Evaluating Heat Transfer

The outer surface of the grill hood shown in Fig. P2.52 is at 47°C and the emissivity is 0.93. The heat transfer coefficient for convection between the hood and the surroundings at 27°C is 10 W/m2 · K. Determine the net rate of heat transfer between the grill hood and the surroundings by convection and radiation, in kW per m2 of surface area.

Fig. P2.52

Solution 52P

Step 1 of 5</p>

Here we need to calculate the net rate of heat transfer by convection and radiation between the surrounding and grill hood.

The grill hood’s has its outer surface temperature at with emissivity . The heat coefficient is given to be for the convection heat transfer between the grill hood and surrounding which is at .

Step 2 of 5</p>

Given data,

Outer surface temperature atUsing

Surrounding ,Using

Emissivity, Heat coefficient, Stefan Boltzmann Constant,To find,

Rate of heat transfer through convection =?

Rate of heat transfer through radiation =?

Total Net Rate of heat transfer =?

Step 3 of 5</p>To calculate the rate of heat transfer through convection,

The rate of heat transfer through convection is given by,

Substituting , and