Answer:
a) Power developed by the turbine = 132.89 kW
b) magnitude of the rate of heat transfer from the air to the ambient, in kw = 251.25 kW
Explanation:
b) The process is a constant pressure process (Isobaric process)
The constant pressure specific heat of air,
Specific heat ratio for air,
The mass flow rate of air,
P₁ = 2.5 bar, T₁ = 400 K
P₂ = 2.5 bar, T₂ = 300 K
Using the steady flow energy equation:
Therefore, the magnitude of the rate of heat transfer from the air to the ambient, in kw,
a) For the isentropic process:
Power developed by the turbine is given by the relation
Isentropic efficiency,
P₂ = 2.5 bar, T₂ = 300 K
P₃ = 1 bar, = ? where
is the isentropic temperature at 100% efficiency
The isentropic relation is given by:
To get the temperature at 80% efficiency, we will use the relation:
T₃ = 244.72 K
Power developed by the turbine is given by the relation: