parameters on physical properties of emitted diesel soot particles”. This poster was created by Dipl.-Ing. Wolfgang Mühlbauer.

More information on ETH Conference is available here

LTTT contribution to ExHFt8
: Auditorium of the Instituto Superior Técnico in Lisbon

More than 350 scientists and experts met on the occasion of the 8th World Conferences on Experimental Heat Transfer, Fluid Mechanics and Thermodynamics (ExHFT8) in Lisbon from 16th till 20th June 2013 in order to discuss progress achieved in the areas of heat transfer, fluid dynamics, multiphase flows, optical measurement methods and thermodynamics and to exchange latest findings.
In a poster contribution Dr.-Ing. Florian Heberle presented measurements of heat transfer during evaporation of pure fluorinated hydrocarbons (R245fa, R365mfc) and their mixtures in horizontal, electrically heated tubes.

ORC session at EMC 2013
Invited by Prof. Hans Jacobi, President of the Society of Metallurgists and Miners (GDMB), Prof. Dieter Brüggemann participated in the European Metallurgical Conference (EMC) 2013 in Weimar and took over the chairmanship in the session “Waste heat recovery by ORC power generation”.
The list of speakers included Prof. Mario Gaia (Turboden s.r.l.) and Dipl.-Ing. (FH) Scholz- Stahlhofen (IGATEC GmbH). Dr.-Ing. Florian Heberle from LTTT showed in his presentation „Organic Rankine Cycle: an alternative to water steam cycles for efficient waste heat recovery“ the differences and benefits of ORC compared to conventional steam processes. The well-attended session revealed that power generation from waste heat is of great interest especially related to energy-intensive production processes.

7th VDI Conference on Biogas
On 12th and 13th June 2013 the 7th VDI conference “Biogas 2013 energy source of the future” took place in Nürtingen. Experts from research and industry discussed technical aspects of biogas production and utilization.

Theresa Weith, M.Sc. from LTTT delivered a speech on “electricity from waste heat of biogas block heat and power plants”. In the first instance she outlined options of using waste heat in thermal storage systems and for additional power generation. Then, she discussed thermodynamic boundary conditions for biogas power and heat cogeneration and drew a comparison of the conventional steam process and the organic rankine cycle (ORC).

More information on VDI conference on biogas available here.

LTTT contribution to the European Geothermal Congress 2013 in Pisa
Dr.-Ing. F. Heberle at the European Geothermal Congress in Pisa.

Geothermal power generation can look back on a particularly long history in the Italian province of Pisa. In 1904 the world’s first geothermal heating plant was built in the small town of Larderello, since 1913 there has been power generation. In view of this centennial, the European Geothermal Congress (EGC) 2013 took place in Pisa from 3rd to 7th June 2013, organized by the European Geothermal Energy Council (EGEC).

More than 500 participants from Europe and from Africa took the opportunity to discuss latest research results and new developments in the areas of reservoir development, near-surface geothermal energy as well as power generation from deep geothermal energy.

Dr.-Ing. F. Heberle gave a lecture on „Thermoeconomic comparison of designs for geothermal combined heat and power generation”. In this context he discussed the thermo-economic evaluation of parallel circuit alternatives and hybrid power plants.

For more information on EGC 2013 and EGEC click here:

ZET / LTTT auf dem neunten Expert Meeting des Task 42 / Annex 29
The picture shows the participants of the ninth Expert Meeting of Task 42 / Annex 29.

The ninth Expert Meeting of Task 42 / Annex 29 on “Compact Thermal Energy Storage Material Development and System Integration” took place in Freiburg from 15th to 17th April 2013. This year’s meeting was organized by the Fraunhofer Institute for Solar Energy Systems (ISE).

The Center of Energy Technology (ZET) was represented by Dipl.-Ing. Fabian Rösler and Dipl.-Ing. Andreas Haagen from LTTT. Andreas Haagen presented current research on numerical simulation of latent thermal storage. He reported on the approach of establishing correlations through detailed mesoscale model calculations and to integrate them into system simulations.

