Pore scale 3D modelling of heat and mass transfer in the gas diffusion layer and cathode channel of a PEM fuel cell

Abstract

a b s t r a c tFlooding of the gas diffusion layer (GDL) of proton exchange membrane (PEM) fuel cells can be a bottleneck to the system's efficiency and even durability under certain operating conditions. Due to the small scale and complex geometry of the materials involved, detailed insight into the pore scale phenomena that take place are difficult to measure or simulate. In the present effort, a direct 3D microscale model of a portion of the PEM cathode channel and carbon cloth GDL is used to parametrically investigate local heat and fluid flow at the GDL's pore scale and their effects on condensation of water vapour that leads to flooding. The 3D simulation through the microscale geometry is among the first appearing in the international literature. The NaviereStokes, energy and water vapour transport equations are solved at steady state and in three-dimensional space for a range of inlet velocities and cloth fibre material properties, using a conjugate heat transfer approach to calculate the temperature field within the solid fibres. Psychrometric calculations are applied to provide indications of the conditions and areas most prone to condensation based on the calculated local temperatures and water vapour concentration.

Comparative design study of a diesel exhaust gas heat exchanger for truck applications with conventional and state of the art heat transfer enhancements

“…(27) [21] is in general agreement with the data calculated by computational fluid dynamics simulation in [30] for the 40 ppi foam but it underestimates the heat transfer coefficient by ~ 25% if the exhaust gas side is filled with a 10 ppi foam. Therefore some "fine tuning" of Eq.…”

“…(25) is used [20]. Kopanidis et al [30] were used and found very close to the value of the porosity of the material.…”

“…This is not readily available for metal foam and so the present model has adopted the equation form of Lu et al [21], who considered that the opencelled foam is made up of uniform distributed, equal-sized cubic cells. The actual cell shape is more complex [30] but the cubic unit cell has been chosen for its simplicity and …”

Degradation aspects of water formation and transport in Proton Exchange Membrane Fuel Cell: A review

“…Numerical simulations of the water transport through different types of GDL were carried out in numerous investigations [344][345][346][347][348][349][350][351][352][353][354][355][356][357][358]. The majority of these two-and three-dimensional models suggest that the transport of liquid water through GDL is mainly dominated by the hydrophobic and morphological properties of the GDL including porosity, tortuosity, cross sectional area, thickness, and PTFE loading.…”

A Different Flow Field Design Approach for Performance Improvement of a PEMFC

“…Fuel cells are a developing energy technology, which offers major advantages and wide range of applications for mobile, transportation and stationary systems [1]. These advantages include high energy efficiency, quiet operation without vibration, portability and almost zero emissions [2].…”