Sensible heat transfer Inside tubes

Sensible heat transfer in most applications involves forced convection inside tubes or ducts or forced convection over exterior surfaces. 

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Evaluate sensible heat transfer inside tubes as previously oudined for in-tube transfer. Determine the area required. 

For horizontal tubeside condensers, no good methods are available for predicting heat transfer coefficients when appreciable subcooling of the condensate is required. A conservative approach is to calculate a superficial mass velocity assuming the condensate filis the entire tube and use the equations presented previousiy for a singie phase sensible heat transfer inside tubes... 

The condensing temperature of the steam is 300°F. The process into which the heat is transferred is at a constant temperature of 20O°F. The overall heat transfer coefficient is 300 Btu/h °F ft. The reboiler has S09 tubes that arc 10 feet long and 1 inch inside diameter. The steam and condensate are inside the tubes. The density of the condensate is 62,4 Ib ft and the latent heat of condensation of the steam is 900 Btu/lb . Neglect any sensible heat transfer. 

Figure 10-103. Kern correlation for natural circulation boiling and sensible film coefficients—outside and inside tubes. (Used by permission Kern, D.Q. Process Heat Transfer, Ed., 1950. McGraw-Hill Book Company. All rights reserved.)...

HEAT-TRANSFER COEFFICIENTS FOR FLUIDS FLOWING INSIDE TUBES FORCED CONVECTION, SENSIBLE HEAT 7.26... 

Heat transport with phase change such as in boiling or condensation is an efficient method to transfer heat because latent heat per unit mass is very large compared to the sensible heat. For single component fluid, the interface temperature difference involved for heat transfer in evaporation and condensation is relatively small. However, when more than one component is present in a system the temperature difference can be higher. An example is condensation of vapors in the presence of noncondensable gases. The two-phase heat transfer relevant to reactors includes pool boiling, evaporation in a vertical channels, and condensation inside or outside the tubes. 

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