On the occasion of the meeting it was also announced that Task 42 / Annex 29 has been extended until the end of 2015 with SHC (Solar Heating and Cooling) and ECES (Energy Conservation through Energy Storage) of the International Energy Agency (IEA). The Center of Energy Technology and LTTT will also continue to contribute to these ongoing activities.

Further information on the Expert Meeting 2013 is available here (

LTTT lecture at annual meeting of DECHEMA and VDI
LTTT bei Dechema und VDI
Anja Plasse during the exhibition

The annual meeting of the sections Fluid Process Engineering and Heat and Mass Transfer organized by DECHEMA and VDI took place at the Kongresshaus Baden-Baden from 20th to 21st March 2013.

Dipl.-Ing. Anja Plasse from LTTT gave a lecture entitled “Numerical simulations and experiments for loading and unloading of latent thermal storages”. A double pipe latent heat storage was investigated within the framework of this research. Two different simulation models have been presented (a detailed model and a simplified one) and the simulation results have been compared to results of measurement.

For further information on the program of the annual meeting click here.


Final assessment of FORETA


The Bavarian Research Cooperation FORETA examined examples of applications developed for the efficient supply, usage and storage of energy in small and medium enterprises (SMEs). In this context, LTTT elaborated in cooperation with Glen Dimplex Germany subproject H (entitled “Increasing the Efficiency of Air/Water Heat Pumps by integration of latent heat storage systems”.)

On 6th March the research group FORETA was assessed by a panel of well-known professors from all over Germany. The contribution of LTTT and its industrial partner was emphasized as one of the best subprojects.

For more information on FORETA contact


LTTT at International Conference on engine combustion
LTTT bei Internationaler Tagung zu Motorischer Verbrennung
Sebastian Lorenz giving his lecture

The 11th international conference “Engine Combustion” organized by the Haus der Technik took place in Ludwigsburg from 14th to 15th March 2013.

LTTT contributed with two lectures.

Sebastian Lorenz gave a lecture on the topic of “Flow field analysis of injection and combustion with the Optical Flow method”.
Wolfgang Mühlbauer presented a poster entitled “Optical analysis of combustion behavior and soot emissions of biodiesel / diesel mixtures at different performances with EGR”.


Biogas Training Seminar at Kloster Banz

The regular Biogas Training Seminar took place at Kloster Banz near Bad Staffelstein on 7th February 2013. Information on the latest guidelines, safety requirements and developments was provided for about 160 participants.

Fabian Rösler from LTTT gave a lecture on the use of mobile thermal storage for waste heat recovery together with Mr Froese, LaTherm GmbH and Mr Wunderlich, Office for Food, Agriculture and Forestry Münchberg.

Documents are available for download at the following link:

Final conference FORGLAS
Dipl.-Ing. Bernd Gassenfeit presents together with his industrial partner Nachtmann (represented by Dipl.-Ing G. Mader) the results of the FORGLAS-projects.

The project FORGLAS was successfully completed in the framework of a conference at the Nuremberg Academy on 16th and 17th January 2013.

Final results of the ten FORGLAS subprojects were presented and discussed in which three Bavarian research institutions (Fraunhofer ISC, University of Bayreuth, University of Erlangen-Nuremberg) and 13 partners from industry have cooperated for three years in the field of multifunctional glass materials for energy-efficient buildings. A very positive conclusion could be drawn.

LTTT was involved in the research with two cross-sectional themes.

In sub-project “Modeling and simulation of the temperature profile of glass facades”, the developed solutions for innovative, highly energy-efficient components were analyzed with computerized simulations.

In sub-project “Spectroscopic in-situ diagnostics in the functionalization of glass” laser spectroscopic measurement methods for a rapid control of the coating quality in CVD processes were adapted and tested under realistic conditions.

Florian Heberle received a PhD

Dipl.-Ing. Florian Heberle has been working at the Department of Engineering Thermodynamics and Transport Processes (LTTT) since 2007 under the direction of Professor Brüggemann. During this time he wrote his doctoral thesis entitled “Analysis of zeotropic fluid mixtures in Organic Rankine Cycle for geothermal power generation”.
In his thesis he developed an approach to improve the efficiency of geothermal power plants. His Ph.D. exam took place on 21st December 2012. Dr.-Ing. Heberle will continue his energy research activities in the future as Akademischer Rat (Academic Council) at LTTT and the Center of Energy Technology founded in 2012.

