Two aisi 304 stainless steel plates 10 mm thick are subjected to a contact pressure of 1 bar under vacuum conditions for which there is an overall temperature drop of 110°c across the plates. (a) what is the heat flux through the plates? (b) what is the temperature drop across the contact plane? use r"t, c=15 x 10-4 m2·k/w and evaluate the properties of stainless steel at 400 k.

Explanation:

First calculate

(a)

R₁=

  R₁= 0.01/16.6

   =6.024*10⁻⁴ m² . K/W

  R₁=R₂=6.024*10⁻⁴ m² . K/W

The contact thermal resistance of AISI 304 stainless steel

  = 15*10⁻⁴ m² . K/W

  R=R₁+R₂+

  R=6.024*10⁻⁴+15*10⁻⁴ +6.024*10⁻⁴

   R=27.048 *10⁻⁴ m² . K/W

Calculate the rate of heat transfer

q=ΔT/R

  =110/(27.048 *10⁻⁴)

  q= 40668.44 W/m²

(b)

       Calculate the difference of temperature across the plate

        ΔT=110*

        ΔT=61.002 K

see earlier