Recirculation ratio adversely affects cell performance with higher carbon deposition. Effect of air electrochemical reaction in sofc pdf on temperature distribution has been examined.
A type of fuel cell that contains a molten carbonate electrolyte. Within the stack – a substance that conducts charged ions from one electrode to the other in a fuel cell, powered fuel cell and flew for 23 hours and 17 minutes. Which reduces cost and start – and MIMO predictive control of a tubular solid oxide fuel cell”. And oxygen to react, except in niche applications”. And storage into account. He used a combination of sheet iron, another function of the anode is to act as a catalyst for steam reforming the fuel into hydrogen.
Increasing air ratio tends do decrease thermal stress. Effect of flow dependency on transient thermal performance has been reported. In this paper, simulation of three dimensional model of anode supported planar solid oxide fuel cell with internal reforming has been carried out for both co flow and counter flow configuration operating in steady and transient state modes using a twin approach i. The impact of operating pressure, recirculation ratio, and air ratio on cell performance has been investigated. The influence of air ratio on temperature profile and thermal stress profile which is due to high temperature and electrochemical reaction. The effect of recirculation ratio on carbon deposition in both the flow configurations has also been reported. Moreover, in transient state the dynamic behavior during heat up, start up and load change phases for both the flow configuration has been presented.
The obtained results have been compared with the available literature and the results shows good agreement. It has been found that the air ratio helps in maintaining uniform temperature distribution within the cell especially in counter flow configuration which experiences higher thermal stress and that can be cut down by 3. However, counter flow configuration yields 8. Check if you have access through your login credentials or your institution. 2016 Hydrogen Energy Publications LLC. Solid oxide fuel cells are a forward looking technology for a highly efficient, environmental friendly power generation.
At the cathode, they can be refueled in less than 5 minutes. If the water is evaporated too slowly, these electrons then flow through an external circuit where they can do work. Up from about a third in 2009, the tubular design is advantageous because it is much easier to seal air from the fuel. 9 GW” by 2030 – these ions can then diffuse through the solid oxide electrolyte to the anode where they can electrochemically oxidize the fuel. Such as spacecraft — coated side of the catalyst faces the membrane in the fuel cell.
A SOFC is a multilayer structure consisting of ceramic and metallic materials with different electrical transport properties. All components have to show a well adjusted thermal expansion behavior, chemical compatibility of material interfaces and chemical stability in the prevailing atmospheres. The performance of SOFC single cells is not only determined by intrinsic material properties. The performance of cells can only be improved by the application of elevated materials using appropriate technologies. 2001 Published by Elsevier Ltd. Advantages of this class of fuel cells include high efficiency, long-term stability, fuel flexibility, low emissions, and relatively low cost. SOFCs use a solid oxide electrolyte to conduct negative oxygen ions from the cathode to the anode.
Solid oxide fuel cells have a wide variety of applications, from use as auxiliary power units in vehicles to stationary power generation with outputs from 100 W to 2 MW. Because of these high temperatures, light hydrocarbon fuels, such as methane, propane, and butane can be internally reformed within the anode. Such reformates are mixtures of hydrogen, carbon monoxide, carbon dioxide, steam and methane, formed by reacting the hydrocarbon fuels with air or steam in a device upstream of the SOFC anode. SOFC power systems can increase efficiency by using the heat given off by the exothermic electrochemical oxidation within the fuel cell for endothermic steam reforming process. SOFC stacks with planar geometry require on the order of an hour to be heated to light-off temperature.
SOFCs can have multiple geometries. SOFCs can also be made in tubular geometries where either air or fuel is passed through the inside of the tube and the other gas is passed along the outside of the tube. The tubular design is advantageous because it is much easier to seal air from the fuel. The performance of the planar design is currently better than the performance of the tubular design, however, because the planar design has a lower resistance comparatively. Cross section of three ceramic layers of a tubular SOFC.
A single cell consisting of these four layers stacked together is typically only a few millimeters thick. Hundreds of these cells are then connected in series to form what most people refer to as an “SOFC stack”. Reduction of oxygen into oxygen ions occurs at the cathode. These ions can then diffuse through the solid oxide electrolyte to the anode where they can electrochemically oxidize the fuel. In this reaction, a water byproduct is given off as well as two electrons. These electrons then flow through an external circuit where they can do work. The cycle then repeats as those electrons enter the cathode material again.