Florian Heberle (center) with his examiners Professors Spliethoff (TU München), Brüggemann, Jess and Glatzel (from left)

High temperature heat pump Temperature increase of industrial waste heat to above 100°C
Recent research shows a significant potential for the use of industrial waste heat especially in the temperature range from 40°C to 60°C. Due to the use of high-temperature heat pumps, temperatures ranging from 100°C to 120°C can be provided.

A variety of potential working fluids allows an adaptation of the process to the changing conditions in comparison to the provided heat or hot water up to 70°C.

In the context of process simulation, the examination of a total of 35 potential working fluids shows that the thermodynamically efficient fluids lead to a coefficient of performance larger than 3 thus indicating that they are energetically viable.

Based on the simulation results, the project partners (ATEV/LTTT and Mayer Elektrotechnik are starting the second phase of the project where a test bench with a high temperature heat pump is built. With the help of the test stand, the behavior of the heat pump is evaluated in practice and the simulations are validated.

More information on high temperature heat pumps and temperature increase of industrial exhaust heat over 100°C can be found here.

Publication on greenhouse gas emissions in geothermal power generation

The Organic Rankine Cycle (ORC) is one of the few cycles which is suitable for power generation at low temperature levels. The choice of working fluids as a function of the thermal water temperature is a significant potential for the improvement of the ORC. Due to the use of hydrofluorocarbons, the number of potential materials and thus the potential increase in performance grows.
The increase in efficiency is associated with additional emissions due to leakage during operation, filling and disposal. Potential greenhouse gas emissions from geothermal power plants were calculated in a short report commissioned by the Umweltbundesamt (Federal Environment Agency) through the Centre of Energy Technology (University of Bayreuth) for different scenarios depending on the emission rate and the stage of development of geothermal power generation.

This report is now available for free download at

Storage technologies for future energy supplies
IRES 2012_Foto_200
From left: A. Hagen, F. Rösler, A. Plasse
Today’s storage technologies are tomorrow’s energy supplies. On the 7th International Conference and Exhibition on Renewable Energy Storage (IRES 2012), Berlin, some 600 national and international industry leaders, scientists and politicians discussed the various aspects of energy storage technologies. In his introduction, Bundesumweltminister (Federal Environment Minister) Peter Altmeier outlined the importance of storing renewable energy for the future supply market.

Dipl.-Ing. Fabian Rösler presented in the framework of a subsequent scientific session on thermal storage his latest model on the simulation of latent thermal storage taking close contact melting in storage capsules into consideration. At the poster exhibition, LTTT was represented by two Posters.

Dipl.-Ing. Anja Plasse presented the results of experimental and numerical investigations of a double-tube latent heat storage and Dipl.-Ing. Andreas Haagen presented results concerning the application of latent thermal storage in heating systems with air/water heat pumps.

During the conference, the good contributions of LTTT were officially recognized. Among the approximately 70 posters, Ms Plasse’s poster won the second place in the poster award, the entire storage group being involved.

For further information, contact:


LTTT on Geothermal Congress 2012
In the framework of the Geothermal Congress 2012, about 250 experts from industry and research met in Karlsruhe from 13th to 16th November to discuss current topics in the field of near-surface and deep geothermal energy.
Dipl.-Ing. Florian Heberle presented results for the thermo-economic analysis of geothermal hybrid power plants for combined heat and power generation. The interesting lecture program was completed by a visit to the geothermal power plants of Landau and Insheim.

The picture shows the power plant of Landau

LTTT at eighth expert meeting of Task 42 / Annex 24
Dipl.-Ing. Fabian Rösler is second from the right in the second row from the bottom.

