Simulation of Load Profiles for the Application of a SOFC CHP System as controllable Power Plant of the Future

Benjamin Königshofer

Research output: ThesisMaster's Thesis

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Abstract

Electricity and thermal power are the two most important forms of energy in the contemporary world. Cogeneration (CHP) technologies combine the production of electricity and heat and can be divided into internal combustion engine based cogeneration systems, turbine based cogeneration systems and fuel cell based cogeneration systems. Solid oxide fuel cells (SOFC) are known to achieve higher electrical efficiencies and produce fewer emissions compared to conventional cogeneration technologies. Although, SOFCs are opening up new business fields, the commercial market segments for the SOFC technology are still very narrow. Therefore, the suitability of the technology for different applications needs to be tested to unlock new opportunities and market sectors. This report first gives a literature review in the form of a technical and economical comparison of SOFCs with commercial available gas turbines and gas engines in the power range up to 10 megawatts. The scope of this review covers a wide range of comparison parameters from efficiencies and emissions over power ramping behavior to maintenance efforts and comprehensive costs analysis. Furthermore, a model is compiled, which simulates the behavior of SOFC CHP systems to specify the suitability of the technology for different applications. The results of the simulation are combined with the technical and economical comparison, in order to determine the requirements for SOFC CHP systems as controllable power plants of the future. Compared to commercial reference technologies, SOFCs present major advantages regarding electrical efficiency, emissions and maintenance efforts. Nevertheless, additional development, especially on the fuel cell stack is necessary to improve performance degradation rates, initial costs and scalability. The results of the simulation show the suitability of SOFCs for multiple applications like continuous operation, prime with additional feed-in to the grid, island as well as supply of control energy. While SOFC CHP systems can compete with gas turbines and gas engines in most of the residual comparison parameters, especially the start-up time and ramp rates are very depended on the specific application. Nevertheless, every single application needs a very specific system configuration and operational mode in order to fulfill the technical and economical requirements. Furthermore, minor compromises regarding electrical and thermal cover ratio, surplus produced energy and full load hours are often indispensable. The major challenges occurred on the basis of the varying stack temperature, which is the limiting factor of the technology and strongly influences start-up time, ramp-rates and reliability of power production.
Translated title of the contributionSimulation von Lastprofilen für den Einsatz eines SOFC CHP Systems als regelbares Kraftwerk der Zukunft
Original languageEnglish
QualificationDipl.-Ing.
Awarding Institution
  • Montanuniversität
Supervisors/Advisors
  • Kriechbaum, Lukas, Co-Supervisor (internal)
  • Kienberger, Thomas, Supervisor (internal)
Award date29 Jun 2018
DOIs
Publication statusPublished - 2018

Bibliographical note

embargoed until 27-06-2023

Keywords

  • simulation
  • load
  • profile
  • SOFC
  • CHP
  • power
  • plant
  • gas
  • turbine
  • engine

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