Steel balls 12 mm in diameter are annealed by heating to 1150 K and then slowly cooling to 400 K in an air environment for which
T? = 325 K and h = 20 W/m2/K. Assuming the properties of the steel to be k = 40 W/m2K, ? = 7800 kg/m3, and c = 600 J/kg/K, estimate the time required for the cooling process.
1 answer:
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<u></u> has greater effect.
<u>Explanation</u>:
= Temperature of cold reservoir
= Temperature of hot reservoir
when is decreased by 't',
=
when is increased by 'T'
Answer:
power developed by the turbine = 6927.415 kW
Explanation:
given data
pressure = 4 MPa
specific enthalpy h1 = 3015.4 kJ/kg
velocity v1 = 10 m/s
pressure = 0.07 MPa
specific enthalpy h2 = 2431.7 kJ/kg
velocity v2 = 90 m/s
mass flow rate = 11.95 kg/s
solution
we apply here thermodynamic equation that
energy equation that is
put here value with
turbine is insulated so q = 0
so here
solve we get
w = 579700 J/kg = 579.7 kJ/kg
and
W = mass flow rate × w
W = 11.95 × 579.7
W = 6927.415 kW
power developed by the turbine = 6927.415 kW