Chapter 7, Problem 7.23P

Interpretation Introduction

Interpretation:

In an adiabatic turbine for ideal gas (Nitrogen) with a constant heat capacity find out actual power output, rate entropy and turbine efficiency.

Concept introduction:

For a steady state adiabatic turbine, its in and out pressures are fixed. Hence, an isentropic process of turbine is called idealized process. There is no heat transfer occur in the turbine, which indicates that work output is the desired output from a turbine.

Power output from turbine during expansion:

  $W=\eta \stackrel{.}{m}{C}_P{T}_1\left[{\left(\frac{P_2}{P_1}\right)}^{\frac{R}{C_P}}-1\right]$

Rate of entropy generation:

  $\Delta S=C_P\left(\ln \left(\frac{T_2}{T_1}\right)\right)-R\left(\ln \left(\frac{P_2}{P_1}\right)\right)$