Answer to Question #269358 in Molecular Physics | Thermodynamics for Manish kumar

Question

In a centrifugal compressor suction and delivery pressure are 100 kpa and 550 kpa respectively .The compressor draws 15m3/kg .Find increase in internal energy per kg of air

Answer 1

Solution;

Given;

P₁=100kPa

P₂=550kPa

v=15m³/kg

Take R=0.287kJ/kgK

From;

$Pv=RT$

We can find the temperatures;

$T_1=\frac{PV}{R}=\frac{100×15}{0.287}=5226K$

$T_2=\frac{550×15}{0.287}=28745.6446K$

Increase in international Energy ,U;

$\Delta u=nc_v\Delta T$

$c_v=0.718kJ/kgK$

$\Delta u=0.718(28745.64-5226)=16887.1kJ/kg$