From 17th to 19th October, the eighth Expert Meeting of Task 42 / Annex 24 (4224) on the topic of “Compact Thermal Energy Storage Material Development and System Integration” took place in Petten (Netherlands).
The Expert Meeting of the Implementation Agreement SHC (Solar Heating and Cooling) and ECES (Energy Conservation through Energy Storage) of the International Energy Agency (IEA) was organized by the Energy Research Centre Netherlands (ECN). In their working groups about 50 experts coming from over 20 countries discussed the steps necessary for the development and implementation of thermal storages.
Fabian Rösler (LTTT) was invited to give a presentation on the numerical simulation of latent thermal storages, taking close contact melting in storage capsules into consideration. In the future, LTTT will contribute to the working groups “Numerical Models” as well as “Test and Characterization” the Task being extended for another three years.

For further information contact:

LTTT and ZET participate in thermodynamics colloquium 2012 in Potsdam
From left: F. Heberle, W. Mühlbauer, Prof. D. Brüggemann, S. Lorenz, M. Preißinger

From October 8th to 10th, the annual “Thermodynamics Colloquium” held in conjunction with the 26th European Symposium on Applied Thermodynamics (ESAT) took place in Potsdam. By combining the two events, more than 270 scientists had the opportunity to discuss the latest research in the field of thermodynamics.

LTTT and the Centre of Energy Technology (ZET) contributed in several ways. Dipl.-Ing. Florian Heberle’s presentation on “Second law analysis of Organic Rankine Cycles with zeotropic fluid mixtures for geothermal power generation” was of great interest.

Dipl.-Ing. Markus Preißinger presented his research findings in the field of “Organic Rankine Cycle”, Dipl.-Phys. Sebastian Lorenz in the area of optical measurement techniques and Dipl.-Ing. Wolfgang Mühlbauer in the field of engine research.

For further information and the program, contact


LTTT/Zet lectures in September

The Centre of Energy Technology represented by the Department of Engineering Thermodynamics and Transport Processes took part in several conferences giving lectures on different topics.

Dipl.-Ing. Markus Preißinger was invited to give the keynote-lecture on Organic Rankine Cycle at the “Heat Powered Cycles Conference 2012” in Alkmaar. His presentation was about “Supercritical Organic Rankine Cycle for geothermal application” More information is available on the homepage of HPC as well as in the program guide.

Dipl.-Ing. Florian Heberle was personally invited to give a speech at the “International Symposium on Advanced Waste Heat Valorisation Technologies” and reported on the current research activities of ZET in the field of Organic Rankine ‘Cycles in a lecture called “Advanced ORC fluid research for cycle efficiency improvement”. The program is available here.

Within the framework of the KUMAS forum “Job and Education”, Dipl.-Ing. Markus Preißinger gave a lecture titled “from A-levels to Dr.-Ing. – energy technology in Bayreuth” in which he first and foremost mentioned the cooperation between universities and colleges within the Technologie-Allianz Oberfranken. Further information will be available in a separate news report.

LTTT’s contribution on the occasion of ICLASS 2012 taking place in Heidelberg
Figure: Dipl.-Phys. Sebastian Lorenz in Heidelberg

From September 2nd to 6th, the twelfth ICLASS (International Congress on Liquid Atomization and Spray Systems) took place in Heidelberg. LTTT was represented by Dipl.-Phys. Sebastian Lorenz presenting his research on “Spray Velocity Field Analysis with Optical Flow Method – An Alternative to Particle Image Velocimetry”. This contribution was presented and discussed within the session “Drop Diagnostics”.

HEFAT2012 – 9th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics
Prof. Dr.-Ing. Dieter Brüggemann and Theresa Weith, M.Sc., at the conference hotel of HEFAT2012

In the course of HEFAT2012, scientists from all over the world met on Malta from 16th to 18th of July 2012 in order to present their latest research activities in the field of heat transfer, fluid mechanics and thermodynamics.

Representative for the Center of Energy Technology (ZET), Theresa Weith, M.Sc., and Prof. Dr.-Ing. Dieter Brüggemann of the department of Engineering Thermodynamics and Transport Processes (LTTT) attended the conference. Ms. Weith presented research results in the field of the absorption refrigeration technology. Her talk “Multi Effect Plants and Ionic Liquids for Improved Absorption Chillers“ attracted wide interest.


