Optimization

Generating electricity from green hydrogen – with low-temperature polymer electrolyte membrane fuel cells, this can already be done very efficiently. But of course there is still room for improvement: For example, there is still considerable potential for increasing efficiency in optimized liquid water management.

The problem: accumulations of product water hinder oxygen transport, reduce performance and can shorten the service life of the fuel cells. The uneven distribution of water in the porous gas diffusion layers and the connected channel structures is particularly critical. Due to the complexity of the structures and physical phenomena, currently available simulative methods are not sufficiently accurate to enable industry-oriented optimization.

New flowfield designs enable

The FLOWMEX project aims to fundamentally improve water management in fuel cells. The focus is on the development and validation of a new, computationally efficient simulation tool that realistically maps the transport of liquid water in gas diffusion layers and flowfield channels. With the help of these models, new flowfield designs are developed, constructively evaluated and validated in test fuel cells.

The simulation model is provided as an open source tool. This also gives small and medium-sized enterprises (SMEs) the opportunity to develop components more efficiently and without expensive high-performance computers or commercial software.

Combine methods

Experimental investigations: Optical flow measurements, laser-optical methods (µPIV, LDV) and electrochemical tests on specially manufactured test cells

Numerical methods: Coupling of pore network and discrete particle models, validation with high-resolution VOF simulations and flow measurement data

Design & Transfer: Development and evaluation of new flowfield structures, production of test FCs and provision of the simulation model via a user-friendly web interface

Strengthening innovative strength

FLOWMEX provides practical design principles for bipolar plates and flowfields that could enable significant performance increases of 20 to 30 percent. Developed for fuel cell technology, the simulation model can also be transferred to other fields – such as electrolysis, filtration or medical technology.

The project thus makes an important contribution to the market ramp-up of hydrogen technologies and strengthens the innovative capacity of SMEs in Germany in particular.

Data

Project title:

• • FLOWMEX – FLOWfield structuringto improve water transport in fuel cells using model-basedand EXperimentalmethods

Project duration:

• • 2025 to 2027

Partners:

• • ZBT – The Hydrogen and Fuel Cell Center
  • Chair of Fluid Mechanics (LSM) at the University of Wuppertal