Analysis for the Effect of Inverter Ripple Current on Fuel Cell Operating Condition

2001 ◽  
Author(s):  
Randall S. Gemmen
Keyword(s):  
Boundary Condition ◽  
Fuel Cell ◽  
Mass Transport ◽  
Transient Behavior ◽  
Mechanical State ◽  
Dimensional Model ◽  
One Dimensional ◽  
Fuel Cell Stack ◽  
A Cell ◽  
The Impact

Abstract The effect of inverter ripple current on fuel cell stack performance and stack lifetime remains uncertain. This paper provides a first attempt to examine the impact of inverter load dynamics on the fuel cell. Since reactant utilization is known to impact the mechanical state of a fuel cell, it is suggested that the varying reactant conditions surrounding the cell govern, at least in part, the lifetime of the cells. This paper investigates these conditions through the use of a dynamic model for the bulk conditions within the stack, as well as a one-dimensional model for the detailed mass transport occurring within the electrode of a cell. These two independent modeling approaches help to verify their respective numerical procedures. In this work, the inverter load is imposed as a boundary condition to the models. Results show the transient behavior of the reactant concentrations within the stack, and of the mass diffusion within the electrode under inverter loads with frequencies between 30 Hz and 1250 Hz.

Analysis for the Effect of Inverter Ripple Current on Fuel Cell Operating Condition

2003 ◽  
Vol 125 (3) ◽  
pp. 576-585 ◽  
Author(s):  
Randall S. Gemmen
Keyword(s):  
Boundary Condition ◽  
Fuel Cell ◽  
Mass Transport ◽  
Transient Behavior ◽  
Dimensional Model ◽  
One Dimensional ◽  
Fuel Cell Stack ◽  
A Cell ◽  
The Impact ◽  
Mechanical Nature

The effect of inverter ripple current on fuel cell stack performance and stack lifetime remains uncertain. This paper provides a first attempt to examine the impact of inverter load dynamics on the fuel cell. Since reactant utilization is known to impact the mechanical nature of a fuel cell, it is suggested that the varying reactant conditions surrounding the cell govern, at least in part, the lifetime of the cells. This paper investigates these conditions through the use of a dynamic model for the bulk conditions within the stack, as well as a one-dimensional model for the detailed mass transport occurring within the electrode of a cell. These two independent modeling approaches are used to verify their respective numerical procedures. In this work, the inverter load is imposed as a boundary condition to the models. Results show the transient behavior of the reactant concentrations within the stack, and of the mass diffusion within the electrode under inverter loads with frequencies between 30 Hz and 1250 Hz.

Assessing the Impact of Inverter Current-Ripple on SOFC Performance

2003 ◽  
Author(s):  
Randall S. Gemmen ◽  
Parviz Famouri ◽  
Christopher Johnson
Keyword(s):  
Fuel Cell ◽  
Transient Model ◽  
One Dimensional ◽  
Fuel Cell Stack ◽  
First Order ◽  
A Cell ◽  
Current Loading ◽  
Dc Current ◽  
The Impact ◽  
Current Ripple

The effect of inverter ripple current on fuel cell stack performance is not well understood. This paper provides a first-order examination of the impact of inverter load dynamics on SOFC fuel cell operation. Previous work using steady-state fuel cell loading has shown that DC-current loading itself results in degradation of the fuel cell, albeit in ways yet to be fully understood. This result suggests that the varying reactant conditions that result from ripple may modify degradation processes, and, therefore, the lifetime of the cells. This paper investigates these conditions through the use of a dynamic one-dimensional model for the detailed mass transport occurring within the electrode of a cell. In this work, the inverter load is imposed as a boundary condition to the transient model. Results show the behavior of the reactant concentrations within the stack electrodes under inverter loads with frequencies between 60 Hz and 1250 Hz. It is concluded that a ripple factor of less than 6% be used to ensure minor impact to the conditions at the electrode-electrolyte interface.

scholarly journals Overcoming the Challenges for a Mass Manufacturing Machine for the Assembly of PEMFC Stacks

Machines ◽  
2019 ◽  
Vol 7 (4) ◽  
pp. 66 ◽  
Author(s):  
Porstmann ◽  
Wannemacher ◽  
Richter
Keyword(s):  
Fuel Cell ◽  
Economies Of Scale ◽  
Polymer Electrolyte Membrane ◽  
Cell System ◽  
Active Components ◽  
Fuel Cell Stack ◽  
Electrolyte Membrane ◽  
Modular Concept ◽  
A Cell ◽  
Manufacturing Machine