Lecture and poster presentation at the ETH-Conference on Combustion Generated Nanoparticles
From left: Ulrich Leidenberger, Wolfgang Mühlbauer

More than 300 scientists met in Zürich from 24th to 27th June 2012 at the occasion of the 16th ETH Conference on Combustion Generated Nanoparticles.
Wolfgang Mühlbauer and Ulrich Leidenberger from LTTT presented in a lecture current results of optical analysis concerning the influence of diesel engine operating parameters on the physical and chemical properties of emitted soot.
In addition, a poster presented a study of particles emitted by a direct injection gasoline engine in steady state and transient operation.

LTTT with contribution at ECOS 2012
Dipl.-Ing. Markus Preißinger

Dipl.-Ing. Markus Preißinger represented the department of Engineering Thermodynamics and Transport Processes (LTTT) and the Centre of Energy Technology (ZET) at the "International Conference on Energy, Cost, Optimization and Simulation (ECOS)" from June 26th to 29th in Perugia, Italy.
Mr. Preißinger presented his research on the "Exergetic analysis of biomass fired double-stage Organic Rankine Cycle". The presentation was discussed within the session "Organic Rankine Cycles".


The 12th International Conference on Energy Storage (Innostock 2012)
Dipl.-Ing. Fabian Rösler

Under the auspices of the International Energy Agency (IEA) and its implementing agreement Energy Conservation through Energy Storage (ECES) the 12th International Conference on Energy Storage (Innostock 2012) took place in Lleida (Spain) from 16th to 18th May 2012.
Around 320 scientists from 39 countries presented and discussed latest developments in the field of underground storage, latent and sensible heat storage as well as chemical and electrical storage. In this context, Dipl.-Ing. Fabian Rösler presented the implementation and preliminary applications of a model for numerical simulation of macro-encapsulated latent heat storage systems.


CARNOT Usergroup meeting 2012 took place at LTTT

This year’s CARNOT Usergroup meeting took place at LTTT in Bayreuth on 13th and 14th February. Around 30 participants coming from France, Austria, Greece, Switzerland and Germany discussed further developments and current activities applying CARNOT Blockset for Matlab Simulink.

Energy engineering excursions summer term 2012

This year’s excursion in energy engineering will take place during the Whitsun weekend from 29th May till 1st June. This year two destinations are offered (each for about 33 persons) due to the great demand. You can take part in either of them if places are available..

Program of excursions for download.

FORGLAS - LTTT report on second colloquium
From left to right: B. Gassenfeit, Prof. Brüggemann and S. Lehmann

Since 2009 the research network FORGLAS has been operating under the umbrella of the Bavarian Research Group BayFOR in the field of multi-functional glass materials for energy-efficient building technologies. Three research centers are cooperating with 13 industrial partners within ten partial projects.
The second interim assessment took place at the historical monastery of Bronnbach on 15th December 2011. LTTT is committed with two projects. The functionalization of glass is examined by Dipl.-Ing. Sebastian Lehmann applying spectroscopic in-situ diagnostics, Dipl.-Ing. Bernd Gassenfeit deals with the modeling and simulation of the temperature profile of glass facades and roofs.


New Employees at LTTT
2012_01 Neue Mitarbeiter
From right to left: A. Plasse, D. Peters and S. Pöllinger

Three further employees have recently been added to the staff of LTTT.
Anja Plasse is engaged in the use of latent thermal storage. All kinds of research in the field of Organic Rankine Cycle are carried out and supported by M.Sc. David Peters. Dipl.-Ing. Simon Pöllinger is engaged in the field of absorption refrigeration by means of ionic liquids. Thus the field of energy engineering of the Department as well as the Zentrum für Energietechnik (ZET) (=Centre for Energy Technology) have been expanded.

Professor Brüggemann elected to the board of WATT

The Organic Rankine Cycle (ORC) provides the interesting opportunity of getting thermal power even more profitably if its quantity and temperature are not sufficient for a conventional water-steam power plant process. The growing importance of this technology has led to the fact that the ORC trade association was founded as a registered association with headquarters in Essen. As LTTT has been engaged in the field of ORC, especially in research and development, for several years, its Head of Department, Professor Brüggemann has been elected to the board consisting of 6 members.

