Thermodynamics HW Solutions 374

Thermodynamics HW Solutions 374 - Chapter 4 Transient Heat...

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
Chapter 4 Transient Heat Conduction 4-106 A curing kiln is heated by injecting steam into it and raising its inner surface temperature to a specified value. It is to be determined whether the temperature at the outer surfaces of the kiln changes during the curing period. Assumptions 1 The temperature in the wall is affected by the thermal conditions at inner surfaces only and the convection heat transfer coefficient inside is very large. Therefore, the wall can be considered to be a semi-infinite medium with a specified surface temperature of 45 ° C. 2 The thermal properties of the concrete wall are constant. Properties The thermal properties of the concrete wall are given to be k = 0.9 W/m. ° C and α = 0.23 × 10 -5 m 2 /s. Analysis We determine the temperature at a depth of x = 0.3 m in 3 h using the analytical solution, = t x erfc T T T t x T i s i α 2 ) , ( 2 ° C 42 ° C 30 cm Kiln wall x 0 Substituting, C 9.1 ° = = = × × = ) , ( 1782
Background image of page 1
This is the end of the preview. Sign up to access the rest of the document.
Ask a homework question - tutors are online