Browsing by Author "Yan, Yi-Yie"

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Improvement of CO tolerance of proton exchange membrane fuel cell (PEMFC) by an air-bleeding technique
(2005)
Chung, Chen-Chung
;
Chen, Chiun-Hsun
;
Lin, Hsiang-Hui
;
Yan, Yi-Yie
;
機械工程學系
The investigation studies improving PEMFC carbon monoxide by a periodic air dosing. The carbon monoxide in the fuel gas leads to a significant loss in power density due to CO poisoning in the anode. The method involves bleeding air into the anode fuel stream (H-2-CO), which contains CO in various concentrations (20, 52.7, 100 ppm). In the transient CO poisoning test, air-bleeding is performed for four different periodic air dosing and cell voltage is fixed at 0.6 V. The result of a dosing of air during 10 sec in intervals of 10 sec is similar to that of continuous air-bleeding except 100 ppm CO. The CO tolerance of the fuel cell and cell performance recovery from poisoning can be improved by air-bleeding.
Improvement of CO tolerance of proton exchange membrane fuel cell by an air-bleeding technique
(2008-02-01)
Chen, Chiun-Hsun
;
Chung, Chen-Chung
;
Lin, Hsiang-Hui
;
Yan, Yi-Yie
;
機械工程學系
This study investigates the improvement of proton exchange membrane fuel cell (PEMFC) carbon monoxide by periodic air dosing. The carbon monoxide in the fuel gas leads to a significant loss in power. density due to CO poisoning in the anode. The method involves bleeding air into the anode fuel stream (H(2)-CO), which contains CO in various concentrations (20 ppm, 52.7 ppm, and 100 ppm). In the transient CO poisoning test, air bleeding is performed for four different periodic air dosing and cell voltage is fixed at 0.6 V. The result of a dosing of air for 10 s in intervals of 10 s is similar to that of continuous air bleeding except for 100 ppm CO. The CO tolerance of the fuel cell and cell performance recovery from poisoning can be improved by air bleeding.
Investigation of cell operation conditions for co tolerance improvement of PEMFC
(2007-12-01)
Chung, Chen-Chung
;
Chen, Chiun-Hsun
;
Weng, Der-Cheng
;
Yan, Yi-Yie
;
Lin, Hsiang-Hui
The investigation is to experimentally study the transient CO poisoning test with different cell operation conditions. One is fixing the cell voltage and the other is fixing the current density. In the former condition, the voltages are fixed at 0.5, 0.6, 0.7V, respectively, whereas the current densities are fixed at 600, 1000, 1200mA/cm(2), respectively, in the latter one. In the transient poisoning test, the cell performance will be declined with time. The poisoned polarization curves are determined as soon as the performance subjected to CO poisoning reaches a steady state. Then, it will determine which one has a better performance in CO poisoning test and find out the difference between these two methods. With fixed cell voltage to perform transient CO poisoning test, it indicates that changing cell voltage cannot transform the stable poisoned polarization behaviors, whereas with fixed current density, it can get a better recovery performance at a fixed CO concentration (52.7ppm).
Transient evolution of carbon monoxide poisoning effect of PBI membrane fuel cells
(2007-07-10)
Wang, Chien-Ping
;
Chu, Hsin-Sen
;
Yan, Yi-Yie
;
Hsueh, Kan-Lin
;
機械工程學系
High temperature poly benzimidazole membrane fuel cells are the focus of attention due to high CO tolerance and overcoming water managements. This paper develops a transient. one-dimensional mathematical model to predict CO tolerance, and validates it with experiments. Experimental results are measured at different temperatures. Fuel cell performance degradations with time are also measured under various fuel compositions. Transient evolutions of current density, H-2 coverage, CO coverage, and ionic potential are shown during the CO poisoning process. The theoretical results show that hydrogen coverage decreases with time, reducing hydrogen oxidation reactions and dropping ionic potential loss. The effects of temperature. CO contents. and H-2 dilutions on fuel cell performance and the time to reach steady t(ss) are all investigated. Predictions of fuel cell current density degradation also show good agreement with experimental results. (c) 2007 Elsevier B.V. All rights reserved.