Investigation of water droplet kinetics and optimization of channel geometry for PEM fuel cell cathodes

Akhtar, N Naveed; Qureshi, Arshad Hussain; Scholta, Joachim; Hartnig, Christoph; Messerschmidt, M.; Lehnert, Werner

doi:10.1016/j.ijhydene.2009.01.022

Cited by 83 publications

(36 citation statements)

References 54 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Considering these results, the channel height of 0.5 mm may be concluded to be superior for draining the droplets since the drainage speed is also high. This optimum channel shape was also reported in the experimental work of Akhtar et al from a different viewpoint [17]. They concluded from the experiments of a droplet detachment in a channel that the rectangular shaped channel with a width of 1 mm and a depth of 0.5 mm is found to exhibit best water removal properties at a reasonable pressure drop.…”

Section: --17supporting

confidence: 80%

Two phase flow simulation in a channel of a polymer electrolyte membrane fuel cell using the lattice Boltzmann method

Yasser

Tabe

Chikahisa

2012

Journal of Power Sources

View full text Add to dashboard Cite

Water management in polymer electrolyte (PEM) fuel cells is important for fuel cell performance and durability. Numerical simulations using the lattice Boltzmann method (LBM) are developed to elucidate the dynamic behavior of condensed water and gas flows in a polymer electrolyte membrane (PEM) fuel cell gas channel. A scheme for two-phase flow with large density differences was applied to establish the optimum gas channel design for different gas channel heights, droplet positions and gas channel walls wettability. The present simulation using the LBM, which considers the actual physical properties of the system, shows the effect of the cross-sectional shape, the droplet initial position, droplet volume and the air flow velocity for both hydrophobic and hydrophilic gas channels. The discussion of optimum channel height and drain performance was made using two factors "pumping efficiency" and "drainage speed". It is shown that deeper channels give better draining --2 efficiency than shallower channels, and the efficiency remains largely unchanged when the droplet touches corners or the top of walls in the gas channel. As the droplet velocity, i.e. the drainage flow rate, becomes higher and the drainage efficiency becomes less dependent on droplet locations with shallower channels, shallower channels are better than deeper channels as the pumping efficiency is not greatly affected. Introducing a new dimensionless parameter, "pumping efficiency", the investigation discusses the effect of the various parameters on the drainage performance of a PEM fuel cell gas channel.

show abstract

Section: --17supporting

confidence: 80%

Two phase flow simulation in a channel of a polymer electrolyte membrane fuel cell using the lattice Boltzmann method

Yasser

Tabe

Chikahisa

2012

Journal of Power Sources

View full text Add to dashboard Cite

show abstract

“…To guide droplets, Seo et al 40 converted superhydrophobic Si nanowire arrays to hydrophilic patterns using a UV-enhanced method photodecomposition of the dodecyltrichlorosilane (DTS), and such method is reproducible on the same surface. Similar guidance behavior was attained by fixing a line-patterned groove on a hydrophobic surface by Sommers et al 41 Compared with the methods mentioned in the first paragraph, droplet transporting on solid surfaces by wetting anisotropy is without an additional controlling equipment, and is of potential importance in many industrial applications such as water drainage in the proton exchange membrane fuel cells (PEMFCs) [42][43][44] . Despite significant progress on the fabrication of wetting anisotropy and the validation of control, it remains elusive that how and to what extent the wetting anisotropy can modulate the transporting behavior of droplets.…”

Section: I I Introduction Ntroduction Ntroduction Ntroductionmentioning

confidence: 68%

No-Loss Transportation of Water Droplets by Patterning a Desired Hydrophobic Path on a Superhydrophobic Surface

Song

2016

Langmuir

View full text Add to dashboard Cite

The directional transportation of droplets on solid surfaces is essential in a wide range of engineering applications. It is convenient to guide liquid droplets in a given direction by utilizing the gradient of wettability, by which the binding forces can be produced. In contrast to the mass-loss transportation of a droplet moving along hydrophilic paths on a horizontal superhydrophobic surface, we present no-loss transportation by fabricating a hydrophobic path on the same surface under tangential wind. In experimental exploration and theoretical analysis, the conditions of no-loss transportation of a droplet are mainly considered. We demonstrate that the lower (or upper) critical wind velocity, under which the droplet starts on the path (or is derailed from the path), is determined by the width of the path, the length of the contact area in the direction parallel to the path, the drift angle between the path and the wind direction, and the surface wettability of the pattern. Meanwhile, the no-loss transportation of water droplets along the desired path zigzagging on a superhydrophobic surface can be achieved steadily under appropriate conditions. We anticipate that such robust no-loss transportation will find an extensive range of applications.

