Design and Dynamic Modelling of a 40 kW Solid Oxide Electrolysis System
Author
Azevedo Fialho de Oliveira Pinto, Miguel
Term
4. term
Education
Publication year
2025
Submitted on
2025-05-28
Pages
54
Abstract
Electrolysis offers a cleaner way to produce hydrogen than fossil fuel-based methods. High-temperature electrolysis is especially attractive because reactions proceed more readily and quickly at elevated temperatures than in low-temperature systems. This thesis develops a one-dimensional, dynamic computer model of a 40 kW Solid Oxide Electrolyzer Cell (SOEC) stack, a high-temperature device that splits steam into hydrogen and oxygen. The model couples electrochemical kinetics with mass and energy balances to study how the stack responds to sudden changes in power input (step load changes). The cell is divided into segments along its length to track temperature and gas composition, and supporting equipment such as heat exchangers and electric heaters is included. The results show an overall efficiency above 80% during the simulated period. Transient responses to step changes were stable, with temperature gradients staying below 10 K/cm. Over a 10-hour simulation, the stack produced about 7 kg of hydrogen with a specific energy consumption near 34 kWh/kg. These findings indicate that SOECs are well suited for flexible hydrogen production and can be integrated into renewable-based energy systems.
Elektrolytisk produktion af brint er et renere alternativ til fossile metoder. Højtemperatur-elektrolyse er særligt lovende, fordi reaktionerne forløber lettere og hurtigere ved høje temperaturer end ved lavtemperatur-elektrolyse. I dette projekt udvikles en endimensionel, dynamisk computermodel af en 40 kW fastoxid-elektrolysestak (SOEC), som spalter vanddamp til brint og ilt. Modellen kombinerer elektrokemisk kinetik med masse- og energibalancer og undersøger, hvordan stakken reagerer på pludselige ændringer i effekt (trinvis belastning). Cellen opdeles i længdesegmenter for at følge temperatur- og sammensætningsprofiler, og hjælpeudstyr som varmevekslere og elvarmere indgår også. Resultaterne viser en samlet virkningsgrad på over 80 % i den simulerede periode. Under trinvise belastningsændringer var forløbet stabilt, og temperaturgradienterne forblev under 10 K/cm. Over en 10 timers simulering producerede stakken cirka 7 kg brint med et specifikt energiforbrug tæt på 34 kWh/kg. Modellen peger på, at SOEC-teknologi er velegnet til fleksibel brintproduktion og kan indgå i energisystemer baseret på vedvarende kilder.
[This apstract has been rewritten with the help of AI based on the project's original abstract]
Keywords