Radiative heat transfer analysis

Damm D.L. and Fedorov A.G., 2004. Spectral radiative heat transfer analysis of the planar SOFC. In Proceedings of the ASMEIMECE, Anaheim, CA, November 13-19, 2004. Paper No. IMECE2004-60142. 

D. L. Damm and A. G. Fedorov. Spectral Radiative Heat Transfer Analysis of the Planar SOFC. ASME 2, (2005) 258-262. 

A window consisting of a single piece of clear glass can also he treated with R-value analysis. As with the wall, there is convective and radiative heat transfer at the two surfaces and conductive heat transfer through the glass. The resistance of the window is due to the two surface resistances and to the conductive resistance of the glass, For typical window glass, R = 0.003 (W/ni -°C)" (0.02 (Btu/h-ft -°F) ) so the total resistance of the window is = (0.12 + 0.003 + 0.04) (W/m -- C) ... 

Vedamuthy, V. N., and Sastri, V. M. K., An Analysis of the Conductive and Radiative Heat Transfer to Walls of Fluidized Combustors, Intern. J. Heat Mass Transf, 17(1) 1-9 (1074)... 

The detailed analysis of radiative heat transfer can easily become extremely complicated when transmission, reflection and complex geometries are taken into account.4 An important conclusion which may be reached is that the heat flux corresponding to the surrounding black body is the maximum radiative heat flux that may be achieved, i.e. for Fn = 1 and s = 1 ... 

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. 

Radiative heat transfer is not negligible for liquids with high boiling points or for opaque droplets with highly luminous flames. The analysis requires modification for these systems (see Section 3.3.6). 

Abstract. This chapter introduces crystallization process of multicrystalline silicon by using a directional solidification method. Numerical analysis, which includes convective, conductive, and radiative heat transfers in the furnace is also introduced. Moreover, a model of impurity segregation is included in this chapter. A new model for three-dimensional (3D) global simulation of heat transfer in a unidirectional solidification furnace with square crucibles was also introduced. 

J. T. Farmer, Improved Algorithms for Monte Carlo Analysis of Radiative Heat Transfer in Complex Participating Media, Ph.D. Dissertation, University of Texas, Austin, August, 1995. 

K. C. Tang and M. Q. Brewster, -Distribution Analysis of Gas Radiation with Non-gray, Emitting, Absorbing, and Anisotropic Scattering Particles, in S. T. Thynell et al. (eds.), Developments in Radiative Heat Transfer, ASME-HTD-vol. 203, pp. 311-320,1992. 

Items 1-4 determine the degree to which the radiation source and material load are thermally coupled and can be addressed with the heat transfer analysis methods outlined in Chap. 7 of this handbook. Items 5 and 6 may be quantified with an analysis, which takes into account the multimode heat transfer effects discussed elsewhere in this handbook. Because of the nonlinear nature of radiative heat transfer, few correlations exist that can be applied to relevant materials processing situations. 

The thermal system model for radiant-tube continuous furnace involves integration of the mathematical models of the furnace enclosure, the radiant tube, and the load. The furnace enclosure model calculates the heat transfer in the furnace, the furnace gas, and the refractory walls. The radiosity-based zonal method of analysis [159] is used to predict radiation heat exchange in the furnace enclosure. The radiant-tube model simulates the turbulent transport processes, the combustion of fuel and air, and the convective and radiative heat transfer from the combustion products to the tube wall in order to calculate the local radiant-tube wall and gas temperatures [192], Integration of the furnace-enclosure model and the radiant-tube model is achieved using the radiosity method [159]. Only the load model is outlined here. 

Khan, Y.U., Lawson, DA., Tncker, R. J. Analysis of Radiative Heat Transfer in Ceramic-Lined and Ceramic-Coated Fnmaces, pp. 21,26. Institute of Energy journal, March 1998. 

One cautionary note should be kept in mind when using Eqs. (42)-(45) and (71) to calculate radiative heat transfer in FFB. The bed s absolute temperature 1), is normally assumed to be uniform across the bed and is used as the source or sink temperature in Eqs. (42) and (43). This assumption may be inappropriate in those cases in which a dense aimular region of particles shields the FFB wall from the bulk bed. In sueh situations, it is the average temperature of the particles in the annular layer that should be taken as the source/ sink temperature for ealeulation of radiant heat flux to/from the wall. This requires a mass and heat balance analysis for the material flowing in the annulus, and the reader is referred to Chapter 19 for necessary hydrodynamic models. 

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. 

A model of particular importance for the present analysis is concerned with the heatup and possible melting of the upper in-vessd structures (upper shroud head, standpipes, steam separators, and steam dryers). The shroud-head/steam-separator assembly consists of a domed base on top of whidi is welded an array of standpipes with a multi-stage steam separator located on the top of each standpipe. The entire assembly, made of stainless steel, rests on the top-guide grid and forms a cover for the core outlet plenum region. The steam dryer assanbly is mounted in the reactor vessel above the shroud-head/steam-separator assembly. Since, in tihe case of an accident, the upper shroud head may be directiy exposed to a high-temperature core, the combined effects of radiation from the core and convective/radiative heat transfer from the hot steam/gas mixture in the upper plenum, may increase the shroud temperature to failure point. When the weakened shroud head cannot support the mass above it, the upper structures may coUapse onto the core (except for the steam dryer which has a separate support system). The molten steel from these structures may penetrate the hot and partially molten core and flow into the lower plenum and, following lower head failure, into the containment. 

At fuel manifold inlets, gaseous species concentrations are specified as equilibrium compositions of the town gas reformate at 650°C. Steam-to-carbon ratio is kept as 3.06 for this particular steady-state analysis. Both fuel and air gas manifold inlet conditions are summarized in Table 9.5. Mixed convective and radiative heat transfer boundary conditions are applied to the side surfaces of the stack to accurately model the heat exchange with the balance of plant components. Top and bottom surfaces, on the other hand, are assigned with... 

Chen, J. C., Chen, K. L., Analysis of Simultaneous Radiative and Conductive Heat Transfer in Fluidized Beds, Chem. Eng. Commun., 9 255-271 (1981)... 

In a series of papers, Derby and Brown (144, 149-152) developed a detailed TCM that included the calculation of the temperature field in the melt, crystal, and crucible the location of the melt-crystal and melt-ambient surfaces and the crystal shape. The analysis is based on a finite-ele-ment-Newton method, which has been described in detail (152). The heat-transfer model included conduction in each of the phases and an idealized model for radiation from the crystal, melt, and crucible surfaces without a systematic calculation of view factors and difiuse-gray radiative exchange (153). 

If the fluid is transparent, qA + qf0 + qwQ must be determined from a combined radiative-conductive analysis—see, for example, Hollands et al. [143]. Such an analysis is beyond the scope of this chapter, whose function is to report the additional heat transfer associated with free convective motion. This motion usually alters the temperature distribution in the wall... 

S. H. Chan, Numerical Methods for Multidimensional Radiative Transfer Analysis in Participating Media, Annual Review of Numerical Fluid Mechanics and Heat Transfer, vol. 1, Hemisphere, New York, pp. 305-350,1987. 

Chen JC, Chen KL. Analysis of simultaneous radiative and conductive heat transfer in fluidized beds. Chem Eng Commun 9 255 271, 1981. 

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