show abstract

“…Channel and rib widths between 0.7 and 1 mm were identified as being optimum under the operating conditions considered. Akhtar et al [19] investigated the importance of channel depth on performance. They measured the cell voltage (V) for channel depths of 1.5, 1 and 0.6 mm in a parallel based flow field and found the lowest channel depth of 0.6 mm to be most advantageous.…”

Section: Channel Geometrymentioning

confidence: 99%

“…Akhtar et al [19] also investigated square, rectangular and triangular-shaped channels. However, they found the optimum geometry for the best water removal at a reasonable pressure using a parallel flow field was found to be a rectangular-shaped channel with a width of 1 mm and a depth of 0.5 mm.…”

Section: Channel Geometrymentioning

confidence: 99%

Polymer Electrolyte Membrane Fuel Cell (PEMFC) Flow Field Plate: Design, Materials and Characterisation

2010

View full text Add to dashboard Cite

Worldwide, there are growing pressures to develop 'carbonfree' societies, where the majority of the energy is produced from renewable technologies, due to climate change [1], adverse health effects [2], fuel resource depletion [3], security of energy supply, economics [4] and increasing tight international legislations [5]. In response to the above issues, many have proposed hydrogen for use as a replacement energy carrier in future energy economies as it produces no greenhouse gases, GHGs (e.g. CO 2 ) when burned or used in a fuel cell with only electricity, heat and water being formed. A fuel cell is an 'electrochemical' device operating at various temperatures (up to 1,000°C) that continuously and efficiently convert chemical energy (from fuel and oxidant) into electrical energy. There are various types of fuel cell including alkaline (AFC), phosphoric acid (PAFC), molten carbonate (MCFC), solid oxide (SOFC) and polymer electrolyte membrane fuel cell (PEMFC) also known as the proton exchange membrane fuel cell (PEMFC) with an efficiency of up to 60% and operating up to 180°C. There are two types of PEMFC: one uses hydrogen as a fuel and the other, methanol -direct methanol fuel cell (DMFC). They both use membrane electrode assemblies (MEAs) which is the heart of the PEM fuel cell where the electrochemical reactions occur. The MEA is a multilayered membrane consisting of a polymeric membrane sandwiched between catalyst layers and gas diffusion layers (GDLs). Currently, the most promising applications for PEM fuel cell are in the automotive sector with trials of buses, cars and motorcycles becoming increasingly common. Others applications include portable, stationary or backup power units. However, the cost, performance and durability still need to be improved if PEMFC is to become a viable alternative energy technology. For example, as 'a rule of thumb', flow field plates (FFPs) constitute 10% (7.7% for a 5 kWnet stack) of the total cost and more than 60% of the weight in PEM fuel cell stacks. For this reason, the weight, volume and cost of the fuel cell stack can be reduced significantly by improving the layout configuration of FFP and use of lightweight materials. Different combinations of materials, flowfield designs and fabrication techniques have been developed for FPPs to achieve the aforementioned functions efficiently, with the main scope of obtaining high performance and economic advantages. Introduction to Flow Field PlatesThe FPP, also known as the monopolar plate (in a single cell) and bipolar plate (BPP, when used in a stack), is one of the many important components of PEM fuel cell stacks as it supplies fuel and oxidant to the MEA, removes water, collects produced current and provides mechanical support for the single cells in the stack (Figure 1) AbstractThis review describes some recent developments in the area of flow field plates (FFPs) for proton exchange membrane fuel cells (PEMFCs). The function, parameters and design of FFPs in PEM fuel cells are outlined and considered in light of their ...

show abstract

Investigation of water droplet kinetics and optimization of channel geometry for PEM fuel cell cathodes

Cited by 83 publications

References 54 publications

Two phase flow simulation in a channel of a polymer electrolyte membrane fuel cell using the lattice Boltzmann method

Two phase flow simulation in a channel of a polymer electrolyte membrane fuel cell using the lattice Boltzmann method

No-Loss Transportation of Water Droplets by Patterning a Desired Hydrophobic Path on a Superhydrophobic Surface

Polymer Electrolyte Membrane Fuel Cell (PEMFC) Flow Field Plate: Design, Materials and Characterisation

Contact Info

Product

Resources

About