Question

**4-23** After heat treatment, the 2-cm thick metal
plates (k = 180 W/m·K, ρ = 2800 kg/m3, and cp

= 880 J/kg·K) are conveyed through a cooling chamber with a length of 10 m. The plates enter the cooling

chamber at an initial temperature of 500°C. The cooling chamber maintains a temperature of 10°C, and

the convection heat transfer coefficient is given as a function of the air velocity blowing over the plates h

= 33V0.8, where h is in W/m2·K and V is in m/s. To prevent any incident of thermal burn, it is necessary

for the plates to exit the cooling chamber at a temperature below 50°C. In designing the cooling process to

meet this safety criteria, use excel to investigate the effect of the air velocity on the

temperature of the plates at the exit of the cooling chamber. Let the air velocity vary from 0 to 40 m/s, and

plot the temperatures of the plates exiting the cooling chamber as a function of air velocity at the moving

plate speed of 2, 5, and 8 cm/s.

Answer #1

After heat treatment, the 2-cm thick metal plates (k = 180
W/m·K, ρ = 2800 kg/m3, and cp = 880 J/kg·K) are conveyed through a
cooling chamber with a length of 10 m. The plates enter the cooling
chamber at an initial temperature of 500°C. The cooling chamber
maintains a temperature of 10°C, and the convection heat transfer
coefficient is given as a function of the air velocity blowing over
the plates h = 33V0.8, where h is in W/m2·K...

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large convection coefficient.
a. Sketch the surface heat flux, q", as a function of time
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Homework-9
Due:
Q) A fuel plate is fabricated from 0.3 cm thick 1.5% enriched
uranium. The cladding is 0.25 mm 304 stainless steel. The coolant
saturation temperature is 260 oC. The
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1014
neutrons/cm2 /s. The surface
temperature of the clad is 350 oC.
Assume any missing data to answer the following questions:.
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1. An oven chimney is
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coefficient is 20 W/m2K;
a) Calculate the shaft exterior
temperature.
b) In order to reduce the risk of burn
injury that may occur in the body, the shaft is asked to be below
55°Cve...

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