Air at 20ºc with a convection heat transfer coefficient of 25 w/m2·k blows over a horizontal steel hot plate (k = 43 w/m·k). the surface area of the plate is 0.38 m2 with a thickness of 2 cm. the plate surface is maintained at a constant temperature of ts = 350°c, and the plate loses 300 w from its surface by radiation. calculate the inside plate temperature (ti). (round your answer up to 3 decimal places.)

Question

Jazlyn Wolf

Physics

16 January, 21:39

Air at 20ºc with a convection heat transfer coefficient of 25 w/m2·k blows over a horizontal steel hot plate (k = 43 w/m·k). the surface area of the plate is 0.38 m2 with a thickness of 2 cm. the plate surface is maintained at a constant temperature of ts = 350°c, and the plate loses 300 w from its surface by radiation. calculate the inside plate temperature (ti). (round your answer up to 3 decimal places.)

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Answers (1)

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Esperanza Blackburn · Answer 1

Heat transfer due to convection = Heat transfer due to conduction

Heat transfer due to convection, Q = h_c*AdT

Where,

h_c = 25 W/m^2K

A = 0.38 m^2

dT = 350 - 20 = 330 K

Substituting;

Q = 25*0.38*330 = 3135 W

Heat transfer through the hot steel plate, Q = (k/s) AdT

k = 43 W/m. k

s = 2 cm = 0.02 m

dT = ti - 350

Therefore,

3135 = (43/0.02) * 0.38 * (ti-3500

ti-350 = 3135/[ (43/0.02) * 0.38] = 3.837

ti = 3.837+350 = 353.837°