Implementation of a Non-Discretized Multiphysics PEM Electrolyzer Model in Modelica

Abstract

In this paper a multi-physics model of a proton exchange membrane electrolyzer with selectable physics submodels is developed in Modelica R. It will be included in the open-source TransiEnt Library for future studies on the efficiency of energy storage for intermittent renewable sources and the coupling of power, gas, and heat grids. The model is derived almost explicitly from a previous research paper by (Espinosa-López et al., 2018) but uses different models for cooling system power and anode/cathode gas pressures. The model is then demonstrated in an application with wind speed records and corresponding power generation over the course of one year at a wind farm in northern Germany. It produces results similar to experimental results in other papers for use in general applications of further study.

Presentation, Validation and Application of the EnergyProcess Library

“…The PEM subpackage has a dedicated electrolyzer model, which itself includes several replaceable physics package such as voltage, temperature, converter and mass flow models. The latter model structure is largely inspired by the model from Webster and Bode (2019). Figure 3 represents an extract of the PEM highlighting its "physics" package.…”

“…At first, to validate the stack model, polarization curve using the cell voltage calculation by Webster and Bode (2019) and Afshari et al (2021) are compared to the NREL data (Harrison, 2021). The resulting I-V curves are given in Figure 7.…”

Importance of Model Fidelity of Power to X Devices in Energy System Analysis

“…The last term comes from enthalpy lost with the products leaving the system, it has an empirical equation that depends on the operating temperature. For more details, reader is refered to [13]. Considering Eqs.…”

“…The coefficient of performance (COP) of an electric heat pump depends on the choice of refrigerant and the Rankine cycle efficiency (Carnot efficiency) of the refrigerant inside the heat pump, as described in Eq. (13).…”

Status of the TransiEnt Library: Transient Simulation of Complex Integrated Energy Systems

“…The second technology, Power-to-Gas, uses electricity to generate hydrogen via electrolysis. The core component, the electrolyzer, is either modeled using an efficiency curve or more detailed physics of the electrolyzer (Webster and Bode 2019). Both models include either quasi-stationary, first-order, or second-order dynamics as well as the possibility to give a certain amount of waste heat to a connected component.…”