One of the major obstacles standing in the way of a break-through in fuel cell technology is its relatively high costs compared to well established fossil-based technologies. The reasons for these high costs predominantly lie in the use of non-standardized components, complex system components, and non-automated production of fuel cells. This problem can be identified at multiple levels, for example, the electrochemically active components of the fuel cell stack, peripheral components of the fuel cell system, and eventually on the level of stack and system assembly. This article focused on the industrialization of polymer electrolyte membrane fuel cell (PEMFC) stack components and assembly. To achieve this, the first step is the formulation of the requirement specifications for the automated PEMFC stack production. The developed mass manufacturing machine (MMM) enables a reduction of the assembly time of a cell fuel cell stack to 15 minutes. Furthermore the targeted automation level is theoretically capable of producing up to 10,000 fuel cell stacks per year. This will result in a ~50% stack cost reduction through economies of scale and increased automation. The modular concept is scalable to meet increasing future demand which is essential for the market ramp-up and success of this technology.

Modelling the impact of creep on the probability of failure of a solid oxide fuel cell stack

2014 ◽  
Vol 34 (11) ◽  
pp. 2695-2704 ◽  
Author(s):  
Fabio Greco ◽  
Henrik Lund Frandsen ◽  
Arata Nakajo ◽  
Mads Find Madsen ◽  
Jan Van herle
Keyword(s):  
Fuel Cell ◽  
Solid Oxide Fuel Cell ◽  
Probability Of Failure ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Fuel Cell Stack ◽  
The Impact

scholarly journals Thermal Analysis of a Double Glazed Window with a Between-Panes Pleated Blind

2021 ◽  
Author(s):  
Rasesh Dalal
Keyword(s):  
Fluid Dynamics ◽  
Thermal Analysis ◽  
Thermal Performance ◽  
Two Dimensional ◽  
Dimensional Model ◽  
Number Range ◽  
One Dimensional ◽  
U Value ◽  
Shading Devices ◽  
The Impact

A simplified two-dimensional numerical model of a window with a between-panes pleated blind has been developed using commercial computational fluid dynamics software. Knowledge of the effect of blinds on the free convection is important for understanding and predicting the impact of shading devices on the overall thermal performance of a window. Numerical results have been obtained for three fill gases (air, argon and krypton) and several blind geometries over the Rayleigh number range 10³ [less than or equal to]Ra[less than or equal to]10[to the exponent of 5]. The results show that pleated blinds can have a strong effect on window thermal performance. In addition, it has been shown that the data from a convection-only model can be combined with a simplified one-dimensional model to estimate the overall U-value of the enclosure. Using this procedure, the convection data can be applied to a window/blind assembly with arbitrary radiation parameters.

Hardware-Based Simulation of a Fuel Cell Turbine Hybrid Response to Imposed Fuel Cell Load Transients

2006 ◽  
Author(s):  
Thomas P. Smith ◽  
Comas L. Haynes ◽  
William J. Wepfer ◽  
David Tucker ◽  
Eric A. Liese
Keyword(s):  
Fuel Cell ◽  
Solid Oxide Fuel Cell ◽  
Gas Turbine ◽  
Pressure Vessels ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Electrical Load ◽  
Fuel Cell Stack ◽  
Thermal Transients ◽  
The Impact

Electrical load transients imposed on the cell stack of a solid oxide fuel cell/gas turbine hybrid power system are studied using the Hybrid Performance (HyPer) project. The hardware simulation facility is located at the U.S. Department of Energy, National Energy Technology Laboratory (NETL). A computational fuel cell model capable of operating in real time is integrated with operating gas turbine hardware. The thermal output of a modeled 350 kW solid oxide fuel cell stack is replicated in the facility by a natural gas fired burner in a direct fired hybrid configuration. Pressure vessels are used to represent a fuel cell stack's cathode flow and post combustion volume and flow impedance. This hardware is used to simulate the fuel cell stack and is incorporated with a modified turbine, compressor, and 120 kW generator on a single shaft. For this study, a simulation was started with a simulated current demand of 307 A on the fuel cell at approximately 0.75 V and an actual 45 kW electrical load on the gas turbine. An open loop response, allowing the turbine rotational speed to respond to thermal transients, was successfully evaluated for a 5% current reduction on the fuel cell followed by a 5% current increase. The impact of the fuel cell load change on system process variables is presented. The test results demonstrate the capabilities of the hardware-in-the-loop simulation approach in evaluating hybrid fuel cell turbine dynamics and performance.

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