ORC trade association founded

The Organic Rankine Cycle (ORC) provides the interesting opportunity of getting thermal power even more profitably if its quantity and temperature are not sufficient for a conventional water-steam power plant process. The growing importance of this technology has led to the fact that the ORC trade association was founded as a registered association with headquarters in Essen. As LTTT has been engaged in the field of ORC, especially in research and development, for several years, its Head of Department, Professor Brüggemann has been elected to the board consisting of 6 members.

LTTT at the 6th International Renewable Energy Storage Conference (IRES 2011)
IRES 2011
F. Rösler during his presentation at 2011 IRES

For three days crucial problems related to energy storage have been solved at Berlin Congress Center. Approximately 600 participants from all over the world made the sixth International Renewable Energy Storage Conference and Exhibition (IRES) the world’s biggest “industry event” for professionals coming from science and industry. “The storage of energy is the key to the future use of renewable sources – and thus crucial for the success of the ongoing energy revolution”, explained Irm Scheer Pontenage, managing director of EUROSOLAR, who hosts this world’s leading forum focused on tomorrow’s storage technologies cooperating with the Energy Agency NRW and many other well-known supporters.
Experts from home and abroad discussed almost every facet of storing energy generated from renewable sources, the technical possibilities, progress in development till the introduction of individual systems. Dipl.-Ing. Fabian Roesler presented the work of LTTT to improve efficiency of air/water-heatpumps by integration of latent heat storage in the Bavarian Research Cooperation FORETA.

EUROSOLAR press information for download.

Three promotions at LTTT

Within a short period of time three former members of staff, meanwhile working in industry, have received a PhD degree.


S. Manasra (2nd from right) with his examiners, Professors Jess, Rieg, Brüggemann and Mayinger (TU München).

On 19th September 2011 Salih Manasra, M.Sc. passed his doctoral exam with the dissertation “combustion and In-Cylinder Soot Formation Characteristics of a Neat GTL-Fueled DI Diesel Engine”.

C.Hüttl (center) after his doctoral degree exam with professors Rieg, Brüggemann, Moos and Jess.

On the same day Dipl.-Ing. Christian Hüttl who dealt the “Influence of Spray Propagation and Mixture Formation on the Combustion of Biodiesel-diesel Mixtures” received a PhD.

D. Böker in the middle of his examiners, Professors Willert-Porada, Moos, Brüggemann and Fischerauer.

On 14th October 2011 Dipl.-Ing. Dietmar Böker successfully did his thesis about “Laser-Induced Plasma for Ignition of Hydrogen-Air Mixtures at Engine-Related Pressures”.

The Department LTTT wishes all the three candidates the best for the future.

Contribution of LTTT concerning Low Carbon Earth Summit 2011
The picture shows Dipl.-Ing. F. Heberle in front of the conference building in Dalian.

Nearly 600 experts in the field of power generation came together for Low Carbon Earth Summit 2011 in Dalian (China) from 19th to 26th October. They discussed approaches for low-emission and sustainable energy supply. Renewable energies as well as political constraints were the most important topics of the conference.
At the meeting “Geothermal Energy” Dipl.-Ing. F. Heberle presented his research results on the use of zeotropic fluid mixtures as working fluids in Organic Rankine Cycle.

Ms Theresa Weith, M.Sc. receives VDI-Award 2011
From left: M. Preißinger, Th. Weith and Prof. Brüggemann

After finishing her Bachelor of Engineering Science at FAN, Ms Theresa Weith started her MSc in Energy Science and Technology. She was best of the year and passed it with distinction (overall grade 1,0) in July 2011. Her master thesis was entitled: “Mathematical analysis of thermodynamic data models and outline of optimization functions for ORC systems” for which she also received the best score. The Organic Rankine Cycle (ORC) which enables to convert relatively small amounts of heat into electrical power at low temperatures is the main topic of her thesis. She continues her work in this area at the Department of Engineering Thermodynamics and Transport Processes in the Center for Energy Technology at the University of Bayreuth as a scientific staff member and as a Ph.D. candidate. During her entire studies Ms Weith had excellent results which have now been honored with the VDI Award 2011.


