Monolith radiative transfer

Solid temperature may be above 1000 K, and thus, radiative heat transfer cannot be neglected. Lee and Aris (1977) focused on the wall-to-wall radiation problem. They showed that this heat transfer process is responsible for lower conversion due to lower solid temperature and smaller temperature gradients, and that the maximum solid temperature may be about 100 K below that calculated with a model ignoring radiative heat transfer. Unfortunately, as mentioned by these authors, the mathematics are too complex to be incorporated in realistic models. Most sophisticated converter models neglect the wall to wall radiative heat transfer. Chen et al. (1988, 1989) accounted for gas-solid radiative transfer toward the surrounding medium. The surface temperature of the converter must be at least 1000 K for the radiation contribution to become important. Ryan et al. (1991) considered radiation from the front and aft faces of the monolith, and concluded that this process is not important. 

Note that, despite the typically high operating temperatures of fuel cells, radiative heat transfer was neglected. Lee and Aris (16) have discussed such effects in parallel-channel monoliths. The importance of radiative transport depends on the emissivity of the surface for the low (about 0.1) emissivity of Pt-coated catalyst-electrodes, their analysis suggests that radiative effects can be neglected. 

Burt A.C., Celik I.B., Gemmen R.S., Smirnov A.V., 2003. Influence of radiative heat transfer on variation of cell voltage within a stack. ]nProceedngs of the 1st International Conference on Fuel Cell Science, Engineering and Technology, Rochester, NY, April 21-23, 2003. Murthy S., Fedorov G, 2003. Radiation heat transfer analysis of the monolith type solid oxide fuel cell. Journal of Power Sources 124(2), 453-458. 

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