# Dr. Pascal Richter

For my PostDoc I have moved to IGPM institute.

New Webpage:
www.igpm.rwth-aachen.de/team

Personal Webpage:
www.solar.rwth-aachen.de

richter@igpm.rwth-aachen.de

For my PostDoc I have moved to IGPM institute.

IGPM and AICES
Department of Mathematics
RWTH Aachen University
Schinkelstr. 2a
D-52062 Aachen
Germany

Room: GRS.202 (GRS building, 2nd floor)
Phone: +49 (0)241 80 99 745
Email: Pascal Richter
Office Hours: By appointment, please send me an Email

After my studies of mathematics and computer science at RWTH Aachen University I am now a research assistant and PhD student in the group of Prof. Frank. Furthermore, I am an associated fellow at the Aachen Institute of Advanced Study in Computational Engineering Science (AICES).

• 09/2012 Awarded for best presentation overall at the annual meeting of the German Mathematical Society (DMV), September 16–20, 2012 in Saarbrücken, Germany
• 06/2012 Awarded the Springorum medal
• 05/2011 Received Diploma degree in Mathematics with distinction
• 12/2009 Received Diploma degree in Computer Science

# Research

Concentrated solar power systems are systems that use mirrors to concentrate sunlight to heat a fluid. The heated fluid is converted into steam which drives a turbine to generate electrical power.

There exist different types of concentrators. For example, Fresnel reflectors (see figure) are made of many thin, flat mirror strips that concentrate sunlight onto tubes through which a working fluid is pumped. The idea of direct steam generation is to use water as the working fluid.

In this project we consider the flow of water inside an absorber tube. This two-phase flow is modeled as a homogeneous flow. Specifically, the flow is governed by the 1D Euler equations. The influence of solar energy is described by a heat equation which is coupled with the flow. Due to a specific closure relation for the two-phase flow, the system is in a non-conservative form. We will develop a model and numerical schemes to simulate the flow through a realistic network of tubes.

#### Publications

• Richter, P. ; Tinnes, J. ; Schwarzbözl. P. ; Frank, M.: Efficient Ray-Tracing with Real Weather Data , In Proceedings of the 23rd International Conference, SolarPACES, Preprint, 2017 .
• Richter, P. ; Wolters, J. ; Cakar, R. ; Verhoeven-Mrosek, A. ; Frank, M.: Uncertainty quantification of wind farm models, Preprint, 2017 .
• Müller, S. ; Hantke, M. ; Richter, P.: Closure conditions for non-equilibrium multi-component models, Continuum Mechanics and Thermodynamics, 1-33, Springer, 2015 .
• Richter, P. ; Frank, M. ; Ábrahám, E.: Multi-objective optimization of solar tower power plants, In Proceedings of European Conference on Mathematics for Industry (ECMI 2014) .
• Richter P.: Modellierung und Simulation der Direktverdampfung in Absorberrohren solarthermischer Kraftwerke, Diploma Thesis in Mathematics, RWTH Aachen University, 2011 .
• Richter, P.; Ábrahám, E. ; Morin, G.: Optimisation of Concentrating Solar Thermal Power Plants with Neural Networks. In Proceedings of International Conference on Adaptive and Natural Computing Algorithms (ICANNGA’11). LNCS, Vol. 6593, pp. 190–199. Springer-Verlag, 2011 .
• Morin, G.; Richter, P.; Nitz, P.: New method and software for multi-variable techno-economic design optimisation of parabolic trough power plants , In Proceedings of the 16th International Conference, SolarPACES 2010 .
• Richter P.: Simulation und Auslegungsoptimierung solarthermischer Kraftwerke unter Einsatz evolutionärer Algorithmen und neuronaler Netze, Diploma Thesis in Computer Science, RWTH Aachen University, 2009 .

#### Talks

• Richter, P.: Multi-objective optimization of solar tower power plants, 18th European Conference on Mathematics for Industry, ECMI 2014, June 9-13 2014, Taormina, Italy .
• Richter, P.: Modelling and simulation of direct steam generation in solar thermal power plants, DMV Annual Meeting 2012, September 17-20 2012, Saarbrücken, Germany.
• Richter, P.; Abraham, E.; Morin, G.: Optimisation of solar thermal power plants with artificial intelligence, 10th International conference, ICANNGA 2011, April 14-16 2011, Ljubljana, Slovenia.
• Morin, G.; Richter, P.; Nitz, P.: New method and software for multi-variable techno-economic design optimisation of parabolic trough power plants , 16th International conference, SolarPACES 2010, September 21-24 2010, Perpignan, France.

#### Poster

• Together with Richard Barnard (University of Graz), Elena Botoeva (Free University of Bozen) and Dirk Surmann (Technical University of Dortmund) we recently finished a LaTeX document class called tikzposter for the easy generation of scientific posters . It is available on CTAN. Here you can find the manual.

# Projects

For students of Mathematics, Computer Science or CES I offer diploma, master or bachelor theses out of the research project of solar thermal power systems. I am also offering projects on the basis of a paid student employment ('HiWi'). The thematics typically incorporate multi-disciplinary aspects ran­ging from analysis and engineering to implementation. If you are interested please send an Email.

#### Thesis in Mathematics, Computer Science or CES

Implementation of a web application (Bachelor thesis)
Solar towers use many mirrors to concentrate sun light on a central, tower-mounted receiver. The receiver then transfers the resulting heat to a fluid (i.e. molten salt or air) that, in turn, exchanges the heat to steam which powers a turbine, generating electricity. The placement of the mirrors may lead to individual mirrors being blocked and shaded; this affects the efficiency (and therefo- re costs) of the power plant. The model is later used for an optimisation process which finds the most efficient arrangement of mirrors. In this thesis a web application has to be implemented. Detailed information on this project can be found here.

Optimisation of solar tower power plant (Master or Diploma thesis)
The exploitation of solar power for energy production is of increasing importance. Solar towers use many flat mirrors to concentrate sun light on the absorber, which is mounted on a tower. This absorber warms a medium (i.e. water) that powers a turbine which in turn generates electricity. The mirrors' placement may lead to individual mirrors being blocked and shaded; this affects the efficiency (and therefore costs) of the power plant. The goal is to find the most efficient arrangement of mirrors that balances power production against construction costs. Detailed information on this project can be found here or here

Direct steam simulation of solar thermal power plants (Bachelor or Master thesis)
In this project we consider the flow of water inside an absorber tube. This two-phase flow is governed by the 1D Euler equations which are coupled with a heat equation modelling the solar irradiance. Possible topics for theses include implementation of various numerical schemes.

More open projects can be found here.

#### HiWi Jobs

Out of the research field we offer a paid student employment ('HiWi') for programming in C++. Detailed information on this job can be found here.