Optimizing power to hydrogen focusing on PEM electrolyzers
Pornbunditwong, Kanokporn (2025)
Kandidaatintyö
2025
School of Energy Systems, Energiatekniikka
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Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi-fe2025090193335
https://urn.fi/URN:NBN:fi-fe2025090193335
Tiivistelmä
This thesis investigates the performance optimization of Proton Exchange Membrane Electrolyzers (PEME) within Power-to-Hydrogen (P2H) systems. The main objective is to develop a semi-empirical model capable of predicting the electrochemical behavior of a PEME cell under varying operating conditions, with particular focus on current density and its impact on energy and exergy efficiencies.
The methodology combines theoretical modeling and MATLAB-based simulations. The PEME cell voltage is calculated using a polarization curve derived from the reversible voltage and overpotential contributions, including activation, ohmic, and concentration losses. Parametric analysis is conducted over a range of current densities to evaluate hydrogen production rate, cell efficiency, and sensitivity to key parameters such as ohmic resistance and limiting current density.
Results indicate that increasing current density leads to higher hydrogen production but decreases both energy and exergy efficiencies due to rising overpotentials. A linear approximation model is also validated for simplified control applications in dynamic operations. The findings provide insights for optimal operation of PEME systems integrated with renewable energy sources, contributing to improved efficiency and reduced cost in future hydrogen production infrastructures.
The methodology combines theoretical modeling and MATLAB-based simulations. The PEME cell voltage is calculated using a polarization curve derived from the reversible voltage and overpotential contributions, including activation, ohmic, and concentration losses. Parametric analysis is conducted over a range of current densities to evaluate hydrogen production rate, cell efficiency, and sensitivity to key parameters such as ohmic resistance and limiting current density.
Results indicate that increasing current density leads to higher hydrogen production but decreases both energy and exergy efficiencies due to rising overpotentials. A linear approximation model is also validated for simplified control applications in dynamic operations. The findings provide insights for optimal operation of PEME systems integrated with renewable energy sources, contributing to improved efficiency and reduced cost in future hydrogen production infrastructures.