Zero-dimensional dynamic modeling of PEM electrolyzers

Paolo Colbertaldo, Sonia Laura Gómez Aláez, Stefano Campanari
2017 Energy Procedia  
District heating networks are commonly addressed in the literature as one of the most effective solutions for decreasing the greenhouse gas emissions from the building sector. These systems require high investments which are returned through the heat sales. Due to the changed climate conditions and building renovation policies, heat demand in the future could decrease, prolonging the investment return period. The main scope of this paper is to assess the feasibility of using the heat demand
more » ... door temperature function for heat demand forecast. The district of Alvalade, located in Lisbon (Portugal), was used as a case study. The district is consisted of 665 buildings that vary in both construction period and typology. Three weather scenarios (low, medium, high) and three district renovation scenarios were developed (shallow, intermediate, deep). To estimate the error, obtained heat demand values were compared with results from a dynamic heat demand model, previously developed and validated by the authors. The results showed that when only weather change is considered, the margin of error could be acceptable for some applications (the error in annual demand was lower than 20% for all weather scenarios considered). However, after introducing renovation scenarios, the error value increased up to 59.5% (depending on the weather and renovation scenarios combination considered). The value of slope coefficient increased on average within the range of 3.8% up to 8% per decade, that corresponds to the decrease in the number of heating hours of 22-139h during the heating season (depending on the combination of weather and renovation scenarios considered). On the other hand, function intercept increased for 7.8-12.7% per decade (depending on the coupled scenarios). The values suggested could be used to modify the function parameters for the scenarios considered, and improve the accuracy of heat demand estimations. Abstract The transition to a low-carbon system foresees the introduction of hydrogen as a clean energy vector. Electrolyzers play a key role in its production from renewable energy, and PEM technology seems the most promising alternative thanks to efficiency, flexibility and compactness. Modeling the device dynamic behavior allows investigating its combination with renewable electricity sources. A dynamic 0D model is developed using Aspen Custom Modeler, including a detailed description of the various phenomena involved in the electrochemical process. General formulations are implemented and multiple options for correlations are present, when available. The model is validated against available literature data, showing an appropriate reconstruction of the cell behavior. Unsteady behavior is studied and the role of thermal capacity is shown, under a test-case with a simple operating input profile. Abstract The transition to a low-carbon system foresees the introduction of hydrogen as a clean energy vector. Electrolyzers play a key role in its production from renewable energy, and PEM technology seems the most promising alternative thanks to efficiency, flexibility and compactness. Modeling the device dynamic behavior allows investigating its combination with renewable electricity sources. A dynamic 0D model is developed using Aspen Custom Modeler, including a detailed description of the various phenomena involved in the electrochemical process. General formulations are implemented and multiple options for correlations are present, when available. The model is validated against available literature data, showing an appropriate reconstruction of the cell behavior. Unsteady behavior is studied and the role of thermal capacity is shown, under a test-case with a simple operating input profile.
doi:10.1016/j.egypro.2017.12.594 fatcat:kr2s7a4npveonndui4se7ggyiu