scholarly journals Wide range constant current power supply. [10/sup -10/ to 10/sup -2/ A; for measuring current--voltage characteristics of fuel cell electrodes]

1978 ◽  
Author(s):  
M.F. Weber
Energies ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 3073
Author(s):  
Krzysztof Górecki ◽  
Małgorzata Górecka ◽  
Paweł Górecki

This paper proposes a model of an electrolyser in the form of a subcircuit dedicated for SPICE. It takes into account both the electric static and dynamic properties of the considered device and is devoted to the optimisation of the parameters of the signal feeding this electrolyser, making it possible to obtain a high productivity and efficiency of the electrolysis process. Parameter values the describing current-voltage characteristics of the electrolyser take into account the influence of the concentration of the potassium hydroxide (KOH) solution. A detailed description of the structure and all the components of this model is included in the paper. The correctness of the elaborated model is verified experimentally in a wide range of changes in the value of the feeding current and concentration of the KOH solution. Some computations illustrating the influence of the amplitude, average value, duty factor, and frequency of feeding current on the productivity and efficiency of the electrolysis process are performed. On the basis of the obtained results of the investigations, some recommendations for the operating conditions of electrolysers are formulated.


Author(s):  
М.И. Шишкин ◽  
М.В. Гавриков ◽  
И.Т. Ягудин ◽  
А.Г. Роках

In the lead sulfide nanoparticles-based layers deposited from alcohol suspensions, analysis of the current-voltage characteristics made it possible to establish the basic mechanism of electron transport. Previously, using optical measurements in the range of 3500 nm, it was shown that the organic component in such layers was practically absent. When exposed to wide range radiation corresponding to the “transparency window” of the atmosphere of 8000–14000 nm, a current change in PbS nanodust was detected, where, as previously shown, absorption on free charge carriers can occur.


Author(s):  
Susanta K. Das ◽  
Antonio Reis ◽  
Etim U. Ubong ◽  
K. Joel Berry

In this paper, we experimentally studied an air breathing high temperature PEM fuel cell at steady operating conditions to investigate the effects of CO poisoning at different temperatures ranges between 120°C∼180°C. The effects of changes in temperatures with different amount of CO poisoning on the current-voltage characteristics of the fuel cell are investigated. Experimental data of this type would be very useful to develop design parameters of fuel processor based on reformate hydrocarbons. The high CO tolerance of high temperature PEM fuel cells makes it possible to use the reformate gas directly from the reformer without further CO removal. Here we considered the fact that a steam reformer is a consumer of heat and water, and fuel cell stacks are a producer of heat and water. Thus, integration of the fuel cell stack and the reformer is expected to improve the system performance. The results obtained from the experiments showed variations in current-voltage characteristics at different temperatures with different CO poisoning rates. The results will help to understand the overall system performance development strategy of high temperature PEM fuel cell in terms of current-voltage characteristics, when fed with on-site reformate hydrogen gas with variable CO concentrations.


Author(s):  
Susanta K. Das ◽  
K. Joel Berry

Compact and efficient fuel reforming system design is a major challenge because of strict requirements of efficient heat distribution on both the reforming and combustion side. As an alternative to traditional packed bed tubular reformers, catalytic flat plate fuel reformer offers better heat integration by combining the combustion reaction on one side and reforming reaction on the other side. In this study, with the help of a two-dimensional computational fluid dynamics (CFD) model, a catalytic flat plate fuel reformer is built and investigated its performance experimentally. The CFD model simulation results help to capture the effect of design parameters such as catalyst layer thickness, reaction rates, inlet temperature and velocity, and channel height. The CFD model study results also help to design and built the actual reformer in such a way that eliminate the limitations or uncertainties of heat and mass transfer coefficients. In our study, we experimentally evaluated the catalytic flat plate fuel reformer performance using natural gas. The effect of reformate gas on the current-voltage characteristics of a 5kW high temperature PEM fuel cell (HTPEMFC) stack is investigated extensively. The results shows that the overall system performance increases in terms of current-voltage characteristics of HTPEMFC while fed with reformate directly from the catalytic flat plate reformer.


2016 ◽  
Vol 685 ◽  
pp. 776-780
Author(s):  
Andrey A. Solovyev ◽  
Anastasya N. Kovalchuk ◽  
Igor V. Ionov ◽  
S.V. Rabotkin ◽  
Anna V. Shipilova ◽  
...  

Reducing the operating temperature of solid oxide fuel cells (SOFCs) from 800-1000°C is one of the main SOFC research goals. It can be achieved by lowering the thickness of an electrolyte (ZrO2:Y2O3 (YSZ) is widely used as electrolyte material). On the other hand the problem can be solved by using of another electrolyte material with high ionic conductivity at intermediate temperatures. Therefore the present study deals with magnetron sputtering of ceria gadolinium oxide (CGO), which has a higher conductivity compared to YSZ. The microstructure of CGO layers deposited on porous NiO/YSZ substrates by reactive magnetron sputtering of Ce:Gd cathode is investigated. Current voltage characteristics (CVC) of a fuel cell with NiO/YSZ anode, CGO electrolyte and LSCF/CGO cathode were obtained. It was shown that the power density of a fuel cell with CGO electrolyte weakly depends on the operating temperature in the range of 650-750°C in contradistinction to YSZ electrolyte, and is about 600-650 mW/cm2.


1988 ◽  
Vol 42 (4) ◽  
pp. 576-583 ◽  
Author(s):  
Suzanne Tanguay ◽  
Richard Sacks

Current-voltage characteristics and spatially resolved atomic emission data are used to describe the basic operation of a magnetron glow discharge plasma device. The low-pressure glow discharge lamp uses a center-post cathode and a concentric ring-shaped anode. A coaxial magnetic field of a few hundred Gauss is used to achieve magnetron operation where plasma electrons are trapped in closed paths which are concentric with the electrode structure. This results in dramatic changes in the radiative and electrical properties of the device. With constant current, lamp operating voltage may be reduced by more than a factor of two when the magnetic field is present. The effects of filler gas pressure and magnetic field strength on the current-voltage characteristics are presented. The presence of the magnetic field results in a radial contraction of the plasma. This contraction increases with increasing field strength and with decreasing pressure. Ion lines from the Ar filler gas are more affected by the field than are neutral-atom lines from the cathode material.


2017 ◽  
Vol 424 ◽  
pp. 239-244 ◽  
Author(s):  
E.O. Popov ◽  
A.G. Kolosko ◽  
S.V. Filippov ◽  
P.A. Romanov ◽  
E.I. Terukov ◽  
...  

Author(s):  
Susanta K. Das

In this study, we experimentally evaluated our newly designed high temperature PEM fuel cell (HTPEMFC) prototype performance at different operating conditions. In particular, we investigated the effects of operating temperature, pressure, air stoichiometry and CO poisoning in the anode fuel stream on the current-voltage characteristics of the HTPEMFC prototype. Experimental results obtained from the single HTPEM fuel cell show that the performance is quite steady with high CO-level reformate at high operating temperature which makes it possible to feed the reformate gas directly from the reformer to the stack without further CO removal. In order to develop design parameters for fuel reformer, experimental data of this type would be very useful. The results obtained from this study showed significant variations in current-voltage characteristics of HTPEMFC at different temperatures with different CO poisoning rates. The results are promising to understand the overall system performance development strategy of HTPEMFC in terms of current-voltage characteristics while fed with reformate with different CO ratios in the anode fuel stream.


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