Influence of cathode stoichiometry on operation of PEM fuel cells’ stack supplied with pure oxygen

Abstract

As a part of ongoing research into the use of fuel cells to power underwater platforms, studies have been conducted to investigate the effect of change in oxygen flow through the proton exchange membrane fuel cell (PEM-FC) cathode channel, to develop a method for controlling this flow. Due to the lack of specific information or studies on the effect of pure oxygen flow through the PEM-FCs cathode channel on the correctness of its work, a series of experiments have been carried out within the framework of in-house research to determine this dependence. The experiment was conducted in series, during which the only change in the operating parameter of the PEM-FC stack was the stoichiometric flow rate of oxygen supplied to the cathode channel of the fuel cells' stack. The research shows that for the PEM-FCs stack fed with pure oxygen, the cathode stoichiometry can be kept at a much lower level comparing to the systems supplied with air. It has been found that the fuel cells' stack fed with pure oxygen will perform well in steady state while reducing the cathode stoichiometry by as much as 40% compared to systems utilising oxidant from atmospheric air.

Assessment of noise and vibration hazards generated by hybrid PEM-FC personal power supply

“…However, unlike hydrogen combustion, where energy is released in the form of heat, in the fuel cells, the chemical energy is converted into electrical energy that is observable as an electrical work. Transfer of positive ions is carried out by the electrolyte, while electrons are forced to move through the external electrical circuit doing useful work [3]. The operation of PEM-FC is based on a continuous chemical reaction whose speed is determined by the current drawn from the cell.…”

A New Integrated GDL with Wavy Channel and Tunneled Rib for High Power Density PEMFC at Low Back Pressure and Wide Humidity

“…Compared with air supply, pure oxygen can effectively suppress the oxygen concentration polarization at high current density. [ 8 ] The power density per unit area of fuel cells under pure oxygen supply can be 1.6‐3 times higher than that under air supply. [ 9 , 10 ] However, the production of pure oxygen is associated with extra costs and special devices.…”

Stokiyometri Oranının İki Hücreli PEM Yakıt Hücresi Yığını Performansına Etkisinin İncelenmesi

“…Yakıt hücrelerinin çalışmasına etki eden faktörler ile ilgili bir literatür taraması yapıldığında yakıt hücresi yığın performansına stokiyometrik oranın etkisinin incelendiği farklı çalışmalara ulaşılmıştır [10,[17][18][19][20][21]. Bu çalışmalarda sadece katot stokiyometrisinin etkisini dikkate alan [17], geri basınçlandırma ve anot stokiyometrisini inceleyen [18], hava stokiyometrisini yani katot stokiyometrisi dikkate alan [19], yük değişimi esnasındaki stokiyometri değişimini inceleyen [20], PEM yakıt hücresi çalışma koşullarının (akım yoğunluğu, çalışma sıcaklığı, katot stokiyometrisi, vb.) ısı ve su oluşumu üzerine etkilerini inceleyen çalışmalara ulaşılmıştır.…”

“…Polak ve arkadaşları katot tarafının saf oksijen ile beslendiğinde katot stokiyometrik oranının saf oksijen kullanılmadığı haline göre nasıl değişeceği üzerine deneysel bir çalışma yürütmüşlerdir. Çalışma sonucunda katot tarafında saf oksijen kullanılmasıyla, yığın verimliliği aynı kalmak koşuluyla, katot stokiyometrik oranı 1,25 değerine düşmüştür [11].…”