LTTT at Thermodynamics Symposium 2011
From left: M. Preißinger, Th. Weith and Prof. Brüggemann

The annual meeting „Symposium on Applied Thermodynamics “ organized by ProcessNet “Thermodynamics” and by the scientific committee “Thermodynamics” of VDI, society for energy and environment, took place in Frankfurt from October 4th to October 6th.
Over 150 scientists discussed the latest research results in the field of engineering thermodynamics.
LTTT and the Zentrum für Energietechnik (ZET) (= Center for Energy Engineering) presented energy-efficient facades, thermal stores, power generation using Organic Rankine Cycle as well as the activities concerning the research of engines and soot with posters. Dipl.-Ing. Markus Preißinger gave a lecture on his results concerning “Thermodynamics and heat transfer of supercritical Organic Rankine Cycle at high temperatures” within the session “Thermodynamics of energy conversion”.

ORC 2011 – First International Seminar on ORC Power Systems
From Left: F. Heberle, Th. Weith, Prof. D. Brüggemann and M. Preißinger in front of the congress Center of the TU of Delft.

The first international ORC Conference took place in Delft on 22nd and 23rd September. It was dedicated to Professor Gianfranco Angelino for his contribution to the development of ORC technology.
Dipl.-Ing. M. Preißinger and Dipl.-Ing. F. Heberle presented their research activities in this field. In addition to studies on the use of supercritical Organic Rankine Cycle for waste heat recovery at high temperatures, results of exergoeconomic analysis of a geothermal Organic Rankine Cycle with zeotropic fluid mixtures were presented.
The conference provided the staff of LTTT the opportunity to learn about the latest developments and research activities around the Organic Rankine Cycle and to exchange information with international experts.


It’s all in the mix: power generation from geothermal heat

Organic Rankine Cycle has got a central role in the production of power from heat. A staff around Prof. Dr.-Ing. Dieter Brüggemann (Center for Energy Technology) has now published new results in order to increase the efficiency of geothermal power plants. Dipl.-Ing. Forian Heberle has significantly contributed to this research.

fico_pdf  Entire contents of press information for download.

Martin Zeil’s (Minister for Economic Affairs) funding decision for pioneering research project.

The potential for power generation from industrial waste has long been known, but a technically advanced and economical solution is not commercially available yet. The situation should be different now with a research project of the Department for Engineering Thermodynamics and Transport Processes (Head: Prof. Dr.-Ing. Dieter Brüggemann) from the University of Bayreuth funded by the Bavarian Research Foundation. Prof. Brüggemann cooperates with the University of Applied Science – Fachhochschule Amberg-Weiden (Prof. Dr.-Ing. Andreas Weiß) and with DEPRAG SCHULZ GmbH & CO in Amberg.

In order to underline the high level of innovation and the relevance of the research project, the Bavarian Minister of Economic Affairs came to the Faculty of Engineering Science and approved of the project by granting the project partners an amount of 325.000 €.

fico_pdf Entire contents of press information for download.

From left: Martin Zeil, MdL, Bavarian State Minister for Economic Affairs, Infrastructure, Transport and Technology; Prof. Dr.-Ing. Dieter Brüggemann, Head of the Department for Engineering Thermodynamics and Transport Processes (LTTT) and director of the Center for Energy Technology at the University of Bayreuth, Dr.-Ing. Andreas Weiß, Dean of the Faculty of Mechanical Engineering / Environmental Engineering at the University of Amberg-Weiden; Dr.-Ing. Rolf Pfeiffer, managing partner of DERPRAG SCHULZ GmbH & Co.

Third ZIM-NEMO project meeting at LTTT
The picture shows the participants of the first ZIM-NEMO project meeting.

The third ZIM-NEMO project meeting “Thermal Process Optimization” took place at LTTT on 21st July. A total of 17 participants discussed current issues and approaches concerning the use of industrial waste heat at low temperatures. The focus of this meeting was put on power generation by means of Organic Rankine Cycle (ORC).
Dipl.-Ing. Florian Heberle (LTTT) gave an introducing lecture. He explained the thermodynamic principle of ORC, differences to Rankine Cycle working on the basis of water-steam and how industrial waste heat can be used. Mr. Timm, GMK (ORC producers) gave a lecture on ORC systems already implemented in the range of 60 kW till 3 MW.

The meeting was followed by a guided tour of the laboratories and the discussion of further interaction of network partners.

Paper presented at Nanoparticle Conference at ETH
From left: W. Mühlbauer, U. Leidenberger

About 300 scientists met in Zurich from 26th to 29th June 2011 on the occasion of the 15th ETH Conference on Combustion Generated Nanoparticles. Wolfgang Mühlbauer and Ulrich Leidenberger from LTTT presented papers showing current results from optical investigations concerning the influence of diesel engine operating parameters on the physical and chemical properties of emitted soot.


LTTT at Symposium “Electrical Energy from Biomass”

The symposium “Electrical Energy from Biomass”took place at the Hochschule Zittau/Görlitz from 12th to 13th May 2011. Experts coming from industry and research presented papers and discussed the different ways of producing energy from biomass.
Dipl.-Ing. Markus Preißinger presented the research activities of LTTT in the field of Organic Rankine Cycle (ORC). In the context of his lecture “ORC process based on biomass – present use and approaches for optimization”, thermodynamic and plant-specific measures for optimization were discussed. In addition, the measures were evaluated according to their economic benefit. Thus it could be shown how future plants could work both more efficiently and more economically.

LTTT mit Beitrag zum World Renewable Energy Congress 2011
The picture shows Dipl.-Ing. Florian Heberle in front of the Congress building in Linköping (Sweden).

600 scientists coming from 70 countries came together on the occasion of World Renewable Energy Congress (WREC) 2011 in Linköping from 8th to 13th May in order to discuss innovative technologies and current research in the field of renewable energies. It was about applications in the field of solar, wind and water energy as well as the use of biomass and geothermal power.
Further topics were climate change, sustainable transport and energy efficient buildings. Dipl.-Ing. F. Heberle from LTTT presented the thermodynamic and economic analysis of a coupled heat and power supply for geothermal applications. Different concepts of combined heat generation as a function of selected operating parameters were compared.

X. International Conference – Engine Combustion
HdT Gruppe
From left: S. Lorenz, U. Leidenberger, Prof. Brüggemann and W. Mühlbauer

For the tenth time the International Congress „Engine Combustion – Current Problems and Modern Approaches“ organized by Professor Dr.-Ing. Alfred Leipertz from the Erlangen Department of Engineering Thermodynamics took place in Munich from 24th to 25th March 2011. In this context, Dipl.-Ing. U. Leidenberger gave a lecture entitled “influence of diesel engine parameters and the resulting combustion on emitted soot”. Furthermore, LTTT presented posters concerning laser-induced exciplex-fluorescence with alternative fuels. In addition to Professor Brüggemann, W. Mühlbauer and S. Lorenz from LTTT staff were present.


LTTT gives a lecture on waste heat recovery in industry.
The Chamber of Commerce and Industry of Upper Franconia invited to the 4th Environment and Energy Workshop meeting at Kaliko GmbH in Bamberg on April 5th 2011. In this meeting energy efficient measures for industry were discussed.
Dipl.-Ing. Markus Preißinger from LTTT explained ways to use industrial waste heat in his presentation “Use of Waste Heat for Decentralized Power Generation – the ORC-Process”. The presentation as well as the guided tour of Kaliko GmbH, Bamberg, served as a basis for further discussion showing the importance of an efficient use of energy, particularly in industry at present times.

Network foundation for thermal process optimization

Ten companies whose fields of activity are the materials-processing industry and two research groups from Bayreuth have set up an entrepreneurial platform for intelligent energy efficient solutions. The project, funded by the Federal Economics Ministry within the framework of ZIM-funding program, was presented on the occasion of a press conference held in the Kompetenzzentrum für Neue Materialien (Center of Competence for New Materials) in Bayreuth on Friday 1st April where the Stadt Bayreuth, Neue Materialien Bayreuth GmbH und further project partners had invited. The Department of Engineering Thermodynamics and Transport Processes takes over the scientific support for this project. Thus, for example, the knowledge of LTTT can be included by showing the latest results from research on process heat generation and application.

Entire content of press information for download.

The picture shows the participants of the first ZIM-NEMO meeting.

News from the years 2010 and earlier are only available on german.